Communication method and apparatus

Abstract

A communication method and apparatus, which enable communication between an RAN and a second network by means of the forwarding of a first network. A network element in the first network (e.g., a ToC network) may allocate routing information to a network element in the second network (e.g., a ToB network) and return the routing information to the RAN. Subsequently, when the RAN needs to send signaling / data to the second network, the RAN may send to the network element in the first network a message, which carries the routing information of the network element in the second network, and the signaling / data to be sent to the second network, such that the network element in the first network forwards, to the second network on the basis of the routing information, the signaling / data to be sent to the second network. That is, the present application enables communication between the RAN and the second network by means of the forwarding of the first network, thereby enabling communication between an access network element and the network element in the second network, and further supporting diverse user requirements for a subnet, such as supporting increasingly stringent mobility requirements for the subnet, and thus improving the user experience.

Description

Communication methods and devices

[0001] This application claims priority to Chinese Patent Application No. 202510093147.8, filed on January 20, 2025, entitled "Communication Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more particularly to communication methods and apparatus. Background Technology

[0003] As user demands in enterprise (ToB) scenarios increase, the need for distributed ToB networks is also growing stronger. To address the requirement that ToB data should not leave the campus—namely, privacy and security—fifth-generation (5G) mobile communication systems achieve this by physically deploying user plane function (UPF) network elements.

[0004] However, as the mobility requirements of ToB networks become increasingly stringent, such as requiring short handover latency and ensuring that user behavior in distributed ToB networks is not perceived by consumer-facing (ToC) networks, ToB networks also need mobility management (MM) network elements, and even session management (SM) network elements. This means that in addition to the deployment of UPF (User Provider Function) infrastructure, the MM / SM of ToB networks also need to be separated from and deployed to the ToC network.

[0005] In this scenario, how to achieve communication between the radio access network (RAN) and the ToB network is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a communication method and apparatus that enables communication between the RAN and a second network through forwarding in a first network.

[0007] Firstly, a communication method is provided. This method can be executed by a first control plane network element, or by a component of the first control plane network element, such as a processor, chip, or chip system of the first control plane network element, or by a logic module or software capable of implementing all or part of the functions of the first control plane network element. The first control plane network element is deployed in a first network. The method includes: receiving a service request message from an access network element, the service request message being used to request access to a service in a second network; obtaining routing information of a second control plane network element and routing information of a second user plane network element according to the service request message; and sending the routing information of the second control plane network element and the routing information of the second user plane network element to the access network element. The second control plane network element and the second user plane network element are deployed in a second network.

[0008] Based on this scheme, the first control plane network element in the first network can obtain the routing information of the second control plane network element and the second user plane network element in the second network, and return the routing information of the second control plane network element and the second user plane network element to the access network element. This enables the access network element to send a message to the first control plane network element / first user plane network element in the first network when it needs to send signaling / data to the second network. The message carries the routing information of the second control plane network element / second user plane network element, so that the first control plane network element / first user plane network element can forward the signaling / data to be sent to the second network to the second control plane network element / second user plane network element according to the routing information. This realizes the communication between the access network element and the network elements in the second network, thereby supporting various user needs for the second network, such as supporting increasingly higher mobility requirements of the second network and improving the user experience.

[0009] In one possible design, obtaining routing information of the second control plane network element and routing information of the second user plane network element includes: allocating routing information of the second control plane network element to the second control plane network element; sending a first request message to the first user plane network element, the first request message being used to request routing information of the second user plane network element, the first user plane network element being deployed in the first network; and receiving routing information of the second user plane network element from the first user plane network element.

[0010] Based on this possible design, the routing information of the control plane network elements of the second network is allocated by the control plane network elements of the first network, and the routing information of the user plane network elements of the second network is allocated by the user plane network elements of the first network. This can support scenarios where signaling of the second network is forwarded through the control plane of the first network and data of the second network is forwarded through the user plane of the first network. This avoids scenarios where the routing information of the control plane network elements and user plane network elements of the second network are allocated by the control plane network elements of the first network, or all of them are allocated by the user plane network elements of the first network. This can improve the accuracy of the routing information of the network elements of the second network, thereby ensuring the correct routing of signaling / data of the second network and improving transmission efficiency.

[0011] In one possible design, the method further includes: establishing a first connection, which is a connection between a first control plane network element and a second control plane network element; the connection between the access network element and the second control plane network element includes the first connection and a third connection, which is a connection between the access network element and the first control plane network element; the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, or includes the identifier of the connection between the access network element and the second control plane network element.

[0012] In one possible design, the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, or includes the identifier of the connection between the access network element and the second user plane network element; wherein, the second connection is the connection between the first user plane network element and the second user plane network element, the fourth connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second user plane network element includes the second connection and the fourth connection.

[0013] Based on the two possible designs mentioned above, routing can be performed by identifying the connection between the access network element and the network element of the first network, as well as the connection between the network element of the first network and the network element of the second network. This enables the forwarding of signaling from the control plane network element of the first network to the second network, and the forwarding of data from the user plane network element of the first network to the second network.

[0014] In one possible design, obtaining routing information for the second control plane network element and routing information for the second user plane network element includes: allocating routing information for the second control plane network element and allocating routing information for the second user plane network element. For example, the routing information for the second control plane network element is the identifier of the second control plane network element, and the information for the second user plane network element is the identifier of the second user plane network element.

[0015] In one possible design, the method further includes: sending routing information of a second user plane network element to a first user plane network element, wherein the first user plane network element is deployed in a first network.

[0016] Based on this possible design, the first control plane network element sends the routing information of the second user plane network element to the first user plane network element, enabling the first user plane network element to forward data of the second network based on the routing information of the second user plane network element, thereby realizing data communication between the access network and the second network.

[0017] In one possible design, the method further includes: sending routing information of the second control plane network element and the second user plane network element to the first user plane network element, wherein the first user plane network element is deployed in the first network.

[0018] Based on this possible design, the first control plane network element sends routing information of the second control plane network element and the second user plane network element to the first user plane network element, enabling the first user plane network element to forward signaling of the second network based on the routing information of the second control plane network element, and to forward data of the second network based on the information of the second user plane network element, thereby realizing signaling and data communication between the access network and the second network.

[0019] In one possible design, obtaining routing information of the second control plane network element and routing information of the second user plane network element includes: sending a second request message to a first user plane network element, the second request message being used to request routing information of the second control plane network element and routing information of the second user plane network element, the first user plane network element being deployed in a first network; and receiving routing information of the second control plane network element and routing information of the second user plane network element from the first user plane network element.

[0020] Based on this possible design, the routing information of the control plane network elements and user plane network elements of the second network can be allocated by the user plane network elements of the first network. This can support scenarios where signaling and data of the second network are forwarded through the user plane of the first network. It can improve the accuracy of the routing information of the network elements of the second network in this scenario, thereby ensuring the correct routing of signaling / data of the second network and improving transmission efficiency.

[0021] In one possible design, the routing information of the second control plane network element includes the identifier of the fifth connection and the identifier of the seventh connection, or includes the identifier of the connection between the access network element and the second control plane network element; wherein, the fifth connection is the connection between the first user plane network element and the second control plane network element, the seventh connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second control plane network element includes the fifth connection and the seventh connection.

[0022] In one possible design, the routing information of the second user plane network element includes the identifiers of the sixth connection and the eighth connection, or the identifiers of the connection between the access network element and the second user plane network element; wherein, the sixth connection is the connection between the first user plane network element and the second user plane network element, the eighth connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second user plane network element includes the sixth connection and the eighth connection.

[0023] Based on the two possible designs mentioned above, routing can be performed by identifying the connection between the access network element and the network element of the first network, as well as the connection between the network element of the first network and the network element of the second network, thereby enabling the user plane network element of the first network to forward signaling and data to the second network.

[0024] In one possible design, the method further includes: receiving signaling from an access network element and routing information of the signaling, wherein the routing information of the signaling is used to route the signaling to a second control plane element; and determining, based on the routing information of the signaling, to send the signaling to the second control plane element.

[0025] In one possible design, if the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, determining to send the signaling to the second control plane network element based on the routing information of the signaling includes: if the routing information of the signaling includes the identifier of the third connection, or if it includes the identifier of the first connection and the identifier of the third connection, determining to send the signaling to the second control plane network element.

[0026] In one possible design, receiving signaling and routing information of the signaling from an access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, the source IP address of the first message being the IP address of the access network element; the method further includes: sending a third message to a second control plane element according to a first connection mapping relationship, the third message including the signaling; wherein, the first connection mapping relationship includes the IP address of the access network element and the identifier of the third connection, a mapping relationship between the identifier of the first connection and the IP address of the second control plane element, and the destination IP address of the third message being the IP address of the second control plane element.

[0027] In one possible design, if the routing information of the second control plane network element includes the port number of the second control plane network element, determining to send the signaling to the second control plane network element based on the routing information of the signaling includes: if the routing information of the signaling indicates that the destination port number of the signaling is the port number of the second control plane network element, determining to send the signaling to the second control plane network element.

[0028] In one possible design, receiving signaling and routing information of the signaling from an access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, the destination IP address of the first message being the IP address of a first control plane network element; the method further includes: sending a third message to a second control plane network element according to a first Network Address Translation (NAT) mapping relationship, the third message including the signaling; wherein, the first NAT mapping relationship includes the mapping relationship between the IP address of the first control plane network element and the port number of the second control plane network element, and the IP address of the second control plane network element, and the destination IP address of the third message is the IP address of the second control plane network element.

[0029] In one possible design, if the routing information of the second control plane network element includes the identifier of the second control plane network element, determining to send the signaling to the second control plane network element based on the routing information of the signaling includes: if the routing information of the signaling includes the identifier of the second control plane network element, determining to send the signaling to the second control plane network element.

[0030] In one possible design, receiving signaling and routing information of the signaling from an access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, the destination IP address of the first message being the IP address of a first control plane network element; the method further includes: sending a third message to a second control plane network element according to a first identifier mapping relationship, the third message including the signaling; wherein, the first identifier mapping relationship includes the mapping relationship between the IP address of the first control plane network element and the identifier of the second control plane network element, and the IP address of the second control plane network element, and the destination IP address of the third message is the IP address of the second control plane network element.

[0031] Secondly, a communication method is provided. This method can be executed by an access network element, or by a component of the access network element, such as a processor, chip, or chip system of the access network element, or by a logic module or software capable of implementing all or part of the functions of the access network element. The method includes: receiving first information and network indication information from a first terminal, wherein the network indication information indicates that the first information is to be sent to a second network. If the first information is signaling, the method sends the signaling and its routing information to a first control plane network element or a first user plane network element, wherein the routing information is used to route the signaling to a second control plane network element; or, if the first information is data, the method sends the data and its routing information to a first user plane network element; wherein the first control plane network element and the first user plane network element are deployed in a first network, and the second control plane network element and the second user plane network element are deployed in a second network.

[0032] Based on this scheme, upon receiving signaling / data to be sent to the second network, the access network element can send the signaling / data and its routing information to the network elements in the first network. The routing information of the signaling / data is used to route the signaling / data to the control plane network elements / user plane network elements in the second network. This allows the network elements in the first network to forward the signaling / data to be sent to the second network to the second control plane network elements / second user plane network elements according to the routing information of the signaling / data. This enables communication between the access network element and the network elements in the second network, thereby supporting various user needs for the second network, such as supporting increasingly higher mobility requirements of the second network and improving user experience.

[0033] In one possible design, before receiving the first information and network indication information from the first terminal, the method further includes: receiving a service request message from the first terminal, the service request message being used to request access to a service in the second network; sending the service request message to a first control plane network element; receiving routing information from the first control plane network element, routing information from a second control plane network element, and routing information from a second user plane network element, the routing information from the second control plane network element being used to determine the routing information of the aforementioned signaling, and the routing information from the second user plane network element being used to determine the routing information of the aforementioned data; and sending a service response message to the first terminal, the service response message being used to indicate permission to access the service in the second network.

[0034] In one possible design, the network indication information includes at least one of the following: the identifier of the second network, the terminal identifier of the first terminal in the second network, the IP address of the first terminal in the second network, the identifier of the second service, the routing information of the second control plane network element, or the routing information of the second user plane network element; wherein, the second service is the service requested by the first terminal, and the second service is a service in the second network.

[0035] In one possible design, the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, or includes the identifier of the connection between the access network element and the second control plane network element; wherein, the first connection is the connection between the first control plane network element and the second control plane network element, the identifier of the third connection is the connection between the access network element and the first control plane network element, and the connection between the access network element and the second control plane network element includes the first connection and the third connection.

[0036] In one possible design, the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, or includes the identifier of the connection between the access network element and the second user plane network element; wherein, the second connection is the connection between the first user plane network element and the second user plane network element, the fourth connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second user plane network element includes the second connection and the fourth connection.

[0037] In one possible design, the routing information of the second control plane network element includes the identifier of the fifth connection and the identifier of the seventh connection, or includes the identifier of the connection between the access network element and the second control plane network element; wherein, the fifth connection is the connection between the first user plane network element and the second control plane network element, the seventh connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second control plane network element includes the fifth connection and the seventh connection.

[0038] In one possible design, the routing information of the second user plane network element includes the identifiers of the sixth connection and the eighth connection, or the identifiers of the connection between the access network element and the second user plane network element; wherein, the sixth connection is the connection between the first user plane network element and the second user plane network element, the eighth connection is the connection between the access network element and the first user plane network element, and the connection between the access network element and the second user plane network element includes the sixth connection and the eighth connection.

[0039] In one possible design, if the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, then the routing information of the aforementioned signaling includes the identifier of the third connection, or includes the identifier of the third connection and the identifier of the first connection.

[0040] In one possible design, if the routing information of the second control plane network element includes the identifier of the fifth connection and the identifier of the seventh connection, then the routing information of the aforementioned signaling includes the identifier of the seventh connection, or includes the identifier of the seventh connection and the identifier of the fifth connection.

[0041] In one possible design, if the routing information of the second control plane network element includes the port number of the second control plane network element, the routing information of the aforementioned signaling indicates that the destination port of the signaling is the port number of the second control plane network element.

[0042] In one possible design, where the routing information of the second control plane network element includes the identifier of the second control plane network element, the routing information of the aforementioned signaling includes the identifier of the second control plane network element.

[0043] In one possible design, if the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, then the routing information of the aforementioned data includes the identifier of the fourth connection, or includes the identifier of the fourth connection and the identifier of the second connection.

[0044] In one possible design, if the routing information of the second user plane network element includes the identifier of the sixth connection and the identifier of the eighth connection, then the routing information of the aforementioned data includes the identifier of the eighth connection, or includes the identifier of the eighth connection and the identifier of the sixth connection.

[0045] In one possible design, if the routing information of the second user plane network element includes the port number of the second user plane network element, the routing information of the aforementioned data indicates that the destination port of the data is the port number of the second user plane network element.

[0046] In one possible design, if the routing information of the second user plane network element includes the identifier of the second user plane network element, then the routing information of the aforementioned data includes the identifier of the second user plane network element.

[0047] In one possible design, the method further includes: finding routing information of a second control plane network element and / or routing information of a second user plane network element based on network indication information, wherein the routing information of the second control plane network element is used to determine the routing information of signaling, and the routing information of the second user plane network element is used to determine the routing information of data.

[0048] In one possible design, if the network indication information includes the terminal identifier of the first terminal in the second network, the routing information of the second control plane network element and / or the routing information of the second user plane network element is searched in the first routing mapping table. The first routing mapping table includes the terminal identifier of the first terminal in the second network and the mapping relationship between it and the routing information of the second control plane network element and / or the routing information of the second user plane network element. Alternatively, if the network indication information includes the identifier of the second service, the routing information of the second control plane network element and / or the routing information of the second user plane network element is searched in the second routing mapping table. The second routing mapping table includes the identifier of the second service and the mapping relationship between it and the routing information of the second control plane network element and / or the routing information of the second user plane network element.

[0049] The technical effects of any possible design in the second aspect can be referred to the technical effects of the corresponding design in the first aspect above, and will not be repeated here.

[0050] Thirdly, a communication method is provided. This method can be executed by a first terminal, or by a component of the first terminal, such as a processor, chip, or chip system, or by a logic module or software capable of implementing all or part of the functions of the first terminal. The first terminal is deployed in a first network. The method includes: generating first information, where the first information is control signaling for a service or service data for that service; and sending the first information and network indication information to an access network element. Wherein, if the service is a first service in the first network, the network indication information indicates that the first information is to be sent to the first network; or, if the service is a second service in a second network, the network indication information indicates that the first information is to be sent to the second network.

[0051] Based on this scheme, the first terminal can indicate to the access network element whether the first information is to be sent to the first network or the second network. Therefore, when the access network element sends the first information to the core network, it can carry corresponding routing information based on this indication. For example, when the first information is to be sent to the second network, it can carry routing information for routing the first information to network elements in the second network. This allows network elements in the first network to send the first information to network elements in the second network based on the routing information of the first information, thereby realizing communication between the access network element and network elements in the second network. This supports various user needs for the second network, such as supporting increasingly higher mobility requirements for the second network and improving user experience.

[0052] In one possible design, when the service is a second service in a second network, the network indication information includes at least one of the following: the identifier of the second network, the terminal identifier of the first terminal in the second network, the IP address of the first terminal in the second network, the identifier of the second service, the routing information of the second control plane network element, or the routing information of the second user plane network element; wherein the second control plane network element and the second user plane network element are deployed in the second network.

[0053] In one possible design, the method further includes: determining whether the service is a first service in a first network or a second service in a second network based on the mapping relationship between services and networks.

[0054] In one possible design, if the service is determined to be a second service in a second network, the method further includes: sending a service request message to an access network element, the service request message being used to request access to the service in the second network; and receiving a service response message from the access network element, the service response message being used to indicate that access to the service in the second network is permitted.

[0055] Fourthly, a communication device is provided for implementing various methods. The communication device includes modules, units, or means corresponding to the implementation of the methods, wherein the modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the functions.

[0056] In some possible designs, the communication device may include a processing module and a transceiver module. The processing module can be used to implement the processing functions in any of the above aspects and any possible implementations thereof. The transceiver module may include a receiving module and a transmitting module, respectively used to implement the receiving function and the transmitting function in any of the above aspects and any possible implementations thereof.

[0057] In some possible designs, the transceiver module can consist of transceiver circuits, transceivers, transceivers, or communication interfaces.

[0058] Fifthly, a communication device is provided, comprising: a processor and a memory; the memory being used to store computer instructions that, when executed by the processor, cause the communication device to perform the method described in any of the above aspects and any possible design thereof.

[0059] A sixth aspect provides a communication device, comprising: a processor and a communication interface; the communication interface being used to communicate with a module outside the communication device; the processor being used to execute computer programs or instructions to cause the communication device to perform the methods described in any of the above aspects and any possible designs thereof.

[0060] A seventh aspect provides a communication device comprising: at least one processor; said processor being configured to execute a computer program or instructions stored in a memory to cause the communication device to perform the methods described in any of the foregoing aspects and any possible designs thereof. The memory may be coupled to the processor, or may be independent of the processor.

[0061] Eighthly, a communication device (e.g., a chip or chip system) is provided, the communication device including a processor for implementing the functions involved in any of the preceding aspects.

[0062] In some possible designs, the communication device includes a memory for storing necessary program instructions and data.

[0063] In some possible designs, when the device is a chip system, it can be composed of chips or contain chips and other discrete components.

[0064] The communication device described in the fourth to eighth aspects may be a first control plane network element in the first aspect, or a device contained in the first control plane network element, such as a chip or chip system; or, the communication device may be an access network element in the second aspect, or a device contained in the access network element, such as a chip or chip system; or, the communication device may be a first terminal in the third aspect, or a device contained in the first terminal, such as a chip or chip system.

[0065] A ninth aspect provides a communication device, which may be a first control plane network element, or a module or unit (e.g., a chip, chip system, or circuit) in the first control plane network element that performs the methods / operations / steps / actions described in the first aspect, or a module or unit that can be used in conjunction with a terminal device; or, the communication device may be an access network element, or a module or unit (e.g., a chip, chip system, or circuit) in the access network element that performs the methods / operations / steps / actions described in the second aspect, or a module or unit that can be used in conjunction with an access network element; or, the communication device may be a first terminal, or a module or unit (e.g., a chip, chip system, or circuit) in the first terminal that performs the methods / operations / steps / actions described in the third aspect, or a module or unit that can be used in conjunction with a first terminal.

[0066] It is understandable that when the communication device provided in any of the fourth to ninth aspects is a chip, the sending action / function of the communication device can be understood as outputting information, and the receiving action / function of the communication device can be understood as inputting information.

[0067] In a tenth aspect, a computer-readable storage medium is provided that stores a computer program or instructions that, when executed on a communication device, enable the communication device to perform the methods described in any of the above aspects and any possible designs thereof.

[0068] In an eleventh aspect, a computer program product containing instructions is provided, which, when run on a communication device, enables the communication device to perform the methods described in any of the above aspects and any possible designs thereof.

[0069] In a twelfth aspect, a communication system is provided, which may include a first control plane network element, an access network element, and a first terminal. The first control plane network element is used to implement the method described in the first aspect and any of its design embodiments, the access network element is used to implement the method described in the second aspect and any of its design embodiments, and the first terminal is used to implement the method described in the third aspect and any of its design embodiments.

[0070] The technical effects of any of the design methods in aspects four through twelfth can be found in the technical effects of different design methods in aspects one, two, or three, and will not be repeated here. Attached Figure Description

[0071] Figure 1 is a schematic diagram of a single-SIM single-network or dual-SIM dual-network scenario provided in this application;

[0072] Figure 2 is a schematic diagram of a single-card dual-network network architecture provided in this application;

[0073] Figure 3 is a schematic diagram of the structure of a communication system provided in this application;

[0074] Figures 4-6 are schematic diagrams of the transmission path when forwarding signaling or data through a large network as provided in this application;

[0075] Figures 7-9 are schematic flowcharts of the communication method provided in this application;

[0076] Figures 10 and 11 are schematic diagrams of the protocol stack architecture provided in this application;

[0077] Figures 12 and 13 are schematic diagrams of signaling / data encapsulation provided in this application;

[0078] Figure 14 is a flowchart illustrating a communication method provided in this application;

[0079] Figures 15 and 16 are schematic diagrams of the protocol stack architecture provided in this application;

[0080] Figures 17 and 18 are schematic diagrams of signaling / data encapsulation provided in this application;

[0081] Figures 19 and 20 are schematic flowcharts of the communication method provided in this application;

[0082] Figure 21 is a schematic diagram of a protocol stack architecture provided in this application;

[0083] Figures 22 and 23 are schematic diagrams of signaling / data encapsulation provided in this application;

[0084] Figure 24 is a flowchart illustrating a communication method provided in this application;

[0085] Figures 25 and 26 are schematic diagrams of signaling / data encapsulation provided in this application;

[0086] Figure 27 is a flowchart illustrating a communication method provided in this application;

[0087] Figures 28 and 29 are schematic diagrams of the structure of a communication device provided in this application. Detailed Implementation

[0088] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0089] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0090] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0091] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0092] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0093] It is understood that in this application, "...when" and "if" both refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed during implementation, nor do they imply any other limitations.

