WO2019137547A1 - Session establishment method and device - Google Patents

Abstract

Embodiments of the present application provide a session establishment method and device, so that, when a terminal switches multiple PDU sessions having the same data network name (DNN) established in 5G to PDN connections in 4G, each PDU session can be anchored to the same control plane functional network element when being switched to 4G, and each PDN connection after switch has different access point names (APNs) so as to control an APN AMBR. The method comprises: a terminal sends a first request message of establishing a PDU session, the first request message comprising a DNN; the terminal receives a first response message, the first response message comprising an APN; the terminal sends a second request message of establishing a PDU connection to a mobile management network element, the second request message comprising the APN.

Description

Session establishment method and device

This application claims priority to Chinese Patent Application No. 201810037102.9, entitled "Conversation Establishment Method and Equipment", filed on January 15, 2018, the entire contents of which are incorporated herein by reference. .

Technical field

The present application relates to the field of communications technologies, and in particular, to a session establishment method and device.

Background technique

With the rapid development of wireless communication technology, the fifth generation (Fifth Generation, 5G) mobile communication technology came into being. In the initial stage of network deployment, the coverage of the 5G network is insufficient. Therefore, when the location of the user equipment (User Equipment, UE) changes, the handover between the 5G network and the fourth generation (4G) network may occur.

Establishing a packet data network (PDN) connection in a 4G network requires an access point name (APN) parameter, and a data network is required to create a protocol data unit (PDU) session in 5G. Name (data network name, DNN) and single network slice selection assistance information (S-NSSAI). In existing standard protocols, APN is equivalent to DNN.

During the research, the applicant found that in the prior art, when the PDU session established by the UE in the 5G is switched to the PDN connection in the 4G, the following problems may occur:

The UE may have multiple PDU sessions established in 5G, and these PDU sessions may use the same DNN. And 5G does not specify that the same DNN session must select the same session management device, therefore, these multiple PDU sessions with the same DNN may be anchored on different session management devices.

However, in 4G, in order to control the Aggregated Maximum Bit Rate (AMBR) of an APN, multiple PDN connections of the same APN are required to be anchored to only one session management device. If multiple PDU sessions with the same DNN in 5G are switched to multiple PDN connections with the same APN in 4G, if the session continuity is satisfied, the APN AMBR in 4G cannot be controlled.

Summary of the invention

The embodiment of the present application provides a session establishment method, device, and system, so that when a terminal establishes a PDN connection in which a PDU session with the same DNN is switched to a 4G network in a 5G network, the PDU session is guaranteed to be switched to 4G. It can be anchored to the same control plane function network element as the PDU session, and it is ensured that each PDN connection after the handover has a different APN, thereby enabling control of the APN AMBR.

To achieve the above objective, the embodiment of the present application provides the following technical solutions:

In a first aspect, a method for establishing a session is provided, the method comprising: a terminal sending a first request message for establishing a packet data unit PDU session, wherein the first request message includes a data network name DNN; and the terminal receives the first response a message, the first response message includes an access point name APN corresponding to the PDU session; the APN is unique within the range of the terminal, and is used to uniquely identify the PDU session of the terminal; The mobility management network element sends a second request message to establish a packet data network PDN connection, the second request message including the APN. Based on the session establishment method provided by the embodiment of the present application, in the process of establishing a PDU session, the terminal obtains an APN unique in its own range from the network side. That is to say, based on the scheme, when the terminal establishes multiple PDU sessions with the same DNN, the PDU sessions can be switched to PDN connections with different APNs, and the APNs corresponding to the switched PDN connections are different, so Problems that cannot be controlled by APN AMBR in the technology can also be solved.

In one possible design, the APN is carried in a protocol configuration item PCO. That is to say, the control plane function network element on the network side can send the APN to the terminal through the PCO message, so that other intermediate devices in the network can avoid parsing the information (for example, the MME in the 4G network), thereby minimizing The solution leads to an update of the devices in the network.

In a possible design, the first request message further includes a PDU session identifier of the PDU session, the first response message further includes the PDU session identifier, and the sending is established to the mobility management network element. Before the second request message of the PDN connection, the method further comprises: saving the APN in a session context indicated by the PDU session identifier.

In a possible design, the method further includes: sending indication information, where the indication information is used to indicate that all PDU sessions established by the terminal or a specific PDU session needs to be subsequently switched to the 4G network. The indication information may be sent to the SMF+PGW-C by the terminal or the third-party application server during the session establishment process. When the terminal requests the established PDU session to satisfy the indication information, the process of the solution of the present application is executed; otherwise, The prior art performs a process of establishing a PDU session. For example, the indication information may include at least one of an identifier of the terminal, a session corresponding to the PDU session, and a session and service continuity (SSC) mode, and an S-NSSAI corresponding to the PDU session. Or the indication information may also be sent to the SMF+PGW-C by the PDU session establishment request carried by the terminal. At this time, the indication information may be, for example, an indication bit. When the indication bit is set to bit “1”, it indicates that the PDU session requested to be established needs to be subsequently switched to the 4G network; when the indication bit is set to “0” or not When the indicator bit exists, it indicates that the PDU session requested to be established does not need to be switched to the 4G network.

In a possible design, the second request message is used to request to establish a PDN connection, and may specifically be an attach request or a PDN connection setup request.

A second aspect provides a session establishment method, the method comprising: a control plane function network element receiving a first request message from a terminal for requesting establishment of a packet data unit PDU session; wherein the first request message includes a data network The name DNN is obtained. The access point name APN corresponding to the PDU session is obtained, where the APN is unique within the range of the terminal, and is used to uniquely identify the PDU session of the terminal. Based on the session establishment method provided by the embodiment of the present application, in the process of establishing a PDU session, the terminal obtains an APN unique in its own range from the network side. That is to say, based on the scheme, when the terminal establishes multiple PDU sessions with the same DNN, the PDU sessions can be switched to PDN connections with different APNs, and the APNs corresponding to the switched PDN connections are different, so Problems that cannot be controlled by APN AMBR in the technology can also be solved.

In a possible design, the method further includes: sending a first response message to the terminal, where the first response message includes the APN. After the control plane function network element obtains the APN, the APN may be sent to the terminal through the PCO message in the PDU session establishment response, so that the terminal saves the APN in the session context.

In one possible design, the APN may be modified by the DNN that is uniquely parameterized within the range of the terminal. For example, the control plane function network element may modify the DNN according to one or more of the S-NSSAI, the PDU session ID, the identifier of the control plane function network element itself, and the random number in the PDU session establishment request, thereby dynamically generating the APN. In particular, the advantage of using random numbers for decoration is that it can hide network sensitive information. In order to ensure the uniqueness of random numbers, S-NSSAI, PDU session ID, SMF+PGW-C ID, and other uniques can be generated when generating random numbers. Sexual parameters such as time parameters are used as inputs to the random number generation function. After the random number is generated, the control plane function network element can use the random number as a modification of the DNN. There is a method for APN modification in TS23.003, and the DNN can be modified by referring to the existing APN modification method. With the method described in this application, the DNN in the PDU session that the terminal requests to establish can be mapped to the APN that is unique within the terminal range. Therefore, when the terminal establishes a different PDU session with the same DNN, the parameters of the modified DNN are not The same, so the generated APN is not the same. This ensures that different PDU sessions of the same DNN have different APNs when switching to PDN connections in the 4G network.

In one possible design, the control plane function network element also obtains the subscription data of the APN. For example, the control plane function network element may generate the subscription data of the APN according to the subscription data of the DNN, and send the generated subscription data of the APN to the user data management network element, or the user data management network element may generate the APN according to the subscription data of the DNN. The contract data is sent to the control plane function network element.

