Communication method and communication apparatus

Abstract

Provided in the present application is a communication method, comprising: a host access network device or a relay device determines that a camped cell of the relay device is located outside a service area of a first network slice, wherein the first network slice is associated with a first PDU session established by the relay device, a DRB corresponding to the first PDU session is used for bearing data of a backhaul link, and the backhaul link is a backhaul link for data transmission of a second PDU session of a first terminal device connected to the relay device. Thus, the host access network device or the relay device instructs, by means of first instruction information, a first core network device serving the first terminal device to deactivate the second PDU session, thus avoiding service failure or interruption caused by the first terminal device continuing to perform service transmission on the basis of the second PDU session.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 22, 2023, with application number 202311795262.7 and application name “Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communication technology, and more specifically, to a communication method and a communication device. Background Art

[0003] With the development of mobile communication technology, various new services and application scenarios are constantly emerging. These services have very different requirements for network functions, connection performance, and security. If a single network is used to carry these services, it will be difficult to simultaneously meet the requirements of high bandwidth, low latency, and high reliability. In addition, building a new network for each service will incur huge costs. This requires the fifth-generation (5G) communication system to be flexible and scalable while being able to meet different business needs. To this end, 5G communication systems provide users with customized network services through end-to-end network slicing.

[0004] In addition, the layer 3 (L3) relay system includes a relay device, which includes a relay terminal device and a relay network device, wherein the data plane or user plane data of the first terminal device accessing the relay network device is backtransmitted through a data radio bearer (DRB) established between the relay terminal device and the host base station.

[0005] However, when the service area of ​​the network slice associated with the DRB established by the relay device for the first terminal device to carry the backhaul link data does not include the resident cell of the relay device, the request initiated by the relay device in the resident cell to establish a protocol data unit (PDU) session associated with the network slice will fail, or even if there is a PDU session associated with the network slice, the data plane of the PDU session will not be activated and the corresponding established DRB will be released. Therefore, the relay device cannot continue to provide backhaul services to the terminal device through the DRB corresponding to the PDU session associated with the network slice in the resident cell, which may cause the terminal device to request a service to fail or the established service to be interrupted.

[0006] Summary of the Invention

[0007] The present application provides a communication method to avoid failure of a terminal device to request a service or interruption of an established service.

[0008] In a first aspect, a communication method is provided. The method may be performed by a host access network device or a relay device, or by a component (e.g., a chip, circuit, or chip system) of the host access network device or relay device. This application is not limited thereto.

[0009] The communication method includes: determining that a first cell is located outside the service area of ​​a first network slice, the first cell is a resident cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established with the relay device, the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of a second PDU session of a first terminal device, and the first terminal device is a terminal device accessing the relay device; sending a first indication message, the first indication message is used to instruct the first core network device to deactivate the second PDU session, and the first core network device serves the first terminal device.

[0010] Based on the above technical solution, taking the execution of the host access network device or relay device as an example, the host access network device or relay device can determine that the cell where the relay device currently resides is outside the service area of ​​the first network slice, and the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, which is the backhaul link for transmitting data for the second PDU session. Therefore, the host access network device or relay device can instruct the first core network device serving the first terminal device to deactivate the second PDU session through the first indication information, thereby avoiding the first terminal device from continuing to transmit services based on the second PDU session, which may cause service failure or interruption.

[0011] In combination with the first aspect, in certain implementations of the first aspect, determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, determining that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, the first service area information being information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0012] Based on the above technical solution, it is possible to determine that the first cell is located outside the service area of ​​the first network slice in different ways, thereby improving the flexibility of the solution. For example, if the device that determines that the first cell is located outside the service area of ​​the first network slice is a host access network device, then when the host access network device determines that the first cell does not include resources allocated for the first network slice, it is considered that the first cell is located outside the service area of ​​the first network slice; for another example, if the device that determines that the first cell is located outside the service area of ​​the first network slice is a relay device, then the relay device can determine that the identifier of the first cell does not belong to any of the identifiers of at least one cell based on the identifier of the first cell and the first service area information of the first network slice, wherein the first service area information includes the identifier of at least one cell included in the service area of ​​the first network slice; for another example, if the device that determines that the first cell is located outside the service area of ​​the first network slice is a relay device, then when the relay device perceives that the first PDU session is deactivated, it is considered that the first cell is located outside the service area of ​​the first network slice.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the sending of the first indication information includes: sending the first indication information to the second core network device, the first indication information including the identifier of the first core network device, the identifier of the first terminal device and the identifier of the second PDU session, the first indication information being used to instruct the second core network device to instruct the first core network device to deactivate the second PDU session, wherein the second core network device serves the relay device.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the sending of the first indication information includes: sending the first indication information to the first core network device, the first indication information including the identifier of the first terminal device and the identifier of the second PDU session.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the sending of the first indication information includes: sending the first indication information to the first terminal device, the first indication information including the identifier of the second PDU session, and the first indication information is used to instruct the first terminal device to initiate deactivation of the second PDU session to the first core network device.

[0016] Based on the above technical solution, the host access network device or relay device sends the first indication information, which can be: the host access network device or relay device sends the first indication information to the second core network device to instruct the second core network device to instruct the first core network device to deactivate the second PDU session; or, the first indication information can be sent directly to the first core network device; or, the first indication information can be sent to the first terminal device to instruct the first terminal device to instruct the first core network device to deactivate the second PDU session, etc. The first core network device can be instructed to deactivate the second PDU session in different ways to improve the flexibility of the solution.

[0017] In combination with the first aspect, in some implementations of the first aspect, the method further includes: releasing resources configured for the second PDU session.

[0018] In combination with the first aspect, in certain implementations of the first aspect, before releasing the resources configured for the second PDU session, the method further includes: receiving second indication information, where the second indication information is used to indicate the release of the resources configured for the second PDU session.

[0019] In a second aspect, a communication method is provided. The method may be performed by a first core network device, or by a component of the first core network device (e.g., a chip, circuit, or chip system). This application is not limited to this. For example, the first core network device is a core network device serving a first terminal device, such as an AMF that manages the first terminal device.

[0020] The communication method includes: receiving indication information for deactivating the second protocol data unit (PDU) session of the first terminal device; deactivating the second PDU session, wherein the data radio bearer (DRB) corresponding to the first PDU session established by the relay device is used to carry data of the backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session, the first PDU session is associated with the first network slice, and the resident cell of the relay device is located outside the service area of ​​the first network slice.

[0021] Based on the above technical solution, after receiving the indication information instructing to deactivate the second PDU session, the core network device serving the first terminal device executes the process of deactivating the second PDU in response to the indication information, thereby avoiding the situation where the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link (the backhaul link is the backhaul link for transmitting data of the second PDU session), and the first terminal device continues to transmit services based on the second PDU session, resulting in service failure or interruption.

[0022] In combination with the second aspect, in certain implementations of the second aspect, the receiving of indication information for deactivating the second PDU session of the first terminal device includes: receiving the indication information from at least one of the following devices: the relay device, the host access network device, the second core network device, or the first terminal device, wherein the second core network device serves the relay device, and the indication information includes an identifier of the first terminal device and an identifier of the second PDU session.

[0023] Based on the above technical solution, the first core network device can receive instructions from any one or more devices including the relay device, the host access network device, the second core network device, or the first terminal device to deactivate the second protocol data unit PDU session of the first terminal device, thereby improving the flexibility of the solution.

[0024] In combination with the second aspect, in some implementations of the second aspect, the method further includes: sending second indication information, where the second indication information is used to indicate the release of resources configured for the second PDU session.

[0025] In a third aspect, a communication method is provided. The method may be performed by a second core network device, or by a component of the second core network device (e.g., a chip, circuit, or chip system). This application is not limited to this. For example, the second core network device is a core network device serving a relay device, such as an AMF that manages the relay device.

[0026] The communication method includes: receiving first indication information, the first indication information including an identifier of a first core network device, an identifier of a first terminal device and an identifier of a second protocol data unit PDU session; sending sixth indication information in response to the first indication information, the sixth indication information being used to instruct the first core network device to deactivate the second PDU session, wherein a data radio bearer DRB corresponding to the first PDU session established by the relay device is used to carry data of a backhaul link, the backhaul link being a backhaul link for transmitting data of the second PDU session, the first PDU session being associated with a first network slice, and the resident cell of the relay device being located outside the service area of ​​the first network slice.

[0027] Based on the above technical solution, after receiving the indication information instructing the first core network device to deactivate the second PDU session, the core network device serving the relay device sends the sixth indication information to the first core network device in response to the indication information to deactivate the second PDU session, thereby avoiding the situation where the DRB corresponding to the first PDU session associated with the first network slice established by the relay device cannot continue to be used to carry data on the backhaul link (the backhaul link is the backhaul link for transmitting data of the second PDU session), and the first terminal device continues to transmit services based on the second PDU session, resulting in service failure or interruption.

[0028] In combination with the third aspect, in certain implementations of the third aspect, the receiving of the first indication information includes: receiving the first indication information from the relay device and / or the host access network device.

[0029] In combination with the third aspect, in some implementations of the third aspect, the method further includes: deactivating the first PDU session.

[0030] In a fourth aspect, a communication method is provided. The method can be executed by a first terminal device, or by a component of the first terminal device (such as a chip, circuit, or chip system). This application is not limited to this.

[0031] The communication method includes: receiving first indication information, wherein the first indication information includes an identifier of a second protocol data unit (PDU) session; sending seventh indication information to a first core network device in response to the first indication information, wherein the seventh indication information includes an identifier of the second PDU session, and the seventh indication information is used to indicate deactivation of the second PDU session, wherein a data radio bearer (DRB) corresponding to the first PDU session established by the relay device is used to carry data of a backhaul link, and the backhaul link is a backhaul link for transmitting data of the second PDU session, the first PDU session is associated with a first network slice, and the resident cell of the relay device is outside the service area of ​​the first network slice.

[0032] Based on the above technical solution, after receiving the indication information instructing the first core network device to deactivate the second PDU session, the first terminal device sends the seventh indication information to the first core network device in response to the indication information to deactivate the second PDU session, thereby avoiding the situation where the DRB corresponding to the first PDU session associated with the first network slice established by the relay device cannot continue to be used to carry data on the backhaul link (the backhaul link is the backhaul link for transmitting data of the second PDU session), and the first terminal device continues to transmit services based on the second PDU session, resulting in service failure or interruption.

[0033] In combination with the fourth aspect, in certain implementations of the fourth aspect, the receiving of the first indication information includes: receiving the first indication information from the relay device and / or the host access network device.

[0034] In a fifth aspect, a communication method is provided. The method can be performed by a second core network device, or by a component of the second core network device (e.g., a chip, circuit, or chip system). This application is not limited to this. For example, the second core network device is a core network device serving a relay device, such as the second core network device is an AMF that manages the relay device.

[0035] The communication method includes: receiving third indication information, the third indication information is used to indicate the deactivation of the first protocol data unit PDU session, the data radio bearer DRB corresponding to the first PDU session is used to carry data of the backhaul link, the backhaul link is the backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device; in response to the third indication information, the network slice associated with the first PDU session is updated from the first network slice to the second network slice, the second network slice has available resources in the first cell, the first cell is the resident cell of the relay device, and the first cell is located outside the service area of ​​the first network slice; sending a first message, the first message is used to indicate the second network slice associated with the first PDU session.

[0036] Based on the above technical solution, in a scenario where the resident cell where the relay device is currently located is outside the service area of ​​the first network slice, after the core network device serving the relay device receives the third indication information instructing to deactivate the first PDU session, it determines that the first network slice associated with the first PDU session has no configured resources in the first cell, and thus, in response to the third indication information, the network slice associated with the first PDU session is updated from the first network slice to the second network slice, and the second network slice has available resources in the first cell, so that the DRB corresponding to the first PDU session associated with the second network slice can continue to provide a backhaul link for the second PDU session of the first terminal device, so that the first terminal device can continue to transmit services based on the second PDU session.

[0037] In a sixth aspect, a communication method is provided. The method can be performed by a host access network device or a relay device, or by a component (e.g., a chip or circuit or chip system) of the host access network device or relay device. This application is not limited to this.

[0038] The communication method includes: determining that a first cell is located outside a service area of ​​a first network slice, the first cell is a resident cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established with the relay device, and the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of a second PDU session of a first terminal device, and the first terminal device is a terminal device accessing the relay device; determining that a DRB corresponding to a third PDU session is used to carry data of the backhaul link; wherein the third PDU session is associated with a third network slice, and the third network slice has available resources in the first cell.

[0039] Based on the above technical solution, taking the execution of the host access network device or relay device as an example, the host access network device or relay device can determine that the cell where the relay device currently resides is located outside the service area of ​​the first network slice. The DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, which is the backhaul link for transmitting data for the second PDU session. Therefore, the host access network device or relay device can select the DRB corresponding to the third PDU session associated with another third network slice with resources configured in the first cell to carry data on the backhaul link, thereby allowing the first terminal device to continue to transmit services based on the second PDU session.

[0040] In combination with the sixth aspect, in certain implementations of the sixth aspect, determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, determining that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, the first service area information being information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0041] In a seventh aspect, a communication method is provided. The method can be performed by a relay device or by a component of the relay device (such as a chip or circuit or chip system). This application is not limited to this.