[0094] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0095] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, and in the various implementation methods / methods / implementations within each embodiment, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the various implementation methods / methods / implementations within each embodiment are consistent and can be mutually referenced. The technical features in different embodiments and the various implementation methods / methods / implementations within each embodiment can be combined according to their inherent logical relationships to form new embodiments, implementation methods, methods, or implementation approaches. The embodiments described below do not constitute a limitation on the scope of protection of this application.

[0096] In fifth-generation (5G) mobile communication systems, terminals only support single-SIM single-network access. For example, a terminal can access the main network via a single subscriber identity module (SIM) card, or access a subnet via a single SIM card. Exemplarily, the main network can be a consumer-facing (ToC) network (which can be simply referred to as a ToC network), and the subnet can be a business-facing (ToB) network (which can be simply referred to as a ToB network). The main network and subnet can also be other types of networks, or have other names without limitation.

[0097] For example, in the single-card single-network access mode, as shown in Figure 1(a), the terminal accesses the core network (CN) of the large network through the radio access network (RAN); as shown in Figure 1(b), the terminal accesses the subnet (CN) through the subnet (RAN).

[0098] If a single terminal has both main network and subnet services, it needs to use dual SIM cards to access them. For example, SIM 1 accesses the main network, and SIM 2 accesses the subnet, which is a dual-SIM dual-network access method. In this scenario, as shown in Figure 1(c), the subnet CN can be deployed within the main network CN, and both share the main network RAN; or, as shown in Figure 1(d), the subnet CN and the main network CN are deployed independently, as are the subnet RAN and the main network RAN. The terminal uses one SIM card to access the main network CN through the main network RAN ​​and uses another SIM card to access the subnet CN through the subnet RAN.

[0099] In other words, currently only single-SIM single-network and dual-SIM dual-network access methods are supported. Furthermore, with the increasing communication demands of ToB businesses, the need for distributed ToB networks is also growing stronger. For example, ToB networks require higher privacy and security, which can be achieved by deploying user plane function (UPF) network elements physically.

[0100] However, as the mobility requirements of ToB networks become increasingly stringent, ToB networks also need mobility management (MM) network elements, and even session management (SM) network elements. This means that in addition to the deployment of UPF (User-Defined Provider Interface), the MM / SM of ToB networks also need to be separated from and deployed to the ToC network.

[0101] Based on this, this application proposes a single-SIM dual-network architecture, which can include the three implementation methods shown in Figure 2. As shown in Figure 2(a), the subnet CN is deployed in a decentralized manner (e.g., the subnet UPF is deployed in a decentralized manner), the subnet CN and the main network CN share the RAN, but there is no direct connection between the subnet CN and the RAN; communication between the RAN and the subnet CN is forwarded through the main network CN. Alternatively, as shown in Figure 2(b), the subnet CN is deployed in a decentralized manner (e.g., both the subnet UPF and control plane network elements are decentralized), the subnet CN and the main network CN share the RAN. Alternatively, as shown in Figure 2(c), the subnet CN and the main network CN are deployed independently, and the subnet RAN and the main network RAN ​​are also deployed independently. The terminal uses a single SIM card to access the main network CN through the main network RAN ​​via dual registration, and accesses the subnet CN through the subnet RAN.

[0102] Furthermore, some areas may lack subnet RAN coverage, while others may lack mainnet RAN coverage. In this scenario, the network deployment architecture of the single-SIM dual-network terminal may differ as the terminal moves. For example, as shown in Figure 2(d), if the terminal initially accesses the subnet CN via the subnet RAN and then the mainnet CN via the mainnet RAN, and after a period of time moves to an area without subnet RAN coverage, the network architecture becomes subnet CN and mainnet CN sharing the mainnet RAN. After another period of time, the terminal may move to an area without mainnet RAN coverage, and the network architecture becomes subnet CN and mainnet CN sharing the subnet RAN.

[0103] Under the network architecture shown in Figure 2 above, there may be scenarios where the interaction between the RAN and the subnet CN requires forwarding by the main network CN. Therefore, how to realize the forwarding of information between the RAN and the subnet CN by the main network CN is an urgent problem to be solved.

[0104] Based on this, this application provides a communication method. In this method, network elements in a first network (such as a ToC network) can allocate routing information to network elements in a second network (such as a ToB network), including control plane and user plane network elements, and return this information to the RAN. Subsequently, when the RAN needs to send signaling / data to the second network, it can send a message to a network element in the first network carrying the routing information of the network element in the second network and the signaling / data to be sent to the second network. This allows the network element in the first network to forward the signaling / data to the second network based on the routing information. In other words, based on the solution of this application, communication between the RAN and the second network can be achieved through forwarding in the first network, thereby supporting the separation of the core network elements of the second network from the first network. This enables the fulfillment of various user needs in the second network, such as meeting increasingly higher mobility requirements and improving user experience.

[0105] The technical solutions of this application embodiment can be used in various communication systems, including 3GPP communication systems such as 4th generation (4G) systems (e.g., Long Term Evolution (LTE) systems), 5G systems (e.g., New Radio (NR) systems), LTE and 5G hybrid networking systems, sensing systems, integrated communication and sensing systems, non-terrestrial networks (NTN), device-to-device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, machine-type communication (MTC) systems, Internet of Things (IoT) systems, or other future communication systems. The communication system can also be a non-3GPP communication system; there is no limitation on this.

[0106] The communication systems described above are merely illustrative examples, and are not limited to those described herein. The communication systems provided in this application do not impose any limitations on the solutions described herein. This will be explained uniformly here and will not be repeated below.

[0107] Figure 3 illustrates a possible, non-limiting system diagram. As shown in Figure 3, the communication system 30 includes a radio access network (RAN) 300 and a core network (CN) 400. Optionally, the communication system 30 may also include a data network (DN) (not shown in Figure 3).

[0108] For example, RAN 300 can be a 3GPP-related cellular system, such as a 4G or 5G mobile communication system, an NTN system (e.g., an NTN supporting pass-through mode and / or regenerative mode, or an NTN supporting eye-viewing mode (earth fixed cell) and / or non-eye-viewing mode (earth moving cell), or a future-oriented evolution system. RAN 300 can also be an open access network (open RAN, O-RAN, or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN 300 can also be a communication system integrating two or more of the above systems. Core network 400, as the core part of the mobile communication system, plays a crucial role in connecting the upper and lower layers, mainly responsible for handling terminal mobility management, session management, and data transmission.

[0109] RAN 300 includes at least one access network element (310 in Figure 3) and at least one terminal (320 in Figure 3).

[0110] The core network 400 may include a first network and a second network. The first network deploys a first control plane network element and a first user plane network element, while the second network deploys a second control plane network element and a second user plane network element. The network elements in the core network can be collectively referred to as core network elements. The network elements in the first network can forward signaling and / or data between the RAN and the second network.

[0111] In one possible implementation, the control plane network element in this application can implement at least one of access management (AM), mobility management (MM), or session management (SM). AM is mainly used for access management in mobile networks, MM is mainly used for mobility management in mobile networks, such as user location updates, user network registration, and user handover. SM is mainly used for session management in mobile networks, such as session establishment, modification, and release.

[0112] For example, when a control plane network element is used to implement AM / MM, it can be an access and mobility management function (AMF) network element in a 5G system; when a control plane network element is used to implement SM, it can be a session management function (SMF) network element in a 5G system. In future mobile communication systems, control plane network elements may have other functions and names, and this application does not specifically limit them.

[0113] As one possible implementation, in terms of device form, the control plane network element can be a single entity used to implement at least one of the above functions; or, the control plane network element can be multiple entities, or in other words, the control plane network element includes multiple network elements used to implement at least one of the above functions.

[0114] For example, a first control plane network element may include at least one network element. When a first control plane network element includes multiple network elements, the scheme implemented by the first control plane network element can be implemented by some or all of the multiple network elements included in the first control plane network element, and these multiple network elements can communicate with each other. Furthermore, the inclusion of multiple network elements in a first control plane network element can also be understood as the first control plane network element integrating the functions of multiple network elements, or in other words, the multiple network elements being co-located.

[0115] Similarly, a second control plane network element may include at least one network element. When a second control plane network element includes multiple network elements, the scheme implemented by the second control plane network element described below can be implemented by some or all of the multiple network elements included in the second control plane network element, and these multiple network elements can communicate with each other. Furthermore, the inclusion of multiple network elements in a second control plane network element can also be understood as the second control plane network element integrating the functions of multiple network elements, or in other words, the multiple network elements being co-located.

[0116] In one possible implementation, the user plane network element in this application is primarily responsible for user data processing (forwarding, receiving, billing, etc.). For example, the user plane network element can receive user data from the DN and forward the user data to the terminal through the access network. Alternatively, the user plane network element can receive user data from the terminal through the access network and forward the user data to the DN. The DN can refer to a network that provides data transmission services to users, such as Internet Protocol (IP), IP Multimedia Service (IMS), the Internet, etc. The DN can be an external network of the operator or a network controlled by the operator, used to provide service to terminal devices.

[0117] For example, user plane network elements can implement the functions of UPF network elements in 5G systems. In future mobile communication systems, user plane network elements may have other functions and names, and this application does not specifically limit them.

[0118] As one possible implementation, the first network can be understood as a large network (CN), and the second network can be understood as a subnet (CN). For example, the second network can be understood as a distributed subnet.

[0119] In one possible implementation, the access network element 310 is a network-side device with wireless transceiver capabilities. Access network elements, sometimes also referred to as RAN entities, access nodes, or RAN nodes, constitute part of the communication system and are used to assist terminal devices in achieving wireless access.

[0120] For example, access network elements are mainly responsible for functions related to the air interface. For example, 1) radio link maintenance function, which is used to maintain the radio link with the terminal and is responsible for the protocol conversion between radio link data and IP data; 2) radio resource management function, including the establishment and release of radio links, scheduling and allocation of radio resources, etc.; 3) some mobility management functions, including configuring the terminal to perform measurements, evaluating the quality of the terminal's radio link, and deciding on the handover of the terminal between cells, etc.

[0121] As one possible implementation, the access network element 310 can be an access network device, such as a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a base station evolved by 3GPP, a base station in a future mobile communication system, an access node in a WiFi system, a wireless relay node, a wireless backhaul node, etc.

[0122] As another possible implementation, the access network element 310 can be a node in an O-RAN system. For example, the access network element can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), a radio unit (RU), etc.

[0123] For example, the CU and DU respectively implement some of the protocol layer functions of the access network device. For instance, some protocol layer functions are implemented in the CU, and the remaining or all protocol layer functions are implemented in the DU. The CU can control one or more DUs.

[0124] For example, a CU can deploy the radio resource control (RRC) layer, the service data adaptation protocol (SDAP) layer, and the packet data convergence protocol (PDCP) layer. In other words, the CU can be understood as a logical node carrying the RRC, SDAP, and PDCP layers of the access network equipment. Therefore, the CU has the processing capabilities of the RRC, PDCP, and SDAP layers. Of course, the CU can also implement or carry other control functions. A DU can deploy the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. In other words, the DU can be understood as a logical node carrying the RLC, MAC, and PHY layers. Therefore, the DU has the processing capabilities of the RLC, MAC, and PHY layers. Of course, the DU can also implement or carry other functions.

[0125] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU.

[0126] In one possible implementation, terminal 320 is a user-side device with wireless transceiver capabilities. It can be a fixed device, mobile device, handheld device (e.g., mobile phone), wearable device, in-vehicle device, or a wireless device (e.g., communication module, modem, or chip system, etc.) built into the aforementioned devices. Terminal devices are used to connect people, objects, and machines, and can be widely used in various scenarios, such as: cellular communication, D2D communication, V2X communication, MTC communication, IoT, virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, etc. For example, the terminal device can be a handheld terminal in cellular communication, a communication device in D2D, an IoT device in MTC, a camera in intelligent transportation and smart cities, or a communication device on a drone, etc.; or, the terminal device can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the device form of the terminal device. The terminal device may sometimes be referred to as UE, user terminal, user device, user unit, user station, terminal equipment, access terminal, access station, UE station, remote station, mobile device, or wireless communication device, etc.

[0127] All or part of the functions of the terminal, access network element, or core network element in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform), or through software modules, hardware modules, or a combination of software modules and hardware modules.

[0128] It should be noted that the system described in the embodiments of this application is for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and does not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0129] The communication method provided in this application will be described below with reference to the communication system shown in Figure 3, taking the interaction between the terminal and network elements as an example. It should be noted that in the following embodiments of this application, the message names, parameter names, or information names between the terminal and various network elements are just examples, and other names may be used in other embodiments. The method provided in this application does not specifically limit these names.

[0130] It is understood that in the embodiments of this application, the executing entity may perform some or all of the steps in the embodiments of this application. These steps or operations are merely examples, and the embodiments of this application may also perform other operations or variations thereof. Furthermore, the various steps may be executed in different orders as presented in the embodiments of this application, and it is not necessarily necessary to execute all the operations in the embodiments of this application.

[0131] It is understood that this application uses terminals and network elements as examples to illustrate the execution of the interaction, but this application does not limit the execution subject of the interaction. For example, the method executed by the access network element in this application can also be executed by a module (e.g., chip, chip system, or processor) applied to the access network element, or by a logical node, logical module, or software that can implement all or part of the access network element's functions; the method executed by the terminal in this application can also be executed by a module (e.g., chip, chip system, or processor) applied to the terminal, or by a logical node, logical module, or software that can implement all or part of the terminal's functions; the method executed by the core network element in this application can also be executed by a module (e.g., chip, chip system, or processor) applied to the core network element, or by a logical node, logical module, or software that can implement all or part of the core network element's functions.

[0132] Before describing the communication method provided in this application, we will first describe the forwarding scenario between the first network and the second network provided in this application.

[0133] Scenario 1: Signaling from the second network is forwarded through the control plane of the first network, and data from the second network is forwarded through the user plane of the first network.

[0134] For example, taking the first control plane network element as the AMF network element, the first user plane network element as UPF1, and the second network including subnet 1 and subnet 2, with the second control plane network element in subnet 1 being MM2 and the second user plane network element being UPF2, and the second control plane network element in subnet 2 being MM3 and the second user plane network element being UPF3, as shown in Figure 4, after the terminal's signaling / data is sent to the RAN, the RAN sends the signaling to the AMF, and the AMF forwards the signaling to MM2 in subnet 1 or MM3 in subnet 2; or, the RAN sends the data to UPF1, and UPF1 forwards the data to UPF2 in subnet 1 or UPF3 in subnet 2.

[0135] Alternatively, taking MM1 as the first control plane network element, UPF1 as the first user plane network element, MM2 as the second control plane network element, and UPF2 as the second user plane network element as an example, as shown in Figure 5, signaling is forwarded from MM1 to MM2, and from UPF1 to UPF2. Furthermore, the first network may also include SM1, with a connection between SM1 and UPF1; the second network may also include SM2, with a connection between SM2 and UPF2. UPF1 can be connected to DN1, and UPF2 can be connected to DN2.

[0136] Scenario 2: Signaling and data from the second network are forwarded through the user plane of the first network. That is, all signaling and data from the second network are forwarded through the user plane of the first network.

[0137] For example, taking the first control plane network element as the AMF network element, the first user plane network element as UPF1, and the second network including subnet 1 and subnet 2, with the second control plane network element in subnet 1 being MM2 and the second user plane network element being UPF2, and the second control plane network element in subnet 2 being MM3 and the second user plane network element being UPF3, as shown in Figure 6, after the terminal's signaling and data are sent to the RAN, the RAN sends the signaling and data to UPF1. UPF1 forwards the signaling to MM2 in subnet 1 or MM3 in subnet 2; or, UPF1 forwards the data to UPF2 in subnet 1 or UPF3 in subnet 2. Here, UPF1 can also be understood or replaced as a signaling / data broker deployed in the first network.

[0138] The communication method provided in the embodiments of this application will be described below. Unless otherwise specified, the methods provided in the following embodiments can be applied to either scenario one or scenario two described above.

[0139] Figure 7 shows a flowchart of a communication method provided in this application. The communication method may include the following steps:

[0140] S700, The first terminal generates first information. The first information is either control signaling for the service or service data for that service.

[0141] As one possible implementation, the first terminal can determine whether the service belongs to the first network or the second network based on the mapping relationship between services and networks. For ease of description, the service can be referred to as the first service when it belongs to the first network, and as the second service when it belongs to the second network.

[0142] The mapping relationship between services and networks indicates the services provided by the network. Specifically, this mapping relationship can be a mapping relationship between a network identifier and a service identifier provided by the network. For example, this mapping relationship includes a mapping relationship between the identifier of a first network and the identifier of a service provided by the first network, and also includes the identifier of a second network and the identifier of a service provided by the second network. Thus, the first terminal can determine whether the aforementioned service is a service in the first network or a service in the second network based on the mapping relationship between services and networks. In the following embodiments of this application, the example of the service being a service in the second network is used for illustration.

[0143] As one possible implementation, step S700 can also be replaced by: the first terminal determining the service to be accessed, and determining, based on the mapping relationship between services and networks, whether the service to be accessed is a first service in a first network or a second service in a second network. In this case, the first information can be understood as the control signaling or service data of the service to be accessed. The first terminal can generate the first information before step SS705; this application does not specifically limit the timing of the generation of the first information.

[0144] S701, the first terminal sends a service request message to the access network element. Correspondingly, the access network element receives the service request message from the first terminal.

[0145] Specifically, when the first information is control signaling or service data for a first service, or when the service to be accessed by the first terminal is a first service in a first network, the service request message is used to request access to the service in the first network; when the first information is control signaling or service data for a second service, or when the service to be accessed by the first terminal is a service in a second network, the service request message is used to request access to the service in the second network. This embodiment of the application uses the example of the service request message being used to request access to a service in the second network for illustration.

[0146] As one possible implementation, the service request message may include a network identifier to indicate which network's service is being requested. For example, the first network and the second network may provide different services. The first terminal may pre-obtain the services provided by the first network and the services provided by the second network; for instance, the terminal may maintain a mapping relationship between the aforementioned services and networks. Therefore, the first terminal can first determine whether the service associated with the control signaling / service data to be sent is a service in the first network or a service in the second network, and then send a service request message carrying the corresponding network identifier in the service request message.

[0147] As one possible implementation, the service request message may include a service identifier, which is the identifier of a service in the second network that the first terminal requests to access. In this application, taking the first terminal requesting access to a second service in the second network as an example, the service request message may include the identifier of the second service.

[0148] For example, the first network and the second network may provide different services; therefore, the corresponding network can be indicated by a service identifier. For instance, if the second network provides a second service, then the service request message carrying the identifier of the second service can indicate the second network.

[0149] As one possible implementation, the service request message may include a task identifier. In this embodiment, a service may include at least one task; for example, service 1 may include task 1, task 2, task 3, etc. The first network and the second network may be used to implement different tasks of the same service, or to implement different tasks of different services. In this scenario, if the second service requested by the first terminal includes multiple tasks, the service request message may further include an identifier of at least one task in the second service to identify the task associated with this service request.

[0150] For example, since the first network and the second network can be used to implement different tasks, the corresponding network can also be indicated by the task identifier. For instance, if the second network provides the second task of the second service and the first network provides the first task of the first service, then carrying the identifier of the second task in the service request message can indicate the second network.

[0151] As one possible implementation, the first network and the second network can each assign different terminal identifiers / IP addresses to the first terminal. In this scenario, the service request message can include the terminal identifier / IP address of the first terminal, indicating the corresponding network through the terminal identifier / IP address of the first terminal.

[0152] For example, the first network assigns terminal identifier 1 / IP address 1 to the first terminal (which can be understood as the terminal identifier / IP address of the first terminal in the first network), and the second network assigns terminal identifier 2 / IP address 2 to the first terminal (which can be understood as the terminal identifier / IP address of the first terminal in the second network). The first terminal can first determine whether the requested service is a service in the first network or a service in the second network, and then carry the corresponding terminal identifier / IP address in the service request message. For example, if the first terminal determines that it is requesting access to a service in the first network, then the service request message carries terminal identifier 1 / IP address 1; if the first terminal determines that it is requesting access to a service in the second network, then the service request message carries terminal identifier 2 / IP address 2.

[0153] In summary, when a service request message is used to request access to a service in a second network, the service request message may carry at least one of the following: the identifier of the second network, the identifier of the second service, the identifier of the second task, the terminal identifier of the first terminal in the second network (such as terminal identifier 2), or the IP address of the first terminal in the second network.

[0154] S702. The access network element sends a service request message to the first control plane element. Correspondingly, the first control plane element receives the service request message from the access network element.

[0155] The first control plane network element is deployed in the first network, and can be referred to the relevant description in the system shown in Figure 3, which will not be repeated here.

[0156] The payload of this service request message is the same as that of the service request message in step S701 above. That is, it can be assumed that the access network element forwards (or transparently transmits) the service request message to the first control plane network element.

[0157] As one possible implementation, the access network element encapsulates the service request message received in step S701 to obtain message a, and sends message a to the first control plane network element. In the outer IP address of message a, the source IP address is the IP address of the access network element, the destination IP address is the IP address of the first control plane network element, and the destination port number is the port number of the first control plane network element. For example, the outer IP address is used for routing.

[0158] S703. The first control plane network element obtains the routing information of the second control plane network element and the routing information of the second user plane network element according to the service request message.

[0159] The second control plane network element and the second user plane network element are deployed in the second network. Please refer to the relevant description in the system shown in Figure 3. They will not be repeated here.

[0160] As one possible implementation, the routing information of the second control plane network element is used for signaling routing (or transmission), and the routing information of the second control plane network element is used to route signaling to the second control plane network element; the routing information of the second user plane network element is used for data routing (or transmission), and the routing information of the second user plane network element is used to route data to the second user plane network element.

[0161] As one possible implementation, the routing information of the second control plane network element may include at least one of the following: the IP address and / or port number associated with the second control plane network element, the identifier of the second control plane network element, the identifier of the connection between the second control plane network element and other network elements, or the IP address of the first terminal in the second network. The routing information of the second user plane network element is similar to that of the second control plane network element and will be described in detail in subsequent embodiments, and will not be repeated here.

[0162] As one possible implementation, the first control plane network element can also obtain routing information from the first control plane network element and the first user plane network element. The routing information of the first control plane network element may include at least one of the following: the IP address and / or port number associated with the first control plane network element, the identifier of the first control plane network element, the identifier of the connection between the first control plane network element and other network elements, or the IP address of the first terminal in the first network. The routing information of the first user plane network element is similar to that of the first control plane network element and will not be described in detail.

