CN117956015A

CN117956015A - Method and device for establishing protocol data unit PDU session

Info

Publication number: CN117956015A
Application number: CN202211292638.8A
Authority: CN
Inventors: 李芸
Original assignee: Shanghai Datang Mobile Communications Equipment Co ltd
Current assignee: Shanghai Datang Mobile Communications Equipment Co ltd
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2024-04-30
Also published as: WO2024082903A1

Abstract

The application provides a method and a device for establishing a protocol data unit PDU session, and relates to the technical field of distributed network architecture and communication. The method comprises the following steps: under the condition that the terminal moves from the first node to the second node, receiving information of a plurality of candidate network functions or identifiers corresponding to the first node, which are sent by the terminal; determining a second network function in the second node based on information of the plurality of candidate network functions or identifiers corresponding to the first node; the second network function is used for establishing PDU session, thereby solving the problem that the continuity of PDU session of the terminal can not be maintained in the distributed network architecture.

Description

Method and device for establishing protocol data unit PDU session

Technical Field

The present application relates to the field of distributed network architecture and communication technologies, and in particular, to a method and an apparatus for establishing a protocol data unit PDU session.

Background

Distributed network architectures typically include a distributed network that includes distributed network nodes. The terminal can be accessed underwater or in deep space through the distributed network nodes.

Currently, in a distributed network architecture, after a terminal moves from one distributed network node to another distributed network node, the continuity of the protocol data unit (protocol data unit, PDU) session of the terminal cannot be maintained.

Therefore, in the distributed network architecture, how to maintain the continuity of the PDU session of the terminal becomes a technical problem to be solved.

Disclosure of Invention

The application provides a method and a device for establishing a protocol data unit PDU session, which are used for solving the defect that the continuity of the PDU session of a terminal cannot be maintained in a distributed network architecture in the prior art and realizing the maintenance of the continuity of the PDU session of the terminal in the distributed network architecture.

In a first aspect, the present application provides a method for establishing a protocol data unit PDU session, applied to a first network function, the method comprising:

Under the condition that the terminal moves from the first node to the second node, receiving information of a plurality of candidate network functions or identifiers corresponding to the first node, which are sent by the terminal;

Determining a second network function in the second node based on information of the plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is used for establishment of a PDU session.

According to the method for establishing a protocol data unit PDU session provided by the present application, a second network function in a second node is determined based on information of a plurality of candidate network functions, comprising:

a second network function is determined among the plurality of candidate network functions based on the information of the plurality of candidate network functions, the plurality of candidate network functions being network functions in the second node.

According to the method for establishing a protocol data unit PDU session provided by the application, the second network function is determined based on the identifier corresponding to the first node, and the method comprises the following steps:

determining a third network function in the first node based on the identifier corresponding to the first node;

acquiring target data network access identifier DNAI information from a third network function; wherein, the data network indicated by the target DNAI information is the data network corresponding to the PDU session;

A second network function is determined within the second node based on the target DNAI information.

According to the method for establishing a protocol data unit PDU session provided by the present application, the identifier corresponding to the first node includes one or more of the following:

a unit identifier of the first node;

identification of the third network function.

According to the method for establishing a protocol data unit PDU session provided by the present application, information of a plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

According to the method for establishing the protocol data unit PDU session provided by the application, the identifier corresponding to the first node is born in the PDU session establishment request.

According to the method for establishing a protocol data unit PDU session provided by the present application, the first network function comprises one or more of the following:

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

In a second aspect, the present application provides a method for establishing a protocol data unit PDU session, applied to a terminal, the method comprising:

Receiving information of a plurality of candidate network functions sent by a third network function in a first node or identifiers corresponding to the first node;

And sending information of the plurality of candidate network functions or the identification corresponding to the first node to the first network function in the second node.

PDU session release message;

PDU session modification message.

In a third aspect, the present application provides a method for establishing a protocol data unit PDU session, applied to a third network function, the method comprising:

acquiring target DNAI information sent by a fourth network function, determining a plurality of candidate network functions in a second node based on the target DNAI information, and sending the information of the plurality of candidate network functions to a terminal; or alternatively

Sending an identifier corresponding to the first node to the terminal; the third network function and the fourth network function belong to the first node.

In a fourth aspect, the present application provides a method for establishing a protocol data unit PDU session, applied to a second network function, the method comprising:

Acquiring target DNAI information;

based on the target DNAI information, the establishment of the PDU session is performed.

According to the method for establishing a protocol data unit PDU session provided by the present application, the target DNAI information is obtained from any one of the following network functions:

A fourth network function within the first node;

A first network function within the second node.

According to the method for establishing a protocol data unit PDU session provided by the present application, under the condition that the target DNAI information is obtained from the fourth network function in the first node, based on the target DNAI information, establishing and executing the establishment of the PDU session includes:

Under the condition that the establishment of the PDU session cannot be continuously executed based on the target DNAI information, the establishment of the PDU session is continuously executed based on the target DNAI information and the target network function; wherein the target network function is a network function selected by a third network function within the first node that performs establishment of a PDU session in conjunction with the second network function.

In a fifth aspect, the present application provides a first communication device having a first network function, the first communication device comprising: memory, transceiver, processor;

A memory for storing a computer program;

a transceiver for transceiving data under the control of the processor;

a processor for reading the computer program in the memory and performing the following operations:

According to the first communication device provided by the application, the processor is specifically configured to:

According to the first communication device provided by the application, the identifier corresponding to the first node comprises one or more of the following:

a unit identifier of the first node;

identification of the third network function.

According to a first communication device provided by the application, information of a plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

According to the first communication device provided by the application, the identifier corresponding to the first node is born in the PDU session establishment request.

