Communication method, network element, terminal device and system

Abstract

A communication method, a network element, a terminal device and a system. The communication method comprises: a first network element receives first indication information from a second network element, the first indication information is used to indicate that current conditions support establishing a session of a first network for the terminal device; after receiving the first indication information, the first network element obtains first quality of service QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through a second network; the first network element sends the first QoS control information to the second network element. The communication method can improve communication efficiency.

Description

Technical Field

[0001] The present application relates to the field of communications, and more specifically, to a communication method, a network element, a terminal device and a system. Background Art

[0002] In the network construction of the fifth generation (5G) communication system in the future, there will be a network architecture in which multiple network systems are interconnected. For example, the interoperable network architecture may include a 5G system and an evolved packet system (EPS), and there is a communication interface between the 5G system and the EPS system to perform interoperability between the communication systems. When a terminal accesses the network, the network can establish contexts in multiple communication systems for the terminal at the same time, for example, establishing a context in both a 5G system and an EPS system. However, in actual communication, the context established in a certain communication system may not be used, so establishing contexts for multiple communication systems will reduce the utilization of communication resources and increase system overhead. Summary of the invention

[0003] The present application provides a communication method, network element, terminal device and system, which can improve communication efficiency.

[0004] In a first aspect, a communication method is provided, including: a first network element receives first indication information from a second network element, the first indication information being used to indicate that current conditions support establishing a session of a first network for a terminal device; after receiving the first indication information, the first network element obtains first quality of service QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through a second network; and the first network element sends the first QoS control information to the second network element.

[0005] In an embodiment of the present application, based on the intercommunication architecture of the first network and the second network, when the conditions indicated by the first indication information are met, a session of the first network of the first session can be established while establishing a session of the second network of the first session. Thus, it is possible to determine the session of the first network of the first session to be established based on current conditions, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency.

[0006] In a possible implementation manner, the first indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0007] In an embodiment of the present application, the first network element determines to obtain the first quality of service QoS control information of the first session of the terminal device of the first network based on the first information included in the first indication information, thereby determining to establish a session of the first network based on the first indication information, avoiding the establishment of unnecessary first network sessions and improving communication efficiency.

[0008] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0009] In the embodiment of the present application, the default bearer identifier of the first network of the terminal device is carried in the first information to implicitly indicate the content of the first information, thereby saving overhead.

[0010] In a possible implementation manner, the first indication information further includes second information, where the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0011] In an embodiment of the present application, the first indication information includes first information and second information. When the condition indicated by the first indication information is met, a session of the first network of the first session can be established while establishing a second network session of the first session, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency.

[0012] In a possible implementation, the method also includes: the first network element obtains third information, and the third information is used to indicate that the attribute of the first session is to ensure continuity; after receiving the first indication information, the first network element obtains first QoS control information of the terminal device, including: after obtaining the first indication information and the third information, the first network element obtains the first QoS control information.

[0013] In an embodiment of the present application, when the network requirements indicated by the first indication information and the conditions indicated by the third information are met, a session of the first network of the first session can be established while establishing a second network session of the first session, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency.

[0014] In a possible implementation, the first network element obtains the first QoS control information of the terminal device, including: the first network element sends a subscription data acquisition request message for the first session to a third network element, the subscription data acquisition request message includes fourth information, and the fourth information is used to request the provision of the subscription data of the first network; the first network element receives a subscription data response message for the first session from the third network element, the subscription data response message includes second QoS control information, wherein the second QoS control information is the subscription data of the first network provided by the fourth information request;.

[0015] In a possible implementation, the first network element obtains the first QoS control information based on the second QoS control information, including: the first network element determines the second QoS control information as the first QoS control information; or, the first network element sends the second QoS control information to a policy control network element; the first network element receives the first QoS control information from the policy control network element, wherein the first QoS control information is based on the second QoS control information, and the first QoS control information is information authorized by the policy control network element.

[0016] In a possible implementation manner, the fourth information includes an access point name APN of the first network.

[0017] In a possible implementation manner, the first network element obtains first QoS control information of the terminal device, including: the first network element receives the first QoS control information from the policy control network element, wherein the first QoS control information is authorized.

[0018] In a possible implementation, the method also includes: the first network element sends a request message for establishing the first session to a policy control network element, the request message for establishing the first session includes fifth information, and the fifth information is used to instruct the policy control network element to establish a session of the first network; the first network element receives the first QoS control information from the policy control network element, including: the first network element receives a response message for establishing the first session from the policy control network element, the response message for establishing the first session includes the first QoS control information.

[0019] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0020] In a possible implementation, the first network element receives the first indication information from the second network element, including: the first network element receives a management request message of the first session from the second network element, and the management request message of the first session includes the first indication information.

[0021] In a possible implementation manner, the first QoS control information is carried in a first session management message, and the first session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0022] According to a second aspect, a communication method is provided, comprising: a second network element sends first indication information to a first network element, wherein the first indication information is used to indicate that current conditions support establishing a session of a first network for a terminal device; and the second network element receives first quality of service QoS control information of a first session of the terminal device from the first network element, wherein the first session is a session established by the terminal device through the second network.

[0023] In an embodiment of the present application, based on the intercommunication architecture of the first network and the second network, when the conditions indicated by the first indication information are met, a session of the first network of the first session can be established while establishing a session of the second network of the first session. Thus, it is possible to determine the session of the first network of the first session to be established based on current conditions, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency.

[0024] In a possible implementation, the method further includes: the second network element receives second indication information from the terminal device, the second indication information being used to indicate that current conditions support establishing a session of the first network for the terminal device; and the second network element determines the first indication information based on the second indication information.

[0025] In a possible implementation manner, the first indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0026] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0027] In a possible implementation manner, the first indication information further includes second information, where the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0028] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0029] In a possible implementation manner, the second network element sends the first indication information to the first network element, including: the second network element sends a management request message of the first session to the first network element, and the management request message of the first session includes the first indication information.

[0030] In a possible implementation manner, the first QoS control information is carried in a first session management message, and the first session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0031] According to a third aspect, a communication method is provided, comprising: a terminal device sends second indication information to a second network element, the second indication information being used to indicate that current conditions support establishing a session of a first network for the terminal device; the terminal device receives first quality of service QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through the second network.

[0032] In an embodiment of the present application, the terminal device sends second indication information to the second network element to indicate that current conditions support establishing a session of the first network for the terminal device, so that the second network element determines the first indication information based on the second indication information, thereby enabling the network side to determine the session of the first network to establish the first session based on the current conditions, avoiding establishing unnecessary sessions of the first network and improving communication efficiency.

[0033] In a possible implementation manner, the second indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0034] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0035] In a possible implementation manner, the second indication information further includes second information, and the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0036] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0037] In a possible implementation manner, the first QoS control information is carried in a second session management message, and the second session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0038] In a fourth aspect, a network element is provided, comprising: a receiving unit, used to receive first indication information from a second network element, the first indication information being used to indicate that current conditions support establishing a session of a first network for a terminal device; an acquiring unit, used to acquire first quality of service QoS control information of a first session of the terminal device after receiving the first indication information, wherein the first session is a session established by the terminal device through the second network; and a sending unit, used to send the first QoS control information to the second network element.

[0039] In a possible implementation manner, the first indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0040] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0041] In a possible implementation manner, the first indication information further includes second information, where the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0042] In a possible implementation, the acquisition unit is also used to acquire third information, and the third information is used to indicate that the attribute of the first session is to ensure continuity; in terms of acquiring the first QoS control information of the terminal device after receiving the first indication information, the acquisition unit is specifically used to acquire the first QoS control information after acquiring the first indication information and the third information.

[0043] In a possible implementation, in terms of obtaining the first QoS control information of the terminal device, the acquisition unit is specifically used to send a subscription data acquisition request message for the first session to a third network element, the subscription data acquisition request message includes fourth information, and the fourth information is used to request the provision of subscription data of the first network; and receive a subscription data response message for the first session from the third network element, the subscription data response message includes second QoS control information for the first network, wherein the subscription data of the first network provided by the fourth information request.

[0044] In a possible implementation, in the aspect of acquiring the first QoS control information according to the second QoS control information, the acquiring unit is specifically configured to determine the second QoS control information as the first QoS control information; or, send the second QoS control information to a policy control network element; and receive the first QoS control information from the policy control network element, wherein the first QoS control information is based on the second QoS control information, and the first QoS control information is information authorized by the policy control network element. .

[0045] In a possible implementation manner, the fourth information includes an access point name APN of the first network.

[0046] In a possible implementation, in terms of acquiring the first QoS control information of the terminal device, the acquisition unit is specifically used to receive the first QoS control information from the policy control network element, wherein the first QoS control information is information authorized by the policy control network element.