[0042] The communication method includes: the relay device sets the identifier of the resident cell provided by the relay device to the first terminal device as the identifier of the first cell, the first cell is the resident cell of the relay device, and the first terminal device is a terminal device accessing the relay device.

[0043] Based on the above technical solution, the resident cell of the first terminal device is provided by the relay device. In this technical solution, the relay device can keep the identifier of the resident cell provided by the relay device consistent with the identifier of the resident cell where the relay device is currently located. It can be understood that the resident cell of the terminal device accessing the relay device is an extension of the resident cell of the relay device. If the resident cell where the relay device is currently located is not within the service area of ​​a certain network slice, the terminal device accessing the relay device can also know that the resident cell where it is currently located is not within the service area of ​​a certain network slice.

[0044] In combination with the seventh aspect, in certain implementations of the seventh aspect, before the relay device sets the identifier of the resident cell provided by the relay device as the identifier of the first cell, the method also includes: the relay device determines that the first cell is located outside the service area of ​​the first network slice, the first network slice is associated with the first protocol data unit PDU session established by the relay device, and the data radio bearer DRB corresponding to the first PDU session serves as a backhaul link for transmitting data for the second PDU session of the first terminal device, and the backhaul link is used to carry data between the relay device and the host access network device.

[0045] In an eighth aspect, a communication method is provided. The method can be performed by a first core network device, or by a component of the first core network device (e.g., a chip, a circuit, or a chip system). This application is not limited to this. For example, the first core network device is a core network device serving the first terminal device, such as the first core network device is an AMF that manages the first terminal device.

[0046] The communication method includes: receiving indication information for updating second service area information, where the second service area information is information indicating the service area of ​​a fourth network slice provided by a first core network device serving a first terminal device; updating the second service area information in response to the indication information, where the updated second service area information does not include an identifier of a second cell, where the second cell is a resident cell provided by a relay device for the first terminal device; and sending the updated second service area information to the first terminal device.

[0047] Based on the above technical solution, after receiving the indication information instructing to update the second service area information, the first core network device updates the second service area information so that the updated second service area information does not include the identifier of the second cell, and sends the updated second service area information to the first terminal device, so that the first terminal device can determine that the second cell is located outside the service area of ​​the fourth network slice based on the updated second service area information. Therefore, when the resident cell of the first terminal device is the second cell, the second PDU session associated with the fourth network slice established by the first terminal device needs to be deactivated, thereby avoiding the first terminal device continuing to transmit services based on the second PDU session, which may cause service failure or interruption.

[0048] In combination with the eighth aspect, in certain implementations of the eighth aspect, the receiving of indication information for updating the second service area information includes: receiving the indication information from at least one of the following devices: the relay device, the host access network device, or the first terminal device.

[0049] Based on the above technical solution, the first core network device can receive indication information from any one or more devices including the relay device, the host access network device, or the first terminal device to update the second service area information, thereby improving the flexibility of the solution.

[0050] In a ninth aspect, a communication method is provided. The method can be performed by a host access network device or a relay device, or by a component (e.g., a chip or circuit or chip system) of the host access network device or relay device. This application is not limited to this.

[0051] The communication method includes: determining that a first cell is located outside a service area of ​​a first network slice, the first cell is a resident cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established with the relay device, the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session, and the first terminal device is a terminal device accessing the relay device; sending fourth indication information, the fourth indication information is used to instruct the first core network device to update second service area information, the first core network device serves the first terminal device, and the second service area information is information indicating the service area of ​​the fourth network slice provided by the first core network device.

[0052] In combination with the ninth aspect, in certain implementations of the ninth aspect, determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, determining that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, the first service area information being information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0053] In combination with the ninth aspect, in certain implementations of the ninth aspect, the sending of the fourth indication information includes: sending the fourth indication information to the first core network device and / or the first terminal device.

[0054] In a tenth aspect, a communication method is provided. The method can be executed by a first terminal device, or by a component of the first terminal device (such as a chip, circuit, or chip system). This application is not limited to this.

[0055] The communication method includes: sending fifth indication information, wherein the fifth indication information is used to instruct the first core network device to update second service area information, wherein the second service area information is information indicating the service area of ​​the fourth network slice provided by the first core network device, and the first core network device is a core network device serving the first terminal device; receiving updated second service area information, wherein the updated second service area information does not include an identifier of a second cell, and the second cell is a resident cell provided by the relay device for the first terminal device.

[0056] In combination with the tenth aspect, in certain implementations of the tenth aspect, before sending the fifth indication information, the method also includes: receiving fourth indication information from the relay device and / or the host access network device, and the fourth indication information is used to instruct the first core network device to update the second service area information.

[0057] In an eleventh aspect, a communication method is provided. The method can be executed by a first terminal device, or by a component of the first terminal device (e.g., a chip, circuit, or chip system). This application is not limited to this.

[0058] The communication method includes: a first terminal device receives eighth indication information, and the eighth indication information is used to indicate that the second cell does not belong to the service area of ​​the fourth network slice; the first terminal device determines, in response to the eighth indication information, that the second cell is not regarded as a cell within the service area of ​​the fourth network slice, or the first terminal device removes the second cell from the service area of ​​the fourth network slice in response to the eighth indication information, wherein the second cell is a resident cell provided by a relay device, and the service area of ​​the fourth network slice is at least one cell indicated by the second service area information provided by the first core network device serving the first terminal device, and the at least one cell includes the second cell, and the first terminal device is a terminal device accessing the relay device.

[0059] In a twelfth aspect, a communication device is provided. The communication device may be a first device, or a module or unit (e.g., a chip, or a chip system, or a circuit) in the first device that corresponds to the method, operation, step, or action described in aspects 1 to 11 and any of their embodiments, or may be compatible with the first device.

[0060] Exemplarily, the first device may be the host access network device or relay device of the first, sixth or ninth aspect above, or a component of the host access network device or relay device (such as a chip or circuit or chip system), and the first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the first, sixth or ninth aspect and any one of its embodiments, and a processing module or unit for performing the processing operations / steps / actions described in the first, sixth or ninth aspect and any one of its embodiments.

[0061] Exemplarily, the first device can be the first core network device of the second aspect or the eighth aspect or a component of the first core network device (such as a chip or circuit or chip system) mentioned above, and the first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the second aspect, the eighth aspect and any one of their embodiments, and a processing module or unit for performing the processing operations / steps / actions described in the second aspect, the eighth aspect and any one of their embodiments.

[0062] Exemplarily, the first device may be the second core network device of the third aspect or the fifth aspect or a component of the second core network device (such as a chip or circuit or chip system) mentioned above, and the first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the third aspect, the fifth aspect and any one of their embodiments, and a processing module or unit for performing the processing operations / steps / actions described in the third aspect, the fifth aspect and any one of their embodiments.

[0063] Exemplarily, the first device may be the first terminal device or a component of the first terminal device (such as a chip or circuit or chip system) of the fourth aspect, the tenth aspect or the eleventh aspect mentioned above, and the first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the fourth aspect, the tenth aspect or the eleventh aspect and any one of its embodiments, and a processing module or unit for performing the processing operations / steps / actions described in the fourth aspect, the tenth aspect or the eleventh aspect and any one of its embodiments.

[0064] Exemplarily, the first device can be the relay device of the seventh aspect mentioned above, or a component of the relay device (such as a chip or circuit or chip system), and the first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the seventh aspect and any one of its embodiments, and a processing module or unit for performing the processing operations / steps / actions described in the seventh aspect and any one of its embodiments.

[0065] In a thirteenth aspect, a communication device is provided. The communication device is used to perform the method provided by the first to eleventh aspects and any of their embodiments. Specifically, the communication device may include units and / or modules (e.g., processing units, transceiver units) for performing the method provided by the first to eleventh aspects and any of their embodiments.

[0066] In one implementation, the communication device is a device. The transceiver unit may be a transceiver or an input / output interface. The processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0067] In another implementation, the communication device may be a chip, chip system, or circuit in a device. In this case, the transceiver unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0068] In a fourteenth aspect, the present application provides a processor for executing the methods provided in the first to eleventh aspects above.

[0069] For the operations such as sending and acquiring / receiving involved in the processor, unless otherwise specified, or if they do not conflict with their actual functions or internal logic in the relevant descriptions, they can be understood as processor output, reception, input and other operations, and can also be understood as sending and receiving operations performed by the radio frequency circuit and antenna. This application does not limit this.

[0070] In a fifteenth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, which, when executed on a communication device, causes the communication device to execute the method of any one of the implementations of the first to eleventh aspects.

[0071] In a sixteenth aspect, a computer program product comprising instructions is provided. When the computer program product is run on a computer, the computer is caused to execute the method provided in any one of the implementations of the first to eleventh aspects.

[0072] In the seventeenth aspect, a chip is provided, which includes a processor and a communication interface. The processor reads instructions through the communication interface and executes the method provided by any one of the implementation methods of the first to eleventh aspects above.

[0073] Optionally, as an implementation method, the chip also includes a memory, the memory stores a computer program or instructions, and the processor is used to execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the processor is used to execute the method provided in any one of the implementation methods of the first to sixth aspects above.

[0074] In the eighteenth aspect, a communication system is provided, comprising a host access network device or a relay device that executes a method according to any one of the implementation modes of the first aspect, a first core network device that executes a method according to any one of the implementation modes of the second aspect, a second core network device that executes a method according to any one of the implementation modes of the third aspect, and a first terminal device that executes a method according to any one of the implementation modes of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIG1 is a schematic diagram of a communication system 100 to which an embodiment of the present application is applicable.

[0076] Figure 2 is a schematic diagram of the network slicing service area provided by this application.

[0077] FIG3 is a schematic diagram of the relay architecture provided in this application.

[0078] FIG4 is a schematic diagram of data transmission in an L3 Relay system provided by the present application.

[0079] FIG5 is a schematic flow chart of a communication method provided in this application.

[0080] FIG6 is a schematic flow chart of another communication method provided in the present application.

[0081] FIG7 is a schematic flowchart of another communication method provided in the present application.

[0082] FIG8 is a schematic flowchart of another communication method provided in this application.

[0083] FIG9 is a schematic flowchart of another communication method provided in this application.

[0084] FIG10 is a schematic flowchart of another communication method provided in the present application.

[0085] FIG11 is a schematic flowchart of another communication method provided in the present application.

[0086] FIG12 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application.

[0087] FIG13 is a schematic diagram of another communication device 20 provided in an embodiment of the present application.

[0088] FIG14 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0089] In order to facilitate understanding of the embodiments of the present application, the following explanations are made.

[0090] First, in this application, "used to indicate" can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must include A.

[0091] The information indicated by the indication information is referred to as the information to be indicated. During the specific implementation process, there are many ways to indicate the information to be indicated. The information to be indicated can be sent as a whole or divided into multiple sub-information and sent separately. The transmission period and / or transmission timing of these sub-information can be the same or different. The specific transmission method is not limited in this application. The transmission period and / or transmission timing of these sub-information can be predefined, for example, according to a protocol, or can be configured by the transmitting device through sending configuration information to the receiving device.

[0092] Second, "at least one" shown in the present application refers to one or more, and "a plurality of" refers to two or more. In addition, in the embodiments of the present application, "first", "second" and various digital numbers (for example, "#1", "#2", etc.) are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. It should be understood that the objects described in this way can be interchangeable under appropriate circumstances, so that the schemes other than the embodiments of the present application can be described. In addition, in the embodiments of the present application, words such as "S501", "S502" are only for the convenience of description and are not used to limit the order of execution of steps.

[0093] Third, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0094] Fourth, the term "storage" used in the embodiments of this application may refer to storage in one or more memories. The one or more memories may be provided separately or integrated into an encoder or decoder, a processor, or a communication device. The one or more memories may also be provided in part separately and in part integrated into a decoder, a processor, or a communication device. The memory may be any type of storage medium, and this application is not limited thereto.

[0095] Fifth, the "protocol" involved in the embodiments of the present application may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems. This application does not limit this.

[0096] Sixth, in the embodiments of the present application, "under the circumstances", "when", and "if" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0097] Seventh, in the embodiments of this application, various terms and English abbreviations, such as radio resource control (RRC), are provided for ease of description and should not constitute any limitation on this application. This application does not exclude the possibility of defining other terms in existing or future protocols that can achieve the same or similar functions.

[0098] Eighth, the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0099] The technical solution in this application will be described below with reference to the accompanying drawings.

[0100] 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), etc. The technical solutions provided in the present application can also be applied to future communication systems, such as the sixth generation mobile communication system. The technical solutions of the embodiments of the present application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication system or other communication systems.

[0101] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application will first be described in detail using the communication system shown in FIG1 as an example. FIG1 is a schematic diagram of a communication system 100 applicable to the embodiments of the present application. As shown in FIG1 , the communication system 100 may include at least one access network device, such as the access network device 110 shown in FIG1 ; the communication system 100 may also include at least one terminal device, such as the terminal device 120 shown in FIG1 ; and the communication system 100 may also include at least one core network (CN) device, such as the core network device 130 shown in FIG1 . The access network device 110 and the terminal device 120 may communicate via a wireless link, and the access network device 110 and the core network device 130 may communicate via a wireless link. Each communication device, such as the access network device 110, the terminal device 120, and the core network device 130, may be configured with multiple antennas. For each communication device in the communication system 100, the configured multiple antennas may include at least one transmit antenna for sending signals and at least one receive antenna for receiving signals. Therefore, communication devices in the communication system 100, such as the access network device 110 and the terminal device 120, can communicate using multi-antenna technology.

