CN113709904B

CN113709904B - Connection establishment method, device and system

Info

Publication number: CN113709904B
Application number: CN202010444377.1A
Authority: CN
Inventors: 徐艺珊; 诸华林
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2024-04-09
Anticipated expiration: 2040-05-22
Also published as: CN113709904A; WO2021233235A1

Abstract

The embodiment of the application provides a method, a device and a system for establishing connection. The method comprises the steps that a first terminal device receives a first message of a second terminal, and the first message requests to establish a first connection between the second terminal device and a data network; the first terminal equipment forwards the first message to the core network through a control plane between the first terminal equipment and the core network so as to acquire a response of the core network to accept the request to establish the first connection; the first terminal device establishes or selects a second connection for transmitting data of the first connection; wherein the second connection is a connection between the first terminal device and the data network. The realization complexity of the first terminal equipment and the second terminal equipment is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

Description

Connection establishment method, device and system

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a method, an apparatus, and a system for connection establishment.

Background

The third generation partnership project (3rd generation partnership project,3GPP) standard group promulgates a fifth generation mobile communication technology (5G) network architecture. The 5G Network architecture supports a home gateway (Residential Gateway, RG) accessing a 5G core Network via a radio access Network or a fixed broadband access Network, and further accessing a Data Network (DN) connected to the 5G core Network. In this architecture, the RG is also a type of 5G terminal for 5G networks. Based on the architecture, a terminal with a 5G function (such as a computer, a mobile phone, an internet of things device and the like supporting the 5G function) can access the 5G system through the RG to establish a PDU session. The above communication scheme is called that a plurality of terminals communicate through concatenation. According to the definition of the 3GPP standard, when a terminal with a 5G function accesses a 5G system through an RG, an IP security (IPSec) tunnel needs to be established between the terminal and the 5G system. The IPSec tunnel is carried on the user plane of the RG, and both control plane signaling interaction and user plane data between the terminal and the 5G core network need to be transmitted through the IPSec tunnel.

In practical deployment, due to environmental limitations, such as signal problems (e.g. a terminal device with 5G function is far away from or blocked from a 3GPP or fixed network access point, and cannot find a suitable RG deployment location), or for convenience of management, a terminal with 5G function is sometimes required to access a 5G system through two home gateway devices (e.g. RG or Customer Premise Equipment, CPE). At this time, the intermediate home gateway device also needs to access the 5G system through another home gateway device. The intermediate home gateway can also be regarded as a 5G-capable terminal device. When the home gateway requests to establish the PDU session, an IP security tunnel needs to be established between the home gateway and the 5G system according to a scheme defined by the 3GPP standard. Similarly, when the terminal equipment with the 5G function at the end establishes the PDU session, an IP security tunnel needs to be established between the terminal equipment and the 5G system. Therefore, a scene of superposition of two layers of IPSec tunnels can appear, the realization cost and complexity of the home gateway are increased, and the data transmission path becomes roundabout, so that the throughput rate of data transmission is reduced, and the communication time delay is caused.

Disclosure of Invention

The embodiment of the application is used for providing a method, a device and a system for establishing connection, which are used for reducing the time delay when a plurality of terminals are cascaded to communicate.

In order to achieve the above object, the embodiments of the present application provide the following solutions.

In a first aspect, embodiments of the present application provide a method for connection establishment. The method comprises the following steps:

the method comprises the steps that a first terminal device receives a first message of a second terminal, and the first message requests to establish a first connection between the second terminal device and a data network; the first terminal equipment forwards the first message to the core network through a control plane between the first terminal equipment and the core network so as to acquire a response of the core network to accept the request to establish the first connection; the first terminal device establishes or selects a second connection for transmitting data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

By the method for establishing the connection provided in the first aspect, the first terminal device forwards the first message of the second terminal device to the core network through the control surface between the first terminal device and the core network, and the first terminal device establishes or selects the second connection of the first terminal device for transmitting the data of the first connection of the second terminal device, so that the implementation complexity of the first terminal device and the second terminal device is simplified, the roundabout path for transmitting the signaling and the data is reduced, and the communication delay is reduced.

As a possible implementation manner, the method further includes: the first terminal obtains the establishment parameters of the first connection determined by the core network through the control plane; the first terminal device establishes or selects a second connection for transmitting data of the first connection, comprising: the first terminal establishes or selects the second connection according to the establishment parameters of the first connection.

By the connection establishment method provided by the possible implementation manner, the first terminal device establishes or selects the second connection of the first terminal device according to the establishment parameter of the first connection acquired from the core network, and is used for transmitting the data of the first connection of the second terminal device, so that the implementation complexity of the first terminal device and the second terminal device is simplified, the roundabout path for transmitting signaling and data is reduced, and the communication time delay is reduced.

As a possible implementation manner, the setting parameters of the first connection include: the core network determines network slice selection auxiliary information NSSAI of the first connection; or the data network name DNN of the first connection determined by the core network.

As another possible implementation manner, the method further includes: the first terminal obtains a request establishment parameter of the first connection requested by the second terminal; the first terminal device establishes or selects a second connection for transmitting data of the first connection, comprising: the first terminal establishes or selects the second connection according to the request establishment parameter of the first connection.

By the method for establishing the connection provided by the possible implementation manner, the first terminal device establishes or selects the second connection of the first terminal device according to the establishment parameter of the first connection acquired from the second terminal device, and is used for transmitting the data of the first connection of the second terminal device, so that the implementation complexity of the first terminal device and the second terminal device is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

As a possible implementation, the request setup parameters of the first connection include: network slice selection assistance information nsai for the first connection requested by the second terminal; or, the data network name DNN of the first connection requested by the second terminal.

As a possible implementation manner, the first message is a first non-access stratum NAS message, and the forwarding, by the first terminal device, the first message to the core network through a control plane between the first terminal device and the core network includes: the first terminal device sends a second NAS message to a first control plane network element serving the first terminal, where the second NAS message includes the first NAS message, so that the first control plane network element sends the first NAS message to a second control plane network element serving the second terminal device.

As a possible implementation, the first terminal device receives the first data packet of the first connection from the second terminal device; the first terminal device converts the first data packet into a second data packet of the second connection; the first terminal device sends the second data packet over the second connection.

As a possible implementation manner, the first terminal device converts the first data packet into the second data packet of the second connection, including: the first terminal device sets the source IP address of the first data packet to the IP address of the first terminal device allocated for the second connection.

As a possible implementation, the first terminal device receives a third data packet of the second connection; the first terminal device converts the third data packet into a fourth data packet of the first connection; the first terminal device sends the fourth data packet to the second terminal device.

As a possible implementation manner, the first terminal device converts the third data packet into a fourth data packet of the first connection, including: the first terminal device sets the destination IP address of the third data packet to the IP address of the second terminal allocated for the first connection.

By the method for establishing the connection provided by the possible implementation manner, the first terminal device uses the second connection of the first terminal device to transmit the data of the first connection of the second terminal device, so that the implementation complexity of the first terminal device and the second terminal device is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

As a possible implementation, the first connection is a first protocol data unit PDU session of the first terminal and the data network, and the second connection is a second PDU session of the second terminal and the data network.

As a possible implementation, the first connection is identical to the data network name DNN or the network slice selection assistance information nsai of the second connection.

In a second aspect, embodiments of the present application provide a method for connection establishment. The method comprises the following steps:

the first control surface network element acquires a first message of a second terminal device through a second control surface network element of the first terminal device, and the first message requests to establish a first connection between the second terminal device and a data network; the first control plane network element sends the first message to a third control plane network element serving the second terminal device to obtain a response of the core network to the reception request to establish the first connection.

By the method for establishing the connection provided in the second aspect, the first control plane network element obtains the first message of the second terminal device through the control plane of the first terminal device, and obtains the response of the core network to the receiving request for establishing the first connection, so as to support the establishment of the first connection establishment request of the second terminal device. The above process simplifies the implementation complexity of the first terminal device and the second terminal device, reduces the detour path of signaling transmission, and reduces the communication delay.

As a possible implementation manner, the first control plane network element obtains the establishment parameter of the first connection determined by the core network; the first control plane network element sends the establishment parameters of the first connection to the first terminal device so as to enable the first terminal device to establish or select a second connection for transmitting the data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

By the method for establishing the connection provided in the second aspect, the first control plane network element transmits a connection establishment request between the second terminal device and the core network and corresponds to the connection establishment request through the second control plane network element of the first terminal device, and sends the establishment parameter of the first connection determined by the core network to the first terminal device, so as to support the first terminal device to establish or select the second connection of the first terminal device, and the second control plane network element is used for transmitting the data of the first connection. The above process simplifies the implementation complexity of the first terminal device and the second terminal device, reduces the detour path of signaling and data transmission, and reduces the communication delay.

As a possible implementation, the first control plane network element participates in the establishment of the second connection.

As a possible implementation manner, the first message is a first non-access stratum NAS message, and the first control plane network element acquires, through a control plane with the first terminal device, the first message of the second terminal device, including: the first control plane network element receives a second NAS message from the first terminal device, the second NAS message including the first NAS message.

As a possible implementation manner, the second NAS message further includes a first identifier of the second terminal apparatus; the method further comprises the steps of: acquiring a second identifier of the second terminal equipment according to the first identifier; the first control plane network element sending the first message to a second control plane network element serving the second terminal device, comprising: the first control plane network element sends the first message and the second identifier to the second control plane network element.

In a third aspect, embodiments of the present application provide a third method for connection establishment. The method comprises the following steps:

the second terminal device sends a first session establishment request parameter to the first terminal device to enable the first terminal device to establish or select a second connection for transmitting data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

By the method for establishing the connection provided by the third aspect, the second terminal device sends the first session establishment request parameter to the first terminal device, so that the first terminal device can select or establish the second connection of the first terminal device according to the first session establishment request parameter, and the second connection is used for transmitting the data of the first connection of the second terminal device, thereby simplifying the implementation complexity of the first terminal device and the second terminal device, reducing the roundabout path of data transmission, and reducing the communication delay.

In a fourth aspect, embodiments of the present application provide a communications apparatus comprising a processor configured to read and execute instructions from a memory to implement a method as in the first aspect or any possible implementation.

In a fifth aspect, embodiments of the present application provide a communications apparatus comprising a processor configured to read and execute instructions from a memory to implement a method as in the second aspect or any possible implementation.

In a sixth aspect, embodiments of the present application provide a communications apparatus comprising a processor configured to read and execute instructions from a memory to implement a method as in the third aspect or any possible implementation manner.

In a seventh aspect, embodiments of the present application provide a program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to implement a method as in the first aspect or any one of the possible implementations.

In an eighth aspect, embodiments of the present application provide a program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to implement the method as in the second aspect or any one of the possible implementations.

In a ninth aspect, embodiments of the present application provide a program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to implement a method as in the third aspect or any one of the possible implementations.

In a tenth aspect, embodiments of the present application provide a computer readable storage medium, comprising the program product of the seventh aspect.

In an eleventh aspect, embodiments of the present application provide a computer readable storage medium, including the program product of the eighth aspect.

In a twelfth aspect, embodiments of the present application provide a computer-readable storage medium, comprising the program product of the ninth aspect.

In a thirteenth aspect, embodiments of the present application provide a method for connection establishment. The method comprises the following steps:

the method comprises the steps that a first terminal device receives a first message of a second terminal, and the first message requests to establish a first connection between the second terminal device and a data network; the first terminal equipment forwards the first message to the core network through a control plane between the first terminal equipment and the core network so as to establish the connection between the user plane network element of the first connection and the data network; the first terminal equipment establishes or selects a second connection for transmitting data of the first connection, wherein the second connection is a connection of the first terminal equipment and a data network where a user plane network element of the first connection is located; wherein the connection between the user plane network element of the first connection and the user plane network element of the second connection is established by means of the establishment of the first connection and the establishment or modification of the second connection.