[0163] As one possible implementation, the first control plane network element obtains the routing information of the second control plane network element and the second user plane network element based on the service request message. This can be understood as: the first control plane network element obtains the routing information of the second control plane network element and the second user plane network element based on the triggering of the service request message.

[0164] In one possible implementation, the routing information of the second control plane network element or the second control plane network element can be at the terminal granularity, or at the service granularity, or at the task granularity.

[0165] As one possible implementation, when the second control plane network element is at the terminal level, different terminals may correspond to different second control plane network elements. That is, different second control plane network elements serve different terminals, or in other words, the terminals served by different second control plane network elements at the same time do not overlap. For example, the correspondence between terminals and second control plane network elements can be shown in Table 1 below.

[0166] Table 1

[0167] Referring to Table 1, terminals 1 and 2 correspond to the same second control plane network element, and their routing information is also the same. Therefore, signaling related to the second network for both terminals 1 and 2 can be routed to second control plane network element 1. Terminals 1 and 3 correspond to different second control plane network elements, resulting in different routing information for their respective second control plane network elements. Consequently, their signaling related to the second network will be routed to different second control plane network elements. For example, if the first terminal is terminal 1, the first control plane network element returns routing information 1 for second control plane network element 1; if the first terminal is terminal 3, the first control plane network element returns routing information 2 for second control plane network element 2.

[0168] As one possible implementation, when the second control plane network elements are granular at the service level, different services may correspond to different second control plane network elements. That is, different second control plane network elements serve different services, or the services served by different second control plane network elements at the same time do not overlap. For example, the correspondence between services and second control plane network elements can be shown in Table 2 below.

[0169] Table 2

[0170] Referring to Table 2, services a and b correspond to the same second control plane network element, and their corresponding routing information is also the same. Signaling related to services a and b can be routed to second control plane network element 1. Services a and c correspond to different second control plane network elements, so their routing information for the corresponding second control plane network elements is also different, and signaling related to them will be routed to different second control plane network elements.

[0171] As one possible implementation, when the second control plane network element is at the task level, different tasks correspond to different second control plane network elements, that is, different second control plane network elements serve different tasks. For details, please refer to the relevant explanations when the second control plane network element is at the service level, which will not be repeated here.

[0172] Similarly, the routing information of the second user plane network element or the second user plane network element can also be at the terminal granularity, or at the service granularity, or at the task granularity. Please refer to the relevant description of the second control plane network element above, which will not be repeated here.

[0173] Similarly, the first control plane network element or its routing information, and the first user plane network element or its routing information, can be at the terminal level, or at the service level, or at the task level.

[0174] In other words, the first control plane network element can obtain a routing mapping table at the terminal level (denoted as the first routing mapping table), or a routing mapping table at the service level (denoted as the second routing mapping table), or a routing mapping table at the task level (denoted as the third routing mapping table). Based on the above three types of routing mapping tables, the terminal's signaling / data can be routed to the corresponding network according to the terminal's identifier in different networks, the different services provided by different networks, or the tasks that different networks can perform.

[0175] For example, the first route mapping table can take the form shown in Table 3 below. The second route mapping table can take the form shown in Table 4 below.

[0176] Table 3

[0177] Terminal identifier 11 and terminal identifier 12 are respectively the terminal identifiers of terminal 1 in the first network and the second network. The meanings of the remaining terminal identifiers are similar and will not be elaborated further. The first control plane network element 1 and / or the first user plane network element 1 in the first network serve terminal 1 and terminal 2, and the second control plane network element 1 and / or the second user plane network element 1 in the second network serve terminal 1 and terminal 2. Signaling / data related to the first network of terminal 1 can be transmitted to the first control plane network element 1 and / or the first user plane network element 1 in the first network based on routing information 11; signaling / data related to the second network of terminal 1 can be transmitted to the second control plane network element 1 and / or the second user plane network element 1 in the second network based on routing information 12.

[0178] Table 4

[0179] The first network provides services 1, 2, and 3. Specifically, the first control plane network element 1 and / or the first user plane network element 1 in the first network serve services 1 and 2, and the first control plane network element 2 and / or the first user plane network element 2 serve services 3. The second network provides services 4, 5, and 6. Specifically, the second control plane network element 1 and / or the second user plane network element 1 serve services 4, and the second control plane network element 2 and / or the second user plane network element 2 serve services 5 and 6.

[0180] When the terminal requests access to service 1 or service 2, the signaling / data associated with service 1 or service 2 can be transmitted to the first control plane network element 1 and / or the first user plane network element 1 in the first network based on routing information a; when the terminal requests access to service 4, the signaling / data associated with service 4 can be transmitted to the second control plane network element 1 and / or the second user plane network element 1 in the second network based on routing information c.

[0181] As one possible implementation, the routing information mentioned above can be at the terminal level, or at the service level, or at the task level, or a combination of multiple levels of granularity, without limitation.

[0182] S704. The first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0183] The routing information of the second control plane network element can be used to determine the routing information of signaling to be routed to the second control plane network element. The routing information of the second user plane network element can be used to determine the routing information of data to be routed to the second user plane network element.

[0184] Optionally, the first control plane network element may also send information about the second control plane network element and the second user plane network element, such as identifiers and / or IP addresses, to the access network network element.

[0185] Optionally, the first control plane network element may also send the identifier of the second network to the access network element to instruct the routing information of the second control plane network element and the second user plane network element to be used for routing signaling and data related to the second network.

[0186] Optionally, the first control plane network element can also send the identifiers of the terminal / service / task corresponding to the second control plane network element and the second user plane network element to the access network element, so that the access network element can subsequently route the signaling / data of different terminals / services / tasks.

[0187] Optionally, the first control plane network element can also send routing information of the first control plane network element and routing information of the first user plane network element to the access network element. Furthermore, it can also send the identifier of the first network, the identifier of the terminal / service / task corresponding to the second control plane network element and the second user plane network element, etc.

[0188] Optionally, after step S704, the access network element may send a service response message to the first terminal. Correspondingly, the first terminal receives the service response message from the access network element. The service response message indicates whether the service request was successful or failed, or indicates whether the network accepts or rejects the service request, or indicates whether access to services in the second network is permitted or not. In this embodiment, the example is a service response message indicating a successful service request or network acceptance of the service request, or indicating permission to access services in the second network.

[0189] Optionally, the service response message may also include routing information of the second control plane network element and routing information of the second user plane network element.

[0190] S705, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0191] The network indication information is used to indicate whether the first information is information from a first network or information from a second network. For example, whether the first information is information from a first network or information from a second network can be understood as: the destination of the first information is the first network or the second network, or the first information is to be sent (or needs to be sent) to the first network or the second network. These three descriptions can be used interchangeably, and are uniformly described here. Subsequent embodiments will not repeat them.

[0192] As one possible implementation, the network indication information may include the identifier of a network, such as the identifier of a first network or the identifier of a second network, wherein the identifier of the first network indicates that the first information is information of the first network, and the identifier of the second network indicates that the first information is information of the second network.

[0193] As another possible implementation, the network indication information may include the terminal identifier / IP address of the first terminal, for example, including the terminal identifier / IP address of the first terminal in a first network, indicating that the first information is information of the first network; or including the terminal identifier / IP address of the first terminal in a second network, indicating that the first information is information of the second network. Furthermore, the terminal identifier / IP address of the first terminal may also indicate that the first information is terminal-level information.

[0194] As another possible implementation, the network indication information may include a service identifier. If the service is in a first network, the first information indicates that it is information of the first network; if the service is in a second network, the first information indicates that it is information of the second network. Furthermore, the service identifier may also indicate that the first information is service-level information.

[0195] As another possible implementation, the network indication information may include a task identifier. If the task is implemented by a first network, the first information indicates that it is information of the first network; if the task is implemented by a second network, the first information indicates that it is information of the second network. Furthermore, the task identifier may also indicate that the first information is task-level information.

[0196] As another possible implementation, the network indication information may include routing information (such as identifier and / or IP address) of the destination network element, which is the recipient of the first information. For example, when the first information is information of a first network, the network indication information may include routing information of a first control plane network element or a first user plane network element; when the first information is information of a second network, the network indication information may include routing information of a second control plane network element or a second user plane network element. For instance, the routing information of the destination network element may be returned by the network to the first terminal.

[0197] Based on the above implementation, when the first information is information of the second network, or when the first information is to be sent to the second network, the network indication information may include at least one of the following: the identifier of the second network, the terminal identifier of the first terminal in the second network, the IP address of the first terminal in the second network, the identifier of the second service, the identifier of the second task, the routing information of the second control plane network element, or the routing information of the second user plane network element.

[0198] As one possible implementation, the first information can be either signaling or data. For ease of description, when the first information is signaling, it can be referred to as the first signaling, and when the first information is data, it can be referred to as the first data.

[0199] Wherein, if the first information is a first signaling and the network indication information indicates that the first information is information of the second network, the method further includes the following steps S706a-S707a; if the first information is first data and the network indication information indicates that the first information is information of the second network, the method further includes the following steps S706b-S707b.

[0200] S706a. The access network element sends a first signaling message and its routing information to a first control plane network element or a first user plane network element. The routing information for the first signaling message is used to route the first signaling message to a second control plane network element.

[0201] For example, in the first scenario described above, the access network element sends the first signaling and the routing information of the first signaling to the first control plane network element; in the second scenario described above, the access network element sends the first signaling and the routing information of the first signaling to the first user plane network element.

[0202] In one possible implementation, the access network element can look up the routing information of the second control plane network element based on the network indication information, and determine the routing information of the first signaling based on the routing information of the second control plane network element.

[0203] As one possible implementation, when the network indication information includes the terminal identifier of the first terminal in the second network, the access network element can look up the routing information of the second control plane network element in the first routing mapping table. This first routing mapping table includes the mapping relationship between the terminal identifier of the first terminal in the second network and the routing information of the second control plane network element. For example, taking the first routing mapping table as shown in Table 3, where the identifier of the first terminal in the second network is terminal identifier 12, then the second control plane network element is second control plane network element 1, and the routing information of the second control plane network element is the identifier of second control plane network element 1 included in the routing information 12.

[0204] As one possible implementation, when the network indication information includes the identifier of the second service, the access network element can look up the routing information of the second control plane network element in the second routing mapping table. This second routing mapping table includes the mapping relationship between the identifier of the second service and the routing information of the second control plane network element. For example, if the second routing mapping table is shown in Table 4, and the second service is service 4, then the second control plane network element is second control plane network element 1, and the routing information of the second control plane network element is the identifier of the second control plane network element included in the routing information c.

[0205] As one possible implementation, if the network indication information includes the identifier of the second task, the access network element can look up the routing information of the second control plane network element corresponding to the identifier of the task in the third routing mapping table.

[0206] In another possible implementation, if the network indication information includes routing information of the second control plane network, the access network element can determine the routing information of the first signaling based on the routing information of the second control plane network element included in the network indication information.

[0207] S707a, the first control plane network element or the first user plane network element sends the first signaling to the second control plane network element.

[0208] As one possible implementation, before step S707a, the first control plane network element or the first user plane network element can determine whether to send the first signaling to the second control plane network element based on the routing information of the first signaling. For example, if the routing information of the first signaling matches the routing information of the second control plane network element, the first control plane network element or the first user plane network element determines whether to send the first signaling to the second control plane network element. The implementation of matching the routing information of the first signaling with the routing information of the second control plane network element will be described in detail in subsequent embodiments and will not be repeated here.

[0209] S706b: The access network element sends first data and routing information for the first data to the first user plane network element. The routing information for the first data is used to route the first data to the second user plane network element.

[0210] For example, in either scenario one or scenario two described above, the access network element sends first data and routing information for the first data to the first user plane network element. In one possible implementation, the access network element can look up the routing information of the second user plane network element based on the network indication information, and determine the routing information for the first data based on the routing information of the second user plane network element; or, if the network indication information includes the routing information of the second user plane network element, the access network element can determine the routing information for the first signaling based on the routing information of the second user plane network element included in the network indication information. Refer to the relevant description in step S706a above; it will not be repeated here.

[0211] S707b: The first user plane network element root sends the first data to the second user plane network element.

[0212] As one possible implementation, before step S707b, the first user plane network element can determine whether to send the first data to the second user plane network element based on the routing information of the first data. For example, if the routing information of the first data matches the routing information of the second user plane network element, the first user plane network element determines to send the first data to the second user plane network element. The implementation of matching the routing information of the first data with the routing information of the second user plane network element will be described in detail in subsequent embodiments and will not be repeated here.

[0213] Based on the above scheme, the first control plane network element in the first network can obtain the routing information of the second control plane network element and the second user plane network element in the second network, and return the routing information of the second control plane network element and the second user plane network element to the access network element. This enables the access network element to send a message to the first control plane network element / first user plane network element in the first network when it needs to send signaling / data to the second network. The message carries the routing information of the second control plane network element / second user plane network element, so that the first control plane network element / first user plane network element can forward the signaling / data to be sent to the second network to the second control plane network element / second user plane network element according to the routing information. This realizes the communication between the access network element and the network elements in the second network, thereby supporting various user needs for the subnet, such as supporting increasingly higher mobility requirements for the subnet and improving the user experience.

[0214] The overall process of the communication method provided in this application has been described above. The following is a detailed explanation of the various implementations of routing information and the corresponding communication processes in the above communication method under either scenario one or scenario two.

[0215] In a first possible implementation scenario, as described in Scenario 1 above, where the routing information of the second control plane network element is the port number associated with the second control plane network element, and the routing information of the second user plane network element is the port number associated with the second user plane network element, the communication process provided in this application can be as shown in Figure 8. Referring to Figure 8, this communication process may include the following steps:

[0216] S801. The first terminal sends a service request message to the access network element. Correspondingly, the access network element receives the service request message from the first terminal.

[0217] This service request message is used to request access to services in the second network. Refer to the relevant explanation of step S701 above; it will not be repeated here.

[0218] S802. The access network element sends a service request message to the first control plane network element. Correspondingly, the first control plane network element receives the service request message from the access network element. Refer to the relevant explanation of step S702 above; it will not be repeated here.

[0219] S803. The first control plane network element selects the second control plane network element based on the service request message.

[0220] As one possible implementation, since the service request message is used to request access to services in the second network, the first control plane element can select a control plane element in the second network as the second control plane element.

[0221] For example, taking the second network as a subnet, assuming there are multiple subnets, the first control plane network element obtains information about these multiple subnets. If a service request message is used to request access to a service in subnet 1, the first control plane network element can select a control plane network element in subnet 1 as the second control plane network element.

[0222] Optionally, if there are multiple control plane network elements in the second network, the first control plane network element can select the second control plane network element from the multiple control plane network elements according to the capabilities, load, etc. of each control plane network element.

[0223] For example, if the service request message includes the identifier of the second service, the first control plane can select a control plane network element in the second network that serves (or provides) the second service as the second control plane network element.

[0224] Furthermore, if the service request message includes an identifier for the second task, the first control plane network element can select a control plane network element in the second network associated with the second task as the second control plane network element. For example, the second control plane network element is used to implement or is capable of completing the second task.

[0225] As one possible implementation, the second control plane network element can be at the terminal level, or at the service level, or at the task level. Correspondingly, the routing information of the second control plane network element is also at the terminal level, or at the service level, or at the task level. Please refer to the relevant description in step S703 above, which will not be repeated here.

[0226] S804. The first control plane network element allocates routing information of the second control plane network element to the second control plane network element.

[0227] In this context, the routing information for the second control plane network element is its port number. That is, step S804 can also be understood as: the first control plane network element assigning a port number to the second control plane network element.

[0228] In this case, the port number of the second control plane network element is different from the port number of the first control plane network element. For example, the port number of the first control plane network element is port1, and the port number of the second control plane network element is port2.

[0229] As one possible implementation, the first control plane network element establishes a network address translation (NAT) mapping relationship between its IP address and the port number of the second control plane network element (denoted as the first NAT mapping relationship). For example, taking the first control plane network element as MM1, the second control plane network element as MM2, and the port number assigned to the second control plane network element as port2, this first NAT mapping relationship can be represented as MM1's IP address + port2 -> MM2's IP address.

[0230] As one possible implementation, for different terminals, different services, or different tasks corresponding to the same second control plane network element, the first control plane network element can allocate different ports to the second control plane network element. For example, taking the case where both terminal 1 and terminal 2 correspond to the second control plane network element 1, if the first terminal is terminal 1, then in step S804, the first control plane network element allocates port 21 to the second control plane network element 1; if the first terminal is terminal 2, then in step S804, the first control plane network element allocates port 22 to the second control plane network element 1.

[0231] Optionally, the first control plane network element may also establish a NAT mapping relationship between the IP address of the first control plane network element, the port number of the first control plane network element, and the IP address of the first control plane network element (denoted as the second NAT mapping relationship).

[0232] For example, the first NAT mapping relationship is used by the first control plane network element to forward signaling of the second network to the second control plane network element, and the second NAT mapping relationship is used by the first control plane network element to process the signaling of the first network locally. This will be described in subsequent embodiments and will not be repeated here.

[0233] S805. The first control plane network element sends a service request message to the second control plane network element. Correspondingly, the second control plane network element receives the service request message from the first control plane network element.

[0234] The payload of this service request message is the same as that of the service request message in step S802 above. That is, it can be considered that the first control plane network element forwards (or transparently transmits) the service request message to the second control plane network element.

[0235] S806. The second control plane network element selects the second user plane network element based on the service request message.

[0236] The second user plane network element is deployed in the second network. Please refer to the relevant description in the system shown in Figure 3 above, which will not be repeated here.

[0237] As one possible implementation, if there are multiple user plane network elements in the second network, the second control plane network element can select the second user plane network element from the multiple user plane network elements based on the capabilities, load, etc. of each user plane network element.

[0238] As one possible implementation, if the service request message includes the identifier of the second service, the second control plane network element can select a user plane network element in the second network that provides (or serves) the second service as the second user plane network element.

[0239] Furthermore, if the service request message includes an identifier for the second task, the second control plane network element can select a user plane network element associated with the second task in the second network as the second user plane network element. For example, the second user plane network element is used to implement or is capable of completing the second task.

[0240] As one possible implementation, the second user plane network element can be terminal-level, service-level, or task-level. Correspondingly, the routing information of the second user plane network element is also terminal-level, service-level, or task-level. Please refer to the relevant description in step S703 above, which will not be repeated here.

[0241] S807. The second control plane network element sends a service request message to the second user plane network element. Correspondingly, the second user plane network element receives the service request message from the second control plane network element. The payload of this service request message is the same as the payload of the service request message in step S802 above, as explained in the relevant description above, and will not be repeated here.

[0242] S808, the second user plane network element sends a service response message to the second control plane network element. Correspondingly, the second control plane network element receives the service response message from the second user plane network element.

[0243] As one possible implementation, the service response message can indicate whether the service request was successful or failed, or instruct the second user plane network element to accept or reject the service request, or indicate whether access to services in the second network is permitted or not. This embodiment of the application uses the indication of a successful or accepted service request, or the indication of permitted access to services in the second network, as an example for illustration.

[0244] As one possible implementation, the service response message may include the IP address and / or identifier of the second user plane network element. The IP address returned by the second user plane network element can be understood as the IP address used by the second user plane network element when transmitting data. The IP address used by the second user plane network element when transmitting data (denoted as the first IP address of the second user plane network element) may be different from or the same as the IP address used by the second user plane network element when communicating with the second control plane network element (denoted as the second IP address of the second user plane network element).

[0245] It should be noted that if the first IP address of the second user plane network element is the same as the second IP address of the second user plane network element, step S808 may not include the first IP address of the second user plane network element, and the second control plane network element will use the second IP address of the second user plane network element as the first IP address of the second user plane network element.

[0246] For example, when the service response message includes the identifier of the second user plane network element, the second control plane network element can obtain the first IP address of the second user plane network element based on the mapping relationship between the identifier and IP address. This mapping relationship between the identifier and IP address can be pre-configured within the second control plane network element, such as through the operation administration and maintenance (OAM) network element, or it can be obtained by the second control plane network element by querying other network elements; there are no restrictions.

[0247] S809. The second control plane network element sends the IP address of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the IP address of the second user plane network element from the second control plane network element.

[0248] S810, the first control plane network element sends a first request message to the first user plane network element. Correspondingly, the first user plane network element receives the first request message from the first control plane network element.

[0249] The first request information is used to request routing information from the second user plane network element. The first user plane network element is deployed in the first network, and can be referred to the relevant description in the system shown in Figure 3, which will not be repeated here.

[0250] As one possible implementation, the first request information may include the IP address of the second user plane network element. After receiving the first request information, the first user plane network element can allocate routing information to the second user plane network element. The routing information for the second user plane network element is its port number.

[0251] In this case, the port number of the second user plane network element is different from the port number of the first user plane network element. For example, the port number of the first user plane network element is port1', and the port number of the second control plane network element is port2'.

[0252] As one possible implementation, the first user plane network element establishes a NAT mapping relationship between its IP address and the port number of the second user plane network element (denoted as the third NAT mapping relationship). For example, taking the first user plane network element as UPF1, the second user plane network element as UPF2, and the port number assigned to the second user plane network element as port2', this third NAT mapping relationship can be represented as UPF1's IP address + port2' -> UPF2's IP address.

[0253] As one possible implementation, for different terminals, different services, or different tasks corresponding to the same second user plane network element, the first user plane network element can allocate different ports to the second user plane network element. Refer to the relevant explanation in step S804 above regarding the allocation of different ports by the first control plane network element to the same second control plane network element; it will not be repeated here.

[0254] Optionally, the first user plane network element also establishes a NAT mapping relationship between the IP address of the first user plane network element, the port number of the first user plane network element, and the IP address of the first user plane network element (referred to as the fourth NAT mapping relationship).

[0255] For example, the third NAT mapping relationship is used for the first user plane network element to forward data from the second network to the second user plane network element, and the fourth NAT mapping relationship is used for the first user plane network element to process data from the first network locally. These will be described in subsequent embodiments and will not be repeated here.

[0256] S811, the first user plane network element sends the routing information of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the routing information of the second user plane network element from the first user plane network element.

[0257] For example, the first user plane network element can send a third NAT mapping relationship to the first control plane network element, which includes the routing information of the second user plane network element.

[0258] Optionally, the first user plane network element can also send a fourth NAT mapping relationship to the first control plane network element.

[0259] As one possible implementation, steps S804 and S810-S811 above can be understood as an implementation of the first control plane network element obtaining routing information from the second control plane network element and the second user plane network element.

[0260] S812, the first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0261] As one possible implementation, the first control plane network element sends the mapping relationship between the IP address of the first control plane network element and the routing information of the second control plane network element to the access network element, such as sending the IP address of MM1 + port2; and sends the mapping relationship between the IP address of the first user plane network element and the routing information of the second user plane network element, such as sending the IP address of UPF1 + port2'.

[0262] As another possible implementation, the first control plane network element can send a first NAT mapping relationship and a third NAT mapping relationship to the access network element. The first NAT mapping relationship carries the routing information of the second control plane network element and the IP address of the first control plane network element, and the third NAT mapping relationship carries the routing information of the second user plane network element and the IP address of the first user plane network element.

