Communication method and communication device

Abstract

Provided is a communication method, comprising: a host access network device or a relay device determining that a resident cell of the relay device is located outside a service area of a first network slice, the first network slice being associated with a first PDU session established by the relay device, a DRB corresponding to the first PDU session being used for bearing data of a return link, the backhaul link is a backhaul link of the second PDU session transmission data of the first terminal device accessing the relay device. And the host access network device or the relay device instructs the first core network device serving the first terminal device to deactivate the second PDU session through the first indication information. The service failure or interruption caused by the fact that the first terminal device continues to carry out service transmission based on the second PDU session can be avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technologies, and more particularly, to a communication method and a communication device. Background Art

[0002] With the development of mobile communication technologies, various new services and application scenarios have emerged continuously. The requirements of these services for network functions, connection performance, security, etc. vary greatly. If a single network is used to carry these services, it will be difficult to meet the requirements such as high bandwidth, low latency, and high reliability at the same time. In addition, building a separate network for each service will incur huge costs. This requires that the fifth-generation (5G) communication system be flexible and scalable while meeting different service requirements. For this purpose, the 5G communication system provides customized network services for users through end-to-end network slicing.

[0003] In addition, a layer 3 (L3) relay system includes relay devices, and the relay devices include relay terminal devices and relay network devices. Among them, the data plane or user plane data of a first terminal device accessing the relay network device is backhauled through a data radio bearer (DRB) established between the relay terminal device and a host base station.

[0004] 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 backhaul link data does not include the resident cell of the relay device, the protocol data unit (PDU) session request for establishing the network slice association initiated by the relay device in the resident cell 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 for 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 fail to request services or the established services to be interrupted. Summary of the Invention

[0005] The present application provides a communication method to avoid the failure of a terminal device to request services or the interruption of established services.

[0006] In a first aspect, a communication method is provided. This method can be executed by a host access network device or a relay device, or by components (such as chips or circuits or chip systems) of a host access network device or a relay device. The present application does not limit this.

[0007] The communication method includes: determining that a first cell is outside the service area of a first network slice, where the first cell is the resident cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established by the relay device, a 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 first indication information for instructing a first core network device to deactivate the second PDU session, where the first core network device serves the first terminal device.

[0008] Based on the above technical solution, taking the execution by a host access network device or a relay device as an example, the host access network device or the relay device may determine that the current resident cell of the relay device 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 cannot continue to be used to carry data of the backhaul link, and the backhaul link is a backhaul link for transmitting data of the second PDU session. Therefore, the host access network device or the relay device may, through the first indication information, instruct the first core network device serving the first terminal device to deactivate the second PDU session, so as to avoid the first terminal device from continuing to perform service transmission based on the second PDU session, resulting in service failure or interruption.

[0009] In combination with the first aspect, in some implementation manners of the first aspect, the determining that the first cell is outside the service area of the first network slice includes: determining that the first cell does not include resources allocated for the first network slice; or, determining, according to the identifier of the first cell and the identifiers 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 a second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0010] Based on the above technical solutions, the first cell can be determined to be outside the service area of the first network slice in different ways, improving the flexibility of the solution. For example, if the device that determines that the first cell is outside the service area of the first network slice is the host access network device, 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 outside the service area of the first network slice; also for example, if the device that determines that the first cell is outside the service area of the first network slice is the relay device, 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 according to the identifier of the first cell and the first service area information of the first network slice, where the first service area information includes the identifiers of at least one cell included in the service area of the first network slice; and for another example, if the device that determines that the first cell is outside the service area of the first network slice is the relay device, when the relay device senses that the first PDU session is deactivated, it is considered that the first cell is outside the service area of the first network slice.

[0011] Combined with the first aspect, in some implementation manners of the first aspect, the sending of the first indication information includes: sending the first indication information to a second core network device, where the first indication information includes the identifier of the first core network device, the identifier of the first terminal device, and the 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, where the second core network device serves the relay device.

[0012] Combined with the first aspect, in some implementation manners of the first aspect, the sending of the first indication information includes: sending the first indication information to the first core network device, where the first indication information includes the identifier of the first terminal device and the identifier of the second PDU session.

[0013] Combined with the first aspect, in some implementation manners of the first aspect, the sending of the first indication information includes: sending the first indication information to the first terminal device, where the first indication information includes 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.

[0014] Based on the above technical solution, the first indication information sent by the host access network device or the relay device may be: the host access network device or the 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, it may directly send the first indication information to the first core network device; or, it may send the first indication information 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, improving the flexibility of the solution.

[0015] Combined with the first aspect, in some implementation manners of the first aspect, the method further includes: releasing the resources configured for the second PDU session.

[0016] Combined with the first aspect, in some implementation manners 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 releasing the resources configured for the second PDU session.

[0017] In a second aspect, a communication method is provided. This method may be executed by the first core network device or by components (such as chips or circuits or chip systems) of the first core network device. This application does not make any limitations in this regard. For example, the first core network device is a core network device serving the first terminal device. For example, the first core network device is an AMF that manages the first terminal device.

[0018] 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, where 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 a first network slice, and the cell where the relay device resides is outside the service area of the first network slice.

[0019] Based on the above technical solution, after the core network device serving the first terminal device receives the indication information instructing to deactivate the second PDU session, it executes the process of deactivating the second PDU in response to the indication information, so as to avoid the situation where the first terminal device continues to perform service transmission based on the second PDU session when 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 of the backhaul link (the backhaul link is the backhaul link for transmitting data of the second PDU session), resulting in service failure or interruption.

[0020] In combination with the second aspect, in some implementations of the second aspect, the receiving of the 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, where 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.

