Communication method and communication apparatus

Abstract

The present application provides a communication method and a communication apparatus, which are used for solving the problem of it not being possible for a user equipment (UE) to access the same network by means of two different 3rd generation partnership project (3GPP) paths at the same time. The method comprises: when a UE accesses a network by means of a first path that connects a first radio access network device with a first access and mobility management network element, the UE sends to a second access network device indication information that indicates the selection of a different access and mobility management network element. Thus, on the basis of identification information of the first access and mobility management network element and the indication information, the second access network device can select a second access and mobility management network element different from the first access and mobility management network element, so as to complete the registration of the UE in a second path, such that the UE can access the same network by means of different paths of the two different access and mobility management network elements.

Description

Communication method and communication device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on November 30, 2023, with application number 202311636440.1 and invention name “Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of communications, and more specifically, to a communication method and a communication device. Background Art

[0004] Dual connection technology can be called Dual Steer technology. In a dual connection scenario, user equipment (UE) can access the same network through two third generation partnership project (3GPP) access type connections at the same time. For example, the UE can use a subscriber identity module (SIM) card to access the same public land mobile network (PLMN) through two different radio access networks (RAN) of 3GPP access type. The 3GPP access type corresponds to two paths, and both paths will pass through the access and mobility management function (AMF).

[0005] Currently, in a dual-connectivity scenario, two different RANs in two paths will select the same AMF to access the same network. However, when the AMF establishes the second path for the same UE, it will release the connection of the first path. Therefore, it is impossible to access the network through two different paths of 3GPP access type at the same time.

[0006] Therefore, how to enable the UE to access the same network through two different paths simultaneously in a dual connectivity scenario is an urgent problem to be solved. Summary of the Invention

[0007] The present application provides a communication method and a communication device, which enable a UE to access the same network through two different 3GPP paths at the same time, thereby improving the communication rate.

[0008] To achieve the above objectives, this application adopts the following technical solutions:

[0009] In a first aspect, a communication method is provided, which can be executed by a communication device.

[0010] The method includes: a communication device accesses a network through a first path connecting a first radio access network device and a first access and mobility management network element; the communication device sends a request message to a second radio access network device, the request message is used to request that the communication device be registered with the network, the request message includes indication information, the indication information is used by the second radio access network device to select a second access and mobility management network element different from the first access and mobility management network element, and the communication device accesses the network through the first path and the second path connecting the second radio access network device and the second access and mobility management network element at the same time.

[0011] It is understood that in the present application, the communication device described in the first aspect and the following aspects can be a terminal device (such as a mobile phone), or a chip (system) that can be set in the terminal device. In other words, the communication method described in the first aspect can be executed by the terminal device, or by the chip (system) in the terminal device.

[0012] In the communication method provided based on the first aspect, an indication information for selecting a different access and mobility management network element is sent to a second radio access network device through a communication device, so that the second radio access network device selects an access and mobility management network element different from that in the first path, so that the different access and mobility management network elements respectively maintain an N2 connection for the communication device, and then the communication device can access the same network through two different paths for two different access and mobility management network elements.

[0013] In one possible implementation, the indication information indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths connect two different radio access network devices and two different access and mobility management network elements, respectively. Alternatively, the indication information instructs selection of different access and mobility management network elements. By informing the second radio access network device that the communication device is accessing the network via dual connectivity, different access and mobility management network elements are selected for network access by the communication device.

[0014] In one possible implementation, the indication information is a Subscription Concealed Identifier (SUCI) of the communication device. It is understood that the SUCI may implicitly indicate that the communication device supports simultaneous network access via two different paths, or implicitly indicate that the communication device desires to simultaneously access the network via two different paths, or the SUCI may indicate selection of different access and mobility management network elements. Exemplarily, the request message may be an access network (AN) message, and the AN parameters in the AN message include the SUCI and identification information of the first access and mobility management network element. Therefore, the AN message received by the second radio access network device includes the SUCI and identification information of the first access and mobility management network element. The second radio access network device may determine, based on the identification information of the first access and mobility management network element, that the communication device is not performing initial registration but has sent the SUCI, and therefore may determine that the communication device desires to access the network via dual connectivity.

[0015] In one possible implementation, the request message is an access network (AN) message. The communication device sends the AN message to the second radio access network device. The AN message is used to request that the communication device be registered with the network. AN parameters in the AN message include indication information. Because the access network parameter is a field that the radio access network device can parse, the indication information is obtained.

[0016] In another possible implementation, the communication device sends an AN message to the second radio access network device. The AN message is used to request that the communication device be registered with the network. The AN message includes AN parameters, and the AN parameters include indication information and identification information of the first access and mobility management network element. By sending the indication information and the identification information of the first access and mobility management network element to the second radio access network device, the second radio access network device is informed of the selection of an access and mobility management network element other than the first access and mobility management network element.

[0017] In a possible implementation manner, the communication device receives a registration acceptance message from the first access and mobility management network element through a first path, where the registration acceptance message includes identification information of the first access and mobility management network element.

[0018] In one possible implementation, before the communication device sends a request message, the communication device determines that it wants to access the network through two different paths at the same time. The communication device further determines that it has already accessed the network through the first path, and therefore needs to register to the network through the second path, that is, the communication device sends the request message to the second wireless access network device.

[0019] In one possible implementation, a communication device receives first information indicating a radio access technology (RAT) type that the communication device is allowed to access a network. Based on the first information, the communication device selects a radio access network device corresponding to the RAT type allowed to access the network and registers with the network. The communication device obtains the RAT type allowed by the network and accesses the network using the allowed RAT type. The network notifies the communication device of the first information, so that the communication device selects an appropriate RAT type from the first information for access, thereby preventing the UE from selecting an inaccessible RAT and increasing the UE's access success rate.

[0020] In one possible implementation, the RAT type corresponding to the second radio access network device is included in the RAT types allowed to access the network. This can be understood as the communication device determining an appropriate RAT type based on the first information and thus selecting the second radio access network device of the appropriate RAT type.

[0021] In a second aspect, a communication method is provided, which can be executed by a communication device, or by a chip or circuit of the communication device, which is not limited in this application. For ease of description, the following description is based on an example of execution by a communication device.

[0022] The method includes: a communication device accesses a network through a first path connecting a first radio access network device and a first access and mobility management network element; the communication device sends a request message to a second access and mobility management network element through a second radio access network device, the request message is used to request that the communication device be registered with the network, the request message includes information used by the second access and mobility management network element to generate a context of the communication device that is different from the first path, the second access and mobility management network element is the same as or different from the first access and mobility management network element, and the communication device accesses the network through the first path and the second path connecting the second radio access network device and the second access and mobility management network element at the same time.

[0023] In the communication method provided based on the second aspect, information for generating a context of a communication device different from the first path for the access and mobility management network element is sent to the access and mobility management network element through the communication device, so that the access and mobility management network element creates a new communication device context for the communication device based on the information. Therefore, when the two paths use the same access and mobility management network element, the access and mobility management network element retains two N2 connections corresponding to the two paths through two sets of communication device contexts, and thus the communication device can access the same network through two different paths for the same access and mobility management network element.

[0024] In one possible implementation, a communication device sends a request message, which is a registration request message, to a second access and mobility management network element via a second radio access network device. The registration request message includes information used by the access and mobility management network element to generate a context for the communication device that is different from the first path. Because the registration request message contains a field that can be parsed by the second access and mobility management network element, the second access and mobility management network element obtains information used by the access and mobility management network element to generate a context for the communication device that is different from the first path. Furthermore, the second access and mobility management network element creates a new communication device context for the communication device. It should be noted that when the second access and mobility management network element is the same as the first access and mobility management network element on the first path, the second access and mobility management network element retains the communication device context for the first path and creates a communication device context for the second path. When the second access and mobility management network element is different from the first access and mobility management network element on the first path, the second access and mobility management network element may create a context for the communication device.

[0025] In one possible implementation, the information used by the access and mobility management network element to generate a context for a communication device that is different from the first path indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements. Alternatively, the information used by the access and mobility management network element to generate a context for a communication device that is different from the first path indicates creation of a context for the trusted device.

[0026] In one possible implementation, the information used by the access and mobility management network element to generate the context of a communication device that is different from the first path is SUCI, that is, the identifier of the communication device carried in the registration request message is SUCI. It can be understood that although the communication device here has a 5G globally unique temporary identity (5G-GUTI) assigned by the first access and mobility management network element, the identifier of the communication device used in the registration request message sent by the communication device is SUCI, and the registration type can be initial registration. Therefore, the second access and mobility management network element cannot associate the context of the communication device through the identification information of the communication device, that is, SUCI. The second access and mobility management network element will consider that the communication device is a different communication device from the communication device of the first path based on SUCI, and therefore will create a second communication device context for the communication device.

[0027] In one possible implementation, a communication device initially registers with a network via a first path using a first SUCI, and registers with the network via a second path using a second SUCI different from the first SUCI.

[0028] In another possible implementation, a communication device uses a first SUCI to non-initially register with the network via a first path, and uses a second SUCI different from the first SUCI to register with the network via a second path. It should be noted that when the communication device uses different SUCIs, the second access and mobility management network element considers the communication device and the communication device on the first path to be different communication devices based on the different SUCIs. It should be noted that the communication device may encrypt a subscriber permanent identifier (SUPI) to obtain a SUCI. The communication device may encrypt the same SUPI to obtain a different SUCI each time, for example, once encrypting the first SUCI and another time encrypting the second SUCI. The SUPIs obtained after subsequent decryption of the first SUCI and the second SUCI are the same.

[0029] In a possible implementation manner, before the communication apparatus sends the request message to the second radio access network device, the communication apparatus generates a second SUCI.

[0030] In one possible implementation, the communication device generates a second SUCI based on information that the communication device wants to access the network simultaneously through two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements.

[0031] In one possible implementation, before the communication device sends a request message, the communication device determines that it wants to access the network through two different paths at the same time. The communication device further determines that it has already accessed the network through the first path, and therefore needs to register to the network through the second path, that is, the communication device sends the request message to the second wireless access network device.

[0032] In one possible implementation, a communication device receives first information indicating a radio access technology (RAT) type that the communication device is allowed to access a network. Based on the first information, the communication device selects a radio access network device corresponding to the RAT type allowed to access the network and registers with the network. The communication device obtains the RAT type allowed by the network and accesses the network using the allowed RAT type. The network notifies the communication device of the first information, allowing the communication device to select an appropriate RAT type from the first information for access. This prevents the UE from selecting an inaccessible RAT and increases the UE's access success rate.

[0033] In one possible implementation, the RAT type corresponding to the second radio access network device is included in the RAT types allowed to access the network. This can be understood as the communication device determining an appropriate RAT type based on the first information and thus selecting the second radio access network device of the appropriate RAT type.

[0034] In a third aspect, a communication method is provided, which can be executed by a communication device, or by a chip or circuit of the communication device, which is not limited in this application. For ease of description, the following description is based on an example of execution by a communication device.

[0035] The method includes: a communication device accesses a network via a first path connecting a first radio access network device and a first access and mobility management network element; the communication device sends a request message to a second access and mobility management network element via a second radio access network device, the request message is used to request that the communication device be registered with the network, the request message includes indication information, the indication information is used to retain the connection of the first path when establishing a connection of the second path, the second access and mobility management network element is the same as or different from the first access and mobility management network element, and the communication device accesses the network via the first path and the second path connecting the second radio access network device and the second access and mobility management network element at the same time.

[0036] In the communication method provided in the third aspect, a communication device sends instruction information to an access and mobility management network element, indicating that the connection on the first path should be retained while establishing a connection on the second path. Based on this information, the access and mobility management network element retains the connection on the first path while establishing a connection on the second path for the communication device. Thus, when the two paths involve the same access and mobility management network element, the access and mobility management network element retains the connections on the two paths, respectively. Thus, the communication device can access the same network via two different paths directed to the same access and mobility management network element.

[0037] In one possible implementation, the indication information indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements. Alternatively, the indication information indicates that the connection via the first path is retained while establishing a connection via the second path.

[0038] In one possible implementation, the registration request message includes a registration type. The indication information is a field in the registration type. Exemplarily, the field in the registration type is DualSteer Registration, which can be understood as a new registration type. The name is not limited here. The registration type is DualSteer Registration, which is used to indicate that the registration is a second path for dual-connection registration for the communication device. That is, the value of the registration type field in the prior art is replaced by DualSteer Registration, thereby minimizing the changes to the existing request message format and ensuring the compatibility of the system.

[0039] In one possible implementation, before the communication device sends a request message, the communication device determines that it wants to access the network through two different paths at the same time. The communication device further determines that it has already accessed the network through the first path, and therefore needs to register to the network through the second path, that is, the communication device sends the request message to the second wireless access network device.

[0040] In one possible implementation, a communication device receives first information indicating a radio access technology (RAT) type that the communication device is allowed to access a network. Based on the first information, the communication device selects a radio access network device corresponding to the RAT type allowed to access the network and registers with the network. The communication device obtains the RAT type allowed by the network and accesses the network using the allowed RAT type. The network notifies the communication device of the first information, allowing the communication device to select an appropriate RAT type from the first information for access. This prevents the UE from selecting an inaccessible RAT and increases the UE's access success rate.

[0041] In one possible implementation, the RAT type corresponding to the second radio access network device is included in the RAT types allowed to access the network. This can be understood as the communication device determining an appropriate RAT type based on the first information and thus selecting the second radio access network device of the appropriate RAT type.

[0042] In a fourth aspect, a communication method is provided. This method can be executed by an access and mobility management network element, or by a chip or circuit of the access and mobility management network element, but this application does not limit this. For ease of description, the following description uses the method executed by the access and mobility management network element as an example.

[0043] The method includes: an access and mobility management network element establishing a connection with a communication device via a first path with a first radio access network device;

[0044] The access and mobility management network element receives a request message from the communication device through a second path with a second radio access network device, where the request message is used to request that the communication device be registered with the network, and the request message includes indication information; the access and mobility management network element retains the connection of the first path when registering with the network through the second path according to the indication information.

[0045] In one possible implementation, the access and mobility management network element determines, based on the indication information, that the communication device supports accessing the network through two different paths at the same time, or determines that the communication device wishes to access the network through two different paths at the same time, thereby retaining the connection of the first path when registering to the network through the second path.

[0046] In a possible implementation, an access and mobility management network element obtains first information, where the first information indicates a radio access technology RAT type that allows the communication device to access a network.

[0047] In a possible implementation manner, the access and mobility management network element receives the first information from the unified data management network element or the policy control network element.

[0048] In one possible implementation, the first information does not include the RAT type corresponding to the second radio access network device, and the method further includes: the access and mobility management network element sends a registration rejection message to the communication device through the second radio access network device, and the registration rejection message includes the first information.

[0049] In one possible implementation, the access and mobility management network element determines whether the first information includes a combination of RAT types corresponding to the first radio access network device and the second radio access network device. A suitable RAT type combination is selected for the communication device through the network, thereby improving network quality and stability. For example, a combination of a terrestrial network (TN) and a non-terrestrial network (NTN) is selected for the communication device. Accessing the network through both the TN and NTN paths ensures both network quality through the TN and network coverage through the NTN.

[0050] In one possible implementation, the first information includes a combination of RAT types corresponding to the first radio access network device and the second radio access network device, and the method further includes: the access and mobility management network element sends a registration acceptance message to the communication device.

[0051] In one possible implementation, the first information does not include a combination of RAT types corresponding to the first radio access network device and the second radio access network device, and the method further includes: the access and mobility management network element sending a registration reject message to the communication device via the second radio access network device, the registration reject message including the first information; or the access and mobility management network element sending a registration accept message to the communication device via the second radio access network device, and releasing the connection of the first path. For example, the first path and the second path have the same RAT type, but one of the first path and the second path is retained based on the first information, thereby retaining the second path and releasing the first path.

[0052] The beneficial effects of the fourth aspect and certain implementation methods of the fourth aspect can be referred to the relevant description of the third aspect, and will not be repeated here.

[0053] In a fifth aspect, a communication method is provided. This method can be executed by a wireless access network device, or by a chip or circuit of the wireless access network device, although this application does not limit this. For ease of description, the following description is based on an example of execution by a wireless access network device.

[0054] The method includes: a wireless access network device receives a request message from a communication device, the request message being used to request that the communication device be registered with a network, the request message including indication information; the wireless access network device obtains identification information of a first access and mobility management network element; and the wireless access network device selects a second access and mobility management network element that is different from the first access and mobility management network element based on the identification information and indication information of the first access and mobility management network element.

[0055] In a possible implementation manner, the request message includes access network parameters, wherein the access network parameters include indication information.

[0056] In a possible implementation manner, the identification information of the first access and mobility management network element is obtained from the request message.

[0057] The beneficial effects of the above-mentioned fifth aspect and certain implementation methods of the fifth aspect can be referred to the corresponding description of the first aspect, and will not be repeated here.

[0058] In a sixth aspect, a communication method is provided. This method may be executed by a wireless access network device, or may be executed by a chip or circuit of the wireless access network device, although this application does not limit this. For ease of description, the following description will be based on an example of execution by a wireless access network device.

[0059] The method includes: a wireless access network device receives a request message from a communication device, the request message is used to request that the communication device be registered with the network, the request message includes indication information, the indication information indicates that the communication device supports accessing the network through two different paths at the same time, or indicates that the communication device hopes to access the network through two different paths at the same time; the wireless access network device selects an access and mobility management network element that supports dual connectivity according to the indication information, the access and mobility management network element that supports dual connectivity is an access and mobility management network element that supports maintaining a connection with the communication device through two different paths at the same time.

[0060] In a possible implementation manner, the request message includes access network parameters, wherein the access network parameters include indication information.

[0061] In one possible implementation, the request message also includes identification information of the first access and mobility management network element, and the method also includes: the wireless access network device determines whether the first access and mobility management network element supports dual connection based on the identification information of the first access and mobility management network element; the wireless access network device selects the access and mobility management network element that supports dual connection based on the indication information, including: when the first access and mobility management network element supports dual connection, the wireless access network device selects the first access and mobility management network element to access the network.

[0062] In one possible implementation, when the first access and mobility management network element does not support dual connectivity, the radio access network device selects a second access and mobility management network element different from the first access and mobility management network element to access the network. The beneficial effects of the sixth aspect and certain implementations of the sixth aspect can be referred to the description related to the third aspect, and are not repeated here.

[0063] In a seventh aspect, a communication method is provided, which can be executed by a first network element, or by a chip or circuit of the first network element, which is not limited in this application. For ease of description, the following description is based on an example of execution by the first network element.

[0064] The method includes: a first network element obtains indication information, where the indication information indicates that a communication device supports accessing a network through two different paths at the same time; the first network element determines first information of the communication device based on the indication information, where the first information indicates a radio access technology RAT type that allows the communication device to access the network; and the first network element sends the first information to an access and mobility management network element.