By the method for establishing a connection provided in the thirteenth aspect, the first terminal device forwards the first message of the second terminal device to the core network through the control plane between the first terminal device and the core network, and the first terminal device establishes or selects the second connection of the first terminal device, where the connection between the second connection and the user plane network element of the first connection and the user plane network element of the second connection is used for transmitting the data of the first connection of the second terminal device, thereby simplifying the implementation complexity of the first terminal device and the second terminal device, reducing the detour path of signaling and data transmission, and reducing the communication delay.

As a possible implementation manner, the method further includes: the first terminal obtains the data network where the user plane network element of the first connection is located through the control plane.

As a possible implementation manner, the method further includes: the first terminal obtains a request establishment parameter of the first connection requested by the second terminal; the first terminal device establishes or selects a second connection for transmitting data of the first connection, comprising: the first terminal establishes or selects the second connection according to the request establishment parameter of the first connection.

As a possible implementation manner, the method further includes: the first terminal device receiving a first data packet of the first connection from the second terminal device; the first terminal device sends a second data packet of the second connection through the second connection; wherein the second data packet includes the first data packet.

As a possible implementation manner, the method further includes: the first terminal device receives a third data packet of the second connection; the first terminal equipment acquires a fourth data packet of the first connection from the third data packet; the first terminal device sends the fourth data packet to the second terminal device.

As a possible implementation manner, the first connection is a first protocol data unit PDU session of the first terminal and the data network, and the second connection is a second PDU session of the data network where the second terminal and the user plane network element of the second connection are located.

In a fourteenth aspect, an embodiment of the present application provides a method for connection establishment, including:

the first control surface network element acquires a first message of the second terminal equipment through a control surface of the first terminal equipment, wherein the first message requests to establish a first connection between the second terminal equipment and a data network; the first control plane network element sends the first message to a second control plane network element serving the second terminal device; the first control plane network element receives a second message from the first terminal device, the second message requesting to establish a second connection of the first terminal device with the user plane network element of the first connection; the second connection is used for transmitting the data packet of the first connection; and acquiring the tunnel endpoint identifier of the user plane network element of the first connection and the tunnel endpoint identifier of the user plane network element of the second connection so as to enable connection between the user plane network element of the first connection and the user plane network element of the second connection to be established.

By the method for connection establishment provided in the fourteenth aspect, the first control plane network element transmits a message between the second terminal device and the core network through the control plane of the first terminal device, and the first control plane network element establishes a connection between the user plane network element of the first connection and the user plane network element of the second connection, so as to transmit data of the first connection of the second terminal device. The above process simplifies the implementation complexity of the first terminal device and the second terminal device, reduces the detour path of signaling and data transmission, and reduces the communication delay.

As a possible implementation manner, the method further includes: the first control plane network element acquires the establishment parameters of the first connection determined by the core network; the first control plane network element sends the establishment parameter of the first connection to the first terminal device to enable the first terminal device to establish or select the second connection.

In a fifteenth aspect, embodiments of the present application provide a communications apparatus comprising a processor configured to read and execute instructions from a memory to implement a method as in the thirteenth aspect or any possible implementation.

In a sixteenth aspect, an embodiment of the present application provides a communications apparatus comprising a processor configured to read and execute instructions from a memory to implement a method as in the fourteenth aspect or any one of the possible implementations.

In a seventeenth aspect, embodiments of the present application provide a program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to implement the method as in the thirteenth aspect or any possible implementation.

In an eighteenth aspect, embodiments of the present application provide a program product comprising instructions which, when run on a communications apparatus, cause the communications apparatus to implement the method as in the fourteenth aspect or any one of the possible implementations.

In a nineteenth aspect, embodiments of the present application provide a computer readable storage medium comprising a program product as in the seventeenth aspect.

In a twentieth aspect, embodiments of the present application provide a computer-readable storage medium comprising the program product of the eighteenth aspect.

In the embodiment of the application, the first terminal device transmits the message between the second terminal device and the core network through the control surface between the first terminal device and the core network, and the first terminal device establishes or selects the second connection of the first terminal device for transmitting the data of the first connection of the second terminal device, so that the implementation complexity of the first terminal device and the second terminal device is simplified, the roundabout path for transmitting the signaling and the data is reduced, and the communication time delay is reduced.

Drawings

FIG. 1 is a schematic diagram of a 3GPP defined 5G network architecture;

fig. 2 is a schematic diagram of a UE accessing a 5G core network through an RG;

fig. 3 is a schematic diagram of an architecture for data transmission by an RG through a PDU session of a CPE;

fig. 4 is a schematic diagram of an architecture in which an RG performs data transmission through a PDU session of a CPE and a PDU session of the RG;

FIG. 5 is a schematic diagram of a method of connection establishment based on the architecture of FIG. 3;

fig. 6 is a schematic diagram of a CPE based on the architecture of fig. 3 obtaining a network response to an RG PDU session establishment;

fig. 7 is a schematic diagram of a CPE establishing a CPE PDU session for transmitting RG PDU session data based on one of the CPEs of the architecture of fig. 3;

FIG. 8 is a schematic diagram of another method of connection establishment based on the architecture of FIG. 3;

fig. 9 is a schematic diagram of a CPE PDU session established for transmitting RG PDU session data based on another CPE of the architecture of fig. 3;

FIG. 10 is a schematic diagram of a method of connection establishment based on the architecture of FIG. 4;

fig. 11 is a schematic diagram of a CPE based on the architecture of fig. 4 obtaining a network response to an RG PDU session establishment;

fig. 12 is a schematic diagram of a CPE establishing a CPE PDU session for transmitting RG PDU session data based on one of the CPEs of the architecture of fig. 4;

FIG. 13 is a schematic diagram of a CPE AMF based architecture of FIG. 4 establishing a user plane connection between a CPE PDU session and an RG PDU session;

FIG. 14 is a schematic diagram of another method of connection establishment based on the architecture of FIG. 4;

fig. 15 is a schematic diagram of a CPE PDU session established for transmitting RG PDU session data based on another CPE of the architecture of fig. 4;

fig. 16 is a schematic diagram of a user plane connection between a CPE PDU session and an RG PDU session established based on another CPE AMF of the architecture of fig. 4.

Fig. 17 is a schematic diagram of a method of connection establishment at a first terminal device side based on the architecture of fig. 3;

fig. 18 is a schematic diagram of a method of connection establishment at a second terminal device side based on the architecture of fig. 3;

Fig. 19 is a schematic diagram of a method of connection establishment at a first control plane network element side based on the architecture of fig. 3;

FIG. 20 is a schematic diagram of a communication device;

fig. 21 is a schematic diagram of a method of connection establishment at a first terminal device side based on the architecture of fig. 4;

fig. 22 is a schematic diagram of a method of connection establishment at the first control plane network element side based on the architecture of fig. 4;

FIG. 23 is a schematic diagram of a terminal device;

fig. 24 is a schematic diagram of a communication device.

Detailed Description

The following describes embodiments of the present application with reference to the drawings. The following embodiments are presented by way of example in terms of a 5G network. It should be noted that the technical solution of the present application may also be applicable to an evolved 4G network, or a future 6G network, etc.

The 3GPP standard group developed a next generation mobile communication network architecture (Next Generation System), referred to as a 5G network architecture, at the end of 2016, as shown in fig. 1. In fig. 1, a UE (User Equipment) accesses a core network through a (R) AN. Wherein the (R) AN comprises a 3GPP RAN and a non-3 GPP access network, and the non-3 GPP access network comprises a WLAN, a wire line and the like. The core network comprises a control plane function network element and a user plane function network element. Wherein the control plane function network elements comprise an access and mobility management function (Access and Mobility Management Function, AMF), a session management function (Session Management Function, SMF), an authentication server function (Authentication Server Function, AUSF), a unified user data management (Unified Data Management, UDM) and a policy control function (Policy Control function, PCF). Wherein the AMF is mainly responsible for registration authentication when the user accesses and mobility management of the user. The SMF is mainly responsible for establishing corresponding session connection at the network side when a user initiates a service, providing specific service for the user, and transmitting a data message forwarding strategy, a QoS control strategy and the like to a user plane function network element. The AUSF is mainly responsible for authenticating the ue and determining the validity of the ue. The UDM is mainly used for storing user equipment subscription data. The PCF is mainly used to issue traffic related policies to the AMF or SMF. The user plane function network element is mainly a user plane function (User Plane Function, UPF) and is mainly responsible for forwarding packet data messages, quality of service (Quality of Service, qoS) control, charging information statistics and the like. The UE may request establishment of a user plane connection with a Data Network (DN) through a 5G Network, e.g., the UE may request establishment of a protocol Data unit Session (Protocol Data Unit Session, PDU Session). After the PDU Session of the UE is established, the uplink data packet of the UE is sent to the UPF through the (R) AN, and then sent to the DN by the UPF. Correspondingly, after receiving the downlink data packet of the UE from the DN, the UPF sends the downlink data packet to the UE through the (R) AN.

The 5G network architecture supports fixed terminal home gateways (Residential Gateway, RG) accessing the core network from the (R) AN. Further, the 5G network architecture also supports the UE to access the core network through the RG, as shown in fig. 2. In fig. 2, N3GF (Non-3 GPP Gateway Function) provides an access gateway function for a UE to access a core network from a Non-3GPP access network, which may correspond to the TNGF (Trusted Non-3GPP Gateway Function) of a Trusted Non-3GPP access architecture, or the N3IWF (Non-3 GPP InterWorking Function) of a Non-Trusted Non-3GPP access architecture.

It should be noted that, in the embodiment of the present application, the user plane function, the access and mobility management function, the session management function, and the like are just one name, and the name does not limit the device itself. In 5G networks and other networks in the future, network elements or entities corresponding to the user plane function, the access and mobility management function, the session management function, etc. may also be other names, which are not specifically limited in the embodiments of the present application. For example, the user plane function may be replaced by UP, and the like, and is described in detail herein, and will not be repeated.

It should be noted that, in addition to the functions in the embodiments of the present application, the user plane function, the access and mobility management function, the session management function, and the like may also have other functions, which are not specifically limited in the embodiments of the present application. In addition, the user plane function, the access and mobility management function, the session management function, and the like may be implemented by one entity device, or may be implemented jointly by a plurality of entity devices, which is not specifically limited in the embodiments of the present application. That is, it may be understood that the user plane function, the access and mobility management function, the session management function, and the like in the embodiments of the present application may be one logic function module in the entity device, or may be one logic function module formed by a plurality of entity devices, or may be a function having the user plane function, the access and mobility management function, the session management function, and the like in the embodiments of the present application, which are not particularly limited.

Embodiments of the present application relate generally to two architectures. One is that the RG performs data transmission between RG and DN through connection between CPE and CPE UPF and connection between the CPE UPF and DN, as shown in fig. 3. Another is that the RG performs data transmission between RG and DN through connection between CPE and RG UPF and connection between the RG UPF and DN, as shown in fig. 4. In this application, AMF, SMF, UPF serving RG is referred to as RG AMF, RG SMF, and RG UPF for convenience of explanation; AMF, SMF, UPF serving a CPE is referred to as CPE AMF, CPE SMF, and CPE UPF. In actual use, the RG AMF and the CPE AMF may be the same entity, or the same network element, i.e. one AMF serves both the RG and the AMF. Similarly, the RG SMF and the CPE SMF, the RG UPF and the CPE UPF may be the same entity, or the same network element.

The architecture shown in fig. 3 includes AN RG, CPE (Customer-premises equipment), (R) AN, core network. Wherein (R) AN and core network are specifically described with reference to fig. 1. The CPE transmits NAS signaling between the RG and the RG AMF through a Non-Access-Stratum (NAS) connection between the CPE and the CPE AMF. Uplink and downlink Data exchanged between the RG and a Data Network (DN) are transmitted through a connection from the CPE to the DN, that is, uplink and downlink Data transmission of the RG is carried through a connection established between the CPE, the RAN and the CPE UPF. In contrast to the architecture of fig. 2, in the architecture of fig. 3, there is no need to establish an IPSec tunnel between N3GF and RG, and uplink and downlink data transmission between RG and DN is performed through N3GF and RG UPF.