[0047] In a possible implementation, the sending unit is also used to send a request message for establishing the first session to a policy control network element, the request message for establishing the first session includes fifth information, and the fifth information is used to instruct the policy control network element to establish a session of the first network; in terms of receiving the first QoS control information from the policy control network element, the acquisition unit is specifically used to receive a response message for establishing the first session from the policy control network element, the response message for establishing the first session includes the first QoS control information.

[0048] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0049] In a possible implementation, in terms of receiving the first indication information from the second network element, the receiving unit is specifically used to receive a management request message of the first session from the second network element, and the management request message of the first session includes the first indication information.

[0050] In a possible implementation manner, the first QoS control information is carried in a first session management message, and the first session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0051] In a fifth aspect, a network element is provided, comprising: a sending unit, used to send first indication information to a first network element, the first indication information being used to indicate that current conditions support establishing a session of a first network for a terminal device; a receiving unit, used to receive first quality of service QoS control information of a first session of the terminal device from the first network element, wherein the first session is a session established by the terminal device through a second network.

[0052] In a possible implementation, the receiving unit is also used to receive second indication information from the terminal device, and the second indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device; the network element also includes a determination unit, and the determination unit is used to determine the first indication information based on the second indication information.

[0053] In a possible implementation manner, the first indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0054] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0055] In a possible implementation manner, the first indication information further includes second information, where the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0056] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0057] In a possible implementation manner, in terms of sending the first indication information to the first network element, the sending unit is specifically used to send a management request message of the first session to the first network element, and the management request message of the first session includes the first indication information.

[0058] In a possible implementation manner, the first QoS control information is carried in a first session management message, and the first session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0059] In the sixth aspect, a terminal device is provided, comprising: a sending unit, used to send second indication information to a second network element, the second indication information being used to indicate that current conditions support establishing a session of the first network for the terminal device; a receiving unit, used to receive first quality of service QoS control information of the first session of the terminal device, wherein the first session is a session established by the terminal device through the second network.

[0060] In a possible implementation manner, the second indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

[0061] In a possible implementation manner, the first information includes a default bearer identifier of the first network of the terminal device.

[0062] In a possible implementation manner, the second indication information further includes second information, and the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0063] In a possible implementation manner, the first QoS control information includes at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0064] In a possible implementation manner, the first QoS control information is carried in a second session management message, and the second session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0065] In a seventh aspect, a communication system is provided, which includes the network elements described in the fourth and fifth aspects above. Optionally, the communication system may also include the terminal device described in the sixth aspect above.

[0066] In an eighth aspect, a network element is provided, the network element comprising: a communication interface, a memory, a processor, and a bus system. The communication interface, the memory, and the processor are connected via the bus system, the memory is used to store instructions, the processor is used to execute the instructions stored in the memory to control the communication interface to receive signals and / or send signals, and when the processor executes the instructions stored in the memory, the execution causes the processor to execute the method in the first aspect or any possible implementation of the first aspect.

[0067] In a ninth aspect, a network element is provided, the network element comprising: a communication interface, a memory, a processor and a bus system. The communication interface, the memory and the processor are connected via the bus system, the memory is used to store instructions, the processor is used to execute the instructions stored in the memory to control the communication interface to receive signals and / or send signals, and when the processor executes the instructions stored in the memory, the execution causes the processor to execute the method in the second aspect or any possible implementation of the second aspect.

[0068] In a tenth aspect, a terminal device is provided, the terminal device comprising: a communication interface, a memory, a processor and a bus system. The communication interface, the memory and the processor are connected via the bus system, the memory is used to store instructions, the processor is used to execute the instructions stored in the memory to control the communication interface to receive signals and / or send signals, and when the processor executes the instructions stored in the memory, the execution causes the processor to execute the method in the third aspect or any possible implementation of the third aspect.

[0069] In the eleventh aspect, a communication system is provided, which includes the network elements described in the eighth and ninth aspects above. Optionally, the communication system may also include the terminal device described in the tenth aspect above.

[0070] In a twelfth aspect, a computer-readable medium is provided for storing a computer program, wherein the computer program includes instructions for executing the method in the first aspect or any possible implementation of the first aspect.

[0071] In a thirteenth aspect, a computer-readable medium is provided for storing a computer program, wherein the computer program includes instructions for executing the method in the second aspect or any possible implementation of the second aspect.

[0072] In a fourteenth aspect, a computer-readable medium is provided for storing a computer program, wherein the computer program includes instructions for executing the method in the third aspect or any possible implementation of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a schematic diagram of a possible application environment of an embodiment of the present application.

[0074] Figure 2 It is a schematic diagram of a possible application environment of yet another embodiment of the present application.

[0075] Figure 3 It is a schematic diagram of a possible application environment of yet another embodiment of the present application.

[0076] Figure 4 It is a flow chart of the communication method of an embodiment of the present application.

[0077] Figure 5 It is an interactive schematic diagram of a communication method according to another embodiment of the present application.

[0078] Figure 6 It is an interactive schematic diagram of a communication method according to another embodiment of the present application.

[0079] Figure 7 It is an interactive schematic diagram of a communication method according to another embodiment of the present application.

[0080] Figure 8 It is an interactive schematic diagram of a communication method according to another embodiment of the present application.

[0081] Fig. 9 It is a schematic diagram of the structure of the network element of the embodiment of the present application.

[0082] Fig.10 It is a structural diagram of a network element of another embodiment of the present application.

[0083] Fig.11 It is a schematic diagram of the structure of a terminal device according to an embodiment of the present application.

[0084] Fig.12 It is a structural diagram of a network element of another embodiment of the present application.

[0085] Fig.13 It is a structural diagram of a network element of another embodiment of the present application.

[0086] Fig.14 It is a schematic diagram of the structure of a terminal device according to another embodiment of the present application. DETAILED DESCRIPTION

[0087] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0088] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, Evolved Packet System (EPS), future fifth generation (5G) system or new radio (NR), etc.

[0089] The terminal device in the embodiments of the present application may refer to a user equipment, an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device. The terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN), etc., and the embodiments of the present application are not limited to this.

[0090] The base station in the embodiment of the present application can be a device for communicating with a terminal device. The base station can be a base station (Base Transceiver Station, BTS) in a Global System of Mobile communication (GSM) system or a Code Division Multiple Access (CDMA), or a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, or an evolved base station (Evolutional NodeB, eNB or eNodeB) in an LTE system, or a wireless controller in a Cloud Radio Access Network (CRAN) scenario, etc., and the embodiments of the present application are not limited.

[0091] The network element in the embodiment of the present application may include a network device in a 5G system architecture and / or a 4G system architecture. The 4G system architecture may include an EPS system architecture. For example, the network element may include an access and mobility management function (AMF) entity, a mobility management entity (MME), a session management function (SMF) entity, a unified data management (UDM), a policy control function (PCF) entity, a policy and charging rule function (PCRF) entity, a packet data network (PDN), a packet data unit (PDU), a control plane gateway (PDN Gateway-Control plane, PGW-C), a user plane gateway (PDN Gateway-User plane, PGW-U), a home subscriber server (HSS), an application function entity (AF), etc.

[0092] To facilitate understanding, relevant terms involved in the embodiments of the present application are first introduced.

[0093] Quality of service (QoS) flow: The smallest QoS forwarding processing granularity in the 5G system. All services mapped to the same QoS flow receive the same forwarding processing, such as packet loss rate, packet delay budget, etc. Different QoS forwarding processing requires different 5G QoS flows.

[0094] Combined with the following Figure 1-Figure 3 , introduces the application environment of the embodiments of the present application. Figure 1-3 They are schematic diagrams of possible system architectures 100-300 of the embodiments of the present application. Figure 1 An interworking architecture 100 between a 5G system and an EPS system in a non-roaming scenario is shown. Figure 2 The intercommunication architecture 200 between the 5G system and the EPS system in a local breakout roaming scenario is shown. Figure 3 The intercommunication architecture 300 of the 5G system and the EPS system in a home-routed roaming scenario is shown.

[0095] In architecture 100-300, in order to support the intercommunication between the 5G system and the EPS system, a first interface is introduced. The above-mentioned first interface refers to the communication interface between the mobility management entity of the 5G system and the mobility management entity of the EPS system. Among them, the mobility management entity of the 5G system may be AMF, and the mobility management entity of the EPS system may be MME. In an embodiment of the present application, the above-mentioned first interface may be represented by the N26 interface. When the system architecture supports the N26 interface, the intercommunication architecture can support switching between the 5G and EPS systems. It should be noted that in the intercommunication architecture, support for the N26 interface is optional, and the switching process can only be used in the intercommunication network that supports the N26 interface to ensure business continuity.