[0102] As an example and not a limitation, the access network device and the terminal device in the scenario shown in Figure 1 can communicate in a variety of ways, such as communication between the access network device and the terminal device through a point-to-point transmission method, communication between the access network device and the terminal device through a multi-hop (or relay) transmission method, communication between multiple access network devices and terminal devices through dual connectivity (DC) or multi-connection transmission methods, etc. In the embodiments of the present application, no limitation is imposed on the communication method between the access network device and the terminal device. For example, the transmission between the access network device and the terminal device can be uplink, downlink, access link, backhaul link or sidelink, etc.

[0103] The terminal equipment in the embodiments of the present application may refer to an access terminal, a user unit, a user station, a mobile station, a mobile station, a relay station, a remote station, a remote terminal, a mobile device, a user terminal, a user equipment (UE), a terminal, a wireless communication device, a user agent, or a user device. The terminal equipment may also be 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 capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network, or a terminal device in a future-evolved public land mobile network (PLMN), etc., and the embodiments of the present application are not limited thereto.

[0104] As an example and not a limitation, in the embodiments of the present application, wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0105] Furthermore, in the embodiments of the present application, the terminal device may also be a terminal device in an IoT system, whose main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects humans and machines and things. In the embodiments of the present application, IoT technology can achieve massive connections, deep coverage, and terminal power saving through, for example, narrowband (NB) technology.

[0106] The access network device in the embodiment of the present application can be any device with wireless transceiver capabilities used to communicate with terminal devices. The device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home evolved NodeB (HeNB, or home Node B, HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay device, a wireless backhaul node, a transmission point (TP) or a transmission and reception point (TRP), etc. It can also be a gNB in ​​a 5G, such as NR, system, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DPU). unit, DU), etc., and can also be a device that communicates with a terminal device in a future communication system, such as a gNB in ​​a future communication system.

[0107] In some deployments, a gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that an access network device can be a device that includes one or more of a CU node, a DU node, or an AAU node. In addition, the CU may be classified as a network device in an access network (radio access network, RAN), or may be classified as a network device in a core network (core network, CN), which is not limited in this application.

[0108] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, the wireless access network may also be an ORAN architecture. In the ORAN system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. Any unit of 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.

[0109] The core network equipment part in the embodiment of the present application may include but is not limited to the following NFs: user plane function (UPF), network exposure function (NEF), network function repository function (NRF), policy control function (PCF), unified data management function (UDM), unified data repository function (UDR), network data analytics function (NWDAF), authentication server function (AUSF), access and mobility management function (AMF), session management function (SMF), network slice selection function (NSSF), etc. Among them, AMF, SMF, UPF, NEF, AUSF, NRF, PCF, NSSF, and UDM can be understood as network elements used to implement different functions in the core network, for example, they can be combined into network slices as needed. These core network network elements can be independent devices or integrated into the same device to implement different functions. This application does not limit the specific form of the above network elements.

[0110] It should be understood that the above naming is defined only to facilitate the distinction between different functions and should not constitute any limitation to this application. This application does not exclude the possibility of adopting other naming in 5G networks and other future networks. For example, in future communication networks, some or all of the above network elements may continue to use 5G terminology, or may adopt other names.

[0111] As an example and not a limitation, in an embodiment of the present application, the CN device is used to provide user connection, user management, and service carrying, and provides an interface to the external network as a bearer network. This application mainly involves the AMF network element (or AMF, AMF device, AMF unit, etc.) in the core network. AMF is a control plane network function provided by the operator network, which is responsible for access control and mobility management of terminal devices accessing the operator network, such as mobile status management, allocation of user temporary identity, authentication and authorization of users, and other functions.

[0112] In an embodiment of the present application, a terminal device, an access network device or a core network device includes 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 known as main memory). The operating system can 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. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application. 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, for example, the execution subject of the method provided in the embodiment of the present application can be a terminal device or a network device, or a functional module in the terminal device or network device that can call and execute a program.

[0113] 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 storage 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.

[0114] It should be understood that Figure 1 uses the communication between an access network device and a terminal device, and between an access network device and a core network device, as examples to simply illustrate a communication scenario in which the present application can be applied, and does not limit other scenarios in which the present application can be applied. It should also be understood that Figure 1 is merely a simplified schematic diagram for ease of understanding, and the communication system may also include other network devices or other terminal devices, which are not shown in Figure 1.

[0115] To facilitate understanding of the embodiments of the present application, some basic concepts involved in the present application are briefly described. It should be understood that the basic concepts introduced below are illustrated by taking the basic concepts specified in the NR protocol as an example, but the embodiments of the present application are not limited to being applicable only to NR systems. Therefore, the standard names that appear when describing the NR system as an example are all functional descriptions. The specific names are not limited and only indicate the functions of the device, which can be extended to other systems in the future.

[0116] 1. Network slicing: With the development of mobile communication technology, various new services and application scenarios are constantly emerging. These services have very different requirements for network functions, connection performance, and security. If a single network is used to carry these services, it will be difficult to simultaneously meet the requirements of high bandwidth, low latency, and high reliability. In addition, building a new network for each service will incur huge costs. This requires 5G to be flexible and scalable while being able to meet different business needs. To this end, 5G provides users with customized network services through end-to-end network slicing (also referred to as "slicing"). Through flexible allocation of network resources and on-demand networking, 5G virtualizes multiple logical subnets with different characteristics and isolation on the same physical infrastructure to provide targeted services to users.

[0117] Different logical subnets are identified and distinguished by single network slice selection assistance information (S-NSSAI).

[0118] For example, each S-NSSAI may include the following:

[0119] 1) Slice service type (SST): used to point to slice-specific features and service types;

[0120] 2) Slice Differentiator (SD): As a supplement to SST, it can further distinguish multiple network slice instances that meet the same SST. This SD is optional content of S-NSSAI.

[0121] It should be understood that NSSAI hereinafter refers to one or more S-NSSAIs.

[0122] For NSSAI, there are the following categories:

[0123] 1) Subscribed NSSAI: Subscription data belonging to the user;

[0124] 2) Default NSSAI: Depending on the operator's policy, one or more of the user's subscribed NSSAIs may be set as the default NSSAI. If the UE does not carry an allowed NSSAI in the registration request message, and if a default NSSAI exists, the network may use the default NSSAI to provide services to the UE.

[0125] 3) Requested NSSAI: refers to the allowed NSSAI or configured NSSAI carried by the UE in the registration request message.

[0126] 4) Allowed NSSAI: Indicates which S-NSSAIs among the NSSAIs requested by the UE are allowed by the network. The network can indicate the allowed NSSAI to the UE through the "allowed NSSAI" information element (IE) in the registration accept message.

[0127] 5) Configured NSSAI: This refers to the NSSAI that the network configures for the UE. After receiving the configuration parameters indicating the configured NSSAI, the UE learns which S-NSSAIs are available on the network based on the configuration parameters. The network can indicate the configured NSSAI to the UE via the "Configured NSSAI" IE in the registration accept.

[0128] 6) Rejected NSSAI: Indicates which S-NSSAIs among the NSSAIs requested by the UE are rejected by the network, for example, because the core network or access network does not support these S-NSSAIs.

[0129] 7) Partially allowed NSSAI: Similar to the concept of allowed NSSAI above, the difference is that partially allowed NSSAI is supported by some TAs in the UE's RA.

[0130] 8) Partially rejected NSSAI: Similar to the concept of rejected NSSAI above, the difference is that some TAs in the RA of the UE are not supported for the partially rejected NSSAI.

[0131] Specifically, the list of slices supported by the access network device is pre-configured by operation, administration and maintenance (OAM) according to the granularity of tracking area (TA), that is, all cells in a specific TA support the same slices. For example, a TA includes one or more cells. The access network device can report the slice list to the core network when establishing a communication interface (such as NG interface) with the core network. If the access network device can also support CU / DU separation, the DU sends the slice list supported by each TA to the CU, and then the CU reports it to the core network.

[0132] 2. Network slice service area (NS-AoS): Considering that when a slice is deployed and decommissioned within a certain time interval, the UE and network configuration may be affected. For example, when a slice is no longer available or becomes available, this may affect the allowed NSSAI and other parameters, and the registration area (RA) may also need to be changed. Taking Figure 2 as an example, the TA identified by TAC#1 supports network slice #2, and there are a total of 4 cells in the TA. Due to deployment and other reasons, the resources configured by Cell#2 for network slice #2 are suddenly limited, that is, it can be understood that no resources are configured for network slice #2 in Cell#2, so Cell#2 is actually unable to provide network slice #2 services to the UE. In order to avoid affecting the UE and the network side, NS-AoS is introduced to indicate the service area for a specific slice (an area consisting of one or more cells), with the following characteristics:

[0133] 1) NS-AoS is deployed on the RAN side. The AMF can obtain the NS-AoS configured for each slice in the UE RA through OAM;

[0134] 2) When the UE indicates support for NS-AoS capability, the AMF may send NS-AoS with configured NSSAI to the UE via a registration accept or UE configuration update message;

[0135] 3) After receiving NS-AoS for different slices, the possible behaviors of the UE are:

[0136] If the UE receives an NS-AoS for a requested NSSAI, and the UE initiates a registration request for the slice outside the NS-AoS, the slice will be determined by the AMF as an allowed NSSAI or partially allowed NSSAI;

[0137] If the UE receives an NS-AoS for a rejected NSSAI or a partially rejected NSSAI, the UE can only initiate registration requests for these slices in cells within the NS-AoS range of the above slices;

[0138] If the UE receives an NS-AoS for an allowed NSSAI or a partially allowed NSSAI, the UE can only activate the user plane for the established PDU session within the NS-AoS range of the above slice. For a connected UE, if the target cell when the UE switches is a cell outside the NS-AoS of the slice associated with the established PDU session, the target cell will reject the PDU session during the handover process, that is, it will not prepare RAN side resources for the PDU session, and will instruct the AMF to notify the SMF to deactivate the PDU session through an NGAP message.

[0139] 3. Network slice access layer group (NSAG): The access network device can notify the UE of the cell reselection priority and specific random access parameters for the slice by broadcasting. The above information is respectively contained in the system information block 16 (SIB16) and SIB1. Taking into account that the broadcast based on the slice granularity may bring relatively large overhead to the SIB, the concept of network slice group (or NSAG) is proposed, that is, one or more network slices are grouped and identified. Specifically, one or more S-NSSAIs can be mapped to a specific NSAG ID, and the mapping relationship between the NSAG ID and the S-NSSAI is unique within a specific area.

[0140] 4. Relay architecture: The relay architecture includes a relay node, which includes a relay terminal device part and a relay network device part. The relay terminal device part can be represented as the UE part, and the relay network device part can be represented as the base station part (such as gNB). The relay device can be understood as a device consisting of a UE and a gNB. Among them, an air interface connection is established between the UE part of the relay device (which can be called a mobile terminal (relay-MT)) and the donor base station (donor-gNB). This air interface connection can be called the Un interface. A communication interface (such as the Xn interface and the NG interface) exists between the gNB part of the relay device (which can be called the relay-gNB) and the donor-gNB. The control plane and user plane data on the Xn interface and the NG interface can be transmitted using the DRB on the air interface between the relay-MT and the donor-gNB. It should be understood that the communication interface names involved in this application (such as the Un interface, Xn interface, NG interface, etc.) are all examples and do not constitute any limitation on the scope of protection of this application. The names of the communication interfaces may also be other cases, which are not repeated here.

[0141] For example, in the above example, the control plane and user plane data on the relay device are encapsulated in the user plane data of the relay-MT and sent to the donor-gNB. At this time, the relay-MT's mission has been completed. The donor-gNB will maintain a bearer mapping relationship and map the relay-MT's DRB again to the general packet radio system (GPRS) tunneling protocol user plane (GTP-U) tunnel of the UE accessing the relay device (for the user plane) or the S1AP tunnel of the relay-gNB (for the control plane).

[0142] Exemplarily, the above-mentioned relay device has complete gNB functions, that is, it has a complete base station side protocol stack. The relay architecture in this application can be called NR Layer 3 Relay (NR L3 Relay).

[0143] To facilitate understanding, the architecture of the NR L3 Relay system is briefly introduced with reference to Figure 3.

[0144] As can be seen from Figure 3, the NR L3 Relay system includes core network equipment (such as the AMF / UPF shown in Figure 3), access network equipment (such as the donor base station (donor-gNB) and base station (gNB) shown in Figure 3), relay equipment (such as the relay shown in Figure 3, which includes relay-MT and relay-gNB) and terminal equipment (such as the UE shown in Figure 3), wherein there is a communication interface between the UE and the relay-gNB of the relay device (such as the Uu interface shown in Figure 3), and there is a communication interface between the relay-MT of the relay device and the donor base station (such as the Un interface shown in Figure 3).

[0145] 5. Data transmission in the L3 Relay system: In the NR system, the establishment of a UE's DRB is triggered by the UE's PDU session establishment. In other words, in the NR system, the base station will only establish a DRB for the corresponding QoS when the UE wants to initiate a service. Direct triggering of DRB establishment by the base station is not currently supported.