The architecture shown in fig. 4 includes AN RG, CPE (Customer-premises equipment), (R) AN, core network. Wherein (R) AN and core network are specifically referred to in the description of fig. 1. The CPE transmits NAS signaling between the RG and the RG AMF through a NAS connection between the CPE and the CPE AMF. The transmission of uplink and downlink data between the RG and the DN is performed through a connection between the CPE and the RG UPF and a connection between the RG UPF and the DN. In contrast to the architecture of fig. 2, in the architecture of fig. 4, there is no need to establish an IPSec tunnel between N3GF and RG, and uplink and downlink data transmission between RG and DN is performed through N3 GF.

As an embodiment, the connections described in fig. 3 and 4 above, such as the connection between CPE and CPE UPF, the connection between CEP and RG UPF, may be established using a PDU session establishment procedure.

Note that, the RG and CPE in fig. 3 and 4 have UE functions. Therefore, in practical deployment, the RG and CPE in the architecture of fig. 2 can be replaced by other terminal devices with UE functions. For example, the RG may be a UE or a CPE, and the CPE may be a UE or an RG. In other words, the architecture shown in fig. 2 may describe that one UE accesses the 5G core network through another UE, or that one UE accesses the 5G core network through one RG or CPE, or that one RG accesses the 5G core network through another RG or CPE, etc.

A method for establishing a connection according to an embodiment of the present application is described below with reference to the architecture shown in fig. 3. As shown in fig. 5, the method includes:

s501: the RG sends a first RG NAS message to the CPE.

Wherein the first RG NAS message is used for requesting to establish the RG PDU session.

In this application, NAS messages passed between CPE and CPE AMF are referred to as CPE NAS messages; NAS messages transferred between RG and RG AMF are called RG NAS messages; the PDU session of the RG is called an RG PDU session, and the PDU session of the CPE is called a CPE PDU session.

The first RG NAS message includes a first RG PDU session establishment request parameter.

Illustratively, the RG NAS message includes an RG session management container (SM container) in which the first RG PDU session establishment request parameter is included.

The first RG PDU session establishment request parameter describes characteristics of a PDU session that the RG requests to be established. Illustratively, the first PDU session establishment parameter includes a PDU session identification (PDU session ID). Optionally, the first PDU session establishment parameter may further include: data network name (Data Network Name, DNN), network slice selection assistance information (Network Slice Selection Assistance Information, NSSAI), session and service continuity mode (Session and Service Continuity Mode, SSC mode), or PDU session Type, etc. Wherein the PDU session ID is an identification allocated by the RG for requesting the establishment of the PDU session; DNN is the name of DN to which the RG requests a connection; NSSAI is slice information corresponding to DN of RG request connection; the SSC mode is a session and service continuity mode of a PDU session that the RG requests to be established; the PDU session Type refers to the Type of PDU session that the RG requests to establish. For example, the type of the PDU session may be an IPv4 type, an IPv6 type, an IPv4v6 type, an Ethernet type, or an Unstructured type.

As an alternative embodiment, the first RG NAS message may be carried on a PPPoE connection between an RG and a CPE.

As an alternative embodiment, the RG sends a first message to the CPE, the first message including the first RG NAS message. The first message may be a vendor specific message (Vender Specific Message, VSM). Optionally, the first message further includes a second RG PDU session establishment request parameter. The second RG PDU session establishment request parameter may include some or all of the first RG PDU session establishment request parameter. Through the second RG PDU session establishment request parameter, the CPE can learn that the RG requests to establish a PDU session. Optionally, the CPE may also learn the characteristics of the PDU session that the RG requests to be established.

S502: the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS message to the RG AMF so as to acquire a first response of the network to the request of establishing the RG PDU session.

The first response is used to indicate that the network accepts the request to establish the RG PDU session. It will be appreciated that the first response may be considered by the network as an authorization to establish an RG PDU session, i.e. to indicate that the RG is allowed to establish the RG PDU session in the network. Alternatively, the CPE may obtain the network-determined RG PDU session establishment parameter from the network upon obtaining the first response. The network-determined RG PDU session establishment parameters include the IP address of the RG assigned for the RG PDU session. Optionally, the network-determined RG PDU Session establishment parameter further includes PDU Session ID, DNN, nsai, SSC mode, or PDU Session Type. The network-determined RG PDU session establishment parameter may be different from the first RG PDU session establishment request parameter. The first response may be an acceptance message for the first RG NAS message, for example.

S503: the CPE establishes or selects a CPE PDU session for transmitting the RG PDU session data.

Wherein the CPE PDU session is the same as the DNN or nsai of the RG PDU session described above such that the destination address of the packets of the RG PDU session is reachable for the CPE PDU session. In other words, the CPE establishes or selects a connection with the data network to which the RG requests a connection.

Scheme one: the CPE establishes a CPE PDU session.

As a possible implementation, the CPE may establish the CPE PDU session according to one or more of the RG PDU session establishment parameters determined by the network described above. For example, if the RG PDU session establishment parameter includes DNN1 and nsai 1, the CPE requests to establish a PDU session with DNN1 and nsai 1.

As another possible implementation, the CPE may establish the CPE PDU session according to one or more of the above-described second RG PDU session establishment request parameters. For example, if the second RG PDU session establishment request parameter includes DNN1 and nsai 1, the CPE requests to establish a PDU session with DNN1 and nsai 1. Alternatively, when the CPE does not acquire the network-determined RG PDU session establishment parameter, the CPE PDU session may be established using one or more of the second RG PDU session establishment request parameters.

As yet another possible implementation, the CPE may establish the CPE PDU session based on one or more of the default PDU session establishment parameters. At this time, the RG may also establish the RG PDU session according to one or more of the default PDU session establishment parameters. The default PDU session establishment parameters may be network configured or agreed upon by standard protocols. As an example, the default PDU session establishment parameter may include DNN, nsai, SSC mode, or PDU session Type. Optionally, when the CPE does not acquire the network-determined RG PDU session establishment parameter and the second RG PDU session establishment request parameter, one or more of the default PDU session establishment parameters may be used to establish the CPE PDU session.

Scheme II: the CPE selects a CPE PDU session.

The CPE may determine whether there is a CPE PDU session that satisfies the RG PDU session. If there is a CPE PDU session that satisfies the RG PDU session, then the RG can be serviced through the CPE PDU session.

In one possible implementation, the CPE may determine whether there is a CPE PDU session that satisfies the RG PDU session by whether the CPE PDU session matches one or more of the network-determined RG PDU session establishment parameters. For example: a CPE PDU session may be considered to satisfy an RG PDU session when the DNN or nsai of the CPE PDU session satisfies the DNN or nsai in the network-determined RG PDU session establishment parameters.

In another possible embodiment, the CPE may determine whether there is a CPE PDU session that satisfies the RG PDU session according to one or more of the above-described second RG PDU session establishment request parameters. For example, the second RG PDU session establishment request parameter includes DNN1, and the CPE has established a PDU session with DNN1, and then determines that the CPE PDU session is a CPE PDU session that satisfies the RG PDU session. Optionally, when the CPE does not acquire the network-determined RG PDU session establishment parameter, one or more of the second RG PDU session establishment request parameters may be used to determine a CPE PDU session that satisfies the RG PDU session.

As yet another possible implementation, the CPE may also determine whether there is a CPE PDU session that satisfies the RG PDU session based on one or more of the default PDU session establishment parameters. At this time, the RG PDU session may also be established according to one or more of the default PDU session establishment parameters. The default PDU session establishment parameters may be network configured or agreed upon by standard protocols. As an example, the default PDU session establishment parameter may include DNN, nsai, SSC mode, or PDU session Type.

In the method, the association relation between RG PDU conversation and CPE PDU conversation can be stored on the CPE, and the CPE can convert the uplink data packet of the RG PDU conversation into the uplink data packet of the CPE PDU conversation according to the association relation and send the uplink data packet to the DN through the CPE PDU conversation; correspondingly, the CPE can receive the downlink data packet of the CPE PDU session from the DN through the CPE PDU session, convert the downlink data packet of the CPE PDU session into the downlink data packet of the RG PDU session according to the association relation and send the downlink data packet to the RG.

As a first possible implementation manner of establishing the association relationship between the RG PDU session and the CPE PDU session, the association relationship between the IP address of the RG allocated for the RG PDU session and CPE PDU Session ID may be stored on the CPE, as shown in table 1. Since the RG PDU session has a one-to-one correspondence with the IP address allocated for the RG PDU session, the corresponding RG PDU session can be identified by the RG IP address.

RG IP address 1	CPE PDU Session ID 1
		RG IP address 2	CPE PDU Session ID 2

TABLE 1

In this possible implementation manner, when the CPE receives an uplink packet of an RG, the CPE determines a corresponding CPE PDU session according to an IP address of the RG carried by the uplink packet, and sends the uplink packet according to the CPE PDU session. When receiving a downlink data packet of a CPE PDU Session, the CPE determines the IP address of a corresponding RG through the CPE Session ID corresponding to the downlink data packet, and sends the downlink data packet to the RG through the RG IP address.

As a second possible implementation manner of the above association relationship, if a PDU Session granularity of 5WE (5G Wireless Wireline Convergence User Plane Encapsulation) Session is established between the RG and the CPE, and the 5WE Session and the RG PDU Session are in a one-to-one correspondence relationship, the association relationship between the 5WE Session ID and CPE PDU Session ID may be stored on the CPE, as shown in table 2. The corresponding RG PDU Session can be identified by the 5WE Session ID.

5WE Session ID 1	CPE PDU Session ID 1
		5WE Session ID 2	CPE PDU Session ID 2

TABLE 2

In this possible implementation manner, when the CPE receives an uplink packet of the RG, the CPE determines a corresponding CPE PDU Session according to the 5WE Session ID carried in the uplink packet, and sends the uplink data according to the CPE PDU Session. When receiving the downlink data of the RG, the CPE determines a corresponding 5WE Session ID through the CPE Session ID corresponding to the downlink data, and sends the downlink data through a channel corresponding to the 5WE Session ID.

As a third possible implementation manner of establishing the above association relationship, on the basis of the second possible manner, if different RG PDU sessions of the same RG may share the same CPE PDU session, or RG PDU sessions of different RG may share the same CPE PDU session, it may be considered to introduce a CPE port number to distinguish different RG PDU sessions. Wherein, because the 5WE session identifier is allocated by the CPE, the CPE can allocate different 5WE session identifiers for different 5WE sessions. As shown in table 3.

TABLE 3 Table 3

In this possible implementation manner, when the CPE receives the uplink data of the RG, the CPE determines a corresponding CPE PDU Session and a CPE port number according to the 5WE Session ID carried in the uplink data packet, and sends the uplink data according to the CPE PDU Session and the CPE port number. When the CPE receives downlink data of the RG, the CPE determines a corresponding 5WE Session ID through the PDU Session ID corresponding to the downlink data and the CPE port number, and sends the downlink data through a channel corresponding to the 5WE Session ID.

Optionally, in the above three possible embodiments, before the CPE sends the uplink data, the source IP address carried in the uplink data may be replaced with the IP address of the corresponding CPE PDU session; correspondingly, before sending the downlink data, the CPE replaces the destination IP address carried in the downlink data with the IP address of the corresponding RG.

Through the steps S501-S503, NAS signaling between the RG and the RG AMF is transferred through NAS connection between the CPE and the CPE AMF, and uplink and downlink data of the RG and the DN are transmitted through connection between the CPE and the DN, so that a multi-layer IPSec tunnel is not required to be established, implementation complexity of the RG and the CPE is simplified, a detour path for signaling and data transmission is reduced, and communication delay is reduced.

As an alternative implementation manner of S502, the method in which the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS to the RG AMF to obtain the first response of the network to the request for establishing the RG PDU session may refer to fig. 6. As shown in fig. 6, S502 includes:

s601: the CPE sends a first CPE NAS message to the CPE AMF.

