Wireless communication method, wireless access device and core network device

Abstract

Provided are a wireless communication method, and a wireless access device or a core network device. The method comprises: a wireless access device sending an IP data packet to a core network element and / or receiving an IP data packet sent by the core network element, wherein the core network element is a session-related network element, and the IP data packet carries session-related information. Session-related information is exchanged between a wireless access device and a core network element on the basis of an IP data packet, such that signaling transmission in a session-related process does not require forwarding via access and an AMF, that is, the AMF can be decoupled from the session-related process, thereby reducing the signaling load of the AMF and reducing the costs of maintenance and upgrading of the AMF.

Description

Method, radio access device and core network device for wireless communication TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and more particularly, to a method, a radio access device and a core network device for wireless communication. BACKGROUND

[0002] The related procedures of a protocol data unit (PDU) session, such as establishment, modification, release and handover, are usually implemented based on complex signaling interaction between a terminal device and a core network. How to optimize the related procedures of the PDU session becomes a problem to be solved.

[0003] SUMMARY

[0004] The present application provides a method, a radio access device and a core network device for wireless communication. The aspects of the present application are described below.

[0005] In a first aspect, a method for wireless communication is provided, comprising: performing, by a radio access device, sending and / or receiving of an internet protocol (IP) packet with a core network element, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

[0006] In a second aspect, a method for wireless communication is provided, comprising: performing, by a core network element, receiving and / or sending of an IP packet with a radio access device, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

[0007] In a third aspect, a radio access device is provided, comprising: a transceiver configured to perform sending and / or receiving of an IP packet with a core network element, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

[0008] In a fourth aspect, a core network device is provided, comprising: a transceiver configured to perform receiving and / or sending of an IP packet with a radio access device, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

[0009] In a fifth aspect, a radio access device is provided, comprising a transceiver, a memory and a processor, the memory is configured to store a program, the processor is configured to invoke the program in the memory and control the transceiver to receive or send a signal, so that the radio access device performs the method of the first aspect.

[0010] In a sixth aspect, a core network device is provided, comprising a transceiver, a memory, and a processor, the memory is configured to store a program, the processor is configured to invoke the program in the memory and control the transceiver to receive or send a signal, so that the core network device performs the method in the second aspect.

[0011] In a seventh aspect, an apparatus is provided, comprising a processor configured to invoke a program from a memory, so that the apparatus performs the method in any one of the first aspect or the second aspect.

[0012] In an eighth aspect, a chip is provided, comprising a processor configured to invoke a program from a memory, so that a device installed with the chip performs the method in the first aspect or the second aspect.

[0013] In a ninth aspect, a computer readable storage medium is provided, having a program stored thereon, the program causing a computer to perform the method in the first aspect or the second aspect.

[0014] In a tenth aspect, a computer program product is provided, comprising a program, the program causing a computer to perform the method in the first aspect or the second aspect.

[0015] In an eleventh aspect, a computer program is provided, the computer program causing a computer to perform the method in the first aspect or the second aspect.

[0016] In the embodiments of the present application, the interaction between the wireless access device and the core network element based on the IP packet is used to exchange the session-related information, so that the signaling transmission in the session-related process does not need to be forwarded through the AMF, that is, the AMF can be decoupled from the session-related process, thereby reducing the signaling load of the AMF and reducing the cost of maintenance and upgrading of the AMF. BRIEF DESCRIPTION OF DRAWINGS

[0017] FIG. 1 is a schematic diagram of a network architecture to which the embodiments of the present application are applicable.

[0018] FIG. 2 is a schematic diagram of a PDU session establishment process.

[0019] FIG. 3 is a schematic diagram of a handover process based on an Xn interface.

[0020] FIG. 4 is a schematic diagram of a handover process based on an N2 interface.

[0021] FIG. 5 is a schematic diagram of a protocol stack for signaling interaction between a terminal device and a core network element.

[0022] FIG. 6 is a schematic diagram of a protocol stack for signaling interaction between an access network device and a core network element.

[0023] FIG. 7 is a schematic flow chart of a method of wireless communication, according to embodiments of the present disclosure.

[0024] FIG. 8 is a schematic flow chart of one implementation of the method of FIG. 7.

[0025] FIG. 9 is a schematic flow chart of another implementation of the method of FIG. 7.

[0026] FIG. 10 is a schematic flow chart of another implementation of the method of FIG. 7.

[0027] FIG. 11 is a schematic flow chart of another implementation of the method of FIG. 7.

[0028] FIG. 12 is a schematic flow chart of another implementation of the method of FIG. 7.

[0029] FIG. 13 is a schematic flow chart of another implementation of the method of FIG. 7.

[0030] FIG. 14 is a schematic diagram of a structure of a wireless access device, according to embodiments of the present disclosure.

[0031] FIG. 15 is a schematic diagram of a structure of a core network device, according to embodiments of the present disclosure.

[0032] FIG. 16 is a schematic diagram of an apparatus for communication, according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0033] The technical solutions in the present disclosure will be described below with reference to the accompanying drawings.

[0034] Wireless communication system

[0035] FIG. 1 is a schematic diagram of a network architecture, according to embodiments of the present disclosure. The network architecture can include a terminal device, an access network (AN) device, and a core network (CN) network element.

[0036] It should be understood that the technical solutions in the present disclosure can be applied to various communication systems, for example, a fifth generation (5G) system or new radio (NR), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, and the like. The technical solutions provided in the present disclosure can also be applied to future communication systems, for example, a sixth generation mobile communication system, a satellite communication system, and the like.

[0037] The terminal device in the embodiments of the present application can also be referred to as a user equipment (UE), an access terminal, a user unit, a user station, a mobile station, a mobile terminal (MT), a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless access device, a user agent or a user apparatus. The terminal device in the embodiments of the present application can refer to a device providing voice and / or data connectivity for a user, and can be used to connect people, things and machines, such as handheld devices with wireless connection function, vehicle-mounted devices, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer (Pad), a notebook computer, a palm computer, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. Optionally, the terminal device can be used to act as a base station. For example, the terminal device can act as a scheduling entity, which provides sidelink signals between terminal devices in vehicle to everything (V2X) or device to device (D2D), etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and the smart home device communicate with each other without relaying the communication signals through the base station.

[0038] An access network (AN) device can be an access device through which a terminal device accesses the network architecture by a wireless manner, and mainly responsible for radio resource management, quality of service (QoS) management, data compression and encryption, etc. on the air interface side. The access network device can also be referred to as a radio access network (RAN) device, for example, the access network device can be a base station. The base station can broadly cover various names in the following or replace the following names: Node B (NodeB), evolved Node B (eNB), next generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The base station can also refer to a communication module, modem or chip used in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device assuming the function of a base station in D2D, V2X, machine-to-machine (M2M) communication, a network side device in 6G network, a device assuming the function of a base station in future communication systems, etc. The base station can support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technology and specific device form adopted by the access network device.

[0039] The base station can be fixed or mobile. For example, a helicopter or a drone can be configured to act as a mobile base station, and one or more cells can move according to the location of the mobile base station. In other examples, the helicopter or the drone can be configured to serve as a device communicating with another base station.

[0040] In some deployments, the access network device in the embodiments of the present application can refer to a CU or a DU, or the access network device includes a CU and a DU. The gNB can also include an AAU.

[0041] The type of the core network element can include a UPF network element, an access and mobility management function (AMF) network element, a session management function (SMF) network element, a policy control function (PCF) network element, an application function (AF), a data network (DN), a network slice selection function (NSSF), an authentication server function (AUSF), a unified data management (UDM), a network exposure function (NEF), a network repository function (NRF), and a network slice-specific authentication and authorization function (NSSAAF). Among them, the UPF network element is mainly responsible for the transmission of user data and belongs to the user plane network element; the other network elements can be referred to as control plane function network elements, which are mainly responsible for authentication, authorization, registration management, session management, mobility management, and policy control, etc., to ensure reliable and stable transmission of user data.

[0042] The UPF can be used to forward and receive data of the terminal device. For example, the UPF can receive service data from a data network and transmit the data to the terminal device through the access network device; the UPF can also receive user data from the terminal device through the access network device and forward the data to the data network. Among them, the transmission resource allocated and scheduled by the UPF for the terminal device is managed and controlled by the SMF. The bearer between the terminal and the UPF can include a user plane connection between the UPF and the access network device, and a channel established between the access network device and the terminal. Among them, the user plane connection is a QoS flow that can be established between the UPF and the access network device to transmit data.

[0043] The AMF can be used to manage terminal access to a core network, for example: location update of terminal equipment, registration network, access control, mobility management of terminal equipment, attachment and detachment of terminal equipment, etc. The AMF can also provide storage resources for the control plane of a session for the terminal equipment to provide services for the session, to store session identifiers, identifiers of SMFs associated with the session identifiers, etc.

[0044] The SMF can be used to select a user plane network element for a terminal device, redirect a user plane network element for a terminal device, allocate an internet protocol (IP) address for a terminal device, establish a bearer (also referred to as a session) between the terminal device and the UPF, modify, release and QoS control of the session.

[0045] The PCF is used to provide policies to the AMF and the SMF, such as QoS policies, slice selection policies, etc.

[0046] The AF is used to interact with 3GPP core network elements to support application influence data routing, access network exposure functions, and interact with PCF for policy control, etc.

[0047] The DN can provide data services for users, such as IP multi-media service (IMS) networks, the Internet, etc. There can be various application servers (ASs) in the DN to provide different application services, such as operator services, Internet access, or third-party services, etc. The AS can implement the functions of the AF.

[0048] The NSSF is used for network slice selection, and the supported functions include, for example: selecting a set of network slice implementations to serve a terminal device; determining allowed network slice selection assistance information (NSSAI), and determining the mapping to single-network slice selection assistance information (S-NSSAI) of a subscription when needed; determining configured NSSAI, and determining the mapping to S-NSSAI of a subscription when needed; determining a set of AMFs that can be used to query a terminal device, or determining a list of candidate AMFs based on configuration.

[0049] The AUSF is used to receive a request for terminal equipment authentication from the AMF, request a key from the UDM, and then forward the issued key to the AMF for authentication processing.

[0050] The UDM includes generation and storage of user subscription data, management of authentication data, and the like, and supports interaction with external third-party servers.

[0051] The NEF is used for capability exposure, that is, based on the NEF, the capability of the network can be output to an external network. An external untrusted application can access internal data of the core network through the NEF to ensure the security of the network. The NEF can provide external application QoS capability exposure, event subscription, AF request distribution, and the like.

[0052] The NRF is used for registration, management, and state detection of core network elements, thereby realizing automatic management of the core network elements. When a core network element is started, it must be registered with the NRF to provide services. The registration information can include, for example, the type, address, and service list of the core network element.

[0053] In addition, in a 5G network for example, a network data analysis function (NWDAF) is also added in the core network. Based on the NWDAF, data can be collected from various network elements, network management systems, and the like of the core network, and big data statistics, analysis, or intelligent data analysis can be performed, thereby obtaining analysis or prediction data on the network side, and further assisting various network elements in more effective control of terminal device access according to the data analysis results.

[0054] In a 5G system for example, the core network element can also be referred to as a network function (NF).

[0055] The various network elements in FIG. 1 can be network elements in a hardware device, software functions running on a dedicated hardware, or virtualized functions instantiated on a platform such as a cloud platform. It should be noted that in the network architecture shown in FIG. 1, only the network elements included in the entire network architecture are exemplarily illustrated. The embodiments of the present application do not limit the network elements included in the entire network architecture.

[0056] Those skilled in the art can understand that the network architecture shown in FIG. 1 does not constitute a limitation on the network architecture, and in actual implementation, the network architecture can include more or fewer network elements than shown, or some network elements can be combined, and the like.

[0057] It should be understood that the AN or RAN is represented in the form of (R)AN in FIG. 1. In the embodiments of the present application, the terminal device and the access network device can be collectively referred to as a wireless access device. The wireless access device and the core network element can also be referred to as a network device.

[0058] In some scenarios, the network device and the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on water; and can also be deployed on airplanes, balloons and satellites in the air. The scenario in which the network device and the terminal device are located is not limited in the embodiments of the present application.

[0059] By way of example and not limitation, in the embodiments of the present application, the network device can have a mobile characteristic, for example, the network device can be a mobile device. In some embodiments of the present application, the network device can be a satellite, a balloon station. For example, the satellite can be a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, etc. In some embodiments, the network device can also be a base station arranged at a position on land, water, etc.

[0060] In the embodiments of the present application, the network device can serve a cell, and the terminal device communicates with the network device through transmission resources (for example, including frequency domain resources, or frequency spectrum resources) used by the cell. The cell can be a cell corresponding to the network device (for example, a base station), and the cell can belong to a macro base station or a base station corresponding to a small cell. The small cell can include a metro cell, a micro cell, a pico cell, a femto cell, etc., and these small cells have the characteristics of small coverage and low transmit power, and are suitable for providing high-speed data transmission services.

[0061] PDU session establishment

[0062] The PDU session establishment procedure is used to create a new PDU session for the terminal device and allocate end-to-end user plane connection resources between the terminal device and a UPF, for example, a PDU session anchor (PSA). As shown in the PDU session establishment procedure of FIG. 2, due to the separation design of mobility management and session management, in some networks, for example, an NR network, the terminal device does not directly complete the establishment of the session when initially registering to the network, but triggers the establishment of the session as needed after the registration is completed. When a network communication is initiated by an application, the terminal device determines whether to trigger the session establishment procedure shown in FIG. 2 to establish end-to-end user plane transmission resources for the application according to a user route selection policy (URSP) rule corresponding to the application or local configuration.

[0063] As an example, as shown in FIG. 2, in step 201, the terminal device sends a session establishment request message to the AMF.

[0064] The session establishment request message includes parameters required for session establishment, such as session identity, session type, session and service continuity mode (SSC mode), data network name (DNN) of PDU session connection, S-NSSAI. The terminal device may, for example, determine part of the request parameters in the session establishment request message according to the corresponding URSP rule of the application.

[0065] In step 202, the SMF is selected.