[0096] Specifically, the architecture 100-300 may include network elements in the EPS system and network elements in the 5G system. Some modules in the architecture 100-300 include functions of network elements in the EPS system and network elements in the 5G system. For example, the HSS+UDM module, the PCF+PDRF module, the SMF+PGW-C module, and the UPF+PGW-U module. The modules and communication interfaces involved in the architecture 100-300 are introduced below.

[0097] UPF+PGW-U module: used for transmission management of user data. In the intercommunication architecture, this module can be used for EPS data transmission and provide 5G data transmission function.

[0098] SMF+PGW-C module: used for session establishment, deletion, and modification management. In the interoperability architecture, this module can provide both EPS and 5G session management functions.

[0099] PCF+PCRF module: used for policy and charging control entity. In the interoperability architecture, this module can provide both EPS policy and charging control for terminal devices and 5G policy and charging control.

[0100] HSS+UDM module: used to store user subscription data. In the interoperability architecture, this module stores both the EPS subscription information of the terminal device and the 5G subscription information of the terminal device.

[0101] 5G radio access network (RAN): provides wireless air interface access to the core network for terminal devices to obtain corresponding services.

[0102] Application Function: (AF) interacts with the core network to provide business or services, supports access capability exposure functions, interacts with the policy architecture, and provides application information, etc.

[0103] N5 interface: The interface between PCF and AF, used for AF to directly interact with PCF and transmit service-related information.

[0104] Network Exposure Function (NEF): The business (or service) and capabilities provided by the secure open network function, supporting the interaction between AF and the internal network through NEF.

[0105] Pnt interface: The interface between PCF and NEF, used for interaction between NEF and PCF. Third-party AF can interact with PCF through NEF.

[0106] Evolved universal terrestrial radio access network (E-UTRAN): used for radio resource management, establishing, modifying or deleting air interface resources for terminal devices, providing data and signaling transmission for terminal devices, etc.

[0107] AMF module: used for user access and mobility management, mainly including user registration management, reachability management, mobility management, paging management, access authentication and authorization, encryption and integrity protection of non-access layer signaling, etc.

[0108] MME module: used for user mobility management. For example, it mainly includes user attachment management, reachability management, mobility management, paging management, access authentication and authorization, encryption and integrity protection of non-access layer signaling, etc.

[0109] SGW module: Gateway of the user plane, the user plane termination point with E-UTRAN. Serves as the local mobility anchor point for handover between base stations. Manages the routing and transmission of data packets, adds transport layer packet labels, etc.

[0110] S1-MME interface: control plane interface between MME and E-UTRAN.

[0111] S1-U interface: user plane interface between S-GW and E-UTRAN.

[0112] S5-U interface: user plane interface between SGW and PGW-U, used to transmit user plane data of UE.

[0113] S5-C interface: control plane management interface between SGW and PGW-U, used to establish SGW and PGW-U user plane connection for UE.

[0114] S6a interface: The interface between MME and HSS, used to obtain user subscription data and perform authentication and authorization functions for UE.

[0115] S11 interface: The interface between SGW and MME, used to establish the bearer of the user plane.

[0116] N1 interface: the interface between UE and AMF, for signaling management and transmission of user non-access layer.

[0117] N2 interface: The interface between (R)AN and AMF, used for signaling transmission.

[0118] N3 interface: direct interface between UPF and (R)AN, used to transmit user data.

[0119] N4 interface: The interface between SMF and UPF, used to establish the transmission channel of the user plane.

[0120] N7 interface: The interface between SMF and PCF, used for formulation and distribution of policy control and charging information.

[0121] N8 interface: The interface between AMF and UDM, used to obtain user mobility-related subscription information, etc.

[0122] N10 interface: The interface between SMF and UDM, used to obtain user session management-related contract information, etc.

[0123] N11 interface: The interface between SMF and AMF, used for transmission of session management information, etc.

[0124] N15 interface: The interface between AMF and PCF, used to obtain access and mobility related policy information.

[0125] In addition, in architecture 200:

[0126] h-PCF+h-PCRF represents a policy control body that supports interoperability in a home network or a home network, and supports both 4G policy and charging control functions and 5G policy and charging control functions.

[0127] The S9 / N15 interface represents the interface between PCFs in the home network or the home network.

[0128] In architecture 300:

[0129] v-PCF+v-PCRF represents a policy control body that supports interoperability in a roaming network or a visited network, which supports both 4G policy and charging control functions and 5G policy and charging control functions.

[0130] v-SMF indicates SMF in a roaming network.

[0131] v-PCF indicates the PCF in the roaming network.

[0132] in addition, Figure 2 and Figure 3 The HPLMN in the ISP represents a home network, and the VPLMN represents a visited network or a roaming network. For example, the HPLMN represents a home public land mobile network (HPLMN), and the VPLMN represents a visited or roaming PLMN.

[0133] It is understandable that the above description of the functions of each module is merely an example, and each module may also have other functions, which are not limited in the embodiments of the present invention.

[0134] In some embodiments, during the interoperation between the 5G system and the EPS system, when the terminal device is in an idle state, the terminal device can access the EPS system by means of Tracking area update (TAU). When the terminal device is in a connected state, the switching process between the 5G system and the EPS system mainly includes the following two methods: First, during the interoperation between the 5G system and the EPS system, the Mobility Management / Session Management (MM / SM) contexts are mapped to each other. Second, a solution that supports the reconstruction of the MM / SM context during the switching process between EPS and 5G.

[0135] In some embodiments, the process of switching from a 5G system to an EPS system specifically includes: when establishing a 5G QoS flow in a 5G network, establishing EPS QoS parameters and an EPS bearer identifier (identifier, ID) at the same time. The above-mentioned establishment of EPS QoS parameters and EPS bearer identifiers includes: establishing a default EPS bearer of QoS corresponding to the 5G default rule; further, it may also include: establishing a dedicated EPS bearer corresponding to a 5G guaranteed bit rate (Guaranteed Bit Rate, GBR) QoS flow.

[0136] The embodiment of the present application proposes a communication method based on the intercommunication architecture of the 5G system and the EPS system. It can establish an EPS system session while establishing a 5G system session according to network needs, thereby determining whether to establish an EPS session based on current conditions, avoiding the establishment of unnecessary EPS sessions and improving communication efficiency.

[0137] Combine the following Figure 4 , introduces the communication method of an embodiment of the present application. Figure 4 The method 400 can be applied to Figure 1-Figure 3 In any architecture of . Or, Figure 4 The method can also be applied to other similar architectures. Among them, the first network may include an EPS system network or a 4G system network, and the second network may include a 5G system network. The first network element may be an SMF or an entity having an SMF function. For example, it may be the SMF+PGW-C module in the architecture 100-300, and the second network element may be an AMF or an entity having an AMF function. The third network element may be a UDM or an entity having a UDM function, for example, it may be the HSS+UDM module in the architecture 100-300. The policy control network element may be a PCF or an entity having a PCF function, for example, it may be the PCF+PCRF module in the architecture 100-300. Method 400 includes:

[0138] In step 401, the second network element sends first indication information to the first network element, and correspondingly, the first network element receives the first indication information from the second network element, where the first indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device.

[0139] In some examples, the current conditions support establishing a session of the first network for the terminal device, and may include: an N26 interface exists between the 5G system and the EPS system in the current network. In other words, a communication interface exists between the AMF in the 5G system and the MME in the EPS system. In addition, the current conditions support establishing a session of the first network for the terminal device, and may also include: the terminal device is in a single registration state.

[0140] For example, the first indication information may include first information, and the first information may indicate in an explicit or implicit manner that the current conditions support establishing a session of the first network for the terminal device. In an explicit manner, the first information may directly indicate that the mobility management entity of the second network has a communication interface with the mobility management entity of the first network. For example, the first information is used to indicate that the current network supports the N26 interface between the AMF and the MME, or indicates that the 5G network supports intercommunication with the 4G network. In an implicit manner, the first information may be the default bearer identifier of the first network of the terminal device, and the bearer identifier of the first network of the terminal device may be used to implicitly indicate that the current conditions support establishing a session of the first network for the terminal device. The bearer identifier of the above-mentioned first network may be a dedicated bearer identifier of the first network, or it may be a default bearer identifier of the first network. For example, the default bearer identifier of the first network may be the EPS default bearer identifier of the terminal device, and the dedicated bearer identifier of the first network may be the EPS dedicated bearer identifier of the terminal device.

[0141] In an embodiment of the present application, the first network element determines that it is necessary to obtain the first quality of service QoS control information of the first session of the terminal device of the first network based on the first information included in the first indication information, thereby determining to establish a session of the first network based on the first indication information, avoiding the establishment of unnecessary first network sessions and improving communication efficiency.

[0142] In the embodiment of the present application, the default bearer identifier of the first network of the terminal device is carried in the first information to implicitly indicate the content of the first information, thereby saving overhead.