[0065] In the communication method provided based on the seventh aspect, the first information is notified to the communication device through the first network element, so that the communication device selects a suitable RAT type for access from the first information, thereby avoiding the UE from selecting an inaccessible RAT and increasing the success rate of UE access.

[0066] In one possible implementation, the first network element receives the indication information from the access and mobility management network element; or the first network element obtains the indication information based on subscription data of the communication device. For example, the subscription data of the communication device includes the indication information, or the subscription data indicates that the communication device supports dual connectivity.

[0067] In a possible implementation manner, the first network element is a unified data management network element or a policy control network element.

[0068] In an eighth aspect, a communication device is provided, comprising: a module for executing any of the communication methods described above, such as a transceiver module and a processing module. The transceiver module is configured to execute corresponding message sending and receiving actions, and the processing module can be configured to execute all actions except sending and receiving messages.

[0069] Optionally, the communication device described in the eighth aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device can execute any communication method executed by the terminal device described above.

[0070] In a ninth aspect, a communication device is provided, comprising: a module for executing any of the communication methods described above for the access and mobility management network element, such as a transceiver module and a processing module. The transceiver module is configured to execute corresponding message sending and receiving actions, and the processing module is configured to execute all actions except sending and receiving information.

[0071] Optionally, the communication device described in the ninth aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device can execute any communication method performed by the access and mobility management network element described above.

[0072] In a tenth aspect, a communication device is provided, comprising: a module for executing any of the communication methods described above for execution by the wireless access network device, such as a transceiver module and a processing module. The transceiver module is configured to execute corresponding message sending and receiving actions, and the processing module is configured to execute all actions except sending and receiving information.

[0073] Optionally, the communication device described in the tenth aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device can execute any communication method executed by the wireless access network device described above.

[0074] In an eleventh aspect, a communication device is provided, comprising: a processor configured to execute instructions stored in a memory, so as to enable the communication device to perform any of the communication methods described above.

[0075] In a possible design solution, the communication device may further include the memory. The memory may be integrated with the processor or provided separately.

[0076] In a twelfth aspect, a communication device is provided, comprising: a processor configured to execute instructions stored in a memory, so as to enable the communication device to perform any communication method described above by the access and mobility management network element.

[0077] In a possible design solution, the communication device may further include the memory. The memory may be integrated with the processor or provided separately.

[0078] In a thirteenth aspect, a communication device is provided, comprising: a processor configured to execute instructions stored in a memory, so that the communication device performs any communication method described above by the wireless access network device.

[0079] In a possible design solution, the communication device may further include the memory. The memory may be integrated with the processor or provided separately.

[0080] In a fourteenth aspect, a communication system is provided, comprising: a communication device, the communication device being used to execute the methods in the above-mentioned first to third aspects and any possible implementation manner thereof.

[0081] Optionally, the communication system further includes an access and mobility management network element, which is used to execute the method in the fourth aspect and any possible implementation manner thereof.

[0082] Optionally, the communication system further includes a wireless access network device, and the wireless access network device is used to execute the method in the above-mentioned fifth aspect and sixth aspect and any possible implementation manner thereof.

[0083] Optionally, the communication system further includes a unified data management network element or a policy control network element, which is used to execute the method in the above-mentioned seventh aspect and any possible implementation thereof.

[0084] In the fifteenth aspect, a computer-readable storage medium is provided, which stores a computer program or code. When the computer program or code is run on a computer, the computer executes the method in any one of the above-mentioned aspects 1 to 7 and any possible implementation thereof.

[0085] In the sixteenth aspect, a chip is provided, comprising at least one processor, wherein the at least one processor is coupled to a memory, the memory being used to store a computer program, and the processor being used to call and run the computer program from the memory, so that a device equipped with the chip system executes the method in any one of the above-mentioned first to seventh aspects and any possible implementation thereof.

[0086] The chip may include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

[0087] In the seventeenth aspect, a computer program product is provided, comprising: a computer program code, which, when the computer program code is run on the computer, executes the method in any one of the above-mentioned aspects from the first to the seventh aspect and any possible implementation thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] FIG1 is a schematic diagram of a communication system provided in an embodiment of the present application.

[0089] FIG2 is a schematic diagram of a registration process under a 3GPP access technology provided in an embodiment of the present application.

[0090] FIG3 is a schematic diagram of the structure of a globally unique temporary identifier provided in an embodiment of the present application.

[0091] FIG4 is a schematic diagram of a dual-connection architecture provided in an embodiment of the present application.

[0092] FIG5 is a flow chart of a communication method 500 provided in an embodiment of the present application.

[0093] FIG6 is a flow chart of a communication method 600 provided in an embodiment of the present application.

[0094] FIG7 is a flow chart of a communication method 700 provided in an embodiment of the present application.

[0095] FIG8 is a flow chart of a communication method 800 provided in an embodiment of the present application.

[0096] FIG9 is a flow chart of a communication method 900 provided in an embodiment of the present application.

[0097] FIG10 is a flow chart of a communication method 1000 provided in an embodiment of the present application.

[0098] FIG11 is a flow chart of a communication method 1100 provided in an embodiment of the present application.

[0099] FIG12 is a flow chart of a communication method 1200 provided in an embodiment of the present application.

[0100] FIG13 is a flow chart of a communication method 1300 provided in an embodiment of the present application.

[0101] FIG14 is a flow chart of a communication method 1400 provided in an embodiment of the present application.

[0102] FIG15 is a schematic structural diagram of a communication device 1000 provided in an embodiment of the present application.

[0103] FIG16 is a schematic structural diagram of a communication device 2000 provided in an embodiment of the present application.

[0104] FIG17 is a schematic structural diagram of a chip system 3000 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0105] The technical solution in this application will be described below with reference to the accompanying drawings.

[0106] The technical solutions provided in this application can be applied to various communication systems, such as new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, etc. The technical solutions provided in this application can also be applied to device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication systems or other communication systems.

[0107] In a communication system, the part operated by an operator may be referred to as a public land mobile network (PLMN), or as an operator network, etc. PLMN is a network established and operated by the government or an operator approved by it for the purpose of providing land mobile communication services to the public. It is mainly a public network in which mobile network operators (MNOs) provide mobile broadband access services to users. The PLMN described in the embodiments of the present application may specifically be a network that complies with the standards of the 3rd Generation Partnership Project (3GPP), referred to as a 3GPP network. 3GPP networks generally include but are not limited to fifth-generation mobile communication (5th-generation, 5G) networks, fourth-generation mobile communication (4th-generation, 4G) networks, and other future communication systems, such as sixth-generation mobile communication (6th-generation, 6G) networks.

[0108] For ease of description, the embodiments of this application will be described using PLMN or 5G network as an example.

[0109] Figure 1 is a schematic diagram of a network architecture, taking the 5G network architecture based on a service-based architecture (SBA) in a non-roaming scenario, as defined in the 3GPP standardization process, as an example. As shown in Figure 1 , the network architecture may include a terminal device component, a data network (DN) component, and a carrier network (PLMN) component. The carrier network PLMN component may include, but is not limited to, a (radio) access network (R)AN) 120 and a core network (CN) component.

[0110] The following is a brief description of the functions of the network elements in each part.

[0111] The terminal equipment portion may include UE 110, which is a device that provides voice and / or data connectivity to users. UE 110 may also be referred to as user equipment (UE). In this application, UE 110 is a device with wireless transceiver capabilities that can communicate with one or more CN devices via access network equipment (or access equipment) in (radio) access network (R)AN 120. UE 110 may also be referred to as an access terminal, terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, user agent, or user device. UE 110 may be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water (e.g., on ships); or in the air (e.g., on airplanes, balloons, and satellites). UE 110 may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a smartphone, a mobile phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), or the like. Alternatively, UE 110 may also be a handheld device with wireless communication capabilities, a computing device, or other device connected to a wireless modem, an in-vehicle device, a wearable device, an unmanned aerial vehicle device, or a terminal in the Internet of Things, the Internet of Vehicles, a terminal of any form in a 5G network and future networks, a relay user device, or a terminal in a future evolved 6G network, etc. Among them, the relay user device may be, for example, a 5G residential gateway (RG). For example, UE 110 may be a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The terminal device here refers to a 3GPP terminal. The embodiments of the present application do not limit the type or category of the terminal device. For ease of explanation, the present application will be described below using UE as an example to refer to a terminal device.

[0112] (R)AN 120 may include one or more access network elements or access network devices, and the interface between the access network device and the terminal device may be a Uu interface (or air interface, that is, the messages exchanged between the access network device and the terminal device may be called air interface messages). Of course, in future communications, the interface name may remain unchanged or may be replaced by other names, and this application is not limited to this. (R)AN 120 is a device that provides wireless communication functions for UE 110, and can connect the terminal device to a node or device of a wireless network, and may also be called a network device. (R)AN 120 can be regarded as a subnet of the operator network, and is an implementation system between the service node in the operator network and UE 110. For example, UE 110 can connect to the service node of the operator network through (R)AN 120, thereby obtaining the services provided by the service node. (R)AN 120 includes but is not limited to: the next generation node base station (gNB) in the 5G system, the evolved node B (eNB) in the long term evolution (LTE), the radio network controller (RNC), the node B (NB), the base station controller (BSC), the base transceiver station (BTS), the home base station (for example, home evolved node B, or home node B, HNB), the base band unit (BBU), the transmitting and receiving point (TRP), the transmitting point (TP), the small base station equipment, the mobile switching center, or the network equipment in the future network, etc.The access network device may also be a module or unit that performs the functions of a base station, for example, a centralized unit (CU) and a distributed unit (DU); in a possible network structure, the CU may be used to support communications under protocols such as radio resource control (RRC), packet data convergence protocol (PDCP), and service data adaptation protocol (SDAP); and the DU may be used to support communications under radio link control (RLC) layer protocols, medium access control (MAC) layer protocols, and physical layer protocols. The embodiments of the present application do not limit the specific technology and specific device form adopted by the access network device. In systems using different wireless access technologies, the names of devices having access network device functions may be different. For the convenience of description, in all embodiments of the present application, the above-mentioned devices that provide wireless communication functions for UE 110 are collectively referred to as access network devices or RAN for short. It should be understood that this document does not limit the specific type of access network device.

[0113] The CN part may include but is not limited to the following network functions (NF): user plane function (UPF) 130, policy control function (PCF) 131, unified data management function (UDM) 132, authentication server function (AUSF) 133, access and mobility management function (AMF) 134, and session management function (SMF) 135.

[0114] The data network DN 140 is usually a network outside the operator's network, such as a third-party network or an Internet service.

[0115] The following is a brief description of the NF functions included in CN.

[0116] 1. UPF 130 is a gateway provided by the operator and serves as the gateway for communication between the operator network and DN 140. UPF 130 network functions include packet routing and transmission, packet detection, service usage reporting, Quality of Service (QoS) processing, uplink packet detection, downlink packet storage, and other user-plane-related functions. In future communication systems, the user plane function network element may still be a UPF network element, or may have other names, which are not limited in this application.

[0117] 2. PCF 131 is a control plane function provided by the operator. It primarily supports providing a unified policy framework to control network behavior, provides policy rules to control-layer network functions, and is responsible for obtaining user subscription information related to policy decisions. Exemplarily, PCF 133 can be divided into two different PCFs: UE-PCF and AMF-PCF. The UE-PCF can be used to generate UE policy (UE policy), i.e., the policy sent to UE 110. The transmission path is: UE-PCF--->AMF--->UE. In this case, AMF 134 does not parse the content of the UE policy; AMF 134 transparently transmits the UE policy. The AM-PCF can be used to generate AM policy, i.e., the access management policy sent to AMF 134. The transmission path is: UE-PCF--->AMF. Furthermore, AMF 134 can also send some or all access management policies to RAN 120. In future communication systems, the policy control function network element may still be a PCF network element, or may have other names, which are not limited in this application.

[0118] 3. The UDM 132 is a control plane function provided by the operator and is responsible for storing information such as the subscriber permanent identifier (SUPI) of subscribers in the operator network, the publicly available general public subscription identifier (GPSI) of subscribers, and credentials. The SUPI is encrypted during transmission, and the encrypted SUPI is called a hidden subscriber subscription identifier (SUCI). This information stored by the UDM network function 132 can be used for authentication and authorization of UE 110 accessing the operator network. Subscribers of the operator network may specifically be users who use services provided by the operator network, such as users using China Telecom's SIM cards or China Mobile's SIM cards. The subscriber's credentials may be a small file containing a long-term key stored in a mobile phone SIM card or information related to mobile phone SIM card encryption, used for authentication and / or authorization. In future communication systems, the unified data management function network element may still be a UDM network element, or may have other names, which are not limited in this application.

[0119] 4. AUSF 133 is a control plane function provided by the operator, which is usually used for level one authentication, that is, authentication between the terminal device 110 (subscriber) and the operator network. After the AUSF network function 133 receives the authentication request initiated by the subscriber, it can authenticate and / or authorize the subscriber through the authentication information and / or authorization information stored in the UDM network function 132, or generate the authentication and / or authorization information of the subscriber through the UDM network function 132. The AUSF network function 133 can feedback the authentication information and / or authorization information to the subscriber. In future communication systems, the authentication server function network element can still be an AUSF network element, or it can have other names, which are not limited in this application.

[0120] 5. The AMF 134 is a control plane network function provided by the operator network and is responsible for access control and mobility management for UE 110 accessing the operator network. For example, it includes functions such as mobility state management, allocating temporary user identities, authenticating and authorizing users, etc. In future communication systems, the access management network element may still be the AMF network element, or may have other names, which are not limited in this application.

[0121] 6. SMF 135 is a control plane network function provided by the operator network. It is responsible for managing the protocol data unit (PDU) session of UE 110 (including session establishment, modification, and release). It is used for the selection and reselection of user plane function network elements, the allocation of Internet Protocol (IP) addresses for terminal devices, and quality of service (QoS) control. A PDU session is a channel for transmitting PDUs, and the SMF network function 135 is responsible for establishing, maintaining, and deleting PDU sessions. The SMF network function 135 includes session management (e.g., session establishment, modification, and release, including tunnel maintenance between the user plane function (UPF) 130 and the (R)AN 120), selection and control of the UPF network function 130, service and session continuity (SSC) mode selection, roaming, and other session-related functions. In future communication systems, the session management function network element may still be an SMF network element, or may have other names, which are not limited in this application.

[0122] It is understood that the above network elements or functions can be physical entities in hardware devices, software instances running on dedicated hardware, or virtualized functions instantiated on a shared platform (e.g., a cloud platform). Simply put, an NF can be implemented by hardware or software.

[0123] In Figure 1, Npcf, Nudm, Nausf, Namf, Nsmf, N1, N2, N3, N4 and N6 are interface serial numbers. For example, the meaning of the above interface serial numbers can be found in the meaning defined in the 3GPP standard protocol, and this application does not limit the meaning of the above interface serial numbers. It should be noted that the interface name between the various network functions in Figure 1 is only an example. In a specific implementation, the interface name of the system architecture may also be other names, which is not limited by this application. In addition, the name of the message (or signaling) transmitted between the above network elements is only an example and does not constitute any limitation on the function of the message itself.

[0124] It should be noted that in the architecture shown in Figure 1, the interface between the radio access network and the 5G core network is called the NG interface (not shown in the figure). gNBs are connected to each other via the Xn interface, and the gNB and 5GC are connected via the NG interface. The NG interface includes the NG-C interface and the NG-U interface. The NG-C interface is a control plane interface that connects the gNB and the AMF and transmits control plane data. The NG-U interface is a user plane interface that connects the gNB and the UPF and transmits user plane data. The main functions of the NG interface include but are not limited to: paging, UE context connection, UE mobility management, PDU session management, NAS signaling transmission, etc.

[0125] It should be understood that the above network architecture 100 is only described from the perspective of a service-based architecture. In this service-based architecture, the PLMN can combine some or all network functions in an orderly manner according to specific scenario requirements, realizing customized network capabilities and services, thereby deploying dedicated networks for different services, that is, realizing 5G network slicing. Network slicing technology enables operators to respond to customer needs more flexibly and quickly, and supports flexible allocation of network resources.

[0126] For ease of explanation, in the embodiments of this application, network functions (such as UPF 130 ... SMF 135) are collectively referred to as NFs. This means that the NFs described later in the embodiments of this application can be replaced with any network function. Furthermore, in the embodiments of this application, UE 110 is referred to as a UE. This means that any UE described later in the embodiments of this application can be replaced with a terminal device. Figure 1 only schematically illustrates some network functions, and the NFs described later are not limited to the network functions shown in Figure 1.

[0127] It should be understood that the AMF, SMF, UPF, AUSF, PCF, and UDM shown in Figure 1 can be understood as network elements used to implement different functions in the core network, for example, they can be combined into network slices as needed. These core network network elements can be independent devices or integrated into the same device to implement different functions. This application does not limit the specific form of the above network elements.

[0128] It should also be understood that the above naming is defined only to facilitate the distinction between different functions and should not constitute any limitation to this application. This application does not exclude the possibility of adopting other naming in 5G networks and other future networks. For example, in a 6G network, some or all of the above network elements may continue to use the terminology used in 5G, or may adopt other names.

[0129] To facilitate understanding of the embodiments of the present application, some terms used in the embodiments of the present application are explained below to facilitate understanding by those skilled in the art.

[0130] 1) Access type and access technology:

[0131] The access type includes a 3GPP access type and a non-3GPP access type.

[0132] 3GPP access types include, but are not limited to, the following access technologies: LTE access technology (corresponding to 4G cellular networks), NR access technology (corresponding to 5G cellular networks), 3GPP-defined satellite access technology, or subsequently evolved cellular access technologies; 3GPP-defined satellite access technologies can be further categorized as low-orbit satellites, medium-orbit satellites, and geostationary satellites. A 3GPP access network refers to an access network with a 3GPP access type (also referred to as an access method).

[0133] Non-3GPP access types include, but are not limited to, the following access technologies: untrusted non-3GPP access technology (for example, accessing the core network through wireless access nodes purchased by individuals), trusted non-3GPP access technology (for example, accessing the core network through wireless access nodes deployed by operators), wireline access technology (for example, Broadband Forum (BBF) access technology, Cable access technology, etc.), IEEE802.11 access technology, and non-3GPP access technology connected through a standalone non-public network (SNPN). For example, access methods using non-3GPP access technology may include wired, Wireless Fidelity (WiFi), Bluetooth, ZigBee, and other access methods. A non-3GPP access network refers to an access network whose access type is a non-3GPP access type.

[0134] 2) The process of determining access type and access technology.

[0135] When the UE performs the registration process, it sends an AN message to the access network device.

[0136] The access network device may be a 3GPP access network device (e.g., RAN) or a non-3GPP access network device. For example, the non-3GPP access network device includes: a non-3GPP interworking function (N3IWF) network element, a trusted non-3GPP gateway function (TNGF) network element, a trusted WLAN interworking function (TWIF) network element, or a wireline access gateway function (W-AGF) network element, where W-AGF may also be referred to as AGF.

