Communication method and communication apparatus

Abstract

The present application relates to the technical field of communications. Provided are a communication method and a communication apparatus. The method is applied to a vehicle-mounted relay (VMR) device, and comprises: determining identification information of a first user plane function (UPF); and sending a first request message to a first network element, wherein the first request message is used for requesting the establishment of a first PDU session, the first PDU session being used for establishing an N3 connection between a VMR device and the first UPF, and the first network element serves the first PDU session. The method in the embodiments of the present application can realize N3 wireless backhaul between a VMR device and a first UPF.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on December 29, 2023, with application number 202311868357.7 and application name “Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a communication method and a communication device. Background Art

[0003] Currently, vehicle mounted relay (VMR) devices are proposed based on vehicle-mounted scenarios. VMR devices are usually deployed on moving vehicles and consist of access network devices and terminal devices. The terminal devices can be called VMR terminal devices, and the access network devices can be called VMR access network devices.

[0004] Because vehicles move, VMR access network equipment and VMR terminal devices also have mobility. The N3 interface between the typically stationary ground access network equipment and the core network's UPF can be implemented by deploying optical fiber on the ground. The N3 interface between the mobile VMR access network equipment and the core network's user plane function (UPF) can be carried over the protocol data unit (PDU) session between the VMR terminal device and the core network to achieve wireless backhaul of the N3 interface. This allows the VMR access network equipment to provide wireless access to other terminal devices near the vehicle.

[0005] However, how to establish an N3 connection between the VMR terminal device and the core network UPF through a PDU session remains to be solved. Summary of the Invention

[0006] The present application provides a communication method and a communication device, which can realize N3 wireless backhaul between a VMR device and a first UPF.

[0007] In a first aspect, a communication method is provided, which is applied to a vehicle-mounted relay VMR device, wherein the VMR device includes a first terminal device and an access network device, including:

[0008] Determine identification information of a first user plane function UPF;

[0009] A first request message is sent to the first network element, where the first request message is used to request the establishment of a first PDU session, where the first PDU session is used to establish an N3 connection between the VMR device and the first UPF, and the first network element serves the first PDU session.

[0010] In an embodiment of the present application, when the identification information of the first UPF is determined, a first request message for requesting to establish a first PDU session is sent to the first network element. In this way, an N3 connection between the VMR device and the first UPF can be established through the first PDU session, thereby enabling N3 wireless backhaul between the VMR device and the first UPF.

[0011] In some possible implementations, determining the first UPF includes: receiving a first message from a second network element, where the first message is used to indicate identification information of the first UPF.

[0012] In an embodiment of the present application, the VMR device can determine the identification information of the first UPF based on the first message from the second network element. In this way, the VMR device can be triggered to request to establish a first PDU session based on the identification information of the first UPF, thereby enabling N3 wireless backhaul between the VMR device and the first UPF.

[0013] In some possible implementations, before receiving the first message from the second network element, the method further includes: sending a second request message to the second network element, the second request message being used to request establishment of an N2 connection between the VMR device and the second network element, and the first message being a response message to the second request message.

[0014] In some possible implementations, the second request message also includes first indication information, and the first indication information is used to trigger the second network element to return the identification information of the first UPF.

[0015] In some possible implementations, the first indication information includes at least one of the following:

[0016] Location information of the VMR device;

[0017] The capability of the VMR device, wherein the capability is that the VMR device has the ability to establish an N3 connection with the UPF using a PDU session;

[0018] Identification information of the UPF requesting to establish an N3 connection through a PDU session.

[0019] In some possible implementations, the first request message further includes indication information for indicating that the first PDU session is used to establish N3 wireless backhaul.

[0020] In some possible implementations, the method further includes: receiving a second message from the first network element, where the second message is used to indicate that establishment of the first PDU session is complete.

[0021] In some possible implementations, the second message includes address information of the VMR device, and the address information of the VMR device is used to send uplink data of the second terminal device to the first UPF via N3 wireless backhaul, and the second terminal device is currently connected to the VMR device.

[0022] In some possible implementations, determining the first UPF includes: receiving a third message from a fourth network element, the third message being used to indicate identification information of the first UPF, the first UPF being the UPF associated with the second PDU session established for the second terminal device accessing the VMR device, the fourth network element serving the second PDU session, and the second terminal device currently accessing the VMR device.

[0023] In an embodiment of the present application, the VMR device can determine the identification information of the first UPF based on the third message from the fourth network element. In this way, the VMR device can be triggered to request to establish a first PDU session based on the identification information of the first UPF, thereby realizing N3 wireless backhaul between the VMR device and the first UPF.

[0024] In some possible implementations, the method further includes: saving a first correspondence between a second PDU session and the first PDU session, the second PDU session is established by the second terminal device through the VMR device, the second PDU session is associated with the first UPF, and the second terminal device is currently connected to the VMR device.

[0025] In some possible implementations, the method further includes: receiving uplink data from the second terminal device; and determining, based on the uplink data and the first correspondence, to transmit the uplink data through the N3 wireless backhaul corresponding to the first PDU session.

[0026] In some possible implementations, the method also includes: when the UPF associated with the second PDU session established by the second terminal device connected to the VMR device is updated from the first UPF to the second UPF, receiving a fourth message from a fourth network element, the fourth message being used to indicate the identification information of the second UPF, the fourth network element serving the second PDU session, and the second terminal device currently connected to the VMR device; determining, based on the identification information of the second UPF, that the N3 connection between the VMR device and the first UPF is updated to the N3 connection between the VMR device and the second UPF; and sending a third request message to the first network element, the third request message being used to request modification of the first PDU session so as to establish an N3 connection between the VMR device and the second UPF through the first PDU session.

[0027] In some possible implementations, the method further includes: receiving a fifth message from the second network element, the fifth message being used to request the release of the second PDU session; and in response to the fifth message, sending a fourth request message to the first network element, the fourth request message being used to request the release of the first PDU session.

[0028] In some possible implementations, the sending the fourth request message to the first network element includes: sending the fourth request message to the first network element when the N3 tunnel carried by the second PDU session is no longer used.

[0029] In some possible implementations, the method further includes: receiving a sixth message from the first network element, where the sixth message is used to indicate that the first PDU session has been released.

[0030] In a second aspect, a communication method is provided, applied to a first network element, including:

[0031] receiving a first request message from a vehicle-mounted relay VMR device, where the first request message is used to request establishment of a first protocol data unit (PDU) session, where the first PDU session is used to establish an N3 connection between a first user plane function (UPF) and the VMR device, where the VMR device includes a first terminal device and an access network device;

[0032] The first PDU session is established according to the first request message, and the first network element serves the first PDU session.

[0033] In an embodiment of the present application, the first request message is used to request the establishment of a first PDU session. The first network element receives the first request message from the VMR device and establishes the first PDU session based on the first request message. In this way, an N3 connection can be established between the VMR device and the first UPF through the first PDU session, thereby enabling N3 wireless backhaul between the VMR device and the first UPF.

[0034] In some possible implementations, the method further includes: sending a second message to the VMR device, where the second message is used to indicate that establishment of the first PDU session is complete.

[0035] In some possible implementations, the second message includes address information of the VMR device, and the address information of the VMR device is used to send uplink data of the second terminal device to the first UPF via N3 wireless backhaul, and the second terminal device is currently connected to the VMR device.

[0036] In some possible implementations, the method further includes: when the UPF associated with the second PDU session established by the second terminal device connected to the VMR device is updated from the first UPF to the second UPF, receiving a third request message from the VMR device, the third request message being used to request modification of the first PDU session so that the VMR device establishes an N3 connection between the VMR device and the second UPF through the first PDU session, and the second terminal device is currently connected to the VMR device; and modifying the first PDU session according to the third request message.

[0037] In some possible implementations, the method further includes: receiving a fourth request message from the VMR device, where the fourth request message is used to request the release of the first PDU session; and releasing the first PDU session in response to the fourth request message.

[0038] In some possible implementations, the method further includes: sending a sixth message to the VMR device, where the sixth message is used to indicate that the first PDU session has been released.

[0039] In a third aspect, a communication method is provided, applied to a second network element, including:

[0040] A first message is sent to a vehicle-mounted relay VMR device, where the first message is used to indicate identification information of a first user plane function UPF. The first UPF supports the VMR device to establish an N3 connection through a protocol data unit PDU session. The VMR device includes a first terminal device and an access network device.

[0041] In an embodiment of the present application, the first message is used to indicate the identification information of the first UPF. Sending the first message to the VMR device can enable the VMR device to determine the identification information of the first UPF. In this way, the VMR device can be triggered to request to establish a first PDU session based on the identification information of the first UPF, thereby realizing N3 wireless backhaul between the VMR device and the first UPF.

[0042] In some possible implementations, before sending the first message to the VMR device, the method further includes: receiving a second request message from the VMR device, the second request message being used to request establishment of an N2 connection between the VMR device and the second network element, and the first message being a response message to the second request message.

[0043] In some possible implementations, the second request message also includes first indication information, and the first indication information is used to trigger the second network element to return the identification information of the first UPF.

[0044] In some possible implementations, the first indication information includes at least one of the following:

[0045] Location information of the VMR device;

[0046] The capability of the VMR device, wherein the capability is that the VMR device has the ability to establish an N3 connection with the UPF;

[0047] Request the identification information of the UPF that establishes the N3 connection through the PDU session.

[0048] In some possible implementations, before sending the first message to the VMR device, the method also includes: sending a fifth request message to a third network element, wherein the fifth request message is used to request to query the identification information of the first UPF; and receiving a seventh message from the third network element, wherein the seventh message includes the identification information of the first UPF.

[0049] In some possible implementations, the fifth request message further includes location information of the VMR device.

[0050] In some possible implementations, the method further includes: saving a second correspondence between the identification information of the VMR device and the first UPF.

[0051] In some possible implementations, the method also includes: receiving a sixth request message from the VMR device, the sixth request message is used to request the establishment of a second PDU session, the second PDU session is established by the second terminal device through the VMR device, the second PDU session is associated with the first UPF, and the second terminal device is currently connected to the VMR device; determining the first UPF based on the sixth request message and the second correspondence; and sending the identification information of the first UPF to the fourth network element.