According to a first communication device provided by the application, the first network function comprises one or more of the following:

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

In a sixth aspect, the present application provides a terminal, including: memory, transceiver, processor;

A memory for storing a computer program;

a transceiver for transceiving data under the control of the processor;

According to a terminal provided by the application, information of a plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

According to the terminal provided by the application, the identifier corresponding to the first node is born in the PDU session establishment request.

In a seventh aspect, the present application provides a third communication device comprising a third network function, the third communication device comprising: memory, transceiver, processor;

A memory for storing a computer program;

a transceiver for transceiving data under the control of the processor;

In an eighth aspect, the present application provides a second communication device comprising a second network function, the second communication device comprising: memory, transceiver, processor;

A memory for storing a computer program;

a transceiver for transceiving data under the control of the processor;

Acquiring target DNAI information;

According to a second communication device provided by the present application, the target DNAI information is acquired from any one of the following network functions:

A fourth network function within the first node;

A first network function within the second node.

According to the second communication device provided by the application, in the case of acquiring the target DNAI information from the fourth network function in the first node, the processor is specifically configured to:

In a ninth aspect, the present application provides an apparatus for establishing a protocol data unit PDU session, applied to a first network function, the apparatus comprising:

the receiving module is used for receiving information of a plurality of candidate network functions or identifiers corresponding to the first node sent by the terminal under the condition that the terminal moves from the first node to the second node;

A determining module, configured to determine a second network function in the second node based on information of the plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is used for establishment of a PDU session.

According to the device for establishing the protocol data unit PDU session provided by the application, the determining module is specifically used for:

According to the device for establishing the protocol data unit PDU session provided by the application, the identifier corresponding to the first node comprises one or more of the following:

a unit identifier of the first node;

identification of the third network function.

According to the device for establishing a protocol data unit PDU session provided by the present application, information of a plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

According to the device for establishing the protocol data unit PDU session provided by the application, the identifier corresponding to the first node is born in the PDU session establishment request.

According to the application, the first network function comprises one or more of the following:

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

In a tenth aspect, the present application provides an apparatus for establishing a protocol data unit PDU session, applied to a terminal, the apparatus comprising:

the receiving module is used for receiving information of a plurality of candidate network functions transmitted by a third network function in the first node or identifiers corresponding to the first node;

And the sending module is used for sending the information of the plurality of candidate network functions or the identification corresponding to the first node to the first network function in the second node.

PDU session release message;

PDU session modification message.

In an eleventh aspect, the present application provides an apparatus for establishing a protocol data unit PDU session, applied to a third network function, the apparatus comprising:

the acquisition module is used for acquiring target DNAI information sent by the fourth network function; a determining module for determining a plurality of candidate network functions in the second node based on the target DNAI information; a sending module, configured to send information of a plurality of candidate network functions to a terminal; or alternatively

The sending module is used for sending the identifier corresponding to the first node to the terminal; the third network function and the fourth network function belong to the first node.

In a twelfth aspect, the present application provides an apparatus for establishing a protocol data unit PDU session, applied to a second network function, the apparatus comprising:

The acquisition module is used for acquiring the target DNAI information;

and the execution module is used for executing the establishment of the PDU session based on the target DNAI information.

According to the device for establishing a protocol data unit PDU session provided by the present application, the target DNAI information is obtained from any one of the following network functions:

A fourth network function within the first node;

A first network function within the second node.

According to the device for establishing a protocol data unit PDU session provided by the present application, when the target DNAI information is acquired from the fourth network function in the first node, the execution module is specifically configured to:

In a thirteenth aspect, the present application also provides a processor readable storage medium storing a computer program which, when executed by a processor, implements a method for establishing a protocol data unit, PDU, session as described above.

In a fourteenth aspect, the present application also provides a computer program product comprising a computer program which, when executed by a processor, implements a method for establishing a protocol data unit, PDU, session as described in any of the above.

In the method and the device for establishing the PDU session of the protocol data unit, the first network function determines the second network function in the second node based on the received information of a plurality of candidate network functions transmitted by the terminal or the identification corresponding to the first node under the condition that the terminal is positioned in the second node, so that the second network function executes the establishment of the PDU session of the terminal, and the PDU session continuity of the terminal can be ensured by establishing the PDU session, thereby solving the problem that the PDU session continuity of the terminal cannot be maintained in a distributed network architecture.

Drawings

In order to more clearly illustrate the application or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the application, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a distributed network architecture provided in the present application;

fig. 2 is a schematic flow chart of a method for establishing a PDU session according to the present application;

FIG. 3 is a second flow chart of a PDU session establishment method according to the present application;

FIG. 4 is a third flow chart of a PDU session establishment method according to the present application;

FIG. 5 is a flow chart of a PDU session establishment method according to the present application;

FIG. 6 is one of the interactive flow diagrams of the PDU session establishment method provided by the present application;

FIG. 7 is a second schematic diagram of an interaction flow of the PDU session establishment method provided by the present application;

FIG. 8 is a third schematic diagram of an interaction flow of the PDU session establishment method provided by the present application;

fig. 9 is a schematic structural diagram of a PDU session establishment apparatus according to the present application;

FIG. 10 is a second schematic diagram of a PDU session establishment apparatus according to the present application;

FIG. 11 is a third schematic diagram of a PDU session establishment apparatus according to the present application;

FIG. 12 is a diagram showing a PDU session establishment apparatus according to the present application;

fig. 13 is a schematic physical structure of a first communication device according to the present application;

Fig. 14 is a schematic diagram of the physical structure of the terminal provided by the present application;

fig. 15 is a schematic physical structure of a third communication device according to the present application;

Fig. 16 is a schematic physical structure of a second communication device according to the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

In the embodiment of the application, the term "and/or" describes the association relation of the association objects, which means that three relations can exist, for example, a and/or B can be expressed as follows: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The term "plurality" in embodiments of the present application means two or more, and other adjectives are similar.