[0066] The AMF selects a suitable SMF for the session established by the terminal device according to information such as DNN, S-NSSAI, and subscription data. For multiple session requests established by the terminal device in the same data network and slice, the AMF tries to select the same SMF to reduce the number of SMFs serving the same terminal device.

[0067] In step 203, the AMF invokes the session service of the SMF selected by the AMF to trigger the establishment of the PDU session.

[0068] In step 204, the SMF obtains subscription data.

[0069] The SMF obtains session management subscription data from the UDM, for example, including information such as user-allowed SSC mode, session type, default session parameter value, and subscribed session aggregate maximum bit rate (session-AMBR).

[0070] In step 205, the SMF performs secondary authentication and authorization of the PDU session with a third-party authentication, authorization, and accounting (AAA) server in the DN.

[0071] Step 205 is optional.

[0072] In step 206, the SMF selects a PCF and a UPF for the PDU session.

[0073] In step 207, the SMF establishes a session management policy connection with the PCF and obtains session policy rules.

[0074] In step 208, the SMF establishes an end-to-end user plane connection between the terminal device, the access network device and the UPF.

[0075] In this process, the SMF sends a session establishment acceptance message to the terminal device through the AMF and the AN, which includes, for example, the selected SSC mode, the selected session type, the S-NSSAI, the DNN and the like.

[0076] In step 209, the SMF registers with the UDM, and the UDM records the identity of the SMF corresponding to the session.

[0077] In step 210, the SMF allocates an IP address for the terminal device.

[0078] In the case of IPv6 or IPv4 session type, the SMF generates a router advertisement (RA) message carrying the IPv6 prefix allocated for the session.

[0079] PDU session handover: Xn interface-based handover procedure

[0080] The process of switching a terminal device from a source base station (S-RAN) to a target base station (T-RAN) can be referred to as an Xn interface-based handover procedure. In the preparation phase of PDU session handover, the source base station needs to send the cell identity, access layer configuration, mapping relationship between current QoS flow and DRB, PDU session related information of the target cell to the target base station. The target base station performs admission control on the terminal device, determines to accept or reject some PDU sessions according to the supported slices, and sends a handover request confirmation message to the source base station. The source base station can send an RRC reconfiguration message to the terminal device to instruct the terminal device to perform handover. The terminal device performs handover based on the RRC reconfiguration message and sends an RRC reconfiguration complete. Thereafter, the handover execution phase is entered.

[0081] As an example, as shown in FIG. 3, the Xn interface-based handover procedure, in step 301, after the air interface handover is completed, the target base station sends a path switching request message to the AMF.

[0082] The path switching request message includes, for example, PDU sessions and N2 messages that need to be switched, PDU sessions and N2 messages that fail to switch, location information of the terminal device, and the like. If all QoS flows of a PDU session are not accepted by the target base station, or the target base station does not support the session-related slice, the session handover fails.

[0083] In step 302, the AMF finds the corresponding SMF through the locally stored session context of the terminal device according to the session identifier of the PDU session that is successfully or unsuccessfully switched, and notifies the SMF to update the session information, for example, including the SMF reestablishing the N3 connection between the RAN and the UPF.

[0084] In step 303, the AMF sends a path switching confirmation message in response to the path switching request message.

[0085] In step 304, the AMF instructs the source base station to release resources.

[0086] In step 305, if the terminal device moves out of the RA, a subsequent mobility registration update procedure needs to be initiated.

[0087] For the PDU session that is successfully switched, if there is a failed QoS flow, the SMF will initiate a PDU session modification procedure after the switching is completed. For the PDU session that is unsuccessfully switched, the SMF performs a PDU session release or deactivation procedure according to different reasons.

[0088] PDU session switching: N2 interface-based switching procedure

[0089] Figure 4 shows an N2 interface-based switching procedure. The N2 interface is an interface connecting the access network device and the AMF, and is mainly used for terminal device mobility management, session management, and related control signaling transmission. In Figure 4, the PSA is an anchor UPF, i.e., an anchor UPF in a DNN, or understood as a UPF with a data network exit. Each PDU session has at least one PSA. The source UPF and the target UPF belong to intermediate UPFs (I-UPFs), which are used to classify, route, and forward user data from different PSAs, and ensure that data can accurately reach the target data network.

[0090] As shown in Figure 4, in step 401, the source base station sends a handover required message to the AMF.

[0091] The handover required message includes, for example, the identification information of the target base station, the related information of the PDU session that needs to be switched, and the like.

[0092] In step 402, the AMF sends a PDU session message update request message to the corresponding SMF to update the corresponding PDU session information according to the PDU session message that needs to be switched, in combination with the slices that the AMF can serve.

[0093] In step 403, the SMF confirms whether the corresponding PDU session can be switched, and the SMF determines whether an I-UPF needs to be inserted according to the location of the terminal device, and establishes an uplink between UPFs for transmission of uplink data.

[0094] In step 404, the SMF sends a PDU session update response message to the AMF according to whether the PDU session is successfully established.

[0095] The session update response message includes, for example, session management (SM) information of the relevant N2 interface or a failure cause value.

[0096] In step 405, the AMF sends a handover request message to the target base station.

[0097] The handover request message includes, for example, the message sent by the source base station, and SM information and MM information of the N2 interface.

[0098] The SM information is, for example, information related to session management of the terminal device; and the mobility management (MM) information is, for example, information related to mobility management of the terminal device. The SM information and the MM information can be usually transparently transmitted by the AMF based on the N2 interface, that is, the AMF acts as a transparent point to transparently transmit the SM information and the MM information between the access network device and the SMF.

[0099] In step 406, the target base station can determine the PDU sessions that can be switched and the PDU sessions that are rejected for switching according to the slices and QoS flows that the target base station can support, and sends a handover request acknowledgement message to the AMF.

[0100] The handover request acknowledgement message includes, for example, the result of the determination and an N2 message.

[0101] In step 407, the AMF sends a PDU session update request message to the SM to forward the information received from the target base station to the SMF.

[0102] For the QoS flows for which the session establishment fails in the target base station, the SMF initiates a PDU session modification procedure after the handover is completed. For the PDU sessions that are rejected for switching, the SMF selects to release the session or deactivate the session.

[0103] In step 408, the SMF establishes an uplink forwarding path from the RAN to the UPF for the PDU sessions that can be switched.

[0104] If an indirect forwarding path needs to be established, an indirect forwarding path between the source UPF and the target base station also needs to be established in step 408.

[0105] In step 409, the AMF acquires information that needs to be sent to the source base station.

[0106] The information includes, for example, a PDU session establishment message and information of an S-UPF for forwarding when an indirect forwarding path exists.

[0107] In step 410, after receiving the information about the handover sent by the AMF, the source base station sends a handover command to the terminal device to instruct the terminal device to perform handover. Correspondingly, the terminal device sends a handover confirmation message to the target base station. And the target base station informs the AMF of the success of the handover.

[0108] In step 411, if the AMF cannot support some PDU sessions due to some slice reasons, the AMF can trigger a PDU session release procedure. For other sessions, the AMF can trigger a session update procedure to update the information of the PDU session at the SMF.

[0109] In step 412, the SMF interacts with the UPF to establish a downlink between the UPFs for transmission of downlink data.

[0110] In step 413, the SMF deletes the indirect forwarding tunnel established in step 408.

[0111] It can be understood that once the handover procedure is completed and the user plane data has been successfully transmitted from the source base station to the target base station, and the target base station has taken over the transmission of the user's data, the indirect forwarding path can be considered for deletion at this time. This is because the indirect forwarding path is mainly used to support data transmission during the handover procedure.

[0112] In the existing PDU session related procedures, for example, in the above-mentioned PDU session handover procedure, the AMF needs to perform mobility restriction related checks on the services being handed over, and serve as an anchor point for signaling transmission, aggregating the signaling interaction between the terminal device and other core network elements. For example, the AMF needs to find the SMF corresponding to the PDU session, respectively trigger each SMF to initiate PDU session modification, release the rejected QoS flow, and establish a new general packet radio service (GPRS) tunneling protocol (GTP-U) tunnel between the anchor UPF and the target base station. In the process of establishing the new GTP-U tunnel, each UPF needs to provide the core network tunnel information to the target base station through the AMF, and the AMF also needs to help the target base station provide the tunnel information to each UPF, thereby causing the AMF to need to aggregate and forward a large amount of signaling information, bringing a huge signaling load to the AMF.

[0113] In the embodiments of the present application, it is considered not to select the AMF as the anchor point in the PDU establishment switching process and the like, however, since there is no information related to the mobility restriction in the SMF, it is unable to verify whether the service is allowed to be switched to a new area. In addition, since the UPF and the access network device are unable to directly communicate with each other, a new mechanism needs to be provided to realize the interaction of the tunnel information between the access network device and the UPF without the AMF.

[0114] Therefore, in the method for wireless communication provided in the embodiments of the present application, the interaction of the session related information between the wireless access device and the core network element is based on the IP packet, so that the signaling transmission in the session related process does not need to be forwarded through the AMF, that is, the AMF can be decoupled from the related process of the PDU session and exist as an access and mobility management network element independently, thereby reducing the signaling load of the AMF and the cost of maintenance and upgrading of the AMF.

[0115] FIGS. 5 and 6 show the protocol stack applicable to the communication method of the embodiments of the present application, taking the 5G system as an example, FIG. 5 shows the end-to-end protocol stack of the signaling interaction between the terminal device and the core network element based on the IP packet, and FIG. 6 shows the end-to-end protocol stack of the signaling interaction between the access network device and the NF based on the IP packet. Hereinafter, the core network element is also referred to as a network function (NF).

[0116] As shown in FIG. 5, the signaling transmission between the terminal device and the NF can be based on the IP protocol, and the information exchanged is carried in the IP packet. As an example, the terminal device can include an access network protocol layer (AN Protocol Layer), an IP layer, a transport layer (transport layer) and a non-access layer (non-access stratum, NAS); the NF can include a lower layer, an IP layer, an inner IP layer, a transport layer and a NAS layer; the access network device can include an access network protocol layer for communication with the terminal device, an IP layer, and a lower layer, an IP layer and an inner IP layer for communication with the NF, and further includes a relay layer. Among them, the lower layer includes, for example, a physical layer (i.e., layer 1) and a data link layer (i.e., layer 2). Optionally, the formation of the IP packet can be based on the inner IP layer protocol and the IP layer protocol, that is, a two-layer protocol stack such as IP in IP protocol is adopted. As an example, the inner packet header of the IP packet can include the address of the terminal device as the destination address, and the outer packet header can include the address of the access network device serving the terminal device as the destination address. The interface between the NF and its external system can be, for example, a service-based interface (Service Based Interface, SIB).

[0117] As shown in FIG. 6, the signaling interaction between the access network device and the NF can also be based on the IP protocol, and the information exchanged is carried in the IP packet. As an example, the access network device can include a bottom layer, an IP layer, a transport layer, and an application layer; and correspondingly, the NF includes a bottom layer, an IP layer, a transport layer, and an application layer.

[0118] In this way, the AMF, which only performs mobile management related processing, does not need to be used as an anchor point for aggregating and forwarding signaling. In this way, on the one hand, when the terminal device requests to perform a session establishment, modification, or release process, the terminal device can directly negotiate with the SMF to perform session establishment, modification, or release. On the other hand, when the terminal device requests to perform session switching, the target access network device can interact with all core network network elements individually, thereby reducing the workload of the AMF.

[0119] The embodiments of the present application will be described in detail below with reference to FIG. 7.

[0120] FIG. 7 is a flow diagram of a wireless communication method provided by an embodiment of the present application. The method 700 shown in FIG. 7 can be performed by a wireless access device and a core network device. Hereinafter, the core network device is also referred to as a core network network element. The wireless access device may, for example, include a terminal device and / or an access network device. If the wireless access device is a terminal device, the transmission of the IP packet between the terminal device and the core network network element needs to pass through the access network device. The core network network element may, for example, include other network elements other than the AMF. If network element reselection occurs, the core network network element may, for example, be a source core network network element and / or a target access network network element.

[0121] Referring to FIG. 7, the method 700 described in FIG. 7 includes step 710 and / or step 720.

[0122] In step 710, the wireless access device sends an IP packet to the core network network element.

[0123] In step 720, the core network network element sends an IP packet to the wireless access device.

[0124] Optionally, the core network network element is a session related network element, for example, including an SMF, a UPF, an NRF, a UDM, and the like. The IP packet carries session related information, for example, related information involved in the session establishment, release, modification, switching, and the like.

[0125] It should be noted that, in the embodiments of the present application, the session may refer to, for example, a PDU session in the NR system, a packet data network (PDN) connection in the 4G system, a data channel or a data connection established in a future communication system for transmitting user data, and the like.

[0126] In the following, the technical solutions of the embodiments of the present application will be described in combination with Embodiments 1 to 5.

[0127] Embodiment 1

[0128] In some implementations, the wireless access device in the embodiments of the present application includes a terminal device, and the core network network element in the embodiments of the present application includes a session management network element, such as an SMF, and the like. The session-related information carried in the IP packet includes: a session request message sent by the terminal device to the session management network element; and / or a session response message sent by the session management network element to the terminal device in response to the session request message, which may include, for example, a session acceptance message or a session rejection message.

[0129] For example, the session request message is a session establishment request message, and correspondingly, the session response message is a session establishment response message in response to the session establishment request message; for another example, the session request message is a session modification request message, and correspondingly, the session response message is a session modification response message in response to the session modification request message; for yet another example, the session request message is a session release request message, and correspondingly, the session response message is a session release response message in response to the session release request message.

[0130] In some implementations, the session request message further includes one or more of the following: an identifier of a session to be established; an identifier of a session to be released; an S-NSSAI; a DNN; a type of the session request message; an SSC mode; address information of the terminal device; and identification information of the terminal device. The type of the session request message may include, for example, an initial request, an emergency session establishment request, a handover, and the like.

[0131] For example, the address information of the terminal device may include an IP address, such as an IPv6 address or an IPv4 address, and the like; the address information of the terminal device may also include a MAC layer address or other hardware address, a physical address, an Ethernet address, and other addresses that can find the terminal device. The session management network element may send the session response message to the terminal device based on the address information of the terminal device.