[0052] In a fourth aspect, a communication method is provided, which is applied to a third network element, including:

[0053] receiving a fifth request message from the second network element, where the fifth request message is used to request to query identification information of the first UPF;

[0054] Sending a seventh message to the second network element, where the seventh message includes identification information of the first UPF;

[0055] Among them, the first UPF supports the VMR device to establish an N3 connection with the first UPF through a protocol data unit PDU session, and the VMR device includes a first terminal device and an access network device.

[0056] In an embodiment of the present application, the seventh message includes the identification information of the first UPF. The third network element sends the seventh message to the second network element based on the fifth request message, which helps the second network element indicate the identification information of the first UPF to the VMR device, thereby helping to trigger the VMR device to request to establish a first PDU session based on the identification information of the first UPF, and further helping to realize the N3 wireless backhaul between the VMR device and the first UPF.

[0057] In some possible implementations, the fifth request message includes location information of the VMR device.

[0058] In some possible implementations, the method further includes: receiving capability indication information from a first user plane function UPF, where the capability indication information is used to indicate that the first UPF supports establishing an N3 connection with a VMR device through a PDU session.

[0059] In a fifth aspect, a communication device is provided, comprising: a module or unit for executing the method in any one of the above aspects or any possible implementation manner of any one of the aspects.

[0060] In a sixth aspect, a communication device is provided, comprising: a processor and a memory, wherein the processor is coupled to the memory, and the memory is used to store a computer program (also referred to as code or instruction). When the computer program is executed by the processor, the device executes the method in any one of the above aspects or any possible implementation of any one of the aspects.

[0061] In some possible implementations, the apparatus further includes a memory coupled to the processor.

[0062] In some possible implementations, there are one or more processors and / or one or more memories.

[0063] In some possible implementations, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0064] In the seventh aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions). When the computer program runs on a computer, the computer executes the method in any one of the above aspects or any possible implementation of any one of the aspects.

[0065] In an eighth aspect, a computer program product is provided, comprising: a computer program (also referred to as code, or instructions), which, when executed on a computer, enables the computer to execute a method in any one of the above aspects or any one of the possible implementations of any one of the aspects.

[0066] In the ninth aspect, a chip is provided, comprising: a processor and a memory, wherein the memory is used to store a computer program (also referred to as code, or instruction), and the processor is used to call and run the computer program stored in the memory, so that a device or equipment equipped with the chip executes the method in any one of the above aspects or any possible implementation of any one of the aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG1 is a schematic block diagram of a wireless communication system applicable to the present application.

[0068] FIG2 is a schematic block diagram of another wireless communication system applicable to the present application.

[0069] FIG3 is a schematic block diagram of a network architecture based on a VMR device in the present application.

[0070] FIG4 is a schematic flowchart of a communication method provided in one embodiment of the present application.

[0071] FIG5 is a schematic diagram of an application scenario in one embodiment of the present application.

[0072] FIG6 is a schematic flowchart of a communication method provided in one embodiment of the present application.

[0073] FIG7 is a schematic diagram of an application scenario in another embodiment of the present application.

[0074] FIG8 is a schematic flowchart of a communication method provided in another embodiment of the present application.

[0075] FIG9 is a schematic diagram of an application scenario in yet another embodiment of the present application.

[0076] FIG10 is a schematic flowchart of a communication method provided in yet another embodiment of the present application.

[0077] FIG11 is a schematic diagram of an application scenario in yet another embodiment of the present application.

[0078] FIG12 is a schematic flowchart of a communication method provided in yet another embodiment of the present application.

[0079] FIG13 is a schematic structural diagram of a communication device provided in one embodiment of the present application.

[0080] FIG14 is a schematic structural diagram of a communication device provided in another embodiment of the present application.

[0081] FIG15 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application.

[0082] FIG16 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application.

[0083] FIG17 is a schematic structural diagram of a device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0084] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0085] In the description of this application, unless otherwise specified, " / " indicates that the objects associated with each other are in an "or" relationship. For example, A / B can represent A or B. "And / or" in this application is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, in the description of this application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with basically the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and words such as "first" and "second" do not necessarily limit differences. It should be understood that in this application, similar expressions such as "under the circumstances of...", "if...", "when...", and "if..." can be used interchangeably.

[0086] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, etc. The technical solutions provided by the present application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0087] The terminal device in the embodiment of the present application may refer to user equipment (UE), station, access terminal, user unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile terminal (MT), user terminal, terminal, wireless communication device, user agent or user device, etc., and this is not limited in the embodiment of the present application. The terminal device in the embodiment of the present application may also be a mobile phone, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a large screen, a vehicle-mounted device, a wearable device, a terminal device in a 5G network or a terminal device in a future evolved public land mobile communication network (PLMN), etc., and this is not limited in the embodiment of the present application. The terminal device in the embodiments of the present application may also be a tablet computer (Pad), a laptop computer, a PDA, 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 a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc., and this is not limited in the embodiments of the present application.

[0088] In some embodiments, the terminal device can be configured to act as a base station. Optionally, the terminal device can act as a dispatching entity, providing sidelink signals between terminal devices in vehicle-to-everything (V2X) or device-to-device (D2D) communications. For example, a cell phone and a car can communicate using sidelink signals, or a cell phone and a smart home device can communicate using sidelink signals without relaying the communication signals through a base station.

[0089] The network device in the embodiment of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network, and may also be referred to as a base station. For example, the network device may be a NodeB, an evolved NodeB (eNodeB), a next generation NodeB (gNB) in a 5G mobile communication system, a transmission reception point (TRP), an access point (AP), a base station in a future mobile communication system or an access point (AP) in a WiFi system, a wireless controller in a cloud radio access network (CRAN) scenario, a relay station, an access point, a vehicle-mounted device, a wearable device, a network device in other communication systems that will evolve in the future, and the like.

[0090] In some embodiments, multiple RAN nodes may collaborate to assist terminal devices in achieving wireless access, and different RAN nodes may respectively implement part of the functions of a base station. For example, a RAN node (i.e., a network device in this application) may be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and DU may be set separately, or may be included in the same network element, such as a baseband unit (BBU). The RU may be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art may understand their meanings. For example, in an open radio access network (ORAN) system, CU may also be referred to as an open CU (O-CU), DU may also be referred to as an open DU (O-DU), CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. Any unit of the CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. It should be understood that this application does not limit the specific technology and specific device form adopted by the network device.

[0091] In some embodiments, the network device may be fixed or mobile, which is not limited in the embodiments of the present application. For example, a helicopter or drone may be configured as a mobile network device, and one or more cells may be moved based on the location of the mobile network device. In other examples, a helicopter or drone may be configured to communicate with another network device.

[0092] In some embodiments, network devices may be deployed on land or in the air, which is not limited in the embodiments of the present application. For example, network devices may be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites.

[0093] In an embodiment of the present application, a terminal device or a network device may include a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system may be any one or more computer operating systems that implement business processing through processes, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Furthermore, in the embodiment of the present application, the specific structure of the execution subject of the method provided in the embodiment of the present application is not particularly limited, as long as it is possible to communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application.

[0094] In addition, various aspects or features of the present application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used in this application covers computer programs that can be accessed from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memories (EPROMs), cards, sticks, or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0095] Figure 1 is an exemplary architecture diagram of a wireless communication system used in an embodiment of the present application. The wireless communication system 100 is a 5G network architecture based on a service-oriented architecture. The wireless communication system 100 may include a terminal device, a data network (DN), and an operator portion.

[0096] The operator part may include one or more of the following network elements:

[0097] Network slice selection function (NSSF), authentication server function (AUSF) network element, network exposure function (NEF) network element, policy control function (PCF) network element, unified data management (UDM) network element, unified data repository (UDR), network repository function (NRF) network element, application function (AF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, network slice specific authentication and authorization function (NSSAAF) network element, service communication proxy (SCP) network element, network slice admission control function (NSACF) network element, radio access network (RAN) and user plane function (UPF) network element, etc. In the above operator network, the part other than the wireless access network can be called the core network part.

[0098] The AF network element is similar to an application server, interacting with other core network control plane network elements and providing business services. AF network elements can exist for different application services and can be owned by operators or trusted third parties.

[0099] PCF network elements support a unified policy framework to manage network behavior and provide policy rules to network entities for implementation.

[0100] The UDM network element is responsible for the management of user identification, contract data, authentication data, and user service network element registration management.

[0101] The UPF network element is a data processing module in the core network. Its main function is to route and forward data from the base station to the network.

[0102] The AMF network element is responsible for UE identity verification, authorization, registration, mobility management, and connection management functions.

[0103] The SMF network element is mainly responsible for allocating addresses to terminals and managing various channels between terminals and the core network.

[0104] It is understood that Figure 1 exemplarily shows an architecture diagram of a communication system applicable to the method provided in the embodiment of the present application. The communication system applicable to the method provided in the embodiment of the present application may include other network elements or network entities, which are not limited in the embodiment of the present application.

[0105] Figure 2 is another exemplary architecture diagram of a wireless communication system used in an embodiment of the present application. Wireless communication system 200 is a 5G network architecture based on a point-to-point interface. The primary difference between wireless communication system 200 and wireless communication system 100 is that the interfaces between network elements in wireless communication system 200 are point-to-point interfaces, rather than service-based interfaces.

[0106] With the advancement of communication technology, 3GPP communication systems have introduced mobile relay scenarios to provide wireless access to terminal devices in the vicinity of the mobile relay. For example, the 3GPP SA2 working group proposed the mobile base station relay (MBSR) for vehicle-mounted scenarios. MBSR is also known as vehicle-mounted relay (VMR).

[0107] VMR devices can be deployed on mobile vehicles and may include access network equipment (which may be called VMR-gNB) and terminal equipment (which may be called VMR-UE). VMR-UE may have the functions of a UE (which may refer to a common UE different from a VMR-UE), for example, it may be connected to the core network through NR access.

[0108] Among them, the VMR device can also be called a wireless access and backhauling (WAB) device, the terminal device in the WAB device can be called a WAB-UE, and the access network device in the WAB device can be called a WAB-base station.