Wherein the first CPE NAS message includes the first RG NAS message of the RG received in S501. As an alternative implementation, the first CPE NAS message may include a first RG NAS message and a first RG identification. The first RG identification is an identification that uniquely identifies the RG in the CPE. The first RG identification may be an identification allocated by the CPE to the RG, or an identification of a connection between the CPE and the RG (e.g. PPPoE connection ID), or a MAC address of the RG, or an identification allocated by the network to the RG. The first RG identification can learn that the first RG NAS message is an RG NAS message of an RG identified by the first RG identification. Optionally, a container may be included in the first CPE NAS message, where the container is configured to carry the first RG NAS message and the first RG identification.

S602: the CPE AMF sends a first RG NAS message of an RG to the RG AMF.

After receiving the first CPE NAS message, the CPE AMF may obtain the first RG NAS message of the RG from the first CPE NAS message, and forward the first RG NAS message to the RG AMF.

Alternatively, the CPE AMF may send a first message to the RG AMF, the first message comprising a first RG NAS message of the RG. As an alternative embodiment, the first message includes a first RG NAS message and a first RG identification. The first RG NAS message can be known to be the RG NAS message of the RG identified by the first RG identification through the first RG identification. The first message may be, for example, an interface message between AMFs.

Alternatively, the CPE AMF may select the RG AMF according to a local configuration or AMF selection information provided by the CPE. The AMF selection information may include a location where the RG is located (e.g., tracking area, service area, geographic location, etc.), a slice where the RG requests access, or the like. The AMF selection information may be generated by the CPE or may be transmitted to the CPE by the RG.

S603: the RG AMF sends a session establishment request message to the RG SMF according to the received first RG NAS message.

Wherein the session establishment request message is used for requesting to establish an RG PDU session of the RG.

Optionally, the session establishment request message includes a first RG PDU session establishment request parameter. The description of the first RG PDU session establishment request parameter can be referred to as step S501. Optionally, the session establishment request message further includes a second RG identification. The second RG identifier can know that the request is to establish an RG PDU session of the RG identified by the second RG identifier. The second RG identity may be an identity used by the RG in the 5G core network, such as a subscriber permanent identity (Subscription Permanent Identifier, SUPI) or an international mobile subscriber identity (International Mobile Subscription Identity, IMSI). Alternatively, the first RG identification may be the same as the second RG identification. Optionally, the first RG identifier may be different from the second RG identifier, and the RG AMF may convert the first RG identifier into the second RG identifier after receiving the first RG identifier. Alternatively, the mapping relationship between the first RG identification and the second RG identification may be obtained during registration of the RG to the network through the CPE.

S604: the RG SMF acquires subscription data of the RG from the UDM.

As a possible implementation manner, the RG SMF determines that the first RG PDU session establishment request parameter is consistent with subscription data of the RG. Illustratively, if the first RG PDU session establishment request parameter includes DNN1, and the subscription data of the RG allows the RG to access DNN1, the first RG PDU session establishment request parameter is consistent with the subscription data of the RG.

S604 is optional.

S605: the RG SMF transmits a session setup response message to the RG AMF.

The session establishment response message is used to indicate acceptance of the RG PDU session to establish the RG.

Optionally, the session establishment response message includes RG PDU session establishment parameters determined by the network. Illustratively, the network-determined RG PDU session establishment parameters include the IP address of the RG assigned for the RG PDU session. Optionally, the network-determined RG PDU Session establishment parameters also include PDU Session ID, SSC mode, S-NSSAI (S), DNN, session-AMBR, or PDU Session Type, etc. Optionally, the session establishment response message further includes a second RG identification. The second RG identifier can know that the RG PDU session accepted to be established is the RG PDU session of the RG identified by the second RG identifier. In the embodiment of the present application, the RG PDU session establishment parameter determined by the network may also be understood as an RG PDU session establishment parameter determined by the core network.

S606: the RG AMF sends a second RG NAS message to the CPE AMF addressed to the RG. Wherein the second RG NAS message is used for informing that the RG PDU session of the RG is accepted to be established.

Alternatively, the RG AMF may send a second message to the CPE AMF, the second message comprising a second RG NAS message of the RG. As an alternative embodiment, the second message includes a second RG NAS message and a first RG identification. The first RG identifier can acquire that the second RG NAS message is an RG NAS message sent to an RG identified by the first RG identifier. Alternatively, the second message may be an interface message between AMFs. Optionally, the second message further includes RG PDU session establishment parameters determined by the network.

Alternatively, the RG AMF may determine the first RG identification according to the second RG identification.

S607: the CPE AMF sends a second CPE NAS message to the CPE.

Wherein the second CPE NAS message includes the second RG NAS message addressed to the RG. Optionally, the second CPE NAS message further includes a first RG identification. The first RG identifier can know that the second RG NAS message is an RG NAS message sent to an RG identified by the first RG identifier. Optionally, the second CPE NAS message further includes an RG PDU session establishment parameter determined by the network.

S608: the CPE sends a second RG NAS message to the RG.

Through the steps S601-S608, the CPE transmits the RG NAS signaling between the RG and the RG AMF through the CPE NAS message interaction with the CPE AMF and the message interaction between the CPE AMF and the RG AMF, thereby shortening the transmission delay of the control plane signaling.

In the above process, the CPE may acquire the network response to the RG NAS message. The response includes a response by the network to the RG request to establish the PDU session. The CPE can establish or select a CPE PDU session for transmitting the data of the RG PDU session based on the response, thereby shortening a data transmission path and reducing a transmission delay of user plane data.

As an alternative embodiment of S503, a method for the CPE to establish a CPE PDU session for transmitting the RG PDU session data may refer to fig. 7. As shown in fig. 7, S503 includes:

s701: the CPE sends a third CPE NAS message to the CPE AMF requesting to establish the CPE PDU session.

Optionally, the third CPE NAS message may include a first CPE PDU session establishment parameter. Optionally, the third CPE NAS message may further include CPE PDU session ID.

Optionally, the first CPE PDU session establishment parameter may include one or more of the RG PDU session establishment parameters determined by the network in S502.

Optionally, the first CPE PDU session establishment parameter may include one or more of the second RG PDU session establishment request parameters. Alternatively, when the CPE does not acquire the network-determined RG PDU session establishment parameter, the CPE PDU session may be established using one or more of the second RG PDU session establishment request parameters.

Optionally, the first CPE PDU session establishment parameter may include one or more of the default PDU session establishment parameters. Optionally, when the CPE does not acquire the network-determined RG PDU session establishment parameter and the second RG PDU session establishment request parameter, one or more of the default PDU session establishment parameters may be used to establish the CPE PDU session.

As an understanding, the first CPE PDU session establishment parameter is chosen to make the CPE PDU session the same as the DNN or nsai of the RG PDU session.

CPE PDU session ID may be assigned by the CPE for that CPE PDU session.

S702: the CPE AMF sends a session establishment request message to the CPE SMF.

The session establishment request message includes a first CPE PDU session establishment parameter.

S703: an N4 session is established between the CPE SMF and the CPE UPF.

S704: the CPE SMF sends a session establishment response message to the CPE AMF.

The session establishment response message includes the IP address of the CPE assigned by the CPE SMF for the CPE PDU session.

S705: the CPE AMF sends a fourth CPE NAS message to the CPE.

The fourth CPE NAS message includes the IP address of the CPE allocated by the CPE SMF for the CPE PDU session.

Through the steps S701-S705 described above, the CPE establishes a CPE PDU session identical to the DNN or nsai of the RG PDU session according to the response of the network to the RG PDU session requested to be established by the first RG NAS message. The data of the RG PDU session can be transmitted through the CPE PDU session, so that uplink and downlink data of the RG and the DN are transmitted through the connection of the CPE and the DN, a multi-layer IPSec tunnel is not required to be established, the implementation complexity of the RG and the CPE is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

In the method of fig. 5, the CPE PDU session is performed after the setup of the RG PDU session is accepted by the network. As a variation of the method of fig. 5, the establishment of the CPE PDU session may be initiated before the establishment of the RG PDU session is accepted by the network. Another method for establishing a connection according to the embodiment of the present application is described below with reference to the architecture shown in fig. 3.

As shown in fig. 8, the method includes:

s801: the RG sends a first RG NAS message to the CPE.

S801 can be seen in S501.

Alternatively, the second RG PDU session establishment request parameter as described in S501 may be obtained in S801.

S802: the CPE establishes or selects a CPE PDU session for transmitting the RG PDU session data.

Scheme one: the CPE establishes a CPE PDU session.

Scheme one can be seen in particular in S503. It should be noted that, since the establishment of the CPE PDU session is initiated before the establishment of the RG PDU session is accepted by the network, the CPE has not acquired the RG PDU session establishment parameters determined by the network at S802.

Optionally, after the CPE acquires the second RG PDU session establishment request parameter in S801, the CPE PDU session may be established according to one or more parameters of the second RG PDU session establishment request parameter.

Optionally, the RG PDU session may be established according to one or more of default PDU session establishment parameters, and the CPE may also establish the RG PDU session according to one or more of the default PDU session establishment parameters.

Scheme II: the CPE selects a CPE PDU session.

Scheme two may refer to S503 specifically.

S803: the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS message to the RG AMF so as to acquire a first response of the network to the request of establishing the RG PDU session.

S803 can be seen in particular from S502.

In the method, the association relationship between the RG PDU session and the CPE PDU session can be stored on the CPE, and the CPE can convert the uplink data packet of the RG PDU session into the uplink data packet of the CPE PDU session according to the association relationship and send the uplink data packet to the DN through the CPE PDU session. Correspondingly, the CPE can receive the downlink data packet of the CPE PDU session from the DN through the CPE PDU session, convert the downlink data packet of the CPE PDU session into the downlink data packet of the RG PDU session according to the association relation and send the downlink data packet to the RG. See in particular the relevant content of the method of fig. 5.

Through the steps S801-S803, NAS signaling between the RG and the RG AMF is transferred through NAS connection between the CPE and the CPE AMF, and uplink and downlink data of the RG and the DN are transmitted through connection between the CPE and the DN, so that a multi-layer IPSec tunnel is not required to be established, implementation complexity of the RG and the CPE is simplified, a detour path for signaling and data transmission is reduced, and communication delay is reduced.

As an alternative embodiment of S802, a method for the CPE to establish a CPE PDU session for transmitting the RG PDU session data may refer to the method of fig. 9. As shown in fig. 9. S802 includes:

s901: the CPE sends a third CPE NAS message to the CPE AMF requesting to establish the CPE PDU session.

S901 can be seen in S701.

Optionally, the first CPE PDU session establishment parameter may include one or more of the second RG PDU session establishment request parameter, or one or more of the default PDU session establishment parameters. The first CPE PDU session establishment parameter is selected to make the CPE PDU session the same as the DNN or nsai of the RG PDU session.

S902: the CPE AMF sends a session establishment request message to the CPE SMF.

See S702.

S903: an N4 session is established between the CPE SMF and the CPE UPF.

See S703.

S904: the CPE SMF sends a session establishment response message to the CPE AMF.

See S704.

S905: the CPE AMF sends a fourth CPE NAS message to the CPE.

See S705.

Through the above steps S901-S905, the CPE establishes an RG PDU session according to the RG request, and establishes the same CPE PDU session as the DNN or nsai of the RG PDU session. The data of the RG PDU session can be transmitted through the CPE PDU session, so that uplink and downlink data of the RG and the DN are transmitted through the connection of the CPE and the DN, a multi-layer IPSec tunnel is not required to be established, the implementation complexity of the RG and the CPE is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

As an alternative implementation of S803, the method of the CPE sending the first RG NAS message to the CPE AMF through the CPE NAS message and forwarding the first RG NAS to the RG AMF by the CPE AMF to obtain the first response of the network to the request for establishing the RG PDU session may refer to the method of fig. 6. By the method, the CPE transmits the RG NAS signaling between the RG and the RG AMF through CPE NAS message interaction between the CPE and the CPE AMF and message interaction between the CPE AMF and the RG AMF, thereby shortening the transmission delay of the control plane signaling.