In a third aspect, a method for establishing a session is provided, the method includes: receiving, by a user data management network element, a first message sent by a control plane function network element, where the first message includes a DNN; and acquiring an access point name corresponding to the PDU session An APN, wherein the APN is unique within the range of the terminal for uniquely identifying the PDU session.

In one possible design, the APN is determined by modifying the DNN by a parameter whose value is unique within the range of the terminal. For example, the first message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, where the acquiring an access point name APN corresponding to the PDU session includes: The data management network element modifies the DNN according to one or more of the S-NSSAI, the PDU session ID, the identifier of the control plane function network element itself, and the random number in the PDU session establishment request, to generate an APN. In particular, the advantage of using random numbers for decoration is that it can hide network sensitive information. In order to ensure the uniqueness of random numbers, S-NSSAI, PDU session ID, SMF+PGW-C ID, and other uniques can be generated when generating random numbers. Sexual parameters such as time parameters are used as inputs to the random number generation function. After generating the random number, the user data management network element can use the random number as a modification of the DNN. There is a method for APN modification in TS23.003, and the DNN can be modified by referring to the existing APN modification method. With the method described in this application, the DNN in the PDU session that the terminal requests to establish can be mapped to the APN that is unique within the terminal range. Therefore, when the terminal establishes a different PDU session with the same DNN, the parameters of the modified DNN are not The same, so the generated APN is not the same. This ensures that different PDU sessions of the same DNN have different APNs when switching to PDN connections in the 4G network.

In one possible design, the user data management network element obtains subscription data for the APN. For example, the user data management network element may generate the subscription data of the APN according to the subscription data of the DNN, or accept the subscription data of the APN from the control plane function network element, and send the APN subscription data to the mobility management network element (MME), so that The mobility management network element may authorize the establishment request of the corresponding PDN connection according to the subscription data of the APN. When the user data management network element generates the subscription data of the APN according to the subscription data of the DNN, the first message further includes an S-NSSAI, and the user data management network element acquires the PDU session corresponding according to the S-NSSAI and the DNN. DNN's signing data.

In a fourth aspect, a terminal is provided, the terminal having the function of implementing the method described in the first aspect above. This function can be implemented in hardware or in hardware by executing the corresponding software. The hardware or software includes one or more modules corresponding to the functions described above.

A fifth aspect provides a terminal, including: a processor and a memory; the memory is configured to store a computer execution instruction, and when the terminal is running, the processor executes the computer execution instruction stored in the memory to enable the terminal to execute A session establishing method as described in any one of the above first aspects.

In a sixth aspect, a computer readable storage medium is provided having stored therein instructions that, when executed on a computer, cause the computer to perform the session establishment described in any of the above first aspects method.

In a seventh aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the session establishment method of any of the above first aspects.

In an eighth aspect, a chip system is provided, the chip system comprising a processor for supporting a terminal to implement the functions involved in the above aspects. In one possible design, the chip system further includes a memory for storing necessary program instructions and data for the terminal. The chip system can be composed of chips, and can also include chips and other discrete devices.

For the technical effects brought by any one of the fourth aspect to the eighth aspect, refer to the technical effects brought by different design modes in the first aspect, and details are not described herein again.

In a ninth aspect, a control plane function network element is provided, the control plane function network element having the function of implementing the method described in the second aspect above. This function can be implemented in hardware or in hardware by executing the corresponding software. The hardware or software includes one or more modules corresponding to the functions described above.

A tenth aspect provides a control plane function network element, including: a processor and a memory; the memory is configured to store a computer execution instruction, and when the control plane function network element is running, the processor executes the computer stored in the memory Executing an instruction to cause the control plane function network element to perform the session establishment method as described in any of the above second aspects.

In an eleventh aspect, a computer readable storage medium is provided having stored therein instructions that, when run on a computer, cause the computer to perform the session of any of the above second aspects Establish a method.

According to a twelfth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the session establishment method of any of the above second aspects.

In a thirteenth aspect, a chip system is provided, the chip system comprising a processor for supporting a control plane function network element end to implement the functions involved in the above aspects. In one possible design, the chip system further includes a memory for storing program instructions and data necessary for the control plane function network element. The chip system can be composed of chips, and can also include chips and other discrete devices.

For the technical effects brought by the design mode of any one of the ninth to thirteenth aspects, refer to the technical effects brought by different design modes in the second aspect, and details are not described herein again.

In a fourteenth aspect, a user data management network element is provided, the user data management network element having the function of implementing the method described in the third aspect above. This function can be implemented in hardware or in hardware by executing the corresponding software. The hardware or software includes one or more modules corresponding to the functions described above.

According to a fifteenth aspect, a user data management network element includes: a processor and a memory; the memory is configured to store a computer execution instruction, and when the user data management network element is running, the processor executes the memory storage The computer executes the instructions to cause the user data management network element to perform the session establishment method as described in any of the above third aspects.

In a sixteenth aspect, a computer readable storage medium having stored therein instructions that, when run on a computer, cause the computer to perform the session of any of the above third aspects Establish a method.

In a seventeenth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the session establishment method of any of the above third aspects.

In an eighteenth aspect, a chip system is provided, the chip system including a processor for supporting a user data management network element to implement the functions involved in the above aspects. In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the second mobility management entity. The chip system can be composed of chips, and can also include chips and other discrete devices.

For the technical effects brought by any one of the fourteenth to eighteenth aspects, refer to the technical effects brought by different design modes in the third aspect, and details are not described herein again.

These and other aspects of the present application will be more readily apparent from the following description of the embodiments.

DRAWINGS

FIG. 1 is a schematic diagram of an existing 4G network and 5G network interworking architecture;

2 is a schematic structural diagram of hardware of a communication device according to an embodiment of the present application;

FIG. 3 is a schematic flowchart 1 of a session establishing method according to an embodiment of the present application;

FIG. 4 is a second schematic flowchart of a session establishing method according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of an apparatus according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a control plane function network element according to an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a user data management network element according to an embodiment of the present disclosure.

Detailed ways

In order to facilitate the understanding of the technical solutions of the embodiments of the present application, a brief introduction of the related art of the present application is first given as follows.

The embodiment of the present invention provides a method for mobility management, which can be applied to the 4G network and the 5G network interworking architecture system 100 shown in FIG. 1. As shown in FIG. 1, the user plane function is shared between the 4G network and the 5G network. (user plane function, UPF) entity + PDN gateway user plane function (PGW-U) entity, session management function (SMF) entity + PDN gateway control plane function (PDN gateway control plane function , PGW-C) entity, policy control function (PCF) entity + policy and charging rules function (PCRF) entity, home subscriber server (HSS) + unified data Unified data management (UDM) entity. Here, "+" means the setting, UPF is the user plane function of the 5G network, PGW-U is the gateway user plane function of the 4G network corresponding to the UPF, SMF is the session management function of the 5G network, and PGW-C is the corresponding to the SMF. The gateway control plane function in the 4G network, the PCF is the policy control function of the 5G network, and the PCRF is the policy charging rule function of the 4G network corresponding to the PCF. Here, "coupling" means that the same device has the functions of two entities at the same time. In the embodiment of the present application, for convenience of description, the HSS+UDM entity is referred to as a user data management network element, and the PGW-C entity + SMF entity is referred to as a control plane function network element, and is uniformly described herein. Narration. Certainly, the network device after the above-mentioned connection may also use other names, which is not specifically limited in this embodiment of the present application.

In addition, as shown in FIG. 1 , the foregoing 4G network and 5G network interworking architecture may further include a Mobility Management Entity (MME) and a Serving Gateway (SGW), and access and movement in the 5G network. Access and Mobility Management Function (AMF) entity.