[0132] It should be noted that the IP address of the terminal device can be an IP address allocated by the system to the terminal device after registration, which is a static address and is used for signaling interaction with the core network element. As an example, the address information of the terminal device can be carried in the header of the IP data packet as the source address of the IP data packet.

[0133] In addition, in the embodiments of the present application, the identification information of the terminal device can include, for example, the access stratum (AS) identification of the terminal device, such as the radio network temporary identifier (RNTI), the international mobile subscriber identification number (TMSI), etc.; the identification information of the terminal device can also include the NAS layer identification of the terminal device, such as the globally unique temporary UE identity (GUTI), the subscription concealed identifier (GUTI), etc.

[0134] In some implementations, the session acceptance message described above includes one or more of the following: a session identifier; information indicating acceptance of the session request (i.e., session acceptance information); a selected session type; a selected SSC mode; a selected S-NSSAI; authorized QoS rules; a session address allocated to the terminal device for the session.

[0135] Among them, the session type described above defines, for example, the protocol of the terminal device carried by the session, such as IPv4, IPv6, IPv4 / IPv6 dual stack, Ethernet, unstructured, etc.

[0136] As an example, the SSC modes can include SSC mode 1, SSC mode 2 and SSC mode 3, where the SSC mode 1 is mainly applicable to services with relatively high continuity requirements, such as automatic driving services, which always support the continuity of services, and the IP address of the terminal device does not change; the SSC mode 2 is mainly applied to video services with certain buffering, and needs to release the old session and IP address and re-establish a new session, and there may be interruption of services in between; and the SSC mode 3 is mainly applied to web browsing services and the like, and needs to establish a new session before the old session is released, so as to ensure the continuity of services, and the IP address will change, but the service will not be interrupted. Among them, in the case of triggering the SSC mode 3, the session identifier of the old session needs to be included in the session request message, i.e., the session identifier of the session to be released.

[0137] The session address is an address used for interaction with the server, and the session address is a dynamic address which is bound with the session. The purpose of configuring the session address is to allocate the IP address to the terminal device.

[0138] In some implementations, the session rejection message includes one or more of the following: a session identifier; information indicating rejection of the session request (i.e., session rejection information); and a reason for rejecting the session request. The reason for rejecting the session request may include, for example, an uncertain DNN, rejected QoS parameters, and secondary authentication failure.

[0139] In some implementations, in the case where the session request is accepted, the method 700 can further include, in the case where the session request is accepted, the session management network element registering with the UDM, where the information recorded by the UDM after registration includes: address information of the terminal device, such as address information used for signaling transmission; and / or the session address corresponding to the session.

[0140] When the terminal device sends the session request message to the session management network element, it needs to know the address of the session management network element. Therefore, in some implementations, the method 700 can further include that the terminal device obtains session management network element related information from the NRF. The session management network element related information is used by the terminal device to send the session request message to the session management network element. That is, the terminal device needs to send the session request message to the session management network element based on the session management network element related information, such as address information of the session management network element.

[0141] The data transmission between the NRF and the terminal device can be based on an IP packet or not. As an example, the core network element in the embodiments of the present application can also include the NRF, that is, the NRF interacts with the terminal device based on an IP packet. At this time, the session-related information carried in the IP packet can include: a network element information request message sent by the terminal device to the NRF; and / or a network element information response message sent by the NRF to the terminal device in response to the network element information request message. The network element information response message carries the session management network element-related information.

[0142] In some implementations, the network element information request message includes one or more of the following: identification information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; S-NSSAI; DNN; and access type of the session.

[0143] In some implementations, the session management network element-related information carried in the network element information response message can include one or more of the following: identification information of the terminal device; type information of the session management network element; address information of the session management network element; and identification information of the session management network element.

[0144] The location information of the terminal device is, for example, a tracing area identification (TAI) of the terminal device, a cell ID, or can also be coordinate information of the latitude and longitude of the terminal device.

[0145] The type information of the session management network element is, for example, the type of the session management network element, which is used to indicate which network element (for example, the session management network element) the network element information request message requests to obtain information. The DNN is used to identify the accessed data network. The access type includes, for example, 3GPP access or non-3GPP access (such as Wi-Fi) access.

[0146] After receiving the session request message sent by the terminal device, the session management network element needs to determine whether to receive or reject the session request message. For example, in some implementations, the method 700 can also include that the session management network element obtains the subscription data of the terminal device from the UDM, and determines to receive or reject the session request message based on the subscription data. The subscription data includes, for example, the SSC mode allowed by the terminal device, the session type, the default session parameter value, the subscribed session aggregation maximum bit rate, the IP address, and the like.

[0147] If the session request message is for a local area data network (LADN), the session management unit also needs to verify whether the terminal device is in the service area of the LADN. For example, in some implementations, if the DNN carried in the session request message sent by the terminal device to the session management network element is a LADN, the method 700 can further include: the session management network element obtains the service area of the LADN, and determines whether the terminal device is located in the service area of the LADN. The service area of the LADN can be obtained in one or more of the following ways: from the AMF; from the UDM; from the local configuration.

[0148] Embodiment 1 will be described in more detail below in conjunction with FIG. 8. FIG. 8 is an example of a PDU session establishment process. It is assumed that both the terminal device and the access network device can communicate with the core network element based on IP packets in a point-to-point manner, and the signaling interaction in the PDU session establishment process is shown in FIG. 8.

[0149] In step 801, the terminal device sends a network element information request message to the NRF, and the NRF selects a suitable SMF for the terminal device based on the network element request message, and sends a network element information response message to the terminal device to return the information of the selected SMF to the terminal device.

[0150] The network element information request message, for example, includes one or more of the following: identification information of the terminal device; address information of the terminal device; type of the SMF; address of the SMF; location information of the terminal device; S-NSSAI; DNN; access type of the PDU session.

[0151] The network element response message, for example, includes one or more of the following: identification information of the terminal device; type of the SMF; address information of the SMF; identification information of the SMF.

[0152] In step 802, the terminal device sends a PDU session establishment request message to the SMF.

[0153] The PDU session request message includes one or more of the following: session identifier of the PDU session; old PDU session identifier; S-NSSAI(s); DNN requested by the terminal device; type of the session establishment request message; requested SSC mode; address of the terminal device (e.g., carried as a source address in the packet header of an IP packet); identification information of the terminal device.

[0154] In step 803, the SMF obtains the subscription data of session management from the UDM, i.e. subscription retrieval.

[0155] The subscription data includes, for example, SSC mode allowed by the terminal device, session type, default session parameter value, subscribed session aggregation maximum bit rate, IP address information, and the like.

[0156] The SMF verifies whether to receive the PDU session establishment request of the terminal device based on the subscription data. If the DNN requested by the terminal device is an LADN, the SMF also needs to verify whether the terminal device is in the service area of the LADN. For example, the SMF can obtain the service area of the LADN from the AMF or the UDM, or obtain the service area of the LADN based on local configuration. If the verification is successful, the SMF will send a PDU session establishment accept message to the terminal device in the following steps, otherwise a PDU session establishment reject message will be sent to the terminal device, see step 809.

[0157] In step 804, during the establishment of the PDU session, the SMF can perform secondary authentication through a DN-AAA server (also referred to as DN-AAA), also known as secondary authentication / authorization (PDU Session authentication and authorization) or secondary authentication.

[0158] The detailed content of step 804, i.e. the secondary authentication process, will be described in embodiment 2.

[0159] In step 805, the SMF selects a suitable PCF and UPF.

[0160] In step 806, the establishment or modification of the session management policy association (SM policy association establishment / modification) is performed, so as to establish the session management policy association between the SMF and the PCF, and obtain the session policy rule.

[0161] In step 807, the SMF establishes the user plane connection, i.e. the end-to-end user plane connection between the terminal device, the access network device and the UPF, also known as the user plane path (UP path).

[0162] The detailed content of step 807, i.e. the user plane path establishment, will be described in embodiment 3.

[0163] In step 808, if the PDU session establishment is successful, the SMF registers with the UDM.

[0164] The UDM records the identifier of the SMF corresponding to the PDU session, the identifier of the terminal device, the DNN, the S-NSSAI, and the address information of the terminal device, such as the IP address information and / or the PDU session address.

[0165] In step 809, the SMF sends an IP data packet to the terminal device based on the address information of the terminal device.

[0166] The IP data packet carries the PDU session acceptance information or the PDU session rejection information.

[0167] The PDU session acceptance information includes one or more of the following: the PDU session identifier; the PDU session establishment accept; the selected PDU session type; the selected SSC mode; the selected S-NSSAI; the authorized QoS rule; and the address information of the PDU session allocated to the terminal device.

[0168] The PDU session rejection information includes one or more of the following: the PDU session identifier; the PDU session establishment reject; and the reason for rejecting the PDU session.

[0169] In the conventional interaction process, for example, the PDU session establishment process shown in FIG. 2, since the session request message and the session response message need to be forwarded through the AMF, the signaling load of the AMF is greatly increased. In the scheme of embodiment 1, for example, the PDU session establishment process shown in FIG. 8, since the session request message and the session response message are carried in the IP data packet, the transmission between the terminal device and the session management network element can be realized without the forwarding of the AMF, and the direct interaction between the terminal device and the SMF is realized to complete the establishment of the PDU session, which can decouple the AMF from the related process of the PDU session, reduce the deployment cost of the AMF, and reduce the signaling load of the AMF.

[0170] In addition, in a conventional interaction process, such as the PDU session establishment process shown in FIG. 2, the terminal device sends a session request message to the AMF and forwards it to the SMF through the AMF, and the AMF also needs to perform session management related operations, such as selecting a suitable SMF for the terminal device based on the information sent by the terminal device. Among them, the PDU session request message is carried in the SM container of the N1 interface and sent to the AMF, the SM container is invisible to the AMF, and the AMF only transmits the SM container. Therefore, when the terminal device sends the PDU session establishment request message to the AMF, the outside of the SM container also needs to include some information that is the same as the internal information of the SM container, such as the identification information of the PDU session, the type information of the PDU session, and the like (the present embodiment does not list all the parameters that the PDU session request may carry), so as to facilitate the AMF to perform session management related operations. In this way, there is a lot of repeated information inside and outside the SM container. By using the solution of embodiment 1, such as the PDU session establishment process shown in FIG. 8, the transmission of this part of repeated information can be directly reduced, the data redundancy is greatly reduced, the message length is shortened, and the air interface and network side resources are saved.

[0171] Embodiment 2

[0172] The secondary authentication process of the PDU session, that is, the authentication / authorization process, can be triggered by a session management network element, such as an SMF, during PDU session establishment. If the DN-AAA server is located in the core network, such as a 5G core (5GC), and can be directly accessed, the session management network element can directly interact with the DN-AAA server, otherwise the signaling between the two needs to be transparently forwarded through a user plane network element, such as a UPF, to realize the interaction. The authentication between the terminal device and the DN-AAA server in the external data network can apply the extensible authentication protocol (EAP) framework. Among them, the session management network element should play the role of EAP verifier, and rely on the external DN-AAA server to verify and authorize the session establishment request initiated by the terminal device.

[0173] In some implementations, the session related information carried in the IP packet can also include: a session authentication command message sent by the session management network element to the terminal device; and / or a session authentication completion message sent by the terminal device to the session management network element.

[0174] The session authentication command message carries, for example, an authentication / authorization request sent by the DN-AAA server, such as an EAP-request message, etc. The session authentication complete message carries an authentication / authorization response, such as an EAP-response message. The EAP-request message and the EAP-response message are used for secondary authentication of the terminal device.

[0175] Specifically, the session management network element receives the EAP request from the DN-AAA server and sends the EAP request sent by the DN-AAA server to the terminal device. The session management network element receives the EAP response from the terminal device and sends the EAP response sent by the terminal device to the DN-AAA server.

[0176] In some implementations, the session authentication command and / or the session authentication complete message further carries information of a data network specific identity (DN-specific identity). The data network specific identity is used to verify the identity and authority of the user to access a specific data network in the secondary authentication process.

[0177] The above-mentioned interaction process can be repeatedly performed between the terminal device and the session management network element. The DN-AAA server can confirm the successful authentication of the PDU session after multiple rounds of interaction. Optionally, the DN-AAA server can send an authentication success message or an authentication failure message to the session management network element. The session management network element receives the authentication success message or the authentication failure message sent by the DN-AAA server. Optionally, the DN-AAA server can send one or more of the following to the session management network element: information indicating the success of the session authentication; data network authorization data (DN Authorization Data); a notification request message; and a session address of the PDU session.

[0178] The information indicating the success of the session authentication is, for example, an SM PDU DN response container. The data network authorization data includes, for example, a series of policies, QoS, address information, etc. provided by the data network. The notification request message includes, for example, a request to learn the IP address and / or N6 traffic routing information allocated to the session, or the MAC address used by the terminal device in the session. The session address of the PDU session includes, for example, an IP address or an IPv6 prefix.

[0179] Embodiment 2 is described in more detail below in connection with FIG. 9. FIG. 9 is an example of the secondary authentication procedure in step 804 of the PDU session establishment procedure shown in FIG. 8. It is assumed that both the terminal device and the access network device can communicate with the core network element based on IP packets in a point-to-point manner, and the signaling interaction in the secondary authentication procedure is shown in FIG. 9.

[0180] In step 901, if there is no N4 session, i.e., an N4 session, the SMF selects a UPF and triggers the establishment of the N4 session.

[0181] The N4 session can be used to transmit messages related to the data network between the SMF and the data network,

[0182] In step 902, the SMF initiates an authentication procedure between the UPF and the DN-AAA server, and sends an authentication / authorization request message to the DN-AAA server to request verification of the data network specific identity provided by the terminal device.

[0183] The data network specific identity should comply with the network access identifier (NAI) format. In the available case, the SMF provides a generic public subscription identifier (GPSI) in the signaling exchanged with the DN-AAA server, where the GPSI is an external identifier of the terminal device, i.e., a public user identifier used by the terminal device in a network outside the 3GPP system, for cross-network identity recognition and authentication.