Another method for establishing a connection according to the embodiment of the present application is described below with reference to the architecture shown in fig. 4.

As shown in fig. 10, the method includes:

s1001: the RG sends a first RG NAS message to the CPE.

S1001 may be referred to S501.

S1002: the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS message to the RG AMF so as to acquire a first response of the network to the request of establishing the RG PDU session.

S1002 may refer to S502.

It should be noted that, the RG SMF needs to select an RG UPF for the RG PDU, and may notify the RG AMF of an uplink tunnel endpoint identifier of the RG UPF, and the RG AMF sends the uplink tunnel endpoint identifier to the CPE AMF. The upstream tunnel endpoint identification identifies the tunnel endpoint on the RG UPF side of the user plane connection between the RG UPF and CPE UPF in fig. 4.

S1003: the CPE establishes or selects a CPE PDU session for transmitting the RG PDU session data.

S1003 may refer to S503.

In an embodiment in which the CPE establishes a CPE PDU session for transmitting the RG PDU session data, the DNN or nsai of the CPE PDU session is the same as the DNN or nsai to which the RG UPF belongs, so that packets of the RG PDU session can be transmitted to the RG UPF through the CPE PDU session and the CPE can receive packets of the RG PDU session from the RG UPF.

In the embodiment that the CPE selects the CPE PDU session for transmitting the RG PDU session data, when the CPE determines whether there is a CPE PDU session satisfying the RG PDU session, the CPE may determine whether the DNN or nsai of the CPE PDU session is the same as the DNN or nsai to which the RG UPF belongs. If the DNN or NSSAI of the CPE PDU session is the same as the DNN or NSSAI of the RG UPF, the CPE PDU session is considered to meet the RG PDU session.

S1004: the CPE AMF establishes a user plane connection between the CPE UPF and the RG UPF.

After the CPE AMF obtains the uplink tunnel endpoint identifier of the RG UPF, the uplink tunnel endpoint identifier of the RG UPF may be sent to the CPE SMF, and the CPE SMF may send the uplink tunnel endpoint identifier of the RG UPF to the CPE UPF, so that the CPE UPF may send data (which may be regarded as uplink data) of the RG PDU session to the RG UPF according to the uplink tunnel endpoint identifier of the RG UPF. Optionally, the CPE AMF may transmit the uplink tunnel endpoint identifier of the RG UPF to the CPE UPF by using the procedure of establishing the CPE PDU session in S1003.

In addition, the CPE AMF may obtain the downstream tunnel endpoint identification of the CPE UPF from the CPE SMF, for example, the downstream tunnel endpoint identification of the CPE UPF is obtained in S1003. The downstream tunnel endpoint identification is used to identify the tunnel endpoint on the CPE UPF side of the user plane connection between the RG UPF and the CPE UPF in fig. 4. The CPE AMF sends the downlink tunnel endpoint identification to the RG AMF, the RG AMF to the RG SMF and the RG SMF to the RG UPF. By the downlink tunnel endpoint identification, the RG UPF can be enabled to send data (which can be regarded as downlink data) of the RG PDU session to the CPE UPF.

By informing the uplink tunnel endpoint identity of the RG UPF to the CPE UPF and informing the downlink tunnel endpoint identity of the CPE UPF to the RG UPF, a user plane connection between the CPE UPF and the RG UPF can be established.

In the method, the association relation between the RG PDU session and the CPE PDU session can be stored on the CPE, and the CPE can send the uplink data packet of the RG PDU session to the RG UPF through the CPE PDU session and send the uplink data packet to the destination address through the RG UPF according to the association relation. Accordingly, the CPE may transmit the downstream data packets of the CPE PDU session to the RG. See in particular the description of the method of fig. 5.

Through the steps S1001-S1004, NAS signaling between the RG and the RG AMF is transferred through NAS connection between the CPE and the CPE AMF, uplink and downlink data between the RG and the DN are transmitted through connection between the CPE and the RG UPF and connection between the RG UPF and the DN, a multi-layer IPSec tunnel is not required to be established, implementation complexity of the RG and the CPE is simplified, a detour path for signaling and data transmission is reduced, and communication delay is reduced.

The method in which the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message and the CPE AMF forwards the first RG NAS to the RG AMF to obtain the first response of the network to the request for establishing the RG PDU session can refer to fig. 11. As shown in fig. 11, S1002 includes:

S1101: the CPE sends a first CPE NAS message to the CPE AMF.

S1101 can be seen in S601.

S1102: the CPE AMF sends a first RG NAS message of an RG to the RG AMF.

S1102 can be seen in S1102.

S1103: the RG AMF sends a session establishment request message to the RG SMF according to the received first RG NAS message.

S1103 can be seen in S603.

S1104: the RG SMF acquires subscription data of the RG from the UDM.

S1104 is optional and can be seen in particular in S604.

S1105: an N4 session is established between RG SMF and RG UPF.

As a possible implementation manner, S1105 includes:

the RG SMF sends an N4 session establishment request message to the RG UPF;

the RG UPF transmits an N4 session setup response message to the RG SMF.

The N4 session establishment response message includes core network tunnel information (CN tunnel info) of the RG UPF. The CN tunnel info of the RG UPF identifies the tunnel endpoint on the RG UPF side of the user plane connection between the RG UPF and the CPE UPF in fig. 4. The tunnel endpoint is configured to receive uplink data sent by the CPE UPF, that is, a data packet sent by the CPE UPF to the RG UPF through the tunnel needs to carry information of CN tunnel info of the RG UPF. For example, the CN tunnel info of the RG UPF includes the IP address and GTP endpoint identification of the RG UPF, and the packet sent by the CPE UPF to the RG UPF through the tunnel carries the IP address and GTP endpoint identification of the RG UPF.

S1106: the RG SMF transmits a session setup response message to the RG AMF.

S1106 can be seen in S605.

Optionally, the session establishment response message further includes CN tunnel info of RG UPF.

S1107: the RG AMF sends a second RG NAS message to the CPE AMF addressed to the RG.

Optionally, in S1107, the RG AMF also transmits CN tunnel info of the RG UPF to the CPE AMF.

The RG AMF sends a second RG NAS message addressed to the RG to the CPE AMF see S606. Wherein the second CPE NAS message including the second RG NAS message addressed to the RG further includes a CN tunnel info of the RG UPF.

S1108: the CPE AMF sends a second CPE NAS message to the CPE.

S1108 can be seen in S607.

S1109: the CPE sends a second RG NAS message to the RG.

S1109 can be seen in S608.

Through the steps S1101-S1109, the CPE transmits the RG NAS signaling between the RG and the RG AMF through the CPE NAS message interaction with the CPE AMF and the message interaction between the CPE AMF and the RG AMF, thereby shortening the transmission delay of the control plane signaling.

In the above process, the CPE may acquire the network response to the RG NAS message. The response includes a response by the network to the RG request to establish the PDU session. The CPE may establish or select a CPE PDU session for transmitting data of the above-described RG PDU session based on the response. In the above procedure, the CPE AMF may receive the CN tunnel info of the RG UPF. The CPE AMF can transmit the CN tunnel info of the RG UPF to the CPE UPF in the process of establishing the CPE PDU session related to the RG PDU session, so that the CPE UPF can transmit uplink data to the RG UPF, thereby shortening the data transmission path and reducing the transmission delay of user plane data.

As an alternative embodiment of S1003, the CPE establishes or selects a CPE PDU session for transmitting the RG PDU session data, referring to fig. 12. As shown in fig. 12, S1003 includes:

s1201: the CPE sends a third CPE NAS message to the CPE AMF requesting to establish the CPE PDU session.

S1201 may refer to S701. Wherein, DNN of the CPE PDU session is the same as DNN of DN where RG UPF is located.

S1202: the CPE AMF sends a session establishment request message to the CPE SMF.

S1202 can be seen in S702.

Wherein, optionally, the session establishment request message further comprises CN tunnel info of RG UPF.

S1203: an N4 session is established between the CPE SMF and the CPE UPF.

As a possible implementation manner, S1203 includes: the CPE SMF sends an N4 session setup request message to the CPE UPF. Optionally, the N4 session establishment request message includes CN tunnel info of RG UPF. The CPE UPF sends an N4 session setup response message to the CPE SMF.

The N4 session establishment response message includes CN tunnel info of CPE UPF. Wherein the CN tunnel info of the CPE UPF identifies the tunnel endpoint on the CPE UPF side of the user plane connection between the RG UPF and the CPE UPF in fig. 4. The tunnel endpoint is configured to receive downlink data sent by the RG UPF, that is, a data packet sent by the RG UPF to the CPE UPF through the tunnel needs to carry information of CN tunnel info of the CPE UPF. For example, the CN tunnel info of the CPE UPF includes the IP address and GTP endpoint identification of the CPE UPF, and the packet sent by the RG UPF to the CPE UPF through the tunnel carries the IP address and GTP endpoint identification of the CPE UPF.

S1204: the CPE SMF sends a session establishment response message to the CPE AMF.

The session establishment response message includes the IP address of the CPE and the CN tunnel info of the CPE UPF, which are allocated by the CPE SMF for the CPE PDU session. The CN tunnel info of the CPE UPF may be used in S1004 to establish a user plane connection between the RG UPF and the CPE UPF.

S1205: the CPE AMF sends a fourth CPE NAS message to the CPE.

S1205 may refer to S705.

Through the steps S1201-S1205, the CPE establishes a CPE PDU session to the DN where the RG UPF is located and a connection between the CPE UPF and the RG UPF according to the response of the network to the RG PDU session requested to be established by the first RG NAS message. Through the connection between the CPE PDU session and the CPE UPF to the RG UPF, the data of the RG PDU session can be transmitted without establishing a multi-layer IPSec tunnel, thereby simplifying the realization complexity of the RG and the CPE, reducing the detour path of signaling and data transmission and reducing the communication delay.

As an alternative implementation of S1004, the CPE AMF establishes a user plane connection between the CPE UPF and the RG UPF, see fig. 13. As shown in fig. 13, S1004 includes:

s1301: the CPE AMF sends CN tunnel info of CPE UPF to RG AMF.

The CN tunnel info of the CPE UPF may be received by the CPE AMF in step S1204. The CN Tunnel Info of the CPE UPF may be carried in AN N2 session management information (N2 SM information) parameter or AN access network Tunnel information (AN Tunnel Info) parameter, for example.

S1302: the RG AMF sends CN tunnel info of CPE UPF to RG SMF.

The CN Tunnel Info of the CPE UPF may be carried in the N2 SM information parameter, or in the AN Tunnel Info parameter, for example.

S1303: the RG SMF sends the CN tunnel info of the CPE UPF to the RG UPF.

As a possible implementation manner, S1303 includes:

the RG SMF sends an N4 session modification request message to the RG UPF, wherein the message carries CN tunnel info of the CPE UPF;

the RG UPF transmits an N4 session modification response message to the RG SMF.

Through the steps S1301-S1303, the CPE AMF transmits the CN tunnel info of the CPE UPF received in step S1204 to the RG UPF, so that the RG UPF can transmit downlink data to the CPE UPF.

On the other hand, for upstream, the CPE UPF needs to acquire the CN tunnel info of the RG UPF. For example:

s1304: the RG SMF sends CN tunnel info of RG UPF to RG AMF.

S1305: the RG AMF sends CN tunnel info of RG UPF to CPE AMF.

As an alternative implementation of S1304 and S1305, the transfer of CN tunnel info of RG UPF from RG SMF to CPE AMF may be implemented through S1106 and S1107.

S1306: the CPE AMF sends CN tunnel info of RG UPF to the CPE SMF.

Illustratively, the CN Tunnel Info of the RG UPF may be carried in the N2 SM information parameter, or in the AN Tunnel Info parameter.

S1307: the CPE SMF transmits CN tunnel info of the RG UPF to the CPE UPF.

As a possible implementation of S1307, reference may be made to S1303, i.e. by an N4 session modification procedure.