[0137] The access network device sends a registration request message to the AMF. After receiving the registration request message, the AMF can determine the access type and access technology registered by the UE based on the information of the access network device.

[0138] In one example, the AMF determines the access type registered by the UE based on the access network device. For example, if the registration request message is sent or forwarded by a 3GPP access network device (such as RAN), the AMF can determine that the access type registered by the UE is a 3GPP access type. For another example, if the registration request message is sent or forwarded by a non-3GPP access network device, such as N3IWF, TNGF, TWIF, W-AGF, etc., the AMF can determine that the access type used by the UE is a non-3GPP access type.

[0139] In another example, the AMF can further determine the access technology registered by the UE. For example, for the 3GPP access type, the AMF can further determine that the access technology is LTE access technology, NR access technology, satellite access technology, etc. based on the radio access network device information, such as the global radio access network node identifier (Global RAN Node IDs) associated with the N2 interface and the tracking area (tracking area) indicated by the radio access network device. For another example, when the 5G access network node has a global N3IWF node identifier (Global N3IWF Node ID), the access technology is untrusted non-3GPP. When the 5G access network node has a global TNGF node identifier (Global TNGF Node ID) or a global TWIF node identifier (Global TWIF Node ID), the access technology is trusted non-3GPP, etc.

[0140] In a multi-connectivity scenario, after a UE registers multiple times, the UE may register for one or more access types. For example, in a dual-connectivity scenario, the UE may register twice using the 3GPP access type. In this case, the UE registers for the 3GPP access type. In another example, the UE registers for the first time using the 3GPP access type and the second time using the non-3GPP access type. In this case, the UE registers for both the 3GPP access type and the non-3GPP access type.

[0141] 3) Registration process, including but not limited to: registration process under 3GPP access technology, registration process under untrusted non-3GPP access technology, registration process under trusted non-3GPP access technology, and registration process under wired access technology.

[0142] When a UE first accesses the network, it initiates an Initial Registration process. In addition, the UE can also initiate other types of registrations. For example, when the UE needs to initiate a registration process due to mobility, the UE initiates a Mobility Registration Update process; when the UE is in the Registered state and initiates a registration process due to the expiration of the Periodic Registration Update timer, the UE initiates a Periodic Registration Update process; when the UE initiates a registration process in a service-restricted state, the UE initiates an Emergency Registration process.

[0143] The following takes the initial registration process as an example.

[0144] FIG2 shows a possible UE registration process under 3GPP access technology in current technology.

[0145] Step 201: The UE sends an access network (AN) message to the RAN.

[0146] The AN message includes AN parameters and a Registration Request message. The AN parameters contain parameter information used by the RAN to select the AMF. For example, the parameter information may include one or more of the following: PLMN identifier, network identification (NID), etc. The Registration Request message includes a Registration Type, a UE identifier, etc. The Registration Type may be an initial registration. The UE identifier may be a SUCI.

[0147] Step 202: RAN selects AMF based on AN parameters.

[0148] The AN parameter is the AN parameter in the AN message in step 201 .

[0149] Step 203: The RAN sends the registration request message received in step 201 to the AMF selected in step 202.

[0150] Step 204: UE, AMF, AUSF, UDM, etc. interact to perform authentication and security procedures.

[0151] For example, first, the AMF selects the AUSF and sends an authentication request message to the AUSF. The AUSF performs the authentication process on the UE and obtains authentication data or information used for authentication from the UDM. After the authentication is completed, the AUSF sends the security anchor functionality (SEAF) key to the AMF. The AMF can derive the NAS security key based on the SEAF key.

[0152] The AMF then indicates to the UE that the authentication was successful. For example, the AMF sends a NAS Security Mode Command to the UE to activate NAS security. The NAS Security Mode Command includes an EAP-Success indication, indicating that the EAP-authentication and key agreement (EAP-AKA') authentication performed by the core network was successful. The RAN forwards the NAS Security Mode Command sent by the AMF to the UE and sends the NAS Security Mode Complete message sent by the UE to the AMF.

[0153] After successful authentication, the AMF creates a UE context, which includes information about the N2 connection between the RAN and the AMF for the UE.

[0154] Step 205: AMF interacts with UDM to obtain the UE's subscription data.

[0155] The AMF can obtain relevant service information based on the UE's subscription data, such as the UE's service level, service traffic limit, service fee, etc. This information can be used to control the UE's service access and restriction, as well as billing and settlement.

[0156] Step 206: The AMF allocates a 5G-GUTI to the UE and sends a NAS Registration Accept message to the RAN.

[0157] Among them, 5G-GUTI is a UE identifier, which can also be understood as a temporary identity identifier of the UE. The AMF serving the UE allocates 5G-GUTI to the UE, and the 5G-GUTI can be used for subsequent registration or session establishment processes. The NAS registration acceptance message includes 5G-GUTI. For example, as shown in Figure 3, the 5G-GUTI consists of two parts: a globally unique AMF identifier (GUAMI) and a 5G temporary mobile subscriber identity (5G-TMSI). Among them, GUAMI includes a mobile country code (MCC), a mobile network code (MNC), an AMF region ID (AMF Region ID), an AMF set ID (AMF set ID), and an AMF pointer (AMF Pointer). The combination of MCC and MNC uniquely identifies a PLMN, which has multiple regions. The AMF Region ID identifies a region in the PLMN, which has multiple AMF sets. The AMF set ID identifies an AMF set within a region, which has multiple AMFs. The AMF pointer identifies an AMF within an AMF set. The 5G-TMSI is a temporary identifier assigned by the AMF to the UE and is unique within the AMF. Therefore, it can be understood that the GUAMI uniquely identifies an AMF, and the 5G-TMSI uniquely identifies the UE within the scope of that AMF.

[0158] In addition, the above-mentioned AMF set ID, AMF Pointer and 5G-TMSI can constitute the 5G system temporary mobile user identity (5G S-temporary mobile subscriber identity, 5G-S-TMSI). It can be understood that 5G-S-TMSI is a simplified 5G-GUTI. Since the base station itself is deployed in a fixed location, it will not connect to AMFs in multiple regions. For example, the base station deployed by China Mobile in Shanghai will only connect to the AMF in the Shanghai area, not to the AMF in Beijing. Therefore, when selecting an AMF, RAN can ignore the AMF Region ID. By providing a simplified 5G-S-TMSI for RAN to select an AMF, the UE can make the air interface signaling message shorter, improve air interface efficiency, and save signaling resources. Therefore, 5G-S-TMSI can also be used to identify an AMF. In other words, 5G-S-TMSI is also a kind of AMF identification information.

[0159] Exemplarily, the NAS registration accept message may be included in the N2 message.

[0160] Step 207: The RAN forwards the NAS registration accept message sent by the AMF to the UE.

[0161] Since the UE obtains the 5G-GUTI during the initial registration process, in subsequent non-initial registration processes, the UE initiates the registration process by sending an access network message to the RAN. The UE identifier in the registration request message in step 201 is the 5G-GUTI, and the AN parameter can contain the identification information of the AMF, such as GUAMI or 5G-S-TMSI. The RAN needs to select an appropriate AMF to serve the UE. Since there is already an AMF serving the UE, the RAN will give priority to the AMF that previously served the UE.

[0162] The UE obtains a 5G-GUTI during the initial registration process. The 5G-GUTI is a temporary identity of the UE, which is allocated by the AMF serving the UE. When the UE subsequently registers with the network, the identification information of the AMF (such as 5G-S-TMSI or GUAMI) can be provided in the access network message. The RAN can select the AMF indicated by the 5G-S-TMSI or GUAMI.

[0163] When the identification information of the AMF provided by the UE is inappropriate (for example, the originally connected AMF fails, or the UE moves out of the original range, resulting in the base station being unable to connect to the original AMF), the RAN needs to reselect an AMF. When selecting an AMF, the RAN will refer to one or more of the following factors: the AMF set indicated by the GUAMI, the requested slice, the local operator policy and other information. For example, when the RAN considers the requested slice when selecting the AMF, the UE will bring the slice information required for the request when sending a registration request to the RAN, and the RAN side will also save the slice information supported by the AMF (for example, the RAN can obtain the slice information supported by the AMF when the RAN initially establishes a connection with the AMF), so that the RAN will select an AMF that can meet the slice requirements requested by the UE.

[0164] In addition, the AMF reselected by the RAN can find the original AMF based on the identification information of the AMF provided by the UE and request the UE context from the original AMF.

[0165] 4) Dual-connectivity architecture:

[0166] Figure 4 exemplifies a dual-connectivity architecture applicable to embodiments of the present application. For example, dual connectivity can be referred to as Dual Steer. In this architecture, a UE simultaneously accesses the same network through two 3GPP access type connections. The two 3GPP access network devices corresponding to the 3GPP access type may be RANs. For example, a UE can use a single SIM card to simultaneously access the same PLMN through two different RANs. Exemplarily, the two 3GPP access type connections correspond to two paths. As shown in Figure 4 , the first path is for the UE to connect to the network via RAN1 and the AMF. As described above, to establish the second path, the UE initiates registration via RAN2. Registration initiated via RAN2 is non-initial registration. Therefore, if the original AMF in the first path is available, RAN2 selects the original AMF based on the AMF identification information carried by the UE. Therefore, the second path is for the UE to connect to the network via RAN2 and the AMF. The connection between the UE and the AMF is N1, and the connection between the AMF and the RAN is N2.

[0167] It should be noted that accessing the same network through two connections of the 3GPP access type at the same time does not mean that the UE must send or receive data through two paths at the same time. Instead, it means that the UE can access the network and send or receive data through the first path, and can also access the network and send or receive data through the second path.

[0168] In this application, dual connectivity refers to accessing the network through two different paths at the same time, and the two different paths are connected to two different radio access network devices and two identical or different access and mobility management network elements. A UE that supports dual connectivity means that the UE supports accessing the network through two different paths at the same time, and an AMF that supports dual connectivity means that the AMF supports maintaining a connection with the UE through two different paths at the same time. It should be noted that in this application, the names of dual connectivity or multi-connectivity can be further expanded as follows:

[0169] 1: Dual / multiple radio capability. Dual / multiple radio capability indicates that the UE supports the ability to access the network through dual / multiple radios.

[0170] 2: Dual / multiple 3GPP RAT: Dual / multiple 3GPP RAT indicates that the UE accesses the network through dual / multiple 3GPP RAT.

[0171] 3: Dual / multiple steer: Dual / multiple steer indicates that the UE accesses the network through a dual / multiple steer path.

[0172] 4: Dual / multiple 3GPP access: Dual / multiple 3GPP access indicates that the UE accesses the network through dual / multiple 3GPP paths.

[0173] 5: Dual / multiple 3GPP access type: The dual / multiple 3GPP access type indicates that the UE accesses the network through the dual / multiple 3GPP access type.

[0174] 6: Dual / Multiple connectivity: Dual / Multiple connectivity indicates that the UE accesses the network through dual / multiple different paths.

[0175] 7: Dual / multiple registration: Dual / multiple registration indicates that the UE registers with the network through dual / multiple different paths.

[0176] 8: Same access type: The same access type indicates that the UE accesses the network through two or more paths of the same access type.

[0177] 9: Same access technology (same RAT): Same access technology indicates that the UE accesses the network through dual / multiple paths using the same access technology.

[0178] 10: Same access network: The same access network indicates that the UE accesses the same network through dual / multiple paths.

[0179] 11: Dual / multiple registration within same access type. Dual / multiple registration within same access type indicates that the UE registers to the network through dual / multiple paths of the same access type.

[0180] 5) N2 connection:

[0181] When the UE accesses the network, the connection between the RAN and the AMF is the N2 connection. In a single-connection scenario, the UE is connected to the network through a path of the RAN and the AMF. In a mobile scenario, for example, when the UE changes the connected RAN due to mobility, the UE will send a 5G-GUTI to the new RAN, and the new RAN will select the AMF that previously served the UE. For related descriptions, please refer to the above selection of the AMF when not initially registered to the network. The new RAN establishes a new N2 connection with the AMF. The AMF can determine that the UE context has been saved based on the 5G-GUTI, and then determine that an N2 connection has been established for the UE before, and thus it will be considered that the new N2 connection with the new RAN is to replace the old N2 connection. Therefore, the AMF will initiate the process of releasing the N2 connection, that is, releasing the old N2 connection. This process allows the AMF to manage and release the logical NG connection corresponding to the UE. The AMF can trigger the process by sending a UE CONTEXT RELEASE COMMAND to the old RAN. The message may include the AMF UE NGAP ID and the RAN UE NGAP ID. After receiving the message, the old RAN releases the signaling and user plane data resources and replies with a UE CONTEXT RELEASE COMPLETE message to the AMF.

[0182] When a UE accesses the same network via dual connectivity as shown in Figure 4, and according to existing technologies, registers on two different RANs along the two paths, the two different RANs along the two paths will select the same AMF to access the network. For example, the AMF first creates a UE context on the first path and establishes an N2 connection for the UE with RAN1. However, when the UE registers on the second path through RAN2 and the same AMF, the AMF determines that the UE context has already been saved based on the UE's identifier and therefore believes that the second path registration is intended to replace RAN1 on the first path. Therefore, the N2 connection on the first path will be released. In other words, the AMF can only maintain one N2 connection at a time, so the UE cannot access the same network through two different paths simultaneously.

[0183] In order to solve the above problems, this embodiment proposes the following method.

[0184] As shown in FIG5 , a method 500 applicable to the present application is introduced. Through the method 500, a UE can access the same network through dual connectivity. Dual connectivity is two connections of the 3GPP access type, corresponding to two paths of different radio access network devices. The method includes the following steps:

[0185] Step 501: The UE accesses the network through a first path connecting RAN1 and AMF1.

[0186] It should be noted that before the UE accesses the network through the first path connecting RAN1 and AMF1, the UE registers with the network through the first path connecting RAN1 and AMF1. During the registration process, AMF1 creates the UE context. The UE context includes information about the connection (N2 connection) between AMF1 and the first path of RAN1. When the registration is successful, it can be understood that the UE can access the network through the first path.

[0187] For the description of registration with the network, please refer to the registration process of UE under 3GPP access technology as shown in Figure 2, which will not be repeated here.

[0188] It should be noted that, in this embodiment, the UE's registration process for the first path can be either initial registration or non-initial registration. When the registration type of the UE registering to the network through RAN1 is initial registration, the UE sends SUCI. During the registration process, AMF1 sends a 5G-GUTI to the UE. The 5G-GUTI includes the identification information of the AMF, which is used by the UE to select the AMF in the non-initial registration process. When the registration type of the UE registering to the network through RAN1 is non-initial registration, the UE sends a 5G-GUTI, and RAN1 selects the corresponding AMF based on the AMF's identification.

[0189] Step 510: The UE sends an AN message to RAN2.

[0190] In one possible implementation, the AN parameter in the AN message includes indication information and identification information of AMF1 (e.g., GUAMI or 5G-S-TMSI). The indication information is used by RAN2 to select an AMF different from AMF1. Exemplarily, the indication information indicates that the UE supports simultaneous access to the network through two different paths, or indicates that the UE wishes to simultaneously access the network through two different paths. Alternatively, the indication information indicates the selection of a different AMF. After receiving the indication information, RAN2 will select an AMF different from AMF1 based on the indication information and the identification information of AMF1.

[0191] Optionally, the AN message includes dual-diversion indication information, and the dual-diversion indication information is used by the UDM to save two sets of contexts for the UE. Exemplarily, the dual-diversion indication information indicates that the UE is in a dual-connection state, or indicates that two sets of contexts are saved. The dual-diversion indication information can be carried in the AN parameters in the AN message or in the registration request message, or exist in parallel with the AN parameters and the registration request message in the AN message. The AN parameters include the dual-diversion indication information, and RAN2 can obtain the dual-diversion indication information and send it to the AMF through the N2 message. The registration request message includes the dual-diversion indication information, and the dual-diversion indication information can be a field in the registration type. For example, the dual-diversion indication information is a newly added registration type. The exemplary name of the newly added registration type can be DualSteer Registration. The name is not limited here. The registration type is DualSteer Registration, which is used to indicate to the network that the registration is for the second path of dual-connection registration for the UE. When the dual-diversion indication information exists in parallel with the AN parameters and the registration request message in the AN message, both RAN and AMF can parse the dual-diversion indication information.

[0192] This embodiment is described by taking an example in which the UE selects RAN2 and sends an AN message to RAN2 to request registration with the network. It should be noted that RAN2 is different from RAN1.

[0193] It should be noted that when the UE determines that it wants to access the network through two different paths at the same time, step 510 is executed.

[0194] In one possible implementation, the UE determines, based on multi-connection information (e.g., DualSteer information), that it can access the network through two paths, or that it wishes to access the network through two different paths simultaneously. However, at this time, the UE only has one path to access the network through RAN1, so the UE may register with the network through the second path, i.e., executing step 510. Exemplarily, the multi-connection information may be obtained by the UE based on the service. For example, if the current path cannot meet the rate requirements of a certain video service, the UE may determine, based on the service, that it wants to use multiple paths to access the network, thereby executing step 510.

[0195] In one possible implementation, the UE may obtain multi-connection information (e.g., DualSteer information) based on a user's operation instruction. For example, the user may turn on the DualSteer switch on the UE, and further, the UE may enter the DualSteer state based on the user's operation instruction.

[0196] In another possible implementation, the UE may obtain multi-connection support information (e.g., DualSteer information) based on pre-configured information. For example, the UE factory configuration may pre-configure information indicating that the UE supports DualSteer, e.g., the UE supports simultaneous access to the network via two different paths.

[0197] Step 511: RAN2 selects AMF.

[0198] In one possible implementation, the AN parameter in the AN message includes indication information and identification information of AMF1 (for example, GUAMI or 5G-S-TMSI), and RAN2 selects another AMF different from AMF1 based on the indication information and the identification information of AMF1.

[0199] In this embodiment, RAN2 selects AMF2, and the path connecting RAN2 and AMF2 is the second path as an example for description. AMF2 and AMF1 selected by RAN2 are different AMFs.

[0200] Step 512: RAN2 sends a registration request message to AMF2.

[0201] Optionally, the registration request message also includes dual-split indication information.

[0202] In one possible implementation, RAN2 sends a next generation application protocol (NGAP) message, also referred to as an N2 message, to AMF2, wherein the N2 message includes the registration request message.

[0203] Step 513: AMF2 triggers the authentication and security procedure with the UE, AUSF, and UDM.

[0204] In one possible implementation, AMF2 does not have the UE context, so it creates a UE context for the UE. Exemplarily, AMF2 determines that it does not have the UE context based on the UE identifier (such as 5G-GUTI).

[0205] For related descriptions, please refer to the relevant instructions in the above step 204, which will not be repeated here.

[0206] Step 514: AMF2 sends a registration request (Nudm_UECM_Registration request) to UDM.