[0109] Typically, the N3 interface between a fixed gNB on the ground and the core network UPF can be implemented by deploying optical fiber on the ground. However, the N3 interface between the mobile VMR-gNB and the core network cannot be implemented using optical fiber. If the N3 interface between the VMR-gNB and the core network is carried over the protocol data unit (PDU) session between the VMR-UE and the core network, wireless backhauling of the N3 interface can be implemented through the PDU session. In this way, the VMR-gNB can provide wireless access to other UEs near the VMR device. The wireless backhaul of the N3 interface can also be referred to as N3 wireless backhaul. The N3 interface between the VMR-gNB and the core network UPF is used to establish the N3 connection between the VMR-gNB and the core network UPF. Therefore, the N3 interface can also be referred to as the N3 connection.

[0110] The following description takes the case where the access network device in the VMR device is a VMR-gNB and the terminal device in the VMR device is a VMR-UE as an example.

[0111] As shown in Figure 3, the UE can access the VMR device (or access the VMR-gNB). The VMR-UE in the VMR device can access the core network through the base station on the ground (also called the donor-gNB) and establish a PDU session with the VMR-UPF. The VMR-UPF can refer to the anchor UPF for the VMR-UE to establish the PDU session (or the anchor UPF for the PDU session established by the VMR-UE). The PDU session established between the VMR-UPF and the VMR-UE can be used to establish an N3 connection between the VMR device and the N3 UPF. The N3 UPF can refer to the UPF that has an N3 connection with the VMR-gNB (or the UPF in the core network accessed by the UE). The N3 message transmission between the VMR-gNB and the N3 UPF can be implemented through the PDU session between the VMR-UE and the VMR-UPF. For example, when the VMR-gNB needs to send a PDU message to the N3 UPF, the N3 message can be transmitted between the VMR-gNB and the N3 UPF. When the UPF sends the N3 message, the VMR-gNB can forward the N3 message to the VMR-UE through the internal interface between the VMR-UE and the VMR-UE. The VMR-UE can pass the N3 message as a data packet payload to the anchor UPF (i.e., VMR-UPF) of the PDU session through the PDU session between the VMR-UE and the anchor UPF. The anchor UPF then forwards the data packet payload (or load) to the N3 UPF, thereby completing the forwarding of the uplink N3 message.

[0112] From the above description, it can be seen that the VMR-UE can establish a PDU session with the VMR-UPF. The PDU session can be used to carry the N3 message between the VMR-gNB and the N3 UPF, thereby realizing N3 wireless backhaul.

[0113] However, it is not clear how to determine with which N3 UPF the VMR device establishes an N3 connection through the PDU session between the VMR-UE and the VMR-UPF; at the same time, after determining the N3 UPF, it is not clear how to trigger the VMR device to establish a PDU session for realizing the N3 connection with the N3 UPF (that is, the PDU session between the VMR-UE and the VMR-UPF, which can be used to establish the N3 connection between the VMR device and the N3 UPF).

[0114] In order to solve one or more of the above technical problems, the present application proposes a communication method and a communication device. The communication method in the embodiment of the present application is described in detail with reference to FIG4 .

[0115] FIG4 is a schematic flow chart of a communication method provided by an embodiment of the present application. The method 400 shown in FIG4 may include steps S410 and S420, which are specifically as follows:

[0116] S410: The VMR device determines identification information of the first UPF.

[0117] The VMR device may include a first terminal device (such as VMR-UE) and an access network device (such as VMR-gNB).

[0118] The second terminal device can currently access the VMR device through the NR technology, and the second terminal device can be a common UE. For example, the second terminal device is a UE that accesses the network through the VMR device.

[0119] The first UPF is the N3 UPF mentioned above. In some embodiments, the first UPF may refer to a UPF in the core network accessed by the second terminal device, or the UPF serving the second terminal device, or the UPF associated with the second PDU session established with the second terminal device accessing the VMR device. Optionally, the first UPF may support the VMR device in establishing an N3 connection with the first UPF via a PDU session.

[0120] The identification information of the first UPF may be address information of the first UPF, for example, the Internet protocol (IP) address of the first UPF.

[0121] In some embodiments, the identification information of the first UPF may be obtained through the second network element. For example, in S410, the second network element may send a first message to the VMR device.

[0122] The second network element may be a mobility management network element serving the second terminal device, for example, an AMF.

[0123] Among them, the first message can be used to indicate the identification information of the first UPF. For example, the first message can be the N2 response message sent by the AMF to the VMR device in step S607 of Figure 6, or the session establishment request message sent by the AMF to the VMR device in step S810 of Figure 8.

[0124] In some embodiments, before the second network element sends the first message to the VMR device, the method 400 may include step S402, which is as follows:

[0125] S402: The VMR device sends a second request message to the second network element.

[0126] The VMR device sending the second request message to the second network element means that the access network device (e.g., VMR-gNB) in the VMR device sends the second request message to the second network element. The second request message can be used to request the establishment of an N2 connection between the VMR device and the second network element. For example, the second request message can be the N2 request message sent by the VMR-gNB to the AMF in step S603 of Figure 6. In other words, the first message sent by the second network element to the VMR device in step S410 can be a response message to the second request message.

[0127] The second request message may include identification information of the VMR device. Specifically, the identification information of the VMR device includes identification information of the VMR-gNB and, optionally, identification information of the VMR-UE. It can be understood that in step S402, the identification information of the VMR-gNB may include the following:

[0128] Case 1: The identification information of the VMR device may include both the identification information of the VMR-gNB and the identification information of the VMR-UE.

[0129] Case 2: The VMR device identification information only includes the VMR-gNB identification information;

[0130] The identification information of the VMR-gNB may be a VMR-gNB ID. The identification information of the VMR-UE may be a subscription permanent identifier (SUPI) or a general public subscription identifier (GPSI) of the VMR-UE, which is not limited in this application.

[0131] Optionally, the second request message may further include first indication information, and the first indication information may be used to trigger the second network element to return identification information of the first UPF.

[0132] Optionally, the first indication information may include at least one of the following:

[0133] Location information of the VMR device;

[0134] The capability of the VMR device, which may be the ability of the VMR device to establish an N3 connection with the UPF;

[0135] Identification information of the UPF requesting to establish an N3 connection through a PDU session.

[0136] In some embodiments, after the VMR device sends the second request message to the second network element, the method 400 may include step S404, which is as follows:

[0137] S404: The second network element may send a fifth request message to the third network element.

[0138] Among them, the fifth request message can be used to request to query the identification information of the first UPF. For example, the fifth request message can be the query request message sent by the AMF to the NRF in step S604 of Figure 6.

[0139] Optionally, the third network element may be a network storage network element, for example, an NRF.

[0140] Optionally, the fifth request message may further include location information of the VMR device.

[0141] In some embodiments, after the second network element may send the fifth request message to the third network element, the method 400 may include step S406, which is specifically as follows:

[0142] S406: The third network element may send a seventh message to the second network element.

[0143] Among them, the seventh message may include the identification information of the first UPF. For example, the seventh message may be the query response message sent by the NRF to the AMF in step S605 of Figure 6.

[0144] In an embodiment of the present application, the third network element sends the seventh message to the second network element, which helps the second network element indicate the identification information of the first UPF to the VMR device, thereby helping to trigger the VMR device to request to establish a first PDU session based on the identification information of the first UPF, and further helping to realize the N3 wireless backhaul between the VMR device and the first UPF.

[0145] In some embodiments, before receiving the fifth request message sent by the second network element, method 400 may include step S405, which is specifically as follows:

[0146] S405, the third network element can also receive the network element registration request message sent by the first UPF.

[0147] Among them, the network element registration request message can be used to request the first UPF to be registered in the network. For example, the network element registration request message can be the network element registration request message sent by the UPF to the NRF in step S601 of Figure 6.

[0148] Optionally, the network element registration request message may include identification information and capability indication information of the first UPF, and the capability indication information may be used to indicate that the first UPF can establish an N3 connection with the VMR device through a PDU session (or that the first UPF can establish an N3 wireless backhaul with the VMR device through a PDU session).

[0149] In some embodiments, after receiving the seventh message, method 400 may include step S408, specifically as follows:

[0150] S408: The second network element may save a second correspondence between the identification information of the VMR device and the identification information of the first UPF.

[0151] The identification information of the VMR device may be the identification information sent by the VMR device to the second network element in the above step S402.

[0152] According to the above description, since the identification information of the VMR device exists in different situations, the second correspondence between the identification information of the VMR device and the identification information of the first UPF that can be stored by the second network element also exists in the following different situations:

[0153] Case 1: The second correspondence includes the correspondence between the identification information of the VMR-gNB, the identification information of the VMR-UE, and the identification information of the first UPF;

[0154] Case 2: The second correspondence includes the correspondence between the identification information of the VMR-gNB and the identification information of the first UPF;

[0155] The identification information of the VMR-gNB may be a VMR-gNB ID. The identification information of the VMR-UE may be the Subscription Permanent Identifier (SUPI) or the Generic Public Subscription Identifier (GPSI) of the VMR-UE, which is not limited in this application.

[0156] In some embodiments, the identification information of the first UPF may also be obtained through the fourth network element. For example, in S410, the fourth network element may send a third message to the VMR device, and the third message may be used to indicate the identification information of the first UPF.

[0157] The fourth network element may serve the second PDU session, or in other words, the fourth network element may serve the second terminal device. The second PDU session may be a PDU session established by the second terminal device connected to the VMR device. Optionally, the fourth network element may be a session management network element, such as an SMF.

[0158] S420: The VMR device sends a first request message to the first network element.

[0159] The first request message may be used to request establishment of a first PDU session, which may be used to establish an N3 connection between the VMR device and the first UPF. For example, the first request message may be the session establishment request message sent by the VMR device to the VMR-SMF in step S608 of FIG. 6 , or the session establishment request message sent by the VMR device to the VMR-SMF in step S812 of FIG. 8 .

[0160] Specifically, the VMR device sending the first request message to the first network element may refer to: the terminal device in the VMR device (ie, VMR-UE) sending the first request message to the first network element. The first request message also includes identification information of the first PDU session.

[0161] Optionally, the first network element may serve the first PDU session, or in other words, the first network element may serve the VMR device. Optionally, the first network element may be a session management network element, such as an SMF.