[0143] It is mentioned in the foregoing that the above-mentioned current conditions support establishing a session of the first network for the terminal device, and may also include: the terminal device is in a single registration state. Among them, if the terminal device is in a single registration state, it means that the terminal device can only be registered in one of the first network or the second network at the same time, for example, it can only be registered in the 5G system or can only be registered in the EPS system. If the terminal device is in a dual registration state, it means that the terminal device can be registered in the first network and the second network at the same time, for example, it can be registered in the 5G network and the EPS network at the same time. If the current network supports the N26 interface and the terminal device is in a single registration state, the first network element determines that a session of the first network needs to be established for the terminal device. If the terminal device is in a dual registration state, that is, the terminal device establishes a context with the first network and the second network at the same time, the terminal device can select any one network for service transmission at any time, for example, the terminal device establishes a context in the 5G system and the EPS system at the same time.

[0144] In the above case, the first indication information may further include second information, where the second information is used to indicate that the terminal device is in a single registration state.

[0145] In an embodiment of the present application, the first indication information includes first information and second information. When the condition indicated by the first indication information is met, a session of the first network of the first session can be established while establishing a second network session of the first session, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency.

[0146] In some examples, the first network element receiving the first indication information from the second network element may include: the first network element receiving a management request message of the first session from the second network element, the management request message of the first session including the first indication information.

[0147] The management request message of the first session may include multiple types. For example, the management request message of the first session may include any one of the following: a session establishment request (PDU session establishment request) message of the first session, a modification request message (PDU session modification request) of the first session. Furthermore, the management request message of the first session may be a service request of a service-oriented interface, such as Namf communication, Nsmf_PDU session service. Among them, Namf refers to the service provided by AMF, which includes the communication or session management provided by SMF, i.e., service.

[0148] In step 402, after receiving the first indication information, the first network element obtains first QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through a second network.

[0149] The first QoS control information may be used to control the quality of service of the service transmitted in the first network. In other words, the first QoS control information may be control information related to the quality of service of the service transmitted in the first network. For example, the first QoS control information may include at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0150] Optionally, after acquiring the first indication information, the first network element may determine, based on the first indication information, whether it is necessary to establish a session of the first network for the terminal device. For example, after receiving the first indication information, the first network element may directly determine that it is necessary to establish a session of the first network for the terminal device. Alternatively, after receiving the first indication information, the first network element may combine the first indication information and other information to determine whether it is necessary to establish a session of the first network for the terminal device. For example, the other information may be the third information described below.

[0151] Optionally, the method 400 further includes: the first network element acquiring third information, the third information being used to indicate that an attribute of the first session is to ensure continuity. The third information may be session continuity mode information of the first session or service and session continuity mode (SSC_mode) information of the first session.

[0152] Optionally, the third information may indicate that the attribute of the first session is to ensure continuity or that the attribute of the first session is that continuity does not need to be ensured. In some examples, the first network element itself stores the third information, or the first network element may obtain contract data from the UDM, and the contract data obtained from the UDM may include the third information. For example, the third information may be SSC_mode information. The first network element obtains the SSC_mode information of the first session from the UDM. If the SSC_mode indicates that the session mode is the first mode, it may indicate that the first session ensures continuity. If the SSC_mode indicates that the session mode is the second mode, it may indicate that the first session does not need continuity.

[0153] In some examples, after obtaining the first indication information, the first network element may further determine whether the attribute of the first session is to ensure continuity. If the attribute of the first session is to ensure continuity, the first network element may determine that a session of the first network needs to be established for the terminal device. If the attribute of the first session is that continuity does not need to be ensured, the first network element may determine that a session of the first network does not need to be established for the terminal device.

[0154] In the embodiment of the present application, when the network requirement indicated by the first indication information and the condition indicated by the third information are met, a session of the first network of the first session can be established while establishing a session of the second network of the first session, thereby avoiding the establishment of unnecessary sessions of the first network and improving communication efficiency. When the third information indicates that the attribute of the first session is that continuity does not need to be guaranteed, the first network element does not need to establish a session of the first network for the terminal device, thereby saving communication resources.

[0155] After the first network element determines that a session of the first network needs to be established for the terminal device based on the first indication information, the first network element can obtain the first QoS control information of the terminal device. For example, the first QoS control information is the QoS control information of the service transmitted in the EPS system. The first QoS control information may include at least one of the following: QoS parameters, identifiers of QoS parameters, packet filters, and priority information of packet filters. For example, the QoS parameters in the first QoS control information may be the QoS parameters of the EPS default bearer of the terminal device, or the QoS parameters of the EPS dedicated bearer of the terminal device. The packet filter and the priority information of the packet filter are the traffic flow template (TrafficFlow Template, TFT) corresponding to the EPS bearer, and the traffic flow template includes at least one packet filter.

[0156] The first network element may obtain the first QoS control information of the terminal device in at least two ways.

[0157] In a first manner, the first network element may obtain the second QoS control information from the third network element, and determine the first QoS control information according to the second QoS control information. The first network element may determine the first QoS control information in two ways. In the first way, the first network element may not modify the second QoS control information, and determine the second QoS control information as the first QoS control information. In the second way, the first network element may send the second QoS control information to the policy control network element, and after receiving the second QoS control information, the policy control network element may determine the first QoS control information according to the second QoS control information, and the first QoS control information is the information authorized by the policy control unit. The policy control network element may modify the second QoS control information to obtain the authorized first QoS control information. Alternatively, the policy control network element may not modify the second QoS control information to obtain the authorized first QoS control information. The policy control network element may send the authorized first QoS control information to the first network element.

[0158] In the second way, the first network element can receive the first QoS control information from the policy control network element, wherein the first QoS control information is information authorized by the policy control network element. The policy control network element can obtain the first QoS control information in two ways. In the first way, the policy control network element can generate the first QoS control information. In the second way, the policy control network element can obtain the contracted third QoS control information from the fourth network element, and the policy control network element can determine the first QoS control information based on the third QoS control information. Specifically, the policy control unit can choose to modify or not modify the third QoS control information to obtain the first QoS control information.

[0159] For the first method, in some examples, the first network element sends a subscription data acquisition request message for the first session to a third network element, and the subscription data acquisition request message includes fourth information, and the fourth information is used to request the provision of subscription data of the first network; the first network element receives a subscription data response message for the first session from the third network element, and the subscription data response message includes second QoS control information, wherein the second QoS control information is subscribed; the first network element obtains the first QoS control information based on the second QoS control information.

[0160] In some examples, the fourth information may include a data network name (DNN) and indicate that the subscription data of the first network needs to be obtained. In other examples, the fourth information may also include an access point name (APN) of the first network to indicate that the subscription data of the first network needs to be obtained.

[0161] Further, the first network element obtains the first QoS control information according to the second QoS control information, which may include: the first network element determines the second QoS control information as the first QoS control information; or the first network element sends the second QoS control information to a policy control network element; the first network element receives the first QoS control information from the policy control network element, wherein the first QoS control information is based on the second QoS control information, and the first QoS control information is information authorized by the policy control network element. .

[0162] For the second method, in some examples, method 400 also includes: the first network element sends a request message for establishing the first session to a policy control network element, the request message for establishing the first session includes fifth information, and the fifth information is used to instruct the policy control network element to establish a session of the first network; the first network element receives the first QoS control information from the policy control network element, including: the first network element receives a response message for establishing the first session from the policy control network element, and the response message for establishing the first session includes the first QoS control information.

[0163] In step 403, the first network element sends the first QoS control information to the second network element, and correspondingly, the second network element receives the first QoS control information from the first network element.

[0164] In some examples, the first QoS control information may be carried in a first session management message, and the first session management message may be used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0165] For example, the first session management message may include multiple types, for example, the first session management message may include any one of the following: a session establishment message, a session modification message. Alternatively, the first session management message may be a message based on a service-based interface.

[0166] In an embodiment of the present application, based on the intercommunication architecture of the first network and the second network, a communication method is proposed. Under the condition of supporting the condition indicated by the first indication information, both the second network session of the first session and the first network session of the first session can be established, thereby being able to determine the first network session of the first session to be established according to the current conditions, avoiding the establishment of unnecessary first network sessions and improving communication efficiency.

[0167] Optionally, before step 401 , method 400 further includes step 404 .

[0168] In step 404, the terminal device sends second indication information to the second network element, and correspondingly, the second network element receives the second indication information, where the second indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device.

[0169] Before step 401, the second network element may determine the first indication information in at least two ways. For example, in the first way, the second network element may receive the second indication information from the terminal device, and may determine the first indication information according to the second indication information. For example, the second network element determines through the second indication information that the current network condition indicates that a session of the first network is established for the terminal device, and may send the first indication information to the first network element to indicate that the current condition supports the establishment of a session of the first network for the terminal device.