[0207] This registration request is used by AMF2 to register with UDM as the AMF serving the UE, and AMF2 registers the UE context with UDM.

[0208] In one possible implementation, the registration request also includes dual-split indication information. After the UDM obtains the dual-split indication information, it saves two sets of contexts for the UE. It is understood that when the UDM saves the second set of contexts for the same UE, it does not send a deregistration request to AMF1 in the first path, and the first path is not released.

[0209] Step 515: UDM sends a registration response to AMF 2.

[0210] Step 516: AMF2 sends a Registration Accept message to the UE through RAN2.

[0211] The UE receives the registration acceptance message and considers that the registration over the second path is successful, and can then access the network over the second path.

[0212] After the registration of the second path is completed, the UE accesses the same network through the first path and the second path at the same time, and the access types corresponding to the first path and the second path are 3GPP access types.

[0213] Through the steps of method 500, in a dual-connection scenario, the UE sends indication information of selecting different AMFs to RAN2, so that RAN2 selects an AMF different from the first path, so that the different AMFs respectively maintain an N2 connection for the UE, and the UE can access the same network through two different paths for two different AMFs.

[0214] The following describes, in conjunction with FIG6 , a method 600 for a communication device to simultaneously access the same network via two paths, provided by an embodiment of the present application. The communication device may be a terminal device (e.g., UE 110 in FIG1 ), or a chip (system) that may be provided within the terminal device. In other words, method 600 may be performed by the terminal device, or by a chip (system) within the terminal device.

[0215] The communication method flow diagram shown in FIG6 may include the following steps:

[0216] Step 601: A communication device accesses a network via a first path connecting a first radio access network device and a first access and mobility management network element.

[0217] It should be noted that before accessing the network, the communication device registers with the network via a first path connecting the first radio access network device and the first access and mobility management network element. During the registration process, the first access and mobility management network element establishes a connection for the communication device along the first path with the first radio access network device, illustratively, an N2 connection. Once registration is successful, it can be understood that the communication device can access the network via the first path.

[0218] For a description of the communication device registering through the first path, reference may be made to step 501 .

[0219] In one possible implementation, before the communication device accesses the network through the first path, the communication device obtains identification information of the first access and mobility management network element. Exemplarily, the identification information of the first access and mobility management network element may be 5G-GUTI, GUAMI, or 5G-S-TMSI.

[0220] In a possible implementation manner, the communication device receives a registration acceptance message from the first access and mobility management network element through a first path, where the registration acceptance message includes identification information of the first access and mobility management network element.

[0221] Step 602: The communication device sends a request message.

[0222] The request message is used to request that the communication device be registered with the network. The request message includes indication information, and the indication information is used for the second radio access network device to select a second access and mobility management network element that is different from the first access and mobility management network element.

[0223] It should be noted that before the communication device sends the request message, the communication device determines that it wishes to access the network simultaneously via two different paths, and the communication device determines that it has already accessed the network via the first path. Exemplarily, the communication device may determine that it wishes to access the network via two paths based on the multi-connection information. For a description of multi-connection, please refer to step 510.

[0224] In a possible implementation, the indication information may not be included in the request message, and the communication device may send the indication message to the second radio access network device through a separate message during the process of registering with the network through the second radio access network device.

[0225] In one possible implementation, the indication information indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths connect two different radio access network devices and two different access and mobility management network elements, respectively. Alternatively, the indication information indicates selection of different access and mobility management network elements.

[0226] In one possible implementation, the indication information is the SUCI of the communication device. It will be understood that the SUCI may implicitly indicate that the communication device supports simultaneous network access through two different paths, or implicitly indicate that the communication device wishes to simultaneously access the network through two different paths, indicating selection of different access and mobility management network elements. Exemplarily, the AN parameter in the AN message includes the SUCI and identification information of the first access and mobility management network element. Therefore, the AN message received by the second radio access network device includes the SUCI and identification information of the first access and mobility management network element. The second radio access network device can determine, based on the identification information of the first access and mobility management network element, that the communication device is not performing initial registration, but has sent the SUCI, and therefore can determine that the communication device wishes to access the network through dual connectivity.

[0227] In one possible implementation, the request message is an AN message. The communication device sends an AN message to the second radio access network device. The AN message is used to request that the communication device be registered with the network. The AN message includes instruction information. For ease of description, this embodiment is described using the AN message as an example.

[0228] In a possible implementation, the AN message includes AN parameters, and the AN parameters include indication information.

[0229] In another possible implementation, the indication information is a field in the AN message that can be parsed by the radio access network device. Exemplarily, the field can exist in the AN message in parallel with the AN parameters and the registration request message.

[0230] Optionally, the communication device further transmits identification information of the first access and mobility management network element. Exemplarily, the communication device transmits an access network AN message to the second radio access network device, further including identification information of the first access and mobility management network element. In one possible implementation, the AN message includes AN parameters, which include indication information and identification information of the first access and mobility management network element.

[0231] Step 603: The second radio access network device obtains identification information and instruction information of the first access and mobility management network element.

[0232] In one possible implementation, a second radio access network device receives a request message from a communication device, the request message including identification information and indication information of a first access and mobility management network element. Exemplarily, the second radio access network device receives an AN message from the communication device, the AN message being used to request registration of the communication device with the network, the AN message including identification information and indication information of the first access and mobility management network element. Furthermore, AN parameters in the AN message include identification information and indication information of the first access and mobility management network element.

[0233] In another possible implementation, the second radio access network device receives indication information from the communication device and receives identification information of the first access and mobility management network element from the core network or the first radio access network device. For example, the UDM in the core network. Exemplarily, the second radio access network device receives an AN message from the communication device, the AN message including the indication information. Based on the indication information, the second radio access network device requests information about the communication device on the first path, such as identification information of the first access and mobility management network element, from the core network or the first radio access network device. The second radio access network device then receives the identification information of the first access and mobility management network element.

[0234] Step 604: The second radio access network device selects a second access and mobility management network element that is different from the first access and mobility management network element.

[0235] In a possible implementation manner, the second radio access network device selects a second access and mobility management network element different from the first access and mobility management network element according to the identification information and indication information of the first access and mobility management network element.

[0236] Step 605: The second radio access network device sends a registration request message to the second access and mobility management network element.

[0237] In one possible implementation, the AN message includes AN parameters and a registration request message, and the second radio access network device sends the registration request message to the second access and mobility management network element. The registration request message is used to request that the communication device be registered with the network via a second path connecting the second access and mobility management network element and the second radio access network device.

[0238] Step 606: The communication device accesses the network through a second path connecting the second radio access network device and the second access and mobility management network element.

[0239] It should be noted that the second access and mobility management network element sends a registration acceptance message to the communication device through the second radio access network device. The communication device receives the registration acceptance message and considers that the registration is successful over the second path, and can then access the network through the second path.

[0240] After the registration of the second path is completed, the communication device accesses the same network through the first path and the second path at the same time, and the access types corresponding to the first path and the second path are 3GPP access types.

[0241] It should be noted that accessing the same network through the first path and the second path at the same time does not mean that the communication device must send or receive data through the two paths at the same time, but rather means that the communication device can access the network and send or receive data through the first path, and can also access the network and send or receive data through the second path.

[0242] Through the steps of method 600, in a dual-connection scenario, the communication device sends instruction information for selecting different access and mobility management network elements to the second radio access network device through the communication device, so that the second radio access network device selects an access and mobility management network element different from that in the first path, so that the different access and mobility management network elements respectively maintain an N2 connection for the communication device, and then the communication device can access the same network through two different paths for two different access and mobility management network elements.

[0243] As shown in FIG7 , a method 700 applicable to the present application is introduced. Through method 700, a UE can access the same network through dual connectivity. Dual connectivity is two connections of the 3GPP access type, corresponding to two paths of different radio access network devices. The method includes the following steps:

[0244] Step 701: The UE accesses the network through a first path connecting RAN1 and AMF1.

[0245] For the related description, please refer to the related description in step 501 in FIG5 , which will not be repeated here.

[0246] Step 710: The UE sends an AN message to RAN2.

[0247] In one possible implementation, the AN message includes AN parameters and a registration request message. The registration request message includes information for generating a different UE context for the second path than the first path. This embodiment uses the SUCI carried in the registration request message as an example, where the information for generating a different UE context for the second path than the first path is SUCI. That is, the UE identifier carried in the registration request message is SUCI. It is understood that although the UE obtains the 5G-GUTI assigned by AMF1 via the first path, the UE identifier used in the registration request sent by the UE is SUCI. Optionally, the registration type is initial registration. It should be noted that the AN parameters may include identification information of the AMF in the first path, such as GUAMI, 5G-S-TMSI, or 5G-GUTI. In other words, RAN2 is allowed to select the previous AMF, i.e., AMF1, based on the AMF's identification information. When the UE identifier in the registration request message is SUCI, even if the same AMF is selected, the AMF will treat it as a new UE and establish a new connection.

[0248] Optionally, the AN message includes dual-diversion indication information, and the dual-diversion indication information is used by the UDM to save two sets of contexts for the UE. Exemplarily, the dual-diversion indication information indicates that the UE is in a dual-connection state, or indicates that two sets of contexts are saved. The dual-diversion indication information can be carried in the AN parameters in the AN message or in the registration request message, or exist in parallel with the AN parameters and the registration request message in the AN message. The AN parameters include the dual-diversion indication information, and RAN2 can obtain the dual-diversion indication information and send it to the AMF through the N2 message. The registration request message includes the dual-diversion indication information, and the dual-diversion indication information can be a field in the registration type. For example, the dual-diversion indication information is a newly added registration type. The exemplary name of the newly added registration type can be DualSteer Registration. The name is not limited here. The registration type is DualSteer Registration, which is used to indicate to the network that the registration is for the second path of dual-connection registration for the UE. When the dual-diversion indication information exists in parallel with the AN parameters and the registration request message in the AN message, both RAN and AMF can parse the dual-diversion indication information.

[0249] It should be noted that when the UE determines that it wishes to access the network simultaneously via two different paths, step 710 is executed. Exemplarily, before the UE sends the AN message, the UE determines that it can access the network via two paths, and the UE determines that it has already accessed the network via the first path. Exemplarily, the UE can determine that it can access the network via two paths based on the multi-connection information. For a description of multi-connection, please refer to step 510 in Figure 5.

[0250] Step 711: RAN2 selects AMF.

[0251] In one possible implementation, for the case where the Registration Request message includes SUCI, if the Registration Request message in the AN message does not include the AMF identification information (such as GUAMI or 5G-S-TMSI), RAN2 selects an appropriate AMF by referring to step 202 in Figure 2 when performing AMF selection. It should be noted that the RAN cannot parse the content of the Registration Request message, so the RAN selection of the AMF is independent of whether the Registration Request message carries the AMF identification information. The RAN selects the AMF based on the information in the AN parameters.

[0252] It should be noted that, in this embodiment, the AMF selected by RAN2 can be AMF1 in the first path, or it can be AMF2 which is different from AMF1. In this embodiment, RAN2 selects AMF1 and the path connecting RAN2 and AMF1 is the second path as an example for description.

[0253] Step 712: RAN2 sends a registration request message to AMF1.

[0254] In one possible implementation, when the registration request message includes SUCI, the UE identification information in the registration request message is SUCI (the SUCI included in the registration request message corresponding to the second path may be referred to as second SUCI hereinafter in this embodiment).

[0255] It should be noted that the identification information reported by the UE and obtained by the AMF here is the second SUCI, not the 5G-GUTI and other information obtained in the first path. Because the UE randomly generates a SUCI each time, the second SUCI sent by the UE in the second path differs from the first SUCI sent in the first path. Therefore, the AMF cannot associate the UE's UE context with the first path using the UE's identification information, i.e., the second SUCI. In other words, based on the second SUCI, the AMF1 will consider the UE to be a different UE from the UE in the first path. Therefore, after completing step 713 below, a second UE context will be created for the UE.

[0256] Optionally, the registration request message also includes dual-split indication information.

[0257] Step 713: AMF triggers the authentication and security procedure with the UE, AUSF, and UDM.

[0258] For related descriptions, please refer to the relevant instructions in the above step 204, which will not be repeated here.

[0259] As described above, since AMF1 considers the UE to be a different UE from the UE of the first path based on the second SUCI, it creates a second UE context for the UE after completing the authentication and security process.

[0260] It should be noted that during the authentication and security process, the AMF sends a second SUCI to the UDM via the AUSF. The UDM decrypts the second SUCI to obtain the UE's SUPI. There is only one SUPI for the subscription data of a single UE, for example, one SUPI per SIM card, but there may be multiple SUCIs after the encrypted SUPI.

[0261] Step 714: AMF1 sends a registration request to UDM.

[0262] This registration request is used by AMF 1 to register with UDM as the AMF serving the UE, and AMF 1 to register the UE context with UDM.

[0263] In one possible implementation, the registration request also includes dual-split indication information. After the UDM obtains the dual-split indication information, the UDM saves two contexts for the UE. It is understood that when the UDM saves the second context for the same UE, it does not send a deregistration request to AMF1 in the first path, and the first path is not released.

[0264] In another possible implementation, the UDM may decrypt the SUPI based on the second SUCI transmitted by the UE via the second path, determine that the UE accesses the network via two paths based on the same UE identifier SUPI of the first path and the second path, and thus save the second UE context for the UE. Exemplarily, the UE context saved by the UDM is sent to the UDM by AMF1.

[0265] Step 715: UDM sends a registration response to AMF 1.

[0266] Step 716: AMF1 sends a registration accept message to the UE through RAN2.

[0267] The UE receives the registration acceptance message and considers that the registration over the second path is successful, and can then access the network over the second path.

[0268] After the registration of the second path is completed, the UE accesses the same network through the first path and the second path at the same time, and the access types corresponding to the first path and the second path are 3GPP access types.

[0269] It should be noted that in the above step 711, if RAN2 selects AMF2 which is different from AMF1, the subsequent steps refer to steps 512-516 in Figure 5. Thus, AMF2 and AMF1 each maintain an N2 connection for the UE, and the UE can access the same network through two different paths for two different AMFs.

[0270] Through the steps of method 700, in a dual-connectivity scenario, the UE includes information (e.g., SUCI) used to generate a UE context for the second path that is different from the first path in a registration request message to be sent to the AMF. Therefore, even if the RAN on the second path selects the same AMF as the first path, the AMF considers it to be another UE based on this information and creates a new UE context for the UE. As a result, the AMF retains two N2 connections through two sets of UE contexts, and the UE can access the same network through different paths corresponding to the two N2 connections to the same AMF.

[0271] The following describes, in conjunction with FIG8 , a method 800 for a communication device to simultaneously access the same network via two paths, provided by an embodiment of the present application. The communication device may be a terminal device (e.g., UE 110 in FIG1 ), or a chip (system) that may be provided within the terminal device. In other words, method 800 may be performed by the terminal device, or by a chip (system) within the terminal device.

[0272] The communication method flow diagram shown in FIG8 may include the following steps:

[0273] Step 801: A communication device accesses a network via a first path connecting a first radio access network device and a first access and mobility management network element.

[0274] It should be noted that before accessing the network, the communication device registers with the network via a first path connecting the first radio access network device and the first access and mobility management network element. During the registration process, the first access and mobility management network element establishes a connection with the first radio access network device over the first path, exemplarily an N2 connection. Upon successful registration, it can be understood that the communication device can access the network via the first path.

[0275] For a description of the communication device registering through the first path, reference may be made to step 501 in method 500 .

[0276] In one possible implementation, before the communication device accesses the network through the first path, the communication device obtains identification information of the first access and mobility management network element. Exemplarily, the identification information of the first access and mobility management network element may be 5G-GUTI, GUAMI, or 5G-S-TMSI.

[0277] In a possible implementation manner, the communication device receives a registration acceptance message from the first access and mobility management network element through a first path, where the registration acceptance message includes identification information of the first access and mobility management network element.

[0278] Step 802: The communication device sends a request message.

[0279] The request message is used to request that the communication device be registered with the network, and the request message includes information for an access and mobility management network element to generate a context for the communication device that is different from the first path. It should be noted that the access and mobility management network element may be the first access and mobility management network element in the first path, or a second access and mobility management network element that is different from the first access and mobility management network element.

[0280] It should be noted that before the communication device sends the request message, the communication device determines that it wishes to access the network simultaneously via two different paths, and the communication device determines that it has already accessed the network via the first path. Exemplarily, the communication device may determine that it wishes to access the network via two paths based on the multi-connection information. For a description of multi-connection, please refer to step 510.

[0281] In one possible implementation, the request message is an AN message. The communication device sends an AN message to the second radio access network device, the AN message being used to request that the communication device be registered with the network, the AN message including information for the access and mobility management network element to generate a context for the communication device that is different from the first path.

[0282] In one possible implementation, information used by the access and mobility management network element to generate a context for a communication device that is different from the first path is included in a field in an AN message that the access and mobility management network element can parse. For example, the information can be included in the AN message alongside AN parameters and a registration request message. For another example, the AN message includes a registration request message, which includes information used by the access and mobility management network element to generate a context for a communication device that is different from the first path. Furthermore, the second radio access network device sends the registration request message to the second access and mobility management network element.

[0283] In a possible implementation manner, the communication apparatus sends a request message to the second access and mobility management network element through the second radio access network device, where the request message is a registration request message.

[0284] In another possible implementation, the information used to access and mobility management network elements to generate the context of a communication device that is different from the first path may not be in the request message. During the process of the communication device registering to the network through the second radio access network device, the information used to access and mobility management network elements to generate the context of a communication device that is different from the first path may be sent to the second radio access network device through a separate message.

[0285] In one possible implementation, the information used by the access and mobility management network element to generate a context for a communication device that is different from the first path indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements. Alternatively, the information used by the access and mobility management network element to generate a context for a communication device that is different from the first path indicates creation of a context for the trusted device.

[0286] In one possible implementation, the information used by the access and mobility management network element to generate a context for a communication device different from the first path is SUCI, i.e., the communication device identifier carried in the registration request message is SUCI. It will be understood that although the communication device here has a 5G-GUTI assigned by the first access and mobility management network element, the communication device identifier used in the registration request message sent by the communication device is SUCI, and optionally, the registration type is initial registration. Therefore, the second access and mobility management network element cannot associate the context of the communication device with the communication device identifier information, i.e., SUCI. Based on the SUCI, the second access and mobility management network element will deem the communication device to be a different communication device from the communication device of the first path, and therefore will create a second communication device context for the communication device.

[0287] In one possible implementation, a communications device initially registers with a network using a first SUCI. The communications device may register with the network via the first path through this initial registration process, or may register with the network via the first path through another non-initial registration process. However, regardless of whether the first path corresponds to the initial registration process, the second SUCI used to register with the network via the second path is different from the first SUCI used for the initial registration.