[0184] The UPF can transparently forward the message received from the SMF to the DN-AAA server; and / or transparently forward the message received from the DN-AAA server to the SMF.

[0185] In step 903, the DN-AAA server sends an authentication / authorization response message to the SMF.

[0186] The authentication / authorization response message can carry, for example, EAP request information.

[0187] In step 904, the SMF sends a PDU session authentication command message to the terminal device.

[0188] The PDU session authentication command message carries EAP request information. The EAP request information can be encapsulated based on the EAP protocol, and the encapsulated EAP request information is encapsulated again based on the 3GPP protocol to form the PDU session authentication command message. The PDU session authentication command message can be carried in an IP data packet and directly sent to the terminal device without forwarding through the AMF, and the data network specific identity can also be carried in the IP data packet and sent to the terminal device.

[0189] In step 905, the terminal device sends a PDU session authentication complete message to the SMF.

[0190] The PDU session authentication complete message carries EAP response information. The EAP response information can be encapsulated based on the EAP protocol, and the encapsulated EAP response information is encapsulated again based on the 3GPP protocol to form the PDU session authentication complete message. The PDU session authentication complete message can be carried in an IP data packet and directly sent to the SMF without forwarding through the AMF, and the data network specific identity can also be carried in the IP data packet and sent to the SMF.

[0191] In step 906, the DN-AAA server sends an authentication success message, i.e., an EAP-success message, to the SMF through the UPF, or sends an authentication failure message, i.e., an EAP-failure message, to the SMF.

[0192] In addition, the DN-AAA server can provide one or more of the following information to the session management network element: information indicating that the session authentication is successful; data network authentication data; a notification request message; a session address of the PDU session, and the like.

[0193] In embodiment 2, the terminal device and the SMF directly carry NAS signaling through an IP data packet to realize signaling interaction in the secondary authentication process, thereby decoupling the AMF from the secondary authentication process, reducing the design cost and signaling load of the AMF, and reducing the interaction delay between the terminal device and the DN-AAA server.

[0194] Embodiment 3

[0195] As an example, the user plane path in the session of Embodiment 3 includes an N3 connection between the terminal device and the access network device, and a GTP-U tunnel between the access network device and the UPF. The establishment of the GTP-U tunnel requires the anchor UPF to obtain the access network tunnel information (AN tunnel info) of the access network device for the transmission of downlink data, and the access network device to obtain the core network tunnel information (CN tunnel info) of the UPF for the transmission of uplink data. The transmission of the core network tunnel information and the access network tunnel information can also be based on IP packets.

[0196] In some implementations, the wireless access device further includes an access network device, and the session-related information carried in the IP packet further includes: core network tunnel information sent by the core network network element to the access network device; and / or, access network tunnel information sent by the access network device to the core network network element. The core network tunnel information and the access network tunnel information are used to establish a user plane tunnel between the access network device and the user plane network element.

[0197] For example, the core network tunnel information includes a tunnel endpoint identifier (TEID) and address information of the user plane network element, and the access network tunnel information includes a TEID and address information of the access network device. It can be understood that the TEID in the core network tunnel information and the TEID in the access network tunnel information can be different, corresponding to the two ends of the user plane tunnel respectively.

[0198] Transmission of core network tunnel information

[0199] In some implementations, the core network network element in the embodiments of the present application further includes a user plane network element, and the session-related information carried in the IP packet further includes: core network tunnel information sent by the user plane network element to the access network device, and session management SM information sent by the session management network element to the access network device in addition to the core network tunnel information; or, SM information sent by the session management network element to the access network device, including the core network tunnel information.

[0200] That is, the core network tunnel information can be sent by a session management network element, e.g., SMF, to an access network device. For example, the session management network element sends the core network tunnel information to the access network device together with other SM information, e.g., including QoS profile and corresponding QFI, session identifier, slice information associated with the session, user plane security enforcement information, etc., and possibly including user plane network element related information, after receiving the core network tunnel information from a user plane network element. Alternatively, the core network tunnel information can be sent by a user plane network element, e.g., UPF, directly to an access network device. For the latter, the user plane network element needs to know the related information of the access network device, e.g., address information of the access network device, so as to be able to send an IP packet carrying the core network tunnel information directly to the access network device.

[0201] To this end, in some implementations, a session management network element can send access network device related information to a user plane network element, e.g., including one or more of the following: address information of the access network device; identifier information of the terminal device; session identifier. The access network device related information is used by the user plane network element to send core network tunnel information to the access network device. In this way, the user plane network element can send the core network tunnel information directly to the access network device based on the access network device related information, e.g., address information of the access network device, etc.

[0202] Optionally, if redundant transmission is adopted, the user plane network element can allocate two core network tunnel information for this session, and indicate that one of the core network tunnel information is for a redundant tunnel.

[0203] Transmission of access network tunnel information

[0204] In some implementations, the core network network element in the embodiments of the present application further includes a user plane network element, and the session related information carried in the IP packet further includes: SM information sent by the access network device to the session management network element in addition to the access network tunnel information, and access network tunnel information sent by the access network device to the user plane network element; or SM information sent by the access network device to the session management network element including the access network tunnel information.

[0205] That is, after the access network device establishes the necessary access network resources for the session with the terminal device and allocates the corresponding access network tunnel information, the access network tunnel information can be sent to the session management network element, such as the SMF, together with other SM information, such as the session identifier, the list of accepted / rejected QFI(s), the user plane enforcement policy notification, the established QoS flow status (for example, activated or inactivated), and the like, and sent by the session management network element to the user plane network element, such as the UPF. Alternatively, the access network device can directly send the access network tunnel information to the user plane network element. For the latter, the access network device needs to know the relevant information of the user plane network element, such as the address information of the user plane network element, so as to be able to directly send the IP packet carrying the access network tunnel information to the user plane network element.

[0206] To this end, in some implementations, the session-related information carried in the IP packet can further include user plane network element-related information sent by the session management network element or the user plane network element to the access network device, such as one or more of the following: type information of the user plane network element; address information of the user plane network element; and identifier information of the user plane network element. The user plane network element-related information is used by the access network device to send the access network tunnel information to the user plane network element. The session management network element or the user plane network element can send the user plane network element-related information to the access network device in the IP packet. In this way, the access network device can directly send the access network tunnel information to the user plane network element based on the user plane network element-related information, such as the address information of the user plane network element.

[0207] Embodiment 3 is described in more detail below in conjunction with FIGS. 10 and 11, which are examples of the user plane path establishment process in the establishment process of a PDU session. It is assumed that both the terminal device and the access network device can communicate with the core network element based on the IP packet in a point-to-point manner, and the signaling interaction in the user plane path establishment is shown in FIG. 10 or FIG. 11.

[0208] Referring to FIG. 10, in the flow of the user plane path establishment shown in FIG. 10, the core network tunnel information and the access network tunnel information exchanged between the terminal device and the user plane network element are forwarded by the SMF.

[0209] In step 1001, the SMF initiates a N4 session establishment procedure or a N4 session modification procedure, and obtains the core network tunnel information from the UPF.

[0210] The core network tunnel information includes, for example, a TEID and an IP address of the UPF used for the PDU session on the N3 / N9 tunnel. In addition, the UPF can also provide its IP address to the SMF.

[0211] In step 1002, the SMF sends SM information to the access network device.

[0212] At the same time, the aforementioned PDU session accept message can also be sent to the access network device.

[0213] The SM information includes, for example, one or more of the following: core network tunnel information, QoS attribute and corresponding QFI session identifier, slice information associated with the session, user plane security execution information. In addition, the SM information can also include UPF-related information, such as address information of the UPF, type information of the UPF, and identifier information of the UPF (in the case of multiple UPFs).

[0214] In step 1003, the access network device sends the PDU session accept message and the corresponding PDU session identifier to the terminal device, and establishes necessary access network-specific resources for the PDU session with the terminal device.

[0215] In step 1004, the access network device allocates access network tunnel information, and sends the SM information carrying the access network tunnel information directly to the SMF.

[0216] The access network tunnel information includes address information and a TEID of the access network. If the access network device receives two core network tunnel information, it also needs to allocate two access network tunnel information. The SM information includes, for example, access network tunnel information, session identifier, list of accepted and / or rejected QFIs, user plane execution policy notification, established QoS flow state (such as activated or not activated), etc.

[0217] In step 1005, the SMF sends the access network tunnel information to the UPF.

[0218] If the access network device obtains the address information of the corresponding UPF, it can also send the access network tunnel information directly to the UPF in an IP data packet.

[0219] Referring to FIG. 11, in the flow of user plane path establishment shown in FIG. 11, the terminal device and the user plane network element can directly interact the core network tunnel information and the access network tunnel information based on IP packets.

[0220] In step 1101, the SMF requests the UPF to allocate the core network tunnel information for the corresponding PDU session, and provides the access network device related information to the UPF.

[0221] The access network device related information, for example, includes one or more of the following: address information of the access network device; identification information of the terminal device; session identification.

[0222] In step 1102, the SMF sends the SM information other than the core network tunnel information to the access network device.

[0223] In addition, the SMF can simultaneously instruct the core network tunnel information to be sent directly by the UPF to the access network device. The access network tunnel information, for example, includes TEID and IP address of the UPF used for the PDU session on the N3 / N9 tunnel.

[0224] In addition, the SMF can also provide the access network device with UPF related information such as address information of the UPF, identification information of the UPF, etc.

[0225] In step 1103, the UPF directly sends the core network tunnel information to the access network device.

[0226] In addition, the UPF can also provide the access network device with PDU session identification, core network tunnel information for redundant transmission, network element type (used to indicate which network element this message comes from, here the UPF), address information of the UPF, identification information of the UPF. Here, the address information of the UPF can be provided to the access network device as the source address information in the packet header of the IP packet.

[0227] In step 1104, the access network device allocates the access network tunnel information.

[0228] The access network tunnel information, for example, includes address information of the access network device and TEID.

[0229] In step 1105, the access network device sends the SM information other than the access network tunnel information to the SMF.

[0230] In step 1106, the access network device directly sends the access network tunnel information to the UPF.

[0231] The access network tunnel information can be carried by the payload of the IP packet. The address information of the UPF can be provided by the SMF in step 1102 or by the UPF in step 1103.

[0232] In a conventional interaction process, such as the PDU session establishment process shown in FIG. 2, tunnel information needs to be forwarded between the access network device and the UPF through the AMF, and QoS parameters, session identifiers, user plane security execution information, congestion monitoring, and other information sent by the SMF to the access network device also need to be forwarded. In addition, SM information sent by the SMF to the terminal device also needs to be forwarded. In Embodiment 3, the SMF can directly interact with the access network device serving the terminal device, further reducing the signaling load of the AMF, reducing the number of nodes through which the signaling message is transmitted in the network, and reducing the transmission delay.

[0233] Embodiment 4

[0234] Embodiment 4 relates to a session handover process in which a terminal device is handed over from a source access network device (S-RAN) to a target access network device (T-RAN). After successful handover, the target access network device needs to update the mapping relationship (or association relationship) between the address information of the terminal device and the address information of the target access network device to other core network elements. The transmission of this information can also be based on IP packets.

[0235] The signaling interaction between the terminal device and the core network element is based on IP packets, and the access network device can be regarded as a router carrying IP packets between the terminal device and the core network element to some extent; or in other words, there is an IP router between the access network device and the core network element, which can send the data packet sent by the core network to the terminal device to the access network device serving the terminal device, or forward the data packet sent by the terminal device to the core network to the target core network element.

[0236] As can be seen, for mobile terminate (MT) messages (i.e., messages sent by the core network element to the terminal device), the core network element needs to first send them to the access network device serving the terminal device, and then send them to the terminal device by the access network device. Therefore, after the terminal device is successfully handed over from the source access network device to the target core network element, the mapping relationship between the address of the terminal device and the address of the access network device serving the terminal device needs to be provided to the core network element.

[0237] In some implementations, the wireless access device in the embodiments of the present application includes a target access network device in a session handover process, and the session-related information carried in the IP packet can include mapping relationship information between the terminal device and the target access network device sent by the target access network device to the core network element after the terminal device is successfully handed over to the access network device in the session handover.

[0238] The mapping relationship information includes, for example, one or more of the following: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

[0239] In some implementations, the mapping relationship information includes the following cases:

[0240] In a case where no reselection of the core network element occurs in the session switching process, the mapping relationship information includes mapping relationship information sent by the access network device to all core network elements serving the terminal device, such as AMF, SMF, PCF, NRF, UDM, AUSF, and the like; or,

[0241] In a case where reselection of the core network element occurs in the session switching process, the mapping relationship information includes mapping relationship information sent by the access network device to the reselected core network element; or,

[0242] The mapping relationship information includes mapping relationship information sent by the access network device to a target core network element, which can be, for example, a network element for storing context information and / or registration information of the terminal device, and the target network element has a function of providing other network elements with the mapping relationship information.

[0243] The target core network element includes, but is not limited to, AMF, UDM, NRF, and the like. When other core network elements have MT messages to be sent to the terminal device, the address information of the access network device serving the terminal device can be queried from the target core network element.

[0244] In some implementations, the wireless access device in the embodiment of the present application further includes a terminal device, and the session-related information carried in the IP packet further includes core network element-related information sent by the reselected core network element to the terminal device. The core network element-related information is used for the terminal device and the core network element to send and / or receive IP packets, and can include, for example, one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device; address information of the reselected core network element; and type information of the reselected core network element.

[0245] It should be noted that in some scenarios, the target access network device can have obtained the address information of the terminal device during the switching process; and in other scenarios, the terminal device can not actively provide its address information to the target access network device serving the terminal device, and in this case, the access network device needs to obtain the address information of the terminal device from the terminal device, or from a network element such as UDM that stores the identification information of the terminal device and the mapping relationship information.

[0246] In some implementations, the core network element related information sent by the core network element after reselection to the terminal device can be carried in the payload of an IP data packet, and the address information of the terminal device and the address information of the access network device are carried in the header of the IP data packet.