As an alternative implementation of S1306 and S1307, the transfer of CN tunnel info of RG UPF from CPE AMF to RG UPF can be implemented through S1202 and S1203.

Through the steps S1304-S1307, the CN tunnel info of the RG UPF can be transferred to the CPE UPF, and the CPE UPF can be enabled to transfer uplink data to the RG UPF.

By establishing the connection between the RG UPF and the CPE UPF, the establishment of a multi-layer IPSec tunnel can be avoided, and the detour of the transmission path can be reduced.

In the method of fig. 10, the CPE PDU session is performed after the setup of the RG PDU session is accepted by the network. As a variation of the method of fig. 10, the establishment of the CPE PDU session may be initiated before the establishment of the RG PDU session is accepted by the network.

As shown in fig. 14, the method includes:

s1401: the RG sends a first message to the CPE.

S1401 can be seen in S801.

S1402: the CPE establishes or selects a CPE PDU session for transmitting the RG PDU session data.

S1402 can be seen in S802.

When the CPE establishes the CPE PDU session, the DNN of the DN where the RG UPF is located can be preconfigured and used for establishing the CPE PDU session because the establishment of the CPE PDU session is initiated before the establishment of the RG PDU session is accepted by the network, so that the connectivity from the CPE to the RG UPF is realized.

S1403: the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS message to the RG AMF so as to acquire a first response of the network to the request of establishing the RG PDU session.

S1403 can be seen in S803.

In S1403, the CPE AMF may acquire an upstream tunnel endpoint identity of the RG UPF. The upstream tunnel endpoint identification may refer to the description in step S1002.

In the above method, the association relationship between the RG PDU session requested to be established in S1401 by the first RG NAS message and the CPE PDU session determined in S1402 may be stored in the CPE, and the uplink and downlink data packets may be processed and routed according to the association relationship, which may be described in step S503.

S1404: and establishing a user plane connection between the CPE UPF and the RG UPF.

After the CPE AMF obtains the uplink tunnel endpoint identifier of the RG UPF, the uplink tunnel endpoint identifier of the RG UPF may be sent to the CPE SMF, and the CPE SMF may send the uplink tunnel endpoint identifier of the RG UPF to the CPE UPF, so that the CPE UPF may send data (which may be regarded as uplink data) of the RG PDU session to the RG UPF according to the uplink tunnel endpoint identifier of the RG UPF. Optionally, the CPE AMF may transmit the uplink tunnel endpoint identification of the RG UPF to the CPE UPF using the procedure of establishing the CPE PDU session in S1403.

In addition, the CPE AMF may obtain the downstream tunnel endpoint identification of the CPE UPF from the CPE SMF, for example, the downstream tunnel endpoint identification of the CPE UPF is obtained in S1403. The downstream tunnel endpoint identification is used to identify the tunnel endpoint on the CPE UPF side of the user plane connection between the RG UPF and the CPE UPF in fig. 4. The CPE AMF sends the downlink tunnel endpoint identification to the RG AMF, the RG AMF to the RG SMF and the RG SMF to the RG UPF. By the downlink tunnel endpoint identification, the RG UPF can be enabled to send data (which can be regarded as downlink data) of the RG PDU session to the CPE UPF.

Through the steps S1401-S1404, NAS signaling between the RG and the RG AMF is transferred through NAS connection between the CPE and the CPE AMF, uplink and downlink data between the RG and the DN are transmitted through connection between the CPE and the RG UPF and connection between the RG UPF and the DN, without establishing a multi-layer IPSec tunnel, thereby simplifying implementation complexity of the RG and the CPE, reducing a detour path for signaling and data transmission, and reducing communication delay.

The method in which the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message and the CPE AMF forwards the first RG NAS to the RG AMF to obtain the first response of the network to the request for establishing the RG PDU session can refer to fig. 15. As shown in fig. 15, S1402 includes:

S1501: the CPE sends a first CPE NAS message to the CPE AMF.

S1501 can be seen in S901.

S1502: the CPE AMF sends a session establishment request message to the CPE SMF.

S1502 may be seen in S902.

S1503: an N4 session is established between the CPE SMF and the CPE UPF.

As a possible implementation manner, S1503 includes:

the CPE SMF sends an N4 session establishment request message to the CPE UPF;

the CPE UPF sends an N4 session setup response message to the CPE SMF.

Optionally, the N4 session establishment response message includes CN tunnel info of CPE UPF. The explanation of CN tunnel info of CPE UPF is referred to step S1203.

S1504: the CPE SMF sends a session establishment response message to the CPE AMF.

Optionally, the session establishment response message includes an IP address allocated by the CPE SMF for the CPE PDU session and a CN tunnel info of the CPE UPF.

S1505: the CPE AMF sends a second CPE NAS message to the CPE.

S1505 can be seen in S905.

Through the above steps S1501 to S1505, the CPE establishes a CPE PDU session identical to the DNN or nsai of the RG PDU session. The data of the RG PDU session can be transmitted through the CPE PDU session, so that uplink and downlink data of the RG and the DN are transmitted through the connection of the CPE and the DN, a multi-layer IPSec tunnel is not required to be established, the implementation complexity of the RG and the CPE is simplified, the detour path of signaling and data transmission is reduced, and the communication time delay is reduced.

As an alternative implementation of S1403, the CPE sends the first RG NAS message to the CPE AMF through the CPE NAS message, and the CPE AMF forwards the first RG NAS message to the RG AMF to obtain the first response of the network to the request for establishing the RG PDU session may refer to fig. 11.

Through CPE NAS information interaction with CPE AMF and information interaction between CPE AMF and RG AMF, the CPE transmits RG NAS signaling between RG and RG AMF, thereby shortening transmission delay of control plane signaling. In the above procedure, the CPE AMF may receive the CN tunnel info of the RG UPF. The CPE AMF may transmit the CN tunnel info of the RG UPF to the CPE UPF in the process of establishing the user plane connection between the CPE PDU session and the RG PDU session, so that the CPE UPF may transmit uplink data to the RG UPF. In the above process, the CPE may acquire the network response to the RG NAS message. The response includes a response by the network to the RG request to establish the PDU session. The only difference is that after acquiring the RG PDU session establishment parameters determined by the network, the CPE does not establish the CPE PDU session associated with the RG PDU session based on one or more parameters of the RG PDU session establishment parameters determined by the network. The CPE uses the CPE PDU session determined in step S1402 to transmit the data of the RG PDU session, thereby shortening the data transmission path and reducing the transmission delay of the user plane data.

As an alternative embodiment of S1404, a user plane connection between the CPEUPF and the RG UPF is established, see fig. 16. As shown in fig. 16, includes:

s1601: the CPE AMF sends CN tunnel info of CPE UPF to RG AMF.

The CN tunnel info of the CPE UPF is received by the CPE AMF in step S1504. The parameters of CN tunnel info carrying CPE UPF are described in step S1301.

S1602: the RG AMF sends CN tunnel info of CPE UPF to RG SMF.

This step can be described with reference to step S1302. S1603 the RG SMF sends CN tunnel info of CPE UPF to the RG UPF.

This step may refer to the description of step S1303.

S1604, CPE AMF sends CN tunnel info of RG UPF to CPE SMF.

The CN tunnel info of the RG UPF is received by the CPE AMF in step S1106. Illustratively, the CPE AMF sends a session establishment request message to the CPE SMF. The session establishment request message includes CN tunnel info of RG UPF.

S1605, the CPE SMF transmits CN tunnel info of RG UPF to CPE UPF.

As a possible implementation manner, step S1605 includes:

the CPE SMF sends an N4 session modification request message to the CPE UPF.

The N4 session modification request message carries CN tunnel info of RG UPF;

the CPE UPF sends an N4 session modification response message to the CPE SMF.

Through the above steps S1601-S1605, the CPE AMF transmits the CN tunnel info of the CPE UPF received in step S1504 to the RG UPF, so that the RG UPF can transmit downstream data to the CPE UPF. The CPE AMF transfers the CN tunnel info of the RG UPF received in step S1106 to the CPE UPF so that the CPE UPF can transfer upstream data to the RG UPF. Thus, user plane connection establishment between the CPE PDU session and the RG PDU session is completed.

It should be noted that, there is no precedence between the execution of steps S1601-S1603 and steps S1604-S1605. The CPE AMF may perform steps S1601-S1603 first, may perform steps S1604-S1605 first, or may perform steps S1601-S1603 and steps S1604-S1605 simultaneously. On the other hand, for upstream, the CPE UPF needs to acquire the CN tunnel info of the RG UPF. Reference is made to the description of S1304-S1307.

Through the steps, the CN tunnel info of the RG UPF can be transmitted to the CPE UPF, and the CPE UPF can be enabled to transmit uplink data to the RG UPF.

The method shown in fig. 5 to 9 will be described below from the CPE side. As shown in fig. 17, the method includes:

S1701: the first terminal device receives a first message of a second terminal requesting to establish a first connection of the second terminal device with a data network.

Wherein the first terminal device may be the CPE of fig. 5-9; the second terminal device may be the RG of fig. 5 to 9; the first message may be a first RG NAS message; the first connection may be a PDU session of the RG.

S1701 may refer to the description of S501 or S801.

S1702: the first terminal equipment forwards the first message to the core network through a control plane between the first terminal equipment and the core network so as to acquire a response of the core network accepting the request for establishing the first connection.

The control plane between the first terminal device and the core network may be NAS messages between the CPE and the CPE AMF.

S1702 may refer to S502 or the description of fig. 6 or S803.

S1703: the first terminal device establishes or selects a second connection for transmitting data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

Wherein the second connection may be a PDU session of the CPE.

In one possible embodiment, the first terminal device performs S1702 and then S1703. In this possible embodiment, S1703 may refer to S503 or the description of fig. 7.

In another possible embodiment, the first terminal device performs S1703 first and then S1702. In this possible implementation, S1703 may refer to S802 or the description of fig. 9.

Through the above steps 1701-1703, the first terminal device forwards the first message of the second terminal device to the core network through the control plane between the first terminal device and the core network, and the first terminal device establishes or selects the second connection of the first terminal device for transmitting the data of the first connection of the second terminal device, without establishing a multi-layer IPSec tunnel, thereby simplifying the implementation complexity of the first terminal device and the second terminal device, reducing the detouring path of the transmission of signaling and data, and reducing the communication delay.

The method shown in fig. 5 to 9 will be described below from the RG side. As shown in fig. 18, the method includes:

s1801: the second terminal device sends a first message to the first terminal device requesting to establish a first connection of the second terminal device with the data network.

S1801 may refer to the description of S501 or S801.

S1802: the second terminal equipment receives a response of the core network acceptance request sent by the first terminal equipment for establishing the first connection.

S1802 may refer to the description of S608.

Through the above S1801-S1802, the second terminal device requests to establish the first connection to the core network through the first terminal device, and receives, through the first terminal device, a response of the core network to the first connection establishment request, without establishing a multi-layer IPSec tunnel, thereby simplifying implementation complexity of the first terminal device and the second terminal device, reducing a detour path of signaling transmission, and reducing communication delay.

The method shown in fig. 5 to 16 will be described below from the RG AMF side. As shown in fig. 19, the method includes:

s1901: the first control plane network element obtains a first message of the second terminal device through a second control plane network element of the first terminal device, and the first message requests to establish a first connection between the second terminal device and the data network.

Wherein, the first control plane network element may be an RG AMF in fig. 5 to 16; the first terminal device may be the CPE of fig. 5-16; the second control plane network element may be a CPE AMF of fig. 5-16; the second terminal device may be the RG of fig. 5 to 16; the first message may be a first RG NAS message; the first connection may be a PDU session of the RG.

S1901 may refer to the description of S602 or S1102.

S1902: the first control plane network element sends the first message to a third control plane network element serving the second terminal device to obtain a response of the core network to the reception request to establish the first connection.

Wherein the third control plane network element may be an RG SMF of fig. 5-16.

S1902 may refer to the description of S603 or S1103.