The terminal accesses the 4G network through an evolved universal terrestrial radio access network (E-UTRAN) device, and the terminal passes the next generation radio access network (NG-RAN) device. Access to 5G networks. The E-UTRAN device communicates with the MME through the S1-MME interface, the E-UTRAN device communicates with the SGW through the S1-U interface, the MME communicates with the SGW through the S11 interface, and the MME communicates with the user data management entity through the S6a interface, and the MME passes the N26 interface. AMF entity communication, the SGW communicates with the PGW-U entity + UPF entity through the S5-U interface, the SGW communicates with the PGW-C entity + SMF entity through the S5-C interface, and the PGW-U entity + UPF entity passes the N3 interface and the NG-RAN Device communication, the PGW-U entity + UPF entity communicates with the PGW-C entity + SMF entity through the N4 interface, the PGW-C entity + SMF entity communicates with the PCRF entity + PCF entity through the N7 interface, and the HSS+UDM entity passes the N10 interface and the PGW -C entity + SMF entity communication, HSS+UDM entity communicates with AMF entity through N8 interface, PCRF entity + PCF entity communicates with AMF entity through N15 interface, PGW-C entity + SMF entity communicates with AMF entity through N11 interface, AMF entity The NMF entity communicates with the NG-RAN device through the N2 interface, and the AMF entity communicates with the terminal through the N1 interface. The N26 interface between the MME and the AMF may not exist in some scenarios in the foregoing interworking architecture. The N26 interface may be used for terminal context transfer and handover procedures. This application will describe whether there is an N26 interface between the MME and the AMF, respectively describing the possible implementations.

It should be noted that the name of the interface between the network elements in FIG. 1 is only an example. In the specific implementation, the interface name may be other names, which is not specifically limited in this embodiment of the present application.

It should be noted that the NG-RAN device in the 5G network may also be referred to as an access device, and the access device refers to a device that accesses the core network, for example, a base station, a broadband network service gateway (broadband network gateway, BNG), aggregation switch, non-3GPP access equipment, etc. The base station may include various types of base stations, such as a macro base station, a micro base station (also referred to as a small station), a relay station, an access point, and the like, which are not specifically limited in this embodiment of the present application.

Of course, there may be other network elements in the 4G network and the 5G network. For example, the 4G network may also include a general packet radio system (GPRS) service support node (SGSN), etc., 5G. The network may also include an authentication service function (AUSF) entity and a network slice selection function (NSSF) entity, which are not specifically limited in this embodiment of the present application.

The terminals involved in the embodiments of the present application may include various handheld devices having wireless communication functions, in-vehicle devices, wearable devices, computing devices, or other processing devices connected to the wireless modem; and may also include a subscriber unit ( Subscriber unit), cellular phone, smart phone, wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem (modem), handheld device, a laptop computer, a cordless phone, or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, a user equipment (UE), Mobile station (MS), terminal device, etc. For convenience of description, in the present application, the above mentioned devices are collectively referred to as terminals.

APN:

In a 4G network, the terminal may provide an APN to the MME when initiating a packet service. According to the APN provided by the terminal, the MME can perform domain name resolution by using a domain name server (DNS) to obtain an address of the session management network element (for example, an Internet Protocol address), thereby accessing the terminal to the PDN corresponding to the APN. in.

DNN:

In a 5G network, the terminal may provide the S-NSSAI and the DNN to the AMF when initiating the establishment of the PDU session. The AMF determines the address of the session management network element based on the S-NSSAI, DNN, and other information (such as the subscription information of the terminal and the local carrier policy, etc.). The determined session management network element establishes a PDU session for the terminal based on the S-NSSAI and the DNN.

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. In the description of the present application, "a plurality" means two or more than two unless otherwise stated. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", and the like are used to distinguish the same items or similar items whose functions and functions are substantially the same. Those skilled in the art can understand that the words "first", "second" and the like do not limit the number and execution order, and the words "first", "second" and the like are not necessarily limited.

The network architecture and the service scenario described in the embodiments of the present application are for the purpose of more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation of the technical solutions provided by the embodiments of the present application. The technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

As shown in FIG. 2, the node shown in FIG. 1, such as a terminal, MME, AMF, SMF entity + PGW-C entity, E-UTRAN or NG-RAN, may be the communication device (or system) in FIG. The way to achieve.

FIG. 2 is a schematic diagram showing the hardware structure of a communication device according to an embodiment of the present application. The communication device 200 includes at least one processor 201, a communication line 202, a memory 203, and at least one communication interface 204.

The processor 201 can be a general central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more for controlling the execution of the program of the present application. integrated circuit.

Communication line 202 can include a path for communicating information between the components described above.

The communication interface 204 uses devices such as any transceiver for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc. .

The memory 203 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type that can store information and instructions. The dynamic storage device can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, and a disc storage device. (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program code in the form of instructions or data structures and can be Any other media accessed, but not limited to this. The memory may be stand-alone and connected to the processor via communication line 202. The memory can also be integrated with the processor.

The memory 203 is used to store computer execution instructions for executing the solution of the present application, and is controlled by the processor 201 for execution. The processor 201 is configured to execute computer execution instructions stored in the memory 203, thereby implementing the session establishment method provided by the following embodiments of the present application.

Optionally, the computer-executed instructions in the embodiment of the present application may also be referred to as an application code, which is not specifically limited in this embodiment of the present application.

In a particular implementation, as an embodiment, processor 201 may include one or more CPUs, such as CPU0 and CPU1 in FIG.

In a particular implementation, as an embodiment, communication device 200 can include multiple processors, such as processor 201 and processor 208 in FIG. Each of these processors can be a single-CPU processor or a multi-core processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data, such as computer program instructions.

In a particular implementation, as an embodiment, the communication device 200 can also include an output device 205 and an input device 206. Output device 205 is in communication with processor 201 and can display information in a variety of ways. For example, the output device 205 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. Wait. Input device 306 is in communication with processor 301 and can receive user input in a variety of ways. For example, input device 206 can be a mouse, keyboard, touch screen device or sensing device, and the like.

The communication device 200 described above may be a general purpose device or a dedicated device. In a specific implementation, the communication device 200 can be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or the like in FIG. device. The embodiment of the present application does not limit the type of the communication device 200.

The session establishment method provided by the embodiment of the present application will be specifically described below with reference to FIG. 1 and FIG.

As shown in FIG. 3, a session establishment method provided by an embodiment of the present application is provided. In this embodiment, the terminal first establishes a PDU session in the 5G network, and the terminal needs to access the 4G network because the terminal location moves out of the 5G service range or other reasons. Specifically, when the terminal requests to establish a PDU session, the control plane function network element or the user data management network element maps the DNN carried in the PDU session establishment request to an APN unique to the terminal, and maintains the mapped APN. In the context of the terminal. In addition, the control plane function network element needs to send the mapped APN to the terminal (for example, the mapped APN may be carried in a protocol configuration option (PCO) message and sent to the terminal). When the terminal needs to switch from 5G to 4G, the APN is carried, and then the MME obtains the context of the terminal from the user data management network element, and determines the control plane function for the terminal according to the carried APN and the acquired context. The network element is configured to be anchored to the same control plane function network element as the original PDU session when the 5G PDU session is switched to 4G. When the terminal establishes a plurality of PDU sessions with the same DNN in the 5G network, the above method can be used to ensure that when switching to the 4G network, each PDU session can be anchored to the same as the original PDU session when switching to 4G. On the control plane function network element, it is ensured that each PDN connection after the handover has a different APN, thereby enabling control of the APN AMBR. Specifically, the following may include:

Step 301: The terminal sends a PDU session establishment request to the mobility management network element in the first network.