[0288] It should be noted that the communication device may encrypt the SUPI to obtain the SUCI. The SUCI obtained by the communication device for each encryption of the same SUPI may be different, for example, one encryption may produce a first SUCI and another encryption may produce a second SUCI. However, the SUPI obtained after subsequent decryption of the first SUCI and the second SUCI is the same.

[0289] In a possible implementation manner, before the communication apparatus sends the request message to the second radio access network device, the communication apparatus generates a second SUCI.

[0290] In one possible implementation, the communications device generates a second SUCI based on information indicating that the communications device desires to access the network simultaneously via two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements. In other words, only after the communications device determines that it desires to access the network simultaneously via two different paths will it generate another SUCI during the registration process with the network via the second path, causing the network to interpret this as a registration process for another UE.

[0291] Step 803: The access and mobility management network element creates a context for the communication device.

[0292] The access and mobility management network element can be the first access and mobility management network element in the first path, or it can be a second access and mobility management network element different from the first access and mobility management network element. The access and mobility management network element creates a context of the communication device for the communication device based on information used for the access and mobility management network element to generate a context of the communication device different from the first path.

[0293] This embodiment is described by taking the SUCI as an example, in which the access and mobility management network element generates the context information of the communication device different from the first path. There are the following two cases:

[0294] 1. When the access and mobility management network element is the first access and mobility management network element in a first path, the first access and mobility management network element has already created a first set of communication device contexts for the communication device for the first path, the first set of contexts including N2 connection information between the first access and mobility management network element and the first radio access network device. Subsequently, when receiving a SUCI of the communication device from a second radio access network device, because the SUCI sent by the communication device in the second path is different from the SUCI sent in the first path, the access and mobility management network element determines that the communication device is different from the communication device in the first path based on the different SUCIs. Therefore, the access and mobility management network element creates a second set of communication device contexts for the communication device, the second set of contexts including N2 connection information between the access and mobility management network element and the second radio access network device.

[0295] 2. When the access and mobility management network element is a second access and mobility management network element different from the first access and mobility management network element, the second access and mobility management network element creates a context for the communication device. The second access and mobility management network element determines, based on the received SUCI, that it does not have a context for the communication device, and therefore creates a communication device context for the communication device.

[0296] Step 804: The communication device accesses the network through a second path connecting the second radio access network device and the access and mobility management network element.

[0297] It should be noted that the access and mobility management network element sends a registration acceptance message to the communication device through the second radio access network device. The communication device receives the registration acceptance message and considers that the registration is successful over the second path, and can then access the network through the second path.

[0298] After the registration of the second path is completed, the communication device accesses the same network through the first path and the second path at the same time, and the access types corresponding to the first path and the second path are 3GPP access types.

[0299] Through the steps of method 800, in a dual-connectivity scenario, the communication device sends information to the access and mobility management network element, which is used by the communication device to generate a communication device context for the access and mobility management network element that is different from the first path. Therefore, even if the access and mobility management network element on the second path is the same as the first path, the access and mobility management network element considers it to be another communication device based on the information, and thus creates a new communication device context for the communication device. Therefore, when the same access and mobility management network element is used in both paths, the access and mobility management network element retains two N2 connections using two sets of communication device contexts. Consequently, the communication device can access the same network through two different paths to the same access and mobility management network element.

[0300] As shown in FIG9 , a method 900 applicable to the present application is introduced. Through the method 900, a UE can access the same network through dual connectivity. Dual connectivity is two connections of the 3GPP access type, corresponding to two paths of different radio access network devices. The method includes the following steps:

[0301] Step 901: The UE accesses the network through a first path connecting RAN1 and AMF1.

[0302] For the related description, please refer to the related description in step 501 in FIG5 , which will not be repeated here.

[0303] Step 910: The UE sends an AN message to RAN2.

[0304] In a possible implementation, the AN message includes indication information, where the indication information is used to retain the connection of the first path when establishing the connection of the second path.

[0305] In one possible implementation, the registration request message in the AN message includes indication information, for example, the indication information is a newly added registration type, and the indication information is a field in the registration type. Exemplarily, the name of the newly added registration type can be DualSteer Registration. The name is not limited here. The registration type is DualSteer Registration, which is used to indicate to the network that the registration is a second path for dual-connection registration for the UE.

[0306] In another possible implementation, the registration request message includes an additional indication information, which indicates to the network that the UE is registering the second path for dual connectivity at this time. At this time, the registration type of the UE may be an initial registration. The AMF determines that the registration type of the UE is an initial registration, and according to the indication information of the UE, it can be determined that the registration is for the UE to perform dual connectivity registration for the second path.

[0307] It should be noted that when the UE determines that it wishes to access the network simultaneously via two different paths, step 910 is executed. Exemplarily, before the UE sends the AN message, the UE determines that it can access the network via two paths, and the UE determines that it has already accessed the network via the first path. Exemplarily, the UE can determine that it can access the network via two paths based on the multi-connection information. For a description of multi-connection, please refer to step 510 in Figure 5.

[0308] Step 911: RAN2 selects AMF.

[0309] In a possible implementation, RAN2 selects a suitable AMF by referring to step 202 in FIG. 2 when performing AMF selection.

[0310] In another possible implementation, RAN2 may consider whether the AMF supports dual connectivity when selecting an AMF. An AMF that supports dual connectivity can be understood as one that can maintain two connection paths for the same UE, or as one that maintains a connection with the UE via two paths simultaneously. The indication information is a field in the AN message that the RAN can parse, such as in the AN parameters, or it may be present in the AN message alongside the AN parameters and the registration request message. RAN2 selects an AMF that supports dual connectivity based on the indication information. Since the UE obtained the 5G-GUTI assigned by AMF1 during its first registration, the UE can obtain AMF1's identification information based on the 5G-GUTI. During its second registration, the UE can include AMF1's identification information (e.g., GUAMI or 5G-S-TMSI) in the AN parameters. RAN2 then determines whether AMF1 supports dual connectivity based on the indication information and AMF1's identification information. It should be noted that the RAN stores information about whether the AMF supports dual connectivity. For example, the RAN determines AMF1's capability information based on AMF1's identification information, thereby determining whether AMF1 supports dual connectivity. RAN2 selects AMF in the following two situations:

[0311] Case 1: If AMF1 supports maintaining two N2 connections for the same UE at the same time and RAN2 can access it, RAN2 selects AMF1 to serve the UE.

[0312] Case 2: If AMF1 does not support maintaining two N2 connections for the same UE at the same time, or RAN2 cannot connect to AMF1, for example, when the UE accesses from NTN, due to the large satellite coverage, RAN2's ground gateway station may be in a different area from AMF1. RAN2 and AMF1 cannot connect directly, so RAN2 will select AMF2, which is different from AMF1, according to its own area.

[0313] For the second scenario, the subsequent steps of RAN2 selecting AMF2 different from AMF1 may refer to steps 512-516 in method 500, which will not be repeated here.

[0314] In this embodiment, RAN2 selects AMF1, and the path connecting RAN2 and AMF1 is the second path.

[0315] Step 912: RAN2 sends a registration request message to AMF1.

[0316] The registration request message includes 5G-GUTI and indication information. Among them, 5G-GUTI is obtained by the UE on the first path and is used by the AMF to associate the UE context created when the UE registers from the first path. The indication information is used to instruct the AMF that the second path is used for the UE to achieve dual connectivity, and there is no need to replace the connection of the UE's first path, or to indicate that the UE supports dual connectivity, or to indicate that the UE wishes to access the network through dual connectivity, or to indicate that the connection of the first path is retained when the connection of the second path is established.

[0317] The registration request message in step 912 is the second registration request message received by AMF1 for the same UE. AMF1 determines the UE context of the UE based on the 5G-GUTI of the UE in the registration request message, and adds the information of the N2 connection of the second path to the UE context information. It can be understood that the UE context includes information about the N2 connection of the first path and the second path for the UE, that is, the AMF can retain two N2 connections for the same UE, and it can also be understood that the AMF maintains the N2 connection with the communication device through two paths at the same time.

[0318] In a possible implementation, RAN2 sends an NGAP message, also referred to as an N2 message, to AMF1, wherein the N2 message includes the registration request message.

[0319] Step 913 (optional): AMF triggers the authentication and security procedure with the UE, AUSF, and UDM.

[0320] For related descriptions, please refer to the relevant instructions in the above step 204, which will not be repeated here.

[0321] It should be noted that, when RAN2 selects AMF1 in step 911, step 913 can be skipped. When RAN2 selects AMF2 which is different from AMF1, step 913 is executed.

[0322] Step 914: AMF1 sends a registration request to UDM.

[0323] Step 915: UDM sends a registration response to AMF 1.

[0324] Step 916: AMF1 sends a registration accept message to the UE through RAN2.

[0325] For steps 914-916, refer to the relevant description of steps 714-716 in the above method 700 and will not be repeated here.

[0326] The following describes, in conjunction with FIG10 , a method 1000 for enabling a communication device to simultaneously access the same network via two paths, as provided in an embodiment of the present application. The communication device may be a terminal device (e.g., UE 110 in FIG1 ), or a chip (system) within the terminal device. In other words, method 1000 may be executed by the terminal device, or by a chip (system) within the terminal device.

[0327] The communication method flow diagram shown in FIG10 may include the following steps:

[0328] Step 1001: A communication device accesses a network via a first path connecting a first radio access network device and a first access and mobility management network element.

[0329] It should be noted that before accessing the network, the communication device registers with the network via a first path connecting the first radio access network device and the first access and mobility management network element. During the registration process, the first access and mobility management network element establishes a connection with the first radio access network device over the first path, exemplarily an N2 connection. Upon successful registration, it can be understood that the communication device can access the network via the first path.

[0330] For a description of the communication device registering through the first path, reference may be made to step 501 .

[0331] In one possible implementation, before the communication device accesses the network through the first path, the communication device obtains identification information of the first access and mobility management network element. Exemplarily, the identification information of the first access and mobility management network element may be 5G-GUTI, GUAMI, or 5G-S-TMSI.

[0332] In a possible implementation manner, the communication device receives a registration acceptance message from the first access and mobility management network element through a first path, where the registration acceptance message includes identification information of the first access and mobility management network element.

[0333] In one possible implementation, during a process in which a communications device registers with a network via a first path connecting a first radio access network device and a first access and mobility management network element, the communications device sends an AN message to the first radio access network device, where the AN message includes indication information. The indication information indicates that the communications device supports dual connectivity, indicates that the communications device desires to access the network via the dual connectivity, or indicates that a connection via the first path is retained while a connection via the second path is established.

[0334] In one possible implementation, the indication information is a field in the AN message that the first radio access network device can parse. Exemplarily, the indication information can be in an AN parameter, or in the AN message, in parallel with the AN parameter and the registration request message. The first radio access network device selects an access and mobility management network element that supports dual connectivity based on the indication information.

[0335] In one possible implementation, during the process of the communication device accessing the network through the first path, the communication device sends information to the first wireless access network that the communication device supports dual connectivity. The first wireless access network device selects an access and mobility management network element that supports dual connectivity based on the information, and subsequently executes steps 203-207 in Figure 2. The communication device thereby completes the registration process and can access the network through the first path.

[0336] Step 1002: The communication device sends a request message.

[0337] The request message is used to request that the communication device be registered with the network. The request message includes instruction information, and the instruction information is used to retain the connection of the first path when establishing the connection of the second path.

[0338] It should be noted that before the communication device sends the request information, the communication device determines that it can access the network via two paths, and the communication device determines that it has already accessed the network via the first path. Exemplarily, the communication device can determine that it can access the network via two paths based on the multi-connection information. For a description of multi-connection, please refer to step 510 in Figure 5.

[0339] In a possible implementation, the indication information may not be included in the request message. During the process of the communication device registering with the network through the second radio access network device, the indication information may be sent to the second radio access network device through a separate message.

[0340] The communication device sends the instruction information to the access and mobility management network element through the second radio access network device. It should be noted that the access and mobility management network element can be the first access and mobility management network element in the first path, or it can be a second access and mobility management network element different from the first access and mobility management network element.

[0341] In one possible implementation, the indication information indicates that the communication device supports simultaneous network access via two different paths, or indicates that the communication device desires to simultaneously access the network via two different paths, where the two different paths respectively connect two different radio access network devices and two identical or different access and mobility management network elements. Alternatively, the indication information indicates that the connection via the first path is retained while establishing a connection via the second path.

[0342] In one possible implementation, the request message is an AN message. The communication device sends an access network AN message to the second radio access network device. The AN message is used to request that the communication device be registered with the network, and the AN message includes indication information. For example, the AN message includes a registration request message, and the registration request message includes the indication information. Exemplarily, the second radio access network device sends the registration request message to an access and mobility management network element. For another example, the indication information is a field in the AN message that can be parsed by the access and mobility management network element. Exemplarily, the indication information may be present in the AN message alongside AN parameters and the registration request message.

[0343] In one possible implementation, the registration request message includes a registration type. The indication information is a field in the registration type. Exemplarily, the field in the registration type is DualSteer Registration, which can be understood as a new registration type (not limited to the name). The DualSteer Registration registration type indicates that the registration is for a second dual-connectivity registration path for the communication device.

[0344] In another possible implementation, the communication device sends a request message to the second access and mobility management network element through the second radio access network device, where the request message is a registration request message, and the registration request message includes indication information.

[0345] In a possible implementation, the indication information may not be included in the request message. During the process of the communication device registering with the network through the second radio access network device, the indication information may be sent to the second radio access network device through a separate message.

[0346] Step 1003 (optional): The second radio access network device selects an access and mobility management network element that supports dual connectivity.

[0347] It should be noted that the access and mobility management network element that supports dual connectivity can be understood as the access and mobility management network element being able to reserve two path connections for the same communication device, or it can be understood as the access and mobility management network element maintaining a connection with the communication device through two paths at the same time.

[0348] In one possible implementation, the second radio access network device selects an access and mobility management network element that supports dual connectivity based on the indication information. It should be noted that in this case, the indication information also needs to be a field in the AN message that the second radio access network device can parse. For example, the indication information can be in an AN parameter, or in the AN message, in parallel with the AN parameter and the registration request message.

[0349] In one possible implementation, a second radio access network device determines whether the first access and mobility management network element supports dual connectivity based on identification information and indication information of the first access and mobility management network element. If the first access and mobility management network element supports dual connectivity, the second radio access network device selects the first access and mobility management network element to access the network. Alternatively, if the first access and mobility management network element does not support dual connectivity, the second radio access network device selects a second access and mobility management network element different from the first access and mobility management network element to access the network.

[0350] In another possible implementation, in step 1001, the first radio access network device of the first path selects a first access and mobility management network element that supports dual connectivity based on the indication information. Therefore, the second radio access network device selects the first access and mobility management network element based on the identification information of the first access and mobility management network element.

[0351] It should be noted that step 1003 is optional. When step 1003 is not performed, the second radio access network device selects the access and mobility management network element, as shown in step 202 in FIG. 2 .

[0352] Step 1004: The second radio access network device sends a registration request message to the access and mobility management network element.

[0353] In one possible implementation, the AN message includes AN parameters and a registration request message, and the registration request message includes indication information. The second radio access network device sends the registration request message to the access and mobility management network element. The registration request message is used to request that the communication device be registered with the network via a second path connecting the access and mobility management network element and the second radio access network device.

[0354] It should be noted that the access and mobility management network element may be a first access and mobility management network element or a second access and mobility management network element.

[0355] Step 1005: The access and mobility management network element establishes a connection with the second radio access network device.

[0356] The access and mobility management network element may be the first access and mobility management network element in the first path, or may be a second access and mobility management network element different from the first access and mobility management network element. Therefore, there are the following two situations:

[0357] 1. When the access and mobility management network element is the first access and mobility management network element in a first path, the first access and mobility management network element has already established a connection for the communication device along the first path between the first access and mobility management network element and a first radio access network device. Subsequently, upon receiving instruction information from a second access and mobility management network element, the first access and mobility management network element establishes a connection for the communication device along the second path between the first access and mobility management network element and the second radio access network device according to the instruction information, while retaining the connection along the first path.

[0358] 2. When the access and mobility management network element is a second access and mobility management network element different from the first access and mobility management network element, the second access and mobility management network element establishes a connection with the second radio access network device.

[0359] In a possible implementation, the access and mobility management network element sends instruction information to the unified data management network element, where the instruction information is used by the unified data management network element to save two sets of contexts for the communication device.

[0360] Step 1006: The communication device accesses the network through a second path connecting the second radio access network device and the access and mobility management network element.

[0361] It should be noted that the access and mobility management network element sends a registration acceptance message to the communication device through the second radio access network device. The communication device receives the registration acceptance message and considers that the registration is successful in the second path, and can then access the network through this path.

[0362] After the registration of the second path is completed, the communication device accesses the same network through the first path and the second path at the same time, and the access types corresponding to the first path and the second path are 3GPP access types.

[0363] Through the steps of method 1000, in a dual-connectivity scenario, the communication device sends instruction information to the access and mobility management network element for retaining the connection of the first path while establishing a connection of the second path. Based on this information, the access and mobility management network element retains the connection of the first path while establishing a connection of the second path for the communication device. Thus, when the same access and mobility management network element is used in both paths, the access and mobility management network element retains the connections of the two paths respectively, and the communication device can access the same network through two different paths to the same access and mobility management network element.

[0364] 11, a method 1100 for a UE to obtain a RAT type during a registration process, provided in an embodiment of the present application, is described below. Method 1100 is applicable to situations where the AMFs in the first and second paths are different, such as in method 500, method 600, method 800, method 900, or method 1000 described above.

[0365] The communication method flow diagram shown in FIG11 may include the following steps:

[0366] Step 1101: The UE accesses the network through a first path connecting RAN1 and AMF1.

[0367] It should be noted that step 1101 may refer to steps 501 to 515 in the above method 500 .

[0368] Step 1102: AMF2 obtains first information.

[0369] The first information is used to determine whether the UE can access the network through the current path. Exemplarily, the first information indicates the type of radio access technology RAT that allows the UE to access the network, or the first information indicates a combination of RAT types that allow the UE to access the network through two paths. For example, if the first information is TN, the UE is allowed to access the network through TN. For another example, if the first information is a combination of RAT types on two paths: a terrestrial communication network and a non-terrestrial communication network, or 5G and 6G, etc., the UE is allowed to access the network through a TN path and an NTN path, or the UE is allowed to access the network through a 5G path and a 6G path.

[0370] In one possible implementation, the AMF obtains the first information from the UDM. For example, the AMF sends an indication message to the UDM, which indicates that the UE supports accessing the network through two different paths at the same time. The UDM can determine the first information of the UE based on the indication message and send the first information to AMF2. For another example, the UDM determines that the UE supports accessing the network through two different paths at the same time based on the UE's subscription data, and sends the first information to AMF2. For example, the first information is the RAT type that allows the UE to access the network, or a combination of RAT types that allow the UE to access the network through two paths, such as the combination of RAT types TN and NTN, or 5G and 6G, etc.