The terminal according to the embodiment of the application can be a device for providing voice and/or data connectivity for a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem, etc. The names of the terminal devices may also be different in different systems, for example in a 5G system, the terminal devices may be referred to as User Equipment (UE). The wireless terminal device may communicate with one or more Core Networks (CNs) via a radio access Network (Radio Access Network, RAN), which may be mobile terminal devices such as mobile phones (or "cellular" phones) and computers with mobile terminal devices, e.g., portable, pocket, hand-held, computer-built-in or vehicle-mounted mobile devices that exchange voice and/or data with the radio access Network. Such as Personal communication services (Personal Communication Service, PCS) phones, cordless phones, session initiation protocol (Session Initiated Protocol, SIP) phones, wireless local loop (Wireless Local Loop, WLL) stations, personal digital assistants (Personal DIGITAL ASSISTANT, PDA) and the like. The wireless terminal device may also be referred to as a system, subscriber unit (subscriber unit), subscriber station (subscriber station), mobile station (mobile station), remote station (remote station), access point (access point), remote terminal device (remote terminal), access terminal device (ACCESS TERMINAL), user terminal device (user terminal), user agent (user agent), user equipment (user device), and embodiments of the present application are not limited.

The communication device (e.g., communication device) according to the embodiments of the present application may be a base station, which may include a plurality of cells for serving a terminal. A base station may also be called an access point or may be a device in an access network that communicates over the air-interface, through one or more sectors, with wireless terminal devices, or other names, depending on the particular application. The communication device may be configured to exchange received air frames with internet protocol (Internet Protocol, IP) packets as a router between the wireless terminal device and the rest of the access network, which may include an Internet Protocol (IP) communication network. The communication device may also coordinate attribute management for the air interface. For example, the communication device according to the embodiment of the present application may be a communication device (Base Transceiver Station, BTS) in a global system for mobile communications (Global System for Mobile communications, GSM) or code division multiple access (Code Division Multiple Access, CDMA), a communication device (NodeB) in a wideband code division multiple access (Wide-band Code Division Multiple Access, WCDMA), an evolved communication device (evolutional Node B, eNB or e-NodeB) in a long term evolution (long term evolution, LTE) system, a 5G base station (gNB) in a 5G network architecture (next generation system), a home evolved base station (Home evolved Node B, heNB), a relay node (relay node), a home base station (femto), a pico base station (pico), and the like. In some network structures, the communication device may include a centralized unit (centralized unit, CU) node and a Distributed Unit (DU) node, which may also be geographically separated.

Multiple-input Multiple-output (Multi Input Multi Output, MIMO) transmissions may each be made between the communication device and the terminal device using one or more antennas, and the MIMO transmissions may be Single-User MIMO (SU-MIMO) or Multiple-User MIMO (MU-MIMO). The MIMO transmission may be 2D-MIMO, 3D-MIMO, FD-MIMO, or massive-MIMO, or may be diversity transmission, precoding transmission, beamforming transmission, or the like, depending on the form and number of the root antenna combinations.

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The distributed network architecture to which the invention relates will first be described with reference to fig. 1.

Fig. 1 is a schematic structural diagram of a distributed network architecture provided in the present application. As shown in fig. 1, the distributed network architecture includes routers and a distributed network.

The distributed network includes distributed network nodes.

The terminal can be accessed underground, deep space, land and underwater through distributed network nodes in the distributed network.

Currently, in the distributed network architecture shown in fig. 1, after a terminal moves from one distributed network node to another distributed network node, the continuity of the protocol data unit (protocol data unit, PDU) session of the terminal cannot be maintained.

In the related art, the continuity of PDU sessions of a terminal is generally implemented using mode2 (mode 2) or mode3 (mode 3) of session AND SERVICE continuity (SSC) of session and service. In the related art described above, in the case where the continuity of the PDU session of the terminal is achieved in the mode2 or the mode3 of the SSC, the access and mobility management function (ACCESS AND mobility management function, AMF) is generally unchanged.

However, in the distributed network architecture, after the terminal moves from one distributed network node to another distributed network node, the AMF generally changes, so that the continuity of PDU session of the terminal cannot be achieved using the mode 2 or the mode 3 of SSC in the related art.

The embodiment of the application provides a PDU session establishment method and device, which are used for solving the problem of maintaining the PDU session continuity of a terminal in a distributed network architecture. The method and the device are based on the same application, and because the principles of solving the problems by the method and the device are similar, the implementation of the device and the method can be referred to each other, and the repetition is not repeated.

Fig. 2 is a flow chart of a method for establishing a PDU session according to the present application. As shown in fig. 2, the method includes:

Step 201, in the case that the terminal moves from the first node to the second node, the first network function receives information of a plurality of candidate network functions or identifiers corresponding to the first node, which are sent by the terminal.

Optionally, the first node and the second node are different distributed network nodes, and the different distributed nodes may specifically be different micro cloud units (SCUs).

The first network function is a network function in the second node.

The plurality of candidate network functions are network functions in the second node.

Optionally, the information of the plurality of candidate network functions may include an identification of the plurality of candidate network functions.

For example, the identity of the candidate network function may be an identification number (Identity document, ID), address information, or the like.

For example, the identification corresponding to the first node may be an ID.

Step 202, the first network function determines a second network function in the second node based on information of a plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is used for establishment of a PDU session.

In the method for establishing a PDU session provided in the embodiment of fig. 2, when the terminal is located in the second node, the first network function determines, based on the received information of multiple candidate network functions sent by the terminal or the identifier corresponding to the first node, the second network function in the second node, so that the second network function performs establishment of the PDU session of the terminal, thereby guaranteeing continuity of the PDU session of the terminal.