[0263] Optionally, the first control plane network element may also send to the access network element at least one of the following: information about the second control plane network element, information about the second user plane network element, the identifier of the second network, and the identifiers of the terminal / service / task corresponding to the second control plane network element and the second user plane network element. Refer to the relevant description in step S704 above; it will not be repeated here.

[0264] As one possible implementation, the first control plane network element can also send the mapping relationship between the IP address of the first control plane network element and the routing information of the first control plane network element to the access network element, such as sending the IP address of MM1 + port1; and send the mapping relationship between the IP address of the first user plane network element and the routing information of the first user plane network element, such as sending the IP address of UPF1 + port1'.

[0265] As another possible implementation, the first control plane network element can also send the second NAT mapping relationship and the fourth NAT mapping relationship to the access network element.

[0266] Optionally, after step S812, the access network element may also send a service response message to the first terminal. Refer to the foregoing explanation of the service response message; further details will not be repeated here.

[0267] In one possible implementation, a first connection is established between the first control plane network element and the second control plane network element, and a second connection is established between the first user plane network element and the second user plane network element. A third connection is established between the access network element and the first control plane network element, and a fourth connection is established between the access network element and the first user plane network element.

[0268] As one possible implementation, the first connection may be established before the first control plane network element allocates routing information to the second control plane network element, or after the first control plane network element allocates routing information to the second control plane network element, or before or after the first control plane network element sends routing information of the second control plane network element to the access network element, or during the process of the first control plane network element sending routing information of the second control plane network element to the access network element. This application does not specifically limit the order in which routing information of the second control plane network element is allocated / sent and the first connection is established; there is no dependency between the two, and they can be decoupled and executed independently.

[0269] For example, the first connection can be at the terminal level, the service level, or the task level. For instance, the first control plane network element and the second control plane network element can establish different first connections for different terminals, different first connections for different services of the same terminal, or different first connections for different tasks of the same service of the same terminal.

[0270] For example, the identifier of the first connection can be a single identifier, such as connection identifier 1; or, the identifier of the first connection can include two parts, such as first identifier 1 and first identifier 2. First identifier 1 can be an identifier assigned by a first control plane network element for identifying the first terminal on the first control plane network element side; first identifier 2 can be an identifier assigned by a second control plane network element for identifying the first terminal on the second control plane network element side. Furthermore, when the identifier of the first connection includes first identifier 1 and first identifier 2, the first control plane network element can send first identifier 1 to the second control plane network element, and the second control plane network element can send first identifier 2 to the first control plane network element.

[0271] As one possible implementation, the order of establishing the second connection and allocating / sending routing information for the second user plane network element is not specifically limited, and there is no dependency between the two. They can be decoupled and executed independently. Refer to the relevant descriptions of the first connection and the allocation / sending of routing information for the second control plane network element. They will not be repeated here.

[0272] For example, the second connection can be at the terminal level, the business level, or the task level. Refer to the relevant description of the first connection; it will not be repeated here.

[0273] For example, the identifier of the second connection can be a single, unified identifier, such as connection identifier 2; or, the identifier of the second connection can include a second identifier 1 and a second identifier 2. The second identifier 1 can be assigned to a first user plane network element to identify the endpoint of the second connection on the first user plane network element side; the second identifier 2 can be assigned to a second user plane network element to identify the endpoint of the second connection on the second user plane network element side. Therefore, the second identifier 1 and the second identifier 2 can also be referred to as connection endpoint identifiers. The second identifier 1 and the second identifier 2 can be associated with the first terminal.

[0274] As one possible implementation, the third connection can be carried by a next-generation application protocol (NGAP). The identifier for the third connection can be a single, unified identifier, such as connection identifier 3; or the identifier can include the RAN UE NGAP ID and the AM / MM / SM UE NGAP ID. The RAN UE NGAP ID is an identifier assigned by the access network element for identifying the first terminal on the access network side, and the AM / MM / SM UE NGAP ID is an identifier assigned by the first control plane network element for identifying the first terminal on the first control plane network element side. For example, the third connection can be established when the first terminal initially accesses the network, or it can be established at other times; this application does not specifically limit the timing of the establishment of the third connection.

[0275] As one possible implementation, the fourth connection can be a General Packet Radio Service (GPRS) tunneling protocol (GTP) tunnel. The identifier for the fourth connection can be a single identifier, such as connection identifier 4 or tunnel identifier; alternatively, the identifier for the fourth connection can include tunnel end point identifier (TEID) 1 and TEID 2. TEID 1 can be assigned by an access network element to identify the endpoint of the fourth connection on the access network element side, and TEID 2 can be assigned by a first user plane network element to identify the endpoint of the fourth connection on the first user plane network element side. For example, the fourth connection can be established before the first terminal performs data transmission, or it can be established at other times; this application does not specifically limit the establishment timing of the third and fourth connections.

[0276] Steps S801-S812 described above can be understood as the initial establishment or initial configuration phase. After step S812, signaling / data transmission of the second network can proceed. For example, after step S812, the method further includes the following steps:

[0277] S813, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0278] The network indication information is used to indicate whether the first information is from a first network or a second network. The first information is signaling or data. Refer to the relevant explanation in step S705 above.

[0279] As one possible implementation, after receiving the first information and the network indication information, the access network element can determine whether the first information is from the first network or the second network based on the network indication information. Furthermore, the access network element can identify whether the first information is signaling or data, and thus can look up the routing information of the second control plane network element or the second user plane network element from the routing mapping table based on the network indication information. Refer to the relevant explanation in step S706a above; it will not be repeated here.

[0280] Specifically, if the first information is a first signaling message and the network indication information indicates that the first information is information of the second network, then steps S814a-S815a are executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then steps S814b-S815b are executed; if the first information is a first signaling message and the network indication information indicates that the first information is information of the first network, then step S814c is executed; and if the first information is first data and the network indication information indicates that the first information is information of the second network, then step S814d is executed.

[0281] S814a, The access network element sends a first message to the first control plane element. Correspondingly, the first control plane element receives the first message from the access network element.

[0282] The first message includes a first signaling message and routing information for the first signaling message. The routing information for the first signaling message is used to route the first signaling message to the second control plane network element.

[0283] As one possible implementation, the routing information of the first signaling is determined based on the routing information of the second control plane network element. For example, if the routing information of the second control plane network element is its port number, the routing information of the first signaling indicates that the destination port number of the first signaling / first message is the port number of the second control plane network element. For instance, the destination port number field in the first message can be filled with the port number of the second control plane network element (e.g., port2). Here, the destination port number of the first message can be understood as the routing information of the first signaling. Furthermore, the destination IP address in the first message is the IP address of the first control plane network element, which can be the IP address returned by the first control plane network element to the access network element in step S812.

[0284] As one possible implementation, the access network element sends the first message to the first control plane network element through a third connection. The first message may also include first indication information, which indicates that the first signaling is signaling associated with the first terminal. For example, the first indication information may include the inner IP address of the first terminal, the identifier of the first terminal within the third connection (such as the RAN UE NGAP ID), the subscription permanent identifier (SUPI) of the first terminal, the temporary mobile subscriber identity (TMSI), etc.

[0285] Optionally, if the first indication information includes the identifier of the first terminal within the third connection, the first indication information may further include the identifier of the access network element. Since the first control plane element can connect to multiple access network elements, the identifiers that different access network elements can use may be duplicated. For example, both access network element 1 and access network element 2 can assign identifiers 1-100 to the terminals they serve. In this case, the signaling associated terminals cannot be distinguished solely by identifiers 1-100, and it is necessary to further indicate the signaling associated terminals using the identifiers of the access network elements.

[0286] S815a: Based on the routing information of the first signaling, the first control plane network element determines to send the first signaling to the second control plane network element, and the first control plane network element sends a third message to the second control plane network element. Correspondingly, the second control plane network element receives the third message from the first control plane network element. The third message includes the first signaling.

[0287] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the routing information of the first signaling. For example, if the routing information of the first signaling matches the routing information of the first control plane network element, it determines to process the first signaling locally; if the routing information of the first signaling matches the routing information of the second control plane network element, it determines to send the first signaling to the second control plane network element.

[0288] For example, when the routing information of the second control plane network element is the port number of the second control plane network element, matching the routing information of the first signaling with the routing information of the second control plane network element may include: the routing information of the first signaling indicating that the destination port number of the first signaling is the port number of the second control plane network element. For example, when the first control plane network element receives a first message, it learns from the destination port of the first message (i.e., the port of the second control plane network element) that the first signaling needs to be further forwarded to the second control plane network element. That is, when the routing information of the first signaling indicates that the destination port number is the port number of the second control plane network element, it determines to send the first signaling to the second control plane network element.

[0289] As one possible implementation, sending a third message from the first control plane network element to the second control plane network element may include: sending the third message to the second control plane network element according to the first NAT mapping relationship. For example, the first control plane network element performs NAT translation according to the first NAT mapping relationship to obtain the third message, and then sends the third message to the second control plane network element. The third message includes first signaling, and the destination IP address of the third message is the IP address of the second control plane network element.

[0290] For example, the first control plane network element can look up the NAT mapping relationship (i.e., the first NAT mapping relationship) that includes the port of the second control plane network element based on the port of the second control plane network element, and use the IP address of the second control plane network element in the first NAT mapping relationship as the destination IP address of the third message. That is, the first control plane network element can re-enter the destination IP address of the first signaling as the IP address of the second control plane network element. In addition, it can also re-enter the destination port as the port of the second control plane network element. It should be noted that the port of the second control plane network element re-entered by the first control plane network element can be the same as or different from the port number of the routing information of the second control plane network element mentioned above, without restriction.

[0291] As one possible implementation, the first control plane network element sends the third message to the second control plane network element through the first connection. The third message may also include third indication information, which indicates that the first signaling is signaling associated with the first terminal. For example, the third indication information may include the inner IP address of the first terminal, the identifier of the third connection (such as first identifier 1, first identifier 2), the SUPI of the first terminal, TMSI, etc.

[0292] Optionally, if the third indication information includes the identifier of the third connection, the third indication information may also include the identifier of the access network element. Refer to the relevant explanation of the first indication information above; it will not be repeated here.

[0293] S814b: The access network element sends a second message to the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0294] The second message includes first data and routing information for the first data, the routing information of which is used to route the first data to the second user plane network element.

[0295] As one possible implementation, the routing information of the first data is determined based on the routing information of the second user plane network element. For example, if the routing information of the second user plane network element is its port number, the routing information of the first data indicates that the destination port number of the first data / second message is the port number of the second user plane network element. For instance, the destination port number field in the second message can be filled with the port number of the second user plane network element (e.g., port2'). Here, the destination port number of the second message can be understood as the routing information of the first data. Furthermore, the destination IP address in the second message is the IP address of the first user plane network element, which can be the IP address returned by the first control plane network element to the access network element in step S812.

[0296] As one possible implementation, the access network element sends the second message to the first user plane network element via a fourth connection. The second message may also include second indication information, which indicates that the first data is data associated with the first terminal. For example, the second indication information may include the inner IP address of the first terminal, the identifier of the fourth connection (such as TEID), the SUPI of the first terminal, TMSI, etc.

[0297] Optionally, if the second indication information includes the identifier of the fourth connection, the second indication information may also include the identifier of the access network element. Refer to the relevant explanation of the first indication information above; it will not be repeated here.

[0298] S815b: Based on the routing information of the first data, the first user plane network element determines to send the first data to the second user plane network element, and the first user plane network element sends a fourth message to the second user plane network element. Correspondingly, the second user plane network element receives the fourth message from the first user plane network element. The fourth message includes the first data.

[0299] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the routing information of the first data. For example, if the routing information of the first data matches the routing information of the first user plane network element, it determines to process the first data locally; if the routing information of the first data matches the routing information of the second user plane network element, it determines to send the first data to the second user plane network element.

[0300] For example, when the routing information of the second user plane network element is the port number of the second user plane network element, matching the routing information of the first data with the routing information of the second user plane network element can include: the routing information of the first data indicating that the destination port number of the first data is the port number of the second user plane network element. For instance, when the first user plane network element receives a second message, it learns from the destination port of the second message (i.e., the port number of the second user plane network element) that the first data needs to be further forwarded to the second user plane network element. In other words, when the routing information of the first data indicates that the destination port number is the port number of the second user plane network element, it is determined that the first data will be sent to the second user plane network element.

[0301] As one possible implementation, sending a fourth message from the first user plane network element to the second user plane network element may include: sending the fourth message to the second user plane network element according to a third NAT mapping relationship. For example, the first user plane network element performs NAT translation according to the third NAT mapping relationship to obtain the fourth message, and then sends the fourth message to the second user plane network element. The fourth message includes first data, and the destination IP address of the fourth message is the IP address of the second user plane network element.

[0302] For example, the first user plane network element can look up the NAT mapping relationship (i.e., the third NAT mapping relationship) that includes the port of the second user plane network element based on the port of the second user plane network element, and use the IP address of the second user plane network element in the third NAT mapping relationship as the destination IP address of the fourth message. That is, the first user plane network element can re-enter the destination IP address of the first data as the IP address of the second user plane network element, and in addition, it can also re-enter the destination port as the port of the second user plane network element. It should be noted that the port of the second user plane network element re-entered by the first user plane network element can be the same as or different from the port number of the routing information of the second user plane network element mentioned above, without restriction.

[0303] As one possible implementation, the first user plane network element sends the fourth message to the second user plane network element through the second connection. The fourth message may also include fourth indication information, which indicates that the first data is data associated with the first terminal. For example, the fourth indication information may include the inner IP address of the first terminal, the identifier of the second connection (such as second identifier 1, second identifier 2), the SUPI of the first terminal, TMSI, etc.

[0304] Optionally, if the fourth indication information includes the identifier of the second connection, the fourth indication information may also include the identifier of the access network element. Refer to the relevant explanation of the first indication information above; it will not be repeated here.

[0305] S814c, The access network element sends a first message to the first control plane network element based on the routing information of the first control plane network element. Correspondingly, the first control plane network element receives the first message from the access network element.

[0306] The first message includes a first signaling instruction and its routing information. The routing information indicates that the destination port number of the first signaling instruction / first message is the port number of the first control plane network element. Furthermore, the destination IP address of the first message is the IP address of the first control plane network element. Refer to the relevant explanation in step S814a above; it will not be repeated here.

[0307] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the destination port number. For example, if the destination port number of the first message is the port number of the first control plane network element, the first signaling is processed. Refer to the relevant description in step S815a above; it will not be repeated here.

[0308] S814d, The access network element sends a second message to the first user plane network element based on the routing information of the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0309] The second message includes the first data and its routing information. The routing information for the first data indicates that the destination port number of the first data / second message is the port number of the first user plane network element. Furthermore, the destination IP address of the second message is the IP address of the first user plane network element. Refer to the relevant explanation in step S814b above; it will not be repeated here.

[0310] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the destination port number. For example, if the destination port number of the second message is the port number of the first user plane network element, the first data is processed. Refer to the relevant description in step S815b above; it will not be repeated here.

[0311] In one possible implementation, the communication method shown in FIG8 further includes step S800 (not shown in the figure). The implementation of step S800 is the same as that of step S700, and can be referred to the relevant description of S700 above, which will not be repeated here.

[0312] Based on the above description, when the access network element receives the first information from the first terminal, and this first information is signaling, the access network element sends the first information to the first control plane network element. Further, when the first information is signaling for the first network, the access network element sets the destination port of the signaling to the port of the first control plane network element (e.g., port1); when the first information is signaling for the second network, the access network element sets the destination port of the signaling to the port of the second control plane network element (e.g., port2). The destination IP address of the first information is always the IP address of the first control plane network element.

[0313] When the first information is data, the access network element sends the first information to the first user plane network element. Further, when the first information is data from the first network, the access network element fills in the destination port of the data as the port of the first user plane network element (e.g., port1'); when the first information is data from the second network, the access network element fills in the destination port of the data as the port of the second user plane network element (e.g., port2'). The destination IP address of the first information is always the IP address of the first user plane network element.

[0314] Furthermore, in the presence of multiple second networks, the first control plane network element can assign different port numbers to control plane network elements in different second networks, and the first user plane network element can assign different port numbers to user plane network elements in different second networks. For example, the first network is connected to second network 1 and second network 2. Port 2 can be assigned to MM2 in second network 1, and port 2' can be assigned to UPF2 in second network 1; port 3 can be assigned to MM3 in second network 2, and port 3' can be assigned to UPF3 in second network 2.

[0315] The routing of uplink signaling / data has been explained above. For downlink signaling, the second control plane network element sends downlink signaling to the first control plane network element. The first control plane network element performs NAT translation based on the routing information of the second control plane network element and then sends the downlink signaling to the access network element. For example, the NAT translation performed by the first control plane network element may include: replacing the source IP address in the message carrying the downlink signaling with the IP address of the first control plane network element, and replacing the source port number in the message with the port number of the second control plane network element (e.g., port2). After receiving the message, the access network element can determine that the signaling carried in the message belongs to the second network based on the port number of the second control plane network element, and can subsequently forward the signaling to the first terminal and indicate that the signaling belongs to the second network. Note that the port number of the second control plane network element can be the same or different in both uplink and downlink signaling transmissions.

[0316] Alternatively, the second control plane network element sends downlink signaling to the first control plane network element. When the first control plane network element sends the downlink signaling to the access network element, it may carry indication information to indicate that the downlink signaling comes from the second control plane network element, or to indicate that the downlink signaling is signaling from the second network.

[0317] Furthermore, the messages carrying downlink signaling sent by the second control plane network element and the first control plane network element may also carry indication information to indicate the terminal associated with the signaling. The implementation of this indication information is similar to the first indication information in step S814a and the third indication information in step S815a, except that the identifier of the access network element in the indication information needs to be replaced with the identifier of the second control plane network element. For details, please refer to the relevant descriptions of the first indication information in step S814a and the third indication information in step S815a, which will not be repeated here.

[0318] Similarly, for downlink data, the second user plane network element sends downlink data to the first user plane network element. The first user plane network element performs NAT translation based on the routing information of the second user plane network element before sending the downlink data to the access network element. For example, the NAT translation performed by the first user plane network element may include: replacing the source IP address in the message carrying downlink signaling with the IP address of the first user plane network element, and replacing the destination IP address in the message with the port number of the second user plane network element (e.g., port2'). Upon receiving the message, the access network element can determine that the data carried in the message is signaling from the second network based on the port number of the second user plane network element, and subsequently forward the data to the first terminal, indicating that the data belongs to the second network. The port number of the second user plane network element can be the same or different in both uplink and downlink data transmission.

[0319] Alternatively, when the second user plane network element sends downlink data to the first user plane network element, and the first user plane network element sends the downlink data command to the access network element, it may carry indication information to indicate that the downlink data comes from the second user plane network element, or to indicate that the downlink data is data from the second network.

[0320] Furthermore, the messages carrying downlink data sent by the second data plane network element and the first data plane network element may also carry indication information to indicate the terminal associated with the data. The implementation of this indication information is similar to the second indication information in step S814b and the fourth indication information in step S815b above, except that the identifier of the access network element in the indication information needs to be replaced with the identifier of the second data plane network element. Please refer to the relevant descriptions above, which will not be repeated here.

[0321] The process shown in Figure 8 uses the routing information of the second control plane network element and the second user plane network element as an example to illustrate the concept. Furthermore, in one possible implementation, the routing information of the second control plane network element can be replaced with the IP address associated with the second control plane network element, and the routing information of the second user plane network element can be replaced with the IP address associated with the second user plane network element.

[0322] For example, in step S804 above, the first control plane network element can assign IP address 2 to the second control plane network element and IP address 1 to the first control plane network element. In subsequent step S814a, the destination IP address of the first message sent by the access network element can be filled in as IP address 2, and in step S814c, the destination IP address of the first message sent by the access network element can be filled in as IP address 1. The first control plane network element determines whether to process the signaling locally or forward the signaling to the second control plane network element based on the destination IP address in the message sent by the access network element. Similar to the implementation when the routing information is a port number, please refer to the relevant descriptions above, which will not be repeated here.

[0323] Meanwhile, in step S810 above, the first user plane network element can assign IP address 2' to the second user plane network element and IP address 1' to the first user plane network element. In subsequent step S814b, the destination IP address of the second message sent by the access network element can be filled in as IP address 2', and in step S814d, the destination IP address of the second message ' sent by the access network element can be filled in as IP address 1'. The first user plane network element determines whether to process the data locally or forward the data to the second user plane network element based on the destination IP address in the message sent by the access network element. Similar to the implementation when the routing information is a port number, please refer to the relevant explanations above, which will not be repeated here.

[0324] In another possible implementation, the routing information of the second control plane network element can be the IP address and port number associated with the second control plane network element. The routing information of the second user plane network element can be the IP address and port number associated with the second user plane network element. For example, in step S804, the first control plane network element can assign IP address 2 and port 2 to the second control plane network element, and assign IP address 1 and port 1 to the first control plane network element; in step S810 above, the first user plane network element assigns IP address 2' and port 2' to the second user plane network element, and assigns IP address 1' and port 1' to the first user plane network element. In this scenario, the signaling / data routing method can be a superposition of the implementation methods when the routing information is a port number or an IP address, which can be referred to the relevant descriptions above, and will not be repeated here.

[0325] In the above scheme, when the access network element sends signaling to the first control plane element, it distinguishes whether the signaling is intended for the first network or the second network using different ports and / or IP addresses. This allows the first control plane element to determine whether the signaling needs to be processed locally or forwarded based on the port and / or IP address. If forwarding is required, it can further perform corresponding routing based on the port and / or IP address. Furthermore, when the access network element sends data to the first user plane element, it distinguishes whether the data is intended for the first network or the second network using different ports and / or IP addresses. This allows the first user plane element to perform corresponding processing or routing based on the port and / or IP address. This enables signaling / data transmission between the access network element and the second network, supports the separation of the core network elements of the second network from the first network, and thus meets various user needs of the second network, such as meeting increasingly higher mobility requirements and improving user experience.

[0326] In a second possible implementation scenario, where, in scenario one above, the routing information of the second control plane network element is the identifier of the second control plane network element, and the routing information of the second user plane network element is the identifier of the second user plane network element, the communication process provided in this application can be as shown in Figure 9. Referring to Figure 9, this communication process may include the following steps:

[0327] S901-S903 are the same as steps S801-S803 above. Please refer to the relevant explanations of steps S801-S803 above. They will not be repeated here.

[0328] S904. The first control plane network element allocates routing information of the second control plane network element to the second control plane network element.

[0329] In this context, the routing information of the second control plane network element is the identifier of the second control plane network element. That is, step S904 can be understood as the first control plane network element assigning an identifier to the second control plane network element.

[0330] The identifiers of the first control plane network elements and the second control plane network elements are different. For example, the identifier of the first control plane network element is id 1, and the identifier of the second control plane network element is id 2.