[0371] In another possible implementation, the AMF obtains the first information from the PCF. Exemplarily, the AMF sends an indication message to the PCF, where the indication message indicates that the UE supports accessing the network through two different paths at the same time. The PCF can determine the first information of the UE based on the indication message, and send the first information to AMF2. For another example, the PCF obtains the subscription data of the UE from the UDM, determines that the UE supports accessing the network through two different paths at the same time based on the subscription data of the UE, and sends the first information to AMF2. For example, the first information is the RAT type that allows the UE to access the network, or a combination of RAT types that allows the UE to access the network through two paths, such as the combination of RAT types of TN and NTN, or 5G and 6G, etc. Exemplarily, the AMF sends an access management (AM) policy request message to the PCF, and the AM policy request message includes the indication information. The PCF replies to the AMF with the AM policy, and the AM policy includes the first information.

[0372] In one possible implementation, the UDM or PCF determines the first information based on the indication information and the RAT type of the first path. For example, the UDM or PCF determines that the combination of RAT types allowed to be accessed by the UE is 5G and 6G, and the UDM or PCF determines that the RAT type of the first path is 5G, thereby determining that the first information is 6G, i.e., the RAT type allowed to access the network through the second path of the UE is 6G.

[0373] Step 1103: AMF2 determines whether the UE is allowed to access.

[0374] In one possible implementation, AMF2 determines whether the UE meets the requirements of the first information based on the RAT type currently accessed by the UE, thereby determining whether to allow the UE to access. It should be noted that the determination of whether to allow the UE to access here refers to whether the UE is allowed to access the network through dual connectivity. In other words, if the UE does not meet the requirements of the first information, it can still access the network through a single connection in the prior art.

[0375] In one possible implementation, when the first information is the RAT type that allows the UE to access the network, AMF2 determines whether the first information includes the RAT type corresponding to the second path. For example, the first information allows the UE to access the network through 5G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. In this case, AMF2 can determine that the UE is not allowed to access. In another example, the first information allows the UE to access the network through 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. In this case, AMF2 can determine that the UE is allowed to access.

[0376] In another possible implementation, when the first information is a combination of RAT types that allow the UE to access the network, AMF2 determines whether the first information includes the RAT type corresponding to the UE accessing the network through the second path. For example, the first information allows the UE to access the network through a combination of 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 4G. In this case, AMF2 can determine that the UE is not allowed to access.

[0377] For example, the first information allows the UE to access the network through 5G and 6G. AMF2 only needs to determine whether the first information includes the RAT type corresponding to the second path. When the RAT type corresponding to the second path is 5G or 6G, AMF2 can determine that the UE is allowed to access the network through the second path. When the RAT type corresponding to the second path is 4G, AMF2 can determine that the UE is not allowed to access the network through the second path.

[0378] Exemplarily, the first information allows the UE to access the network via a combination of TN and NTN. AMF2 on the second path and AMF1 on the first path are different AMFs. If the UE currently wishes to access the network via dual connectivity, and a UE context exists for the UE at both AMF1 and AMF2, the UDM can send information about the UE on the other side, AMF1, to AMF2. This AMF1 information can be the UE context. For example, the RAT type on the AMF1 side is TN. AMF2 compares the UE's RAT types on the two paths with the first information sent by the network side to determine whether the currently selected RAT type meets the network requirements. Exemplarily, the first information allows the UE to access the network via a combination of TN and NTN. AMF2 determines that the UE has selected TN on both paths, which clearly does not meet the network requirements, and can determine that the UE is not allowed access. Alternatively, AMF2 determines that the UE has selected TN on the first path and NTN on the second path, and can determine that the UE is allowed access.

[0379] In another example, the first information allows the UE to access the network via a combination of 5G and 6G. AMF2 and AMF1 are different AMFs. If the UE currently wishes to access the network via dual connectivity and a UE context exists for the UE at both AMF1 and AMF2, the UDM can send the UE's information about the other AMF1 to AMF2. This AMF1 information can be the UE context. For example, the RAT type on AMF1 is 5G. AMF2 compares the UE's RAT types on both paths with the first information sent by the network to determine whether the currently selected RAT type meets the network's requirements. For example, if the first information allows the UE to access the network via a combination of 5G and 6G, and AMF2 determines that the UE has selected 5G on both paths, this clearly does not meet the network's requirements, and the UE may be denied access. Alternatively, if the AMF2 determines that the UE has selected 5G on the first path and 6G on the second path, the UE may be allowed access. If the AMF2 determines that the UE is allowed access, step 1104a is executed.

[0380] If AMF2 determines that the UE is not allowed to access, it executes step 1104b to retain the previous first path or executes step 1104c to retain the newly established second path. Furthermore, AMF2 may also send the allowed RAT types to the UE, and the UE may subsequently select the corresponding RAT based on the RAT types allowed by the network. For example, if the allowed RAT type is NTN, the UE may select a cell with an NTN RAT type based on the RAT type carried in the cell's broadcast message.

[0381] Step 1104a: AMF 2 sends a registration accept message to the UE.

[0382] The registration acceptance message includes 5G-GUTI.

[0383] The UE receives the registration accept message and therefore believes that it can access the network through this path.

[0384] Step 1104b: AMF2 sends a registration reject message to the UE.

[0385] Optionally, the registration rejection message includes first information, where the first information is used to indicate a RAT type that allows the UE to access the network.

[0386] Step 1104c: AMF2 accepts the second path and releases the first path.

[0387] In one possible implementation, AMF2 sends a registration acceptance message of the second path to the UE through RAN2, and releases the first path for the UE to access the network through RAN1 and AMF1.

[0388] In a possible implementation manner, the registration acceptance message of the second path includes the first information.

[0389] It should be noted that AMF2 determines that UE is not allowed to access based on the combination of RAT types. One possible scenario is that the first information is to allow UE to access the network through a combination of 5G and 6G. The first path is of 5G RAT type, and the second path is also of 5G RAT type. Therefore, one of the paths can be retained. One possible implementation method is to retain the second path and release the first path. Therefore, AMF2 sends a registration reception message to the UE through RAN2 and releases the first path.

[0390] In a possible implementation, AMF2 may send a request message to UDM to release the first path, and then UDM releases the first path connecting AMF1 and RAN1.

[0391] Through the steps of method 1100, the AMF obtains the RAT type that the UE is allowed to access the network from the UDM or PCF, so that the AMF can determine whether the UE can access the network through the current path based on the RAT type of the current path and the RAT type that the UE is allowed to access the network, and sends the RAT type that the UE is allowed to access the network to the UE, so that the UE can access the network through the RAT type specified by the network. The network notifies the UE of the RAT type that is allowed to access the network, so that the UE selects an appropriate RAT type for access, avoids the UE selecting an inaccessible RAT, and increases the success rate of UE access.

[0392] 12, a method 1200 for a UE to obtain a RAT type during a registration process, provided in an embodiment of the present application, is described below. Method 1200 is applicable to situations where the AMF in the first path and the second path are the same, such as method 700, method 800, method 900, or method 1000 described above.

[0393] The communication method flow diagram shown in FIG12 may include the following steps:

[0394] Step 1201: The UE accesses the network through a first path connecting RAN1 and AMF1.

[0395] It should be noted that step 1201 may refer to steps 701 to 715 in the above method 700 , or steps 901 to 915 in the above method 900 .

[0396] Step 1202: AMF1 obtains first information.

[0397] For the related description of the first information, please refer to step 1102 and will not be repeated here.

[0398] In one possible implementation, the AMF obtains the first information from the UDM. For example, the AMF sends an indication message to the UDM, which indicates that the UE supports accessing the network through two different paths at the same time. The UDM can determine the first information of the UE based on the indication message and send the first information to AMF1. For another example, the UDM determines that the UE supports accessing the network through two different paths at the same time based on the UE's subscription data, and sends the first information to AMF1. For example, the first information is the RAT type that allows the UE to access the network, or a combination of RAT types that allow the UE to access the network through two paths, such as the combination of RAT types TN and NTN, or 5G and 6G, etc.

[0399] In another possible implementation, the AMF obtains the first information from the PCF. Exemplarily, the AMF sends an indication message to the PCF, where the indication message indicates that the UE supports accessing the network through two different paths at the same time. The PCF can determine the first information of the UE based on the indication message, and send the first information to AMF1. For another example, the PCF obtains the subscription data of the UE from the UDM, determines that the UE supports accessing the network through two different paths at the same time based on the subscription data of the UE, and sends the first information to AMF1. For example, the first information is the RAT type that allows the UE to access the network, or a combination of RAT types that allows the UE to access the network through two paths, such as the combination of RAT types of TN and NTN, or 5G and 6G, etc. Exemplarily, AMF1 sends an access management AM policy request message to the PCF, where the AM policy request message includes the indication information, and the PCF replies to the AM policy to AMF1, where the AM policy includes the first information.

[0400] In one possible implementation, the UDM or PCF determines the first information based on the indication information and the RAT type of the first path. For example, the UDM or PCF determines that the combination of RAT types allowed for UE access is 5G and 6G, and the UDM or PCF determines that the RAT type of the first path is 5G. Thus, the first information is determined to be 6G, meaning that the RAT type allowed for the UE to access the network through the second path is 6G. This can be understood as the UDM or PCF determining the RAT type allowed for the second path based on the information of the first path as the first information.

[0401] Step 1203: AMF1 determines whether the UE is allowed to access.

[0402] In one possible implementation, AMF1 determines whether the UE meets the requirements of the first information based on the RAT type currently accessed by the UE, thereby determining whether to allow the UE to access. It should be noted that the determination of whether to allow the UE to access here refers to whether to allow access to the network through dual connectivity. In other words, if the UE does not meet the requirements of the first information, it can still access the network through a single connection in the prior art.

[0403] In one possible implementation, when the first information is the RAT type that allows the UE to access the network, AMF1 determines whether the first information includes the RAT type corresponding to the second path. For example, the first information allows the UE to access the network through 5G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. In this case, AMF1 can determine that the UE is not allowed to access. In another example, the first information allows the UE to access the network through 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. In this case, AMF1 can determine that the UE is allowed to access.

[0404] In another possible implementation, when the first information is a combination of RAT types that allow the UE to access the network, AMF1 determines whether the first information includes the RAT type corresponding to the UE accessing the network through the second path. For example, if the first information allows the UE to access the network through a combination of 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 4G, AMF1 may determine that the UE is not allowed to access.

[0405] For example, if the first information allows the UE to access the network through 5G and 6G, AMF1 only needs to determine whether the first information includes the RAT type corresponding to the second path. When the RAT type corresponding to the second path is 5G or 6G, AMF1 can determine that the UE is allowed to access the network through the second path. When the RAT type corresponding to the second path is 4G, AMF1 can determine that the UE is not allowed to access the network through the second path.

[0406] Exemplarily, the above-mentioned first information is to allow the UE to access the network through a combination of TN and NTN. If the UE currently hopes to access the network through dual connectivity, since there are two UE contexts for the UE at the AMF, the AMF can directly compare the UE's RAT type on the two paths with the first information sent by the network side, and can determine whether the currently selected RAT type meets the network requirements. Exemplarily, the first information is to allow the UE to access the network through a combination of TN and NTN. AMF1 determines that the UE has selected TN on both paths. At this time, it is obvious that the requirements of the network side are not met, and it can be determined that the UE is not allowed to access. Alternatively, AMF1 determines that the UE has selected TN on the first path and NTN on the second path. At this time, it can be determined that the UE is allowed to access.

[0407] In another example, the above-mentioned first information is to allow the UE to access the network through a combination of 5G and 6G, and the second path and the first path are both AMF1. If the UE currently hopes to access the network through dual connection, since there are two UE contexts for the UE at the AMF, the AMF can directly compare the UE's RAT type on the two paths with the first information sent by the network side, and can determine whether the currently selected RAT type meets the network requirements. Exemplarily, the first information is to allow the UE to access the network through a combination of 5G and 6G. AMF1 determines that the UE has selected 5G on both paths. At this time, it is obvious that the requirements of the network side are not met, and it can be determined that the UE is not allowed to access. Alternatively, AMF1 determines that the UE has selected 5G on the first path and 6G on the second path. At this time, it can be determined that the UE is allowed to access.

[0408] When AMF2 determines that the UE is allowed to access, execute step 1204a.

[0409] If AMF2 determines that the UE is not allowed to access, it executes step 1204b to retain the previous first path or executes step 1204c to retain the newly established second path. Furthermore, AMF1 may also send the allowed RAT types to the UE, and the UE may subsequently select the corresponding RAT based on the RAT types allowed by the network. For example, if the allowed RAT type is NTN, the UE may select a cell with an NTN RAT type based on the RAT type carried in the cell's broadcast message.

[0410] Step 1204a: AMF 1 sends a registration accept message to the UE.

[0411] The registration acceptance message includes 5G-GUTI.

[0412] The UE receives the registration accept message and therefore believes that it can access the network through this path.

[0413] Step 1204b: AMF1 sends a registration reject message to the UE.

[0414] Optionally, the registration rejection message includes first information, where the first information is used to indicate a RAT type that allows the UE to access the network.

[0415] Step 1204c: AMF1 accepts the second path and releases the first path.

[0416] In one possible implementation, AMF1 sends a registration acceptance message of the second path to the UE through RAN2, and releases the first path for the UE to access the network through RAN1 and AMF1.

[0417] In a possible implementation manner, the registration acceptance message of the second path includes the first information.

[0418] It should be noted that AMF1 determines that UE is not allowed to access based on the combination of RAT types. One possible scenario is that the first information allows the UE to access the network through a combination of 5G and 6G. The first path is of 5G RAT type, and the second path is also of 5G RAT type. Therefore, one of the paths can be retained. One possible implementation method is to retain the second path and release the first path. Therefore, AMF1 sends a registration reception message to the UE through RAN2 and releases the first path.

[0419] Through the steps of method 1200, the AMF obtains the RAT type allowed for the UE to access the network from the UDM or PCF, so that the AMF can determine whether the UE can access the network through the current path based on the RAT type of the current path and the RAT type allowed for the UE to access the network, and sends the RAT type allowed for the UE to the UE, so that the UE can access the network through the RAT type specified by the network. The network notifies the UE of the RAT type allowed for network access, so that the UE selects a RAN with an appropriate RAT type to access the network, preventing the UE from selecting an inaccessible RAT and increasing the success rate of UE access.

[0420] 13 , a method 1300 for a UE to obtain a RAT type during a registration process, provided in an embodiment of the present application, is described below.

[0421] As shown in the flow chart of the communication method in Figure 13, in this example, the UE accesses the same network through dual connectivity. The dual connectivity is two connections of the 3GPP access type, corresponding to two paths of different radio access network devices. The difference from the above methods 1100 and 1200 is that the UE carries the indication information when registering through the first path, so that the AMF obtains the first information according to the indication information when the UE registers through the first path. The method 1300 may include the following steps:

[0422] Step 1301: The UE sends a registration request message to AMF1 through RAN1.

[0423] For related descriptions, please refer to the relevant instructions in the above steps 201-203, which will not be repeated here.

[0424] Optionally, the registration request message also includes indication information, where the indication information indicates that the UE supports dual connectivity, or indicates that the UE wishes to access the network via dual connectivity, or indicates that the connection of the first path is retained while establishing a connection of the second path. In this embodiment, the indication information is dual split indication information as an example for description.

[0425] In one possible implementation, the UE sends an AN message to RAN1, which includes AN parameters and a registration request message. RAN1 then sends the registration request message to the AMF. The AN parameters include dual-split indication information. RAN1 selects an AMF that supports dual connectivity based on the dual-split indication information. Supporting dual connectivity can be understood as enabling the AMF to retain two connection paths for the same communication device, or as maintaining a connection with the UE through two paths simultaneously.

[0426] It should be noted that, in this embodiment, the dual split indication information can also be replaced by dual connectivity capability information, which is used to let the network side know that the currently accessed UE has dual connectivity, and subsequently establish a second path connection for the UE to implement dual connectivity.

[0427] In one possible implementation, the UE may obtain dual-connection indication information based on a user operation instruction. For example, the user may turn on a dual-connection switch on the UE. Further, the UE may enter a dual-connection state based on the user operation instruction.

[0428] In another possible implementation, the UE may obtain the dual split indication information based on pre-configured information, for example, information indicating that the UE supports dual split may be pre-configured in the UE factory configuration.

[0429] In another possible implementation, the UE may obtain dual-split indication information based on the service. For example, the current path cannot meet the rate requirement of a certain video service, so the UE may determine to use multiple paths to access the network based on the service.

[0430] Step 1302: AMF1 triggers the authentication and security procedure with the UE, AUSF, and UDM.

[0431] For related descriptions, please refer to the relevant instructions in the above step 204, which will not be repeated here.

[0432] Step 1303: AMF1 sends a registration request message to UDM.

[0433] Optionally, the registration request message includes dual split indication information. The registration request message is used by AMF 1 to register with the UDM as the AMF serving the UE.

[0434] In a possible implementation, after obtaining the dual split indication information from the registration request message, the UDM determines that two different UE contexts can be saved for the UE in the UDM, and saves the first UE context for the UE.

[0435] In another possible implementation, the registration request message does not include dual-split indication information. After the UDM obtains the UE identifier from the registration request, it can obtain the UE's subscription data. According to the dual-split capability information in the UE subscription data, it is determined that two different UE contexts can be saved for the UE in the UDM, and the first UE context is saved for the UE.

[0436] Step 1304: UDM sends a registration response message to AMF 1.

[0437] Optionally, the registration response message also includes first information that the UE performs dual connection, and the first information is used to determine whether the UE can access the network through the current path. Exemplarily, the first information indicates the type of radio access technology RAT that allows the UE to access the network, or the first information indicates a combination of RAT types that allows the UE to access the network through two paths. For example, if the first information is TN, the UE is allowed to access the network through TN. For another example, if the first information is a combination of RAT types on two paths: TN and NTN, or 5G and 6G, etc., the UE is allowed to access the network through a TN path and an NTN path, or the UE is allowed to access the network through a 5G path and a 6G path.

[0438] In a possible implementation, the first information is in the subscription data of the UE, which can be understood as the UDM obtaining the first information from the subscription data of the UE.

[0439] Step 1305 (optional): AMF1 obtains the first information.

[0440] In one possible implementation, the AMF obtains the first information from the UDM. For example, AMF1 sends dual-divergence indication information to the UDM, and the dual-divergence indication information indicates that the UE supports accessing the network through two different paths at the same time. The UDM can determine the first information of the UE based on the dual-divergence indication information, and send the first information to AMF1. For another example, the UDM determines that the UE supports accessing the network through two different paths at the same time based on the UE's subscription data, and sends the first information to AMF1. For example, the first information is the RAT type that allows the UE to access the network, or a combination of RAT types that allow the UE to access the network through two paths, such as the combination of RAT types of TN and NTN, or 5G and 6G, etc. Exemplarily, the AMF sends a subscription data request message to the UDM, and the subscription data request message includes the dual-divergence indication information. The UDM replies with subscription data to the AMF, and the subscription data includes the first information.