[0170] The second indication information may include the first information, and further, the second indication information may also include the second information. For example, the terminal device may obtain fifth information from the second network element during the registration process of the network, and the fifth information is used to indicate that there is a communication interface between the mobility management entity of the second network and the mobility management entity of the first network. The first information is determined based on the fifth information. In the first approach, the first information may be either explicit or implicit.

[0171] In the second approach, the second network element can generate the first indication information by itself. For example, the second network element can obtain the fifth information by itself, and then determine the first information according to the fifth information, and generate the first indication information. Further, the terminal device can send the second information to the second network element so that the second network element adds the second information to the first indication information. In the second approach, the first information is usually explicit.

[0172] For example, the second network element may be an AMF. Therefore, the second network element is a mobility management entity of the second network, and the second network element may determine that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network. Thus, in the case where a communication interface exists, the second network element may generate the first indication information.

[0173] Optionally, after step 403, after the second network element obtains the first QoS control information, the second network element may send the first QoS control information to the base station, and after receiving the first QoS control information, the base station may send the first QoS control information to the terminal device. In this case, method 400 also includes step 405.

[0174] In step 405, the second network element sends the first QoS control information to the terminal device through the base station, and accordingly, the terminal device receives the first QoS control information of the first session of the terminal device, wherein the first session is a session established by the terminal device through the second network.

[0175] The first QoS control information may be used to control the quality of service of the service transmitted in the first network. In other words, the first QoS control information may be control information related to the quality of service of the service transmitted in the first network. For example, the first QoS control information may include at least one of the following: a QoS parameter, an identifier of a QoS parameter, a packet filter, and priority information of a packet filter.

[0176] Optionally, in step 405, the first QoS control information may be carried in a second session management message, where the second session management message is used to instruct modification or establishment of QoS control information in the first network of the terminal device.

[0177] The second session management message may include multiple types. For example, the second session management message may include at least one of the following: a PDU session establishment accept message, an AN-specific resource steup message, and a session modification message. Furthermore, the above message may be a service acquisition interaction of a service-oriented interface.

[0178] Combined with the following Figures 5 to 8 , introduces a specific example of the communication method of the embodiment of the present application. Among them, Figure 5 and Figure 6 The communication flow of the session establishment process is shown. Figure 7 The communication flow during the session modification process is shown. Figure 8 The communication flow of a terminal device registering to a network is shown. Figure 5 The first indication information in is determined according to the second indication information sent by the terminal device. Figure 6 The first indication information in is generated by AMF. Figure 5-Figure 8 The (R)AN in the term "AN" refers to an access network (AN) entity or a radio access network (RAN) entity. For example, the (R)AN may include a base station.

[0179] See below Figure 5 , Figure 5 The method can be applied to architectures 100-300. Figure 5 The process of determining the first indication information according to the second indication information is shown. Figure 5 The methods include:

[0180] S501. A terminal device obtains fifth information during registration with a network, where the fifth information is used to indicate that a communication interface exists between a mobility management entity of a second network and a mobility management entity of a first network.

[0181] For example, the fifth information may indicate that AMF supports the N26 interface (ie, messages can be exchanged between AMF and MME) or that AMF supports intercommunication with 4G.

[0182] S502. The terminal device sends a first PDU session establishment request to the AMF, where the first PDU session establishment request is used to request to establish a first session of the terminal device in the 5G system. The first PDU session establishment request includes second indication information.

[0183] The specific description of the second indication information can be found in Figure 4 For example, the second indication information may include first information, where the first information is used to indicate that the AMF supports the N26 interface or that the AMF supports intercommunication with 4G.

[0184] For example, in an implicit indication mode, the first information may be the EPS default bearer identifier of the terminal device. For example, when the terminal device determines to initiate a session request to the network, if the AMF supports the N26 interface, it may determine to allocate the EPS default bearer identifier.

[0185] In the displayed indication mode, the first information can be used to directly indicate the existence of an N26 interface between the AMF and the MME of the EPS system.

[0186] The first information may be determined according to the fifth information in S501.

[0187] Furthermore, the second indication information may further include second information, and the second information is used to indicate that the current condition is that the terminal device is in a single registration state.

[0188] Furthermore, the conditions for determining the need to establish an EPS session may also include: the mode of the first session of the terminal device is to maintain continuity, or the DNN indicates a voice network or other network that needs to ensure session continuity.

[0189] Furthermore, the PDU session establishment request message includes a DNN. If the EPS APN corresponding to the DNN is stored on the terminal device, the first indication information may optionally also include an EPS APN.

[0190] Optionally, the AMF can obtain the subscribed UE-AMBR of the user's EPS network.

[0191] Optionally, the AMF may perform SMF selection based on a PDU session establishment request received from the terminal device.

[0192] S503. AMF sends a second PDU session establishment request to SMF+PGW-C based on the first PDU session establishment request, and the second PDU session establishment request message includes first indication information.

[0193] Optionally, the AMF may determine the second indication information as the first indication information. For a specific description of the first indication information, see Figure 4 Related content in .

[0194] Optionally, the second PDU session establishment request is generated according to the first PDU session request.

[0195] The session request of the first PDU may be carried in the second session establishment request message.

[0196] Optionally, the first indication information may also include EPS APN.

[0197] S504. SMF+PGW-C sends a subscription data acquisition request to UDM+HSS, where the subscription data acquisition request includes fourth information, and the fourth information is used to request provision of the subscription data of the first network.

[0198] For a detailed description of the fourth information, please refer to Figure 4 The relevant content in the example.

[0199] For example, after SMF+PGW-C receives the PDU session establishment request message, if it detects that the PDU session establishment request message includes the first indication information, the fourth information can be added to the subscription data acquisition request sent to UDM+HSS.

[0200] The fourth information may include DNN / APN information to indicate that UDM+HSS provides EPS subscription data while providing 5G subscription data. DNN / APN is used to indicate that the subscription data of the corresponding DNN / APN is obtained.

[0201] S505. UDM+HSS sends a subscription data response message to SMF+PGW-C. The subscription data response message includes the second QoS control information.

[0202] The detailed description of the above-mentioned subscription data response message and the second QoS control information can be found in Figure 4 Related content in .

[0203] For example, the second QoS control information may include the EPS subscription data of the terminal device. The EPS subscription data is the subscription data of a specific APN corresponding to a DNN, including the EPS-subscribed QoS text and the subscribed APN-AMBR. For example, the EPS-subscribed QoS text may include: QoS class identifier (QCI), allocation and reservation priority (ARP).

[0204] S506: SMF+PGW-C sends a third PDU session establishment request to PCF+PCRF. The third PDU session request includes the second QoS control information.

[0205] Optionally, SMF+PGW-C can perform PCF selection. After selecting PCF, SMF+PGW-C sends a PDU session establishment request to PCF+PCRF.

[0206] S507. PCF+PCRF sends a third PDU session establishment response to SMF+PGW-C. The third PDU session establishment response corresponds to the third PDU session request. The third PDU session establishment response includes the subscribed first QoS control information.

[0207] The first QoS control information is determined according to the second QoS control information. Figure 4 The relevant contents in will not be repeated here.

[0208] For example, if the network deploys a dynamic PCC architecture, the PDU session establishment response may include an authorized default PCC rule. The authorized default PCC rule includes an authorized 5G default QoS rule and EPS default bearer information. The first QoS control information of the above contract may include the above EPS default bearer information.

[0209] Further, in step S507, the PCF+PCRF determines that a session of the EPS system needs to be established for the terminal device, which may be based on the indication information sent by the received SMF+PGW-C.

[0210] Optionally, the second QoS control parameter may include EPS default bearer QoS parameters. SMF+PGW-C may allocate a 5G QoS flow ID, and store the 5G QoS flow ID and the corresponding QoS flow parameters accordingly. Further, SMF+PGW-C may store the corresponding EPS default bearer information. The EPS default bearer information may include a default EPS bearer ID and a default EPS QoS profile. For example, the above-mentioned default EPS QoS profile includes QCI or ARP. The EPS default bearer information and 5G default QoS flow related information may be stored accordingly. The EPS default bearer information includes the EPS default bearer QoS parameters determined by SMF+PGW-C according to the local policy obtained from UDM+HSS; or the EPS default bearer QoS parameters obtained by SMF+PGW-C from PCF+PCRF;

[0211] S508. SMF+PGW-C sends a fourth session establishment request message to UPF+PGW-U.

[0212] The fourth session establishment request message is a session establishment request of the N4 interface. The N4 interface is a communication interface between the UPF+PGW-U and the SMF+PGW-C.

[0213] S509. UPF+PGW sends a fourth session establishment response message to SMF+PGW-C.