[0331] As one possible implementation, the first control plane network element establishes a mapping relationship between its IP address and the identifier of the second control plane network element (denoted as the first identifier mapping relationship). For example, taking the first control plane network element as MM1, the second control plane network element as MM2, and the identifier assigned to the second control plane network element as id2, this first identifier mapping relationship can be represented as MM1's IP address + id2 -> MM2's IP address.

[0332] As one possible implementation, for different terminals, different services, or different tasks corresponding to the same second control plane network element, the first control plane network element can assign different identifiers to the second control plane network element. Refer to the relevant description in step S804; it will not be repeated here.

[0333] Optionally, the first control plane network element also establishes a mapping relationship between the IP address of the first control plane network element, the identifier of the first control plane network element, and the IP address of the first control plane network element (denoted as the second identifier mapping relationship).

[0334] For example, the first identifier mapping relationship is used for the first control plane network element to forward signaling of the second network to the second control plane network element, and the second identifier mapping relationship is used for the first control plane network element to process the signaling of the first network locally. This will be described in subsequent embodiments and will not be repeated here.

[0335] S905-S909 are the same as steps S805-S809 above, and can be referred to the relevant explanations in steps S805-S809 above, which will not be repeated here.

[0336] S910, the first control plane network element sends a first request message to the first user plane network element. Correspondingly, the first user plane network element receives the first request message from the first control plane network element.

[0337] The first request information is used to request routing information from the second user plane network element. For example, the first request information may include the IP address of the second user plane network element.

[0338] As one possible implementation, after receiving the first request information, the first user plane network element can allocate routing information to the second user plane network element. The routing information for the second user plane network element is its identifier. The identifier of the second user plane network element is different from the identifier of the first user plane network element. For example, the identifier of the first user plane network element is id 1', and the identifier of the second user plane network element is id 2'.

[0339] As one possible implementation, the first user plane network element establishes a mapping relationship between its IP address and the identifier of the second user plane network element (denoted as the third identifier mapping relationship). For example, taking the first user plane network element as UPF1, the second user plane network element as UPF2, and the identifier assigned to the second user plane network element as id 2', this mapping relationship can be represented as the IP address of UPF1 + id 2' -> the IP address of UPF2.

[0340] As one possible implementation, for different terminals, different services, or different tasks corresponding to the same second user plane network element, the first user plane network element can assign different identifiers to the second user plane network element.

[0341] Optionally, the first user plane network element also establishes a mapping relationship between the IP address of the first user plane network element, the identifier of the first user plane network element, and the IP address of the first user plane network element (denoted as the fourth identifier mapping relationship).

[0342] For example, the third identifier mapping relationship is used for the first user plane network element to forward data from the second network to the second user plane network element, and the fourth identifier mapping relationship is used for the first user plane network element to process data from the first network locally. These will be described in subsequent embodiments and will not be repeated here.

[0343] S911, the first user plane network element sends the routing information of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the routing information of the second user plane network element from the first user plane network element.

[0344] For example, the first user plane network element can send a third identifier mapping relationship to the first control plane network element, which includes the routing information of the second user plane network element.

[0345] Optionally, the first user plane network element may also send a fourth identifier mapping relationship to the first control plane network element.

[0346] In steps S910-S911 above, the example of a first user plane network element allocating routing information to a second user plane network element is used for illustration. In another possible implementation, the routing information of the second user plane network element can also be allocated by the first control plane network element. In this case, step S910 above can be replaced by: the first control plane network element allocating routing information to the second user plane network element, such as allocating the identifier of the second user plane network element. The implementation of the first control plane network element can refer to the implementation of the first user plane network element in step S910, and will not be repeated here. In addition, step S911 above can be replaced by: the first control plane network element sending the routing information of the second user plane network element to the first user plane network element, such as sending a third identifier mapping relationship and a fourth identifier mapping relationship (optional) to the first user plane network element.

[0347] As one possible implementation, steps S904 and S910-S911 above can be understood as an implementation of the first control plane network element obtaining routing information from the second control plane network element and the second user plane network element.

[0348] S912, the first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0349] Similar to step S812 above, the difference is that the routing information in step S912 is the identifier of the network element. Refer to the relevant description of step S812 above; it will not be repeated here.

[0350] Optionally, after step S912, the access network element may also send a service response message to the first terminal. Refer to the foregoing explanation of the service response message; further details will not be repeated here.

[0351] In one possible implementation, a first connection is established between the first control plane network element and the second control plane network element, and a second connection is established between the first user plane network element and the second user plane network element. A third connection is established between the access network element and the first control plane network element, and a fourth connection is established between the access network element and the first user plane network element. Refer to the relevant descriptions in the flowchart shown in Figure 8; they will not be repeated here.

[0352] Steps S901-S912 described above can be understood as the initial establishment or initial configuration phase. After step S912, signaling / data transmission of the second network can proceed. For example, after step S912, the method further includes the following steps:

[0353] S913, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0354] The network indication information is used to indicate whether the first information is from a first network or a second network. The first information is signaling or data. Refer to the relevant explanation in step S813 above.

[0355] As one possible implementation, after receiving the first information and the network indication information, the access network element can determine whether the first information is from the first network or the second network based on the network indication information. Furthermore, the access network element can identify whether the first information is signaling or data, and thus can look up the routing information of the second control plane network element or the second user plane network element from the routing mapping table based on the network indication information. Refer to the relevant explanation in step S706a above; it will not be repeated here.

[0356] Specifically, if the first information is a first signaling message and the network indication information indicates that the first information is information of the second network, then steps S914a-S915a are executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then steps S914b-S915b are executed; if the first information is a first signaling message and the network indication information indicates that the first information is information of the first network, then step S914c is executed; and if the first information is first data and the network indication information indicates that the first information is information of the second network, then step S914d is executed.

[0357] S914a, The access network element sends a first message to the first control plane element. Correspondingly, the first control plane element receives the first message from the access network element.

[0358] The first message includes a first signaling message and routing information for the first signaling message. The routing information for the first signaling message is used to route the first signaling message to the second control plane network element.

[0359] As one possible implementation, the routing information of the first signaling is determined based on the routing information of the second control plane network element. For example, if the routing information of the second control plane network element is its identifier, then the routing information of the first signaling includes the routing information of the second control plane network element; that is, the routing information of the first signaling includes the identifier of the second control plane network element. In other words, the first message may include both the first signaling and the identifier of the second control plane network element.

[0360] Optionally, the routing information of the first signaling may further include the identifier of the access network element, used to identify the access network element that sent the first signaling, or to identify the access network element to which the first terminal associated with the first signaling belongs (or accesses). Subsequently, when the second control plane network element sends downlink signaling, it may carry the identifier of the access network element so that the first control plane network element can perform downlink routing based on the identifier of the access network element. Furthermore, when the second control plane network element sends downlink signaling, it may also carry the identifier of the second control plane network element so that the access network element knows that the downlink signaling originates from the second control plane network element.

[0361] As one possible implementation, the first signaling can be encapsulated in a first protocol layer, for example, in a container of the first protocol layer. The routing information of the first signaling (i.e., the identifiers of the second control plane network elements and access network elements (optional)) can be carried in a second protocol layer, which is located below the first protocol layer. For example, the first protocol layer can be the NGAP layer, and the second protocol layer can be a new protocol layer (NL). The first and second protocol layers can also have other implementations and names, which are not specifically limited in this application.

[0362] Of course, the identifiers of the second control plane network elements and the access network elements (optional) can also be carried in other protocol layers, such as in the header of the first protocol layer. This application does not make specific limitations on this.

[0363] As one possible implementation, the destination IP address of the first message is the IP address of the first control plane network element. That is, it can be assumed that the destination IP address of the container at the first protocol layer sent by the access network element to the second network is the IP address of the first control plane network element.

[0364] As one possible implementation, the access network element sends the first message to the first control plane network element via a third connection. The first message may also include first indication information, which indicates that the first signaling is signaling associated with the first terminal. Refer to the relevant description in step S814a above; it will not be repeated here.

[0365] S915a: Based on the routing information of the first signaling, the first control plane network element determines to send the first signaling to the second control plane network element, and the first control plane network element sends a third message to the second control plane network element. Correspondingly, the second control plane network element receives the third message from the first control plane network element. The third message includes the first signaling.

[0366] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the routing information of the first signaling. For example, if the routing information of the first signaling matches the routing information of the first control plane network element, it determines to process the first signaling locally; if the routing information of the first signaling matches the routing information of the second control plane network element, it sends the first signaling to the second control plane network element.

[0367] For example, when the routing information of the second control plane network element is the identifier of the second control plane network element, matching the routing information of the first signaling with the routing information of the second control plane network element may include: the routing information of the first signaling including the identifier of the second control plane network element. For instance, when the first control plane network element receives a first message, based on the identifier of the second control plane network element included in the routing information of the first signaling, it learns that the first signaling needs to be further forwarded to the second control plane network element. That is, when the routing information of the first signaling includes the identifier of the second control plane network element, it determines that the first signaling should be sent to the second control plane network element.

[0368] As one possible implementation, if the first signaling is encapsulated in a container at the first protocol layer, and the identifiers of the second control plane network element and the access network element (optionally) are carried in the second protocol layer, after the first control plane network element receives the first message, it can determine from the identifier of the second control plane network element that the first signaling is sent to the second control plane network element, and then the first control plane network element does not parse the container at the first protocol layer.

[0369] As one possible implementation, sending a third message from the first control plane network element to the second control plane network element may include: sending the third message to the second control plane network element according to the first identifier mapping relationship. For example, the first control plane network element performs a conversion according to the first identifier mapping relationship to obtain the third message, and then sends the third message to the second control plane network element. The third message includes first signaling, and the destination IP address of the third message is the IP address of the second control plane network element.

[0370] For example, the first control plane network element can look up a mapping relationship (i.e., a first identifier mapping relationship) that includes the identifier of the second control plane network element, and use the IP address of the second control plane network element in the first identifier mapping relationship as the destination IP address of the third message. That is, the first control plane network element can refill the destination IP address of the first signaling with the IP address of the second control plane network element.

[0371] As one possible implementation, the first control plane network element sends the third message to the second control plane network element through the first connection. The third message may also include third indication information, which indicates that the first signaling is signaling associated with the first terminal. Refer to the relevant description in step S815a above; it will not be repeated here.

[0372] As one possible implementation, taking the first protocol layer as the NGAP layer and the second protocol layer as the NL layer as an example, a protocol stack architecture supporting the above steps S913-S915a can be shown in Figure 10. Referring to Figure 10, the first terminal and the access network element communicate through a control plane protocol stack, which includes layer 1 (L1), layer 2 (L2), and the RRC layer. The protocol stack of the access network element facing the first or second control plane element includes the IP layer, the Stream Control Transmission Protocol (SCTP) layer, the NL layer, and the NGAP layer. The protocol stack of the first control plane element includes the IP layer, the SCTP layer, and the NL layer. The protocol stack of the second control plane element includes the IP layer, the SCTP layer, the NL layer, and the NGAP layer. For example, the NGAP layer can be the NGAP layer defined in an existing protocol, or it can be an NGAP layer evolved from an existing NGAP layer; there is no limitation.

[0373] Based on the example shown in Figure 10, in step S913 above, the first terminal sends a first signaling message and network indication information to the access network element via an RRC message. For example, the RRC message may include RRC signaling, which the access network element converts into the first signaling message upon receiving it; or, the RRC message may include a non-access stratum (NAS) container, in which the first signaling message may be carried.

[0374] In step S914a above, after receiving the RRC message, the access network element converts the RRC message into an NGAP message. For example, it encapsulates the first signaling in an NGAP container and sequentially encapsulates the NGAP message in the order of NGAP layer, NL, SCTP layer, and IP layer to finally obtain the first message. If the network indication information indicates that the first signaling is signaling from the second network, then the identifier of the second control plane network element and the identifier of the access network element (optional) are carried at the NL layer.

[0375] In step S915a above, the first control plane network element parses the first message sequentially according to the IP layer, SCTP layer, and NL layer. If the NL layer carries the identifier of the second control plane network element, the NGAP container is not parsed. Instead, the message is encapsulated according to the SCTP layer and IP layer to obtain the third message, which is then sent to the second control plane network element.

[0376] For example, the protocol stack of the first control plane network element in Figure 10 above can be understood as the protocol stack when the first control plane network element performs forwarding. The protocol stack of the first control plane network element may not include the NL layer, but it can view or parse information in the NL layer.

[0377] In one possible implementation, when the first control plane network element forwards data, it may have a protocol stack for the access network element and a protocol stack for the second control plane network element. In this scenario, after receiving signaling from the access network element through the protocol stack for the access network element, the first control plane network element processes the signaling through the protocol stack for the second control plane network element and then sends it to the second control plane network element.

[0378] Furthermore, if the first signaling is the signaling of the first network, that is, the first control plane network element needs to process the first signaling locally, then the protocol stack of the first control plane network element also includes the NGAP layer.

[0379] S914b: The access network element sends a second message to the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0380] The second message includes first data and routing information for the first data, the routing information of which is used to route the first data to the second user plane network element.

[0381] As one possible implementation, the routing information of the first data is determined based on the routing information of the second user plane network element. For example, if the routing information of the second user plane network element is its identifier, then the routing information of the first data includes the routing information of the second user plane network element; that is, the routing information of the first data includes the identifier of the second user plane network element. In other words, the second message may include the first data and the identifier of the second user plane network element.

[0382] Optionally, the routing information of the first data may further include the identifier of the access network element, used to identify the access network element that sent the first data. When the second user plane network element subsequently sends downlink data, it may carry the identifier of the access network element so that the first user plane network element can perform downlink routing based on the identifier of the access network element.

[0383] As one possible implementation, the first data can be encapsulated in a third protocol layer, for example, in a container of the third protocol layer. The routing information of the first data (i.e., the identifiers of the second user plane network element and the access network element (optional)) can be carried in a fourth protocol layer, which is located below the third protocol layer. For example, the third protocol layer can be the GTP layer, and the fourth protocol layer can be the NL layer. The third and fourth protocol layers can also have other implementations and names, which are not specifically limited in this application.

[0384] Of course, the identifiers of the second user plane network element and the access network element (optional) can also be carried in other protocol layers, such as in the header of the third protocol layer. This application does not make specific limitations on this.

[0385] As one possible implementation, the destination IP address of the second message is the IP address of the first user plane network element. That is, it can be assumed that the destination IP address of the container at the third protocol layer sent by the access network element to the second network is the IP address of the first user plane network element.

[0386] As one possible implementation, the access network element sends the second message to the first user plane network element through a fourth connection. The second message may also include second indication information, which indicates that the first data is data associated with the first terminal. Refer to the relevant description in step S814b above; it will not be repeated here.

[0387] S915b: Based on the routing information of the first data, the first user plane network element determines to send the first data to the second user plane network element, and the first user plane network element sends a fourth message to the second user plane network element. Correspondingly, the second user plane network element receives the fourth message from the first user plane network element. The fourth message includes the first data.

[0388] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the routing information of the first data. For example, if the routing information of the first data matches the routing information of the first user plane network element, it determines to process the first data locally; if the routing information of the first data matches the routing information of the second user plane network element, it sends the first data to the second user plane network element.

[0389] For example, when the routing information of the second user plane network element is the identifier of the second user plane network element, matching the routing information of the first data with the routing information of the second user plane network element can include: the routing information of the first data includes the identifier of the second user plane network element. That is, when the first user plane network element receives the second message, based on the identifier of the second user plane network element included in the routing information of the first data, it learns that the first data needs to be further forwarded to the second user plane network element. In other words, when the routing information of the first data includes the identifier of the second user plane network element, it determines that the first data should be sent to the second user plane network element.

[0390] As one possible implementation, if the first data is encapsulated in a container at the third protocol layer, and the identifiers of the second user plane network element and the access network element (optionally) are carried at the fourth protocol layer, after the first user plane network element receives the second message, it can determine from the identifier of the second user plane network element that the first data was sent to the second user plane network element, and then the first user plane network element does not parse the container at the third protocol layer.

[0391] As one possible implementation, sending a fourth message from the first user plane network element to the second user plane network element may include: the first user plane network element performing a conversion based on a third identifier mapping relationship to obtain the fourth message, and then sending the fourth message to the second user plane network element. The fourth message includes first data, and the destination IP address of the fourth message is the IP address of the second user plane network element.

[0392] For example, the first user plane network element can look up the mapping relationship (i.e., the third identifier mapping relationship) that includes the identifier of the second user plane network element based on the identifier of the second user plane network element, and use the IP address in the identifier mapping relationship as the destination IP address of the fourth message. That is, the first user plane network element can refill the destination IP address of the first data with the IP address of the second user plane network element.

[0393] As one possible implementation, the first user plane network element sends the fourth message to the second user plane network element through the second connection. The fourth message may also include fourth indication information, which indicates that the first data is data associated with the first terminal. Refer to the relevant description in step S815b above; it will not be repeated here.

[0394] As one possible implementation, taking the third protocol layer as the GTP layer and the fourth protocol layer as the NL layer as an example, a protocol stack architecture supporting the above steps S913-S915b can be shown in Figure 11. Referring to Figure 11, the first terminal and the access network element communicate through a user plane protocol stack, which includes L1, L2, and SDAP layers. The protocol stack of the access network element facing the first or second user plane element includes the IP layer, the User Datagram Protocol (UDP) layer, the NL layer, and the GTP layer. The protocol stack of the first user plane element includes the IP layer, the UDP layer, and the NL layer. The protocol stack of the second user plane element includes the IP layer, the UDP layer, the NL layer, and the GTP layer. For example, the GTP layer can be a GTP layer defined in an existing protocol, or it can be a GTP layer evolved from an existing GTP layer; there are no restrictions.

[0395] Based on the example shown in Figure 11, in step S913 above, the first terminal and the access network element transmit the first data and network indication information through the SDAP layer. In step S914b above, after receiving the first data, the access network element converts it into GTP-encapsulated data, for example, encapsulating the first data in a GTP container, and then encapsulating the GTP container sequentially in the order of GTP layer, NL layer, UDP layer, and IP layer to obtain the second message. If the network indication information indicates that the first data is data from the second network, then the identifier of the second user plane network element and the identifier of the access network element (optional) are carried at the NL layer.

[0396] In step S915b above, the first user plane network element parses the second message sequentially according to the IP layer and UDP layer. If the identifier of the second user plane network element is found to be carried in the NL layer, the GTP container is not parsed, and the message is encapsulated again according to the UDP layer and IP layer to obtain the fourth message, which is then sent to the second user plane network element.

[0397] For example, the protocol stack of the first user plane network element in Figure 11 above can be understood as the protocol stack when the first user plane network element performs forwarding. The protocol stack of the first user plane network element may not include the NL layer, but it can still view or parse information from the NL layer.

[0398] In one possible implementation, when the first user plane network element forwards data, it may have a protocol stack for the access network element and a protocol stack for the second user plane network element. In this scenario, after receiving data from the access network element through the protocol stack for the access network element, the first user plane network element processes the data through the protocol stack for the second user plane network element and then sends it to the second user plane network element.

[0399] Furthermore, if the first data is data from the first network, that is, the first user plane network element needs to process the first data locally, then the protocol stack of the first user plane network element also includes the GTP layer.

[0400] S914c, The access network element sends a first message to the first control plane network element based on the routing information of the first control plane network element. Correspondingly, the first control plane network element receives the first message from the access network element.

[0401] The first message includes a first signaling message and its routing information. The routing information of the first signaling message includes the identifier of the first control plane network element, and may also include the identifier of the access network element (optional). The encapsulation and other implementation of the first signaling message and its routing information can be found in the relevant description in step S914a above, and will not be repeated here.

[0402] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the routing information of the first signaling. For example, if the routing information of the first signaling includes the identifier of the first control plane network element, the first signaling is processed, such as parsing the NGAP container. Refer to the relevant description in step S915a above; it will not be repeated here.

[0403] S914d, The access network element sends a second message to the first user plane network element based on the routing information of the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0404] The second message includes first data and routing information for the first data. The routing information for the first data includes the identifier of the first user plane network element, and may also include the identifier of the access network element (optional). The encapsulation and other implementation of the first data and its routing information can be found in the relevant description in step S914b above, and will not be repeated here.

[0405] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the routing information of the first data. For example, if the routing information of the first data includes the identifier of the first user plane network element, the first data can be processed, such as parsing the GTP container. Refer to the relevant description in step S915b above; it will not be repeated here.

[0406] In one possible implementation, the communication method shown in FIG9 further includes step S900 (not shown in the figure). The implementation of step S900 is the same as that of step S700, and can be referred to the relevant description of S700 above, which will not be repeated here.

[0407] Based on the above description, when the access network element receives the first information from the first terminal, and the first information is signaling, the access network element sends the signaling to the first control plane element. Further, as shown in Figure 12, when the first information is signaling for the first network, the signaling can be encapsulated in an NGAP container, and the access network element also sends the identifier of the first control plane element (represented as MM1 id) and the identifier of the access network element (represented as RAN id, optional); when the first information is signaling for the second network, the signaling can be encapsulated in an NGAP container, and the access network element also sends the identifier of the second control plane element (represented as MM2 id) and the identifier of the access network element (represented as RAN id, optional).

[0408] When the first information is data, the access network element sends the data to the first user plane network element. Further, as shown in Figure 13, when the first information is data from the first network, the data can be encapsulated in a GTP container, and the access network element also sends the identifier of the first user plane network element (represented as UPF1 id) and the identifier of the access network element (represented as RAN id, optional); when the first information is data from the second network, the data can be encapsulated in a GTP container, and the access network element also sends the identifier of the second user plane network element (represented as UPF2 id) and the identifier of the access network element (represented as RAN id, optional).

[0409] It should be noted that the double-arrow lines between the access network element and the second control plane element in Figure 12 represent the logical path between them. In reality, signaling sent to the second control plane element needs to be forwarded by the first control plane element. Similarly, the double-arrow lines between the access network element and the second user plane element in Figure 13 also represent the logical path between them. In reality, data sent to the second user plane element needs to be forwarded by the first user plane element.

[0410] Furthermore, in the presence of multiple second networks, the first control plane network element can assign different identifiers to control plane network elements in different second networks, and the first user plane network element can assign different identifiers to user plane network elements in different second networks. For example, the first network is connected to second network 1 and second network 2. It can assign ID 2 to MM2 in second network 1, and ID 2' to UPF2 in second network 1; it can assign ID 3 to MM3 in second network 2, and ID 3' to UPF3 in second network 2.

[0411] The routing of uplink signaling / data has been explained above. For downlink signaling, the second control plane network element sends the downlink signaling and its routing information to the first control plane network element. This routing information can be the identifier of the access network element. The first control plane network element forwards the downlink signaling to the corresponding access network based on the access network element's identifier. Furthermore, the first control plane network element can also carry the identifier of the second control plane network element in the message carrying the downlink signaling. After receiving this message, the access network element can determine that the signaling carried in the message belongs to the second network based on the second control plane network element's identifier, and subsequently forward the signaling to the first terminal, indicating that it belongs to the second network.