Optionally, determining the second network function in the second node based on the information of the plurality of candidate network functions comprises:

The plurality of candidate Network functions are Data networks capable of serving the target Data Network access identifier (Data Network ACCESS IDENTIFIER, DNAI) information indication.

The target DNAI information is information obtained by a third network function in the first node from a fourth network function in the first node.

Optionally, determining the second network function based on the identifier corresponding to the first node includes:

Optionally, the identifier corresponding to the first node may be one or more of the following:

a unit identifier of the first node;

identification of the third network function.

Optionally, the information of the plurality of candidate network functions is carried in any one of the following messages:

A PDU session release message (PDU Session Release Command);

PDU session modification message (PDU Session Modification Command).

Optionally, in SSC mode 2, the PDU session release message may carry information of a plurality of candidate network functions; in SSC mode 3, the PDU session modification message may carry information of a plurality of candidate network functions.

Specifically, in SSC mode 2, the terminal sends a PDU session release message to the first network function, where the PDU session release message carries information of multiple candidate network functions; in SSC mode 3, the terminal sends a PDU session modification message to the first network function, the PDU session modification message carrying information of a plurality of candidate network functions.

Alternatively, the cause (cause) value in the PDU session release message and the PDU session modification message may carry information of a plurality of candidate network functions.

Optionally, the identification corresponding to the first node is carried in a PDU establishment (PDU Session Establishment) request. Specifically, the terminal sends a PDU session establishment request to the first network function, where the PDU session establishment request carries an identifier corresponding to the first node

Optionally, the first network function includes one or more of:

An access and mobility management function AMF;

unified data management (Unified DATA MANAGEMENT, UDM);

Policy control function (Policy Control function, PCF).

In the PDU session establishment method provided by the application, the first network function can be AMF, UDM or PCF, so that the flexibility of determining the second network function is improved.

Fig. 3 is a second flowchart of a PDU session establishment method according to the present application. As shown in fig. 3, the method includes:

Step 301, the terminal receives information of a plurality of candidate network functions sent by a third network function in the first node or an identifier corresponding to the first node.

Step 302, the terminal sends information of a plurality of candidate network functions or identifiers corresponding to the first node to the first network function in the second node.

In the method for establishing a PDU session provided in the embodiment of fig. 3, the third network function sends, to the first network function, information of a plurality of candidate network functions or identifiers corresponding to the first node through the terminal, so that the first network function can determine the second network function based on the information of the plurality of candidate network functions or the identifiers corresponding to the first node, and further, after the terminal moves from the first node to the second node, the continuity of the PDU session of the terminal can be ensured.

PDU session release message;

PDU session modification message.

Optionally, the identifier corresponding to the first node is carried in a PDU session release message. Specifically, the third network function in the first node sends a PDU session release message to the terminal, where the PDU session release message carries an identifier corresponding to the first node.

Optionally, the identifier corresponding to the first node is carried in a PDU session establishment request. Specifically, the terminal sends a PDU session establishment request to the first network function, where the PDU session establishment request carries an identifier corresponding to the first node.

Fig. 4 is a third flow chart of a PDU session establishment method according to the present application. As shown in fig. 4, the method includes:

Step 401, the third network function obtains the target DNAI information sent by the fourth network function, determines a plurality of candidate network functions in the second node based on the target DNAI information, and sends the information of the plurality of candidate network functions to the terminal; or sending the identification corresponding to the first node to the terminal.

The third network function and the fourth network function belong to the first node.

The first node is the node where the terminal is located before the second node.

Optionally, determining a plurality of candidate network functions in the second node based on the target DNAI information includes:

determining a second node based on the target DNAI information;

And selecting a plurality of candidate network functions in the second node capable of serving the data network indicated by the target DNAI information.

Fig. 5 is a flowchart illustrating a method for establishing a PDU session according to the present application. As shown in fig. 5, the method includes:

step 501, the second network function obtains the target DNAI information.

Step 502, the second network function performs the establishment of the PDU session based on the target DNAI information.

It should be noted that, performing the establishment of the PDU session may implement the establishment of the user plane path between the terminal and the data network indicated by the target DNAI information.

In the method for establishing a PDU session provided in the embodiment of fig. 5, the second network function in the second node where the terminal is currently located may target DNAI information, and perform establishment of the PDU session based on the target DNAI information, so as to ensure continuity of the PDU session of the terminal.

Optionally, the target DNAI information is obtained from any one of the following network functions:

A fourth network function within the first node;

A first network function within the second node.

Optionally, in the case of acquiring the target DNAI information from the fourth network function in the first node, step 502 specifically includes:

Based on the above embodiments, in the following, the information interaction process among the terminal, the first network function, the second network function, the third network function, and the fourth network function will be described by taking the first network function as a new AMF, the second network function as a new SMF, the third network function as an old AMF, and the fourth network function as an old SMF as an example in combination with the specific embodiments.

First, referring to fig. 6, an example of SSC mode 2 is taken to describe a method for establishing a PDU session according to the present application.

Fig. 6 is one of the interactive flow diagrams of the PDU session establishment method provided by the present application. As shown in fig. 6, the method includes:

step 601, the old SMF decides to change the user plane function (User Plane Function, UPF).

Step 602, transmitting SM context state notification request/Response (Nsmf _ PDUSession _ SMContextStatusNotify Request/Response) between the old SMF and the old AMF.

Specifically, the old SMF receives the target DNAI information from the SM-PCF, and in the event that the UPF (PSA) cannot connect to the data network indicated by this target DNAI information, the old SMF invokes Nsmf _ PDUSession _ SMContextStatusNotify Request service operations to the old AMF.