[0162] The first request message may further include indication information for indicating that the first PDU session is used to establish N3 wireless backhaul.

[0163] In an embodiment of the present application, after determining the identification information of the first UPF, the VMR device sends a first request message to the first network element for requesting to establish a first PDU session. In this way, an N3 connection can be established between the VMR device and the first UPF through the first PDU session, thereby enabling N3 wireless backhaul between the VMR device and the first UPF.

[0164] In some embodiments, after receiving the first request message, method 400 may include step S421, specifically as follows:

[0165] S421: The first network element may select a third UPF for the first PDU session. The third UPF is the anchor UPF of the first PDU session (ie, the VMR-UPF in FIG3 ), or in other words, the third UPF may serve the first PDU session of the VMR device.

[0166] Optionally, the first network element may further allocate address information to the VMR device. Optionally, the address information is the IP address of a terminal device (VMR-UE) in the VMR device.

[0167] In some embodiments, after receiving the first request message, method 400 may include step S422, specifically as follows:

[0168] S422: The first network element may send a second message to the VMR device.

[0169] The second message may be used to indicate that the establishment of the first PDU session is complete, and the second message may be a response message to the first request message. For example, the second message may be the session establishment response message sent by the VMR-SMF to the VMR device in step S610 of FIG. 6 , or the session establishment response message sent by the VMR-SMF to the VMR device in step S814 of FIG. The first network element may send the second message to the VMR device, which may mean that the first network element may send the second message to the terminal device (i.e., VMR-UE) in the VMR device.

[0170] Optionally, the second message may include address information of the VMR device (such as address information allocated by the first network element to the VMR-UE). Optionally, the address information of the VMR-UE may be used to send uplink data of the second terminal device to the first UPF via N3 wireless backhaul.

[0171] Optionally, after receiving the address information, the VMR device (ie, VMR-UE) may use the address information as the source IP address of an uplink N3 general packet radio service (GPRS) user plane part (GTP, GTP-U) tunnel.

[0172] In some embodiments, method 400 may include step S423, specifically as follows:

[0173] S423: The VMR device may send a sixth request message to the second network element.

[0174] The sixth request message may be used to request establishment of a second PDU session. For example, the sixth request message may be the session establishment request message sent by the VMR device to the AMF in step S613 of Figure 6 . Specifically, the session establishment request message is sent by the second terminal device to the second network element via the VMR device. Furthermore, in this step, the VMR also sends VMR device identification information to the second network element. Specifically, the VMR device identification information includes VMR-gNB identification information and, optionally, VMR-UE identification information.

[0175] After receiving the sixth request message, the second network element may select a fourth network element for the second terminal device, and the fourth network element may serve the second PDU session of the second terminal.

[0176] Optionally, after the VMR device sends the sixth request message to the second network element, the method 400 may include step S424, which is as follows:

[0177] S424, the second network element may determine the first UPF according to the sixth request message and the second corresponding relationship.

[0178] The second corresponding relationship may refer to the corresponding relationship between the identification information of the VMR device stored locally by the second network element in the above step S408 and the identification information of the first UPF.

[0179] Specifically, the second network element may determine the identifier of the first UPF corresponding to the identifier of the VMR device according to the identifier information of the VMR device received in step S423 and the second corresponding relationship locally stored by the second network element in step S408.

[0180] Optionally, after the second network element determines the first UPF according to the sixth request message and the second corresponding relationship, the method 400 may include step S425, which is specifically as follows:

[0181] S425: The second network element may send identification information of the first UPF to the fourth network element, wherein the identification information of the first UPF may be used to trigger the fourth network element to establish a second PDU session.

[0182] Optionally, after establishing the second PDU session, the fourth network element may send a session establishment accept message to the second network element.

[0183] Optionally, after receiving the session establishment accept message, the second network element may send a session establishment request message to the VMR device. The session establishment request message may be a response message to the sixth request message sent by the VMR device to the second network element in step S423. The session establishment request message may be used to trigger the VMR device to establish a context for a PDU session. For example, the session establishment request message may be the session establishment request message sent by the AMF to the VMR device in step S617 of FIG. 6 .

[0184] The process of the fourth network element establishing the second PDU session can refer to the existing technology. In this process, the fourth network element can send the identification information of the second PDU session and the N3 tunnel information of the second PDU session to the VMR device. The N3 tunnel information of the second PDU session includes the identification information of the first UPF.

[0185] In some embodiments, method 400 may include step S426, specifically as follows:

[0186] S426: The VMR device saves the first correspondence between the second PDU session and the first PDU session.

[0187] The second PDU session is established by the second terminal device through the VMR device and is associated with the first UPF.

[0188] The meaning of the VMR device storing the first correspondence between the second PDU session and the first PDU session may mean: the VMR device storing the correspondence between the identification information of the second PDU session and the identification information of the first PDU session, or the VMR device storing the correspondence between the N3 tunnel information of the second PDU session and the identification information of the first PDU session. Alternatively, the VMR device storing the correspondence between the identification information of the first UPF associated with the second PDU session and the identification information of the first PDU session.

[0189] In some embodiments, method 400 may include step S427, specifically as follows:

[0190] S427: The VMR device may receive uplink data from the second terminal device.

[0191] Optionally, the method 400 may include step S428, which is as follows:

[0192] S428 , the VMR device determines, based on the uplink data and the first correspondence, to transmit the uplink data through the N3 wireless backhaul corresponding to the first PDU session.

[0193] The specific method for the VMR device to determine the transmission of uplink data through the N3 wireless backhaul corresponding to the first PDU session based on the uplink data and the first correspondence is: after receiving the uplink data, the VMR device can determine the data radio bearer (DRB) carrying the uplink data, and determine that the PDU session corresponding to the DRB is the second PDU session. At this time, according to the first correspondence, it can be determined that the second PDU session corresponds to the first PDU session, and the VMR device can use the N3 wireless backhaul corresponding to the first PDU session to transmit the uplink data.

[0194] At this time, the VMR device may transmit the uplink data to the third UPF. Optionally, after receiving the uplink data, the third UPF may send the uplink data to the first UPF.

[0195] In this application, there may be a situation where the UPF associated with the second PDU session changes due to the movement of the second terminal device. In this case, the VMR device can initiate a session modification process.

[0196] In some embodiments, method 400 may include step S430, specifically as follows:

[0197] S430, when the UPF associated with the second PDU session established by the second terminal device connected to the VMR device is updated from the first UPF to the second UPF, the fourth network element may send a fourth message to the VMR device.

[0198] The fourth message may be used to indicate identification information of the second UPF. For example, the fourth message may be a session modification request message sent by the SMF to the VMR device in step S1001 of FIG. 10 .

[0199] Optionally, after the fourth network element sends the fourth message to the VMR device, the method 400 may include step S432, which is specifically as follows:

[0200] S432, the VMR device can determine that the N3 connection between the VMR device and the first UPF needs to be updated based on the identification information of the second UPF. For example, the N3 connection between the VMR device and the first UPF needs to be updated to an N3 connection between the VMR device and the second UPF.

[0201] Optionally, after determining that the N3 connection between the VMR device and the first UPF needs to be updated, the method 400 may include step S434, which is as follows:

[0202] At step S434, the VMR device may send a third request message to the first network element. The third request message may be used to request modification of the first PDU session so as to establish an N3 connection between the VMR device and the second UPF via the first PDU session. For example, the third request message may be the session modification request message sent by the VMR device to the VMR-SMF in step S1003 of FIG. 10 .

[0203] In some embodiments, after the VMR device sends the third request message to the first network element, the method 400 may include step S436, which is specifically as follows:

[0204] S436: The first network element may modify the first PDU session according to the third request message. For example, the first network element may modify the first PDU session to establish an N3 connection between the VMR device and the second UPF.

[0205] In the present application, if after the second PDU session of the second terminal device is released, if the N3 tunnel carried by the second PDU session is no longer used, the VMR device can trigger the release process of the first PDU session.

[0206] In some embodiments, the method 400 may include step S440, specifically as follows:

[0207] S440: The second network element may send a fifth message to the VMR device.

[0208] Among them, the fifth message can be used to request the release of the second PDU session. For example, the fifth message can be the resource release request message sent by the AMF to the VMR device in step S1206 of Figure 12.

[0209] Optionally, the method 400 may include step S442, which is specifically as follows:

[0210] S442: In response to the fifth message, the VMR device may send a fourth request message to the first network element.

[0211] The fourth request message may be used to request the release of the first PDU session. For example, the fourth request message may be the session release request message sent by the VMR device to the VMR-SMF in step S1209 of FIG. 12 .

[0212] Optionally, the VMR device may determine whether the N3 tunnel carried by the second PDU session still needs to be used, for example, whether the N3 tunnel is associated with other sessions.

[0213] Optionally, when the N3 tunnel carried by the second PDU session is no longer used, the VMR device may send a fourth request message to the first network element.

[0214] In some embodiments, after receiving the fourth request message, method 400 may include step S444, specifically as follows:

[0215] S444: The first network element may release the first PDU session according to the fourth request message.

[0216] Optionally, in response to the fourth request message, the first network element may release the first PDU session.

[0217] In some embodiments, after the first network element releases the first PDU session, the method 400 may include step S446, specifically as follows:

[0218] S446: The first network element may send a sixth message to the VMR device.

[0219] The sixth message may be used to indicate that the first PDU session has been released. For example, the sixth message may be a session release command sent by the VMR-SMF to the VMR device in step S1211 of FIG. 12 .

[0220] Figure 5 is a schematic diagram of an application scenario in one embodiment of the present application. In Figure 5, UE1 and UE2 access a VMR device and are connected to a core network through the VMR device.

[0221] As shown in Figure 5, the UPF that establishes N3 wireless backhaul with the VMR device is fixed, that is, the UPF that the VMR device accesses through N3 wireless backhaul (the UPF has an N3 interface with the VMR device), then, as long as the UE accesses the VMR device, the UPF associated with the UE's PDU session is the UPF that the VMR device accesses through N3 wireless backhaul (that is, the UPF associated with the UE's PDU session is the UPF that establishes N3 wireless backhaul with the VMR device through PDU session), that is, in Figure 5, the UPF associated with UE1's PDU session and the UPF associated with UE2's PDU session are both UPFs that the VMR device accesses through N3 wireless backhaul, that is, the UPF associated with UE1's PDU session and the UPF associated with UE2's PDU session and the UPF that the VMR device establishes N3 wireless backhaul through PDU session are the same UPF.