[0146] As can be seen from the above, relay devices include relay-MT and relay-gNB. Among them, the relay-MT can be connected to the donor base station through an air interface connection, and the control plane or user plane data of the UE accessing the relay-gNB can be backhauled through the DRB established between the relay-MT and the donor-gNB. Specifically, the relay-MT provides the UE with a PDU session corresponding to the backhauled DRB, which can be triggered by the UE's service. Assuming that the UE wants to establish a PDU session associated with Slice#1, the relay-MT can trigger the establishment of the PDU session based on the UE's PDU session establishment request. The slice identifier associated with the PDU session can be consistent with the service requested by the UE (i.e., Slice#1) or inconsistent, without limitation, thereby realizing the establishment of the DRB between the relay-MT and the donor-gNB to provide relay backhaul services for the UE.

[0147] The above, in combination with Figure 1, briefly introduces the scenarios in which the communication method provided in the embodiment of the present application can be applied, as well as the basic concepts that may be involved in the embodiment of the present application. The L3 Relay system and the data transmission method in the L3 Relay system are introduced in the basic concepts. When the UE moves with the relay device to a cell outside the NS-AoS of the slice, the relay-MT of the relay device cannot initiate the establishment of a PDU session request for the slice, or even if there is an associated PDU session, the data plane of the PDU session will not be activated and the corresponding established DRB will be released, which may cause the UE to request the slice service to fail or the established service to be interrupted.

[0148] To facilitate understanding of possible problems with the data transmission method in the above-mentioned L3 Relay system, an explanation is provided below with reference to FIG. 4 .

[0149] As shown in Figure 4, assuming that the TA identified by TAC#1 is the RA of the UE, the list of network slices supported in TA#1 is {network slice#1, network slice#2} ("{}" represents a list), and TA#1 includes three static cells: Cell#1, Cell#2, and Cell#3, of which Cell#1 does not allocate any resources for network slice#1. The relay device is a mobile relay device (such as an on-vehicle relay device, etc.), and the relay-gNB of the relay device includes Cell#4. Cell#4 can support network slice#1 and network slice#2, and resources are allocated to both network slice#1 and network slice#2. Cell#4 moves with the relay device and is not a deployed static cell.

[0150] Assume that the UE accesses the cell of the relay-gNB (i.e., Cell#4), and the UE and relay-MT can receive NS-AoS information from their respective AMFs. For example, the NS-AoS information of network slice #1 received by the UE from the AMF serving the UE includes the cell identifiers of Cell#2, Cell#3, and Cell#4 (such as the NCGI of the cell), and the NS-AoS information of network slice #1 received by the relay-MT from the AMF serving the relay-MT includes the cell identifiers of Cell#2 and Cell#3.

[0151] When the UE moves with the relay device to a cell (such as Cell#1) outside the NS-AoS of a specific slice (such as network slice #1), the relay-MT cannot initiate the establishment of a PDU session request for the network slice #1, or even if there is a PDU session #1 associated with network slice #1, the data plane of the PDU session #1 will not be activated, and the established DRB corresponding to the PDU session #1 will be released. In other words, the relay-MT cannot provide backhaul services for the UE through the DRB corresponding to the PDU session #1. However, for a UE residing on a relay device (e.g., the access network device part (relay-gNB) of a relay device), the serving cell is the cell (i.e., Cell#4) of the relay device (e.g., the access network device part (relay-gNB) of the relay device) rather than the serving cell (i.e., Cell#1) of the relay device (e.g., the terminal device part (relay-MT) of the relay device). At this time, the UE will believe that it is still within the NS-AoS of network slice #1 and is unaware that the backhaul DRB between the relay device (e.g., the terminal device part (relay-MT) of the relay device) and the host base station has been released, which may cause the UE's service request to fail or the established service to be interrupted.

[0152] The present application provides a communication method, when a relay device moves to a cell outside the NS-AoS of a specific slice, how to let the UE accessing the relay device know that the backhaul DRB established for it by the relay device (e.g., the terminal device part (relay-MT) of the relay device) has been released or the relay device (e.g., the terminal device part (relay-MT) of the relay device) is unable to establish a DRB for backhaul for the UE's service, so that the UE can determine the subsequent correct UE behavior to reduce the failure rate of the UE requesting the slice service and improve service continuity.

[0153] It should be understood that the communication method provided in the embodiments of the present application can be applied to a relay system, for example, the communication system shown in FIG3 .

[0154] It should also be understood that the embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of the present application. As long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application. For example, the execution subject of the method provided in the embodiments of the present application can be a device or a network element, or a functional module in the device or network element that can call and execute the program.

[0155] FIG5 is a schematic flow chart of a communication method provided by the present application, which includes the following steps:

[0156] S501, the first terminal device sends a request message #1 to the first core network device, and accordingly, the first core network device receives the request message #1 from the first terminal device.

[0157] The first core network device involved in this embodiment can be the AMF mentioned above. The name of the first core network device in this embodiment is not limited. Devices that can implement the functions of the first core network device in this embodiment are all within the protection scope of this application. For the convenience of description, the first core network device is AMF#1 as an example. The first terminal device in this embodiment can be any terminal device. For the convenience of description, the first terminal device is UE#1 as an example.

[0158] Specifically, the request message #1 is used to request the establishment of a second PDU session associated with the fourth network slice. Exemplarily, the request message #1 may be an uplink NAS message including a PDU session establishment request message.

[0159] As can be seen from the above, in this embodiment, UE#1 can initiate a request message #1 to establish a second PDU session associated with the fourth network slice. The request message #1 is carried in the NAS message of UE#1 and sent to the AMF serving the terminal device (referred to as AMF#1). In this embodiment, after AMF#1 receives the request message #1, there are the following two possible methods:

[0160] Method 1: AMF#1 can instruct the relay device to establish DRB#1 corresponding to the second PDU session for UE#1.

[0161] In the case shown in the embodiment 1, the method flow shown in FIG5 may further include:

[0162] S502, AMF#1 sends message #1 to the relay device.

[0163] Specifically, message #1 is used to instruct the access network device part of the relay device (e.g., relay-gNB) to establish DRB#1 corresponding to the second PDU session for UE#1 (as shown in DRB#1 in Figure 5, that is, the RRC connection endpoint of UE#1 is at the relay device (e.g., the access network device part of the relay device (relay-gNB)), and the relay device (e.g., the access network device part of the relay device (relay-gNB)) generates the NGAP message related to UE#1, and the host access network device transparently transmits the NGAP message of UE#1).

[0164] Optionally, AMF#1 instructs the relay device (e.g., the access network device part of the relay device (relay-gNB)) through an NGAP message (e.g., an initial context setup request message) to establish DRB#1 corresponding to the second PDU session for UE#1.

[0165] S503: The relay device establishes DRB#1.

[0166] In the case shown in mode 1, the GTP-U tunnel corresponding to the second PDU session (such as GTP-U tunnel #1 shown in Figure 5) is established between the relay device (such as the access network device part of the relay device (relay-gNB)) and AMF#1.

[0167] Method 2: AMF#1 can instruct the host access network device to establish DRB#2 corresponding to the second PDU session for UE#1.

[0168] In the case shown in the second embodiment, the method flow shown in FIG5 may further include:

[0169] S504, AMF#1 sends message #2 to the host access network device.

[0170] Specifically, message #2 is used to instruct the host access network device (donor-gNB) to establish DRB#2 corresponding to the second PDU session for UE#1 (as shown in DRB#2 in Figure 5, that is, the RRC connection of UE#1 is terminated at the host access network device, the host access network device generates UE-related NGAP messages, and the relay device transparently transmits the RRC messages of UE#1).

[0171] Optionally, AMF#1 instructs the host access network device to establish DRB#2 corresponding to the second PDU session for UE#1 through an NGAP message (such as an initial context setup request message).

[0172] S505: The host access network device establishes DRB#2.

[0173] In the case shown in mode 2, the GTP-U tunnel corresponding to the second PDU session (GTP-U tunnel #2 as shown in Figure 5) is established between the host access network device and UPF #1 serving UE #1.

[0174] Furthermore, the relay device may initiate, based on the fourth network slice associated with the second PDU session of UE#1, a request to establish a first PDU session associated with the first network slice to the second core network device (e.g., AMF#2) serving the relay device through a NAS message. The fourth network slice and the first network slice may be the same or different. The method flow shown in FIG5 further includes:

[0175] S506, the relay device sends request message #2 to AMF#2, and accordingly, AMF#2 receives request message #2 from the relay device.

[0176] Specifically, the request message #2 is used to request the establishment of a first PDU session associated with the first network slice. Exemplarily, the request message #2 may be an uplink NAS message including a PDU session establishment request message.

[0177] S507, AMF#2 sends message #3 to the host access network device.

[0178] Specifically, the message #3 is used to instruct the host access network device to establish DRB#3 corresponding to the first PDU session for the relay device (e.g., the terminal device part (relay-MT) of the relay device) (as shown in DRB#3 in Figure 5, that is, the RRC connection of the relay device is terminated at the host access network device, and the host access network device generates NGAP messages related to the relay device (e.g., the terminal device part (relay-MT) of the relay device)).

[0179] Optionally, AMF#2 can instruct the host access network device to establish DRB#3 corresponding to the first PDU session for the relay device through an NGAP message (such as an initial context setup request message).

[0180] S508: The host access network device establishes DRB#3.

[0181] The GTP-U tunnel corresponding to the first PDU session (GTP-U tunnel #3 as shown in Figure 5) is established between the host access network device and AMF #2. DRB #3 can be used to carry data on the backhaul link. The backhaul link is the backhaul link for transmitting data for UE #1's second PDU session. Specifically, the backhaul link is used to carry data between the relay device and the host access network device.

[0182] As a possible implementation method, if the relay device moves from Cell#2 to the first cell (such as Cell#1), the resident cell (or service cell) of the relay device (such as the terminal device part of the relay device (relay-MT)) changes from Cell#2 to the first cell.

[0183] Optionally, Cell#1 and Cell#2 belong to the same base station, that is, the first cell and Cell#2 belong to the host access network device, then for the relay device (such as the terminal device part of the relay device (relay-MT)), it is an intra-CU (within the CU) station switching.

[0184] Optionally, Cell#1 and Cell#2 belong to different base stations, that is, the first cell and Cell#2 do not belong to the same host access network device. Then for the relay device (such as the terminal device part of the relay device (relay-MT)), it is an inter-CU (inter-CU) station handover. Compared with the intra-CU station handover, there are additional XnAP-related handover messages, which will not be repeated here.

[0185] As another possible implementation manner, if the resident cell of the relay device is updated to the first cell.

[0186] In this embodiment, there is no limitation on the reason why the relay device is located in the first cell, that is, the resident cell of the relay device is the first cell.

[0187] The method flow shown in FIG5 further includes:

[0188] S510, the relay device or the host access network device determines that the first cell is located outside the service area of ​​the first network slice.

[0189] From the above, it can be seen that the first cell is the resident cell of the relay device, the first network slice is associated with the first PDU session, and the DRB corresponding to the first PDU session (that is, the above-mentioned DRB#3) is used to carry the data of the backhaul link. The backhaul link is the backhaul link for transmitting data of the second PDU session. The backhaul link is used to carry data between the relay device and the host access network device. UE#1 is a terminal device accessing the relay device.

[0190] For example, after the relay device or the host access network device determines that the first cell is located outside the service area of ​​the first network slice, the subsequent process includes the following possible situations shown in 1 to 8, which will be explained one by one in conjunction with the accompanying drawings.

[0191] As a possible implementation manner, the donor access network device performs step S510, that is, the donor access network device determines that the first cell is outside the service area of ​​the first network slice, including:

[0192] The host access network device can determine that no resources are allocated to the first network slice in the resident cell of the relay device, and thus know that the first cell is outside the service area of ​​the first network slice.

[0193] For example, if the host access network device determines that the first cell where the relay device resides (such as the serving cell after switching) has not allocated resources for the first network slice associated with the first PDU session, it can deny admission of the first PDU session, that is, it will not prepare RAN-side resources for the first PDU session. In addition, the host access network device can instruct AMF#2 to notify SMF#2 serving the relay device to deactivate the first PDU session through an NGAP message (for example, the host access network device instructs AMF#2 through an NGAP message, and AMF#2 further instructs SMF#2 to deactivate the first PDU session through the core network internal interface).

[0194] Exemplarily, the NGAP message may be a message related to PDU session modification, such as a PDU session resource notification message or a path switch request message.

[0195] Possibility 1: The host access network device determines to deactivate the second PDU session of UE#1.

[0196] In accordance with the above-described approach 1, the relay device (e.g., the access network device portion of the relay device (relay-gNB)) establishes DRB #1. In the scenario described in possibility 1, the donor access network device may instruct the relay device (e.g., the terminal device portion of the relay device (relay-MT)) to release resources prepared for the second PDU session of UE #1 (including releasing its corresponding DRB #1).

[0197] Corresponding to the above-mentioned approach 2, the host access network device establishes DRB#2. In the case described in possibility 1, the host access network device can directly release the resources prepared for the second PDU session of UE#1.