Nsmf _ PDUSession _ SMContextStatusNotify Request carries target DNAI information.

The old AMF may send Nsmf _ PDUSession _ SMContextStatusNotify to the old SMF.

Step 603, the old AMF determines a plurality of candidate network functions.

The old AMF determines a plurality of candidate network functions based on the target DNAI information in the preset request.

Step 604, the old AMF sends a PDU session release command to the terminal (UE), where the PDU session release command carries information of a plurality of candidate network functions.

Optionally, the old AMF may further send a first preset message to the terminal, where the first preset message includes a PDU session release command and information of a plurality of candidate network functions (i.e., SMF(s) info).

Step 605, the terminal sends a PDU session establishment request to the new AMF, where the PDU session establishment request carries information of multiple candidate network functions.

Optionally, in case the terminal is connected to the second node through a new (R) AN, initiating a PDU session establishment procedure to the new AMF and carrying information of the plurality of candidate network functions.

Step 606, the new AMF determines a new SMF in the second node based on the information of the plurality of candidate network functions.

Alternatively, the new AMF selects an appropriate SMF from among a plurality of candidate network functions as the SMF (i.e., new SMF) of the PDU session.

Step 607, execute the PDU session setup procedure (with the new UPF).

The establishment procedure for executing the PDU session includes: the new SMF determines a new UPF based on the target DNAI information acquired from the new AMF, and triggers a user plane path establishment procedure for the terminal and the new UPF to initiate a PDU session.

Next, referring to fig. 7, a description will be given of a method for establishing a PDU session according to the present application, taking SSC mode 3 as an example.

Fig. 7 is a second schematic diagram of an interaction flow of the PDU session establishment method provided by the present application. As shown in fig. 7, the method includes:

step 701, the old SMF decides that the UPF or SMF of the service needs to be changed.

Step 702, transmitting SM context state notification request/Response (Nsmf _ PDUSession _ SMContextStatusNotify Request/Response) between the old SMF and the old AMF.

Nsmf _ PDUSession _ SMContextStatusNotify Request carries information of the target DNAI.

Step 703, performing a second preset message transmission between the old SMF and the old AMF.

The second preset message is Namf _communication_n1n MESSAGETRANSFER.

The second preset message includes: PDU session ID (PDU Session ID), SMF reassignment request indication (SMF Reallocation requested indication), N1 SM container (N1 SM container).

The PDU session modification message is included in the N1 SM container.

The PDU Session modification command includes a cause value and a protocol configuration option (Protocol Configuration Option, PCO) (e.g., a PDU Session address lifetime value (PDU Session ADDRESS LIFETIME value)).

Step 704, the old AMF determines a plurality of candidate network functions.

Specifically, the execution method of step 704 is the same as that of step 603, and will not be described here again.

Step 705, the old AMF sends a PDU session modification message to the terminal, where the PDU session modification message carries information of a plurality of candidate network functions.

Step 706, the terminal sends a PDU session modification message acknowledgement to the old AMF (PDU Session Modification Command ACK).

Step 707, the old AMF sends a PDU session update SM context request (Nsmf _ PDUSession _ UpdateSMContext Request) to the old SMF.

Step 708, the old SMF sends a PDU session update SM context response (Nsmf _ PDUSession _ UpdateSMContext Response) to the old AMF.

Step 709, the terminal sends a PDU session establishment request to the new AMF, where the PDU session establishment request carries information of multiple candidate network functions.

Optionally, the terminal may further send second preset information to the new AMF, where the second preset information includes a PDU session establishment request and information of a plurality of candidate network functions.

Step 710, the new AMF determines a new SMF in the second node based on the information of the plurality of candidate network functions.

Step 711, the terminal and the new UPF start the establishment flow of PDU session.

Specifically, the new SMF acquires the target DNAI information from the new AMF, selects a new UPF based on the target DNAI information, and further triggers the establishment procedure of the PDU session initiated by the terminal and the new UPF.

Step 712, uplink and downlink Data (UL/DL Data) transmission is performed between the terminal and the new UPF.

Step 713, the release procedure of the PDU session is performed between the terminal and the old UPF.

Fig. 8 is a third schematic diagram of an interaction flow of the PDU session establishment method according to the present application. As shown in fig. 8, the method includes:

Step 801, old SMF decides to change UPF.

The SM context state notification request/Response (Nsmf _ PDUSession _ SMContextStatusNotify Request/Response) is transmitted between the old SMF and the old AMF, step 802.

Step 803, the release procedure of the PDU session is performed between the terminal and the old UPF.

Step 804, the old AMF sends a PDU session release command to the terminal, where the PDU session release command carries an identifier corresponding to the first node.

Step 805, the terminal sends a PDU session establishment command to the new AMF, where the PDU session establishment command carries an identifier corresponding to the first node.

Step 806, the new AMF initiates the establishment of the association relationship with the old AMF, so that the new AMF can acquire the target DNAI information from the new AMF and the old AMF.

Step 807, the new AMF determines a new SMF in the second node based on the identification corresponding to the first node.

Step 808, execute the PDU session establishment procedure.

Specifically, the new SMF acquires the target DNAI information from the new AMF, and selects a new UPF based on the target DNAI information, so as to trigger the establishment procedure of the PDU session between the terminal and the new UPF.

Fig. 8 is a method for establishing a PDU session based on SSC pattern 2. Optionally, the method for establishing the PDU session (the specific process is similar to that of fig. 8) may also be based on SSC mode 3, and will not be described herein.

In some embodiments, after the terminal initiates the PDU session establishment request in the second node, the new AMF selects a new SMF according to the prior art, and the new SMF establishes a direct association with the old SMF in the first node, so that the new SMF may directly obtain the target DNAI information from the old SMF, and select a new UPF based on the target DNAI information, thereby triggering an establishment procedure of the PDU session between the terminal and the new UPF.