[0214] The fourth session establishment response is a session establishment response message of the N4 interface.

[0215] S510. SMF+PGW-C sends a session management request confirmation message to AMF. The session management request confirmation message includes a second PDU session establishment response message. The second PDU session establishment response message includes the first QoS control information.

[0216] The first QoS control information may include, for example, QoS parameters of the EPS default bearer. Further, the first QoS control information includes a corresponding EPS bearer ID.

[0217] S511. AMF sends a first PDU session request response message to 5G AN. The first PDU session request response message includes first QoS control information.

[0218] For example, the first QoS control information may include the QoS parameters of the EPS default bearer. Furthermore, the first QoS control information may also include the corresponding EPS bearer ID.

[0219] The first PDU session request message is a PDU session request message of the N2 interface. The N2 interface is the communication interface between the AMF and the 5GRAN.

[0220] S512. Optionally, the AN sends an AN-dedicated resource establishment message to the terminal device, where the AN-dedicated resource establishment message includes first QoS control information.

[0221] For example, an air interface resource establishment process may be performed between the AN and the terminal device, and the first QoS control information may be carried in the process.

[0222] S513: The terminal device performs uplink and downlink data transmission with the network device.

[0223] exist Figure 5 In the example, the AMF determines and sends the first indication information according to the second indication information sent by the terminal device, so that the network side determines to generate the EPS system session according to the first indication information, and does not need to establish the EPS system session at any time. The pre-established process is sent under certain conditions, thereby reducing the system overhead as much as possible. The unnecessary overhead caused by initiating the establishment of the EPS system session at any time is reduced.

[0224] See below Figure 6 , Figure 6 The method can be applied to architectures 100-300. Figure 6 The process of generating the first indication information by AMF is shown. Figure 6 The methods include:

[0225] S601. The terminal device sends a first PDU session establishment request to the AMF, where the first PDU session establishment request is used to request to establish a first session of the terminal device in the 5G system.

[0226] For example, the terminal device determines that a session needs to be established, and the terminal device sends the above-mentioned first PDU session establishment request to the AMF.

[0227] S602. AMF sends a second PDU session establishment request to the selected SMF+PGW-C based on the first PDU session establishment request, and the second PDU session establishment request message includes first indication information.

[0228] Optionally, the second PDU session establishment request is generated according to the first PDU session establishment request.

[0229] Optionally, AMF generates first indication information and includes the first indication information in a second PDU session establishment request.

[0230] The first indication information may include first information, and the first information is used to indicate that the AMF supports N26 interface information or the AMF supports intercommunication with 4G.

[0231] For example, in an implicit indication mode, the first information may be the EPS default bearer identifier of the terminal device. For example, when the terminal device determines to initiate a session request to the network, if the AMF supports the N26 interface, it may determine to allocate the EPS default bearer identifier.

[0232] In the displayed indication mode, the first information can be used to directly indicate the existence of an N26 interface between the AMF and the MME of the EPS system.

[0233] For example, since the AMF itself can determine the first information, that is, the interface capability information of N26. Therefore, the AMF can generate the first indication information based on the first information, and the first indication information includes the first information. Further, the AMF can receive the second information from the terminal device, that is, the information that the terminal device is in a single registration state. Therefore, the AMF can also add the above second information to the first indication information. Alternatively, the AMF can optionally determine the indication information based on its own ability to support the N26 interface and the terminal device is in a single registration state, and the indication information is used to instruct the session management function to establish a session of the EPS network, such as EPS bearer information, including QoS parameters and other information.

[0234] S603. SMF+PGW-C sends a subscription data acquisition request to UDM+HSS, where the subscription data acquisition request includes fourth information, and the fourth information is used to request provision of the subscription data of the first network.

[0235] For a detailed description of the fourth information, please refer to Figure 4 The relevant content in the example.

[0236] For example, after SMF+PGW-C receives the PDU session establishment request message, if it detects that the PDU session establishment request message includes the first indication information, the fourth information can be added to the subscription data acquisition request sent to UDM+HSS.

[0237] The fourth information may include DNN / APN information to indicate that UDM+HSS provides EPS subscription data while providing 5G subscription data. DNN / APN is used to indicate that the subscription data of the corresponding DNN / APN is obtained.

[0238] S604, UDM+HSS sends a subscription data response message to SMF+PGW-C. The subscription data response message includes the second QoS control information.

[0239] The detailed description of the above-mentioned subscription data response message and the second QoS control information can be found in Figure 4 Related content in .

[0240] For example, the second QoS control information may include the EPS subscription data of the terminal device. The EPS subscription data is the subscription data of a specific APN corresponding to a DNN, including the EPS-subscribed QoS text and the subscribed APN-AMBR. For example, the EPS-subscribed QoS text may include: QoS class identifier (QCI), allocation and reservation priority (ARP).

[0241] S605, SMF+PGW-C sends a third PDU session establishment request to PCF+PCRF. The third PDU session request includes the second QoS control information.

[0242] Optionally, SMF+PGW-C can perform PCF selection. After selecting PCF, SMF+PGW-C sends a PDU session establishment request to PCF+PCRF.

[0243] S606. PCF+PCRF sends a third PDU session establishment response to SMF+PGW-C. The third PDU session establishment response corresponds to the third PDU session request. The third PDU session establishment response includes the subscribed first QoS control information.

[0244] The first QoS control information is determined according to the second QoS control information. Figure 4 The relevant contents in will not be repeated here.

[0245] For example, if the network deploys a dynamic PCC architecture, the PDU session establishment response may include an authorized default PCC rule. The authorized default PCC rule includes an authorized 5G default QoS rule and EPS default bearer information. The first QoS control information of the above contract may include the above EPS default bearer information.

[0246] Further, in step S507, the PCF+PCRF determines that a session of the EPS system needs to be established for the terminal device, which may be based on the indication information sent by the received SMF+PGW-C.

[0247] Optionally, the second QoS control parameter may include EPS default bearer QoS parameters. SMF+PGW-C may allocate a 5GQoS flow ID, and store the 5G QoS flow ID and the corresponding QoS flow parameters in correspondence. Further, SMF+PGW-C may store the corresponding EPS default bearer information. The EPS default bearer information may include a default EPS bearer ID and a default EPS QoS rule. The EPS default bearer information and the 5G default QoS flow may be stored in correspondence. The EPS default bearer information includes the EPS default bearer QoS parameters obtained by SMF+PGW-C from UDM+HSS and determined according to local policies; or the EPS default bearer QoS parameters obtained by SMF+PGW-C from PCF+PCRF;

[0248] S607. SMF+PGW-C sends a fourth session establishment request message to UPF+PGW-U.

[0249] The fourth session establishment request message is a session establishment request of the N4 interface. The N4 interface is a communication interface between the UPF+PGW-U and the SMF+PGW-C.

[0250] S608. UPF+PGW sends a fourth session establishment response message to SMF+PGW-C.

[0251] The fourth session establishment response is a session establishment response message of the N4 interface.

[0252] S609. SMF+PGW-C sends a session management request confirmation message to AMF. The session management request confirmation message includes a second PDU session establishment response message. The second PDU session establishment response message includes the first QoS control information.

[0253] The first QoS control information may include, for example, QoS parameters of the EPS default bearer. Further, the first QoS control information includes a corresponding EPS bearer ID. Optionally, the QoS control information may also include TFT information.

[0254] S610. AMF sends a first PDU session request response message to 5G AN. The first PDU session request response message includes first QoS control information.

[0255] For example, the first QoS control information may include the QoS parameters of the EPS default bearer. Furthermore, the first QoS control information may also include the corresponding EPS bearer ID.

[0256] The first PDU session request message is a PDU session request message of the N2 interface. The N2 interface is the communication interface between the AMF and the 5GRAN.

[0257] Optionally, in S610, it also includes: the terminal device allocates a default EPS bearer identifier.

[0258] S611. Optionally, the AN sends an AN-dedicated resource establishment message to the terminal device, where the AN-dedicated resource establishment message includes first QoS control information.

[0259] For example, an air interface resource establishment process may be performed between the AN and the terminal device, and the first QoS control information may be carried in the process.

[0260] S612: The terminal device performs uplink and downlink transmission with the network device.

[0261] In the embodiment of the present application, the AMF autonomously generates the first indication information so that the network side determines to generate a session of the EPS system according to the first indication information, and does not need to establish a session of the EPS system at any time. The pre-established process is sent only under certain conditions, thereby reducing the system overhead as much as possible. The unnecessary overhead caused by initiating the establishment at any time is reduced.