[0247] Embodiment 4 will be described in more detail below in conjunction with FIG. 12. As an example, FIG. 12 is an operation after the success of the handover procedure for a PDU session. It is assumed that the terminal device and the access network device can perform point-to-point communication with the core network element based on IP data packets, and the signaling interaction after the success of the PDU handover is shown in FIG. 12.

[0248] In step 1201, the terminal device is successfully handed over from the source access network device to the target access network device.

[0249] In step 1202, after the success of the handover procedure, the terminal device can send its identification information, address information, etc. to the target access network device, so that the access network device forwards the data packets belonging to the terminal device to the terminal device.

[0250] The identification information of the terminal device can be, for example, the AS layer identification of the terminal device, such as RNTI, 5G-TMSI, etc., or the NAS layer identification of the terminal device, such as SUCI, GUTI, etc. The address information of the terminal device can be, for example, an IPv6 address, an IPv4 address, or a MAC layer address.

[0251] In step 1203, the target access network device sends the mapping relationship information between the terminal device and the access network device to the core network element.

[0252] The mapping relationship information includes, for example, the address information of the terminal device, the identification information of the terminal device, and the address information and identification information of the access network device serving the terminal device.

[0253] Here, the following three cases can be included:

[0254] Step 1203a), during the handover procedure, no reselection of the core network element occurs, and the target access network device provides the address information of the terminal device and the address information of the access network device serving the terminal device to all core network elements serving the terminal device, including, for example, AMF, SMF, PCF, NRF, UDM, AUSF, etc.

[0255] Step 1203b), during the handover procedure, reselection of the core network element occurs, and the target access network device provides the address information of the terminal device and the address information of the access network device serving the terminal device to the reselected core network element.

[0256] Step 1203c), the target access network device only provides the address information of the terminal device and the address information of the access device serving the terminal device to the target core network element for storing the terminal device context and registration information, such as AMF, UDM or NRF. When other core network elements have MO messages to be sent to the terminal device, the address information of the access device serving the terminal device can be queried from the target core network element.

[0257] In the figure 12, NF represents all possible core network elements serving the terminal device, and T-NF represents the target core network element after the core network element reselection.

[0258] The information to be provided to the above-mentioned core network element includes, for example, the following parameters: identification information of the terminal device; address information of the terminal device; address information of the access network device; identification information of the access network device.

[0259] In step 1204, in the corresponding scenario of step 1203b), after obtaining the address information of the terminal device and the address information of the access network device serving the terminal device, the target core network element can send the core network element related information to the terminal device.

[0260] The core network element related information includes, for example, one or more of the following: terminal device identification information; type information of the core network element; address information of the core network element. These information can be carried in the payload of the IP packet, and the address information of the access device and the address information of the terminal device are included in the packet header of the IP packet.

[0261] After the handover is completed, the core network element is informed that the access network device serving the terminal device has changed, which can effectively avoid the core network element sending downlink signaling to the source access network device, resulting in that the MT signaling cannot be sent to the terminal device or is delayed to be sent to the terminal device. In addition, providing the address information of the reselected core network element to the terminal device can also avoid the terminal device sending uplink signaling message to the old core network element, resulting in that the mobile originated (MO) signaling (i.e. the message sent by the terminal device to the core network element) is delayed to reach the target core network element or cannot reach the target core network element.

[0262] Embodiment 5

[0263] Embodiment 5 relates to a reselection procedure of a core network element caused by session switching or other reasons such as load balancing, etc. In the case of session switching or core network element switching caused by load balancing, etc., the old core network element (i.e., source core network element (target NF, T-NF)) needs to migrate the address information of the terminal device, etc. to the new core network element (i.e., target core network element (target NF, T-NF)) and provide the address information of the new core network element to the terminal device before deleting the context of the terminal device retained, or trigger the new core network element to issue its address information to the terminal device. The transmission of these information can also be based on IP packets.

[0264] In some implementations, the session-related information carried in the IP packet can include reselection indication information sent by the source core network element or the target core network element to the terminal device in the case of reselection of the core network element. The reselection indication information is used to indicate the switching from the source core network element to the target core network element.

[0265] As an example, the IP packet carrying the reselection indication information can be based on a two-layer protocol stack such as IP in IP, etc., the address of the terminal device is included as the destination address in the inner packet header of the IP packet, and the address of the access network device serving the terminal device is included as the destination address in the outer packet header of the IP packet. The reselection indication information can be carried in the payload of the IP packet and can carry one or more of the following information: identification information of the terminal device; information indicating that the core network element has been reselected; address information of the target core network element; type information of the target core network element.

[0266] In some implementations, the source core network element needs to migrate the context information of the terminal device to the target core network element, and the context information of the terminal device migrated by the source core network element to the target core network element can include one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device.

[0267] In some scenarios, the core network element can not indicate the address information of the target core network element to the terminal device, but only notify the terminal device that the core network element has been reselected (NF relocation), and only when the target core network element has MT messages to send to the terminal device, the address information of the target core network element is provided to the terminal device. During this period, if the terminal device has new MO messages to send to the target core network element, the address information of the target core network element needs to be requested from a network element such as NRF, etc.

[0268] Embodiment 5 will be described in more detail below in conjunction with FIG. 13. As an example, FIG. 13 is an operation after the core network element reselection. It is assumed that the terminal device and the access network device can communicate with the core network element based on IP packets in a point-to-point manner, and the signaling interaction after the core network element reselection is shown in FIG. 13.

[0269] In step 1301, the core network element performs load balancing and offloads the service of the terminal device to the target core network element.

[0270] In step 1302, the core network element such as AMF, SMF, etc. migrates the context information of the terminal device to the target core network element.

[0271] The context information of the terminal device includes, for example, the identification information of the terminal device, the address information of the terminal device, and the address information of the access network device serving the terminal device.

[0272] In step 1303, the source core network element or the target core network element sends the reselection indication information to the terminal device.

[0273] Here, the following two cases can be included:

[0274] In step 1303a), the source core network element sends the reselection indication information to the terminal device.

[0275] In step 1303b), the target core network element sends the reselection indication information to the terminal device.

[0276] The reselection indication information includes, for example, the identification information of the terminal device, information indicating that the core network element reselection, the address information of the target core network element, and the type information of the target core network element.

[0277] In embodiment 5, after the core network element reselection, the address information of the new core network element saved by the terminal device is updated, which can avoid the MO signaling delay to reach the new core network element or unable to reach the new core network element when the terminal device sends the MO signaling to the old core network element which no longer serves it.

[0278] It should be noted that the above examples of FIGS. 8-13 are only to help those skilled in the art understand the embodiments of the present application, and are not intended to limit the embodiments of the present application to the specific values or specific scenarios exemplified. Those skilled in the art can obviously make various equivalent modifications or changes based on the examples of FIGS. 8-13, and such modifications or changes also fall within the scope of the embodiments of the present application.

[0279] In the embodiments of the present application, the session-related information between the core network element and the terminal device and the access network device can be carried in the IP data packet for sending and / or receiving, so that the AMF can be decoupled from the session management operation and exist independently as an access and mobility management network element without forwarding and aggregating signaling or messages between other core network elements and the terminal device and the access network device, thereby reducing the signaling load of the AMF and the upgrade and maintenance cost.

[0280] The method embodiments of the present application are described in detail above in combination with FIGS. 7 to 13, and the device embodiments of the present application are described in detail below in combination with FIGS. 14 to 16. It should be understood that the description of the method embodiments corresponds to the description of the device embodiments, and therefore, the parts not described in detail can be referred to the foregoing method embodiments.

[0281] FIG. 14 is a structural schematic diagram of a wireless access device provided by the embodiments of the present application. The wireless access device 1400 shown in FIG. 14 can include a transceiver unit 1410. The transceiver unit 1410 is configured to send an IP data packet to a core network element and / or receive an IP data packet sent by the core network element, wherein the core network element is a session-related network element, and the session-related information is carried in the IP data packet.

[0282] In some implementations, the wireless access device includes a terminal device, the core network element includes a session management network element, and the session-related information includes: a session request message sent by the terminal device to the session management network element; and / or a session response message received by the terminal device from the session management network element and corresponding to the session request message, wherein the session response message includes a session accept message or a session reject message.

[0283] In some implementations, the session request message is a session establishment request message, and the session response message is a session establishment response message corresponding to the session establishment request message; or the session request message is a session modification request message, and the session response message is a session modification response message corresponding to the session modification request message; or the session request message is a session release request message, and the session response message is a session release response message corresponding to the session release request message.

[0284] In some implementations, the session request message further includes one or more of the following: an identifier of a session to be established; an identifier of a session to be released; an S-NSSAI; a DNN; a type of the session request message; an SSC mode; address information of the terminal device; and identification information of the terminal device.

[0285] In some implementations, the address information of the terminal device is carried in a packet header of the IP data packet as a source address of the IP data packet.

[0286] In some embodiments, the session accept message comprises one or more of: a session identifier; information indicating acceptance of the session request; a session type; an SSC mode; an S-NSSAI; a QoS rule; a session address allocated to the session of the terminal device.

[0287] In some embodiments, the session reject message comprises one or more of: a session identifier; information indicating rejection of the session request; a reason for rejecting the session request.

[0288] In some embodiments, the transceiver 1410 is further configured to obtain, from a network storage function (NRF), session management network element related information, the session management network element related information being used for the terminal device to send the session request message to the session management network element.

[0289] In some embodiments, the core network network element comprises the NRF, and the session related information further comprises: a network element information request message sent by the terminal device to the NRF; and / or, a network element information response message sent by the NRF to the terminal device in response to the network element information request message, the network element information response message carrying the session management network element related information.

[0290] In some embodiments, the network element information request message comprises one or more of: identification information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; an S-NSSAI; a DNN; an access type of the session.

[0291] In some embodiments, the session management network element related information comprises one or more of: identification information of the terminal device; type information of the session management network element; address information of the session management network element; identification information of the session management network element.

[0292] In some embodiments, the session related information further comprises: a session authentication command message received by the terminal device from the session management network element, the session authentication command message carrying EAP request information sent by a DN-AAA; and / or, a session authentication completion message sent by the terminal device to the session management network element, the session authentication completion message carrying EAP response information; wherein the EAP request information and the EAP response information are used for secondary authentication of the terminal device.

[0293] In some embodiments, the session authentication command and / or the session authentication completion message further carries information of a data network specific identity.

[0294] In some embodiments, the wireless access device further comprises an access network device, the session-related information further comprises: core network tunnel information received by the access network device from the core network element; and / or, access network tunnel information sent by the access network device to the core network element; wherein the core network tunnel information and the access network tunnel information are used to establish a user plane tunnel between the access network device and a user plane element, the core network tunnel information comprises a TEID and address information of the user plane element, and the access network tunnel information comprises a TEID and address information of the access network device.

[0295] In some embodiments, the core network element further comprises the user plane element, and the session-related information comprises: the core network tunnel information received by the access network device from the user plane element, and session management (SM) information received by the access network device from the session management element other than the core network tunnel information; or, SM information received by the access network device from the session management element, which comprises the core network tunnel information.

[0296] In some embodiments, the session-related information comprises: SM information sent by the access network device to the session management element other than the access network tunnel information, and the access network tunnel information sent by the access network device to the user plane element; or, SM information sent by the access network device to the session management element, which comprises the access network tunnel information.

[0297] In some embodiments, the session-related information further comprises: user plane element-related information received by the access network device from the session management element or the user plane element, the user plane element-related information being used for the access network device to send the access network tunnel information to the user plane element.

[0298] In some embodiments, the user plane element-related information comprises one or more of the following: type information of the user plane element; address information of the user plane element; and identification information of the user plane element.

[0299] In some embodiments, access network device-related information is sent by the session management element to the user plane element, the access network device-related information being used for the user plane element to send the core network tunnel information to the access network device.

[0300] In some embodiments, the access network-related information comprises one or more of the following: address information of the access network device; identification information of the terminal device; and session identification.

[0301] In some embodiments, the wireless access device comprises a target access network device in a session handover process, and the session-related information comprises mapping relationship information between the terminal device and the target access network device sent by the target access network device to the core network element after the terminal device successfully switches to the target access network device in the session handover, wherein the mapping relationship information comprises one or more of the following: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

[0302] In some embodiments, the mapping relationship information comprises: in a case where no reselection of the core network element occurs in the session handover process, the mapping relationship information sent by the access network device to all core network elements serving the terminal device; or in a case where reselection of the core network element occurs in the session handover process, the mapping relationship information sent by the access network device to the reselected core network element; or the mapping relationship information sent by the access network device to a target core network element, wherein the target core network element is configured to store context information and / or registration information of the terminal device and has a function of providing other elements with a query of the mapping relationship information.

[0303] In some embodiments, the wireless access device further comprises the terminal device, and the session-related information further comprises core network element-related information received by the terminal device from the reselected core network element, wherein the core network element-related information is used for transmission and / or reception of IP data packets between the terminal device and the core network element.

[0304] In some embodiments, the core network element-related information comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device; address information of the reselected core network element; and type information of the reselected core network element.

[0305] In some embodiments, the core network element-related information is carried in a payload of an IP data packet, and address information of the terminal device and address information of the access network device are carried in a packet header of the IP data packet.

[0306] In some embodiments, the session-related information comprises reselection indication information received by the terminal device from a source core network element or a target core network element in a case where reselection of the core network element occurs, wherein the reselection indication information is used to indicate switching from the source core network element to the target core network element.

[0307] In some embodiments, the handover indication information comprises one or more of the following: identification information of the terminal device; information indicating that the core network element reselects; address information of the target core network element; type information of the target core network element.

[0308] In some embodiments, the context information of the terminal device migrated by the source core network element to the target core network element comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of an access network device.

[0309] It can be understood that the transceiver unit 1410 may, for example, be the transceiver 1630. In addition, the wireless access device 1400 optionally further comprises a processor 1610 and a memory 1620, as shown in FIG. 16.