In some embodiments, if the new SMF acquires the target DNAI information in the old SMF based on the new AMF selecting a new SMF according to the prior art, it is determined that a user plane path between the data networks indicated by the target DNAI information cannot be established for the current PDU session (i.e., the establishment of the PDU session is performed successfully), where the new AMF selects a target network function (i.e., the I-SMF), the I-SMF needs to satisfy the user plane path between the data networks indicated by the information capable of being cooperatively established with the new SMF to the target DNAI (i.e., the establishment of the PDU session is performed successfully).

The following describes the device for establishing a protocol data unit PDU session provided by the present application, and the device for establishing a protocol data unit PDU session described below and the method for establishing a protocol data unit PDU session described above can be referred to correspondingly.

Fig. 9 is a schematic structural diagram of a PDU session establishment apparatus according to the present application. The PDU session establishment means 90 is applied to a first network function, the PDU session establishment means 90 comprising:

a receiving module 910, configured to receive, when the terminal moves from the first node to the second node, information of multiple candidate network functions or an identifier corresponding to the first node sent by the terminal;

a determining module 920, configured to determine a second network function in the second node based on information of the plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is used for establishment of a PDU session.

According to the device for establishing a protocol data unit PDU session provided by the present application, the determining module 920 is specifically configured to:

a unit identifier of the first node;

identification of the third network function.

PDU session release message;

PDU session modification message.

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

It should be noted that, the PDU session establishment device 90 provided in this embodiment of the present application can implement all the method steps implemented by the method embodiment of the first network function, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those of the method embodiment in this embodiment are omitted.

Fig. 10 is a second schematic structural diagram of a PDU session establishment apparatus according to the present application. The PDU session establishment apparatus 100 is applied to a terminal, and the PDU session establishment apparatus 100 includes:

A receiving module 110, configured to receive information of a plurality of candidate network functions or identifiers corresponding to the first node, where the information is sent by a third network function in the first node;

and the sending module 120 is configured to send information of the plurality of candidate network functions or an identifier corresponding to the first node to the first network function in the second node.

PDU session release message;

PDU session modification message.

According to the device for establishing the protocol data unit PDU session provided by the application, the identifier corresponding to the first node is born in the PDU session release message.

It should be noted that, the PDU session establishment apparatus 100 provided in this embodiment of the present application can implement all the method steps implemented by the method embodiment executed by the terminal and achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those of the method embodiment in this embodiment are omitted.

Fig. 11 is a third schematic structural diagram of a PDU session establishment apparatus according to the present application. The PDU session establishment means 200 is applied to a third network function, the PDU session establishment means 200 comprising:

an obtaining module 210, configured to obtain target DNAI information sent by the fourth network function; a determining module for determining a plurality of candidate network functions in the second node based on the target DNAI information; a sending module, configured to send information of a plurality of candidate network functions to a terminal; or alternatively

A sending module 220, configured to send an identifier corresponding to the first node to the terminal; the third network function and the fourth network function belong to the first node.

It should be noted that, the PDU session establishment apparatus 200 provided in this embodiment of the present application can implement all the method steps implemented in the method embodiment of the third network function, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those in the method embodiment in this embodiment are omitted.

Fig. 12 is a schematic diagram of a PDU session establishment apparatus according to the present application. The PDU session establishment means 300 is applied to a second network function, the PDU session establishment means 300 comprising:

An obtaining module 310, configured to obtain target DNAI information;

An execution module 320 is configured to execute establishment of a PDU session based on the target DNAI information.

A fourth network function within the first node;

A first network function within the second node.

According to the device for establishing a protocol data unit PDU session provided by the present application, when the target DNAI information is acquired from the fourth network function in the first node, the execution module 320 is specifically configured to:

It should be noted that, the PDU session establishment apparatus 300 provided in this embodiment of the present application can implement all the method steps implemented in the method embodiment of the second network function, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those in the method embodiment in this embodiment are omitted.

It should be noted that, in the embodiment of the present application, the division of the units (modules) is schematic, which is merely a logic function division, and other division manners may be implemented in actual practice. In addition, each functional unit in the embodiments 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 integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a processor-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or 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.) or a processor (processor) to execute all or part of the steps of the method according to 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.

Fig. 13 is a schematic physical structure of a first communication device according to the present application. The first communication device has a first network function. As shown in fig. 13, the first communication device may include: a processor 1310, a transceiver (Communications Interface) 1320, and a memory (memory) 1330.

The memory 1330 is used to store computer programs. The transceiver 1320 is configured to transmit and receive data under the control of the processor 1310. The processor 1310 is configured to read a computer program in the memory 1330 to perform the following operations: under the condition that the terminal moves from the first node to the second node, receiving information of a plurality of candidate network functions or identifiers corresponding to the first node, which are sent by the terminal; determining a second network function in the second node based on information of the plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is used for establishment of a PDU session.

In particular, a transceiver 1320 is provided for receiving and transmitting data under the control of the processor 1310.

Wherein in fig. 13, a bus architecture may comprise any number of interconnected buses and bridges, and in particular one or more processors represented by processor 1310 and various circuits of memory represented by memory 1330, linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 1320 may be a number of elements, including a transmitter and a receiver, providing a means for communicating with various other apparatus over transmission media, including wireless channels, wired channels, optical cables, and the like. The processor 1310 is responsible for managing the bus architecture and general processing, and the memory 1330 may store data used by the processor 1310 in performing operations.

The processor 1310 may be a central processing unit (Central Processing Unit, CPU), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), or complex Programmable logic device (Complex Programmable Logic Device, CPLD), and may also employ a multi-core architecture.