[0262] See below Figure 7 , Figure 7 The method can be applied to architectures 100-300. Figure 7 The communication process of session modification is shown. S701, S702, and S703 are three parallel steps. During execution, any one of S701, S702, and S703 can be executed. Figure 7 In the embodiment, the first QoS control information may include the established or modified EPS bearer information. Figure 7 The methods include:

[0263] S701. The terminal device sends a PDU session modification request to the AMF. Further, after receiving the PDU modification request, the AMF sends the PDU session modification request to the SMF+PGW-C. The PDU session modification request is used to indicate the modification of the 5G QoS parameters and the modification of the EPS session bearer parameters.

[0264] For example, when the terminal device determines that an existing PDU session needs to be modified, the terminal device sends a PDU session modification request to the AMF, and the AMF sends a PDU session modification request to the SMF+PGW-C. The terminal device can use this process to modify existing QoS resources, or delete established QoS resources or delete services on QoS resources.

[0265] S702. AF sends a session establishment request to PCF+PCRF and simultaneously establishes an EPS session bearer.

[0266] The session establishment request is a session establishment request of an N5 interface. The N5 interface is a communication interface between the AF and the PCF+PCRF.

[0267] For example, AF can proactively request the network to establish resources for the service, and when necessary, initiate the N5 session establishment process to PCF+PCRF to provide service information and service QoS requirements. When receiving the N5 session request, PCF+PCRF determines based on the instructions sent by the previous SMF request service, and when determining the QoS rules for 5G, it also establishes the QoS rules for EPS, and sends a PDU-CAN modification request containing the determined 5G QoS rules and EPS QoS rules to SMF+PGW-C.

[0268] S703. SMF+PGW-C determines that the QoS parameters of the 5G QoS flow need to be modified, and determines that the QoS parameters of the EPS bearer need to be modified.

[0269] For example, SMF+PGW-C determines to modify the QoS parameters of the 5G QoS flow according to the local policy, and determines to modify the QoS parameters of the EPS bearer at the same time according to the first indication information received during the session establishment process.

[0270] S704. The PDU session modification process is executed between SMF+PGW-C and PCF+PCRF.

[0271] The PDU session modification process is similar to the PDU session establishment process, which can be found in Figure 5 S506-S507 in Figure 6 The relevant contents of S605-S606 in.

[0272] S705. SMF+PGW-C stores or updates the QoS parameters of the EPS bearer.

[0273] For example, if the session modification process initiated by the terminal device and the network is used to modify the parameters of an existing 5G QoS flow, SMF+PGW-C saves the updated new 5G QoS flow parameters and the corresponding EPS bearer QoS parameters. If a new 5G QoS flow is created when the terminal device and the network initiate a session modification, the network determines to establish a dedicated EPS bearer, and when SMF+PGW-C saves the new 5G QoS flow information, it also saves the corresponding established dedicated EPS bearer.

[0274] S706. SMF+PGW-C sends a PDU session modification request to AMF, where the PDU session modification request includes the EPS bearer information to be established or modified.

[0275] For example, the session management request sent by SMF+PGW-C to AMF includes a PDU session modification request, and the PDU session modification request includes the established or modified EPS bearer information.

[0276] S707. AMF sends a PDU session request to the (R)AN. The PDU session request includes information about the established or modified EPS bearer.

[0277] The PDU session request in S707 is a PDU session request of the N2 interface, which is a communication interface between the AMF and the AN.

[0278] S708. The AN sends an AN dedicated resource modification message to the terminal device, where the AN dedicated resource modification message includes established or modified EPS bearer information.

[0279] For example, the terminal device and the AN perform an AN dedicated resource modification process, in which the AN sends the established or modified EPS bearer information to the terminal device. If the terminal device determines that the EPS bearer information is newly created, an EPS bearer identifier is allocated to the bearer information.

[0280] S709. AN sends a PDU session request confirmation message to AMF.

[0281] The PDU session request confirmation message in S709 is a PDU session confirmation message of the N2 interface.

[0282] For example, the AN sends an N2 PDU session request confirmation to the AMF. If the terminal device is assigned an EPS bearer identifier, the PDU session request confirmation message may include the EPS bearer identifier.

[0283] S710. AMF sends a session rights request to SMF+PGW-C.

[0284] Optionally, if the terminal device is allocated an EPS bearer identifier, the session rights request includes the EPS bearer identifier.

[0285] In the embodiment of the present application, during the process of modifying the existing 5G session, the bearer parameters of the EPS system can be modified according to network needs. In other words, only when specific conditions are met, the system will modify and establish the bearer parameters of the EPS system during the process of modifying the 5G session, thereby avoiding unnecessary overhead and improving communication efficiency.

[0286] exist Figure 5-Figure 7In the example, when the terminal device accesses the 5G network and establishes a session with the 5G network or establishes a dedicated QoS flow, the network side can determine whether to establish a session of the EPS system according to whether the network supports the N26 interface, the registration mode of the terminal device and the mode of the session. For example, during the session establishment process, the SMF determines to obtain the subscribed context of the 5G session from the UDM+HSS while obtaining the subscribed PDN context of the EPS system based on the fourth information received. The PDN context includes the first QoS control information, such as EPS subscribed QoS rules (EPS subscribed QoS profile), subscribed access point name aggregate maximum bit rate (subscribed APN-AMBR), etc. SMF+PGW-C provides the authorized default 5G QoS rules and the authorized EPS default bearer information to the terminal device. When deploying policy and charging control (PCC), SMF+PGW-C interacts with PCF to obtain the authorized default 5G QoS rules and the authorized EPS default bearer information. Otherwise, SMF can perform authorization according to local policy.

[0287] Optionally, during the establishment of a dedicated bearer initiated by the network or a dedicated bearer initiated by the terminal device, the PCF / SMF+PGW-C determines the QoS rules of the EPS system while determining the 5G QoS rules according to the indication information. The SMF+PGW-C determines whether to establish a new EPS bearer bearer context. When a new EPS bearer needs to be established, the EPS bearer information is sent to the terminal device and the EPS bearer ID assigned by the terminal device is received.

[0288] Optionally, when a QoS flow is deleted or modified, the network side may synchronously modify or delete the corresponding EPS bearer information.

[0289] See below Figure 8 , Figure 8 The method can be applied to architectures 100-300. Figure 8 shows the communication process of the terminal device registering to the network, and shows the process of the terminal device obtaining the fifth information when registering to the network, Figure 8 The methods include:

[0290] S801. The terminal device sends a registration request (register request) to the (R)AN. Correspondingly, the (R)AN receives the registration request.

[0291] S802. (R)AN sends the above registration request to AMF.

[0292] For example, the (R)AN may select an AMF and send the above registration request to the selected AMF.

[0293] S803. AMF sends a registration accept message to the terminal device through the (R)AN. The registration accept message includes the fifth information.

[0294] For details about the fifth information, please refer to Figure 4 For example, the fifth information may be used to indicate that the mobility management entity of the second network has a communication interface with the mobility management entity of the first network. For example, the fifth information is used to indicate that the current network supports the N26 interface between the AMF and the MME.

[0295] In the embodiment of the present application, the AMF carries the fifth information when sending the registration acceptance message to the terminal device, and the fifth information is used to indicate that the mobility management entity of the second network has a communication interface with the mobility management entity of the first network, so as to facilitate communication according to the fifth information, thereby improving communication efficiency.

[0296] Combination of the above Figures 1 to 8 The communication method of the embodiment of the present application is described in detail. Figures 9 to 14 The network elements and terminal devices of the embodiments of the present application are described in detail.

[0297] Fig. 9 FIG. 9 is a schematic block diagram of a network element 900 according to an embodiment of the present application. It should be understood that the network element 900 can execute Figures 1 to 8 The steps performed by the first network element in the method are not described in detail here to avoid repetition. The network element 900 includes: a receiving unit 910, an acquiring unit 920 and a sending unit 930.

[0298] The receiving unit 910 is configured to receive first indication information from a second network element, where the first indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device;

[0299] The acquiring unit 920 is configured to acquire, after receiving the first indication information, first quality of service QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through the second network;

[0300] The sending unit 930 is used to send the first QoS control information to the second network element.

[0301] Fig.10FIG. 1 is a schematic block diagram of a network element 1000 according to an embodiment of the present application. It should be understood that the network element 1000 can execute Figures 1 to 8 The steps performed by the second network element in the method are not described in detail here to avoid repetition. The network element 1000 includes: a sending unit 1010 and a receiving unit 1020.

[0302] The sending unit 1010 is used to send first indication information to the first network element, where the first indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device;

[0303] The receiving unit 1020 is configured to receive first quality of service QoS control information of a first session of the terminal device from the first network element, wherein the first session is a session established by the terminal device through the second network.

[0304] Fig.11 is a schematic block diagram of a terminal device 1100 according to an embodiment of the present application. It should be understood that the terminal device 1100 is capable of executing Figures 1 to 8 The steps performed by the terminal device in the method are not described in detail here to avoid repetition. The terminal device 1100 includes: a sending unit 1110 and a receiving unit 1120.