[0441] In another possible implementation, the AMF obtains the first information from the PCF. Exemplarily, AMF1 sends dual-divergence indication information to the PCF, and the dual-divergence indication information indicates that the UE supports accessing the network through two different paths at the same time. The PCF can determine the first information of the UE based on the dual-divergence indication information, and send the first information to AMF1. For another example, the PCF obtains the subscription data of the UE from the UDM, determines that the UE supports accessing the network through two different paths at the same time based on the subscription data of the UE, and sends the first information to AMF1. For example, the first information is the RAT type that allows the UE to access the network, or the combination of RAT types that allow the UE to access the network through two paths, such as the combination of RAT types of TN and NTN, or 5G and 6G, etc. Exemplarily, the AMF sends an AM policy request message to the PCF, and the AM policy request message includes the dual-divergence indication information. The PCF replies to the AMF with the AM policy, and the AM policy includes the first information.

[0442] In one possible implementation, the UDM or PCF determines the first information based on the dual-split indication information and the RAT type of the first path. For example, the UDM or PCF determines that the combination of RAT types allowed to be accessed by the UE is 5G and 6G, and the UDM or PCF determines that the RAT type of the first path is 5G, thereby determining that the first information is 6G, that is, the RAT type allowed to access the network through the second path of the UE is 6G.

[0443] It should be noted that if there is no restriction on the RAT type accessed by the UE, the first information is not sent to the AMF, that is, step 805 is not performed.

[0444] Step 1306 (optional): AMF1 determines whether the UE is allowed to access.

[0445] In one possible implementation, AMF1 determines whether the UE meets the requirements of the first information based on the RAT type currently accessed by the UE, thereby determining whether to allow the UE to access. It should be noted that the determination of whether to allow the UE to access here refers to whether to allow access to the network through DualSteer. In other words, if the UE does not meet the requirements of the first information, it can still access the network through a single connection in the existing technology.

[0446] Exemplarily, the first information is that the UE is allowed to access the network through 5G and 6G. If the RAT type on the AMF1 side is 4G, it can be determined that the UE is not allowed to access. Alternatively, if the RAT type on the AMF1 side is 5G, it can be determined that the UE is allowed to access. In one possible implementation, if the AMF1 determines that the UE is not allowed to access, it can reply to the UE with a registration acceptance message and instruct the UE not to use dual connectivity.

[0447] When AMF1 determines that the UE is allowed to access, step 1307a is executed, and AMF 1 sends a registration acceptance message to the UE. Furthermore, the AMF may also send the allowed RAT type combinations to the UE, and the UE can subsequently select the corresponding RAT based on the RAT types allowed by the network. For example, if the current restriction allows the UE to access through a combination of TN and NTN, and the UE's first path is TN, then when the UE selects RAN2, only the NTN RAN is considered, so that the RAT type combination of the two paths meets the network requirements. For example, if the allowed RAT type is NTN, the UE can select a cell with an NTN RAT type based on the RAT type carried in the cell's broadcast message.

[0448] If AMF1 determines that the UE is not allowed to access, step 1307b is executed, and AMF2 sends a registration reject message to the UE. Furthermore, the AMF may send the UE the allowed RAT types, and the UE may subsequently select the corresponding RAT based on the RAT types allowed by the network. In another possible implementation, AMF2 sends a registration accept message to the UE, which includes indication information indicating that the UE is not allowed to use dual connectivity.

[0449] Step 1308: The UE sends an access network (AN) message to RAN2.

[0450] Optionally, the AN message includes dual-flow indication information, and the dual-flow indication information is used to retain the connection of the first path when establishing the connection of the second path.

[0451] Optionally, the UE selects RAN2 on the second path according to the RAT type allowed by the network side obtained in step 807a. For example, if the allowed RAT type is 6G, the UE selects the 6G RAN to perform the registration process.

[0452] In one possible implementation, the registration request message in the AN message includes dual-split indication information. For example, the dual-split indication information is a newly added registration type. The dual-split indication information is a field in the registration type. Exemplarily, the name of the newly added registration type can be DualSteer Registration. The name is not limited here. The registration type is DualSteer Registration, which is used to indicate to the network that the registration is a second path for dual-connection registration for the UE.

[0453] In another possible implementation, the registration request message includes an additional indication information, which indicates to the network that the UE is registering the second path for dual connectivity at this time. At this time, the registration type of the UE may be an initial registration. The AMF determines that the registration type of the UE is an initial registration, and according to the indication information of the UE, it can be determined that the registration is for the UE to perform dual connectivity registration for the second path.

[0454] Through the above implementation method, after the same AMF receives the second registration request message of the same UE, it can determine the UE context of the UE according to the 5G-GUTI of the UE in the registration request message, and retain the information of the N2 connection of the second path in the UE context information. It can be understood that the AMF can retain two N2 connections for the same UE, or it can be understood that the AMF maintains the N2 connection with the UE through two paths at the same time.

[0455] Step 1309: RAN2 selects AMF.

[0456] In one possible implementation, the dual-divergence indication information is in a field that the RAN can parse in the AN parameters, for example, in the AN parameters, or in the AN message in parallel with the AN parameters and the registration request message. RAN2 selects an AMF that supports dual connectivity based on the dual-divergence indication information in the AN message. Since the UE obtains the 5G-GUTI assigned by AMF1 during the first registration, the UE can obtain the identification information of AMF1 based on the 5G-GUTI. The UE can carry the identification information of AMF1 (such as GUAMI or 5G-S-TMSI) in the AN parameters during the second registration. RAN2 determines whether AMF1 supports dual connectivity based on the dual-divergence indication information and the identification information of AMF1. It should be noted that RAN will save the information on whether AMF supports dual connectivity. Exemplarily, RAN determines the capability information of whether AMF1 supports dual connectivity based on the identification information of AMF1, thereby determining whether AMF1 supports dual connectivity.

[0457] RAN2 selects AMF in the following two situations:

[0458] Case 1: If AMF1 supports maintaining two N2 connections for the same UE at the same time and RAN2 can access it, RAN2 selects AMF1 to serve the UE.

[0459] Case 2: If AMF1 does not support maintaining two N2 connections for the same UE at the same time, or RAN2 cannot connect to AMF1, for example, when the UE accesses from NTN, due to the large satellite coverage, RAN2's ground gateway station may be in a different area from AMF1. RAN2 and AMF1 cannot connect directly, so RAN2 will select AMF2, which is different from AMF1, according to its own area.

[0460] For case 1, RAN2 selects AMF1 of the first path, and subsequent steps are shown in 1310a-1314a below.

[0461] Step 1310a: RAN2 sends a registration request message to AMF1.

[0462] The registration request message includes 5G-GUTI and dual-split indication information. 5G-GUTI is used by the AMF to associate the UE context created when the UE registers from the first path. The dual-split indication information is used to indicate to the AMF that the second path is used to implement UE dual connectivity and does not need to replace the UE's first path connection, or to indicate that the UE supports dual connectivity, or to indicate that the UE wishes to access the network through dual connectivity, or to indicate that the first path connection is retained when establishing a second path connection.

[0463] In a possible implementation, RAN2 sends an NGAP message, also referred to as an N2 message, to AMF1, wherein the N2 message includes the registration request message.

[0464] Step 1311a (optional): AMF determines whether to allow UE access.

[0465] In one possible implementation, AMF1 determines whether the UE meets the requirements of the first information based on the RAT type currently accessed by the UE, thereby determining whether to allow the UE to access. It should be noted that the determination of whether the UE is allowed to access here refers to whether it is allowed to access the network through dual connections. In other words, if the UE does not meet the requirements of the first information, it can still access the network through a single connection in the prior art. In a possible implementation, when the first information is the RAT type that allows the UE to access the network, AMF1 determines whether the first information includes the RAT type corresponding to the second path. Exemplarily, the first information is to allow the UE to access the network through 5G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. At this time, AMF1 can determine that the UE is not allowed to access. In another example, the first information is to allow the UE to access the network through 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 6G. At this time, AMF1 can determine that the UE is allowed to access.

[0466] For example, if the first information allows the UE to access the network through 5G and 6G, AMF1 may determine whether the first information includes the RAT type corresponding to the second path. When the RAT type corresponding to the second path is 5G or 6G, AMF1 may determine that the UE is allowed to access the network through the second path. When the RAT type corresponding to the second path is 4G, AMF1 may determine that the UE is not allowed to access the network through the second path.

[0467] In another possible implementation, when the first information is a combination of RAT types that allow the UE to access the network, AMF1 determines whether the first information includes the RAT type corresponding to the UE accessing the network through the second path. For example, if the first information allows the UE to access the network through a combination of 5G and 6G, and the RAT type corresponding to the UE accessing the network through the second path is 4G, AMF1 may determine that the UE is not allowed to access.

[0468] For the relevant description of AMF judgment, please refer to the relevant description in step 1103 in Figure 11 above, which will not be repeated here.

[0469] It should be noted that since the UE has completed the authentication and security process during the first registration and accessed the network through the same AMF (i.e., AMF1), the AMF does not need to perform the authentication and security process for the UE again. The AMF can save the relevant information of the UE's second path in the UE context. Since AMF1 is selected for both registrations, AMF1 can obtain the RAT types of the two paths and determine whether to allow the UE to access by comparing the RAT type combination accessed by the UE with the RAT type combination required by the network side.

[0470] When AMF1 determines that the UE is allowed to access, step 1312a is executed, and AMF1 sends a registration acceptance message to the UE through RAN2.

[0471] If AMF1 determines that the UE is not allowed to access, step 1313a is executed, and AMF1 sends a registration rejection message to the UE through RAN2. Furthermore, AMF1 can also send the allowed RAT types to the UE, and the UE can subsequently select the corresponding RAT based on the RAT types allowed by the network side.

[0472] In one possible implementation, when the AMF determines that the UE is not allowed to access, step 1314a is executed. The AMF may accept the registration request of the UE's second path and release the UE's first path. For example, when the network side requires the UE to access through a combination of TN and NTN, the UE accesses the network from TN on the first path and also accesses the network from TN on the second path. At this time, the UE's RAT type combination is TN and TN, and the network side requires TN and NTN. Obviously, the UE does not meet the requirements of the network side. Therefore, the AMF can reject the registration request initiated by the UE from the second path, or choose to accept the UE's registration request on the second path and replace the connection of the first path.

[0473] For the second scenario, when RAN2 selects AMF2 which is different from AMF1, the subsequent steps are shown in 1310b-1318b below.

[0474] Step 1310b: RAN2 sends a registration request message to AMF2.

[0475] The registration request message includes 5G-GUTI and dual-split indication information. 5G-GUTI is used by AMF2 to indicate the AMF1 that the UE is registered with on the first path. Subsequently, AMF2 can obtain relevant information about the UE context from AMF1. The dual-split indication information is used to indicate to the AMF that the second path is used to implement dual connectivity for the UE. It can also indicate that the UE supports dual connectivity, or that the UE wishes to access the network via dual connectivity, or that the connection on the first path should be retained while establishing a connection on the second path.

[0476] Step 1311b: Obtain UE context information.

[0477] The UE context information includes the RAT type of the UE on the first path.

[0478] In one possible implementation, AMF2 determines the AMF1 registered by the UE on the first path based on the identification information of AMF1 in the 5G-GUTI, and requests UE context information from AMF1, including the first information obtained by AMF1 from the UDM or PCF, that is, the RAT type combination information allowed to be accessed by the UE, and the RAT type of the UE on the first path. It should be noted that when the registration request message sent by the UE to AMF1 in step 1308 includes dual split indication information, AMF2 obtains the dual split indication information from the UE.

[0479] Optionally, the context information sent by AMF1 to AMF2 also includes the dual-split indication information of the UE. When the registration request message sent by the UE to AMF1 in step 1301 includes the dual-split indication information, AMF2 can obtain the dual-split indication information from AMF1.

[0480] In another possible implementation, AMF2 obtains the context information of the UE from the UDM. For example, AMF2 requests the context of the UE from the UDM, and the request message includes the identification information of the UE. AMF2 receives the context of the UE from the UDM, wherein the context of the UE includes the RAT type of the UE on the first path.

[0481] Step 1312b (optional): AMF2 determines whether the UE is allowed to access.

[0482] In one possible implementation, AMF2 determines whether the UE meets the requirements of the first information based on the RAT type currently accessed by the UE, thereby determining whether to allow the UE to access. It should be noted that the determination of whether to allow the UE to access here refers to whether to allow access to the network through dual connectivity. In other words, if the UE does not meet the requirements of the first information, it can still access the network through a single connection in the prior art.

[0483] For related descriptions, please refer to the above-mentioned instructions for step 1103, which will not be repeated here.

[0484] When AMF2 determines that the UE is allowed to access, execute step 1316b.

[0485] If AMF2 determines that the UE is not allowed to access, it executes step 1317b to retain the previous first path or executes step 1318b to retain the newly established second path. Furthermore, the AMF may send the allowed RAT types to the UE, and the UE may subsequently select the corresponding RAT based on the RAT types allowed by the network. For example, if the allowed RAT type is NTN, the UE may select a cell with an NTN RAT type based on the RAT type carried in the cell's broadcast message.

[0486] Step 1313b: AMF2 triggers the authentication and security procedure with the UE, AUSF, and UDM.

[0487] For the related description, please refer to the related description in step 204 of FIG. 2 , which will not be repeated here.

[0488] Step 1314b: AMF2 sends a registration request message to UDM.

[0489] The registration request message includes dual split indication information. The registration request message is used for AMF 2 to register with UDM as the AMF serving the UE.

[0490] After obtaining the dual split indication information, the UDM determines that two different UE contexts can be saved for the UE in the UDM, and therefore saves the second UE context for the UE, that is, the UDM determines that two different UE contexts can be saved for the UE under the same access type.

[0491] It should be noted that if AMF2 determines that the RAT type currently accessed by the UE cannot meet the requirements of the network side, for example, the network side requires the UE to access the network through a combination of RAT types of TN and NTN, and the RAT types currently selected by the UE are TN and TN, then AMF2 believes that it is impossible for the UE to access the network through these two paths at the same time. At this time, the registration request message sent by AMF2 to UDM does not include dual-diversion indication information, that is, UDM will determine that AMF2 is used to replace AMF1 based on the registration request message sent by AMF2, so that UDM sends a de-registration request to AMF1, thereby causing AMF1 to de-register.

[0492] Step 1315b: UDM sends a registration response message to AMF 2.

[0493] Step 1316b: AMF 2 sends a registration accept message to the UE.

[0494] If AMF2 determines that the RAT type currently accessed by the UE meets the requirements of the network side, AMF2 can allow the UE to access through the current RAT type and send a registration acceptance message to the UE.

[0495] Step 1317b: AMF2 sends a registration reject message to the UE.

[0496] Optionally, the registration rejection message includes the allowed RAT type. The UE can subsequently select the RAN corresponding to the RAT type allowed by the network to register with the network.

[0497] In one possible implementation, AMF2 determines the allowed RAT type based on the first information and the RAT type of the first path. For example, the first information allows the UE to access the network through a combination of 5G and 6G, and the RAT type of the first path is 5G. Therefore, the registration rejection message sent to the UE includes that the allowed RAT type is a 6G RAT type.

[0498] Step 1318b: AMF2 receives the second path and releases the first path.

[0499] In one possible implementation, AMF2 sends a registration acceptance message of the second path to the UE through RAN2, and releases the first path for the UE to access the network through RAN1 and AMF1.

[0500] In a possible implementation manner, the registration acceptance message of the second path includes the first information.

[0501] It should be noted that AMF2 determines that UE access is not allowed. One possible scenario is that the first information allows the UE to access the network through a combination of 5G and 6G. The first path is of 5G RAT type, and the second path is also of 5G RAT type. Therefore, one of the paths can be retained. One possible implementation method is to retain the second path and release the first path.

[0502] In a possible implementation, AMF2 may send a request message to UDM to release the first path, and then UDM releases the first path connecting AMF1 and RAN1.

[0503] Through the steps of method 1300, in a dual connectivity scenario, the UE obtains the RAT type allowed for the UE to access the network from the UDM or PCF through the AMF, so that the AMF can determine whether the UE can access the network through the current path based on the RAT type of the current path and the RAT type allowed for the UE to access the network, and sends the RAT type allowed for the UE to the UE, so that the UE can access the network through the RAT type specified by the network. The network notifies the UE of the RAT type allowed for network access, so that the UE selects an appropriate RAT type for access, avoiding the UE from selecting an inaccessible RAT, thereby increasing the success rate of UE access.

[0504] The following describes a method 1400 for a communication device to obtain a RAT type during a registration process, provided in accordance with an embodiment of the present application, in conjunction with FIG14 . It should be noted that FIG14 is used as an example for description herein, and this method is applicable to any of the processes in FIG5 to FIG13 . The communication device may be a terminal device (e.g., UE 110 in FIG1 ), or a chip (system) that may be provided in the terminal device. In other words, method 1400 may be executed by the terminal device, or by a chip (system) in the terminal device.

[0505] The communication method flow diagram shown in FIG14 may include the following steps:

[0506] Step 1401: The communication device sends a registration request message to an access and mobility management network element.

[0507] The registration request message includes second indication information, and the second indication information indicates that the communication device supports dual connectivity.

[0508] There are two situations in which a communication device sends a registration request message to a mobility management network element:

[0509] Case 1: The communication device registers with the network through a first path.

[0510] Case 2: The communication device has accessed the network through the first path, and now the communication device registers with the network through the second path.

[0511] In a possible implementation, the second indication information may be the indication information in method 600 , and the specific implementation of step 1401 may refer to the above steps 602 to 605 .

[0512] In another possible implementation, the second indication information may be information used in method 800 to generate a communication device context for the second path that is different from the first path. For the specific implementation of step 1401 , refer to the above step 802 .

[0513] In another possible implementation, the second indication information may be the indication information in method 1000 , and the specific implementation of step 1401 may refer to the above steps 1000 to 1004 .

[0514] Step 1402: The access and mobility management network element obtains second information.

[0515] The access and mobility management network element obtains second information according to the second indication information, wherein the second information indicates a RAT type that the communication device is allowed to access the network.

[0516] In a possible implementation, the specific implementation of step 1402 can refer to step 1102 in method 1100.

[0517] In another possible implementation, the specific implementation of step 1402 can refer to step 1202 in method 1200.

[0518] In another possible implementation, the specific implementation of step 1402 can refer to step 1305 in method 1300.

[0519] Step 1403: The access and mobility management network element determines whether to allow the communication device to access based on the second information.

[0520] In one possible implementation, the second information includes the RAT type corresponding to the access path of the communication device, and the access and mobility management network element sends a registration acceptance message to the communication device (execute step 1404a). For situation 1, the registration acceptance message may also include the second information.

[0521] In a possible implementation, the second information does not include the RAT type corresponding to the access path of the communication device, and the access and mobility management network element sends a registration rejection message to the communication device (execute step 1404b).