Through the above-mentioned S1901-S1902, the first control plane network element obtains, through the control plane with the first terminal device, the first message of the second terminal device, and obtains the response of the core network to the reception request to establish the first connection, and supports the establishment of the first connection establishment request of the second terminal device. The above process does not need to establish a multi-layer IPSec tunnel, simplifies the implementation complexity of the first terminal device and the second terminal device, reduces the detour path of signaling transmission, and reduces the communication time delay.

Fig. 20 is a schematic block diagram of a communication device 2000 provided for an embodiment of the present application. The communication device 2000 is, for example, a first terminal device.

The first terminal device comprises a processing module 2010. Optionally, a transceiver module 2020 may also be included. The first terminal device 2000 may be a terminal device, a chip applied in a terminal device, or other combination devices, components, etc. having the functions of the first terminal device. When the first terminal device 2000 is a terminal device, the transceiver module 2020 may be a transceiver, which may include wired or wireless devices, etc., including an antenna, a radio frequency module, a wired connection line, etc., and the processing module 2010 may be a processor (or processing circuit), such as a baseband processor, which may include one or more CPUs. When the first terminal device 2000 is a component having the above-described first terminal device function, the transceiver module 2020 may be a radio frequency unit, and the processing module 2010 may be a processor (or processing circuit), for example, a baseband processor. When the first terminal device 2000 is a chip system, the transceiver module 2020 may be an input/output interface of a chip (e.g., a baseband chip), and the processing module 2010 may be a processor (or processing circuit) of the chip system, and may include one or more central processing units. It is to be appreciated that processing module 2010 in embodiments of the present application may be implemented by a processor or processor-related circuit component (alternatively referred to as a processing circuit), and that transceiver module 2020 may be implemented by a transceiver or transceiver-related circuit component.

For example, the processing module 2010 may be configured to perform all operations performed by the first terminal device in the embodiment shown in fig. 17, except for the transceiving operations, e.g., S1703, and/or other procedures for supporting the techniques described herein. The transceiving module 2020 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 17, e.g., S1701 and S1702, and/or other procedures for supporting the techniques described herein.

The communication device 2000 is, for example, a second terminal device. The second terminal device comprises a processing module and a transceiver module, and reference may be made to the description of the first terminal device. For example, the transceiving module 2020 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 18, e.g., S1801 and S1802, and/or other procedures for supporting the techniques described herein.

The communication device 2000 is illustratively a first control plane network element. The first control plane network element 2000 includes a processing module 2010. Optionally, a transceiver module 2020 may also be included. For example, the transceiving module 2020 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 19, e.g., S1901 and S1902, and/or other procedures for supporting the techniques described herein.

The method shown in fig. 10 to 16 will be described below from the CPE side. As shown in fig. 21, the method includes:

s2101: the first terminal device receives a first message of a second terminal, the first message requesting to establish a first connection of the second terminal device with a data network.

Wherein the first terminal device may be the CPE of fig. 10-16; the second terminal device may be the RG of fig. 10 to 16; the first message may be a first RG NAS message; the first connection may be a PDU session of the RG.

S2101 may refer to the description of S1001 or S1401.

S2102: the first terminal device forwards the first message to the core network through a control plane between the first terminal device and the core network so as to establish connection between the user plane network element of the first connection and the data network.

S2102 may refer to the description of S1002 or fig. 11 or S1403.

S2103: the first terminal equipment establishes or selects a second connection for transmitting the data of the first connection, wherein the second connection is a connection of the first terminal equipment and a data network where a user plane network element of the first connection is located.

Wherein the second connection may be a PDU session of the CPE.

Wherein the connection between the user plane network element of the first connection and the user plane network element of the second connection is established by means of the establishment of the first connection and the establishment or modification of the second connection.

In one possible implementation, the first terminal device performs S2102 and then S2103. In this possible embodiment, S2103 may refer to S1003 or the description of fig. 12. The connection establishment between the user plane network element of the first connection and the user plane network element of the second connection may refer to S1004 or fig. 13.

In another possible embodiment, the first terminal device performs S2103 before S2102. In this possible embodiment, S2103 may refer to S1402 or the description of fig. 15. The connection establishment between the user plane network element of the first connection and the user plane network element of the second connection may refer to S1404 or fig. 15.

Through the above S2101-S2103, the first terminal device forwards the first message of the second terminal device to the core network through the control plane between the first terminal device and the core network, and the first terminal device establishes or selects the second connection of the first terminal device for transmitting the data of the first connection of the second terminal device, without establishing a multi-layer IPSec tunnel, thereby simplifying the implementation complexity of the first terminal device and the second terminal device, reducing the detour path of the transmission of signaling and data, and reducing the communication delay.

The method shown in fig. 10 to 16 will be described below from the RG side. As shown in fig. 18, the method may refer to the description of fig. 18.

The method shown in fig. 10 to 16 will be described below from the CPE AMF side. As shown in fig. 22, the method includes:

s2201: the first control plane network element acquires a first message of the second terminal device through a control plane of the first terminal device, wherein the first message requests to establish a first connection between the second terminal device and the data network.

Wherein, the first control plane network element may be CPE AMF in fig. 10-16; the first terminal device may be the CPE of fig. 5-9; the second terminal device may be the RG of fig. 5 to 9; the first message may be a first RG NAS message; the first connection may be a PDU session of the RG.

S2201 may refer to the description of S1101.

S2202: the first control plane network element sends the first message to a second control plane network element serving the second terminal device.

The second control plane network element may be an RG AMF in fig. 10-16.

S2202 can refer to the description of S1102.

S2203: the first control plane network element receives a second message from the first terminal device, the second message requesting to establish a second connection of the first terminal device with the user plane network element of the first connection; the second connection is used for transmitting data packets of the first connection.

Wherein the second message may be the CPE NAS message in fig. 10-16; the second connection may be a PDU session of the CPE.

S2203 may refer to the description of S1201 or S1501.

S2204: and acquiring the tunnel endpoint identifier of the user plane network element of the first connection and the tunnel endpoint identifier of the user plane network element of the second connection so as to enable connection between the user plane network element of the first connection and the user plane network element of the second connection to be established.

Wherein the tunnel endpoint identification of the user plane network element of the first connection may be RG UPF CN tunnel info in fig. 10-16; the tunnel endpoint identification of the user plane network element of the second connection may be CPE UPF CN tunnel info in fig. 10-16.

S2204 may refer to CPE AMF acquisition RG UPF CN tunnel info and CPE UPF CN tunnel info in fig. 10-16, and send RG UPF CN tunnel info to CPE UPF and CPE UPF CN tunnel info description to RG UPF.

The terminal device shown in fig. 21 may be referred to as a schematic block diagram of the communication apparatus described with reference to fig. 20.

The communication device 2000 is, for example, a first terminal device. The first terminal device comprises a processing module and a transceiver module, and reference is made to the description of fig. 20. For example, the processing module 2010 may be used to perform all operations performed by the first terminal device in the embodiment shown in fig. 21, except for the transceiving operations, e.g., S2103, and/or other procedures for supporting the techniques described herein. The transceiving module 2020 may be used to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 21, e.g., S2101 and S2102, and/or other procedures for supporting the techniques described herein.

The first control plane network element shown in fig. 22 may be referred to as a schematic block diagram of the communication device described in fig. 20.

The communication device 2000 is illustratively a first control plane network element. The first control plane network element 2000 includes a processing module 2010. Optionally, a transceiver module 2020 may also be included. For example, the transceiving module 2020 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 22, e.g., S2201-S2204, and/or other procedures for supporting the techniques described herein.

Referring to fig. 21, a simplified schematic structure of a terminal device is shown, where the transceiver unit 2110 is configured to perform a transmitting operation and a receiving operation on the first terminal device side in the above method embodiment, and the processing unit 2120 is configured to perform operations on the first terminal device other than the transmitting operation and the receiving operation in the above method embodiment.

For example, in one implementation, the processing unit 2110 may be used to perform all operations performed by the first terminal device in the embodiment illustrated in fig. 22, except for the transceiving operations, e.g., S2203, and/or other procedures for supporting the techniques described herein. The transceiving unit 2120 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 22, e.g., S2201 and S2202, and/or other procedures for supporting the techniques described herein.

The embodiment of the application also provides a communication device which can be a terminal device or a circuit. The communication means may be adapted to perform the actions performed by the first terminal device in the above-described method embodiments.

Fig. 23 shows a simplified schematic diagram of the structure of a terminal device when the communication device is a first terminal device. For ease of understanding and ease of illustration, in fig. 23, the terminal device takes CPE as an example. As shown in fig. 23, the terminal device includes a processor, a memory, a wireless or wired connection means, and an input-output means. The processor is mainly used for processing communication protocols and communication data, controlling the terminal equipment, executing software programs, processing data of the software programs and the like. The memory is mainly used for storing software programs and data. The wireless or wired connection device is mainly used for converting and processing wireless signals or wired signals. Input and output devices, such as touch screens, display screens, keyboards, etc., are mainly used for receiving data input by a user and outputting data to the user. It should be noted that some kinds of terminal apparatuses may not have an input/output device.

For ease of illustration, only one memory and processor is shown in fig. 23. In an actual end device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or storage device, etc. The memory may be provided separately from the processor or may be integrated with the processor, which is not limited by the embodiments of the present application.

In the embodiment of the present application, the wireless or wired connection device may be regarded as a transceiver unit of the terminal device (the transceiver unit may be a functional unit capable of implementing a transmitting function and a receiving function, or the transceiver unit may also include two functional units, that is, a receiving unit capable of implementing a receiving function and a transmitting unit capable of implementing a transmitting function, respectively), and a processor having a processing function may be regarded as a processing unit of the terminal device. As shown in fig. 23, the terminal device includes a transceiving unit 2310 and a processing unit 2320. The transceiver unit may also be referred to as a transceiver, transceiver device, etc. The processing unit may also be called a processor, a processing board, a processing module, a processing device, etc. Alternatively, the device for implementing the receiving function in the transceiver unit 2310 may be regarded as a receiving unit, and the device for implementing the transmitting function in the transceiver unit 2310 may be regarded as a transmitting unit, that is, the transceiver unit 2310 includes a receiving unit and a transmitting unit. The transceiver unit may also be referred to as a transceiver, transceiver circuitry, or the like. The receiving unit may also be referred to as a receiver, or receiving circuit, among others. The transmitting unit may also sometimes be referred to as a transmitter, or a transmitting circuit, etc.

It should be understood that, the transceiver 2310 is configured to perform the transmitting operation and the receiving operation on the first terminal device side in the above-described method embodiment, and the processing unit 2320 is configured to perform other operations on the first terminal device other than the transmitting operation in the above-described method embodiment.

For example, in one implementation, the processing unit 2310 may be used to perform all operations performed by the first terminal device in the embodiment shown in fig. 17, except for transceiving operations, e.g., S1703, and/or other procedures for supporting the techniques described herein. The transceiving unit 2320 may be configured to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 17, e.g., S1701 and S1702, and/or other procedures for supporting the techniques described herein.

In another implementation, transceiver unit 2320 may be used to perform all of the transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 18, e.g., S1801 and S1802, and/or other processes for supporting the techniques described herein.

In another implementation, the processing unit 2310 may be used to perform all operations performed by the first terminal device in the embodiment shown in fig. 21, except for transceiving operations, e.g., S2103, and/or other procedures for supporting the techniques described herein. The transceiving unit 2320 may be used to perform all transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 21, e.g., S2101 and S2102, and/or other processes for supporting the techniques described herein.

In another implementation, transceiver unit 2320 may be used to perform all of the transceiving operations performed by the first terminal device in the embodiment illustrated in fig. 22, e.g., S2201-S2204, and/or other processes for supporting the techniques described herein.