The mobility management network element in the first network may be, for example, the AMF shown in FIG. 3, and the mobile management network element in the first network is replaced by AMF. The PDU session establishment request includes an S-NSSAI, a DNN, and a PDU Session ID (PDU Session ID), and the PDU session establishment request is used to request the network side to use the network slice instance indicated by the S-NSSAI in the data network indicated by the terminal and the DNN. Establish a PDU session.

It should be noted that the terminal may establish multiple PDU sessions in the 5G network, and the multiple PDU sessions may correspond to the same DNN, and the same or different control plane function network elements (ie, the SMF+PGW in this embodiment) -C) Service, which is not limited by the embodiment of the present application. For convenience of description, the embodiment of the present application is only an example in which a terminal establishes a PDU session through a control plane function network element.

Step 302: The AMF accepts the PDU session establishment request sent by the terminal, and sends a session establishment request to the SMF+PGW-C.

The session establishment request includes the S-NSSAI, the DNN, and the PDU Session ID carried in the PDU session establishment request.

It should be noted that the AMF determines the address of the SMF+PGW-C as the prior art, which is not limited in the embodiment of the present invention, and the related method may refer to the existing standard.

In step 303, the SMF+PGW-C performs a mapping operation.

The mapping operation performed by the SMF+PGW-C includes mapping the DNN in the session establishment request to an APN unique to the terminal, and optionally, generating the subscription data corresponding to the APN. A method for generating the subscription data corresponding to the APN is to map the QoS parameter corresponding to the PDU session to the QoS parameter corresponding to the PDN connection corresponding to the 4G corresponding to the PDU session, such as mapping the session AMBR corresponding to the PDU session to the PDN connection. The APN AMBR maps the ARP corresponding to the PDU session to the ARP corresponding to the PDN connection, and saves the mapped QoS parameters as the signed APN subscription data in the HSS+UDM, so that when the terminal switches from 5G to 4G, the HSS +UDM sends the mapped APN subscription data to the corresponding MME. Alternatively, the DNN subscription data is directly mapped to the corresponding APN subscription data, and the mapped APN subscription data is saved in the HSS+UDM, so that when the terminal switches from 5G to 4G, the HSS+UDM sends the mapped APN subscription data. Give the corresponding MME.

The method in which the SMF+PGW-C maps the DNN in the session establishment request to the APN unique to the terminal may include multiple methods, for example:

(1) The SMF+PGW-C may map the DNN to an APN unique to the terminal according to the mapping relationship according to the mapping relationship between the locally pre-configured DNN and the APN. For example, SMF+PGW-C can pre-configure the mapping relationship between DNN, S-NSSAI and APN (as shown in Table 1) or the mapping relationship between DNN, S-NSSAI, SMF+PGW-C ID and APN (Table 2). Shown).

Table 1

DNN	S-NSSAI	APN
DNN1	S-NSSAI1	APN1

DNN1	S-NSSAI2	APN2
DNN2	S-NSSAI1	APN3
DNN2	S-NSSAI2	APN4

Table 2

DNN	S-NSSAI	SMF+PGW-C ID	APN
DNN1	S-NSSAI1	SMF+PGW-C 1	APN1
DNN1	S-NSSAI1	SMF+PGW-C 2	APN2
DNN2	S-NSSAI1	SMF+PGW-C 1	APN3
DNN2	S-NSSAI1	SMF+PGW-C 2	APN4

In a possible implementation manner, when a UE establishes only one PDU session in a network slice instance corresponding to an S-NSSAI for a DNN, the mapping relationship shown in Table 1 may be used to map the DNN to The terminal is the only APN. When the UE establishes multiple PDU sessions of the same DNN in one or more network slices corresponding to one S-NSSAI, the mapping relationship of Table 2 can be used to map the DNN to an APN unique to the terminal. .

It should be noted that the mapping relationship between Table 1 and Table 2 is only an example, and may be implemented by other mapping relationships, which is not limited by the embodiment of the present invention.

(2) The SMF+PGW-C may map the DNN to an APN unique to the terminal according to a preset rule. For example, the DNN can be modified to generate an APN using parameters that are unique relative to the terminal. A possible implementation manner is: the SMF+PGW-C modifies the DNN according to one or more of the S-NSSAI, the PDU session ID, the SMF+PGW-C's own identifier, and the random number in the PDU session establishment request. Thus, the APN is dynamically generated, for example: DNN@PDU session ID1=APN1, DNN@PDU session ID2=APN2, DNN@PDU session ID3=APN3. The advantage of using random numbers for decoration is that you can hide network sensitive information such as SMF+PGW-C ID. SMF+PGW-C first generates a random number. In order to ensure the uniqueness of the random number, S-NSSAI, PDU session ID, SMF+PGW-C ID, and other unique parameters such as time parameters can be generated when generating random numbers. As an input to the random number generation function. There are many methods in the prior art to ensure the uniqueness of the random number, which is not specified in the embodiment of the present invention. After generating the random number, SMF+PGW-C can use the random number as the modification of DNN. For example, DNN=internet, random number=1234, DNN can be modified to internet.1234, or internet@1234. There is a method for APN modification in TS23.003, and the DNN can be modified by referring to the existing APN modification method. In addition, it should be noted that the APN generated by the mapping may also be independent of the DNN. For example, the SMF+PGW-C may generate a random according to the PDU session ID and other unique parameters such as time parameters. The number is used as the mapped APN.

In some scenarios, the method of (1)(2) above ensures that the APN generated by the mapping is not repeated in all PDU sessions established by the terminal. It should be noted that the two methods (1) and (2) may also be combined in a specific implementation to implement mapping the DNN to an APN unique to the terminal. For example, SMF+PGW-C can determine a temporary APN according to Table 1, and then modify the temporary APN with its own SMF+PGW-C ID to obtain the mapped APN.

On the other hand, the SMF+PGW-C can also map the QoS parameters corresponding to the PDU session to the QoS parameters corresponding to the PDN connection after the session is switched to the 4G, such as mapping the session AMBR to the APN AMBR corresponding to the PDN connection, and the PDU. The allocation retention priority (ARP) of the session is mapped to the ARP of the PDN connection. One way to map a Session AMBR to an APN AMBR is to set the APN AMBR equal to the Session AMBR. There may be other mapping methods in the specific implementation, such as setting the APN AMBR to be smaller than the Session AMBR, which is not specified in the embodiment of the present invention. Similarly, a method of mapping the ARP corresponding to the PDU session to the ARP corresponding to the PDN connection is to set the ARP corresponding to the PDN connection to the ARP corresponding to the PDU session. In the specific implementation, there may be other mapping methods, for example, connecting the PDN. The corresponding ARP is set to be greater than or less than the ARP corresponding to the PDU session, which is not specified in the embodiment of the present invention.

Specifically, the SMF+PGW-C also associates the mapped APN and the QoS parameter corresponding to the mapped PDN connection (optional) in the context of the terminal.

The method further includes the SMF+PGW-C returning a session establishment response to the AMF, the session establishment response including information (such as an identifier or an address, etc.) of the control plane function network element.

In step 304, the SMF+PGW-C sends a registration request to the HSS+UDM.

The registration request includes information of the SMF+PGW-C (for example, SMF+PGW-C ID or address information, etc.) and the mapped APN, so that the HSS+UDM can display the information of the SMF+PGW-C and the mapped APN. The association is saved to the relevant information of the terminal (such as the session context). If the SMF+PGW-C generates the subscription data of the APN, the subscription request message further includes the subscription data of the APN, so that the HSS+UDM saves the subscription data of the APN to the related information of the terminal (for example, the terminal corresponds to In the contract data or session context, etc.). It should be noted that the embodiment of the present application does not limit how the HSS+UDM saves related information.