[0198] If the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device does not complete the release of the resources prepared for the second PDU session of UE#1 (for example, the above-mentioned host access network device instructs the relay device (e.g., the access network device part of the relay device (relay-gNB)) to release the resources prepared for the second PDU session of UE#1 but the instruction is not executed, or the host access network device directly releases the resources prepared for the second PDU session of UE#1 but the instruction is not executed), then in the subsequent process, when AMF#1 deactivates the second PDU session of UE#1, it can also instruct the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device to release the resources prepared for the second PDU session of UE#1 through the second indication information.

[0199] Exemplarily, the situation shown in 1 may involve the host access network device sending an indication to deactivate the second PDU session.

[0200] Optionally, the host access network device sends the deactivation indication in the following ways, including but not limited to, for ease of understanding, which are described below in conjunction with Figure 6.

[0201] Method 1.1: The host access network device instructs AMF#1 to deactivate the second PDU session of UE#1 through AMF#2.

[0202] In the case shown in method 1.1, the method flow shown in FIG6 includes:

[0203] S611, the host access network device sends the first indication information to AMF#2, and accordingly, AMF#2 receives the first indication information from the host access network device.

[0204] Specifically, the first indication information instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0205] Exemplarily, the first indication information may be carried in existing NGAP signaling to indicate AMF#2, or carried in newly added NGAP signaling to indicate AMF#2, which is not limited in this application. For example, the first indication information may be carried in information instructing AMF#2 to deactivate the first PDU session. For example, the first indication information is information instructing AMF#2 to deactivate the first PDU session. If the first indication information is information instructing AMF#2 to deactivate the first PDU session, then in this embodiment, after AMF#2 receives the first indication information, in response to the first indication information, it not only executes the process of deactivating the first PDU session, but also executes the process of instructing AMF#1 to deactivate the second PDU session of UE#1.

[0206] For example, in the case shown in method 1.1, the first indication information includes at least one of the following information:

[0207] The identifier of AMF#1, the identifier of UE#1, or the identifier of the second PDU session.

[0208] Among them, the identifier of AMF#1 is used to notify AMF#2 that the AMF serving UE#1 is AMF#1, and the identifier of AMF#1 can be the globally unique AMF ID (globally unique AMF identifier, GUMAI) of AMF#1; the identifier of UE#1 is used to notify AMF#1 which UE to operate on, and the identifier of the terminal device can be the UE NGAP ID assigned by AMF#1 to UE#1; the identifier of the second PDU session is used to notify AMF#1 which PDU session of the UE to deactivate.

[0209] Optionally, corresponding to the above-mentioned method 1, the first indication information can further provide the UE NGAP ID allocated by the relay device (such as the access network device part of the relay device (relay-gNB)) to UE#1.

[0210] Optionally, corresponding to the above-mentioned method 2, the first indication information may further provide a UE NGAP ID allocated by the host access network device to UE#1.

[0211] It should be noted that the identification of AMF#1, the identification of UE#1, or the identification of the second PDU session involved in this application are only examples and do not constitute any limitation to the scope of protection of this application. For example, the information that can be used to identify the AMF#1 is within the scope of protection of this application. For example, the information that can be used to identify the UE#1 is within the scope of protection of this application. For example, the information that can be used to identify the second PDU session is within the scope of protection of this application. Examples will not be given one by one here.

[0212] S612, AMF#2 sends the sixth indication information to AMF#1, and accordingly, AMF#1 receives the sixth indication information from AMF#2.

[0213] Specifically, AMF#2 can send sixth indication information to AMF#1 based on the first indication information sent by the host access network device, and the sixth indication information instructs AMF#1 to deactivate the second PDU session of UE#1.

[0214] For example, AMF#2 determines that the AMF serving UE#1 is AMF#1 based on the identifier of AMF#1 carried in the first indication information sent by the host access network device, and then sends a sixth indication information to AMF#1. The sixth indication information is used to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0215] Exemplarily, the sixth indication information includes the identifier of UE#1 and the identifier of the second PDU session received from the first indication information.

[0216] Optionally, corresponding to the above-mentioned method 1, the sixth indication information can further provide the UE NGAP ID allocated by the relay device (such as the access network device part of the relay device (relay-gNB)) to UE#1.

[0217] Optionally, corresponding to the above-mentioned mode 2, the sixth indication information may further provide a UE NGAP ID allocated by the host access network device to UE#1.

[0218] S613, AMF#1 deactivates the second PDU session.

[0219] Specifically, in the case shown in method 1.1, after receiving the sixth indication information, AMF#1 deactivates the second PDU session of UE#1 in response to the sixth indication information. For example, AMF#1 determines to deactivate the second PDU session of UE#1 based on the identifier of UE#1 and the identifier of the second PDU session carried in the sixth indication information.

[0220] Method 1.2: The host access network device instructs AMF#1 to deactivate the second PDU session of UE#1.

[0221] In the case shown in method 1.2, the method flow shown in FIG6 further includes:

[0222] S614, the host access network device sends the first indication information to AMF#1, and accordingly, AMF#1 receives the first indication information from the host access network device.

[0223] Specifically, after the host access network device rejects the first PDU session access of the relay device, it instructs AMF#1 to deactivate the second PDU session of UE#1 through the first indication information.

[0224] Exemplarily, in the case shown in method 1.2, the first indication information includes the identifier of UE#1 and the identifier of the second PDU session.

[0225] Optionally, corresponding to the above-mentioned method 1, the first indication information can further provide the UE NGAP ID allocated by the relay device (such as the access network device part of the relay device (relay-gNB)) to UE#1.

[0226] Optionally, corresponding to the above-mentioned method 2, the first indication information may further provide a UE NGAP ID allocated by the host access network device to UE#1.

[0227] S615, AMF#1 deactivates the second PDU session.

[0228] Please refer to the description of step S613 in the above method 1.1, which will not be repeated here.

[0229] Method 1.3: The host access network device instructs UE#1 to initiate deactivation of the second PDU session.

[0230] In the case shown in method 1.3, the method flow shown in FIG6 further includes:

[0231] S616, the host access network device sends first indication information to UE#1, and correspondingly, UE#1 receives the first indication information from the host access network device.

[0232] Specifically, after rejecting the first PDU session admission of the relay device, the host access network device instructs UE#1 to initiate deactivation of the second PDU session through the first indication information.

[0233] Optionally, corresponding to the above-described approach 1, a relay device (e.g., the access network device portion of the relay device (relay-gNB)) establishes DRB#1. The donor access network device sending the first indication information to UE#1 in step S616 may include: the donor access network device sending the first indication information to a relay device (e.g., the terminal device portion of the relay device (relay-MT)), which then sends the first indication information to UE#1 via an RRC message.

[0234] Optionally, corresponding to the above-mentioned mode 2, the host access network device establishes DRB#2. In step S616, the host access network device sends the first indication information to UE#1 by the host access network device directly sending the first indication information to UE#1 via an RRC message.

[0235] S617, UE#1 sends the seventh indication information to AMF#1, and accordingly, AMF#1 receives the seventh indication information from UE#1.

[0236] Specifically, after receiving the above-mentioned first indication information, UE#1 can request AMF#1 to deactivate the second PDU session of UE#1 through the seventh indication information in response to the first indication information.

[0237] Exemplarily, the seventh indication information includes but is not limited to a PDU session release message or a PDU session modification message. It can be understood that the UE can request AMF#1 to deactivate the second PDU session of UE#1 through a PDU session management process (such as a PDU session release or modification process).

[0238] Exemplarily, the seventh indication information includes an identifier of the second PDU session.

[0239] S618, AMF#1 deactivates the second PDU session.

[0240] Please refer to the description of step S613 in the above method 1.1, which will not be repeated here.

[0241] As another possible implementation, the relay device performs step S510, that is, the relay device determines that the first cell is outside the service area of ​​the first network slice, including:

[0242] The relay device determines, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, where the first service area information is information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or

[0243] The relay device determines that the first PDU session is deactivated.

[0244] For example, the relay device can determine that the currently located first cell is outside the NS-AoS of the first network slice based on the NS-AoS information of the first network slice sent by AMF#2. For example, the NS-AoS information of the first network slice (i.e., the above-mentioned first service area information) indicates that the service area of ​​the first network slice includes Cell#2 and Cell#3, then the NS-AoS information of the first network slice includes the identifier of Cell#2 and the identifier of Cell#3, and the above-mentioned identifier of the first cell is not either the identifier of Cell#2 or the identifier of Cell#3. The relay device can determine that the currently located first cell is outside the NS-AoS of the first network slice.

[0245] For another example, the relay device senses that the first PDU session is deactivated by AMF#2. For example, the relay device (e.g., the terminal device part (relay-MT) of the relay device) receives indication information that the first PDU session is deactivated.

[0246] Possibility 2: The relay device determines to deactivate the second PDU session of UE#1.

[0247] In the above-described approach 1, the relay device (e.g., the access network device portion of the relay device (relay-gNB)) establishes DRB #1. In the case described in possibility 2, the relay device (e.g., the access network device portion of the relay device (relay-gNB)) can directly release the resources prepared for the UE's PDU Session #1.

[0248] Corresponding to the above-mentioned approach 2, the host access network device establishes DRB#2. In the case described in possibility 2, the relay device may instruct the host access network device to release the resources prepared for the second PDU session of UE#1.

[0249] If the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device does not complete the release of the resources prepared for the second PDU session of UE#1 (e.g., the relay device directly releases the resources prepared for the second PDU session of UE#1 but the release is not executed, or the above-mentioned relay device instructs the host access network device to release the resources prepared for the second PDU session of UE#1 but the release is not executed), then in the subsequent process, when AMF#1 deactivates the second PDU session of UE#1, it can also instruct the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device to release the resources prepared for the second PDU session of UE#1 through the second indication information.

[0250] Exemplarily, the situation shown in 2 may involve the relay device sending an indication to deactivate the second PDU session.

[0251] Optionally, the relay device sends the deactivation indication in the following ways, which are described below with reference to FIG. 7 for ease of understanding:

[0252] Method 2.1: The relay device instructs AMF#1 to deactivate the second PDU session of UE#1 through AMF#2.

[0253] In the case shown in method 2.1, the method flow shown in FIG7 further includes:

[0254] S721, the relay device sends the first indication information to AMF#2, and accordingly, AMF#2 receives the first indication information from the relay device.

[0255] Specifically, the first indication information instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0256] Exemplarily, the first indication information may be carried in existing NGAP signaling to indicate AMF#2, or carried in newly added NGAP signaling to indicate AMF#2, which is not limited in this application. For example, the first indication information may be carried in information instructing AMF#2 to deactivate the first PDU session. For example, the first indication information is information instructing AMF#2 to deactivate the first PDU session. If the first indication information is information instructing AMF#2 to deactivate the first PDU session, then in this embodiment, after AMF#2 receives the first indication information, in response to the first indication information, it not only executes the process of deactivating the first PDU session, but also executes the process of instructing AMF#1 to deactivate the second PDU session of UE#1.

[0257] For example, in the case shown in method 2.1, the first indication information includes at least one of the following information:

[0258] The identifier of AMF#1, the identifier of UE#1, or the identifier of the second PDU session.

[0259] The definitions of the identifier of AMF#1, the identifier of UE#1, and the identifier of the second PDU session in this embodiment can refer to the description of the identifier of AMF#1, the identifier of UE#1, and the identifier of the second PDU session in step S611 above, and will not be repeated here.

[0260] Optionally, corresponding to the above-mentioned method 1, the first indication information can further provide the UE NGAP ID allocated by the relay device (such as the access network device part of the relay device (relay-gNB)) to UE#1.

[0261] Optionally, corresponding to the above-mentioned method 2, the first indication information may further provide a UE NGAP ID allocated by the host access network device to UE#1.

[0262] S722, AMF#2 sends the sixth indication information to AMF#1, and accordingly, AMF#1 receives the sixth indication information from AMF#2.

[0263] Please refer to the description of step S612 in the above method 1.1, which will not be repeated here.

[0264] S723, AMF#1 deactivates the second PDU session.

[0265] Please refer to the description of step S613 in the above method 1.1, which will not be repeated here.

[0266] Method 2.2: The relay device instructs AMF#1 to deactivate the second PDU session of UE#1.

[0267] In the case shown in method 2.2, the method flow shown in FIG7 further includes:

[0268] S724, the relay device sends the first indication information to AMF#1, and accordingly, AMF#1 receives the first indication information from the relay device.

[0269] Specifically, after the relay device determines that the current resident cell is outside the NS-AoS of the first network slice, the relay device (such as the access network device part of the relay device (relay-gNB)) instructs AMF#1 to deactivate the UE's PDU session #1 through the first indication information.

[0270] Exemplarily, in the case shown in method 2.2, the first indication information includes the identifier of UE#1 and the identifier of the second PDU session.

[0271] Optionally, corresponding to the above-mentioned method 1, the first indication information can further provide the UE NGAP ID allocated by the relay device (such as the access network device part of the relay device (relay-gNB)) to UE#1.

[0272] Optionally, corresponding to the above-mentioned method 2, the first indication information may further provide a UE NGAP ID allocated by the host access network device to UE#1.

[0273] Optionally, corresponding to the above-mentioned method 1, DRB#1 is established by the relay device (e.g., the access network device part of the relay device (relay-gNB)). In step S724, the relay device (e.g., the terminal device part (relay-MT) of the relay device) sends the first indication information to AMF#1. The first indication information may be carried in an NGAP message and transparently transmitted by the relay device (e.g., the access network device part (relay-gNB) of the relay device to AMF#1 through the host access network device.