[0522] For situation 2, in one possible implementation, the second information includes a combination of RAT types corresponding to the two paths, and the access and mobility management network element sends a registration acceptance message to the communication device (execute step 1404a).

[0523] For situation 2, in a possible implementation, the second information does not include a combination of RAT types corresponding to the two paths, and the access and mobility management network element sends a registration reject message to the communication device (execute step 1404b).

[0524] For scenario 2, in another possible implementation, the second information does not include the combination of RAT types corresponding to the two paths. The access and mobility management network element sends a registration accept message to the communication device via the second path and releases the connection of the first path. For related descriptions, see step 1104c in method 1100 or step 1204c in method 1200.

[0525] Step 1404a: The access and mobility management network element sends a registration acceptance message to the communication device.

[0526] In a possible implementation, the registration acceptance message includes the second information. For a specific implementation of step 1404a, see step 1104a in method 1100 or step 1204a in method 1200.

[0527] Step 1404b: The access and mobility management network element sends a registration rejection message to the communication device.

[0528] In a possible implementation, the registration rejection message includes the second information. For a specific implementation of step 1404b, see step 1104b in method 1100 or step 1204b in method 1200.

[0529] Step 1405: The communication device selects a radio access network device according to the second information.

[0530] In one possible implementation, the communication device sends an AN message to a radio access network device of the RAT type that is allowed to access the network based on the second information. The AN message is used to request that the communication device be registered with the network. It should be noted that the communication device may perform this step if it cannot access the network through both paths. For example, if the communication device receives a registration acceptance message or a registration rejection message for the first path, or if the communication device receives a registration rejection message for the second path, the communication device may select a radio access network device that meets the second information to access the network.

[0531] The access and mobility management network element obtains the RAT type that the communication device is allowed to access the network, so that the access and mobility management network element can determine whether the communication device can access the network through the current path based on the RAT type of the current path and the RAT type that the communication device is allowed to access the network, and sends the RAT type that the communication device is allowed to access the network to the communication device, so that the communication device can access the network through the RAT type specified by the network. The network notifies the UE of the RAT type that is allowed to access the network, so that the UE selects the appropriate RAT type for access, avoiding the UE from selecting an inaccessible RAT and increasing the UE's access success rate.

[0532] The above description of the communication method embodiment of the present application is described in detail in conjunction with Figures 5 to 14. The following description of the communication device embodiment of the present application is described in detail in conjunction with Figures 15 to 17. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for portions not described in detail, reference can be made to the above method embodiment.

[0533] Figure 15 is a schematic diagram of the structure of a communication device 1000 provided in an embodiment of the present application. As shown in Figure 15, the device 1000 may include a transceiver unit 1010 and a processing unit 1020. The transceiver unit 1010 can communicate with the outside world, and the processing unit 1020 is used to process data. The transceiver unit 1010 may also be referred to as a communication interface or a transceiver unit.

[0534] In one possible design, the device 1000 can implement steps or processes corresponding to those performed by the communication device in the above method embodiment, wherein the processing unit 1020 is used to perform processing-related operations of the communication device in the above method embodiment, and the transceiver unit 1010 is used to perform transceiver-related operations of the communication device in the above method embodiment.

[0535] In another possible design, the device 1000 can implement steps or processes corresponding to those performed by the access and mobility management network element in the above method embodiment, wherein the transceiver unit 1010 is used to perform operations related to the reception and transmission of the access and mobility management network element in the above method embodiment, and the processing unit 1020 is used to perform operations related to the processing of the access and mobility management network element in the above method embodiment.

[0536] In another possible design, the device 1000 can implement steps or processes corresponding to those executed by the wireless access network device in the above method embodiment, wherein the processing unit 1020 is used to perform processing-related operations of the wireless access network device in the above method embodiment, and the transceiver unit 1010 is used to perform transceiver-related operations of the wireless access network device in the above method embodiment.

[0537] It should be understood that the device 1000 here is embodied in the form of a functional unit. The term "unit" here can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a merging logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art can understand that the device 1000 can be specifically the transmitting end in the above embodiment, and can be used to execute the various processes and / or steps corresponding to the transmitting end in the above method embodiment, or the device 2000 can be specifically the receiving end in the above embodiment, and can be used to execute the various processes and / or steps corresponding to the receiving end in the above method embodiment. To avoid repetition, it will not be repeated here.

[0538] The apparatus 1000 of each of the above-mentioned solutions has the function of implementing the corresponding steps performed by the transmitting end in the above-mentioned method, or the apparatus 1000 of each of the above-mentioned solutions has the function of implementing the corresponding steps performed by the receiving end in the above-mentioned method. The functions can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions; for example, the transceiver unit can be replaced by a transceiver (for example, the transmitting unit in the transceiver unit can be replaced by a transmitter, and the receiving unit in the transceiver unit can be replaced by a receiver), and other units, such as the processing unit, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0539] In addition, the above-mentioned transceiver unit can also be a transceiver circuit (for example, it can include a receiving circuit and a transmitting circuit), and the processing unit can be a processing circuit. In an embodiment of the present application, the device 1000 can be the receiving end or the transmitting end in the aforementioned embodiment, or it can be a chip or a chip system, such as a system on chip (SoC). Among them, the transceiver unit can be an input and output circuit or a communication interface. The processing unit is a processor or microprocessor or integrated circuit integrated on the chip. This is not limited here.

[0540] Figure 16 is a schematic diagram of the structure of a communication device 2000 provided in an embodiment of the present application. As shown in Figure 16, the device 2000 includes a processor 2010 and a transceiver 2020. The processor 2010 and the transceiver 2020 communicate with each other via an internal connection path. The processor 2010 is used to execute instructions to control the transceiver 2020 to send and / or receive signals.

[0541] Optionally, the apparatus 2000 may further include a memory 2030, which communicates with the processor 2010 and the transceiver 2020 via an internal connection path. The memory 2030 is used to store instructions, and the processor 2010 may execute the instructions stored in the memory 2030.

[0542] In a possible implementation, the device 2000 is used to implement various processes and steps corresponding to the communication device in the above method embodiment.

[0543] In another possible implementation, the apparatus 2000 is used to implement various processes and steps corresponding to the access and mobility management network elements in the above method embodiment.

[0544] In another possible implementation, the apparatus 2000 is used to implement various processes and steps corresponding to the wireless access network device in the above method embodiment.

[0545] It should be understood that the device 2000 can be specifically the transmitting end or receiving end in the above-mentioned embodiments, or can also be a chip or chip system. Correspondingly, the transceiver 2020 can be the transceiver circuit of the chip, which is not limited here. Specifically, the device 2000 can be used to perform the various steps and / or processes corresponding to the transmitting end or receiving end in the above-mentioned method embodiments.

[0546] Optionally, the memory 2030 may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information. The processor 2010 may be configured to execute instructions stored in the memory. When the processor 2010 executes the instructions stored in the memory, the processor 2010 is configured to perform the various steps and / or processes of the above-described method embodiments corresponding to the transmitting end or the receiving end.

[0547] During implementation, each step of the above method can be completed by an integrated logic circuit of the hardware in the processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0548] It should be noted that the processor in the embodiments of the present application can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above-mentioned method embodiment can be completed by hardware integrated logic circuits in the processor or by software instructions. The above-mentioned processor can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The processor in the embodiments of the present application can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above-mentioned method.

[0549] It will be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory, dynamic random access memory, synchronous dynamic random access memory, double data rate synchronous dynamic random access memory, enhanced synchronous dynamic random access memory, synchronous linked dynamic random access memory, and direct memory bus random access memory. It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0550] FIG17 is a schematic diagram of the structure of a chip system 3000 provided in an embodiment of the present application. As shown in FIG17 , the chip system 3000 (or also referred to as a processing system) includes a logic circuit 3010 and an input / output interface 3020 .

[0551] The logic circuit 3010 may be a processing circuit in the chip system 3000. The logic circuit 3010 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 3000 can implement the methods and functions of the various embodiments of the present application. The input / output interface 3020 may be an input / output circuit in the chip system 3000, outputting information processed by the chip system 3000 or inputting data or signaling information to be processed into the chip system 3000 for processing.

[0552] As a solution, the chip system 3000 is used to implement the operations performed by the communication device in the above various method embodiments.

[0553] As a solution, the chip system 3000 is used to implement the operations performed by the access and mobility management network element in the above various method embodiments.

[0554] As a solution, the chip system 3000 is used to implement the operations performed by the wireless access network device in the above various method embodiments.

[0555] An embodiment of the present application also provides a computer-readable storage medium on which computer instructions are stored for implementing the methods executed by the communication device, access and mobility management network element, and wireless access network equipment in the above-mentioned method embodiments.

[0556] An embodiment of the present application also provides a computer program product, comprising computer program code or instructions. When the computer program code or instructions are executed on a computer, the computer implements the methods performed by the communication device, access and mobility management network element, and wireless access network equipment in the above-mentioned method embodiments.

[0557] An embodiment of the present application also provides a communication system, including the aforementioned communication device, access and mobility management network element and wireless access network equipment, and optionally, may also include UDM or PCF.

[0558] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0559] To facilitate understanding of the above embodiments provided in this application, the following points are explained:

[0560] 1) In this application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0561] 2) In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Where a, b and c can be single or multiple, respectively.

[0562] 3) Throughout this application, the terms "first," "second," and various numerical references (e.g., #1, #2, etc.) are used to distinguish between different messages for ease of description and are not intended to limit the scope of the embodiments of this application. For example, they are used to distinguish between different messages, rather than to describe a specific order or precedence. It should be understood that such references are interchangeable, where appropriate, to allow for the description of scenarios beyond the embodiments of this application.

[0563] 4) In this application, descriptions such as "when...", "in the case of...", and "if" all mean that the device will perform corresponding processing under certain objective circumstances. They do not limit the time, nor do they require the device to perform judgment actions when implementing them, nor do they mean that there are other limitations.

[0564] 5) In this application, "used to indicate" can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, and it does not mean that the indication information must carry A.

[0565] The indication methods involved in the embodiments of this application should be understood to encompass various methods that enable the party to be indicated to obtain information to be indicated. The information to be indicated can be sent as a whole or divided into multiple sub-information and sent separately. The transmission period and / or timing of these sub-information can be the same or different. This application does not limit the specific transmission method.

[0566] In the embodiments of the present application, the "indication information" may be an explicit indication, i.e., a direct indication via signaling, or may be obtained based on parameters indicated by the signaling, in combination with other rules, other parameters, or by deduction. It may also be an implicit indication, i.e., based on a rule or relationship, or based on other parameters, or by deduction. This application does not impose specific limitations on this.

[0567] 6) In this application, "protocol" may refer to a standard protocol in the field of communications, such as 5G protocol, NR protocol, and related protocols used in future communication systems, which are not limited in this application. "Predefined" may include pre-definition. For example, protocol definition. "Preconfiguration" can be implemented by pre-saving corresponding codes, tables, or other methods that can be used to indicate relevant information in the device. This application does not limit its specific implementation method.

[0568] 7) In this application, "communication" may also be described as "data transmission", "information transmission", "data processing", etc. "Transmission" includes "sending" and "receiving".

[0569] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0570] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0571] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0572] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0573] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0574] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk, or an optical disk.

[0575] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: The method comprises: The communication device accesses the network through a first path connecting the first radio access network device and the first access and mobility management network element; The communication device sends a request message to a second wireless access network device, where the request message is used to request that the communication device be registered to the network. The request message includes indication information, where the indication information is used by the second wireless access network device to select a second access and mobility management network element that is different from the first access and mobility management network element. The communication device simultaneously accesses the network through the first path and a second path connecting the second wireless access network device and the second access and mobility management network element.

2. The method according to claim 1, characterized in that: The indication information indicates that the communication device supports accessing the network through two different paths at the same time, or indicates that the communication device hopes to access the network through two different paths at the same time, and the two different paths respectively connect two different wireless access network devices and two different access and mobility management network elements; or, the indication information indicates the selection of different access and mobility management network elements.

3. The method according to claim 1 or 2, characterized in that: The request message includes access network parameters, wherein the access network parameters include the indication information.

4. The method according to any one of claims 1 to 3, characterized in that: The request message also includes identification information of the first access and mobility management network element.

5. The method according to any one of claims 1 to 4, characterized in that: Before the communication device sends a request message to the second radio access network device, the method further includes: The communication device determines that it wants to access the network through two different paths at the same time, and the two different paths are respectively connected to two different radio access network devices and two different access and mobility management network elements.

6. A communication method, characterized in that: The method comprises: The communication device accesses the network through a first path connecting the first radio access network device and the first access and mobility management network element; The communication device sends a request message to a second access and mobility management network element through a second radio access network device, where the request message is used to request that the communication device be registered to the network, and the request message includes information used by the second access and mobility management network element to generate a context for the communication device that is different from the first path, the second access and mobility management network element is the same as or different from the first access and mobility management network element, and the communication device simultaneously accesses the network through the first path and a second path connecting the second radio access network device and the second access and mobility management network element.

7. The method according to claim 6, characterized in that The information used for the second access and mobility management network element to generate the context of the communication device that is different from the first path indicates that the communication device supports accessing the network through two different paths at the same time, or indicates that the communication device hopes to access the network through two different paths at the same time, and the two different paths respectively connect two different wireless access network devices and two identical or different access and mobility management network elements; or, the information used for the second access and mobility management network element to generate the context of the communication device that is different from the first path indicates the creation of the context of the communication device.

8. A communication method, characterized in that: The method comprises: The communication device accesses the network through a first path connecting the first radio access network device and the first access and mobility management network element; The communication device sends a request message to a second access and mobility management network element through a second radio access network device, where the request message is used to request that the communication device be registered to the network, and the request message includes indication information, where the indication information is used to retain the connection of the first path when establishing a connection of the second path, the second access and mobility management network element is the same as or different from the first access and mobility management network element, and the communication device simultaneously accesses the network through the first path and a second path connecting the second radio access network device and the second access and mobility management network element.

9. The method according to claim 8, characterized in that The indication information indicates that the communication device supports accessing the network through two different paths at the same time, or indicates that the communication device hopes to access the network through two different paths at the same time, and the two different paths respectively connect two different wireless access network devices and two identical or different access and mobility management network elements; or, the indication information indicates that the connection of the first path is retained when the connection of the second path is established.

10. The method according to claim 8 or 9, characterized in that: The request message includes a registration type, wherein the indication information is a field in the registration type, and the field in the registration type is a dual-connection registration.

11. The method according to any one of claims 8 to 10, characterized in that: Before the communication device sends a request message to the second radio access network device, the method further includes: The communication device determines that it wants to access the network through two different paths at the same time, and the two different paths are respectively connected to two different radio access network devices and two identical or different access and mobility management network elements.

12. The method according to any one of claims 1 to 11, characterized in that: The access type corresponding to the first path and the second path is a third generation partnership project 3GPP access type.

13. The method according to any one of claims 1 to 12, characterized in that: The method further comprises: The communication device receives first information, where the first information is used to indicate a type of radio access technology RAT that allows the communication device to access the network; The communication device selects, based on the first information, a radio access network device corresponding to a RAT type that is allowed to access the network and registers with the network.

14. The method according to claim 13, characterized in that The RAT type corresponding to the second radio access network device is included in the RAT types allowed to access the network.

15. The method according to claim 13 or 14, characterized in that The communication device receives first information, including: The communication device receives the first information from the first access and mobility management network element or the second access and mobility management network element.

16. A communication method, characterized in that: The method comprises: The access and mobility management network element establishes a connection with the communication device via a first path with the first radio access network device; The access and mobility management network element receives a request message from the communication device through a second path with a second radio access network device, the request message being used to request that the communication device be registered with a network, the request message including indication information; The access and mobility management network element reserves the connection of the first path when registering with the network through the second path according to the indication information.

17. The method according to claim 16, characterized in that The indication information indicates that the communication device supports accessing the network through two different paths at the same time, or indicates that the communication device hopes to access the network through two different paths at the same time, and the two different paths respectively connect two different wireless access network devices and two identical or different access and mobility management network elements; or, the indication information indicates that the connection of the first path is retained when the connection of the second path is established.

18. The method according to claim 16 or 17, characterized in that The access and mobility management network element retains the connection of the first path when registering with the network through the second path according to the indication information, including: The access and mobility management network element determines, based on the indication information, that the communication device supports accessing the network through two different paths at the same time, or determines that the communication device wishes to access the network through two different paths at the same time, thereby retaining the connection of the first path while registering to the network through the second path.

19. The method according to any one of claims 16 to 18, characterized in that: The method further comprises: The access and mobility management network element obtains first information, where the first information indicates a radio access technology RAT type that allows the communication device to access a network.

20. The method according to claim 19, characterized in that The access and mobility management network element obtains first information, including: The access and mobility management network element receives first information from a unified data management network element or a policy control network element.

21. A communication method, characterized in that: The method comprises: The wireless access network device receives a request message from the communication device, the request message being used to request that the communication device be registered with the network, the request message including indication information; The wireless access network device obtains identification information of the first access and mobility management network element; The radio access network device selects a second access and mobility management network element different from the first access and mobility management network element according to the identification information of the first access and mobility management network element and the indication information.

22. The method according to claim 21, characterized in that The request message includes access network parameters, wherein the access network parameters include the indication information.

23. The method according to claim 22, characterized in that The identification information of the first access and mobility management network element is obtained from the request message.

24. A communication method, characterized in that: The method comprises: The wireless access network device receives a request message from a communication device, the request message being used to request that the communication device be registered with a network, the request message comprising indication information, the indication information indicating that the communication device supports accessing the network through two different paths at the same time, or indicating that the communication device wishes to access the network through two different paths at the same time; The wireless access network device selects an access and mobility management network element supporting dual connectivity according to the indication information, wherein the access and mobility management network element supporting dual connectivity supports maintaining a connection with the communication device through two different paths at the same time.

25. The method according to claim 24, characterized in that The request message includes access network parameters, wherein the access network parameters include the indication information.

26. The method according to claim 24 or 25, characterized in that The request message also includes identification information of the first access and mobility management network element, and the method further includes: The radio access network device determines, according to the identification information of the first access and mobility management network element, whether the first access and mobility management network element supports dual connectivity; The wireless access network device selects an access and mobility management network element supporting dual connectivity according to the indication information, including: In a case where the first access and mobility management network element supports dual connectivity, the radio access network device selects the first access and mobility management network element to access the network.

27. A communication device, characterized in that: The communication device comprises a module for executing the communication method according to any one of claims 1-15.

28. An access and mobility management network element, characterized in that: The access and mobility management network element comprises a module for executing the communication method according to any one of claims 16-20.

29. A wireless access network device, characterized in that: The radio access network device comprises a module for executing the communication method according to any one of claims 21-26.

30. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a computer program or an instruction. When the computer program or the instruction is executed on a computer, the computer is caused to execute the communication method according to any one of claims 1 to 26.

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