[0222] The following describes the communication method in the embodiment of the present application by way of example based on the application scenario shown in FIG5 in conjunction with FIG6 .

[0223] Figure 6 is a schematic flow chart of a communication method provided by an embodiment of the present application. In the method shown in Figure 6, the VMR device may include a VMR-gNB and a VMR-UE, the VMR-SMF is the first network element in the method shown in Figure 4, the AMF is the second network element in the method shown in Figure 4, the NRF is the third network element in the method shown in Figure 4, and the SMF is the fourth network element in the method shown in Figure 4.

[0224] The method 600 shown in FIG6 may include steps S601 to S618, which are specifically as follows:

[0225] S601, UPF sends a network element registration request message to NRF.

[0226] The registration request message may be an NF registration request message, such as a service-based operation Nnrf_NFManagement_NFRegister message.

[0227] The network element registration request message can be used to register the UPF with the network. The network element registration request message may carry the identification information of the UPF, the service area of ​​the UPF, and the capability indication information. The identification information may be address information. The service area of ​​the UPF may be a list of tracking areas (TAs) that the UPF can serve. Optionally, the capability indication information may be used to indicate that the UPF supports access via N3 wireless backhaul, or in other words, the capability indication information is used to indicate that the UPF supports the VMR device to establish an N3 connection (or N3 interface) with the UPF through a PDU session.

[0228] It should be noted that the UPF in step S601 is a general term and does not refer to a specific UPF.

[0229] S602a, the VMR-UE registers with the core network.

[0230] The VMR-UE can register with the core network through a gNB (e.g., a donor gNB). The registration process can refer to the existing technology.

[0231] S602b: The VMR-UE establishes a PDU session.

[0232] The VMR-UE can establish a PDU session for the VMR-gNB to access the AMF. This PDU session can be used to establish N2 wireless backhaul. This PDU session is used to access the AMF that has an N2 connection with the VMR-gNB (i.e., an N2 interface exists between the VMR-gNB and the AMF). Therefore, when the VMR-gNB needs to send an uplink N2 message to the AMF, the VMR-gNB can send the uplink N2 message to the AMF via the UPF, the anchor point for this PDU session. When the AMF needs to send a downlink N2 message to the VMR-gNB, the AMF can send the downlink N2 message to the VMR-gNB via the UPF, the anchor point for this PDU session.

[0233] S603: The VMR-gNB sends an N2 request message to the AMF.

[0234] The N2 request message may be an NG setup request message.

[0235] The VMR-gNB may send an NG setup request message to the AMF via the N2 wireless backhaul. The NG setup request message may carry the VMR-gNB ID and indication information, which may be used to trigger the AMF to return the identification information of the first UPF.

[0236] The identification information of the first UPF may be the address information of the first UPF. The first UPF is a UPF that enables the VMR-gNB to establish an N3 wireless backhaul between the VMR-gNB and the first UPF through a PDU session, such as the UPF in S601. This can also be understood as the first UPF supporting the VMR-gNB in ​​establishing an N3 connection with the first UPF through a PDU session, or supporting the VMR-gNB in ​​accessing the first UPF through the user plane of the PDU session.

[0237] Optionally, the indication information may be used to indicate at least one of the following:

[0238] 1) Current location information of the VMR device;

[0239] 2) VMR-UE capabilities, for example, the UE has the ability to establish an N3 connection with the UPF using PDU sessions;

[0240] 3) Identification information of the UPF requesting to establish an N3 connection through a PDU session.

[0241] S604: AMF sends a query request message to NRF.

[0242] Among them, the AMF can send a query request message to the NRF based on the indication information included in step S603.

[0243] The query request message may be a network element discovery request message, which may be used to request the identification information of the first UPF. For example, the AMF may send a network element discovery request message to the NRF. The network element discovery request message may be a service-based operation Nnrf_NFDiscovery_Request message.

[0244] Optionally, the query request message may carry a network element type, which is used to indicate that the network element requested to be queried by the query request message is a UPF that supports establishing N3 wireless backhaul through a PDU session.

[0245] Optionally, the query request message may also carry the location information of the VMR device. The location information may be represented by a tracking area identity (TAI). Optionally, the location information of the VMR device may be used to instruct the NRF to return a UPF whose service area includes the location of the VMR device.

[0246] Optionally, the query request message may also carry capability indication information of the UPF requested to be discovered, where the capability indication information is used to indicate that the UPF requested to be discovered supports the capability of establishing an N3 connection through a PDU session.

[0247] S605: NRF sends a query response message to AMF.

[0248] The query response message may be a discovery response message, and the discovery response message may carry identification information of the first UPF. Specifically, the NRF returns the identification information of the first UPF according to the query request message.

[0249] Optionally, if the query request message carries the location information of the VMR device, the service area of ​​the first UPF returned by the NRF includes the location of the VMR device.

[0250] For example, the NRF may return a network element discovery response message to the AMF.

[0251] S606. The AMF saves the correspondence between the identification information of the VMR-gNB and the first UPF.

[0252] For example, the AMF can save the correspondence between the ID of the VMR-gNB and the identification information of the first UPF (that is, the VMR-gNB can establish N3 wireless backhaul with the first UPF through a PDU session).

[0253] S607: AMF sends an N2 response message to the VMR-gNB.

[0254] The N2 response message may be an NG setup response message.

[0255] Optionally, the N2 response message can be used to indicate identification information of the first UPF.

[0256] S608a: The VMR device establishes a PDU session.

[0257] Upon receiving the identification information of the first UPF, the VMR device may initiate a session establishment process, where the PDU session is used to access the first UPF.

[0258] For example, the VMR-gNB can trigger the VMR-UE to initiate a session establishment process based on the identification information of the first UPF carried in the N2 response message. For convenience of description, the PDU session established by the VMR device for implementing N3 wireless backhaul with the first UPF can be referred to as the first PDU session, or the PDU session established by the VMR device for accessing the first UPF via N3 wireless backhaul can be referred to as the first PDU session.

[0259] S608b: The VMR device sends a session establishment request message to the core network.

[0260] The VMR-UE may send a session establishment request message to the VMR-SMF. The session establishment request message may be used to establish a PDU session between the VMR-UE and the core network (eg, VMR-UPF).

[0261] Optionally, the session establishment request message may further carry indication information, wherein the indication information may be used to indicate that the PDU session (ie, the PDU session between the VMR-UE and the core network) is used to establish the N3 wireless backhaul.

[0262] Optionally, the session establishment request message may also carry identification information of the first UPF, and the identification information of the first UPF is used to assist the core network in establishing the first PDU session.

[0263] In addition, if the PDU session used to establish the N2 wireless backhaul between the VMR-gNB and the AMF is different from the PDU session used to establish the N3 wireless backhaul between the VMR-gNB and the UPF, then in step S608b, the VMR device sends a session establishment request message to the core network. Therefore, the steps described in Figure 6 are mainly described for this scenario.

[0264] If the PDU session used to establish the N2 wireless backhaul between the VMR-gNB and the AMF is the same PDU session used to establish the N3 wireless backhaul between the VMR-gNB and the UPF, then in step S608b, the VMR device sends a session modification request message to the core network. Optionally, the session modification request message may also carry indication information, where the indication information may be used to indicate that the PDU session modification request (i.e., the PDU session between the VMR-UE and the core network) is used to establish the N3 wireless backhaul.

[0265] Optionally, the session modification request message may also carry identification information of the first UPF, and the identification information of the first UPF is used to assist the core network in modifying the first PDU session.

[0266] S609: The VMR-SMF selects a UPF for the session.

[0267] The VMR-SMF can select a suitable UPF (i.e., VMR-UPF) for the session and establish an N4 session. At the same time, the VMR-SMF can also allocate an IP address to the VMR-UE.

[0268] If, in step S608b, the session establishment request message carries the identification information of the first UPF, the VMR-SMF can select an appropriate UPF (i.e., the VMR-UPF) based on the identification information of the first UPF, thereby ensuring that the deployment location of the VMR-UPF is close to the deployment location of the first UPF, thereby shortening the latency required for the VMR-UPF to access the first UPF. The VMR-UPF is the anchor UPF for the session, and the VMR device can access the first UPF through the VMR-UPF, thereby implementing N3 wireless backhaul between the VMR device and the first UPF.

[0269] S610: The VMR-SMF sends a session establishment response message to the VMR device.

[0270] The session establishment response message may be an Nsmf_PDU Session_Create SM Context Response message, and the session establishment response message may be used to indicate that the establishment of the PDU session between the VMR-UE and the core network is complete.

[0271] For example, the VMR-SMF may send an Nsmf_PDU Session_Create SM Context Response message to the VMR device.

[0272] Optionally, the session establishment response message may also carry the IP address of the VMR-UE.

[0273] In step S611, the VMR-gNB uses the IP address of the VMR-UE as the source address of the uplink N3 general packet radio service (GPRS) user plane part (GTP, GTP-U) tunnel.

[0274] After obtaining the IP address of the VMR-UE, the VMR-gNB can use the IP address of the VMR-UE as the source IP address of the uplink N3GTP-U tunnel.

[0275] S612: The UE sends a session establishment request message to the VMR device.

[0276] The UE can access through the VMR device and initiate a session establishment process through the VMR device. For the convenience of description, the PDU session that the UE requests to establish through the VMR device is called a second PDU session.

[0277] S613: The VMR device sends a session establishment request message to the AMF.

[0278] The VMR device can send the session establishment request message sent by the UE to the AMF.

[0279] S614, AMF determines the UPF according to the stored correspondence.

[0280] The AMF can determine the identifier of the first UPF (that is, the VMR device can establish N3 wireless backhaul with the first UPF through a PDU session) based on the stored corresponding relationship (such as the corresponding relationship saved in step S606).

[0281] For example, the AMF can determine based on the stored correspondence: if the identification information of the UPF that can establish N3 wireless backhaul with the VMR device is present, then the UPF is the first UPF.

[0282] S615, AMF sends the identification information of the first UPF to SMF.