It should be noted that the mapping of the DNN to the APN performed by the SMF+PGW-C and the mapping of the QoS parameters corresponding to the PDU session to the QoS parameters corresponding to the PDN connection may also be performed by the HSS+UDM. Specifically, when the SMF+PGW-C performs the above mapping operation performed by the HSS+UDM, step 303 and step 304 may be replaced by the following steps A to C:

Step A, SMF+PGW-C sends a registration request to HSS+UDM;

The registration request includes information such as the identifier of the terminal, the information of the SMF+PGW-C, the DNN in the session establishment request received in step 302, and the optional S-NSSAI.

Step B: The HSS+UDM receives the registration request sent by the SMF+PGW-C, and performs a mapping operation.

The method for performing mapping operation by the HSS+UDM is the same as the method for performing mapping with the SMF+PGW-C in step 303. For the specific process, refer to the related description in step 303. The difference from step 303 is that the HSS+UDM obtains the subscription data of the APN. The HSS+UDM first obtains the subscription data of the DNN corresponding to the session according to the S-NSSAI and the DNN corresponding to the PDU session, and then maps the relevant parameters in the subscription data of the corresponding DNN to the relevant parameters in the APN subscription data, and the DNN The contract data includes APN AMBR, ARP, and the like.

After performing the mapping operation, the HSS+UDM saves the information of the SMF+PGW-C, the mapped APN, and the subscription data corresponding to the mapped APN to the related information of the terminal, for example, the SMF+PGW-C The information and the mapped APN are saved in the session context of the terminal, and the subscription data corresponding to the mapped APN is saved in the subscription data of the UE.

Step C, HSS+UDM sends a registration response to SMF+PGW-C.

The registration response includes the mapped APN and the signed APN subscription data. After receiving the registration response sent by the HSS+UDM, the SMF+PGW-C saves the mapped APN and the mapped APN subscription association to the registration association. The relevant information of the terminal.

It should be noted that the above mapping may also be performed separately in SMF+PGW-C and HSS+UDM. For example, SMF+PGW-C is responsible for mapping DNN to APN, and HSS+UDM is responsible for generating subscription data of APN. The embodiments of the present invention do not make provisions.

Optionally, the SMF+PGW-C or the HSS+UDM receives the indication information from the terminal or the third-party application server, where the indication information is used to indicate all PDU sessions established by the terminal or a specific PDU session. Need to switch to 4G network.

A possible implementation manner is that the indication information may be sent by the terminal or the third-party application server to the SMF+PGW-C during the session establishment process. When the terminal requests the established PDU session in step 301, the indication information is met. The process of the embodiment of the present application is performed; otherwise, the process of establishing a PDU session is performed according to the prior art. For example, the indication information may include at least one of an identifier of the terminal, a session corresponding to the PDU session, and a session and service continuity (SSC) mode, and an S-NSSAI corresponding to the PDU session. For example, when the terminal that the SMF+PGW-C receives the identity indication of the terminal requests to establish a PDU session to the data network indicated by the DNN, the SMF+PGW-C determines that the PDU session needs to be subsequently switched to the 4G network, or when the SMF When the PGW-C determines that the session of the established PDU is SSC mode 1, the SMF+PGW-C may determine, according to the information, that the PDU session needs to be subsequently switched to the 4G network, or the SMF+PGW-C according to the S corresponding to the session. - NSSAI determines that the PDU session needs to be subsequently switched to the 4G network. Alternatively, the indication information may also be sent by the terminal to the SMF+PGW-C in the PDU session establishment request in step 301. At this time, the indication information may be, for example, an indication bit. When the indication bit is set to bit “1”, it indicates that the PDU session requested to be established needs to be subsequently switched to the 4G network; when the indication bit is set to “0” or not When the indicator bit exists, it indicates that the PDU session requested to be established does not need to be switched to the 4G network.

Step 305: A subsequent PDU session establishment process.

In step 302, the SMF+PGW-C receives the session establishment request sent by the terminal from the AMF, and establishes a PDU session for the terminal based on the S-NSSAI and the DNN in the session establishment request. The process of establishing a PDU session may refer to an existing process, and details are not described herein.

Steps 301 to 305 are used to implement the process of establishing a PDU session in the terminal in the 5G network. In this process, the embodiment of the present application adds that the DNN in the PDU session is mapped to the APN in which the terminal range name does not overlap.

Step 306: The SMF+PGW-C sends the mapped APN to the terminal.

Specifically, the SMF+PGW-C can carry the mapped APN in the PCO message and send it to the terminal. One possible implementation is that the PCO message can be carried in a PDU session setup response. The PCO message is used to send the mapped APN to the terminal, which can avoid the extra burden caused by the SMF+PGW-C and the network element in the middle of the terminal parsing the cell during the message delivery.

After receiving the mapped APN, the terminal stores the mapped APN in the session context. Specifically, in step 306, the SMF+PGW-C sends the PDU Session ID to the terminal together, and after receiving the mapped APN and the PDU Session ID, the terminal stores the mapped APN in the corresponding session context.

Step 307: The terminal sends an attach request or a PDN connection setup request to the MME, so that the MME receives the attach request or the PDN connection establishment request.

The mapping request or the PDN connection establishment request carries the mapped APN received in step 306, and the mapped APN is also generated by mapping the terminal in the PDU session establishment process. It should be noted that the scenario in which the terminal sends a PDN connection establishment request in this step may be that the UE has completed the attach procedure, but still needs to switch the PDU session, and initiates a corresponding PDN connection establishment process for the PDU session immediately after the attach procedure is completed. .

Specifically, step 307 may occur when the location of the terminal moves, for example, from 5G coverage to only 4G coverage, or for some other reasons, the terminal changes from 5G network access data network to 4G network connection. When entering the data network.

Further, when the request is an attach in step 307, the attach request further includes an identifier of the terminal. When it is to be noted, the identifier of the terminal herein may be information for characterizing the user equipment, such as an International Mobile Subscriber Identity (IMSI), or may be a temporary identifier of the UE, such as globally unique from 5G. 4G GUTI mapped by globally unique temporary identity (GUTI). The specific form of the identifier of the terminal is not limited in this embodiment of the present application.

When the request is attached in step 307, step 308 is performed to obtain the related information of the terminal from the HSS+UDM. If the PDN connection establishment request is in step 307, it can be understood that the MME has already performed the attach procedure before the PDN connection establishment request. The related information of the terminal is obtained from the HSS+UDM, so step 309 is directly executed.

Step 308: Acquire relevant information of the terminal from the HSS+UDM.

Specifically, the terminal sends a location update request to the HSS+UDM, where the location update request carries the identifier of the terminal. The HSS+UDM obtains the context of the terminal according to the identifier of the terminal, for example, information including SMF+PGW-C, mapped APN, and signed data of the mapped APN. It should be noted that the context of the foregoing terminal may be stored in association. For example, multiple session information and corresponding subscription data may be saved in the context of the terminal. A possible implementation manner is shown in Table 3:

The contract data of the terminal may be as shown in Table 4:

Terminal identification	Signed APN
UE 1	APN1
UE 1	APN 2
UE 2	APN 4

The UE is used to refer to the identifier of the terminal. It should be noted that the APN subscription data in the foregoing Table 3 may also be stored in the subscription data. In the embodiment of the present invention, the mapped APN, SMF+PGW-C The storage format of ID, APN subscription data, and signed APN information is not limited. After receiving the location update request of the MME, the HSS+UDM obtains the context corresponding to the terminal according to the terminal identifier. For example, the HSS+UDM receives the identifier of the terminal carried in the location update request of the MME as UE1, and the HSS+UDM acquires the session context and the subscription information related to the UE1, such as (APN1, SMF+PGW-C1, APN1 signed, APN1). Signing data), (APN2, SMF+PGW-C1, APN2 signed, APN2 signing data). The HSS+UDM sends the acquired UE1 related session context and subscription information to the MME.