[0412] Furthermore, the messages carrying downlink signaling sent by the second control plane network element and the first control plane network element may also carry indication information to indicate the terminal associated with the signaling. The implementation of this indication information is similar to the first indication information in step S914a and the third indication information in step S915a, except that the identifier of the access network element in the indication information needs to be replaced with the identifier of the second control plane network element. Please refer to the relevant descriptions above, which will not be repeated here.

[0413] Similarly, for downlink data, the second user plane network element sends the downlink data and its routing information to the first user plane network element. This routing information can be the identifier of the access network element. The first user plane network element forwards the downlink data to the corresponding access network based on the access network element's identifier. Furthermore, the first user plane network element can also carry the identifier of the second user plane network element in the message carrying the downlink data. Upon receiving this message, the access network element can determine that the data carried in the message belongs to the second network based on the second user plane network element's identifier, and subsequently forward the data to the first terminal, indicating that the data belongs to the second network.

[0414] Furthermore, the messages carrying downlink data sent by the second data plane network element and the first data plane network element may also carry indication information to indicate the terminal associated with the data. The implementation of this indication information is similar to the second indication information in step S914b and the fourth indication information in step S915b, except that the identifier of the access network element in the indication information needs to be replaced with the identifier of the second data plane network element. Please refer to the relevant descriptions above, which will not be repeated here.

[0415] In the above scheme, when an access network element sends signaling to a first control plane network element, it distinguishes whether the signaling is intended for the first network or the second network using different network element identifiers. This allows the first control plane network element to determine whether to process the signaling locally or forward it based on the network element identifier. If forwarding is required, it can further perform corresponding routing based on the network element identifier. Furthermore, when an access network element sends data to a first user plane network element, it distinguishes whether the data is intended for the first network or the second network using different network element identifiers. This allows the first user plane network element to perform appropriate processing or routing based on the network element identifier. This enables signaling / data transmission between the access network element and the second network, supports the separation of the core network elements of the second network from the first network, and thus meets various user needs of the second network, such as meeting increasingly higher mobility requirements and improving user experience.

[0416] In a third possible implementation scenario, in scenario one above, where the routing information of the second control plane network element is the identifier associated with the first connection, and the routing information of the second user plane network element is the identifier associated with the second connection, a communication process provided in this application can be as shown in Figure 14. Here, the first connection is the connection between the second control plane network element and the first control plane network element, and the second connection is the connection between the second user plane network element and the first user plane network element. Referring to Figure 14, this communication process may include the following steps:

[0417] S1401-S1403 are the same as steps S801-S803 above. Please refer to the relevant explanations of steps S801-S803 above. They will not be repeated here.

[0418] S1404. The first control plane network element allocates routing information of the second control plane network element to the second control plane network element.

[0419] In one possible implementation, the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection (e.g., it can be represented as the identifier of the first connection <-> the identifier of the third connection), or it includes the identifier of the connection between the access network element and the second control plane network element. The connection between the access network element and the second control plane network element includes the first connection and the third connection. The first connection is the connection between the first control plane network element and the second control plane network element, and the third connection is the connection between the access network element and the first control plane network element. Refer to the relevant descriptions of the first and third connections after step S812 above; they will not be repeated here.

[0420] For example, the identifier of the first connection can be connection identifier 1, or it can include both first identifier 1 and first identifier 2. The identifier of the third connection can be connection identifier 3, or it can include the RAN UE NGAP ID and AM / MM / SM UE NGAP ID. Refer to the relevant explanations of the identifiers of the first and third connections after step S812 above; they will not be repeated here. Furthermore, first identifier 1 and / or first identifier 2 can be collectively referred to as the first identifier, and RAN UE NGAP ID and / or AM / MM / SM UE NGAP ID can be collectively referred to as the UE NGAP ID.

[0421] For example, taking the identifier of the first connection as the first identifier and the identifier of the third connection as the UE NGAP ID, the routing information of the second control plane network element can be represented as: first identifier <-> UE NGAP ID.

[0422] In one possible implementation, the first control plane network element can establish a connection (referred to as the first connection) between the first control plane network element and the second control plane network element. The first connection can be established before or after the allocation of routing information to the second control plane network element; there is no limitation on this. The third connection can be established before step S1402. Refer to the relevant description of establishing a connection between the access network element and the first control plane network element in step S702 above; it will not be repeated here.

[0423] As one possible implementation, the third connection between the access network element and the first control plane network element can be used to transmit signaling for the first network and the second network. The identifier of the third connection when used to transmit signaling for the first network can be different from the identifier of the third connection when used to transmit signaling for the second network.

[0424] For example, the identifier for the third connection used to transmit signaling for the first network can be RAN UE NGAP ID 1 or AM / MM / SM UE NGAP ID 1. The identifier for the third connection used to transmit signaling for the second network can be RAN UE NGAP ID 2 or AM / MM / SM UE NGAP ID 2.

[0425] It should be noted that, unless otherwise specified, the identifier of the third connection in the following embodiments of this application refers to the identifier of the third connection included in the routing information of the second control plane network element.

[0426] As another possible implementation, a third connection can be established between the access network element and the first control plane network element. This third connection is used to transmit signaling of the first network. That is, signaling of the second network can be transmitted through the third connection, and signaling of the first network can be transmitted through the third connection.

[0427] As one possible implementation, the first control plane network element establishes a mapping relationship between the IP address of the access network element + the identifier of the third connection, and the identifier of the first connection + the IP address of the second control plane network element (denoted as the first connection mapping relationship). For example, taking the second control plane network element as MM2, the identifier of the first connection as the first identifier, and the identifier of the third connection as the UE NGAP ID, the first connection mapping relationship can be expressed as: IP address of the access network element + UE NGAP ID <-> IP address of MM2 + first identifier.

[0428] Alternatively, the first connection mapping relationship can also be: the mapping relationship between the identifier of the connection between the access network element and the second control plane network element and the IP address of the second control plane network element.

[0429] The IP address of a network element (such as an access network element and / or a second control plane network element) can also be replaced with other identification information of the network element, such as an ID, without restriction.

[0430] S1405-S1409 are the same as steps S805-S809 above. Please refer to the relevant explanations in steps S805-S809 above. They will not be repeated here.

[0431] S1410, the first control plane network element sends a first request message to the first user plane network element. Correspondingly, the first user plane network element receives the first request message from the first control plane network element.

[0432] The first request information is used to request routing information from the second user plane network element. For example, the first request information may include the IP address of the second user plane network element.

[0433] As one possible implementation, after receiving the first request information, the first user plane network element can allocate routing information to the second user plane network element. The routing information of the second user plane network element includes the identifiers of the second connection and the fourth connection (e.g., it can be represented as the identifier of the first connection <-> the identifier of the third connection), or it includes the identifier of the connection between the access network element and the second user plane network element.

[0434] The connection between the access network element and the second user plane network element includes a second connection and a fourth connection. The second connection is the connection between the first user plane network element and the second user plane network element, and the fourth connection is the connection between the access network element and the first user plane network element. Please refer to the relevant descriptions of the second connection and the fourth connection after step S812 above, which will not be repeated here.

[0435] For example, the identifier of the second connection can be connection identifier 2, or it can include both second identifier 1 and second identifier 2. The identifier of the fourth connection can be connection identifier 4, or it can include TEID 1 and TEID 2. Refer to the relevant descriptions of the identifiers of the second and fourth connections after step S812 above; they will not be repeated here. Furthermore, second identifier 1 and / or second identifier 2 can be collectively referred to as the second identifier, and TEID 1 and / or TEID 2 can be collectively referred to as TEID.

[0436] For example, taking the identifier of the second connection as the second identifier and the identifier of the fourth connection as TEID, the routing information of the second user plane network element can be represented as: second identifier <-> TEID.

[0437] For example, the identifier of the connection between the access network element and the second user plane network element can also be called the end-to-end identifier between the access network element and the second user plane network element, and the two can be used interchangeably.

[0438] As one possible implementation, the fourth connection between the access network element and the first user plane network element can be used to transmit data from the first network and data from the second network. The identifier of the fourth connection when used to transmit data from the first network can be different from the identifier of the fourth connection when used to transmit data from the second network.

[0439] As another possible implementation, a fourth connection can be established between the access network element and the first user plane network element. This fourth connection is used to transmit data from the first network. That is, data from the second network can be transmitted through the fourth connection, and data from the first network can be transmitted through the fourth connection. Refer to the relevant description of the third connection in step S1404 above; it will not be repeated here.

[0440] In one possible implementation, the first user plane network element establishes a mapping relationship between the IP address of the access network element + the identifier of the fourth connection and the identifier of the second connection + the IP address of the second user plane network element (denoted as the second connection mapping relationship). For example, taking the second user plane network element as UPF2, the identifier of the second connection as the second identifier, and the identifier of the fourth connection as TEID, the second connection mapping relationship can be expressed as: IP address of the access network element + TEID <-> IP address of UPF2 + second identifier.

[0441] Alternatively, the second connection mapping relationship can also be: the mapping relationship between the identifier of the connection between the access network element and the second user plane network element and the IP address of the second user plane network element.

[0442] The IP address of a network element (such as an access network element and / or a second user plane network element) can be replaced with other identification information of the network element, such as an ID, without restriction.

[0443] S1411, the first user plane network element sends the routing information of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the routing information of the second user plane network element from the first user plane network element.

[0444] For example, a first user plane network element may send a second connection mapping relationship to a first control plane network element, the second connection mapping relationship including the routing information of the second user plane network element.

[0445] Optionally, the first user plane network element may also send an identifier for the fourth connection used to transmit data of the first network to the first control plane network element, or send an identifier associated with the fourth connection.

[0446] As one possible implementation, steps S1404 and S1410-S1411 above can be understood as an implementation of the first control plane network element obtaining routing information from the second control plane network element and the second user plane network element.

[0447] S1412, the first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0448] As one possible implementation, the first control plane network element sends a first connection mapping relationship and a second connection mapping relationship to the access network element. The first connection mapping relationship carries the routing information of the second control plane network element, and the second connection mapping relationship carries the routing information of the second user plane network element.

[0449] Optionally, the first control plane network element may also send the identifier of the second network, and the identifiers of the terminal / service / task corresponding to the second control plane network element and the second user plane network element to the access network element. Refer to the relevant explanation in step S704 above; it will not be repeated here.

[0450] As one possible implementation, the first control plane network element can also send an identifier for a third connection used to transmit signaling for the first network to the access network element, or send an identifier for a third connection. The first control plane network element can also send an identifier for a fourth connection used to transmit data for the first network to the access network element, or send an identifier for a fourth connection.

[0451] Optionally, after step S1412, the access network element may also send a service response message to the first terminal. Refer to the foregoing explanation of the service response message; further details will not be repeated here.

[0452] Steps S1401-S1412 described above can be understood as the initial establishment or initial configuration phase. After step S1412, signaling / data transmission of the second network can proceed. For example, after step S1412, the method further includes the following steps:

[0453] S1413, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0454] The network indication information is used to indicate whether the first information is from a first network or a second network. The first information is signaling or data. Refer to the relevant explanation in step S813 above.

[0455] As one possible implementation, after receiving the first information and the network indication information, the access network element can determine whether the first information is from the first network or the second network based on the network indication information. Furthermore, the access network element can identify whether the first information is signaling or data, and thus can look up the routing information of the second control plane network element or the information of the second user plane network element from the routing mapping table based on the network indication information. Refer to the relevant explanation in step S706a above; it will not be repeated here.

[0456] Specifically, if the first information is a first signaling message and the network indication information indicates that the first information is information of the second network, then steps S1414a-S1415a are executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then steps S1414b-S1415b are executed; if the first information is a first signaling message and the network indication information indicates that the first information is information of the first network, then step S1414c is executed; and if the first information is first data and the network indication information indicates that the first information is information of the second network, then step S1414d is executed.

[0457] S1414a, The access network element sends a first message to the first control plane network element. Correspondingly, the first control plane network element receives the first message from the access network element.

[0458] The first message includes a first signaling message and routing information for the first signaling message. The routing information for the first signaling message is used to route the first signaling message to the second control plane network element.

[0459] As one possible implementation, the routing information of the first signaling is determined based on the routing information of the second control plane network element. For example, when the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, or includes the identifier of the connection between the access network element and the second control plane network element, the routing information of the first signaling includes the routing information of the second control plane network element. For instance, the routing information of the first signaling includes the identifier of the first connection and the identifier of the third connection, or the routing information of the first signaling includes the identifier of the connection between the access network element and the second control plane network element. For example, the first message may include the first signaling, the identifier of the first connection, and the identifier of the third connection; or, the first message may include the first signaling and the identifier of the connection between the access network element and the second control plane network element.

[0460] Alternatively, the routing information of the first signaling may include part of the routing information of the second control plane network element. For example, if the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, the routing information of the first signaling may include the identifier of the third connection in the routing information of the second control plane network element. That is, the first message may include the first signaling and the identifier of the third connection.

[0461] As one possible implementation, the first signaling can be encapsulated in a first protocol layer, for example, in a container of the first protocol layer. The routing information of the first signaling can be carried in the header of the first protocol layer. For example, the first protocol layer can be the NGAP layer, but it can also have other implementations and names; this application does not specifically limit its implementation.

[0462] As one possible implementation, the destination IP address of the first message is the IP address of the first control plane network element. That is, it can be assumed that the destination IP address of the container at the first protocol layer sent by the access network element to the second network is the IP address of the first control plane network element.

[0463] S1415a: Based on the routing information of the first signaling, the first control plane network element determines to send the first signaling to the second control plane network element, and the first control plane network element sends a third message to the second control plane network element. Correspondingly, the second control plane network element receives the third message from the first control plane network element. The third message includes the first signaling.

[0464] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the routing information of the first signaling. For example, if the routing information of the first signaling matches the routing information of the first control plane network element, it determines to process the first signaling locally; if the routing information of the first signaling matches the routing information of the second control plane network element, it sends the first signaling to the second control plane network element.

[0465] For example, when the routing information of the second control plane network element includes the identifiers of the first connection and the third connection, matching the routing information of the first signaling with the routing information of the second control plane network element can include: the routing information of the first signaling including the identifiers of the first connection and the third connection, or the routing information of the first signaling including the identifier of the third connection. For instance, when the first control plane network element receives a first message, based on the identifiers of the first connection and the third connection included in the routing information of the first signaling, or based on the identifier of the third connection included in the routing information of the first signaling, it can determine that the first signaling needs to be further forwarded to the second control plane network element. That is, if the routing information of the first signaling includes the identifiers of the first connection and the third connection, or if the routing information of the first signaling includes the identifier of the third connection, it determines that the first signaling should be sent to the second control plane network element.

[0466] Alternatively, if the routing information of the second control plane network element includes an identifier of the connection between the access network element and the second control plane network element, then matching the routing information of the first signaling with the routing information of the second control plane network element may include: the routing information of the first signaling including an identifier of the connection between the access network element and the second control plane network element. In other words, if the routing information of the first signaling includes an identifier of the connection between the access network element and the second control plane network element, it is determined that the first signaling will be sent to the second control plane network element.

[0467] As one possible implementation, if the first signaling is encapsulated in a container at the first protocol layer and the routing information of the first signaling is carried in the header of the first protocol layer, after the first control plane network element receives the first message, it can determine from the routing information of the first signaling that the first signaling is sent to the second control plane network element, and then the first control plane network element does not parse the container at the first protocol layer.

[0468] As one possible implementation, sending a third message from the first control plane network element to the second control plane network element may include: the first control plane network element sending the third message to the second control plane network element according to the first connection mapping relationship. For example, the first control plane network element performs a conversion according to the first connection mapping relationship to obtain the third message, and then sends the third message to the second control plane network element. The third message includes first signaling, and the destination IP address of the third message is the IP address of the second control plane network element.

[0469] For example, the first control plane network element can look up a mapping relationship (i.e., the first connection mapping relationship) that includes the identifier of the first connection, the identifier of the third connection, or the identifier of the connection between the access network element and the second control plane network element, and use the IP address of the second control plane network element in the first connection mapping relationship as the destination IP address of the third message. That is, the first control plane network element can refill the destination IP address of the first signaling with the IP address of the second control plane network element.

[0470] As one possible implementation, the third message may also include the identifier of the first connection or the identifier of the connection between the access network element and the second control plane element.

[0471] For example, taking the first connection mapping relationship as the IP address of the access network element (denoted as IP address 1) + UE NGAP ID <-> MM2's IP address (denoted as IP address 2) + first identifier as an example, based on the above steps 1414a-S1415a, it can be realized that: the access network element with IP address 1 sends the signaling associated with the UE NGAP ID to the first control plane network element, and the first control plane network element can send the signaling to MM2 with IP address 2. In addition, the message carrying the signaling sent by the first control plane network element to MM2 may also include the first identifier.

[0472] As one possible implementation, when the first control plane network element sends a first connection mapping relationship to the second control plane network element, after the second control plane network element receives a third message carrying the identifier of the first connection, it can know from the access network element associated with the third connection that the signaling comes from the first connection mapping relationship.

[0473] As one possible implementation, taking the NGAP layer as the first protocol layer as an example, a protocol stack architecture supporting steps S1413-S1415a can be shown in Figure 15. The difference between the protocol stack shown in Figure 15 and the protocol stack shown in Figure 10 is that the protocol stack shown in Figure 15 lacks the NL layer. For other implementations, please refer to the relevant descriptions of the protocol stack shown in Figure 10, which will not be repeated here.

[0474] Based on the example shown in Figure 15, in step S1413 above, the first terminal sends the first signaling and network indication information to the access network element via an RRC message. Refer to the relevant explanation shown in Figure 10 above; it will not be repeated here.

[0475] In step S1414a above, after receiving the RRC message, the access network element converts the RRC message into an NGAP message. For example, it encapsulates the first signaling in an NGAP container and sequentially encapsulates the NGAP message in the order of NGAP layer, SCTP layer, and IP layer to finally obtain the first message. If the network indication information indicates that the first signaling is the signaling of the second network, then the header of the NGAP layer carries the identifier of the first connection and the identifier of the third connection, or carries the identifier of the third connection.

[0476] In step S1415a above, the first control plane network element parses the first message sequentially according to the IP layer and SCTP layer. If it finds that the first message carries the identifier of the first connection and the identifier of the third connection, or carries the identifier of the third connection, it does not parse the NGAP container, but encapsulates it according to the SCTP layer and IP layer to obtain the third message, and sends the third message to the second control plane network element.

[0477] S1414b: The access network element sends a second message to the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0478] The second message includes first data and routing information for the first data, the routing information of which is used to route the first data to the second user plane network element.

[0479] As one possible implementation, the routing information of the first data is determined based on the routing information of the second user plane network element. For example, when the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, or includes the identifier of the connection between the access network element and the second user plane network element, the routing information of the first data includes the routing information of the second user plane network element. For instance, the routing information of the first data includes the identifier of the second connection and the identifier of the fourth connection, or the routing information of the first data includes the identifier of the connection between the access network element and the second user plane network element. For example, the second message may include the first data, the identifier of the second connection, and the identifier of the fourth connection; or, the second message may include the first data and the identifier of the connection between the access network element and the second user plane network element.

[0480] Alternatively, the routing information of the first data may include part of the routing information of the second user plane network element. For example, if the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, the routing information of the first data may include the identifier of the fourth connection in the routing information of the second user plane network element. That is, the second message may include the first data and the identifier of the fourth connection.

[0481] As one possible implementation, the first data can be encapsulated in a third protocol layer, for example, in a container of the third protocol layer. The routing information of the first data can be carried in the header of the third protocol layer. For example, the third protocol layer can be the GTP layer, but it can also have other implementations and names; this application does not specifically limit its implementation.

[0482] As one possible implementation, the destination IP address of the second message is the IP address of the first user plane network element. That is, it can be assumed that the destination IP address of the container at the third protocol layer sent by the access network element to the second network is the IP address of the first user plane network element.

[0483] S1415b: Based on the routing information of the first data, the first user plane network element determines to send the first data to the second user plane network element, and the first user plane network element sends a fourth message to the second user plane network element. Correspondingly, the second user plane network element receives the fourth message from the first user plane network element. The fourth message includes the first data.

[0484] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the routing information of the first data. For example, if the routing information of the first data matches the routing information of the first user plane network element, it determines to process the first data locally; if the routing information of the first data matches the routing information of the second user plane network element, it sends the first data to the second user plane network element.

[0485] For example, when the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, matching the routing information of the first data with the routing information of the second user plane network element may include: the routing information of the first data including the identifier of the second connection and the identifier of the fourth connection, or the routing information of the first data including the identifier of the fourth connection. That is, if the routing information of the first data includes the identifier of the second connection and the identifier of the fourth connection, or includes the identifier of the fourth connection, it is determined that the first data will be sent to the second user plane network element.

[0486] Alternatively, if the routing information of the second user plane network element includes an identifier of the connection between the access network element and the second user plane network element, the matching of the routing information of the first data with the routing information of the second user plane network element may include: the routing information of the first data includes an identifier of the connection between the access network element and the second user plane network element.

[0487] As one possible implementation, if the first data is encapsulated in a container of the third protocol layer and the routing information of the first data is carried in the header of the third protocol layer, after the first user plane network element receives the second message, it can determine from the routing information of the first data that the first data is sent to the second user plane network element. In this case, the first user plane network element does not parse the container of the third protocol layer.

[0488] As one possible implementation, sending a fourth message from the first user plane network element to the second user plane network element may include: the first user plane network element sending the fourth message to the second user plane network element according to the second connection mapping relationship. For example, the first user plane network element performs a conversion according to the second connection mapping relationship to obtain the fourth message, and then sends the fourth message to the second user plane network element. The fourth message includes first data, and the destination IP address of the fourth message is the IP address of the second user plane network element.

[0489] For example, the first user plane network element can look up a mapping relationship (i.e., the second connection mapping relationship) that includes the identifier of the second connection, the identifier of the fourth connection, or the identifier of the connection between the access network element and the second user plane network element, and use the IP address of the second user plane network element in the second connection mapping relationship as the destination IP address of the fourth message. That is, the first user plane network element can refill the destination IP address of the first data with the IP address of the second user plane network element.

[0490] As one possible implementation, the fourth message may also include the identifier of the second connection or the identifier of the connection between the access network element and the second user plane network element.

[0491] For example, taking the second connection mapping relationship as the IP address of the access network element (denoted as IP address 3) + TEID <-> the IP address of UPF2 (denoted as IP address 4) + the second identifier, based on the above steps 1414b-S1415b, it can be realized that: the access network element with IP address 3 sends the signaling associated with TEID to the first user plane network element, and the first user plane network element can send the data to UPF2 with IP address 4. In addition, the message carrying the data sent by the first user plane network element to UPF2 may also include the second identifier.