[0283] AMF sends the identification information of the first UPF to SMF to trigger SMF to establish an N4 session.

[0284] Specifically, the SMF uses the first UPF as the UPF for the second PDU session of the UE and sends the N4 session establishment process to the first UPF.

[0285] S616, SMF sends a session establishment accept message to AMF.

[0286] S617: AMF sends a session request message to the VMR device.

[0287] The session establishment request message may be an N2 PDU session request message, and the session request message may be used to trigger the VMR device to establish the context of the session.

[0288] For example, the AMF may send an N2 PDU session establishment request message to the VMR device.

[0289] S618: The VMR device sends a session establishment response message to the UE.

[0290] The session establishment response message may be a response message to the session establishment request message sent by the UE in step S612, and may be used to indicate that the session establishment is complete.

[0291] After the session is established, the UE can send uplink data through the VMR device (i.e., VMR-gNB); after receiving the uplink data, the VMR device (i.e., VMR-gNB) can perform N3 GTP-U encapsulation on the UE's uplink data based on the context information of the UE's second PDU session, where the source IP address of the N3 GTP-U encapsulation is the address of the VMR-gNB, and the destination address is the address of the first UPF. After the UE's uplink data is N3 GTP-U encapsulated, the VMR-gNB sends the encapsulated data to the VMR-UE, and the VMR-UE sends the data to the anchor UPF of the first PDU session through the first PDU session. After the anchor UPF of the first PDU session receives the uplink data from the VMR-UE, the anchor UPF of the first PDU session determines that the destination address of the uplink data is the address of the first UPF, and further forwards the data to the first UPF.

[0292] Figure 7 is a schematic diagram of an application scenario in one embodiment of the present application. In Figure 7, UE1, UE2, and UE3 access a VMR device and are connected to a core network through the VMR device.

[0293] As shown in Figure 7, the VMR device can establish multiple UPFs for N3 wireless backhaul through PDU sessions. When different UEs access the VMR device and establish PDU sessions with different UPFs, it is necessary to determine which UPF the VMR device should establish N3 wireless backhaul with. For example, the UPF associated with UE1's PDU session and the UPF associated with UE2's PDU session are both UPF1, and the UPF associated with UE3's PDU session is UP2. In this case, the VMR device needs to establish N3 wireless backhaul with UPF1 through PDU session 1, and establish N3 wireless backhaul with UPF2 through PDU session 2.

[0294] The following describes the communication method in the embodiment of the present application by way of example based on the application scenario shown in FIG7 in conjunction with FIG8 .

[0295] Figure 8 is a schematic flow chart of a communication method provided by one embodiment of the present application. In the method shown in Figure 8, the VMR device may include a VMR-gNB and a VMR-UE. The VMR-SMF is the first network element in the method shown in Figure 4, the AMF is the second network element in the method shown in Figure 4, and the SMF is the fourth network element in the method shown in Figure 4.

[0296] The method 800 shown in FIG8 may include steps S801 to S823, which are specifically as follows:

[0297] First, the VMR-UE can register with the core network through the registration process. At the same time, the VMR-UE can establish a PDU session for accessing the AMF to complete the establishment of the N2 wireless backhaul (that is, the VMR device can establish the N2 wireless backhaul between the AMF and the VMR device through the PDU session).

[0298] S801: UE sends a registration request message to a VMR device.

[0299] S802: The VMR device sends a registration request message to the AMF.

[0300] S803, AMF sends a registration acceptance message to the VMR device.

[0301] S804: The VMR device sends a registration acceptance message to the UE.

[0302] S805: The UE sends a session establishment request message to the VMR device.

[0303] The UE may send a session establishment request message to the AMF through the VMR device. The AMF may refer to the AMF serving the UE.

[0304] For the convenience of description, the PDU session that the UE requests to establish through the VMR device is called the second PDU session.

[0305] S806: The VMR device sends a session establishment request message to the AMF.

[0306] The VMR device can send a session establishment request message to the AMF.

[0307] S807, AMF sends a session establishment request message to SMF.

[0308] The SMF may refer to the SMF serving the UE.

[0309] For example, the AMF may select the SMF for the session of the UE and send a session establishment request message to the SMF to trigger the SMF to establish the session.

[0310] S808, SMF establishes N4 session.

[0311] The SMF can select the UPF for the UE's session and trigger the N4 session establishment process.

[0312] S809, SMF sends a session establishment response message to AMF.

[0313] The session establishment response message may be a Namf_Communication_N1N2MessageTransfer message.

[0314] For example, SMF can send a Namf_Communication_N1N2MessageTransfer message to AMF.

[0315] The Namf_Communication_N1N2MessageTransfer message may include N2 SM information, which may include a PDU session identifier (ID) and core network tunnel information (CN tunnel information).

[0316] Optionally, the N2 SM information may include UPF identification information, where the UPF may be the UPF selected by the SMF for the UE session, or the UPF serving the UE. Optionally, the identification information may be address information.

[0317] S810, AMF sends a session request message to the VMR device.

[0318] The session request message may be an N2 PDU Session Request message. Optionally, the session request message may be used to indicate identification information of a UPF (such as the UPF selected by the SMF for the UE's session in S809).

[0319] For example, the AMF sends an N2 PDU Session Request message to the VMR device.

[0320] Optionally, the session establishment request message may include N2 SM information. The N2 SM information may carry the PDU session ID and core network tunnel information (such as CN Tunnel Info), and the core network tunnel information may include N3 tunnel information of the second PDU session.

[0321] S811: The VMR device establishes a PDU session.

[0322] Upon receiving the UPF identification information indicated by the AMF, the VMR device can initiate the session establishment process.

[0323] For example, the VMR-gNB can trigger the VMR-UE to establish a PDU session for N3 wireless backhaul based on the UPF identification information contained in the session request message (as received in S810).

[0324] For the sake of convenience of description, the PDU session established by the VMR device to implement N3 wireless backhaul with the first UPF is called the first PDU session, or it can be understood that the PDU session established by the VMR device to access the first UPF through N3 wireless backhaul is called the first PDU session.

[0325] S812: The VMR device sends a session establishment request message to the core network.

[0326] The session establishment request message may be used to request establishment of a PDU session between the VMR-UE and the core network (eg, VMR-UPF).

[0327] For example, the VMR-UE may send a session establishment request message to the VMR-SMF.

[0328] Optionally, the session establishment request message may include identification information of the first UPF (eg, the UPF selected by the SMF for the UE's session in S809). The first PDU session is used to establish an N3 wireless backhaul between the first UPF and the VMR device.

[0329] S813, VMR-SMF selects UPF for the session.

[0330] If the session establishment request message in step S812 carries the identification information of the UPF, the VMR-SMF can select an appropriate UPF (i.e., VMR-UPF) for the PDU session between the VMR-UE and the core network based on the identification information of the UPF, thereby ensuring that the deployment location of the VMR-UPF is close to the location of the UPF carried in the session establishment request message, thereby shortening the delay required for the VMR-UPF to access the UPF. The VMR-UPF is the anchor UPF for the first PDU session.

[0331] S814, the VMR-SMF sends a session establishment response message to the VMR device.

[0332] The session establishment response message may be used to indicate that the PDU session between the VMR-UE and the core network is established. The session establishment response message may carry the IP address of the VMR-UE.

[0333] S815: The VMR device saves the correspondence between the second PDU session of the UE and the first PDU session currently established by the VMR device.

[0334] Among them, the first PDU session currently established by the VMR device may refer to the PDU session between the VMR-UE and the VMR-UPF, and the second PDU session of the UE may refer to the PDU session between the UE and the UPF (the UPF may refer to the UPF serving the UE) established through the VMR-gNB.

[0335] Optionally, the meaning of the VMR device saving the correspondence between the second PDU session and the first PDU session may mean: the VMR device saves the correspondence between the identification information of the second PDU session and the identification information of the first PDU session, or the VMR device saves the correspondence between the N3 tunnel information of the second PDU session and the identification information of the first PDU session, or the VMR device saves the correspondence between the identification information of the first UPF associated with the second PDU session and the identification information of the first PDU session.

[0336] Among them, the N3 tunnel information of the second PDU session can be carried in the session request message sent by the AMF to the VMR device in the above step S810.

[0337] S816: The VMR device sends a session establishment response message to the UE.

[0338] The VMR device may send a session establishment response message to the UE. The session establishment response message may be used to indicate to the UE that the establishment of the second PDU session between the VMR-UE and the core network is complete.

[0339] S817, the VMR device sends a session establishment response message to the AMF.

[0340] Among them, the session establishment response message can be an N2 PDU Session Response message, which can be used to indicate to the AMF that the PDU session between the VMR-UE and the core network is established.

[0341] For example, the VMR device can send an N2 PDU Session Response message to the AMF.

[0342] Optionally, the session establishment response message may include N2 SM information, and the N2 SM information may carry tunnel information (such as AN Tunnel Info).

[0343] S818, AMF sends a session update request message to SMF.

[0344] The session update request message may be an Nsmf_PDUSession_UpdateSMContext Request message.

[0345] For example, AMF may send a Nsmf_PDUSession_UpdateSMContext Request message to SMF.

[0346] S819, SMF updates N4 session.

[0347] SMF can trigger N4 session update.

[0348] S820. UE sends uplink data.

[0349] The UE can send uplink data through the VMR device.

[0350] S821: The VMR device performs N3 GTP-U encapsulation on the uplink data.

[0351] Specifically, after receiving the uplink data sent by the UE, the VMR device can determine the data radio bearer (DRB) carrying the uplink data, and determine that the PDU session corresponding to the DRB is the second PDU session. At this time, according to the correspondence, it can be determined that the second PDU session corresponds to the first PDU session, that is, the uplink data is transmitted through the first PDU session. At this time, the VMR device (that is, VMR-gNB) can perform N3 GTP-U encapsulation on the uplink data of the UE according to the context information of the second PDU session of the UE, where the source IP address of the N3 GTP-U encapsulation is the address of the VMR-gNB, and the destination address is the address of the UPF (that is, the first UPF) accessed by the first PDU session.

[0352] S822: The VMR device sends uplink data to the VMR-UPF.