According to a first communication device provided by the present application, the processor 1310 is specifically configured to:

a unit identifier of the first node;

identification of the third network function.

PDU session release message;

PDU session modification message.

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

It should be noted that, the first communication device provided in this embodiment of the present application can implement all the method steps implemented in the method embodiment of the first network function, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those in the method embodiment in this embodiment are omitted.

Fig. 14 is a schematic physical structure of a terminal according to the present application. As shown in fig. 14, the terminal may include: a processor 1410, a transceiver (Communications Interface) 1420, and a memory 1430.

Memory 1430 is used to store computer programs; the transceiver 1420 is used to transmit and receive data under the control of the processor 1410. The processor 1410 is configured to read a computer program in the memory 1430 to perform the following method including: receiving information of a plurality of candidate network functions sent by a third network function in a first node or identifiers corresponding to the first node; and sending information of the plurality of candidate network functions or the identification corresponding to the first node to the first network function in the second node.

In particular, a transceiver 1420 is used to receive and transmit data under the control of a processor 1410.

Where in FIG. 14, a bus architecture may comprise any number of interconnected buses and bridges, with various circuits of the one or more processors, as represented by processor 1410, and the memory, as represented by memory 1430, being linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 1420 may be a number of elements, i.e., include a transmitter and a receiver, providing a means for communicating with various other apparatus over transmission media, including wireless channels, wired channels, optical cables, and the like. The user interface 1440 may also be an interface capable of interfacing with an inscribed desired device for a different user device, including but not limited to a keypad, display, speaker, microphone, joystick, etc.

The processor 1410 is responsible for managing the bus architecture and general processing, and the memory 1430 may store data used by the processor 1410 in performing operations.

Alternatively, the processor 1410 may be a central processing unit (Central Processing Unit, CPU), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), or complex Programmable logic device (Complex Programmable Logic Device, CPLD), and the processor may also employ a multi-core architecture.

The processor is operable to perform any of the methods provided by embodiments of the present application in accordance with the obtained executable instructions by invoking a computer program stored in a memory. The processor and the memory may also be physically separate.

PDU session release message;

PDU session modification message.

According to the terminal provided by the application, the identifier corresponding to the first node is born in the PDU session release message.

It should be noted that, the terminal provided by the embodiment of the present application can implement all the method steps implemented by the method embodiment executed by the terminal, and can achieve the same technical effects, and the same parts and beneficial effects as those of the method embodiment in the embodiment are not described in detail herein.

Fig. 15 is a schematic physical structure of a third communication device according to the present application. The third communication device includes a third network function, as shown in fig. 15, and may include: a processor 1510, a transceiver (Communications Interface) 1520, and a memory 1530.

The memory 1530 is used for storing computer programs. The transceiver 1520 is configured to transmit and receive data under the control of the processor 1510. The processor 1510 is configured to read a computer program in the memory 1530 to perform the following operations: acquiring target DNAI information sent by a fourth network function, determining a plurality of candidate network functions in a second node based on the target DNAI information, and sending the information of the plurality of candidate network functions to a terminal; or sending the identification corresponding to the first node to the terminal; the third network function and the fourth network function belong to the first node.

In particular, a transceiver 1520 for receiving and transmitting data under the control of a processor 1510.

Wherein in fig. 15, a bus architecture may comprise any number of interconnected buses and bridges, and in particular one or more processors represented by processor 1510 and various circuits of memory represented by memory 1530. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 1520 may be a number of elements, i.e., include a transmitter and a receiver, providing a means for communicating with various other apparatus over a transmission medium, including wireless channels, wired channels, optical cables, and the like. The processor 1510 is responsible for managing the bus architecture and general processing, and the memory 1530 may store data used by the processor 1510 in performing operations.

The processor 1510 may be a central processing unit (Central Processing Unit, CPU), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), or complex Programmable logic device (Complex Programmable Logic Device, CPLD), or the processor may employ a multi-core architecture.

It should be noted that, the third communication device provided in this embodiment of the present application can implement all the method steps implemented in the method embodiment of the third network function, and can achieve the same technical effects, and specific details of the same parts and beneficial effects as those of the method embodiment in this embodiment are not repeated herein.

Fig. 16 is a schematic physical structure of a second communication device according to the present application. The second communication device includes a second network function, as shown in fig. 16, and may include: a processor 1610, a transceiver (Communications Interface) 1620, a memory (memory) 1630, and a communication bus 1640, wherein the processor 1610, the transceiver 1620, and the memory 1630 complete communication with each other through the communication bus 1640.

Memory 1630 is used for storing computer programs. The transceiver 1620 is configured to transmit and receive data under the control of the processor 1610. Processor 1610 is configured to read a computer program in memory 1630 to perform a method for establishing a protocol data unit, PDU, session, the method comprising: acquiring target DNAI information; based on the target DNAI information, the establishment of the PDU session is performed.

In particular, transceiver 1620 is configured to receive and transmit data under the control of processor 1610.

Where in FIG. 16, a bus architecture may comprise any number of interconnected buses and bridges, with various circuits of the one or more processors, specifically represented by processor 1610, and the memory, represented by memory 1630, linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 1620 may be a number of elements, including a transmitter and a receiver, providing a means for communicating with various other apparatus over a transmission medium, including wireless channels, wired channels, optical cables, etc. The processor 1610 is responsible for managing the bus architecture and general processing, and the memory 1630 may store data used by the processor 1610 in performing operations.

Processor 1610 may be a central processing unit (Central Processing Unit, CPU), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), or complex Programmable logic device (Complex Programmable Logic Device, CPLD), which may also employ a multi-core architecture.

A fourth network function within the first node;

A first network function within the second node.