[0310] FIG. 15 is a structural diagram of a core network device according to an embodiment of the present application. The core network device 1500 shown in FIG. 15 can comprise a transceiver unit 1510. The transceiver unit 1510 is configured to receive an IP packet sent by a wireless access device and / or send an IP packet to the wireless access device, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

[0311] In some embodiments, the wireless access device comprises a terminal device, the core network element comprises a session management network element, and the session-related information comprises: a session request message received by the session management network element from the terminal device; and / or a session response message sent by the session management network element to the terminal device in response to the session request message, wherein the session response message comprises a session acceptance message or a session rejection message.

[0312] In some embodiments, the session request message is a session establishment request message, and the session response message is a session establishment response message in response to the session establishment request message; or the session request message is a session modification request message, and the session response message is a session modification response message in response to the session modification request message; or the session request message is a session release request message, and the session response message is a session release response message in response to the session release request message.

[0313] In some embodiments, the session request message further comprises one or more of the following: identification of a session to be established; identification of a session to be released; S-NSSAI; DNN; type of the session request message; SSC mode; address information of the terminal device; identification information of the terminal device.

[0314] In some embodiments, the address information of the terminal device is carried in a packet header of the IP packet as a source address of the IP packet.

[0315] In some embodiments, the session accept message comprises one or more of the following: a session identifier; information indicating acceptance of the session request; a session type; an SSC mode; an S-NSSAI; a QoS rule; a session address allocated to the session of the terminal device.

[0316] In some embodiments, the session reject message comprises one or more of the following: a session identifier; information indicating rejection of the session request; a reason for rejecting the session request.

[0317] In some embodiments, the session request message is sent by the terminal device based on session management network element related information, and the session management network element related information is obtained from an NRF.

[0318] In some embodiments, the core network network element comprises the NRF, and the session related information further comprises: a network element information request message sent by the terminal device to the NRF; and / or, a network element information response message sent by the NRF to the terminal device in response to the network element information request message, and the session management network element related information is carried in the network element information response message.

[0319] In some embodiments, the network element information request message comprises one or more of the following: identification information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; an S-NSSAI; a DNN; an access type of the session.

[0320] In some embodiments, the session management network element related information comprises one or more of the following: identification information of the terminal device; type information of the session management network element; address information of the session management network element; identification information of the session management network element.

[0321] In some embodiments, the core network device further comprises a processing unit, and the transceiver 1510 is further configured to obtain subscription data of the terminal device from a UDM; and the processing unit is configured to determine whether to receive or reject the session request message based on the subscription data.

[0322] In some embodiments, if the DNN carried in the session request message is a LADN, the processing unit is further configured to: obtain a service area of the LADN, and determine whether the terminal device is located in the service area of the LADN; wherein the service area of the LADN can be obtained based on one or more of the following: from the AMF; from the UDM; from a local configuration.

[0323] In some embodiments, the session-related information further includes: a session authentication command message sent by the session management network element to the terminal device, the session authentication command message carrying EAP request information sent by the DN-AAA; and / or, a session authentication completion message received by the session management network element from the terminal device, the session authentication completion message carrying EAP response information; wherein the EAP request information and the EAP response information are used for secondary authentication of the terminal device.

[0324] In some embodiments, the session authentication command and / or the session authentication completion message further carries information of a data network specific identity.

[0325] In some embodiments, the transceiver 1510 is further configured to perform one or more of the following steps: the session management network element receives the EAP request information sent by the DN-AAA; the session management network element sends the EAP response information to the DN-AAA; the session management network element receives an authentication success message or an authentication failure message sent by the DN-AAA.

[0326] In some embodiments, the wireless access device further includes an access network device, and the session-related information further includes: core network tunnel information sent by the core network network element to the access network device; and / or, access network tunnel information received by the core network network element from the access network device; wherein the core network tunnel information and the access network tunnel information are used to establish a user plane tunnel between the access network device and a user plane network element, the core network tunnel information includes a TEID and address information of the user plane network element, and the access network tunnel information includes a TEID and address information of the access network device.

[0327] In some embodiments, the core network network element further includes the user plane network element, and the session-related information includes: the core network tunnel information sent by the user plane network element to the access network device, and session management (SM) information sent by the session management network element to the access network device in addition to the core network tunnel information; or, SM information including the core network tunnel information sent by the session management network element to the access network device.

[0328] In some embodiments, the session-related information comprises: SM information received by the session management network element from the access network device, except for the access network tunnel information, and the access network tunnel information received by the user plane network element from the access network device; or the SM information received by the session management network element from the access network device, including the access network tunnel information.

[0329] In some embodiments, the session-related information further comprises: user plane network element-related information sent by the session management network element or the user plane network element to the access network device, the user plane network element-related information being used for the access network device to send the access network tunnel information to the user plane network element.

[0330] In some embodiments, the user plane network element-related information comprises one or more of: type information of the user plane network element; address information of the user plane network element; identification information of the user plane network element.

[0331] In some embodiments, the access network device-related information is sent by the session management network element to the user plane network element, and the access network device-related information is used for the user plane network element to send the core network tunnel information to the access network device.

[0332] In some embodiments, the access network-related information comprises one or more of: address information of the access network device; identification information of the terminal device; session identification.

[0333] In some embodiments, the transceiver 1510 is further configured to: in a case where the session request is accepted, register with the UDM, wherein information recorded by the UDM after the registration comprises address information of the terminal device and / or session address.

[0334] In some embodiments, the wireless access device comprises a target access network device in a session switching process, and the session-related information comprises: mapping relationship information between the terminal device and the target access network device received by the core network network element from the target access network device after the session switching is performed and the terminal device is successfully switched to the access network device, wherein the mapping relationship information comprises one or more of: identification information of the terminal device; identification information of the access network device; address information of the terminal device; address information of the access network device.

[0335] In some embodiments, the mapping relationship information comprises: in a case where no reselection of the core network element occurs in the session switching process, the mapping relationship information received by all core network elements serving the terminal device from the target access network device; or, in a case where reselection of the core network element occurs in the session switching process, the mapping relationship information received by the reselected core network element from the target access network device; or, the mapping relationship information received by a target core network element from the target access network device, wherein the target core network element is configured to store context information and / or registration information of the terminal device and has a function of providing other network elements with a query of the mapping relationship information.

[0336] In some embodiments, the wireless access device further comprises the terminal device, and the session-related information further comprises: core network element-related information sent by the reselected core network element to the terminal device, the core network element-related information being used for transmission and / or reception of IP data packets between the terminal device and the core network element.

[0337] In some embodiments, the core network element-related information comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device; address information of the reselected core network element; type information of the reselected core network element.

[0338] In some embodiments, the core network element-related information is carried in a payload of an IP data packet, and the address information of the terminal device and the address information of the access network device are carried in a packet header of the IP data packet.

[0339] In some embodiments, the session-related information comprises: reselection indication information sent by a source core network element or a target core network element to the terminal device in a case where reselection of the core network element occurs, the reselection indication information being used to indicate switching from the source core network element to the target core network element.

[0340] In some embodiments, the switching indication information comprises one or more of the following: identification information of the terminal device; information indicating reselection of the core network element; address information of the target core network element; type information of the target core network element.

[0341] In some embodiments, the context information of the terminal device migrated from the source core network element to the target core network element comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device.

[0342] It can be understood that the transceiver unit 1510 can be the transceiver 1630, for example. In addition, the core network device 1500 can further include the processor 1610 and the memory 1620, as shown in FIG. 16.

[0343] FIG. 16 is a schematic structural diagram of an apparatus for communication to which embodiments of the present application can be applied. The dashed line shown in FIG. 16 indicates that the unit or module is optional. The apparatus 1600 can be used to implement the methods described in the above method embodiments. The apparatus 1600 can be a chip, a wireless access device or a core network device, for example, which includes a terminal device and / or an access network device.

[0344] The apparatus 1600 can include one or more processors 1610. The processor 1610 can support the apparatus 1600 to implement the methods described in the foregoing method embodiments. The processor 1610 can be a general purpose processor or a dedicated processor. For example, the processor 1610 can be a central processing unit (CPU). Alternatively, the processor 1610 can also be other general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, etc. The general purpose processor can be a microprocessor or can be any conventional processor.

[0345] The apparatus 1600 can further include one or more memories 1620. The memory 1620 stores programs, which can be executed by the processor 1610, so that the processor 1610 performs the methods described in the foregoing method embodiments. The memory 1620 can be independent of the processor 1610 or can be integrated in the processor 1610.

[0346] The apparatus 1600 can further include a transceiver 1630. The processor 1610 can communicate with other devices or chips through the transceiver 1630. For example, the processor 1610 can perform data transceiving with other devices or chips through the transceiver 1630.

[0347] Embodiments of the present application further provide a communication system. The communication system includes the wireless access device or the core network device described above. In some implementations, the system further includes other devices that interact with the wireless access device or the core network device.

[0348] The embodiment of the present application further provides a computer readable storage medium for storing a program. The computer readable storage medium can be applied to the wireless access device or the core network device provided by the embodiment of the present application, and the program causes the computer to execute the method performed by the wireless access device or the core network device in the various embodiments of the present application.

[0349] The embodiment of the present application further provides a computer program product. The computer program product includes a program. The computer program product can be applied to the wireless access device or the core network device provided by the embodiment of the present application, and the program causes the computer to execute the method performed by the wireless access device or the core network device in the various embodiments of the present application.

[0350] The embodiment of the present application further provides a computer program. The computer program can be applied to the wireless access device or the core network device provided by the embodiment of the present application, and the computer program causes the computer to execute the method performed by the wireless access device or the core network device in the various embodiments of the present application.

[0351] It should be understood that the terms "system" and "network" can be used interchangeably in the present application. In addition, the terms used in the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. The terms "first", "second", "third", and "fourth" and the like in the specification and claims of the present application and the drawings are used to distinguish different objects, and are not used to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0352] In the embodiments of the present application, the "indication" mentioned can be direct indication, indirect indication, or can be an indication with an associated relationship. For example, A indicates B, which can mean that B can be obtained by A; or A indirectly indicates B, for example, A indicates C, and B can be obtained by C; or A and B have an associated relationship.

[0353] In the embodiments of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean that B is determined only according to A, but B can also be determined according to A and / or other information.

[0354] In the embodiments of the present application, the term "corresponding" can mean that there is a direct or indirect corresponding relationship between the two, or can mean that there is an associated relationship between the two, or can mean an indication and being indicated, configuration and being configured, and the like.

[0355] In embodiments of the present application, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables or other means for indicating relevant information in a device (for example, including a wireless access device or a core network device), and the present application does not limit the specific implementation manner. For example, the predefinition can refer to definition in a protocol.

[0356] In embodiments of the present application, the "protocol" can refer to a standard protocol in the communication field, for example, can include the LTE protocol, the NR protocol and the related protocol applied in the future communication system, and the present application does not limit this.

[0357] In embodiments of the present application, the term "and / or" is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0358] The "information X received by device A from device B" in embodiments of the present application can also be described as "information X sent by device B to device A".

[0359] In various embodiments of the present application, the size of the serial number of the above processes does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0360] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented by other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there can be another division way in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection between each other can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0361] The units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiments of the present application.

[0362] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0363] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented 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, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as digital video disc (DVD)) or semiconductor media (such as solid state disk (SSD)) and the like.

[0364] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of wireless communication, comprising: Comprising: The wireless access device sends an Internet Protocol (IP) packet to a core network element and / or receives an IP packet sent by the core network element, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

2. The method of claim 1, wherein, The wireless access device comprises a terminal device, and the core network element comprises a session management network element, and the session-related information comprises: a session request message sent by the terminal device to the session management network element; and / or a session response message received by the terminal device from the session management network element and corresponding to the session request message, wherein the session response message comprises a session accept message or a session reject message.

3. The method of claim 2, wherein: the session request message is a session establishment request message, and the session response message is a session establishment response message corresponding to the session establishment request message; or the session request message is a session modification request message, and the session response message is a session modification response message corresponding to the session modification request message; or the session request message is a session release request message, and the session response message is a session release response message corresponding to the session release request message.

4. The method of claim 3, wherein, The session request message further comprises one or more of the following: an identifier of a session to be established; an identifier of a session to be released; single network slice selection assistance information (S-NSSAI); data network identification (DNN); a type of session request message; a session and service continuity (SSC) mode; address information of the terminal device; and identification information of the terminal device.

5. The method of claim 4, wherein, The address information of the terminal device is carried in a packet header of the IP packet as a source address of the IP packet.

6. The method according to any one of claims 2 to 5, characterized in that, The session accept message comprises one or more of the following: a session identifier; information indicating acceptance of a session request; a session type; an SSC mode; S-NSSAI; quality of service (QoS) rules; and a session address allocated to a session of the terminal device.

7. The method according to any one of claims 2 to 6, characterized in that, The session reject message comprises one or more of the following: a session identifier; information indicating rejection of a session request; a reason for rejecting a session request.

8. The method according to any one of claims 2 to 6, characterized in that, The method further comprises: The terminal device obtains session management network element-related information from a network repository function (NRF), wherein the session management network element-related information is used for the terminal device to send the session request message to the session management network element.

9. The method of claim 8, wherein, The terminal device obtains session management network element-related information from the NRF, comprising: the terminal device sends a network element information request message to the NRF; and / or the terminal device receives a network element information response message sent by the NRF and corresponding to the network element information request message, wherein the session management network element-related information is carried in the network element information response message; wherein the network element information request message and the network element information response message are carried in an IP packet.

10. The method of claim 9, wherein, The network element information request message comprises one or more of the following: identification information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; S-NSSAI; DNN; and An access type of the session.

11. The method according to claim 9 or 10, characterized in that, The session management network element related information comprises one or more of the following: Identity information of the terminal device; Type information of the session management network element; Address information of the session management network element; Identity information of the session management network element.

12. The method according to any one of claims 2 to 11, characterized in that, The session related information further comprises: A session authentication command message received by the terminal device from the session management network element, wherein the session authentication command message carries extensible authentication protocol (EAP) request information sent by a data network authentication authorization and accounting (DN-AAA); And / or a session authentication completion message sent by the terminal device to the session management network element, wherein the session authentication completion message carries EAP response information; The EAP request information and the EAP response information are used for secondary authentication of the terminal device.