When the communication device is a chip-type device or circuit, the device may include a transceiver and a processor. The receiving and transmitting unit can be an input and output circuit and/or a communication interface; the processing unit is an integrated processor or microprocessor or integrated circuit. When the communication apparatus in this embodiment is a terminal device, reference may be made to the device shown in fig. 20. The transceiver may refer to the processing unit 2010 in fig. 20 and perform the corresponding functions; the processor may refer to the transceiving unit 2020 in fig. 20 and perform a corresponding function. When the communication device in this embodiment is a control plane network element, reference may be made to the apparatus shown in fig. 20. The transceiver may refer to the processing unit 2010 in fig. 20 and perform the corresponding functions; the processor may refer to the transceiving unit 2020 in fig. 20 and perform a corresponding function.

The embodiment of the application further provides a communication device, referring to fig. 24, including: processor 2401, communication interface 2402, memory 2403. Wherein the processor 2401, the communication interface 2402, and the memory 2403 may be connected to each other through a bus 2404; bus 2404 may be a PCI bus or an EISA bus, etc. The bus 2404 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in fig. 24, but not only one bus or one type of bus.

The communication device shown in fig. 24 may be a CPE AMF (also referred to as a first control plane network element in fig. 22) shown in fig. 5-24, for performing a corresponding function.

The communication device shown in fig. 24 may be an RG AMF (also referred to as a first control plane network element in fig. 19) shown in fig. 5 to 24, for performing a corresponding function.

The embodiment of the application also provides a communication system, which comprises one or more of the first terminal equipment, the second terminal equipment access network equipment and the first control plane network element.

The present application also provides a computer readable storage medium having instructions stored therein which, when executed on a computer, cause the computer to perform the steps described above as being performed by the CPE (also referred to as the first terminal device) in fig. 5-19 and 21-22.

The present application also provides a computer-readable storage medium having instructions stored therein, which when executed on a computer, cause the computer to perform the steps described above as being performed by an RG (also referred to as a second terminal device) in fig. 5-19 and 21-22.

The present application also provides a computer readable storage medium having instructions stored therein, which when run on a computer, cause the computer to perform the steps described above as being performed by the CPE AMF (also referred to as the first control plane network element in fig. 22) in fig. 5-19 and 21-22.

The present application also provides a computer readable storage medium having instructions stored therein which, when executed on a computer, cause the computer to perform the steps described above as being performed by an RG AMF (also referred to as a first control plane network element in fig. 19) in fig. 5-19 and 21-22.

The present application also provides a computer readable storage medium having instructions stored therein which, when executed on a computer, cause the computer to perform the steps described above as being performed by an RG (also referred to as a second terminal device) in fig. 5-24.

The present application also provides a computer readable storage medium having instructions stored therein, which when run on a computer, cause the computer to perform the steps as described above for CPE AMF (also referred to as first control plane network element in fig. 22) in fig. 5-19 and 21-22.

The present application also provides a computer readable storage medium having instructions stored therein which, when run on a computer, cause the computer to perform the steps described above as being performed by the RG AMF (also referred to as the first control plane network element in fig. 19) in fig. 5-19 and 21-22.

The present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps as performed by the CPE (also referred to as first end device) in fig. 5-19 and 21-22.

The present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps as performed by the RG (also referred to as second terminal device) in fig. 5-19 and 21-22.

The present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps as performed by the CPE AMF (also referred to as first control plane network element in fig. 22) in fig. 5-19 and 21-22.

The present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps as performed by the RG AMF (also referred to as the first control plane network element in fig. 19) of fig. 5-19 and 21-22.

The application also provides a chip comprising a processor. The processor is configured to read and execute the computer program stored in the memory to perform the corresponding operations and/or procedures performed by the service server in the method for transmitting data provided in the present application. Optionally, the chip further comprises a memory, the memory is connected with the processor through a circuit or a wire, and the processor is used for reading and executing the computer program in the memory. Further optionally, the chip further comprises a communication interface, and the processor is connected to the communication interface. The communication interface is used for receiving the processed data and/or information, and the processor acquires the data and/or information from the communication interface and processes the data and/or information. The communication interface may be an input/output interface, interface circuitry, output circuitry, input circuitry, pins, or related circuitry, etc. on the chip. The processor may also be embodied as processing circuitry or logic circuitry.

The application also provides a chip comprising a processor. The processor is configured to read and execute the computer program stored in the memory to perform the corresponding operations and/or procedures performed by the access network device in the method for transmitting data provided in the present application. Optionally, the chip further comprises a memory, the memory is connected with the processor through a circuit or a wire, and the processor is used for reading and executing the computer program in the memory. Further optionally, the chip further comprises a communication interface, and the processor is connected to the communication interface. The communication interface is used for receiving the processed data and/or information, and the processor acquires the data and/or information from the communication interface and processes the data and/or information. The communication interface may be an input/output interface, interface circuitry, output circuitry, input circuitry, pins, or related circuitry, etc. on the chip. The processor may also be embodied as processing circuitry or logic circuitry.

The application also provides a chip comprising a processor. The processor is configured to read and execute the computer program stored in the memory to perform the corresponding operations and/or procedures performed by the policy control network element in the method for transmitting data provided in the present application. Optionally, the chip further comprises a memory, the memory is connected with the processor through a circuit or a wire, and the processor is used for reading and executing the computer program in the memory. Further optionally, the chip further comprises a communication interface, and the processor is connected to the communication interface. The communication interface is used for receiving the processed data and/or information, and the processor acquires the data and/or information from the communication interface and processes the data and/or information. The communication interface may be an input/output interface, interface circuitry, output circuitry, input circuitry, pins, or related circuitry, etc. on the chip. The processor may also be embodied as processing circuitry or logic circuitry.

The application also provides a chip comprising a processor. The processor is configured to read and execute the computer program stored in the memory to perform the corresponding operations and/or procedures performed by the session management network element in the method for transmitting data provided in the present application. Optionally, the chip further comprises a memory, the memory is connected with the processor through a circuit or a wire, and the processor is used for reading and executing the computer program in the memory. Further optionally, the chip further comprises a communication interface, and the processor is connected to the communication interface. The communication interface is used for receiving the processed data and/or information, and the processor acquires the data and/or information from the communication interface and processes the data and/or information. The communication interface may be an input/output interface, interface circuitry, output circuitry, input circuitry, pins, or related circuitry, etc. on the chip. The processor may also be embodied as processing circuitry or logic circuitry.

The chip may be replaced by a chip system, and will not be described herein.

The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. The object of the present embodiment can be achieved by actually selecting some or all of the units therein.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In addition, the term "and/or" in this application is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship; the term "at least one" in this application may mean "one" and "two or more", for example, at least one of A, B and C may mean: the seven cases are that A alone, B alone, C alone, A and B together, A and C together, C and B together, A and B together, and C together.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of connection establishment, comprising:

the method comprises the steps that a first terminal device receives a first message of a second terminal device, wherein the first message requests to establish a first connection between the second terminal device and a data network, the first terminal device is Customer Premise Equipment (CPE), and the second terminal device is a Residential Gateway (RG);

the first terminal equipment forwards the first message to the core network through a control plane between the first terminal equipment and the core network so as to acquire a response of the core network to accept a request to establish the first connection;

the first terminal device establishes or selects a second connection for transmitting data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

2. The method of claim 1, wherein the method further comprises: the first terminal obtains the establishment parameters of the first connection determined by the core network through the control surface;

the first terminal device establishes or selects a second connection for transmitting data of the first connection, including:

the first terminal device establishes or selects the second connection according to the establishment parameters of the first connection.

3. The method of claim 2, wherein the first connection establishment parameters comprise:

the network slice selection auxiliary information NSSAI of the first connection determined by the core network; or,

the data network name DNN of the first connection determined by the core network.

4. The method of claim 1, wherein the method further comprises: the first terminal equipment acquires request establishment parameters of the first connection requested by the second terminal equipment;

the first terminal device establishes or selects the second connection according to the request establishment parameter of the first connection.

5. The method of claim 4, wherein the request to establish parameters for the first connection comprises:

network slice selection assistance information NSSAI of the first connection requested by the second terminal device; or,

the data network name DNN of the first connection requested by the second terminal device.

6. The method according to any of claims 1-5, wherein the first message is a first non-access stratum, NAS, message, the first terminal device forwarding the first message towards a core network through a control plane between the first terminal device and the core network, comprising:

the first terminal device sends a second NAS message to a first control plane network element serving the first terminal device, wherein the second NAS message comprises the first NAS message so as to enable the first control plane network element to send the first NAS message to a second control plane network element serving the second terminal device.

7. The method of any of claims 1-6, wherein the method further comprises:

the first terminal device receives a first data packet of the first connection from the second terminal device;

the first terminal device converts the first data packet into a second data packet of the second connection;

And the first terminal equipment sends the second data packet through the second connection.

8. The method of claim 7, wherein the first terminal device converting the first data packet into a second data packet for the second connection comprises:

the first terminal device sets the source IP address of the first data packet to the IP address of the first terminal device allocated for the second connection.

9. The method of any one of claims 1-8, wherein the method further comprises:

the first terminal device receives a third data packet of the second connection;

the first terminal device converts the third data packet into a fourth data packet of the first connection;

and the first terminal equipment sends the fourth data packet to the second terminal equipment.

10. The method of claim 9, wherein the first terminal device converting the third data packet into a fourth data packet for the first connection comprises:

the first terminal device sets the destination IP address of the third data packet as the IP address of the second terminal device allocated for the first connection.

11. The method according to any of claims 1-10, wherein the first connection is a first protocol data unit, PDU, session of the first terminal device with the data network and the second connection is a second PDU session of the second terminal device with the data network.

12. The method according to any of claims 1-11, wherein the first connection is identical to the data network name, DNN, or network slice selection assistance information, nsaai, of the second connection.

13. A method of connection establishment, comprising:

the first control plane network element acquires a first message of a second terminal device through a second control plane network element of the first terminal device, wherein the first message requests to establish a first connection between the second terminal device and a data network, the first terminal device is Customer Premise Equipment (CPE), and the second terminal device is a Residential Gateway (RG);

the first control plane network element sends the first message to a third control plane network element serving the second terminal device to acquire a response of a core network to a request for establishing the first connection;

the first control plane network element acquires the establishment parameters of the first connection determined by the core network;

the first control plane network element sends the establishment parameters of the first connection to the first terminal equipment so as to enable the first terminal equipment to establish or select a second connection for transmitting the data of the first connection; wherein the second connection is a connection between the first terminal device and the data network.

14. The method of claim 13, wherein the first connection establishment parameters comprise:

15. The method of claim 13 or 14, further comprising:

the first control plane network element participates in the establishment of the second connection.

16. The method according to any of claims 13-15, wherein the first message is a first non-access stratum, NAS, message, and the first control plane network element obtaining, by a control plane with a first terminal device, the first message of a second terminal device, including:

the first control plane network element receives a second NAS message from the first terminal device, where the second NAS message includes the first NAS message.

17. The method of claim 16, wherein the second NAS message further comprises a first identity of the second terminal device;

the method further comprises the steps of: acquiring a second identifier of the second terminal equipment according to the first identifier, wherein the second identifier is an identifier used by the second terminal equipment in a core network, and the mapping relationship between the first identifier and the second identifier is obtained in the process that the second terminal equipment is registered to the network through the first terminal equipment;

The first control plane network element sending the first message to a second control plane network element serving the second terminal device, including: the first control plane network element sends the first message and the second identifier to the second control plane network element.

18. The method according to any of claims 13-17, wherein the first connection is a first protocol data unit, PDU, session of the first terminal device with the data network and the second connection is a second PDU session of the second terminal device with the data network.

19. The method according to any of claims 13-18, wherein the first connection is identical to the data network name, DNN, or network slice selection assistance information, nsaai, of the second connection.

20. A communication device comprising a processor;

the processor is configured to read and execute instructions from the memory to implement the method of any of claims 1-12.

21. A communication device comprising a processor;

the processor is configured to read and execute instructions from the memory to implement the method of any of claims 13-19.

22. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein instructions which, when executed by a processor, implement the method of any of the preceding claims 1-12.

23. A computer readable storage medium having instructions stored therein, which when executed by a processor, implement the method of any of the preceding claims 13-19.