[0274] Optionally, corresponding to the above-mentioned method 2, DRB#2 is established by the host access network device. In step S724, the relay device (e.g., the terminal device part (relay-MT) of the relay device) sends the first indication information to AMF#1, which may be: the host access network device indicates to AMF#1 through an NGAP message after releasing the resources prepared for the second PDU session of UE#1, wherein the host access network device may indicate to AMF#1 through an NGAP message only after receiving the indication from the relay device (e.g., the terminal device part (relay-MT) of the relay device).

[0275] S725, AMF#1 deactivates the second PDU session.

[0276] Please refer to the description of step S613 in the above method 1.1, which will not be repeated here.

[0277] Method 2.3: The relay device (eg, the terminal device part of the relay device (relay-MT)) instructs UE#1 to initiate deactivation of the second PDU session.

[0278] In the case shown in method 2.3, the method flow shown in FIG7 further includes:

[0279] S726, the relay device sends first indication information to UE#1, and correspondingly, UE#1 receives the first indication information from the relay device.

[0280] Specifically, after determining that the current resident cell is outside the NS-AoS of the first network slice or determining that the first PDU session is activated, the relay device instructs UE#1 to initiate deactivation of the second PDU session through the first indication information.

[0281] S727, UE#1 sends the seventh indication information to AMF#1, and accordingly, AMF#1 receives the seventh indication information from UE#1.

[0282] Please refer to the description of step S617 in the above method 1.3, which will not be repeated here.

[0283] S728, AMF#1 deactivates the second PDU session.

[0284] Please refer to the description of step S613 in the above method 1.1, which will not be repeated here.

[0285] It should be noted that the above-mentioned methods 1.1 to 2.3 all involve first indication information. The receiving end, sending end or content of the first indication information in different methods may be different. In order to distinguish, it can be called first indication information #1, first indication information #2, etc. It should be understood that the message name in this application does not constitute any limitation on the scheme.

[0286] In the solutions shown in Possibility 1 and Possibility 2 above, when the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, the second PDU session can be deactivated by instructing the first core network device serving the first terminal device, thereby avoiding service failure or interruption caused by the first terminal device continuing to transmit services based on the second PDU session.

[0287] In addition, as another implementation method, when the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, the network slice associated with the first PDU session can also be updated from the first network slice to the second network slice. The second network slice has available resources in the first cell, so that the DRB corresponding to the first PDU session associated with the second network slice can continue to provide a backhaul link for the second PDU session of the first terminal device. In this way, the first terminal device can continue to transmit services based on the second PDU session. The following possibility 3 is this implementation method.

[0288] Possibility 3: AMF#2 updates the network slice associated with the first PDU session to a network slice with available resources in the first cell.

[0289] For ease of understanding, the following describes in detail how to update the network slice associated with the first PDU session in the case shown in Possible 3 in conjunction with Figure 8. In the case shown in Possible 3, the method flow shown in Figure 8 includes:

[0290] S831, the host access network device sends the third indication information to AMF#2, and accordingly, AMF#2 receives the third indication information from the host access network device.

[0291] The third indication information is used to instruct to deactivate the first protocol data unit PDU session.

[0292] S832, AMF#2 updates the network slice associated with the first PDU session.

[0293] Specifically, in the case shown in possibility 3, AMF#2 will not deactivate the first PDU session after receiving the third indication information from the host access network device, but will update the network slice associated with the first PDU session, and the updated network slice has available resources in the first cell.

[0294] S833, AMF#2 sends a first message to the host access network device, and accordingly, the host access network device receives the first message from AMF#2.

[0295] After AMF#2 updates the network slice associated with the first PDU session, it can indicate the updated network slice associated with the first PDU session to the host access network device through a first message (e.g., an NGAP message).

[0296] For example, AMF#2 determines to update the first network slice associated with the first PDU session to the second network slice, and indicates it to the host access network device through a PDU session modification request. The updated first PDU session is associated with the second network slice. After receiving the first message, the host access network device can modify the slice associated with the DRB corresponding to the first PDU session to the second network slice.

[0297] For example, AMF#2 may trigger the network slice replacement process for the first network slice, and the second network slice may be regarded as the replacement network slice (alternative S-NSSAI) of the first network slice. The alternative S-NSSAI refers to a slice that is used to replace the unavailable network slice to provide services to the terminal device when the network slice or network slice instance deployed at the core network is congested or unavailable. In this embodiment, it is equivalent to adding a condition for triggering the issuance of the alternative S-NSSAI, that is, AMF#2 will not deactivate the established first PDU session of the relay device (such as the terminal device part (relay-MT) of the relay device) located outside the first network slice NS-AoS, but will trigger the network slice replacement process.

[0298] As another implementation method, when the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry the data of the backhaul link, it is also possible to select the DRB corresponding to the third PDU session associated with other third network slices configured with resources in the first cell to carry the data of the backhaul link, so that the first terminal device can continue to transmit services based on the second PDU session. The following possibility 4 is this implementation method.

[0299] Possibility 4: The host access network device or relay device reselects the DRB for backhaul from other established backhaul DRBs (corresponding to other PDU sessions) for the second PDU session of UE#1.

[0300] If other DRBs for backhaul are established between the host access network device or the relay device, such as the DRB corresponding to the third PDU session, the third PDU session is associated with the third network slice, and there are available resources for the third network slice in the first cell, then the host access network device or the relay device can use the DRB corresponding to the third PDU session as the backhaul link for transmitting data for the second PDU session when it is determined that the resources of the first PDU session on the RAN side have been released.

[0301] Furthermore, the host access network device or relay device can save the association relationship between the DRB associated with the second PDU session and the return DRB (i.e., the DRB corresponding to the above-mentioned third PDU session), and / or, the host access network device or relay device can save the association relationship between the return DRB and the GTP-U tunnel corresponding to the second PDU session.

[0302] As another implementation method, the relay device can keep the identifier of the resident cell provided by the relay device consistent with the identifier of the resident cell where the relay device is currently located. It can be understood that the resident cell of the terminal device accessing the relay device is an extension of the resident cell of the relay device. If the resident cell where the relay device is currently located is not within the service area of ​​a certain network slice, the terminal device accessing the relay device can also know that the resident cell where it is currently located is not within the service area of ​​a certain network slice. The following possibility 5 is this implementation method.

[0303] Possibility 5: The cell where UE#1 resides is an extension of the cell where the relay device resides, that is, the cell identifier of the relay device is consistent with the cell where the relay device resides.

[0304] In the case described in possibility 5, the relay device sets the identifier of the camped cell provided by the relay device for UE#1 as the identifier of the first cell.

[0305] For example, due to the mobility of the relay device, the relay device's resident cell may change. For example, after handover, the relay device's resident cell becomes Cell#1, and the cell identifiers of the relay device are also changed to Cell#1's identifier, that is, Cell#4 is also updated to Cell#1. At this time, the resident cell of UE#1 accessing the relay device is the same as the relay device's resident cell.

[0306] Furthermore, after the relay device updates the cell identifier on the relay device, UE#1 can determine that the current resident cell is not within the service area of ​​the fourth network slice. In this embodiment, the fourth network slice is the same as the first network slice.

[0307] It should be understood that when the terminal device determines that the current resident cell is not within the NS-AoS of the fourth network slice, the subsequent behavior of the terminal device can refer to the behavior description of the terminal device defined in the existing protocol, which will not be repeated here.

[0308] It should be noted that in the case described in possibility 5, the above-mentioned step S510 may be an optional step, that is, the relay device may not need to determine whether the first cell is located outside the service area of ​​the first network slice. When the resident cell of the relay device changes, the relay device may set the identifier of the resident cell provided by the relay device to UE#1 as the identifier of the resident cell of the relay device.

[0309] As another implementation method, when the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, the second service area information can be updated so that the updated second service area information does not include the identifier of the second cell (i.e., the resident cell of the first terminal device), and the updated second service area information is sent to the first terminal device, so that the first terminal device can determine that the second cell is outside the service area of ​​the fourth network slice based on the updated second service area information. Therefore, when the resident cell of the first terminal device is the second cell, the second PDU session associated with the fourth network slice established by the first terminal device needs to be deactivated, thereby avoiding the first terminal device from continuing to transmit services based on the second PDU session, which may cause service failure or interruption. The following possibilities 6 and 7 are this implementation method.

[0310] Possibility 6: The host access network device or relay device instructs AMF#1 to update the NS-AoS of the fourth network slice for UE#1.

[0311] For ease of understanding, the following describes in detail the case shown in Possible 6, in conjunction with Figure 9, in which AMF#1 updates the NS-AoS of the fourth network slice for UE#1. In Possible 6, the method flow shown in Figure 9 includes:

[0312] S921, the host access network device or relay device sends the fourth indication information to AMF#1, and accordingly, AMF#1 receives the fourth indication information from the host access network device or relay device.

[0313] Specifically, the fourth indication information is used to instruct AMF#1 to update the NS-AoS information of UE#1 for the fourth network slice, and the current resident cell of UE#1 (such as Cell#4) should be removed from the updated NS-AoS information.

[0314] Optionally, if the fourth indication information is sent by the relay device, corresponding to the above-mentioned method 1, the relay device (e.g., the access network device part of the relay device (relay-gNB)) establishes DRB#1. Then, the host access network device can transparently transmit it to AMF#1. Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2. Then, the relay device can first indicate it to the host access network device, and then the host access network device can indicate it to AMF#1.

[0315] S922, AMF#1 updates the second service area information.

[0316] Specifically, in response to the fourth indication information, AMF#1 updates the second service area information, where the second service area information is the NS-AoS information of the fourth network slice provided by AMF#1. The updated second service area information does not include the identifier of the second cell (i.e., the current cell where UE#1 resides). For example, the current cell where UE#1 resides (e.g., Cell#4) should be removed from the updated second service area information.

[0317] S923, AMF#1 sends the updated second service area information to UE#1, and accordingly, UE#1 receives the updated second service area information from AMF#1.

[0318] S924, UE#1 determines that the current resident cell is not within the service area of ​​the fourth network slice.

[0319] Specifically, when the terminal device determines that the current resident cell is not within the NS-AoS of the fourth network slice, the subsequent behavior of the terminal device can refer to the behavior description of the terminal device defined in the existing protocol, which will not be repeated here.

[0320] Possibility 7: The host access network device or relay device instructs UE#1 to initiate a registration update to obtain the NS-AoS of the new fourth network slice.

[0321] For ease of understanding, the following describes in detail how to obtain the NS-AoS of the new fourth network slice in the case shown in Possible 7 in conjunction with Figure 10. In the case shown in Possible 7, the method flow shown in Figure 10 includes:

[0322] S1031, the host access network device or the relay device sends fourth indication information to UE#1, and correspondingly, UE#1 receives the fourth indication information from the host access network device or the relay device.

[0323] Specifically, the fourth indication information is used to instruct the first core network device to update the second service area information. For example, the fourth indication information instructs UE#1 to initiate a registration update (such as initiating a registration update through a TAU process) to instruct the first core network device to update the second service area information.

[0324] Optionally, if the fourth indication information is sent by the donor access network device, corresponding to the aforementioned method 1, the relay device (e.g., the access network device portion of the relay device (relay-gNB)) establishes DRB#1. The donor access network device may first indicate the information to the relay device (e.g., the terminal device portion of the relay device (relay-MT)), which then indicates the information to UE#1. Corresponding to the aforementioned method 2, if DRB#2 is established by the donor access network device, the relay device (e.g., the access network device portion of the relay device (relay-gNB)) may transparently transmit the information to UE#1.

[0325] S1032, UE#1 sends the fifth indication information to AMF#1.

[0326] The fifth indication information is used to instruct the first core network device to update the second service area information, where the second service area information is information indicating the service area of ​​the fourth network slice provided by AMF#1. For example, UE#1 initiates a registration update process to AMF#1 through a NAS message.

[0327] Optionally, the host access network device or relay device may carry the identifier of the resident cell of the relay device (eg, the terminal device part (relay-MT) of the relay device) in the NAS message, such as the NCGI of Cell#1.

[0328] Corresponding to the above-mentioned method 1, the relay device (e.g., the access network device part of the relay device (relay-gNB)) establishes DRB#1. The identifier of the resident cell can be directly carried by the relay device (e.g., the terminal device part of the relay device (relay-MT)) in the NAS message of the UE, or the host access network device can carry the identifier of the resident cell through an NGAP message while transparently transmitting the NAS message to the AMF#1 of UE#1. Or,

[0329] Corresponding to the above-mentioned method 2, the donor access network device establishes DRB#2. The identity of the resident cell can be indicated to the donor access network device by the relay device (e.g., the terminal device part (relay-MT) of the relay device) when transparently transmitting the NAS message of UE#1, and then sent by the donor access network device to the AMF#1 of UE#1 through an NGAP message. Alternatively, the donor access network device can directly indicate the identity of the resident cell to the AMF#1 of UE#1 through an NGAP message when transparently transmitting the NAS message of UE#1.

[0330] S1033, AMF#1 updates the second service area information.