13. The method of claim 12, wherein, The session authentication command and / or the session authentication completion message further carries information of a data network specific identity.

14. The method according to any one of claims 1 to 13, characterized in that, The wireless access device comprises an access network device, and the session related information comprises: Core network tunnel information received by the access network device from the core network network element; and / or Access network tunnel information sent by the access network device to the core network network element; The core network tunnel information and the access network tunnel information are used for establishing a user plane tunnel between the access network device and a user plane network element, the core network tunnel information comprises a tunnel endpoint identifier (TEID) and address information of the user plane network element, and the access network tunnel information comprises a TEID and address information of the access network device.

15. The method of claim 14, wherein, The core network network element further comprises the user plane network element, and the session related information comprises: The core network tunnel information received by the access network device from the user plane network element, and SM information received by the access network device from the session management network element other than the core network tunnel information; or SM information received by the access network device from the session management network element, which comprises the core network tunnel information.

16. The method of claim 14, wherein, The session related information comprises: SM information sent by the access network device to the session management network element other than the access network tunnel information, and the access network tunnel information sent by the access network device to the user plane network element; or SM information sent by the access network device to the session management network element, which comprises the access network tunnel information.

17. The method according to claim 15 or 16, characterized in that The session related information further comprises: User plane network element related information received by the access network device from the session management network element or the user plane network element, wherein the user plane network element related information is used for the access network device to send the access network tunnel information to the user plane network element.

18. The method of claim 17, wherein, The user plane network element related information comprises one or more of the following: Type information of the user plane network element; Address information of the user plane network element; Identity information of the user plane network element.

19. The method according to any one of claims 14 to 18, characterized in that, Access network device related information is sent by the session management network element to the user plane network element, wherein the access network device related information is used for the user plane network element to send the core network tunnel information to the access network device.

20. The method of claim 19, wherein, The access network related information comprises one or more of the following: address information of the terminal device; address information of the access network device; session identifier.

21. The method of any one of claims 1 to 20, wherein, The wireless access device comprises a target access network device in a session switching process, and the session-related information comprises: After performing session switching and successfully switching to the access network device, the target access network device sends mapping relationship information between the terminal device and the target access network device to the core network element, wherein the mapping relationship information comprises one or more of the following: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

22. The method of claim 21, wherein, The mapping relationship information comprises: In the case where no reselection of the core network element occurs in the session switching process, the access network device sends the mapping relationship information to all core network elements serving the terminal device; or, In the case where reselection of the core network element occurs in the session switching process, the access network device sends the mapping relationship information to the reselected core network element; or, The access network device sends the mapping relationship information to a target core network element, wherein the target core network element is used to store context information and / or registration information of the terminal device and has a function of providing other elements with query of the mapping relationship information.

23. The method of claim 22, wherein, The wireless access device further comprises the terminal device, and the session-related information further comprises: The terminal device receives core network element-related information from the reselected core network element, and the core network element-related information is used for sending and / or receiving IP data packets between the terminal device and the core network element.

24. The method of claim 23, wherein, The core network element-related information comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device; address information of the reselected core network element; type information of the reselected core network element.

25. The method of claim 23 or 24, wherein, The core network element-related information is carried in a payload of an IP data packet, and a packet header of the IP data packet carries address information of the terminal device and address information of the access network device.

26. The method of any one of claims 1 to 25, wherein, The session-related information comprises: In the case where reselection of the core network element occurs, the terminal device receives reselection indication information from a source core network element or a target core network element, and the reselection indication information is used to indicate switching from the source core network element to the target core network element.

27. The method of claim 26, wherein, The switching indication information comprises one or more of the following: identification information of the terminal device; information indicating reselection of the core network element; address information of the target core network element; type information of the target core network element.

28. The method of claim 26 or 27, wherein, Context information of the terminal device migrated from the source core network element to the target core network element comprises one or more of the following: identification information of the terminal device; address information of the terminal device; address information of the access network device.

29. A method of wireless communication, comprising: comprises: A core network element receives and / or sends an Internet Protocol (IP) packet to a wireless access device, wherein the core network element is a session-related network element, and the IP packet carries session-related information.

30. The method of claim 29, wherein, The wireless access device comprises a terminal device, and the core network element comprises a session management network element, and the session-related information comprises: a session request message received by the session management network element from the terminal device; and / or a session response message sent by the session management network element to the terminal device for the session request message, wherein the session response message comprises a session accept message or a session reject message.

31. The method of claim 30, wherein the session request message is a session establishment request message, and the session response message is a session establishment response message for the session establishment request message; or the session request message is a session modification request message, and the session response message is a session modification response message for the session modification request message; or the session request message is a session release request message, and the session response message is a session release response message for the session release request message. The session request message further comprises one or more of the following:

32. The method of claim 31, wherein, an identifier of a session to be established; an identifier of a session to be released; single network slice selection assistance information (S-NSSAI); data network identification (DNN); a type of session request message; a session and service continuity (SSC) mode; address information of the terminal device; and identification information of the terminal device. The address information of the terminal device is carried in a packet header of the IP packet as a source address of the IP packet.

33. The method of claim 32, wherein, The session accept message comprises one or more of the following:

34. The method of any one of claims 30-33, wherein, a session identifier; information indicating acceptance of a session request; a session type; an SSC mode; S-NSSAI; a quality of service (QoS) rule; and a session address allocated to a session of the terminal device. The session reject message comprises one or more of the following:

35. The method of any one of claims 30-34, wherein, a session identifier; information indicating rejection of a session request; a reason for rejecting a session request. The session request message is sent by the terminal device to the session management network element based on session management network element-related information, and the session management network element-related information is obtained from a network repository function (NRF).

36. The method of any one of claims 30-35, wherein, The following information in the process in which the terminal device obtains the session management network element-related information from the NRF is carried in an IP packet:

37. The method of claim 36, wherein, a network element information request message sent by the terminal device to the NRF; and / or a network element information response message received by the terminal device from the NRF for the network element information request message, wherein the session management network element-related information is carried in the network element information response message. The network element information request message comprises one or more of the following: identification information of the terminal device; 38. The method of claim 37, wherein, address information of the terminal device; type information of the session management network element; location information of the terminal device; S-NSSAI; DNN; and an access type of a session. ​ ​ 39. The method of claim 37 or 38, wherein, The session management network element related information comprises one or more of the following: The identity information of the terminal device; The type information of the session management network element; The address information of the session management network element; The identity information of the session management network element.

40. The method of any one of claims 30-39, wherein, The method further comprises: The session management network element acquires subscription data of the terminal device from a unified data management (UDM); The session management network element determines, based on the subscription data, whether to receive or reject the session request message.

41. The method of claim 40, wherein, If the DNN carried in the session request message is a local area data network (LADN), the method further comprises: The session management network element acquires a service area of the LADN and determines whether the terminal device is located within the service area of the LADN; The service area of the LADN can be acquired based on one or more of the following: from the AMF; from the UDM; from local configuration.

42. The method of any one of claims 30-41, wherein, The session related information further comprises: A session authentication command message sent by the session management network element to the terminal device, wherein the session authentication command message carries extensible authentication protocol (EAP) request information sent by a data network authentication, authorization and accounting (DN-AAA); and / or A session authentication completion message received by the session management network element from the terminal device, wherein the session authentication completion message carries EAP response information; The EAP request information and the EAP response information are used for secondary authentication of the terminal device.

43. The method of claim 42, wherein, The session authentication command and / or the session authentication completion message further carries information of a data network specific identity.

44. The method of claim 42 or 43, wherein, The method further comprises one or more of the following steps: The session management network element receives the EAP request information sent by the DN-AAA; The session management network element sends the EAP response information to the DN-AAA; The session management network element receives an authentication success message or an authentication failure message sent by the DN-AAA.

45. The method of any one of claims 29-44, wherein, The wireless access device comprises an access network device, and the session related information comprises: Core network tunnel information sent by the core network network element to the access network device; and / or Access network tunnel information received by the core network network element from the access network device; The core network tunnel information and the access network tunnel information are used for establishing a user plane tunnel between the access network device and a user plane network element, the core network tunnel information comprises a tunnel endpoint identifier (TEID) and address information of the user plane network element, and the access network tunnel information comprises a TEID and address information of the access network device.

46. The method of claim 45, wherein, The core network network element further comprises the user plane network element, and the session related information comprises: The core network tunnel information sent by the user plane network element to the access network device, and session management (SM) information sent by the session management network element to the access network device, other than the core network tunnel information; or SM information sent by the session management network element to the access network device, which comprises the core network tunnel information.

47. The method of claim 45 or 46, wherein, The session related information comprises: The SM information received by the session management network element from the access network device, in addition to the access network tunnel information, and the access network tunnel information received by the user plane network element from the access network device; or The SM information received by the session management network element from the access network device, including the access network tunnel information.

48. The method of claim 46 or 47, wherein, The session-related information further comprises: The user plane network element-related information sent by the session management network element or the user plane network element to the access network device, which is used for the access network device to send the access network tunnel information to the user plane network element.

49. The method of claim 48, wherein, The user plane network element-related information comprises one or more of: Type information of the user plane network element; Address information of the user plane network element; Identification information of the user plane network element.

50. The method of any one of claims 45-49, wherein, The access network device-related information is sent by the session management network element to the user plane network element, which is used for the user plane network element to send the core network tunnel information to the access network device.

51. The method of claim 50, wherein, The access network-related information comprises one or more of: Address information of the access network device; Identification information of the terminal device; Session identification.

52. The method of any one of claims 30-51, wherein, The method further comprises: In the case that the session request is accepted, the session management network element registers with a unified data management (UDM), wherein the information recorded by the UDM after registration comprises address information of the terminal device and / or session address.

53. The method of any one of claims 29-52, wherein, The wireless access device comprises a target access network device in a session switching process, and the session-related information comprises: After performing session switching and the terminal device successfully switches to the access network device, the core network element receives, from the target access network device, mapping relationship information between the terminal device and the target access network device, wherein the mapping relationship information comprises one or more of: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

54. The method of claim 53, wherein, The mapping relationship information comprises: In the case that no reselection of the core network element occurs in the session switching process, the mapping relationship information is received by all core network elements serving the terminal device from the target access network device; or In the case that reselection of the core network element occurs in the session switching process, the mapping relationship information is received by the reselected core network element from the target access network device; or The target core network element receives the mapping relationship information from the target access network device, wherein the target core network element is used to store context information and / or registration information of the terminal device and has a function of providing other network elements with query of the mapping relationship information.

55. The method of claim 54, wherein, The wireless access device further comprises the terminal device, and the session-related information further comprises: The core network element-related information sent by the reselected core network element to the terminal device, which is used for the terminal device to send and / or receive IP data packets with the core network element.

56. The method of claim 55, wherein, The core network element-related information comprises one or more of: The identity information of the terminal device; The address information of the terminal device; The address information of the access network device; The address information of the reselected core network element; The type information of the reselected core network element.

57. The method of claim 55 or 56, wherein, The core network element related information is carried in the payload of an IP data packet, and the address information of the terminal device and the address information of the access network device are carried in the header of the IP data packet.

58. The method of any one of claims 29-57, wherein, The session related information includes: In the case of reselection of the core network element, the reselection indication information sent by the source core network element or the target core network element to the terminal device, the reselection indication information being used to indicate the switching from the source core network element to the target core network element.

59. The method of claim 58, wherein, The switching indication information includes one or more of the following: The identity information of the terminal device; Information indicating that the core network element reselects; The address information of the target core network element; The type information of the target core network element.

60. The method of claim 58 or 59, wherein, The context information of the terminal device migrated from the source core network element to the target core network element includes one or more of the following: The identity information of the terminal device; The address information of the terminal device; The address information of the access network device.

61. A radio access equipment, characterized by It includes: A transceiver unit is configured to send an Internet Protocol (IP) data packet to a core network element and / or receive an IP data packet sent by the core network element, wherein the core network element is a session related element, and the IP data packet carries session related information.

62. The radio access device of claim 61, wherein, The wireless access device includes a terminal device, the core network element includes a session management element, and the session related information includes: A session request message sent by the terminal device to the session management element; and / or A session response message received by the terminal device from the session management element in response to the session request message, wherein the session response message includes a session accept message or a session reject message.

63. The wireless access device of claim 62, wherein: The session request message is a session establishment request message, and the session response message is a session establishment response message in response to the session establishment request message; or The session request message is a session modification request message, and the session response message is a session modification response message in response to the session modification request message; or The session request message is a session release request message, and the session response message is a session release response message in response to the session release request message. The session request message further includes one or more of the following:

64. The radio access equipment of claim 63, wherein, An identity of a session to be established; An identity of a session to be released; Single Network Slice Selection Assistance Information (S-NSSAI); Data Network Identifier (DNN); A type of session request message; Session and Service Continuity (SSC) mode; The address information of the terminal device; The identity information of the terminal device. The address information of the terminal device is carried in the header of the IP data packet as a source address of the IP data packet.

65. The radio access device of claim 64, wherein, The session accept message includes one or more of the following:

66. The radio access device of any one of claims 62 to 65, wherein, Session identity; Information indicating that the session request is accepted; Session type; SSC mode; S-NSSAI; ​ Quality of Service, QoS, rules; a session address of a session allocated to the terminal device.

67. The radio access device of any one of claims 62-66, wherein, The session reject message comprises one or more of: a session identity; information indicating rejection of the session request; a cause of rejection of the session request.

68. The radio access device of any of claims 62-66, wherein, The transceiver unit is further configured to: obtain session management network element related information from a Network Repository Function, NRF, the session management network element related information being used for the terminal device to send the session request message to the session management network element.

69. The radio access device of claim 68, wherein, The transceiver unit is specifically configured to: send a network element information request message to the NRF; and / or, receive a network element information response message sent by the NRF in response to the network element information request message, the network element information response message carrying the session management network element related information.

70. The radio access device of claim 69, wherein, The network element information request message comprises one or more of: identity information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; an S-NSSAI; a DNN; an access type of the session.