Step 309: The MME sends a session update request to the SMF+PGW-C.

Specifically, the MME determines the identifier of the anchored SMF+PGW-C according to the mapped APN received from the terminal, and the session context and the subscription data of the terminal acquired from the HSS+UDM, and determines the SMF+PGW to the determined SMF+PGW. -C sends a session update request. The session update request includes the mapped APN received from the terminal.

If step 307 is an attach request, the MME selects a serving gateway (S-GW) according to the location of the UE. The MME sends a session update request to the anchored SMF+PGW-C via the S-GW. And the downlink update information corresponding to the session allocated by the S-GW is carried in the session update request. Optionally, the MME sends the QoS parameters, such as APN AMBR, in the APN subscription data acquired in step 308 to the anchored SMF+PGW-C. The anchored SMF+PGW-C obtains the user plane tunnel information corresponding to the session according to the received APN search terminal context, including the IP address of the PGW-U+UPF and the uplink tunnel information. The anchored SMF+PGW-C notifies the downlink tunnel information of the S-GW to the PGW-C+UPF corresponding to the session (this step is prior art and is not shown in the figure).

In a possible implementation manner, before the MME sends the session update request to the SMF+PGW-C, the MME further includes the MME determining whether the terminal has the right to update the session. When the MME determines that the mapped APN sent by the terminal is signed, the MME determines that the terminal has the right to update the session, and performs step 309 to send a session update request to the SMF+PGW-C. The MME determines, according to the subscription information returned by the HSS+UDM, that the mapped APN sent by the terminal is unsigned or the subscription information returned by the HSS+UDM does not include the mapped APN, the MME determines that the terminal does not have the session update permission, and the process ends. .

Step 310: The SMF+PGW-C returns a session establishment response to the MME.

The SMF+PGW-C sends the uplink tunnel information of the PGW-U+UPF corresponding to the session to the S-GW. And the S-GW returns a session establishment response to the MME, and sends the uplink tunnel information of the S-GW allocated by the S-GW to the MME.

Step 311, follow-up process.

After receiving the session establishment response sent by the SMF+PGW-C, the MME enters a subsequent process to complete the establishment of the PDN connection.

In a possible implementation, if the step 307 is an attach request, the MME processes the subsequent attach procedure, including notifying the base station to create an air interface resource for the session, establishing a tunnel between the base station and the S-GW, and notifying the terminal of the attach result. . If the step 307 is a PDN connection establishment request, the subsequent process is a PDN connection establishment process, which also includes notifying the base station to create an air interface resource for the session, establishing a tunnel between the base station and the S-GW, and notifying the result of the PDN connection establishment. terminal. For the subsequent process, reference may be made to the existing process, and details are not described herein.

Based on the session establishment method provided by the embodiment of the present application, in the process of establishing a PDU session by the terminal, the SMF+PGW-C or the HSS+UDM is required to generate a temporary APN unique to the terminal according to the DNN, and the subscription data corresponding to the DNN. The contract data corresponding to the mapped APN is generated, and the related information is saved in SMF+PGW-C or HSS+UDM. When the terminal establishes a PDN connection in which the PDU session with the same DNN is cut into the 4G network in the 5G network, the terminal can ensure that each PDU session can be anchored to the same control plane function network element when switching to 4G. Moreover, it is ensured that each PDN connection after the handover has a different APN, so that the control of the APN AMBR can be realized. In addition, the solution does not require changes to existing MMEs.

The actions of the control plane function network element (SMF+PGW-C) and the user data management network element (HSS+UDM) in the above steps 301 to 311 can be called by the processor 201 in the communication device 200 shown in FIG. The application code stored in 203 is executed, and the embodiment of the present application does not impose any limitation on this.

It should be noted that the embodiment described in FIG. 3 is applicable to a scenario where there is no N26 interface between the mobility management network element AMF in the first network and the mobility management network element MME in the second network, when between the AMF and the MME. When there is an N26 interface, the method as described in FIG. 4 can be employed. As shown in FIG. 4, a session establishment method provided by an embodiment of the present application includes the following steps:

Steps 401-406, the same as steps 301-306, specifically refer to the embodiment shown in FIG. 3, and details are not described herein again.

When the terminal is in the idle (IDLE) state, steps 407-411 are performed:

Step 407: The terminal sends a tracking area update request to a mobility management network element (such as an MME) of the second network.

The tracking area update request includes the 4G GUTI mapped by the 5G-GUTI, and the specific mapping method refers to the prior art. The MME can determine the AMF that was previously serving the terminal according to the 4G GUTI.

Step 408: The MME requests the context of the terminal from the AMF.

Step 409: After receiving the request sent by the MME, the AMF acquires the PDU session context from the control plane function network element.

The PDU session context includes information of the mapped APN and the corresponding control plane functional entity.

Step 410: The AMF sends the PDU session context to the MME.

Step 411: In the subsequent process, the MME performs session switching according to the context received from the AMF.

The subsequent process can refer to the existing process, and will not be described here.

When the terminal is in the Connected state, steps 412-415 are performed:

Step 412: The base station sends a handover request to the AMF.

When the base station determines that the terminal needs to switch to 4G, it sends an HO request to the AMF.

Step 413, the same step 409

Step 414: The AMF sends a Relocation Request to the MME, where the AMF sends the session context to the MME.

Step 415, follow-up process.

The subsequent handover procedure can be found in the related description in TS 23.502. In the handover procedure, the MME selects the SGW and notifies the PGW-C+SMF via the SGW to perform session update.

The session establishment method provided by the embodiment of the present application can ensure that when the terminal establishes a PDN connection in which a plurality of PDU sessions with the same DNN are switched to the 4G network in the 5G network, the PDU session is guaranteed to be switched to 4G. It can be anchored to the same control plane function network element as the PDU session, and it is ensured that each PDN connection after the handover has a different APN, thereby enabling control of the APN AMBR.

The actions of the control plane function network element and the user data management network element in the foregoing steps S401 to S415 can be performed by the processor 201 in the communication device 200 shown in FIG. 2 calling the application code stored in the memory 203. The embodiment does not impose any limitation on this.

The solution provided by the embodiment of the present application is mainly introduced from the perspective of interaction between the network elements. It can be understood that the foregoing terminal, the user data management network element, the control plane function network element, the AMF, and the MME, etc., in order to implement the above functions, include hardware structures and/or software modules corresponding to each function. Those skilled in the art will readily appreciate that the present application can be implemented in a combination of hardware or hardware and computer software in combination with the elements and algorithm steps of the various examples described in the embodiments disclosed herein. Whether a function is implemented in hardware or computer software to drive hardware depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

In the embodiment of the present application, the function module of the terminal, the user data management network element, and the control plane function network element may be divided according to the foregoing method. For example, each function module may be divided according to each function, or two or more functions may be used. The functions are integrated in one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of the module in the embodiment of the present application is schematic, and is only a logical function division, and the actual implementation may have another division manner.

For example, in the case of dividing each functional module in an integrated manner, FIG. 5 is a schematic structural view of the apparatus according to the above embodiment. The device 50 may be a terminal or a chip in the terminal, which is not specifically limited in this embodiment of the present application. As shown in FIG. 5, the device includes: a receiving module 501 and a sending module 502.