[0305] The sending unit 1110 is used to send second indication information to the second terminal device, where the second indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device;

[0306] The receiving unit 1120 is configured to receive first quality of service QoS control information of a first session of the terminal device, wherein the first session is a session established by the terminal device through a second network.

[0307] Fig.12 1 is a schematic block diagram of a network element 1200 according to an embodiment of the present application. It should be understood that the network element 1200 can execute Figures 1 to 8 The steps performed by the first network element in the method are not described in detail here to avoid repetition. The network element 1200 includes:

[0308] A memory 1210, used for storing programs;

[0309] Communication interface 1220, used to communicate with other devices;

[0310] The processor 1230 is used to execute the program in the memory 1210. When the program is executed, the processor 1230 is used to receive first indication information from the second network element through the communication interface 1220, wherein the first indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device; and after receiving the first indication information, obtain first quality of service QoS control information of the first session of the terminal device, wherein the first session is a session established by the terminal device through the second network; and send the first QoS control information to the second network element through the communication interface 1220.

[0311] Fig.13 1 is a schematic block diagram of a network element 1300 according to an embodiment of the present application. It should be understood that the network element 1300 can execute Figures 1 to 8 The steps performed by the second network element in the method are not described in detail here to avoid repetition. The network element 1300 includes:

[0312] A memory 1310, used for storing programs;

[0313] Communication interface 1320, used to communicate with other devices;

[0314] The processor 1330 is used to execute the program in the memory 1310. When the program is executed, the processor 1330 is used to send first indication information to the first network element through the communication interface 1320, wherein the first indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device; and receive first quality of service QoS control information of the first session of the terminal device from the first network element through the communication interface 1320, wherein the first session is a session established by the terminal device through the second network.

[0315] Fig.14 is a schematic block diagram of a terminal device 1400 according to an embodiment of the present application. It should be understood that the terminal device 1400 is capable of executing Figures 1 to 8 The various steps performed by the terminal device in the method are not described in detail here to avoid repetition. The terminal device 1400 includes:

[0316] A memory 1410, used for storing programs;

[0317] Communication interface 1420, used to communicate with other devices;

[0318] Processor 1430 is used to execute the program in memory 1410. When the program is executed, the processor 1430 is used to send second indication information to the second terminal device through the communication interface 1420, wherein the second indication information is used to indicate that current conditions support establishing a session of the first network for the terminal device; and receive first quality of service QoS control information of the first session of the terminal device through the communication interface 1420, wherein the first session is a session established by the terminal device through the second network.

[0319] Those of ordinary skill 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 to be beyond the scope of this application.

[0320] Those skilled in the art can 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.

[0321] In the several embodiments provided in the present 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, such as 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.

[0322] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0323] 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.

[0324] 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 can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network element, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0325] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, applied in a process of establishing or modifying a session in a second network, characterized in that: include: The first network element receives first indication information from a second network element in the second network, where the first indication information is used to indicate supporting a communication interface between a mobility management entity of the second network and a mobility management entity of the first network and supporting intercommunication between the first network and the second network, and the first network element is used to provide a session management function for the first network and the second network; The first network element obtains, according to the first indication information, first quality of service QoS control information for controlling transmission services in the first network; The first network element sends the first QoS control information to the terminal device through the second network element.

2. The communication method according to claim 1, characterized in that: The second network element is a mobility management entity in the second network.

3. The communication method according to claim 1, characterized in that: The communication interface is an N26 interface, the first network is an evolved packet system EPS, and the second network is a 5G network.

4. The communication method according to claim 1, wherein: The method further comprises: The first network element receives a bearer identifier of the bearer of the first network of the terminal device from the second network element.

5. The communication method according to claim 1, wherein: The first QoS control information includes the QoS parameters of the bearer of the first network and the EPS bearer identifier.

6. The communication method according to claim 5, characterized in that: The first QoS control information further includes at least one of the following: Packet filter, packet filter priority information.

7. The communication method according to any one of claims 1 to 6, characterized in that: The first network element receiving first indication information from the second network element includes: The first network element receives a management request message for a session of the first network from the second network element, where the management request message includes the first indication information.

8. The communication method according to claim 7, characterized in that: The management request message is used to request to establish or modify a session of the second network.

9. The communication method according to any one of claims 1 to 6, characterized in that: The first network element sending the first QoS control information to the terminal device through the second network element includes: The first network element sends a session establishment acceptance message or a session modification message to the terminal device through the second network element, and the session establishment acceptance message or the session modification message carries the first QoS control information.

10. A communication method, applied in a process of establishing or modifying a session in a second network, characterized in that: include: The second network element in the second network sends first indication information to the first network element, where the first indication information is used to indicate support for a communication interface between a mobility management entity of the second network and a mobility management entity of the first network and support for intercommunication between the first network and the second network; The second network element receives, from the first network element, first quality of service (QoS) control information for controlling a service transmitted in the first network; The second network element sends the first QoS control information to the terminal device.

11. The communication method according to claim 10, characterized in that: The method further comprises: The second network element receives second indication information from the terminal device, where the second indication information is used to indicate that current conditions support establishing a bearer of the first network for the terminal device; The second network element determines the first indication information according to the second indication information.

12. The communication method according to claim 10, characterized in that: The second network element is a mobility management entity in the second network.

13. The communication method according to claim 10, characterized in that: The communication interface is an N26 interface, the first network is an evolved packet system EPS, and the second network is a 5G network.

14. The communication method according to claim 10, characterized in that: Also includes: The second network element sends the bearer identifier of the bearer of the first network of the terminal device to the first network element.

15. The communication method according to claim 10, characterized in that: The first QoS control information includes the QoS parameters of the bearer of the first network and the EPS bearer identifier.

16. The communication method according to claim 15, characterized in that: The first QoS control information also includes at least one of the following: a packet filter, and priority information of the packet filter.

17. The communication method according to any one of claims 10 to 16, characterized in that: The second network element sending first indication information to the first network element includes: The second network element sends a management request message of a first session to the first network element, where the management request message of the first session includes the first indication information.

18. The communication method according to claim 17, characterized in that: The management request message is used to request to establish or modify a session of the second network.

19. The communication method according to any one of claims 10 to 16, characterized in that: The second network element sending the first QoS control information to the terminal device includes: The second network element sends a session establishment acceptance message or a session modification message to the terminal device, and the session establishment acceptance message or the session modification message carries the first QoS control information.

20. A communication method, characterized in that: The process of establishing or modifying a session in a second network includes: The terminal device sends indication information to the second network element in the second network, where the indication information is used to indicate that current conditions support establishing a bearer of the first network for the terminal device; The terminal device receives first quality of service (QoS) control information for controlling transmission services in the first network.

21. The communication method according to claim 20, characterized in that: The indication information includes first information, where the first information is used to indicate that the current condition is that a communication interface exists between the mobility management entity of the second network and the mobility management entity of the first network.

22. The communication method according to claim 20, characterized in that: The first QoS control information includes the QoS parameters of the bearer of the first network and the EPS bearer identifier.

23. The communication method according to claim 22, characterized in that: The first QoS control information further includes at least one of the following: Packet filter, packet filter priority information.

24. The communication method according to any one of claims 20 to 23, characterized in that: The first QoS control information is carried in a second session management message received by the terminal device, and the second session management message is used to instruct modification or establishment of QoS control information in a second network of the terminal device.

25. A network element, characterized in that: include: Memory, for storing computer instructions; A processor is used to execute computer instructions stored in the memory. When the computer instructions are executed, the processor is used to execute the method as described in any one of claims 1 to 9.

26. A network element, characterized in that: include: Memory, for storing computer instructions; A processor, configured to execute computer instructions stored in the memory; when the computer instructions are executed, the processor is configured to execute the method as claimed in any one of claims 10 to 19.

27. A terminal device, characterized in that: include: Memory, for storing computer instructions; A processor, configured to execute computer instructions stored in the memory; when the computer instructions are executed, the processor is configured to execute the method as claimed in any one of claims 20 to 24.

28. A communication system, characterized in that: include: A network element as claimed in claim 25 and a network element as claimed in claim 26.

29. A communication system, characterized in that: include: The network element as claimed in claim 25; The network element as claimed in claim 26 and the terminal device as claimed in claim 27.

30. A computer storage medium, characterized in that The method comprises computer instructions, which, when executed on a computer, cause the computer to execute the method according to any one of claims 1 to 9.

31. A computer storage medium, characterized in that The method comprises computer instructions, which, when executed on a computer, cause the computer to execute the method according to any one of claims 10 to 19.

32. A computer storage medium, characterized in that The method comprises computer instructions, which, when executed on a computer, cause the computer to perform the method according to any one of claims 20 to 24.

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