[0492] As one possible implementation, when the first user plane network element sends the second connection mapping relationship to the second user plane network element, after the second user plane network element receives the fourth message carrying the second connection identifier, it can know from the access network element associated with the fourth connection that the data comes from the second connection mapping relationship.

[0493] As one possible implementation, taking the GTP layer as the third protocol layer as an example, a protocol stack architecture supporting steps S1413-S1415b can be shown in Figure 16. The difference between the protocol stack shown in Figure 16 and the protocol stack shown in Figure 11 is that the protocol stack shown in Figure 16 lacks the NL layer. For other implementations, please refer to the relevant descriptions of the protocol stack shown in Figure 11, which will not be repeated here.

[0494] Based on the example shown in Figure 16, in step S1413 above, the first terminal and the access network element transmit the first data and network indication information through the SDAP layer. In step S1414b above, after receiving the first data, the access network element converts it into GTP-encapsulated data, for example, encapsulating the first data in a GTP container, and then encapsulating the GTP container sequentially according to the order of GTP layer, UDP layer, and IP layer to obtain the second message. If the network indication information indicates that the first data is data from the second network, then the header of the GTP layer carries the identifier of the second connection and the identifier of the fourth connection, or carries the identifier of the fourth connection.

[0495] In step S1415b above, the first user plane network element parses the second message sequentially according to the IP layer and UDP layer order. If it finds that the second message carries the identifier of the second connection and the identifier of the fourth connection, or carries the identifier of the fourth connection, it does not parse the GTP container, but encapsulates it according to the UDP layer and IP layer order to obtain the fourth message, and sends the fourth message to the second user plane network element.

[0496] S1414c, The access network element sends a first message to the first control plane network element based on the routing information of the first control plane network element. Correspondingly, the first control plane network element receives the first message from the access network element.

[0497] The first message includes a first signaling message and its routing information. The routing information of the first signaling message includes an identifier for the third connection used to transmit signaling to the first network, or includes an identifier for the third connection. The encapsulation and other implementation details of the first signaling message and its routing information can be found in the relevant descriptions in step S1414a above, and will not be repeated here.

[0498] As one possible implementation, after receiving the first message, the first control plane network element can determine whether to process the first signaling locally or forward it based on the routing information of the first signaling. For example, if the routing information of the first signaling includes an identifier for the third connection used to transmit signaling for the first network, or includes an identifier for the third connection, the first signaling is processed, such as parsing the NGAP container. Refer to the relevant description in step S1415a above; it will not be repeated here.

[0499] S1414d, The access network element sends a second message to the first user plane network element based on the routing information of the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0500] The second message includes first data and routing information for the first data. The routing information for the first data includes an identifier for the fourth connection used to transmit data from the first network, or includes an identifier for the fourth connection. The encapsulation and other implementation details of the first data and its routing information can be found in the relevant descriptions in step S1414b above, and will not be repeated here.

[0501] As one possible implementation, after receiving the second message, the first user plane network element can determine whether to process the first data locally or forward it based on the routing information of the first data. For example, if the routing information of the first data includes an identifier for the fourth connection used to transmit data from the first network, or includes an identifier for the fourth connection, the first data can be processed, such as by parsing the GTP container. Refer to the relevant description in step S1415b above; it will not be repeated here.

[0502] In one possible implementation, the communication method shown in FIG14 further includes step S1400 (not shown in the figure). The implementation of step S1400 is the same as that of step S700, and can be referred to the relevant description of S700 above, which will not be repeated here.

[0503] Based on the above description, in one possible implementation, the access network element receives first information from the first terminal. If the first information is signaling, the access network element sends the signaling to the first control plane element. Further, as shown in Figure 17, if the first information is signaling from the second network, the signaling can be encapsulated in an NGAP container. The access network element also sends an identifier for the third connection (such as the UE NGAP ID). After receiving the NGAP container sent by the access network element, the first control plane element forwards the NGAP container to the second control plane element and also sends the identifier for the first connection.

[0504] When the first information is data, the access network element sends the data to the first user plane network element. Further, as shown in Figure 18, when the first information is data from the second network, the data can be encapsulated in a GTP container, and the access network element also sends an identifier for the fourth connection (such as TEID). After receiving the GTP container sent by the access network element, the first user plane network element forwards the GTP container to the second user plane network element and also sends an identifier for the second connection.

[0505] The routing of uplink signaling / data has been explained above. For downlink signaling, the second control plane network element sends downlink signaling and its routing information to the first control plane network element. This routing information can be the identifier of a first connection and the identifier of a third connection, or it can be the identifier of the first connection, or it can be the identifier of a connection between the access network element and the second control plane network element. The first control plane network element looks up the first connection mapping relationship based on the downlink signaling routing information and forwards the downlink signaling to the access network element in the first connection mapping relationship. Furthermore, the first control plane network element can also carry the identifier of the third connection in the message carrying the downlink signaling. After receiving this message, the access network element can determine that the signaling carried in the message belongs to the second network based on the identifier of the third connection and the first connection mapping relationship. Subsequently, it can forward the signaling to the first terminal and indicate that the signaling belongs to the second network.

[0506] Similarly, for downlink data, the second user plane network element sends the downlink data and its routing information to the first user plane network element. This routing information can be the identifier of the second connection and the identifier of the fourth connection, or it can be the identifier of the second connection, or it can be the identifier of the connection between the access network element and the second user plane network element. The first user plane network element looks up the second connection mapping relationship based on the downlink data routing information and forwards the downlink data to the access network element in the second connection mapping relationship. Furthermore, the first user plane network element can also carry the identifier of the fourth connection in the message carrying the downlink data. After receiving this message, the access network element can determine that the data carried in the message belongs to the second network based on the identifier of the fourth connection and the second connection mapping relationship. Subsequently, it can forward the data to the first terminal and indicate that the data belongs to the second network.

[0507] In the scheme shown in Figure 14 above, the signaling interaction between the access network element, the first control plane network element, and the second control plane network element carries the identifier of the first connection and / or the identifier of the third connection. The signaling interaction between the access network element, the first user plane network element, and the second user plane network element carries the identifier of the second connection and / or the identifier of the fourth connection. The identifiers of the first connection, the third connection, the second connection, and the fourth connection are all associated with the first terminal, or in other words, at the terminal level. Therefore, based on these identifiers, it can be indicated that the transmitted signaling / data is the signaling / data associated with the first terminal.

[0508] In the above scheme, for signaling transmission, there is a mapping relationship between the identifier of the third connection between the access network element and the first control plane element, and between the identifier of the first connection between the first control plane element and the second control plane element. Therefore, the first control plane element can forward uplink signaling in a message carrying uplink signaling and the identifier of the third connection to the second control plane element based on this mapping relationship; and forward downlink signaling in a message carrying downlink signaling and the identifier of the first connection to the access network element based on this mapping relationship. For data transmission, there is a mapping relationship between the identifier of the fourth connection between the access network element and the first user plane element, and between the identifier of the second connection between the first user plane element and the second user plane element. Therefore, the first user plane element can also forward uplink and downlink data based on this mapping relationship. In other words, it can realize signaling / data transmission between the access network element and the second network, support the separation of the core network element of the second network from the first network, and thus meet the various needs of users of the second network, such as meeting increasingly higher mobility requirements and improving user experience.

[0509] In the fourth possible implementation scenario, in scenario two above, where the routing information of the second control plane network element is the port number associated with the second control plane network element, and the routing information of the second user plane network element is the port number associated with the second user plane network element, the communication process provided in this application can be as shown in Figure 19. Referring to Figure 19, this communication process may include the following steps:

[0510] S1901-S1903 are the same as steps S801-S803 above. Please refer to the relevant explanations of steps S801-S803 above. They will not be repeated here.

[0511] S1904-S1908 are the same as steps S805-S809 above. Please refer to the relevant explanations of steps S805-S809 above. They will not be repeated here.

[0512] S1909, the first control plane network element sends a second request message to the first user plane network element. Correspondingly, the first user plane network element receives the second request message from the first control plane network element.

[0513] The second request information is used to request routing information from the second control plane network element and the second user plane network element. For example, the second request message may include the IP addresses of the second control plane network element and the second user plane network element.

[0514] As one possible implementation, after receiving the second request information, the first user plane network element can allocate routing information to the second control plane network element and the second user plane network element. The routing information for the second control plane network element is its port number, and the routing information for the second user plane network element is its port number. The implementation of the first user plane network element allocating routing information to the second control plane network element can refer to the implementation of the first control plane network element in step S804 above, and the implementation of the first user plane network element allocating routing information to the second user plane network element can refer to the implementation of the first user plane network element in step S810 above, and will not be repeated here.

[0515] For example, the port number of the second control plane network element and the port number of the second user plane network element can be the same or different. If they are the same, the subsequent access network element can send additional indication information to indicate whether signaling or data is being sent to the first user plane network element. The following embodiments of this application illustrate this using the example of different port numbers.

[0516] As one possible implementation, the first user plane network element can establish a fifth NAT mapping relationship and a third NAT mapping relationship. Optionally, the first user plane network element can also establish a sixth NAT mapping relationship and a fourth NAT mapping relationship.

[0517] The fifth NAT mapping is similar to the first NAT mapping, except that the IP address of the first control plane network element in the first NAT mapping is replaced with the IP address of the first user plane network element. That is, the fifth NAT mapping can include: IP address of the first user plane network element + port number of the second control plane network element -> IP address of the second control plane network element. For example, it can be represented as IP address of UPF1 + port2 -> IP address of MM2. Refer to the relevant explanation of the first NAT mapping above; it will not be repeated here.

[0518] The sixth NAT mapping is similar to the second NAT mapping described above, except that the IP address of the first control plane network element in the second NAT mapping is replaced with the IP address of the first user plane network element. That is, the sixth NAT mapping can include: IP address of the first user plane network element + port number of the first control plane network element -> IP address of the first control plane network element. Refer to the relevant explanation of the second NAT mapping described above; it will not be repeated here.

[0519] For details on the third and fourth NAT mapping relationships, please refer to the relevant explanations regarding the third and fourth NAT mapping relationships in step S810 above, which will not be repeated here.

[0520] S1910, the first user plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the routing information of the second control plane network element and the routing information of the second user plane network element.

[0521] As one possible implementation, the first user plane network element can send the fifth NAT mapping relationship and the third NAT mapping relationship to the first control plane network element. The fifth NAT mapping relationship carries the routing information of the second control plane network element, and the third NAT mapping relationship carries the routing information of the second user plane network element.

[0522] Optionally, the first user plane network element can also send the sixth NAT mapping relationship and the fourth NAT mapping relationship to the first control plane network element.

[0523] As one possible implementation, the above steps S1909-S1910 can be understood as an implementation of the first control plane network element obtaining the routing information of the second control plane network element and the second user plane network element.

[0524] S1911, the first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0525] The implementation of step S1911 is similar to that of step S812 above. The only difference is that the IP address of the first control plane network element in step S812 is replaced with the IP address of the first user plane network element, the first NAT mapping relationship is replaced with the fifth NAT mapping relationship, and the second NAT mapping relationship is replaced with the sixth NAT mapping relationship. Refer to the relevant explanation of step S812 above; it will not be repeated here.

[0526] Optionally, after step S1911, the access network element may also send a service response message to the first terminal. Refer to the foregoing explanation of the service response message; further details will not be repeated here.

[0527] In one possible implementation, in this embodiment, a fifth connection is established between the first user plane network element and the second control plane network element, and a sixth connection is established between the first user plane network element and the second user plane network element. A seventh connection and an eighth connection are established between the access network element and the first user plane network element, with the seventh connection corresponding to the fifth connection and the eighth connection corresponding to the sixth connection. The seventh connection and the eighth connection can be the same connection or different connections.

[0528] As one possible implementation, the fifth and sixth connections can be established before or after the first user plane network element allocates routing information to the second control plane network element and the second user plane network element, or they can be established during the process of the first user plane network element allocating routing information, or before or after the first user plane network element sends the routing information to the first control plane network element, or they can be established during the process of the first user plane network element sending the routing information to the first control plane network element. This application does not impose specific limitations on the order of allocating / sending routing information and establishing the fifth and sixth connections; there is no dependency between them, and they can be decoupled and executed independently.

[0529] As one possible implementation, the fifth connection can be terminal-level, service-level, or task-level. For example, the first user plane network element and the second control plane network element can establish different fifth connections for different terminals, or establish different fifth connections for different services of the same terminal, or establish different fifth connections for different tasks of the same service of the same terminal.

[0530] For example, the identifier of the fifth connection can be a single identifier, such as connection identifier 5. For instance, the fifth connection can be an N4 connection, in which case connection identifier 5 can be N4 Id; or, the identifier of the fifth connection can include two parts, such as third identifier 1 and third identifier 2. Refer to the relevant descriptions of first identifier 1 and first identifier 2 above, which will not be repeated here. The establishment of the fifth connection can be initiated by the first user plane network element, or it can be initiated by the second control plane network element, without limitation.

[0531] As one possible implementation, the sixth connection can be terminal-level, service-level, or task-level. For example, the identifier of the sixth connection can be a single, unified identifier, such as connection identifier 6; or, the identifier of the sixth connection can include fourth identifier 1 and fourth identifier 2. Fourth identifier 1 can be assigned to a first user plane network element to identify the endpoint of the sixth connection on the first user plane network element side; fourth identifier 2 can be assigned to a second user plane network element to identify the endpoint of the sixth connection on the second user plane network element side. Fourth identifier 1 and fourth identifier 2 can be associated with the first terminal. Refer to the above description related to the second connection; further details are omitted here.

[0532] As one possible implementation, the seventh or eighth connection can be a GTP tunnel. The identifier for the seventh or eighth connection can be found in the description of the identifier for the fourth connection mentioned above, and will not be repeated here.

[0533] For example, the seventh or eighth connection can be identified by the TEID associated with the first terminal. For example, the seventh connection is denoted as TEID 1 and the eighth connection as TEID 2.

[0534] For example, TEID 1 may include TEID 11 and TEID 12. TEID 11 can be used to identify the endpoint of the seventh connection on the access network element side, and TEID 12 can be used to identify the endpoint of the seventh connection on the first user plane network element side. TEID 2 may include TEID 21 and TEID 22. TEID 21 can be used to identify the endpoint of the eighth connection on the access network element side, and TEID 22 can be used to identify the endpoint of the eighth connection on the first user plane network element side.

[0535] Understandably, when the seventh and eighth connections are the same connection, TEID 1 and TEID 2 are the same, TEID 11 and TEID 21 are the same, and TEID 12 and TEID 22 are the same.

[0536] Steps S1901-S1911 described above can be understood as the initial establishment or initial configuration phase. After step S1911, signaling / data transmission for the second network can proceed. For example, after step S1911, the method further includes the following steps:

[0537] S1912, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0538] The network indication information is used to indicate whether the first information is from a first network or a second network. The first information is signaling or data. Refer to the relevant explanation in step S705 above.

[0539] As one possible implementation, after receiving the first information and the network indication information, the access network element can determine whether the first information is from the first network or the second network based on the network indication information. Furthermore, the access network element can identify whether the first information is signaling or data, and thus can look up the routing information of the second control plane network element or the second user plane network element from the routing mapping table based on the network indication information. Refer to the relevant explanation in step S706a above; it will not be repeated here.

[0540] Specifically, if the first information is a first signaling message and the network indication information indicates that the first information is information of the second network, then steps S1913a-S1914a are executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then steps S1913b-S1914b are executed; if the first information is a first signaling message and the network indication information indicates that the first information is information of the first network, then step S1913c is executed; and if the first information is first data and the network indication information indicates that the first information is information of the second network, then step S1913d is executed.

[0541] S1913a, The access network element sends a first message to the first user plane network element. Correspondingly, the first user plane network element receives the first message from the access network element.

[0542] The first message includes a first signaling message and routing information for the first signaling message. The routing information for the first signaling message is used to route the first signaling message to the second control plane network element.

[0543] As one possible implementation, the routing information for the first signaling is determined based on the routing information of the second control plane network element. For example, if the routing information for the second control plane network element is its port number, the routing information for the first signaling indicates that the destination port number of the first signaling / first message is the port number of the second control plane network element. Furthermore, the destination IP address in the first message is the IP address of the first user plane network element, which may be the destination IP address returned by the first control plane network element to the access network element in step S1911.

[0544] As one possible implementation, the access network element sends the first message to the first user plane network element through the seventh connection. The first message may also include first indication information, which indicates that the first signaling is signaling associated with the first terminal. For example, the first indication information may include the inner IP address of the first terminal, the identifier of the seventh connection (such as TEID 1), the SUPI of the first terminal, TMSI, etc.

[0545] Optionally, if the first indication information includes the identifier of the seventh connection, the first indication information may also include the identifier of the access network element. Refer to the relevant explanation in step S814a above; it will not be repeated here.

[0546] S1914a: Based on the routing information of the first signaling, the first user plane network element determines to send the first signaling to the second control plane network element, and the first user plane network element sends a third message to the second control plane network element. Correspondingly, the second control plane network element receives the third message from the first user plane network element. The third message includes the first signaling.

[0547] As one possible implementation, after receiving the first message, the first user plane network element sends the first signaling to the second control plane network element if the routing information of the first signaling matches the routing information of the second control plane network element. For example, if the routing information of the second control plane network element is its port number, matching the routing information of the first signaling with the routing information of the second control plane network element can include: the routing information of the first signaling indicating that the destination port number of the first signaling is the port number of the second control plane network element.

[0548] As one possible implementation, the first user plane network element can send a third message to the second control plane network element based on the fifth NAT mapping relationship. For example, the first user plane network element can perform NAT translation based on the fifth NAT mapping relationship to obtain the third message, and then send the third message to the second control plane network element.

[0549] As one possible implementation, the first user plane network element sends the third message to the second control plane network element via the fifth connection. The third message may also include third indication information, which indicates that the first signaling is signaling associated with the first terminal. For example, the third indication information may include the inner IP address of the first terminal, the identifier of the fifth connection, the SUPI of the first terminal, etc. Optionally, if the third indication information includes the identifier of the fifth connection, the third indication information may also include the identifier of the access network element.

[0550] The implementation of step S1914a can be understood by referring to the relevant description in step S815a above. The first NAT mapping relationship in step S815a can be replaced with the fifth NAT mapping relationship, and the first control plane network element can be replaced with the first user plane network element. It will not be elaborated here.

[0551] S1913b: The access network element sends a second message to the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element.

[0552] The second message includes first data and routing information for the first data, the routing information of which is used to route the first data to the second user plane network element.

[0553] As one possible implementation, the routing information for the first data is determined based on the routing information of the second user plane network element. For example, if the routing information for the second user plane network element is its port number, the routing information for the first data indicates that the destination port number for the first data / second message is the port number of the second user plane network element. Furthermore, the destination IP address in the second message is the IP address of the first user plane network element, which may be the one returned by the first control plane network element to the access network element in step S1911.

[0554] As one possible implementation, the access network element sends the second message to the first user plane network element through the eighth connection. The second message may also include second indication information, which indicates that the first data is data associated with the first terminal. For example, the second indication information may include the inner IP address of the first terminal, the identifier of the eighth connection (such as TEID 2), the SUPI of the first terminal, TMSI, etc.

[0555] Optionally, if the second indication information includes the identifier of the eighth connection, the second indication information may also include the identifier of the access network element. Refer to the relevant explanation in step S814a above; it will not be repeated here.

[0556] S1914b: Based on the routing information of the first data, the first user plane network element determines to send the first data to the second user plane network element, and the first user plane network element sends a fourth message to the second user plane network element. Correspondingly, the second user plane network element receives the fourth message from the first user plane network element. The fourth message includes the first data.

[0557] As one possible implementation, after receiving the second message, the first user plane network element sends the first data to the second user plane network element if the routing information of the first data matches the routing information of the second user plane network element. For example, if the routing information of the second user plane network element is its port number, matching the routing information of the first data with the routing information of the second user plane network element can include: the routing information of the first data indicating that the destination port number of the first data is the port number of the second user plane network element.

[0558] As one possible implementation, the first user plane network element can perform NAT translation based on the third NAT mapping relationship to obtain the fourth message, and then send the fourth message to the second user plane network element.

[0559] As one possible implementation, the first user plane network element sends the fourth message to the second user plane network element through the sixth connection. The fourth message may further include fourth indication information, which indicates that the first data is data associated with the first terminal. For example, the fourth indication information may include the inner IP address of the first terminal, the identifier of the sixth connection, the SUPI and TMSI of the first terminal, etc. Optionally, if the fourth indication information includes the identifier of the sixth connection, the fourth indication information may also include the identifier of the access network element.

[0560] The implementation of step S1914b can be referred to the relevant description in step S815b above. The first control plane network element in step S815b can be replaced with the first user plane network element for understanding. It will not be repeated here.

[0561] S1913c, The access network element sends a first message to the first control plane network element based on the routing information of the first control plane network element. Correspondingly, the first control plane network element receives the first message from the access network element. Refer to the relevant explanation in step S814c above; it will not be repeated here.

[0562] As one possible implementation, if there is no communication interface or direct connection between the access network element and the first control plane element, step S1913c can be replaced by: the access network element sending the first message to the first user plane element; after receiving the first message, the first user plane element forwarding the first signaling to the first control plane element according to the destination port number (i.e., the port number of the first control plane element).

[0563] S1913d, The access network element sends a second message to the first user plane network element based on the routing information of the first user plane network element. Correspondingly, the first user plane network element receives the second message from the access network element. Refer to the relevant explanation in step S814d above; it will not be repeated here.

[0564] In one possible implementation, the communication method shown in FIG19 further includes step S1900 (not shown in the figure). The implementation of step S1900 is the same as that of step S700, and can be referred to the relevant description of S700 above, which will not be repeated here.

[0565] Based on the above description, when an access network element receives first information from a first terminal, and this first information is information from the second network or data from the first network, the access network element sends the first information to the first user plane network element. Further, when the first information is signaling from the second network, the access network element sets the destination port of the message carrying the signaling to the port of the second control plane network element (e.g., port2); when the first information is data from the second network, the access network element sets the destination port of the message carrying the data to the port of the second user plane network element (e.g., port2'); when the first information is data from the first network, the access network element sets the destination port of the message carrying the data to the port of the first user plane network element (e.g., port1'). After receiving the first information, the first user plane network element can distinguish whether the message carries signaling or data from the second network based on the destination port, and then forward the signaling or data to the corresponding second control plane network element or second user plane network element.

[0566] Furthermore, in the presence of multiple second networks, the first user plane network element can assign different port numbers to the control plane network elements in different second networks, and assign different port numbers to the user plane network elements in different second networks. Please refer to the relevant explanations in the process shown in Figure 8 above, which will not be repeated here.