The sending module is configured to send a first request message for establishing a packet data unit PDU session, where the first request message includes a data network name DNN, and the receiving module 501 is configured to receive a first response message, where The first response message includes an access point name APN; wherein the APN is determined by the DNN and is unique within the terminal range; wherein the APN can be carried in a protocol configuration item PCO; the sending module 502. The method further includes sending, to the mobility management network element, a second request message for establishing a packet data network PDN connection, where the second request message includes the APN.

Optionally, the first request message further includes a PDU session identifier of the PDU session, where the first response message further includes the PDU session identifier; the terminal further includes:

The saving module 503 is configured to save the APN in a session context indicated by the PDU session identifier.

Optionally, the sending module is further configured to send indication information, where the indication information is used to indicate that all PDU sessions established by the terminal or a specific PDU session need to be subsequently switched to the 4G network.

Optionally, the second request message is an attach request or a PDN connection setup request.

All the related content of the steps involved in the foregoing method embodiments may be referred to the functional descriptions of the corresponding functional modules, and details are not described herein again.

In this embodiment, the terminal 50 can be presented in an integrated manner to divide the form of each functional module. A "module" herein may refer to an application-specific integrated circuit (ASIC), circuitry, a processor and memory that executes one or more software or firmware programs, integrated logic circuitry, and/or other functions that provide the functionality described above. Device. In a simple embodiment, those skilled in the art will appreciate that terminal 50 can take the form shown in FIG.

For example, the processor 201 in FIG. 2 can execute the instruction by calling the computer stored in the memory 203, so that the terminal 50 executes the session establishment method in the above method embodiment. Specifically, the function/implementation process of the receiving module 501, the sending module 502, and the saving module 503 in FIG. 5 can be implemented by the processor 201 in FIG. 2 calling a computer executing instruction stored in the memory 203.

Optionally, when the device 50 is a chip, the function/implementation process of the receiving module 501 and the sending module 502 can also be implemented by using a pin or a circuit. Alternatively, when the device 50 is a chip, the memory 203 may be a memory unit within the chip, such as a register, a cache, or the like. Of course, when the device 50 is a terminal, the memory 203 may be a storage unit located outside the chip in the terminal, which is not specifically limited in this embodiment of the present application.

The terminal provided by the embodiment of the present application can be used to perform the above-mentioned session establishment method. Therefore, the technical effects of the method can be referred to the foregoing method embodiments, and details are not described herein again.

For example, in the case of dividing each functional module in an integrated manner, FIG. 6 shows a schematic structural diagram of a control plane function network element 60. The control plane function network element 60 includes a receiving module 601 and an obtaining module 602. The receiving module 601 is configured to receive a first request message from the terminal for requesting to establish a packet data unit PDU session, where the first request message includes a data network name DNN, and the obtaining module 602 is configured to obtain An access point name APN corresponding to the PDU session, wherein the APN is determined by the DNN and is unique within the range of the terminal.

The network element further includes: a sending module 603. The sending module is configured to send a first response message to the terminal, where the first response message includes the APN. Optionally, the APN is carried in a protocol configuration item PCO.

Optionally, the APN is determined by modifying the DNN by a parameter whose value is unique within the terminal range.

Optionally, the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, where the obtaining module 602 is specifically configured to: according to the PDU session identifier And/or the S-NSSAI, and the DNN, generating the APN; the sending module is further configured to send, to the user data management network element, the APN, the DNN, and the control plane function network element information.

Optionally, the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, where the acquiring module is specifically configured to: identify the PDU session and / or the S-NSSAI, and the DNN is sent to the user data management network element; the APN is received from the user data management network element.

Optionally, the receiving module 601 is further configured to receive a session update request from a mobility management network element, where the session update request includes the APN.

Optionally, the receiving module is further configured to receive a request for acquiring the terminal session context sent by the mobility management network element, where the sending module is further configured to send a session context response to the mobility management network element, where The session context response includes information of the control plane function network element and the APN.

Optionally, the obtaining unit 602 is further configured to acquire subscription data of the APN. For example, the subscription data of the APN is generated according to the subscription data of the DNN, and the sending module 603 is further configured to send the subscription data of the APN to the user data management network element.

All the related content of the steps involved in the foregoing method embodiments may be referred to the functional descriptions of the corresponding functional modules, and details are not described herein again.

In this embodiment, the control plane function network element 60 is presented in a form that divides the various functional modules in an integrated manner. A "module" herein may refer to a particular ASIC, circuitry, processor and memory that executes one or more software or firmware programs, integrated logic circuitry, and/or other devices that provide the functionality described above. In a simple embodiment, those skilled in the art will appreciate that the control plane function network element 60 can take the form shown in FIG.

For example, the processor 201 in FIG. 2 can execute the instruction by calling the computer stored in the memory 203, so that the control plane function network element 60 executes the session establishment method in the above method embodiment. Specifically, the function/implementation process of the receiving module 601, the obtaining module 602, and the sending module 603 in FIG. 6 can be implemented by the processor 201 in FIG. 2 calling a computer executing instruction stored in the memory 203.

The control plane function network element provided by the embodiment of the present application can be used to perform the foregoing session establishment method. Therefore, the technical effects that can be obtained by reference to the foregoing method embodiments are not described herein.

For example, in the case of dividing each functional module in an integrated manner, FIG. 7 shows a schematic structural diagram of a user data management network element. The user data management network element 70 includes a receiving module 701 and an obtaining module 702. The receiving module 701 is configured to receive a first message of the control plane function network element, where the first message includes a data network name DNN, and the obtaining module 702 is configured to obtain the access corresponding to the PDU session. A point name APN, wherein the APN is determined by the DNN and is unique within the range of the terminal.

The APN is determined by modifying the DNN by a parameter whose value is unique within the range of the terminal. For example, the first message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, and the obtaining module 702 is specifically configured to use the S-NSSAI in the PDU session establishment request. One or more of the parameters of the PDU session ID, the identity of the control plane function network element, and the random number modify the DNN to generate an APN. In particular, the advantage of using random numbers for decoration is that it can hide network sensitive information. In order to ensure the uniqueness of random numbers, S-NSSAI, PDU session ID, SMF+PGW-C ID, and other uniques can be generated when generating random numbers. Sexual parameters such as time parameters are used as inputs to the random number generation function. After generating the random number, the user data management network element can use the random number as a modification of the DNN. There is a method for APN modification in TS23.003, and the DNN can be modified by referring to the existing APN modification method. With the method described in this application, the DNN in the PDU session that the terminal requests to establish can be mapped to the APN that is unique within the terminal range. Therefore, when the terminal establishes a different PDU session with the same DNN, the parameters of the modified DNN are not The same, so the generated APN is not the same. This ensures that different PDU sessions of the same DNN have different APNs when switching to PDN connections in the 4G network.

All the related content of the steps involved in the foregoing method embodiments may be referred to the functional descriptions of the corresponding functional modules, and details are not described herein again.

Optionally, the embodiment of the present application provides a chip system, where the chip system includes a processor, and is configured to support the terminal to implement the foregoing session establishment method. In one possible design, the chip system also includes a memory. This memory is used to store the necessary program instructions and data for the terminal. The chip system may be composed of a chip, and may also include a chip and other discrete devices. This embodiment of the present application does not specifically limit this.

Optionally, the embodiment of the present application provides a chip system, where the chip system includes a processor, and is configured to support a control plane function network element to implement the foregoing session establishment method. In one possible design, the chip system also includes a memory. The memory is used to store program instructions and data necessary for the control plane function network element. The chip system may be composed of a chip, and may also include a chip and other discrete devices. This embodiment of the present application does not specifically limit this.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present application are generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be from a website site, computer, server or data center Transmission to another website site, computer, server or data center via wired (eg coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg infrared, wireless, microwave, etc.). The computer readable storage medium can be any available media that can be accessed by a computer or a data storage device that includes one or more servers, data centers, etc. that can be integrated with the media. The usable medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (such as a solid state disk (SSD)) or the like.