[0331] Specifically, based on the identifier of the first cell and the service area of ​​the first network slice, AMF#1 can determine that the first cell is located outside the service area of ​​the first network slice, thereby determining to update the second service area information. The second service area information is the NS-AoS information of the fourth network slice provided by AMF#1. The updated second service area information does not include the identifier of the second cell (i.e., the current resident cell of UE#1). For example, the current resident cell of UE#1 (such as Cell#4) should be removed from the updated second service area information.

[0332] In step S1034, AMF#1 sends the updated second service area information to UE#1. Accordingly, UE#1 receives the updated second service area information from AMF#1. For details, please refer to the description of step S923 in option 6 above, which will not be repeated here.

[0333] S1035, UE#1 determines that the current resident cell is not within the service area of ​​the fourth network slice.

[0334] Specifically, when the terminal device determines that the current resident cell is not within the NS-AoS of the fourth network slice, the subsequent behavior of the terminal device can refer to the behavior description of the terminal device defined in the existing protocol, which will not be repeated here.

[0335] It should be noted that, in the case described in possibility 7, the above steps S510 and S1031 may be optional steps, that is, UE#1 may proactively initiate the update of the second service area information.

[0336] As another implementation method, when the DRB corresponding to the first PDU session associated with the first network slice established by the relay device can no longer be used to carry data on the backhaul link, it is also possible to indicate that the backhaul link for the relevant data of UE#1 has no resources, thereby avoiding the first terminal device from continuing to transmit services based on the second PDU session, which may cause service failure or interruption. The following possibility 8 is this implementation method.

[0337] Possibility 8: The host access network device or relay device indicates to UE#1 that the backhaul link provided by the relay device for UE#1 has no resources.

[0338] For ease of understanding, the following describes in detail the situation shown in Possible 8 in conjunction with FIG11. The method flow shown in FIG11 includes:

[0339] S1141, the host access network device or the relay device sends eighth indication information to UE#1, and correspondingly, UE#1 receives the eighth indication information from the host access network device or the relay device.

[0340] The eighth indication information is used to indicate that the serving cell (e.g., the second cell) provided by the relay device for UE#1 does not belong to the service area of ​​the fourth network slice. For example, the eighth indication information can indicate that the second cell does not belong to the service area of ​​the fourth network slice by indicating that the fourth network slice associated with the DRB for providing the backhaul link for UE#1 by the relay device or the NSAG associated with the fourth network slice has no resources.

[0341] The eighth indication information may be sent via an RRC message or a broadcast message.

[0342] Corresponding to the above-mentioned method 1, the relay device (such as the access network device part of the relay device (relay-gNB)) establishes DRB#1. The eighth indication information can be directly carried by the relay device (such as the terminal device part of the relay device (relay-MT)) in the NAS message of the UE, or the host access network device can carry the identifier of the resident cell through an NGAP message while transparently transmitting the NAS message to the AMF#1 of UE#1. Or,

[0343] Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2. The eighth indication information can be indicated to the host access network device by the relay device (e.g., the terminal device part (relay-MT) of the relay device) when transparently transmitting the NAS message of UE#1, and then sent by the host access network device to the AMF#1 of UE#1 through an NGAP message, or the eighth indication information can be directly indicated to the AMF#1 of UE#1 through an NGAP message by the host access network device when transparently transmitting the NAS message of UE#1.

[0344] S1142, UE#1 determines that the current resident cell is not within the service area of ​​the fourth network slice.

[0345] Specifically, when the terminal device determines that the current resident cell is not within the NS-AoS of the fourth network slice, the subsequent behavior of the terminal device can refer to the behavior description of the terminal device defined in the existing protocol, which will not be repeated here.

[0346] It should be noted that, in the L3 Relay scenario as shown in 8, UE#1 may regard the cell without resources in the backhaul link as outside the NS-AoS of the slice associated with the data transmitted on the backhaul by the UE (even if the resident cell of UE#1 has allocated resources for the slice, such as Cell#4 allocates resources for the fourth network slice, but the DRB providing backhaul for UE#1 has not been allocated resources in the first cell). Alternatively, UE#1 can also remove the resident cell of UE#1 (i.e., Cell#4) from the saved NS-AoS for the fourth network slice (or for the slice associated with the NSAG in the indication information, for the NSAG), then UE#1 determines that the current resident cell is not within the service area of ​​the fourth network slice.

[0347] It should be understood that the size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0348] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0349] It should also be understood that in some of the above embodiments, exemplary descriptions are mainly given using devices in existing network architectures as examples (such as host access network devices, relay devices, first core network devices, second core network devices, or first terminal devices, etc.), and it should be understood that the embodiments of the present application do not limit the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0350] It can be understood that in the above-mentioned method embodiments, the methods and operations implemented by a device (such as a host access network device, a relay device, a first core network device, a second core network device, or a first terminal device) can also be implemented by components of the device (such as a chip or circuit).

[0351] The communication method provided by the embodiments of the present application is described in detail above in conjunction with Figures 5 to 11. The above communication method is mainly introduced from the perspective of the interaction between the various protocol layers of the terminal device. It is understood that in order to implement the above functions, the terminal device includes the corresponding hardware structure and / or software modules for performing each function.

[0352] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware 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 to be beyond the scope of this application.

[0353] The communication device provided in this application is described in detail below with reference to Figures 12 to 14. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for matters not described in detail, reference can be made to the method embodiment above. For the sake of brevity, some contents will not be repeated.

[0354] In the embodiment of the present application, the functional modules of the transmitting device or the receiving device can be divided according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation. The following is an example of dividing each functional module according to each function.

[0355] Figure 12 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can implement corresponding communication functions, and the processing module 12 is used to process data. In other words, the transceiver module 11 is used to perform operations related to receiving and sending, while the processing module 12 is used to perform operations other than receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0356] Optionally, the device 10 may further include a storage module 13, which may be used to store instructions and / or data. The processing module 12 may read the instructions and / or data in the storage module so that the device implements the actions of the devices in the aforementioned method embodiments.

[0357] In one design, the apparatus 10 may correspond to the host access network device or relay device in the above method embodiment, or be a component (such as a chip) of the host access network device or relay device.

[0358] The device 10 can implement the steps or processes executed by the host access network device or relay device in the above method embodiment, wherein the transceiver module 11 can be used to execute the transceiver-related operations of the host access network device or relay device in the above method embodiment, and the processing module 12 can be used to execute the processing-related operations of the host access network device or relay device in the above method embodiment.

[0359] In one possible implementation, the processing module 12 is used to determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with the first protocol data unit PDU session established with the relay device, the data radio bearer DRB corresponding to the first PDU session is used to carry data of the backhaul link, the backhaul link is the backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device. The transceiver module 11 is used to send a first indication message, the first indication message is used to instruct the first core network device to deactivate the second PDU session, and the first core network device serves the first terminal device.

[0360] In another possible implementation, the processing module 12 is used to determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with a first protocol data unit (PDU) session established with the relay device, and the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a backhaul link, which is a backhaul link for transmitting data of a second PDU session of a first terminal device, and the first terminal device is a terminal device accessing the relay device. The processing module 12 is used to determine that the DRB corresponding to a third PDU session is used to carry data of the backhaul link, wherein the third PDU session is associated with a third network slice, and the third network slice has available resources in the first cell.

[0361] In another possible implementation, the processing module 12 is used to determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with a first protocol data unit (PDU) session established with the relay device, the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of the backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session, and the first terminal device is a terminal device accessing the relay device. The transceiver module 11 is used to send fourth indication information, the fourth indication information is used to instruct the first core network device to update the second service area information, the first core network device serves the first terminal device, and the second service area information is information provided by the first core network device indicating the service area of ​​the fourth network slice.

[0362] In another possible implementation, the processing module 12 is used to set the identifier of the resident cell provided by the relay device to the first terminal device as the identifier of the first cell, where the first cell is the resident cell of the relay device and the first terminal device is a terminal device accessing the relay device.

[0363] In which, when the device 10 is used to execute the method in Figure 5, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S502, S504, S506, and S507; the processing module 12 can be used to execute the processing steps in the method, such as steps S503, S505, S508, and S510.

[0364] When the device 10 is used to execute the method in Figure 6, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps; S611, S614, S616; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0365] When the device 10 is used to execute the method in Figure 7, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S721, S724, and S726; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0366] When the device 10 is used to execute the method in Figure 8, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S831 and S833; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0367] When the device 10 is used to execute the method in FIG. 9 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as step S921 ; the processing module 12 may be used to execute the processing steps in the method, such as step S510 .

[0368] When the device 10 is used to execute the method in FIG10 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as step S1031 ; the processing module 12 may be used to execute the processing steps in the method, such as step S510 .

[0369] When the device 10 is used to execute the method in Figure 11, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as step S1141; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0370] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0371] In another design, the apparatus 10 may correspond to the first core network device in the above method embodiment, or a component (such as a chip) of the first core network device.

[0372] The device 10 can implement the steps or processes corresponding to those executed by the first core network device in the above method embodiment, wherein the transceiver module 11 can be used to perform the transceiver-related operations of the first core network device in the above method embodiment, and the processing module 12 can be used to perform the processing-related operations of the first core network device in the above method embodiment.

[0373] In one possible implementation, the transceiver module 11 is configured to receive instruction information for deactivating the second protocol data unit (PDU) session of the first terminal device. The processing module 12 is configured to deactivate the second PDU session, wherein the data radio bearer (DRB) corresponding to the first PDU session established by the relay device is used to carry data of a backhaul link, the backhaul link being a backhaul link for transmitting data of the second PDU session, the first PDU session being associated with a first network slice, and the resident cell of the relay device being located outside the service area of ​​the first network slice.

[0374] In another possible implementation, transceiver module 11 is configured to receive indication information for updating second service area information, where the second service area information is information indicating a service area of ​​a fourth network slice and provided by a first core network device serving a first terminal device. Processing module 12 is configured to update the second service area information in response to the indication information, where the updated second service area information does not include an identifier of a second cell, where the second cell is a resident cell provided by a relay device for the first terminal device. Transceiver module 11 is configured to send the updated second service area information to the first terminal device.

[0375] When the device 10 is used to execute the method in FIG. 5 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S01 , S502 , and S504 ; and the processing module 12 may be used to execute the processing steps in the method.

[0376] When the device 10 is used to execute the method in Figure 5, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S510 and S532; the processing module 12 can be used to execute the processing steps in the method, such as steps S520, S521, S522 and S531.

[0377] When the device 10 is used to execute the method in Figure 6, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S612, S614, and S617; the processing module 12 can be used to execute the processing steps S613, S615, and S618 in the method.

[0378] When the device 10 is used to execute the method in Figure 7, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S722, S724, and S727; the processing module 12 can be used to execute the processing steps S723, S725, and S728 in the method.

[0379] When the device 10 is used to execute the method in FIG. 9 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S921 and S923 ; the processing module 12 may be used to execute the processing step S922 in the method.

[0380] When the device 10 is used to execute the method in FIG10 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S1032 and S1034 ; the processing module 12 may be used to execute the processing step S1033 in the method.

[0381] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0382] In yet another design, the apparatus 10 may correspond to the second core network device in the above method embodiment, or a component (such as a chip) of the second core network device.

[0383] The device 10 can implement the steps or processes corresponding to those executed by the second core network device in the above method embodiment, wherein the transceiver module 11 can be used to execute the transceiver-related operations of the second core network device in the above method embodiment, and the processing module 12 can be used to execute the processing-related operations of the second core network device in the above method embodiment.

[0384] In one possible implementation, the transceiver module 11 is used to receive first indication information, wherein the first indication information includes an identifier of the first core network device, an identifier of the first terminal device, and an identifier of the second protocol data unit PDU session. The transceiver module 11 is used to send sixth indication information in response to the first indication information, wherein the sixth indication information is used to instruct the first core network device to deactivate the second PDU session, wherein the data radio bearer DRB corresponding to the first PDU session established by the relay device is used to carry data of the backhaul link, and the backhaul link is a backhaul link for transmitting data of the second PDU session, the first PDU session is associated with the first network slice, and the resident cell of the relay device is located outside the service area of ​​the first network slice.

[0385] In another possible implementation, the transceiver module 11 is used to receive a third indication information, wherein the third indication information is used to indicate that the first protocol data unit PDU session is deactivated, and the data radio bearer DRB corresponding to the first PDU session is used to carry data of the backhaul link, and the backhaul link is the backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device. The processing module 12 is used to update the network slice associated with the first PDU session from the first network slice to the second network slice in response to the third indication information, wherein the second network slice has available resources in the first cell, the first cell is the resident cell of the relay device, and the first cell is located outside the service area of ​​the first network slice; and send a first message, wherein the first message is used to indicate the second network slice associated with the first PDU session.

[0386] When the device 10 is used to execute the method in FIG. 5 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S506 and S507 ; and the processing module 12 may be used to execute the processing steps in the method.

[0387] When the device 10 is used to execute the method in FIG6 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S611 and S612 ; the processing module 12 may be used to execute the processing steps in the method.

[0388] When the device 10 is used to execute the method in FIG. 7 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S721 and S722 ; the processing module 12 may be used to execute the processing steps in the method.

[0389] When the device 10 is used to execute the method in Figure 8, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S831 and S833; the processing module 12 can be used to execute the processing steps in the method, such as step S832.

[0390] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0391] In yet another design, the apparatus 10 may correspond to the second core network device in the above method embodiment, or a component (such as a chip) of the second core network device.