71. The radio access device of claim 69 or 70, wherein, The session management network element related information comprises one or more of: identity information of the terminal device; type information of the session management network element; address information of the session management network element; identity information of the session management network element.

72. The radio access device of any of claims 62-71, wherein, The session related information further comprises: a session authentication command message received by the terminal device from the session management network element, the session authentication command message carrying Extensible Authentication Protocol, EAP, request information sent by a Data Network-AAA; and / or, a session authentication complete message sent by the terminal device to the session management network element, the session authentication complete message carrying EAP response information; wherein the EAP request information and the EAP response information are used for secondary authentication of the terminal device.

73. The radio access device of claim 72, wherein, The session authentication command and / or the session authentication complete message further carries information of a data network specific identity.

74. The radio access device of any of claims 61-73, wherein, The wireless access device comprises an access network device, and the session related information comprises: core network tunnel information received by the access network device from the core network network element; and / or, access network tunnel information sent by the access network device to the core network network element; wherein the core network tunnel information and the access network tunnel information are used for establishing a user plane tunnel between the access network device and a user plane network element, the core network tunnel information comprising a Tunnel Endpoint Identifier, TEID, and address information of the user plane network element, and the access network tunnel information comprising a TEID and address information of the access network device.

75. The radio access device of claim 74, wherein, The core network network element further comprises the user plane network element, and the session related information comprises: the core network tunnel information received by the access network device from the user plane network element, and Session Management, SM, information received by the access network device from the session management network element other than the core network tunnel information; or, SM information received by the access network device from the session management network element, the SM information comprising the core network tunnel information.

76. The radio access device of claim 74, wherein The session related information comprises: The SM information sent by the access network device to the session management network element in addition to the access network tunnel information, and the access network tunnel information sent by the access network device to the user plane network element; or The SM information sent by the access network device to the session management network element, which includes the access network tunnel information.

77. The radio access device of claim 75 or 76, wherein, The session-related information further includes: The user plane network element-related information received by the access network device from the session management network element or the user plane network element, which is used for the access network device to send the access network tunnel information to the user plane network element.

78. The radio access device of claim 77, wherein, The user plane network element-related information includes one or more of the following: Type information of the user plane network element; Address information of the user plane network element; Identification information of the user plane network element.

79. The radio access device of any of claims 74 to 78, wherein, The access network device-related information is sent by the session management network element to the user plane network element, which is used for the user plane network element to send the core network tunnel information to the access network device.

80. The radio access device of claim 79, wherein, The access network-related information includes one or more of the following: Address information of the access network device; Identification information of the terminal device; Session identification.

81. The radio access device of any one of claims 61-80, wherein, The wireless access device includes a target access network device in a session switching process, and the session-related information includes: Mapping relationship information between the terminal device and the target access network device sent by the target access network device to the core network element after the session switching is performed and the terminal device is successfully switched to the access network device, wherein the mapping relationship information includes one or more of the following: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

82. The radio access network device of claim 81, wherein, The mapping relationship information includes: In the case where no reselection of the core network element occurs in the session switching process, the mapping relationship information sent by the access network device to all core network elements serving the terminal device; or In the case where reselection of the core network element occurs in the session switching process, the mapping relationship information sent by the access network device to the reselected core network element; or The mapping relationship information sent by the access network device to a target core network element, wherein the target core network element is used to store context information and / or registration information of the terminal device and has a function of providing other network elements with the function of querying the mapping relationship information.

83. The radio access network device of claim 82 wherein, The wireless access device further includes the terminal device, and the session-related information further includes: Core network element-related information received by the terminal device from the reselected core network element, which is used for the terminal device to send and / or receive IP data packets with the core network element.

84. The radio access device of claim 83, wherein, The core network element-related information includes one or more of the following: Identification information of the terminal device; Address information of the terminal device; Address information of the access network device; Address information of the reselected core network element; Type information of the reselected core network element.

85. The radio access device of claim 83 or 84, wherein, The core network element related information is carried in a payload of an IP data packet, and address information of the terminal device and address information of the access network device are carried in a packet header of the IP data packet.

86. The radio access device of any one of claims 71 to 85, wherein, The session related information includes: In a case where reselection of the core network element occurs, reselection indication information received by the terminal device from a source core network element or a target core network element, the reselection indication information being used to indicate switching from the source core network element to the target core network element.

87. The radio access equipment of claim 86, wherein, The switching indication information includes one or more of the following: identification information of the terminal device; information indicating that reselection of the core network element occurs; address information of the target core network element; type information of the target core network element.

88. The radio access device of claim 86 or 87, wherein, The context information of the terminal device migrated from the source core network element to the target core network element includes one or more of the following: identification information of the terminal device; address information of the terminal device; address information of an access network device.

89. A core network device, comprising: The core network device is a core network element, and includes: a transceiver, configured to receive an Internet Protocol (IP) data packet sent by a wireless access device and / or send an IP data packet to the wireless access device, wherein the core network element is a session related element, and session related information is carried in the IP data packet.

90. The core network device of claim 89, wherein, The wireless access device includes a terminal device, and the core network element includes a session management element, and the session related information includes: a session request message received by the session management element from the terminal device; and / or a session response message sent by the session management element to the terminal device and corresponding to the session request message, the session response message including a session accept message or a session reject message.

91. The core network device of claim 90, wherein the session request message is a session establishment request message, and the session response message is a session establishment response message corresponding to the session establishment request message; or the session request message is a session modification request message, and the session response message is a session modification response message corresponding to the session modification request message; or the session request message is a session release request message, and the session response message is a session release response message corresponding to the session release request message.

92. The core network device of claim 91, wherein, The session request message further includes one or more of the following: an identifier of a session to be established; an identifier of a session to be released; single network slice selection assistance information (S-NSSAI); a data network identifier (DNN); a type of the session request message; a session and service continuity (SSC) mode; address information of the terminal device; identification information of the terminal device.

93. The core network device of claim 92, characterized by The address information of the terminal device is carried in a packet header of the IP data packet as a source address of the IP data packet. 94.The core network device of any of claims 90-93, wherein, The session accept message includes one or more of the following: a session identifier; information indicating that the session request is accepted; a session type; an SSC mode; S-NSSAI; a quality of service (QoS) rule; a session address allocated to the session of the terminal device.

95. The core network device of any one of claims 90-94, wherein, The session reject message includes one or more of the following: a session identifier; information indicating rejection of the session request; a cause of rejection of the session request.

96. The core network device of any one of claims 90-95, wherein, The session request message is sent by the terminal device to the session management network element based on session management network element related information, and the session management network element related information is obtained from a network storage function (NRF).

97. The core network device of claim 96, wherein, The following information in the process in which the terminal device obtains the session management network element related information from the NRF is carried in an IP packet: a network element information request message sent by the terminal device to the NRF; and / or a network element information response message received by the terminal device from the NRF in response to the network element information request message, the network element information response message carrying the session management network element related information.

98. The core network device of claim 97, wherein, The network element information request message includes one or more of the following: identifier information of the terminal device; address information of the terminal device; type information of the session management network element; location information of the terminal device; an S-NSSAI; a DNN; an access type of a session.

99. The core network device of claim 97 or 98, wherein, The session management network element related information includes one or more of the following: identifier information of the terminal device; type information of the session management network element; address information of the session management network element; identifier information of the session management network element.

100. The core network device of any of claims 90-99, wherein, The core network device further includes a processing unit, The transceiver unit is further configured to obtain subscription data of the terminal device from a unified data management (UDM); The processing unit is configured to determine, based on the subscription data, whether to receive or reject the session request message.

101. The core network device of claim 100, wherein, If the DNN carried in the session request message is a local area data network (LADN), the processing unit is further configured to: obtain a service area of the LADN and determine whether the terminal device is located in the service area of the LADN; The service area of the LADN can be obtained based on one or more of the following: from an AMF; from a UDM; from a local configuration.

102. The core network device of any of claims 90-101, wherein, The session related information further includes: a session authentication command message sent by the session management network element to the terminal device, the session authentication command message carrying extensible authentication protocol (EAP) request information sent by a data network authentication, authorization and accounting (DN-AAA); and / or a session authentication completion message received by the session management network element from the terminal device, the session authentication completion message carrying EAP response information; The EAP request information and the EAP response information are used for secondary authentication of the terminal device.

103. The core network device of claim 102, characterized by The session authentication command and / or the session authentication completion message further carry information of a data network specific identity.

104. The core network device of claim 102 or 103, wherein, The transceiver unit is further configured to perform one or more of the following steps: The session management network element receives the EAP request information sent by the DN-AAA; The session management network element sends the EAP response information to the DN-AAA; The session management network element receives an authentication success message or an authentication failure message sent by the DN-AAA.

105. The core network device of any one of claims 89-104, wherein, The radio access device includes an access network device, and the session related information includes: core network tunnel information sent by the core network network element to the access network device; and / or, The access network tunnel information received by the core network element from the access network device; The core network tunnel information and the access network tunnel information are used to establish a user plane tunnel between the access network device and a user plane network element, the core network tunnel information comprises a tunnel endpoint identifier (TEID) and address information of the user plane network element, and the access network tunnel information comprises a TEID and address information of the access network device.

106. The core network device of claim 105, characterized by The core network element further comprises the user plane network element, and the session-related information comprises: The core network tunnel information sent by the user plane network element to the access network device, and session management (SM) information sent by the session management network element to the access network device, except for the core network tunnel information; or The SM information sent by the session management network element to the access network device, which comprises the core network tunnel information.

107. The core network device of claim 105 or 106, wherein, The session-related information comprises: The SM information received by the session management network element from the access network device, except for the access network tunnel information, and the access network tunnel information received by the user plane network element from the access network device; or The SM information received by the session management network element from the access network device, which comprises the access network tunnel information.

108. The core network device of claim 106 or 107, wherein, The session-related information further comprises: User plane network element-related information sent by the session management network element or the user plane network element to the access network device, the user plane network element-related information being used for the access network device to send the access network tunnel information to the user plane network element.

109. The core network device of claim 108, wherein, The user plane network element-related information comprises one or more of the following: Type information of the user plane network element; Address information of the user plane network element; Identification information of the user plane network element.

110. The core network device of any of claims 105-109, wherein, Access network device-related information sent by the session management network element to the user plane network element, the access network device-related information being used for the user plane network element to send the core network tunnel information to the access network device.

111. The core network device of claim 110, wherein, The access network-related information comprises one or more of the following: Address information of the access network device; Identification information of the terminal device; Session identification.

112. The core network device of any one of claims 90-111, wherein, The transceiver unit is further configured to: In a case where the session request is accepted, register with a unified data management (UDM), wherein information recorded by the UDM after the registration comprises address information of the terminal device and / or session address.

113. The core network device of any one of claims 89-112, wherein, The wireless access device comprises a target access network device in a session switching process, and the session-related information comprises: After performing session switching and successfully switching the terminal device to the access network device, the core network element receives, from the target access network device, mapping relationship information between the terminal device and the target access network device, wherein the mapping relationship information comprises one or more of the following: identification information of the terminal device; identification information of the access network device; address information of the terminal device; and address information of the access network device.

114. The core network device of claim 113, wherein, The mapping relationship information comprises: In a case where no reselection of the core network element occurs in the session switching process, all core network elements serving the terminal device receive the mapping relationship information from the target access network device; or, In a case where reselection of the core network element occurs in the session switching process, the reselected core network element receives the mapping relationship information from the target access network device; or, The target core network element receives the mapping relationship information from the target access network device, wherein the target core network element is configured to store context information and / or registration information of the terminal device and has a function of providing other network elements with a query of the mapping relationship information. The wireless access device further comprises the terminal device, and the session-related information further comprises:

115. The core network device of claim 114, characterized by The reselected core network element sends core network element-related information to the terminal device, and the core network element-related information is used for the terminal device to send and / or receive IP data packets with the core network element. The core network element-related information comprises one or more of the following:

116. The core network device of claim 115, wherein, Identity information of the terminal device; Address information of the terminal device; Address information of the access network device; Address information of the reselected core network element; Type information of the reselected core network element. The core network element-related information is carried in a payload of an IP data packet, and the IP data packet carries address information of the terminal device and address information of the access network device in a packet header.

117. The core network device of claim 115 or 116, wherein, The session-related information comprises:

118. The core network device of any one of claims 89-117, wherein, In a case where reselection of the core network element occurs, the source core network element or the target core network element sends reselection indication information to the terminal device, and the reselection indication information is used to indicate switching from the source core network element to the target core network element. The switching indication information comprises one or more of the following:

119. The core network device of claim 118, wherein, Identity information of the terminal device; Information indicating reselection of the core network element; Address information of the target core network element; Type information of the target core network element. The context information of the terminal device migrated from the source core network element to the target core network element comprises one or more of the following:

120. The core network device of claim 118 or 119, wherein, Identity information of the terminal device; Address information of the terminal device; Address information of the access network device. The wireless access device comprises a transceiver, a memory and a processor, the memory is configured to store a program, the processor is configured to invoke the program in the memory and control the transceiver to receive or send signals, so that the wireless access device performs the method according to any one of claims 1 to 28.

121. A radio access equipment, characterized by The core network device comprises a transceiver, a memory and a processor, the memory is configured to store a program, the processor is configured to invoke the program in the memory and control the transceiver to receive or send signals, so that the core network device performs the method according to any one of claims 29 to 60.

122. A core network device, comprising: The apparatus comprises a processor configured to invoke a program from a memory, so that the apparatus performs the method according to any one of claims 1 to 60.

123. An apparatus, comprising: ​ 124. A chip, comprising: including a processor to call a program from a memory, causing a device in which the chip is installed to perform the method according to any one of claims 1 to 60.

125. A computer readable storage medium, characterized in that, having a program stored thereon, the program causing a computer to perform the method according to any one of claims 1 to 60.

126. A computer program product, characterized in that, including a program that causes a computer to perform the method according to any one of claims 1 to 60.

127. A computer program, characterized in that, The computer program causes a computer to perform the method according to any one of claims 1 to 60.

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