Although the present application has been described herein in connection with the various embodiments, those skilled in the art can Other variations of the disclosed embodiments are achieved. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill several of the functions recited in the claims. Certain measures are recited in mutually different dependent claims, but this does not mean that the measures are not combined to produce a good effect.

While the present invention has been described in connection with the specific embodiments and embodiments thereof, various modifications and combinations can be made without departing from the spirit and scope of the application. Accordingly, the description and drawings are to be regarded as It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit and scope of the application. Thus, it is intended that the present invention cover the modifications and variations of the present invention.

Claims (35)

1. A session establishing method, the method comprising:

   The terminal sends a first request message for establishing a packet data unit PDU session, where the first request message includes a data network name DNN;

   Receiving, by the terminal, a first response message, where the first response message includes an access point name APN corresponding to the PDU session, where the APN is unique within the terminal range;

   The terminal sends a second request message for establishing a packet data network PDN connection to the mobility management network element, where the second request message includes the APN.
2. The method of claim 1 wherein the APN is carried in a protocol configuration item PCO.
3. The method according to claim 1 or 2, wherein the first request message further includes a PDU session identifier of the PDU session, and the first response message further includes the PDU session identifier; Before the second request message for establishing a PDN connection is sent to the mobility management network element, the method further includes:

   The APN is saved in a session context indicated by the PDU session identifier.
4. The method according to any one of claims 1-3, wherein the method further comprises:

   The indication information is sent to indicate that all PDU sessions established by the terminal or a specific PDU session need to be subsequently switched to the 4G network.
5. The method according to any one of claims 1-4, wherein the second request message is an attach request or a PDN connection setup request.
6. A session establishing method, the method comprising:

   The control plane function network element receives a first request message from the terminal for requesting establishment of a packet data unit PDU session; wherein the first request message includes a data network name DNN;

   Obtaining an access point name APN corresponding to the PDU session, where the APN is unique within the terminal range.
7. The method of claim 6 wherein the method further comprises:

   Sending a first response message to the terminal, where the first response message includes the APN.
8. The method of claim 7 wherein said APN is carried in a protocol configuration item PCO.
9. The method according to any one of claims 6-8, wherein the method further comprises:

   The control plane function network element sends information about the APN, the DNN, and the control plane function network element to the user data management network element.
10. A method according to any one of claims 6-9, wherein said APN is modified by said DNN modified by a value unique to said terminal range.
11. The method according to any one of claims 6-9, wherein the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, the obtaining The access point name APN corresponding to the PDU session includes:

    The APN is generated according to the PDU session identifier and/or the S-NSSAI, and the DNN.
12. The method according to any one of claims 6-9, wherein the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection assistance information S-NSSAI, the obtaining The access point name APN corresponding to the PDU session includes:

    The control plane function network element sends the PDU session identifier and/or the S-NSSAI, and the DNN to the user data management network element;

    The control plane function network element receives the APN from the user data management network element.
13. The method of any of claims 7-12, wherein the method further comprises receiving a session update request from a mobility management network element, the session update request including the APN.
14. The method of claim 6 wherein the method further comprises:

    Receiving a request sent by the mobility management network element to obtain the terminal session context;

    Transmitting a session context response to the mobility management network element, the session context response including the APN.
15. The method of any of claims 6-14, wherein the method further comprises:

    Obtaining contract data of the APN.
16. The method according to claim 15, wherein the acquiring the subscription data of the APN comprises:

    Generating subscription data of the APN according to the subscription data of the DNN; the method further includes:

    Sending the subscription data of the APN to the user data management network element.
17. A terminal, comprising: a sending module and a receiving module;

    The sending module is configured to send a first request message for establishing a packet data unit PDU session, where the first request message includes a data network name DNN;

    The receiving module is configured to receive a first response message, where the first response message includes an access point name APN corresponding to the PDU session, where the APN is unique within the terminal range;

    The sending module is further configured to send, to the mobility management network element, a second request message that establishes a PDN connection of the packet data network, where the second request message includes the APN.
18. The terminal according to claim 17, wherein the APN is carried in a protocol configuration item PCO.
19. The terminal according to claim 17 or 18, wherein the first request message further includes a PDU session identifier of the PDU session, and the first response message further includes the PDU session identifier; the terminal Also includes:

    And a saving module, configured to save the APN in a session context indicated by the PDU session identifier.
20. The terminal according to any one of claims 17 to 19, wherein the sending module is further configured to send indication information, where the indication information is used to indicate that all PDU sessions established by the terminal or a specific PDU session need to be subsequently switched to In the 4G network.
21. The terminal according to any one of claims 17 to 20, wherein the second request message is an attach request or a PDN connection establishment request.
22. A control plane function network element, comprising: a receiving module and an acquiring module;

    The receiving module is configured to receive a first request message from a terminal for requesting to establish a packet data unit PDU session, where the first request message includes a data network name DNN;

    The acquiring module is configured to acquire an access point name APN corresponding to the PDU session, where the APN is unique within the terminal range.
23. The control plane function network element according to claim 22, wherein the network element further comprises: a sending module;

    The sending module is configured to send a first response message to the terminal, where the first response message includes the APN.
24. The control plane function network element according to claim 23, wherein the APN is carried in a protocol configuration item PCO.
25. The control plane function network element according to any one of claims 23-24, wherein the sending module is further configured to send the APN, the DNN, and the control plane function network to a user data management network element. Meta information.
26. The control plane function network element according to any one of claims 22-25, wherein the APN is determined by modifying the DNN by a parameter having a unique value within the terminal range.
27. The control plane function network element according to any one of claims 22-25, wherein the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection auxiliary information S-NSSAI. The obtaining module is specifically configured to:

    The APN is generated according to the PDU session identifier and/or the S-NSSAI, and the DNN.
28. The control plane function network element according to any one of claims 22-25, wherein the first request message further includes a PDU session identifier of the PDU session and/or a single network slice selection auxiliary information S-NSSAI. The obtaining module is specifically configured to:

    Transmitting the PDU session identifier and/or the S-NSSAI, and the DNN to a user data management network element;

    Receiving the APN from the user data management network element.
29. The control plane function network element according to any one of claims 23-28, wherein the receiving module is further configured to receive a session update request from a mobility management network element, where the session update request includes the APN .
30. The control plane function network element according to claim 22, wherein the receiving module is further configured to receive a request for acquiring the terminal session context sent by the mobility management network element;

    The sending module is further configured to send a session context response to the mobility management network element, where the session context response includes information about the control plane function network element and the APN.
31. The control plane function network element according to any one of claims 22-30, wherein the acquiring unit is further configured to acquire subscription data of the APN.
32. The control plane function network element according to claim 31, wherein the obtaining module is configured to generate subscription data of the APN according to the subscription data of the DNN;

    The sending module is further configured to send the subscription data of the APN to the user data management network element.
33. An apparatus, comprising: a processor and a memory;

    The memory is operative to store computer-executed instructions that, when the device is in operation, execute the computer-executable instructions stored by the memory to cause the apparatus to perform any of claims 1-5 The session establishment method described.
34. The apparatus of claim 31 wherein said apparatus comprises a terminal or a chip within said terminal.
35. A control plane function network element, wherein the control plane function network element comprises a processor and a memory;

    The memory is configured to store a computer execution instruction, and when the control plane function network element is running, the processor executes the computer execution instruction stored in the memory, so that the control plane function network element executes as claimed The method of session establishment described in any one of 6-16.

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