[0353] Specifically, after the UE's uplink data is encapsulated by N3 GTP-U, the VMR-gNB sends the encapsulated data to the VMR-UE, and the VMR-UE sends the data to the anchor point UPF of the first PDU session (i.e., VMR-UPF) through the first PDU session.

[0354] S823a, the VMR-UPF addresses the corresponding UPF according to the address of the first UPF.

[0355] Specifically, after the VMR-UPF receives uplink data from the VMR-UE, the VMR-UPF determines that the destination address of the uplink data is the address of the first UPF.

[0356] S823b, VMR-UPF sends the uplink data to the corresponding UPF.

[0357] Figure 9 is a schematic diagram of an application scenario in one embodiment of the present application. In Figure 9, the second terminal device may move, causing the UPF (such as N3 UPF) to which it is connected to change. In this case, the VMR device can initiate a session modification process.

[0358] As shown in FIG9 , UE1 needs to update the connected N3 UPF from UPF1 to UPF2 due to mobility. After receiving the identification information (such as address information) of UPF2, the VMR device can initiate a session modification process.

[0359] Below, in conjunction with Figure 10, the communication method in the embodiment of the present application is illustrated based on the application scenario shown in Figure 9.

[0360] Figure 10 is a schematic flow chart of a communication method provided by one embodiment of the present application. In the method shown in Figure 10, the VMR device may include a VMR-gNB and a VMR-UE, the VMR-SMF is the first network element in the method shown in Figure 4, the AMF is the second network element in the method shown in Figure 4, and the SMF is the fourth network element in the method shown in Figure 4.

[0361] The method 1000 shown in FIG10 may include steps S1001 to S1009, which are specifically as follows:

[0362] As the VMR-gNB moves, the UPF corresponding to the second PDU session established by the UE will change (such as UPF relocation), for example, from the previous UPF to the new UPF. If the VMR device establishes an N3 connection with the previous UPF through the first PDU session, then after the UPF changes, the VMR device needs to modify the user plane path of the first PDU session to establish an N3 connection with the new UPF through the first PDU session.

[0363] S1001, SMF sends a session modification request message to the VMR device (i.e., VMR-gNB).

[0364] The session modification request message may be an N2 PDU Session modification request message, and the session modification request message may be used to indicate identification information of a new N3 UPF.

[0365] For example, the SMF may send an N2 PDU Session modification request message to the VMR device. The modification request message may carry N2 SM information, and the N2 SM information may include new core network tunnel information (CN tunnel information).

[0366] Optionally, the N2 SM information may include identification information (such as address information) of a new UPF. The new UPF may be the second UPF in the above method 400.

[0367] S1002: The VMR device modifies the first PDU session.

[0368] After receiving the identification information of the new N3 UPF, the VMR device can determine that the N3 connection between the VMR device and the first UPF needs to be updated, for example, determine that the N3 connection between the VMR device and the first UPF needs to be updated to the N3 connection between the VMR device and the second UPF.

[0369] At this time, the VMR device may trigger a session modification process to modify the PDU session modification process for the N3 wireless backhaul.

[0370] S1003: The VMR device sends a session modification request message to the VMR-SMF.

[0371] Among them, the session modification request message can be a PDU session modification request message, which can be used to request modification of the first PDU session between the VMR device and the VMR-UPF so as to realize the N3 connection between the VMR device and the second UPF through the PDU session.

[0372] For example, the VMR device may send a PDU session modification request message to the VMR-SMF.

[0373] Optionally, the session modification request message may carry identification information of the PDU session (such as a session ID).

[0374] Optionally, the session modification request message may also carry identification information of the second UPF.

[0375] S1004: VMR-SMF modifies the current session.

[0376] The VMR-SMF can modify the current PDU session based on the identification information of the second UPF. For example, an uplink classifier (ULCL) / branching point (BP) can be inserted to ensure that the N3 wireless backhaul between the VMR device and the second UPF can be established through the PDU session, and the N3 delay between the VMR device and the second UPF is the shortest.

[0377] S1005: The VMR-SMF sends a session modification command to the VMR device.

[0378] Optionally, the session modification command may also carry address information allocated to the VMR-UE.

[0379] S1006: The VMR device sends a session modification command to the UE.

[0380] The session modification command is used to modify the second PDU session established by the UE through the VMR device.

[0381] S1007: The VMR device sends a session modification response message to the AMF.

[0382] The session modification response message may be an N2 PDU Session Response message.

[0383] For example, the VMR device can send an N2 PDU Session Response message to the AMF.

[0384] Optionally, the session modification response message may carry N2 SM information, and the N2 SM information may carry tunnel information (such as AN Tunnel Info).

[0385] S1008, AMF sends a session update request message to SMF.

[0386] The session update request message may be an Nsmf_PDUSession_UpdateSMContextRequest message.

[0387] For example, AMF may send a Nsmf_PDUSession_UpdateSMContext Request message to SMF.

[0388] S1009, SMF updates N4 session.

[0389] SMF can trigger N4 session update.

[0390] Figure 11 is a schematic diagram of an application scenario in one embodiment of the present application. In Figure 11, if the PDU session of a UE (such as UE1 and / or UE2) is released, and the N3 tunnel carried by the VMR-UE PDU session is no longer used, the VMR device can trigger the release process of the PDU session used for N3 wireless backhaul (i.e., the first PDU session).

[0391] As shown in FIG11 , after the PDU session of UE1 and the PDU session of UE2 are released, the N3 tunnel carried by the VMR-UE PDU session is no longer used, and the VMR device can trigger the release process of the PDU session used for N3 wireless backhaul.

[0392] Below, in conjunction with Figure 12, the communication method in the embodiment of the present application is illustrated based on the application scenario shown in Figure 11.

[0393] Figure 12 is a schematic flow chart of a communication method provided by one embodiment of the present application. In the method shown in Figure 12, the VMR device may include a VMR-gNB and a VMR-UE, the VMR-SMF is the first network element in the method shown in Figure 4, the AMF is the second network element in the method shown in Figure 4, and the SMF is the fourth network element in the method shown in Figure 4.

[0394] The method 1200 shown in FIG12 may include steps S1201 to S1211, which are specifically as follows:

[0395] S1201: The UE sends a session release request message through the VMR device.

[0396] The session release request message may be a UE RequestedPDU SessionRelease message, and the session release request message may be used to request the release of a PDU session between the UE and the core network.

[0397] For example, the UE may send a UE Requested PDU Session Release message to the VMR device.

[0398] S1202: The VMR device sends a session release request message to the AMF.

[0399] For example, the VMR device can send a UE Requested PDU Session Release message to the AMF.

[0400] S1203, AMF sends a session release request message to SMF.

[0401] The session release request message may be an Nsmf_PDUSession_ReleaseSMContext Request message, and the session release request message may be used to request the release of the PDU session between the UE and the core network.

[0402] For example, the AMF may send a Nsmf_PDUSession_ReleaseSMContext Request message to the SMF.

[0403] S1204, SMF releases N4 session.

[0404] SMF can trigger the release of N4 session.

[0405] S1205, SMF sends a session release response message to AMF.

[0406] The session release response message may be an Nsmf_PDUSession_ReleaseSMContext Response message, which may be used to indicate that the release of the PDU session between the UE and the core network is complete.

[0407] For example, the SMF may send a Nsmf_PDUSession_ReleaseSMContext Response message to the AMF.

[0408] S1206: AMF sends a resource release request message to the VMR device.

[0409] The resource release request message may be an N2 SM Resource Release request message, and the resource release request message may request to release the PDU session between the UE and the core network.

[0410] For example, the AMF may send an N2 SM Resource Release request message to the VMR device.

[0411] S1207: The VMR device sends a session release command to the UE.

[0412] The session release command may be a PDU Session Release Command.

[0413] For example, the VMR device may send a PDU Session Release Command to the UE.

[0414] S1208: The VMR device triggers a session release process.

[0415] The VMR device can determine: if after the PDU session between the UE and the core network is released, the N3 tunnel carried by the PDU session between the VMR-UE and the core network is no longer used (such as no other UE has any session associated with the N3 tunnel), then the VMR device can trigger the release process to release the PDU session between the VMR-UE and the core network.

[0416] S1209: The VMR device sends a session release request message to the VMR-SMF.

[0417] The session release request message may be a UE Requested PDU Session Release message, and the session release request message may be used to request the release of the PDU session between the VMR-UE and the core network.

[0418] For example, the VMR device may send a UE Requested PDU Session Release message to the VMR-SMF.

[0419] S1210, VMR-SMF releases session N4.

[0420] VMR-SMF can trigger the release of the N4 session.

[0421] S1211, the VMR-SMF sends a session release command to the VMR device.

[0422] The session release command may be a PDU Session Release Command.

[0423] VMR-SMF can send a PDU Session Release Command to the VMR device.

[0424] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 12. The device embodiment of the present application is described in detail below in conjunction with Figures 13 to 17. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0425] Figure 13 is a schematic structural diagram of a communication device provided in an embodiment of the present application. The device 1300 can be used to execute the actions or steps executed by the above-mentioned VMR device.

[0426] As shown in FIG13 , the apparatus 1300 includes a determining unit 1310 and a sending unit 1320 , specifically as follows:

[0427] The determining unit 1310 is configured to determine identification information of a first user plane function UPF;

[0428] The sending unit 1320 is used to send a first request message to the first network element, where the first request message is used to request the establishment of a first PDU session, where the first PDU session is used to establish an N3 connection between the VMR device and the first UPF, and the first network element serves the first PDU session.

[0429] Figure 14 is a schematic structural diagram of a communication device provided in another embodiment of the present application. The device 1400 can be used to execute the actions or steps executed by the first network element.

[0430] As shown in FIG14 , the apparatus 1400 includes a receiving unit 1410 and an establishing unit 1420 , specifically as follows:

[0431] A receiving unit 1410 is configured to receive a first request message from a vehicle-mounted relay VMR device, where the first request message is used to request establishment of a first protocol data unit (PDU) session, where the first PDU session is used to establish an N3 connection between a first user plane function (UPF) and the VMR device, where the VMR device includes a first terminal device and an access network device.

[0432] The establishing unit 1420 is configured to establish the first PDU session according to the first request message, and the first network element serves the first PDU session.