[0392] The device 10 can implement the steps or processes corresponding to those executed by the first terminal device in the above method embodiment, wherein the transceiver module 11 can be used to execute the transceiver-related operations of the first terminal device in the above method embodiment, and the processing module 12 can be used to execute the processing-related operations of the first terminal device in the above method embodiment.

[0393] In one possible implementation, the transceiver module 11 is used to receive first indication information, wherein the first indication information includes an identifier of the second protocol data unit PDU session. The transceiver module 11 is used to send seventh indication information to the first core network device in response to the first indication information, wherein the seventh indication information includes an identifier of the second PDU session, and the seventh indication information is used to indicate deactivation of the second PDU session, wherein the data radio bearer DRB corresponding to the first PDU session established by the relay device is used to carry data of the backhaul link, and the backhaul link is the backhaul link for transmitting data of the second PDU session, the first PDU session is associated with the first network slice, and the resident cell of the relay device is outside the service area of ​​the first network slice.

[0394] In another possible implementation, the transceiver module 11 is configured to send fifth indication information, where the fifth indication information is used to instruct the first core network device to update second service area information, where the second service area information is information indicating a service area of ​​a fourth network slice and provided by the first core network device, where the first core network device is a core network device serving the first terminal device. The transceiver module 11 is configured to receive updated second service area information, where the updated second service area information does not include an identifier of a second cell, where the second cell is a resident cell provided by the relay device for the first terminal device.

[0395] In another possible implementation, the transceiver module 11 is configured to receive eighth indication information, where the eighth indication information is used to indicate that the second cell does not belong to the service area of ​​the fourth network slice. The processing module 12 is configured to determine, in response to the eighth indication information, that the second cell is not regarded as a cell within the service area of ​​the fourth network slice, or the processing module 12 is configured to remove the second cell from the service area of ​​the fourth network slice in response to the eighth indication information, wherein the second cell is a resident cell provided by a relay device, the service area of ​​the fourth network slice is at least one cell indicated by the second service area information provided by the first core network device serving the first terminal device, the at least one cell includes the second cell, and the first terminal device is a terminal device accessing the relay device.

[0396] When the device 10 is used to execute the method in FIG. 5 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as step S501 ; and the processing module 12 may be used to execute the processing steps in the method.

[0397] When the device 10 is used to execute the method in FIG6 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S616 and S617 ; and the processing module 12 may be used to execute the processing steps in the method.

[0398] When the device 10 is used to execute the method in FIG. 7 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as steps S726 and S727 ; the processing module 12 may be used to execute the processing steps in the method.

[0399] When the device 10 is used to execute the method in FIG. 9 , the transceiver module 11 may be used to execute the steps of sending and receiving information in the method, such as step S923 ; the processing module 12 may be used to execute the processing steps in the method, such as step S924 .

[0400] When the device 10 is used to execute the method in Figure 10, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S1031, S1032, and S1034; the processing module 12 can be used to execute the processing steps in the method, such as step S1035.

[0401] When the device 10 is used to execute the method in Figure 11, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as step S1141; the processing module 12 can be used to execute the processing steps in the method, such as step S1142.

[0402] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0403] It should also be understood that the device 10 here is embodied in the form of a functional module. The term "module" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 10 may be specifically the mobile management network element in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the mobile management network element in the above-mentioned method embodiments; or, the device 10 may be specifically the terminal device in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the terminal device in the above-mentioned method embodiments. To avoid repetition, it will not be described here.

[0404] The device 10 of each of the above-mentioned schemes has the function of implementing the corresponding steps performed by the device (such as the host access network device, the relay device, the first core network device, the second core network device, or the first terminal device) in the above-mentioned method. This function can be implemented by hardware, or it can be implemented by hardware executing the corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions; for example, the transceiver module can be replaced by a transceiver (for example, the sending unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as the processing module, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0405] In addition, the transceiver module 11 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing module may be a processing circuit.

[0406] Figure 13 is a schematic diagram of another communication device 20 provided in an embodiment of the present application. Device 20 includes a processor 21, which is configured to execute computer programs or instructions stored in memory 22, or read data / signaling stored in memory 22, to perform the methods described in the above method embodiments. Optionally, there may be one or more processors 21.

[0407] Optionally, as shown in FIG13 , the device 20 further includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be separately provided. Optionally, there may be one or more memories 22.

[0408] Optionally, as shown in Figure 13, the device 20 further includes a transceiver 23, which is used to receive and / or send signals. For example, the processor 21 is used to control the transceiver 23 to receive and / or send signals.

[0409] As a solution, the apparatus 20 is used to implement the operations performed by the host access network device in each of the above method embodiments.

[0410] As another solution, the apparatus 20 is used to implement the operations performed by the relay device in each of the above method embodiments.

[0411] As another solution, the apparatus 20 is configured to implement the operations performed by the first core network device in each of the above method embodiments.

[0412] As another solution, the apparatus 20 is configured to implement the operations performed by the second core network device in each of the above method embodiments.

[0413] As another solution, the apparatus 20 is used to implement the operations performed by the first terminal device in the above method embodiments.

[0414] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0415] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0416] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0417] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0418] 14 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0419] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 30 can implement the methods and functions of the various embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, outputting information processed by the chip system 30 or inputting data or signaling information to be processed into the chip system 30 for processing.

[0420] As a solution, the chip system 30 is used to implement the operations performed by the host access network device, the relay device, the first core network device, the second core network device, or the first terminal device in the above various method embodiments.

[0421] For example, the logic circuit 31 is used to implement the processing-related operations performed by the host access network device, the relay device, the first core network device, the second core network device, or the first terminal device in the above method embodiments; the input / output interface 32 is used to implement the sending and / or receiving-related operations performed by the host access network device, the relay device, the first core network device, the second core network device, or the first terminal device in the above method embodiments.

[0422] An embodiment of the present application also provides a computer-readable storage medium on which computer instructions are stored for implementing the methods executed by the host access network device, relay device, first core network device, second core network device, or first terminal device in the above-mentioned method embodiments.

[0423] For example, when the computer program is executed by a computer, the computer can implement the methods performed by the host access network device, relay device, first core network device, second core network device, or first terminal device in each embodiment of the above method.

[0424] An embodiment of the present application also provides a computer program product comprising instructions, which, when executed by a computer, implement the methods performed by the host access network device, the relay device, the first core network device, the second core network device, or the first terminal device in the above-mentioned method embodiments.

[0425] The embodiment of the present application further provides a communication system, comprising the aforementioned host access network device, a relay device, a first core network device, and a second core network device. Optionally, the communication system further comprises the aforementioned first terminal device.

[0426] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0427] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. 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. In addition, 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.

[0428] 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.

[0429] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0430] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the 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.

[0431] 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.

[0432] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0433] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0434] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: Determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with a first protocol data unit PDU session established with the relay device, the data radio bearer DRB corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device; Send a first indication message, where the first indication message is used to instruct the first core network device to deactivate the second PDU session, and the first core network device serves the first terminal device.

2. The method according to claim 1, characterized in that The determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, Determine, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, wherein the first service area information is information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or It is determined that the first PDU session is deactivated.

3. The method according to claim 1 or 2, characterized in that: The sending of the first indication information includes: sending the first indication information to the second core network device, where the first indication information includes an identifier of the first core network device, an identifier of the first terminal device, and an identifier of the second PDU session, and the first indication information is used to instruct the second core network device to instruct the first core network device to deactivate the second PDU session, Wherein, the second core network device serves the relay device.

4. The method according to claim 1 or 2, characterized in that: The sending of the first indication information includes: The first indication information is sent to the first core network device, wherein the first indication information includes an identifier of the first terminal device and an identifier of the second PDU session.

5. The method according to claim 1 or 2, characterized in that: The sending of the first indication information includes: The first indication information is sent to the first terminal device, wherein the first indication information includes an identifier of the second PDU session, and the first indication information is used to instruct the first terminal device to initiate deactivation of the second PDU session to the first core network device.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: Release the resources configured for the second PDU session.

7. The method according to claim 6, characterized in that Before releasing the resources configured for the second PDU session, the method further includes: Receive second indication information, where the second indication information is used to indicate the release of resources configured for the second PDU session.

8. A communication method, characterized in that: include: Receiving instruction information for deactivating a second protocol data unit (PDU) session of the first terminal device; deactivating the second PDU session, Among them, the data radio bearer DRB corresponding to the first PDU session established by the relay device is used to carry data of the backhaul link, and the backhaul link is a backhaul link for transmitting data of the second PDU session. The first PDU session is associated with the first network slice, and the resident cell of the relay device is located outside the service area of ​​the first network slice.

9. The method according to claim 8, characterized in that The receiving instruction information for deactivating the second PDU session of the first terminal device includes: Receiving the indication information from at least one of the following devices: the relay device, the host access network device, the second core network device, or the first terminal device, Among them, the second core network device serves the relay device, and the indication information includes the identifier of the first terminal device and the identifier of the second PDU session.

10. The method according to claim 8 or 9, characterized in that: The method further comprises: Send second indication information, where the second indication information is used to indicate the release of resources configured for the second PDU session.

11. A communication method, characterized in that: include: receiving third indication information, wherein the third indication information is used to instruct to deactivate a first protocol data unit PDU session, wherein the first The data radio bearer DRB corresponding to the PDU session is used to carry data of the backhaul link, and the backhaul link is the backhaul link of the second PDU session transmission data of the first terminal device, and the first terminal device is a terminal device accessing the relay device In response to the third indication information, the network slice associated with the first PDU session is updated from the first network slice to the second network slice, where the second network slice has available resources in the first cell, the first cell is a resident cell of the relay device, and the first cell is located outside the service area of ​​the first network slice; Send a first message, where the first message is used to indicate the second network slice associated with the first PDU session.

12. A communication method, characterized in that: include: Determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with a first protocol data unit PDU session established with the relay device, the data radio bearer DRB corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device; Determine that the DRB corresponding to the third PDU session is used to carry the data of the backhaul link, The third PDU session is associated with a third network slice, and the third network slice has available resources in the first cell.

13. The method according to claim 12, characterized in that The determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, Determine, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, wherein the first service area information is information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or It is determined that the first PDU session is deactivated.

14. A communication method, characterized in that: include: Receive indication information for updating second service area information, where the second service area information is information indicating a service area of ​​a fourth network slice provided by a first core network device serving a first terminal device; In response to the indication information, the second service area information is updated, where the updated second service area information does not include an identifier of a second cell, where the second cell is a resident cell provided by the relay device for the first terminal device; Send the updated second service area information to the first terminal device.

15. The method according to claim 14, characterized in that The receiving instruction information for updating the second service area information includes: Receiving the indication information from at least one of the following devices: The relay device, the host access network device, or the first terminal device.

16. A communication method, characterized in that: include: Determine that the first cell is located outside the service area of ​​the first network slice, the first cell is a resident cell of the relay device, the first network slice is associated with a first protocol data unit PDU session established with the relay device, the data radio bearer DRB corresponding to the first PDU session is used to carry data of a backhaul link, the backhaul link is a backhaul link for transmitting data of the second PDU session of the first terminal device, and the first terminal device is a terminal device accessing the relay device; Send fourth indication information, where the fourth indication information is used to instruct the first core network device to update second service area information, where the first core network device serves the first terminal device, and the second service area information is information indicating the service area of ​​the fourth network slice provided by the first core network device.

17. The method according to claim 16, characterized in that The determining that the first cell is located outside the service area of ​​the first network slice includes: determining that the first cell does not include resources allocated to the first network slice; or, Determine, based on the identifier of the first cell and the identifier of at least one cell included in the first service area information, that the identifier of the first cell does not belong to any of the identifiers of the at least one cell, wherein the first service area information is information indicating the service area of ​​the first network slice provided by the second core network device serving the relay device; or It is determined that the first PDU session is deactivated.

18. The method according to claim 16 or 17, characterized in that The sending of the fourth indication information includes: Send the fourth indication information to the first core network device and / or the first terminal device.

19. A communication method, characterized in that: include: Sending fifth indication information, where the fifth indication information is used to instruct the first core network device to update second service area information, where the second service area information is information indicating a service area of ​​a fourth network slice provided by the first core network device, and the first core network device is a core network device serving the first terminal device; The updated second service area information is received, where the updated second service area information does not include an identifier of a second cell, where the second cell is a resident cell provided by the relay device for the first terminal device.

20. The method according to claim 19, characterized in that Before sending the fifth indication information, the method further includes: Receive fourth indication information from the relay device and / or the host access network device, where the fourth indication information is used to instruct the first core network device to update the second service area information.

21. A communication device, characterized in that: The communication device comprises a processor and a memory, wherein the processor and the memory are coupled, and the memory is used to store a computer program. When the processor runs the computer program, the communication device executes the method according to any one of claims 1 to 20.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a communication device, the communication device is caused to execute the method according to any one of claims 1 to 20.

23. A computer program product, characterized in that The method comprises computer instructions, which, when executed on a communication device, cause the communication device to execute the method according to any one of claims 1 to 20.

24. A chip, characterized in that: The chip includes a processor and a communication interface. The processor reads instructions and runs through the communication interface. When the chip is installed in a communication device, the communication device executes the method as described in any one of claims 1-20.

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