[0567] The routing of uplink signaling / data has been explained above. For downlink signaling, the second control plane network element sends downlink signaling to the first user plane network element. The first user plane network element performs NAT translation based on the routing information (or the fifth NAT mapping relationship) of the second control plane network element and then sends the downlink signaling to the access network element. For downlink data, the second user plane network element sends downlink data to the first user plane network element. The first user plane network element performs NAT translation based on the routing information (or the third NAT mapping relationship) of the second user plane network element and then sends the downlink data to the access network element. Refer to the relevant explanations in the process shown in Figure 8 above; they will not be repeated here.

[0568] The flowchart shown in Figure 19 uses port numbers as an example to illustrate the process, with the routing information of the second control plane network element and the second user plane network element serving as the example. Furthermore, in one possible implementation, the routing information of the second control plane network element can be replaced with the IP address associated with the second control plane network element, and the routing information of the second user plane network element can be replaced with the IP address associated with the second user plane network element. Referring to the relevant explanations in the flowchart shown in Figure 8, the first control plane network element can be replaced with the first user plane network element for clarification; further details will not be elaborated upon here.

[0569] In another possible implementation, the routing information of the second control plane network element can be the IP address and port number associated with the second control plane network element. The routing information of the second user plane network element can be the IP address and port number associated with the second user plane network element. Referring to the relevant descriptions in the flowchart shown in Figure 8, the first control plane network element can be replaced with the first user plane network element for understanding; further details will not be elaborated here.

[0570] In the above scheme, when the access network element sends information to the first user plane network element, it distinguishes whether the information is intended for the first network or the second network using different ports and / or IP addresses. It can also distinguish whether the information is signaling or data destined for the second network using different ports and / or IP addresses. This allows the first user plane network element to determine whether local processing or forwarding is required based on the port and / or IP address. If signaling needs to be forwarded, it can further perform corresponding routing based on the port and / or IP address. This enables signaling / data transmission between the access network element and the second network, supports the separation of the second network's core network elements from the first network, and thus meets various user needs of the second network, such as fulfilling increasingly higher mobility requirements and improving user experience.

[0571] In the fifth possible implementation scenario, in scenario two above, where the routing information of the second control plane network element is the identifier of the second control plane network element, and the routing information of the second user plane network element is the identifier of the second user plane network element, the communication process provided in this application can be as shown in Figure 20. Referring to Figure 20, this communication process may include the following steps:

[0572] S2001-S2003 are the same as steps S801-S803 above. Please refer to the relevant explanations of steps S801-S803 above. They will not be repeated here.

[0573] S2004-S2008 are the same as steps S805-S809 above. Please refer to the relevant explanations of steps S805-S809 above. They will not be repeated here.

[0574] S2009, the first control plane network element sends a second request message to the first user plane network element. Correspondingly, the first user plane network element receives the second request message from the first control plane network element.

[0575] The second request information is used to request routing information from the second control plane network element and the second user plane network element. For example, the second request message may include the IP addresses of the second control plane network element and the second user plane network element.

[0576] As one possible implementation, after receiving the second request information, the first user plane network element can allocate routing information to the second control plane network element and the second user plane network element. The routing information for the second control plane network element is its identifier, and the routing information for the second user plane network element is its identifier. The implementation of the first user plane network element allocating routing information to the second control plane network element can refer to the implementation of the first control plane network element in step S904 above, and the implementation of the first user plane network element allocating routing information to the second user plane network element can refer to the implementation of the first user plane network element in step S910 above, and will not be repeated here.

[0577] For example, the identifier of the second control plane network element and the identifier of the second user plane network element can be the same or different. If they are the same, the subsequent access network element can send additional indication information to indicate whether signaling or data is being sent to the first user plane network element. The following embodiments of this application illustrate this using the example of different identifiers.

[0578] As one possible implementation, the first user plane network element can establish a fifth identifier mapping relationship and a third identifier mapping relationship. Optionally, the first user plane network element can also establish a sixth identifier mapping relationship and a fourth identifier mapping relationship.

[0579] The fifth identifier mapping relationship is similar to the first identifier mapping relationship described above, except that the IP address of the first control plane network element in the first identifier mapping relationship is replaced with the IP address of the first user plane network element. That is, the fifth identifier mapping relationship can include: IP address of the first user plane network element + identifier of the second control plane network element -> IP address of the second control plane network element. For example, it can be represented as IP address of UPF1 + id 2 -> IP address of MM2. Refer to the relevant explanation of the first NAT mapping relationship above; further details are omitted here.

[0580] The sixth identifier mapping relationship is similar to the second identifier mapping relationship described above. Simply replace the IP address of the first control plane network element in the second identifier mapping relationship with the IP address of the first user plane network element. That is, the sixth identifier mapping relationship can include: IP address of the first user plane network element + identifier of the first control plane network element -> IP address of the first control plane network element. Refer to the relevant explanation of the second identifier mapping relationship above; it will not be repeated here.

[0581] The third and fourth identifier mapping relationships can be found in the relevant explanations regarding the third and fourth identifier mapping relationships in step S910 above, and will not be repeated here.

[0582] S2010, the first user plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the first control plane network element. Correspondingly, the first control plane network element receives the routing information of the second control plane network element and the routing information of the second user plane network element.

[0583] As one possible implementation, the first user plane network element can send a fifth identifier mapping relationship and a third identifier mapping relationship to the first control plane network element. The fifth identifier mapping relationship carries the routing information of the second control plane network element, and the third identifier mapping relationship carries the routing information of the second user plane network element.

[0584] Optionally, the first user plane network element can also send the sixth identifier mapping relationship and the fourth identifier mapping relationship to the first control plane network element.

[0585] In steps S2009-S2010 above, the example of the first user plane network element allocating routing information to the second control plane network element and the second user plane network element is used for illustration. In another possible implementation, the routing information of the second control plane network element and the second user plane network element can also be allocated by the first control plane network element. In this case, step S2009 above can be replaced by: the first control plane network element allocating routing information to the second control plane network element and the second user plane network element, such as allocating the identifier of the second control plane network element and the identifier of the second user plane network element. The implementation of the first control plane network element can refer to the implementation of the first user plane network element in step S2009, and will not be repeated here. In addition, step S2010 above can be replaced by: the first control plane network element sending the routing information of the second control plane network element and the routing information of the second user plane network element to the first user plane network element, such as sending the fifth identifier mapping relationship and the third identifier mapping relationship to the first user plane network element. Furthermore, the sixth identifier mapping relationship and the fourth identifier mapping relationship can also be sent.

[0586] As one possible implementation, the above steps S2009-S2010 can be understood as an implementation of the first control plane network element obtaining the routing information of the second control plane network element and the second user plane network element.

[0587] S2011, the first control plane network element sends routing information of the second control plane network element and routing information of the second user plane network element to the access network element. Correspondingly, the access network element receives the routing information of the second control plane network element and the second user plane network element from the first control plane network element.

[0588] The implementation of step S2011 is similar to that of step S812 above. In step S812, the IP address of the first control plane network element can be replaced with the IP address of the first user plane network element, the first identifier mapping relationship can be replaced with the fifth identifier mapping relationship, and the second identifier mapping relationship can be replaced with the sixth identifier mapping relationship. The routing information of the second control plane network element can be replaced with the identifier of the second control plane network element, and the routing information of the second user plane network element can be replaced with the identifier of the second user plane network element. Refer to the relevant explanation of step S812 above; it will not be repeated here.

[0589] Optionally, after step S2011, the access network element may also send a service response message to the first terminal. Refer to the foregoing explanation of the service response message; further details will not be repeated here.

[0590] As one possible implementation, in this embodiment, a fifth connection is established between the first user plane network element and the second control plane network element, and a sixth connection is established between the first user plane network element and the second user plane network element. A seventh connection and an eighth connection are established between the access network element and the first user plane network element, with the seventh connection corresponding to the fifth connection and the eighth connection corresponding to the sixth connection. The seventh connection and the eighth connection can be the same connection or different connections. Refer to the relevant descriptions in the flowchart shown in Figure 19; they will not be repeated here.

[0591] Steps S2001-S2011 described above can be understood as the initial establishment or initial configuration phase. After step S2011, signaling / data transmission of the second network can proceed. For example, after step S2011, the method further includes the following steps:

[0592] S2012, the first terminal sends first information and network indication information to the access network element. Correspondingly, the access network element receives the first information and network indication information from the first terminal.

[0593] The network indication information is used to indicate whether the first information is from a first network or a second network. The first information is signaling or data. Refer to the relevant explanation in step S705 above.

[0594] As one possible implementation, after receiving the first information and the network indication information, the access network element can determine whether the first information is from the first network or the second network based on the network indication information. Furthermore, the access network element can identify whether the first information is signaling or data, and thus can look up the routing information of the second control plane network element or the second user plane network element from the routing mapping table based on the network indication information. Refer to the relevant explanation in step S706a above; it will not be repeated here.

[0595] Specifically, if the first information is a first signaling message and the network indication information indicates that the first information is information of the second network, then the following steps S2013a-S2014a are executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then the following steps S2013b-S2014b are executed; if the first information is a first signaling message and the network indication information indicates that the first information is information of the first network, then the following step S2013c is executed; if the first information is first data and the network indication information indicates that the first information is information of the second network, then the following step S2013d is executed.

[0596] S2013a, The access network element sends a first message to the first user plane network element. Correspondingly, the first user plane network element receives the first message from the access network element.

[0597] The first message includes a first signaling message and routing information for the first signaling message. The routing information for the first signaling message is used to route the first signaling message to the second control plane network element.

[0598] As one possible implementation, the routing information of the first signaling is determined based on the routing information of the second control plane network element. For example, if the routing information of the second control plane network element is its identifier, then the routing information of the first signaling includes the routing information of the second control plane network element; that is, the routing information of the first signaling includes the identifier of the second control plane network element. In other words, the first message may include both the first signaling and the identifier of the second control plane network element.

[0599] Optionally, the routing information of the first signaling may also include the identifier of the access network element, as can be found in the relevant description in step S914a above, and will not be repeated here.

[0600] As one possible implementation, the first signaling can be encapsulated in the first protocol layer, for example, in a container of the first protocol layer. The identifiers of the second control plane network element and the identifiers of the access network element (optional) can be carried in the second protocol layer, as described in the relevant explanation in step S914 above, and will not be repeated here.

[0601] As one possible implementation, the destination IP address of the first message is the IP address of the first user plane network element.

[0602] As one possible implementation, the access network element sends the first message to the first user plane network element through the seventh connection. The first message may also include first indication information, which indicates that the first signaling is signaling associated with the first terminal. Refer to the relevant description in step S1913a above; it will not be repeated here.

[0603] S2014a: The first user plane network element determines, based on the routing information of the first signaling, to send the first signaling to the second control plane network element, and the first user plane network element sends a third message to the second control plane network element. Correspondingly, the second control plane network element receives the third message from the first user plane network element. The third message includes the first signaling.

[0604] As one possible implementation, after receiving the first message, the first user plane network element sends the first signaling to the second control plane network element if the routing information of the first signaling matches the routing information of the second control plane network element. For example, if the routing information of the second control plane network element is its identifier, matching the routing information of the first signaling with the routing information of the second control plane network element may include the routing information of the first signaling including the identifier of the second control plane network element. Refer to the...

Claims

1. A communication method, characterized in that, The method is applied to a first control plane network element, which is deployed in a first network. The method includes: Receive a service request message from an access network element, the service request message being used to request access to a service in the second network; According to the service request message, the routing information of the second control plane network element and the routing information of the second user plane network element are obtained. The second control plane network element and the second user plane network element are deployed in the second network. The routing information of the second control plane network element and the routing information of the second user plane network element are sent to the access network element.

2. The method according to claim 1, characterized in that, The step of obtaining the routing information of the second control plane network element and the routing information of the second user plane network element includes: Assign routing information for the second control plane network element; Send a first request message to a first user plane network element, the first request message being used to request routing information from a second user plane network element, the first user plane network element being deployed in the first network; Receive routing information from the second user plane network element of the first user plane network element.

3. The method according to claim 2, characterized in that, The method further includes: establishing a first connection, wherein the first connection is a connection between the first control plane network element and the second control plane network element; The connection between the access network element and the second control plane element includes the first connection and the third connection, wherein the third connection is the connection between the access network element and the first control plane element; The routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, or includes the identifier of the connection between the access network element and the second control plane network element.

4. The method according to claim 2 or 3, characterized in that, The routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, or includes the identifier of the connection between the access network element and the second user plane network element; Wherein, the second connection is the connection between the first user plane network element and the second user plane network element, and the fourth connection is the connection between the access network element and the first user plane network element. The connection between the access network element and the second user plane network element includes the second connection and the fourth connection.

5. The method according to claim 1, characterized in that, The step of obtaining the routing information of the second control plane network element and the routing information of the second user plane network element includes: Assign routing information for the second control plane network element to the second control plane network element, and assign routing information for the second user plane network element to the second user plane network element.

6. The method according to claim 5, characterized in that, The method further includes: The routing information of the second user plane network element is sent to the first user plane network element, where the first user plane network element is deployed in the first network.

7. The method according to claim 5, characterized in that, The method further includes: The routing information of the second control plane network element and the routing information of the second user plane network element are sent to the first user plane network element, wherein the first user plane network element is deployed in the first network.

8. The method according to claim 1, characterized in that, The step of obtaining the routing information of the second control plane network element and the routing information of the second user plane network element includes: Send a second request message to the first user plane network element. The second request message is used to request the routing information of the second control plane network element and the routing information of the second user plane network element. The first user plane network element is deployed in the first network. The system receives routing information from the second control plane network element and routing information from the second user plane network element.

9. The method according to claim 8, characterized in that, The routing information of the second control plane network element includes the identifiers of the fifth connection and the seventh connection, or includes the identifier of the connection between the access network element and the second control plane network element; The fifth connection is the connection between the first user plane network element and the second control plane network element, and the seventh connection is the connection between the access network element and the first user plane network element. The connection between the access network element and the second control plane network element includes the fifth connection and the seventh connection.

10. The method according to claim 8 or 9, characterized in that, The routing information of the second user plane network element includes the identifiers of the sixth connection and the eighth connection, or includes the identifier of the connection between the access network element and the second user plane network element; The sixth connection is the connection between the first user plane network element and the second user plane network element, and the eighth connection is the connection between the access network element and the first user plane network element. The connection between the access network element and the second user plane network element includes the sixth connection and the eighth connection.

11. The method according to any one of claims 1-6, characterized in that, The method further includes: Receive signaling from the access network element and routing information of the signaling, wherein the routing information of the signaling is used to route the signaling to the second control plane element; Based on the routing information of the signaling, it is determined to send the signaling to the second control plane network element.

12. The method according to claim 11, characterized in that, When the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, the signaling is determined to be sent to the second control plane network element based on the routing information of the signaling, including: If the routing information of the signaling includes the identifier of the third connection, or if it includes both the identifier of the first connection and the identifier of the third connection, then the signaling is determined to be sent to the second control plane network element.

13. The method according to claim 12, characterized in that, The step of receiving signaling and routing information of the signaling from the access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, and the source IP address of the first message being the IP address of the access network element; The method further includes: sending a third message to the second control plane network element according to the first connection mapping relationship, wherein the third message includes the signaling; wherein... The first connection mapping relationship includes the IP address of the access network element and the identifier of the third connection, and the mapping relationship between the identifier of the first connection and the IP address of the second control plane network element. The destination IP address of the third message is the IP address of the second control plane network element.

14. The method according to claim 11, characterized in that, When the routing information of the second control plane network element includes the port number of the second control plane network element, the signaling is determined to be sent to the second control plane network element based on the routing information of the signaling, including: If the routing information of the signaling indicates that the destination port number of the signaling is the port number of the second control plane network element, then it is determined that the signaling will be sent to the second control plane network element.

15. The method according to claim 14, characterized in that, The step of receiving signaling and routing information of the signaling from the access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, and the destination IP address of the first message being the IP address of the first control plane element. The method further includes: sending a third message to the second control plane network element according to the first Network Address Translation (NAT) mapping relationship, wherein the third message includes the signaling; The first NAT mapping relationship includes the mapping relationship between the IP address of the first control plane network element and the port number of the second control plane network element, and the IP address of the second control plane network element. The destination IP address of the third message is the IP address of the second control plane network element.

16. The method according to claim 11, characterized in that, When the routing information of the second control plane network element includes the identifier of the second control plane network element, determining to send the signaling to the second control plane network element based on the routing information of the signaling includes: If the routing information of the signaling includes the identifier of the second control plane network element, it is determined that the signaling should be sent to the second control plane network element.

17. The method according to claim 16, characterized in that, The step of receiving signaling and routing information of the signaling from the access network element includes: receiving a first message from the access network element, the first message including the signaling and routing information of the signaling, and the destination IP address of the first message being the IP address of the first control plane element. The method further includes: sending a third message to the second control plane network element according to the first identifier mapping relationship, wherein the third message includes the signaling; The first identifier mapping relationship includes the mapping relationship between the IP address of the first control plane network element and the identifier of the second control plane network element, and the IP address of the second control plane network element. The destination IP address of the third message is the IP address of the second control plane network element.

18. A communication method, characterized in that, The method is applied to an access network element, and the method includes: Receive first information and network indication information from a first terminal, wherein the network indication information is used to indicate that the first information is to be sent to a second network; If the first information is signaling, the signaling and its routing information are sent to the first control plane network element or the first user plane network element, wherein the routing information is used to route the signaling to the second control plane network element; or, When the first information is data, the data and the routing information of the data are sent to the first user plane network element, and the routing information of the data is used to route the data to the second user plane network element; The first control plane network element and the first user plane network element are deployed in the first network, and the second control plane network element and the second user plane network element are deployed in the second network.

19. The method according to claim 18, characterized in that, Before receiving the first information and network indication information from the first terminal, the method further includes: Receive a service request message from the first terminal, the service request message being used to request access to a service in the second network; Send the service request message to the first control plane network element; The system receives routing information from the first control plane network element, the second control plane network element, and the second user plane network element. The routing information from the second control plane network element is used to determine the routing information of the signaling, and the routing information from the second user plane network element is used to determine the routing information of the data. A service response message is sent to the first terminal, the service response message being used to indicate permission to access services in the second network.

20. The method according to claim 19, characterized in that, When the routing information of the second control plane network element includes the identifier of the first connection and the identifier of the third connection, the routing information of the signaling includes the identifier of the third connection, or includes the identifier of the third connection and the identifier of the first connection; Wherein, the first connection is the connection between the first control plane network element and the second control plane network element, the third connection is the connection between the access network element and the first control plane network element, and the connection between the access network element and the second control plane network element includes the first connection and the third connection.

21. The method according to claim 19, characterized in that, When the routing information of the second control plane network element includes the identifier of the fifth connection and the identifier of the seventh connection, the routing information of the signaling includes the identifier of the seventh connection, or includes the identifier of the seventh connection and the identifier of the fifth connection; The fifth connection is the connection between the first user plane network element and the second control plane network element, and the seventh connection is the connection between the access network element and the first user plane network element. The connection between the access network element and the second control plane network element includes the fifth connection and the seventh connection.

22. The method according to claim 19, characterized in that, When the routing information of the second control plane network element includes the port number of the second control plane network element, the routing information of the signaling indicates that the destination port number of the signaling is the port number of the second control plane network element.

23. The method according to claim 19, characterized in that, When the routing information of the second control plane network element includes the identifier of the second control plane network element, the routing information of the signaling includes the identifier of the second control plane network element.

24. The method according to claim 19, characterized in that, When the routing information of the second user plane network element includes the identifier of the second connection and the identifier of the fourth connection, the routing information of the data includes the identifier of the fourth connection, or includes the identifier of the fourth connection and the identifier of the second connection; Wherein, the second connection is the connection between the first user plane network element and the second user plane network element, and the fourth connection is the connection between the access network element and the first user plane network element. The connection between the access network element and the second user plane network element includes the second connection and the fourth connection.

25. The method according to claim 19, characterized in that, When the routing information of the second user plane network element includes the port number of the second user plane network element, the routing information of the data indicates that the destination port number of the data is the port number of the second user plane network element.

26. The method according to claim 19, characterized in that, When the routing information of the second user plane network element includes the identifier of the second user plane network element, the routing information of the data includes the identifier of the second user plane network element.

27. The method according to any one of claims 18-26, characterized in that, The method further includes: searching for routing information of the second control plane network element and / or routing information of the second user plane network element according to the network indication information, wherein the routing information of the second control plane network element is used to determine the routing information of the signaling, and the routing information of the second user plane network element is used to determine the routing information of the data.

28. The method according to claim 27, characterized in that, When the network indication information includes the terminal identifier of the first terminal in the second network, the routing information of the second control plane network element and / or the routing information of the second user plane network element is looked up in the first routing mapping table. The first routing mapping table includes the terminal identifier of the first terminal in the second network and the mapping relationship between it and the routing information of the second control plane network element and / or the routing information of the second user plane network element. or, If the network indication information includes the identifier of the second service, the routing information of the second control plane network element and / or the routing information of the second user plane network element is looked up in the second routing mapping table. The second routing mapping table includes the identifier of the second service and the mapping relationship between it and the routing information of the second control plane network element and / or the routing information of the second user plane network element.

29. A communication method, characterized in that, The method is applied to a first terminal, and the method includes: Generate first information, wherein the first information is either control signaling for the service or service data for the service; Send the first information and network indication information to the access network element; Wherein, if the service is a first service in a first network, the network indication information is used to indicate that the first information is to be sent to the first network; or, if the service is a second service in a second network, the network indication information is used to indicate that the first information is to be sent to the second network.

30. The method according to claim 29, characterized in that, When the service is a second service in a second network, the network indication information includes at least one of the following: The identifier of the second network, the terminal identifier of the first terminal in the second network, the IP address of the first terminal in the second network, the identifier of the second service, the routing information of the second control plane network element, or the routing information of the second user plane network element; wherein the second control plane network element and the second user plane network element are deployed in the second network.

31. The method according to claim 29 or 30, characterized in that, The method further includes: determining, based on the mapping relationship between services and networks, whether the service is a first service in the first network or a second service in the second network.

32. The method according to claim 31, characterized in that, If the service is determined to be a second service in the second network, the method further includes: Send a service request message to the access network element, the service request message being used to request access to a service in the second network; Receive a service response message from an access network element, the response message indicating permission to access services in the second network.

33. A communication device, characterized in that, The communication device includes a processor; the processor is configured to run a computer program or instructions to cause the communication device to perform the method as claimed in any one of claims 1-17, or to cause the communication device to perform the method as claimed in any one of claims 18-28, or to cause the communication device to perform the method as claimed in any one of claims 29-32.

34. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions or programs that, when executed on a computer, cause the method as described in any one of claims 1-17 to be performed, or cause the method as described in any one of claims 18-28 to be performed, or cause the method as described in any one of claims 29-32 to be performed.

35. A computer program product, characterized in that, The computer program product includes computer instructions; when some or all of the computer instructions are executed on a computer, they cause the method of any one of claims 1-17 to be performed, or cause the method of any one of claims 18-28 to be performed, or cause the method of any one of claims 29-32 to be performed.

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