[0433] Figure 15 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application. The device 1500 can be used to execute the actions or steps executed by the second network element.

[0434] As shown in FIG15 , the apparatus 1500 includes a sending unit 1510 , which is specifically as follows:

[0435] The sending unit 1510 is used to send a first message to the vehicle relay VMR device, where the first message is used to indicate the identification information of the first user plane function UPF. The first UPF supports the VMR device to establish an N3 connection through a PDU session. The VMR device includes a first terminal device and an access network device.

[0436] Figure 16 is a schematic structural diagram of a communication device provided in yet another embodiment of the present application. The device 1600 can be used to execute the actions or steps executed by the third network element.

[0437] As shown in FIG16 , the apparatus 1600 includes a receiving unit 1610 and a sending unit 1620 , specifically as follows:

[0438] The receiving unit 1610 is configured to receive a fifth request message from the second network element, where the fifth request message is used to request to query identification information of the first UPF;

[0439] The sending unit 1620 is configured to send a seventh message to the second network element, where the seventh message includes identification information of the first UPF;

[0440] Among them, the first UPF supports the VMR device to establish an N3 connection with the first UPF through a protocol data unit PDU session, and the VMR device includes a first terminal device and an access network device.

[0441] FIG17 is a schematic diagram of the structure of an apparatus provided in one embodiment of the present application. The dashed lines in FIG17 indicate that the unit or module is optional. Apparatus 1700 may be used to implement the method described in the above method embodiment. Apparatus 1700 may be a chip or a communication device.

[0442] The device 1700 may include one or more processors 1710. The processor 1710 may support the device 1700 to implement the method described in the method embodiment above. The processor 1710 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0443] The apparatus 1700 may further include one or more memories 1720. The memories 1720 store programs that can be executed by the processor 1710, causing the processor 1710 to perform the methods described in the above method embodiments. The memories 1720 may be independent of the processor 1710 or integrated into the processor 1710.

[0444] The apparatus 1700 may further include a transceiver 1730. The processor 1710 may communicate with other devices or chips via the transceiver 1730. For example, the processor 1710 may transmit and receive data with other devices or chips via the transceiver 1730.

[0445] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0446] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0447] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a computer, the computer implements the steps in the above-mentioned various method embodiments.

[0448] An embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device (such as a server or a terminal device), the electronic device implements the steps in the above-mentioned various method embodiments.

[0449] An embodiment of the present application provides a chip, which includes a processor and a memory, wherein the memory is used to store computer programs, and the processor is used to call and run the computer programs stored in the memory, so that an electronic device (such as a server or terminal device) equipped with the chip executes the steps in the above-mentioned method embodiments.

[0450] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may at least include: any entity or device that can carry the computer program code to the device / electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electric carrier signal, a telecommunication signal and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, a computer-readable storage medium cannot be an electric carrier signal or a telecommunication signal.

[0451] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0452] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0453] In the embodiments provided in the present application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0454] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0455] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A communication method, applied to a vehicle-mounted relay VMR device, the VMR device comprising a first terminal device and an access network device, characterized in that, Including: Determine the identification information of the first User Plane Function (UPF); Send a first request message to a first network element, where the first request message is used to request the establishment of a first PDU session, and the first PDU session is used to establish an N3 connection between the VMR device and the first UPF, and the first network element serves the first PDU session.

2. The method according to claim 1, wherein The determining of the first UPF includes: Receive a first message from a second network element, where the first message is used to indicate the identification information of the first UPF.

3. The method according to claim 2, characterized in that, Before receiving the first message from the second network element, the method further includes: Send a second request message to the second network element, where the second request message is used to request the establishment of an N2 connection between the VMR device and the second network element, and the first message is a response message to the second request message.

4. The method according to claim 3, wherein The second request message further includes first indication information, where the first indication information is used to trigger the second network element to return the identification information of the first UPF.

5. The method according to claim 4, wherein The first indication information includes at least one of the following: The location information of the VMR device; The capability of the VMR device, where the capability is the capability of the VMR device to establish an N3 connection with a UPF using a PDU session; The identification information of the UPF that requests to establish an N3 connection through a PDU session.

6. The method according to claim 1, wherein The first request message further includes indication information for indicating that the first PDU session is used to establish an N3 radio backhaul.

7. The method according to any one of claims 1 to 6, characterized in that, The method further includes: Receive a second message from the first network element, where the second message is used to indicate the completion of the establishment of the first PDU session.

8. The method according to claim 7, characterized in that The second message includes the address information of the VMR device, and the address information of the VMR device is used to send the uplink data of a second terminal device to the first UPF through the N3 radio backhaul, and the second terminal device is currently connected to the VMR device.

9. The method according to claim 1, characterized in that, The determining of the first UPF includes: Receive a third message from a fourth network element, where the third message is used to indicate the identification information of the first UPF, and the first UPF is the UPF associated with a second PDU session established for a second terminal device accessing the VMR device, the fourth network element serves the second PDU session, and the second terminal device is currently connected to the VMR device.

10. The method according to any one of claims 1 to 9, characterized in that The method further includes: Save a first correspondence between the second PDU session and the first PDU session, where the second PDU session is established by a second terminal device through the VMR device, the second PDU session is associated with the first UPF, and the second terminal device is currently connected to the VMR device.

11. The method according to claim 10, wherein The method further includes: Receive the uplink data from the second terminal device; Determine to transmit the uplink data through the N3 radio backhaul corresponding to the first PDU session according to the uplink data and the first correspondence.

12. The method according to any one of claims 1 to 11, characterized in that, The method further includes: When the UPF associated with the second PDU session established by the second terminal device accessing the VMR device is updated from the first UPF to the second UPF, receive a fourth message from a fourth network element, where the fourth message is used to indicate the identification information of the second UPF, the fourth network element serves the second PDU session, and the second terminal device is currently accessing the VMR device; Determine, according to the identification information of the second UPF, that the N3 connection between the VMR device and the first UPF is updated to the N3 connection between the VMR device and the second UPF; Send a third request message to the first network element, where the third request message is used to request modification of the first PDU session so as to establish, through the first PDU session, the N3 connection between the VMR device and the second UPF.

13. The method according to any one of claims 1 to 12, characterized in that, The method further includes: Receive a fifth message from a second network element, where the fifth message is used to request release of the second PDU session; In response to the fifth message, send a fourth request message to the first network element, where the fourth request message is used to request release of the first PDU session.

14. A communication method, applied to a first network element, characterized in that, Includes: Receive a first request message from a vehicle-mounted relay VMR device, where the first request message is used to request establishment of a first protocol data unit (PDU) session, and the first PDU session is used to establish an N3 connection between a first user plane function (UPF) and the VMR device, and the VMR device includes a first terminal device and an access network device; Establish the first PDU session according to the first request message, and the first network element serves the first PDU session.

15. The method according to claim 14, characterized in that, The method further includes: Send a second message to the VMR device, where the second message is used to indicate that the establishment of the first PDU session is completed.

16. The method according to claim 15, wherein The second message includes the address information of the VMR device, and the address information of the VMR device is used to send the uplink data of the second terminal device to the first UPF through N3 wireless backhaul, and the second terminal device is currently accessing the VMR device.

17. The method according to any one of claims 14 to 16, characterized in that, The method further includes: When the UPF associated with the second PDU session established by the second terminal device accessing the VMR device is updated from the first UPF to the second UPF, receive a third request message from the VMR device, where the third request message is used to request modification of the first PDU session so that the VMR device can establish, through the first PDU session, the N3 connection between the VMR device and the second UPF, and the second terminal device is currently accessing the VMR device; Modify the first PDU session according to the third request message.

18. A communication method, applied to a second network element, characterized in that Includes: Send a first message to a vehicle-mounted relay VMR device, where the first message is used to indicate the identification information of a first user plane function (UPF), and the first UPF supports the VMR device to establish an N3 connection with the first UPF through a protocol data unit (PDU) session, and the VMR device includes a first terminal device and an access network device.

19. The method according to claim 18, wherein Before the sending the first message to the VMR device, the method further includes: Receive a second request message from the VMR device, where the second request message is used to request the establishment of an N2 connection between the VMR device and the second network element, and the first message is a response message to the second request message.

20. The method according to claim 19, wherein The second request message further includes first indication information, where the first indication information is used to trigger the second network element to return the identification information of the first UPF.

21. The method according to claim 20, wherein The first indication information includes at least one of the following: The location information of the VMR device; The capabilities of the VMR device, where the capabilities are that the VMR device has the ability to establish an N3 connection with the UPF using a PDU session; The identification information of the UPF that requests to establish an N3 connection through a PDU session.

22. The method according to any one of claims 18 to 21, characterized in that, Before sending the first message to the VMR device, the method further includes: Send a fifth request message to a third network element, where the fifth request message is used to request to query the identification information of the first UPF; Receive a seventh message from the third network element, where the seventh message includes the identification information of the first UPF.

23. The method according to claim 22, wherein The fifth request message further includes the location information of the VMR device.

24. The method according to any one of claims 18 to 23, characterized in that, The method further includes: Save the second corresponding relationship between the identification information of the VMR device and the first UPF.

25. The method according to claim 24, wherein The method further includes: Receive a sixth request message from the VMR device, where the sixth request message is used to request the establishment of a second PDU session, the second PDU session is established by a second terminal device through the VMR device, the second PDU session is associated with the first UPF, and the second terminal device is currently accessing the VMR device; Determine the first UPF according to the sixth request message and the second corresponding relationship; Send the identification information of the first UPF to a fourth network element.

26. A communication device, characterized in that, Includes: A module or unit for executing the method according to any one of claims 1 to 25.

27. A communication device, characterized in that, Includes: A processor and a memory, where the processor is coupled to the memory, and the memory is used to store a computer program. When the computer program is executed by the processor, the device executes the method according to any one of claims 1 to 25.

28. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium. When the computer program runs on a computer, the computer executes the method according to any one of claims 1 to 25.

29. A computer program product, characterized in that, Includes: A computer program. When the computer program runs on a computer, the computer executes the method according to any one of claims 1 to 25.

30. A chip, characterized in that, Includes: A processor and a memory, where the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, so that the device or equipment installed with the chip executes the method according to any one of claims 1 to 25.

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