According to a second communication device provided in the present application, in the case of acquiring the target DNAI information from the fourth network function in the first node, the processor 1630 is specifically configured to:

It should be noted that, the second communication device provided in this embodiment of the present application can implement all the method steps implemented in the method embodiment of the second network function, and can achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those in the method embodiment in this embodiment are omitted.

Further, the logic instructions in the above-described memory 1330, memory 1430, memory 1530, and memory 1630 may be implemented in the form of software functional units and may be stored in a computer-readable storage medium when sold or used as a separate product. Based on this 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, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method of the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In another aspect, the present application further provides a computer program product, where the computer program product includes a computer program, where the computer program can be stored on a storage medium readable by a processor, and when the computer program is executed by the processor, the computer program can execute the method for setting up a PDU session provided by the foregoing method embodiments.

In yet another aspect, the present application further provides a processor readable storage medium storing a computer program, which when executed by a processor is implemented to perform the method for establishing a PDU session provided by the above method embodiments.

Among other things, processor-readable storage media can be any available medium or data storage device that can be accessed by a processor, including but not limited to magnetic storage (e.g., floppy disks, hard disks, tapes, magneto-optical disks (MOs), etc.), optical storage (e.g., CD, DVD, BD, HVD, etc.), and semiconductor storage (e.g., ROM, EPROM, EEPROM, nonvolatile storage (NAND FLASH), solid State Disk (SSD)), etc.

The apparatus embodiments described above are merely illustrative, wherein elements illustrated as separate elements may or may not be physically separate, and elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.

From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on such understanding, the foregoing technical solutions may be embodied essentially or in part in the form of a software product, which may be stored in a computer-readable storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the various embodiments or methods of some parts of the embodiments.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A method for establishing a protocol data unit, PDU, session, applied to a first network function, the method comprising:

Under the condition that a terminal moves from a first node to a second node, receiving information of a plurality of candidate network functions sent by the terminal or identifiers corresponding to the first node;

Determining a second network function in the second node based on the information of the plurality of candidate network functions or the identification corresponding to the first node; wherein the second network function is configured to establish the PDU session.

2. The method according to claim 1, wherein said determining a second network function in the second node based on the information of the plurality of candidate network functions comprises:

the second network function is determined among the plurality of candidate network functions based on information of the plurality of candidate network functions, the plurality of candidate network functions being network functions in the second node.

3. The method for establishing a protocol data unit PDU session according to claim 1, wherein determining a second network function in the second node based on the identification corresponding to the first node comprises:

acquiring target data network access identifier DNAI information from the third network function; wherein, the data network indicated by the target DNAI information is the data network corresponding to the PDU session;

And determining the second network function in the second node according to the target DNAI information.

4. A method of establishing a protocol data unit, PDU, session according to claim 3, wherein the identification corresponding to the first node comprises one or more of:

A unit identity of the first node;

and the identification of the third network function.

5. The method for establishing a protocol data unit, PDU, session according to any of claims 1 to 4, wherein the information of the plurality of candidate network functions is carried in any of the following messages:

PDU session release message;

PDU session modification message.

6. The method according to any one of claims 1 to 4, wherein the identifier corresponding to the first node is carried in a PDU session establishment request.

7. The method for establishing a protocol data unit, PDU, session according to any of claims 1 to 4, wherein the first network function comprises one or more of the following:

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

8. A method for establishing a protocol data unit PDU session, applied to a terminal, the method comprising:

And sending the information of the candidate network functions or the identification corresponding to the first node to the first network function in the second node.

9. The method of claim 8, wherein the information of the plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

10. The method according to claim 8, wherein the identifier corresponding to the first node is carried in a PDU session establishment request.

11. A first communication device, the first communication device having a first network function, the first communication device comprising: memory, transceiver, processor;

the memory is used for storing a computer program;

the transceiver is used for receiving and transmitting data under the control of the processor;

The processor is configured to read the computer program in the memory and perform the following operations:

determining a second network function in the second node based on information of a plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is for establishment of a PDU session.

12. The first communication device of claim 11, wherein the processor is specifically configured to:

13. The first communication device of claim 12, wherein the processor is specifically configured to:

14. The first communication device of claim 13, wherein the identification corresponding to the first node comprises one or more of:

A unit identity of the first node;

and the identification of the third network function.

15. The first communication device according to any of claims 12 to 14, wherein the information of the plurality of candidate network functions is carried in any of the following messages:

PDU session release message;

PDU session modification message.

16. The first communication device according to any of the claims 12 to 14, wherein the identification corresponding to the first node is carried in a PDU session establishment request.

17. The first communication device of any of claims 12 to 14, wherein the first network function comprises one or more of:

An access and mobility management function AMF;

Unified data management, UDM;

Policy control function PCF.

18. A terminal, comprising: memory, transceiver, processor;

the memory is used for storing a computer program;

19. The terminal of claim 18, wherein the information of the plurality of candidate network functions is carried in any one of the following messages:

PDU session release message;

PDU session modification message.

20. The terminal of claim 18, wherein the identity corresponding to the first node is carried in a PDU session establishment request.

21. An apparatus for establishing a protocol data unit, PDU, session, for use with a first network function, the apparatus comprising:

A determining module, configured to determine a second network function in the second node based on information of a plurality of candidate network functions or identifiers corresponding to the first node; wherein the second network function is configured to establish the PDU session.

22. An apparatus for establishing a protocol data unit PDU session, applied to a terminal, comprising:

the receiving module is used for receiving information of a plurality of candidate network functions transmitted by a third network function in a first node or identifiers corresponding to the first node;

And the sending module is used for sending the information of the candidate network functions or the identification corresponding to the first node to the first network function in the second node.

23. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program which, when executed by a processor, implements a method of establishing a protocol data unit PDU session according to any one of claims 1 to 7 or 8 to 10.