[0021] Based on the above technical solution, the first core network device can receive the indication information for deactivating the second protocol data unit (PDU) session of the first terminal device from any one or more of the relay device, the host access network device, the second core network device, or the first terminal device, improving the flexibility of the solution.

[0022] In combination with the second aspect, in some implementations of the second aspect, the method further includes: sending second indication information for indicating the release of the resources configured for the second PDU session.

[0023] In a third aspect, a communication method is provided. This method can be executed by the second core network device or by components (such as chips or circuits or chip systems) of the second core network device. This application does not limit this. For example, the second core network device is a core network device serving the relay device. For example, the second core network device is an AMF that manages the relay device.

[0024] This communication method includes: receiving first indication information that includes the identifier of the first core network device, the identifier of the first terminal device, and the identifier of the second protocol data unit (PDU) session; in response to the first indication information, sending sixth indication information for indicating the first core network device to deactivate the second PDU session, where the data radio bearer (DRB) corresponding to the first PDU session established by the relay device 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 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.

[0025] Based on the above technical solution, after receiving the indication information for 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 for deactivating the second PDU session to the first core network device in response to the indication information, so as to avoid 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 the data of 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 perform service transmission based on the second PDU session, resulting in service failure or interruption.

[0026] In combination with the third aspect, in some implementation manners of the third aspect, the receiving the first indication information includes: receiving the first indication information from the relay device and / or the host access network device.

[0027] In combination with the third aspect, in some implementation manners of the third aspect, the method further includes: deactivating the first PDU session.

[0028] In a fourth aspect, a communication method is provided. This method can be executed by the first terminal device or by a component (such as a chip or a circuit or a chip system) of the first terminal device. This application does not limit this.

[0029] The communication method includes: receiving first indication information, where 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, where the seventh indication information includes the identifier of the second PDU session, and the seventh indication information is used to instruct deactivation of the second PDU session, where a data radio bearer (DRB) corresponding to a first PDU session established by a relay device is used to carry data of a backhaul link, the backhaul link is the backhaul link for transmitting data of the second PDU session, the first PDU session is associated with a first network slice, and a resident cell of the relay device is outside a service area of the first network slice.

[0030] Based on the above technical solution, after receiving the indication information for instructing the first core network device to deactivate the second PDU session, the first terminal device sends the seventh indication information for deactivating the second PDU session to the first core network device in response to the indication information, so as to avoid 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 the data of 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 perform service transmission based on the second PDU session, resulting in service failure or interruption.

[0031] In combination with the fourth aspect, in some implementations of the fourth aspect, the receiving the first indication information includes: receiving the first indication information from the relay device and / or the host access network device.

[0032] Fifth aspect, a communication method is provided. This method can be executed by the second core network device or by components (such as chips or circuits or chip systems) of the second core network device. This application does not make any limitations in this regard. For example, the second core network device is a core network device serving the relay device. For example, the second core network device is an AMF that manages the relay device.

[0033] The communication method includes: receiving third indication information for indicating deactivating a first protocol data unit (PDU) session, where 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 the second PDU session of the first terminal device to transmit data, and the first terminal device is a terminal device accessing the relay device; in response to the third indication information, updating the network slice associated with the first PDU session from a first network slice to a second network slice, where there are available resources in the first cell for the second network slice, the first cell is the cell where the relay device is resident, and the first cell is outside the service area of the first network slice; sending a first message for indicating the second network slice associated with the first PDU session.

[0034] Based on the above technical solution, in a scenario where the 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 for indicating deactivating the first PDU session, it is determined that there are no configured resources for the first network slice associated with the first PDU session in the first cell. Therefore, 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 there are available resources for the second network slice 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 perform service transmission based on the second PDU session.

[0035] Sixth aspect, a communication method is provided. This method can be executed by the host access network device or the relay device, or by components (such as chips or circuits or chip systems) of the host access network device or the relay device. This application does not make any limitations in this regard.

[0036] The communication method includes: determining that a first cell is outside the service area of a first network slice, where the first cell is the serving cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established by the relay device, a 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; where the third PDU session is associated with a third network slice, and there are available resources in the first cell for the third network slice.

[0037] Based on the above technical solution, taking the execution by a host access network device or a relay device as an example, the host access network device or the relay device may determine that the current serving cell of the relay device 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 of the backhaul link, and the backhaul link is a backhaul link for transmitting data of a second PDU session. Therefore, the host access network device or the relay device may select a DRB corresponding to a third PDU session associated with a third network slice configured with resources in the first cell to carry data of the backhaul link, so that the first terminal device can continue to perform service transmission based on the second PDU session.

[0038] Combined with the sixth aspect, in some implementation manners of the sixth aspect, the determining that the first cell is outside the service area of the first network slice includes: determining that the first cell does not include resources allocated for the first network slice; or, determining, according to the identifier of the first cell and the identifiers 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 a second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0039] In a seventh aspect, a communication method is provided. This method may be executed by a relay device or by components (such as a chip, a circuit, or a chip system) of the relay device. This application does not make any limitations in this regard.

[0040] The communication method includes: the relay device sets the identifier of the serving cell provided by the relay device for a first terminal device to the identifier of a first cell, where the first cell is the serving cell of the relay device, and the first terminal device is a terminal device accessing the relay device.

[0041] Based on the above technical solution, the serving 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 serving cell provided by the relay device consistent with the identifier of the serving cell where the relay device is currently located. It can be understood that the serving cell of the terminal device accessing the relay device is regarded as an extension of the serving cell of the relay device. If the serving cell where the relay device is currently located is not within the service area of a certain network slice, the terminal device accessing this relay device can also learn that the serving cell where it is currently located is not within the service area of a certain network slice.

[0042] Combined with the seventh aspect, in some implementation manners of the seventh aspect, before the relay device sets the identifier of the serving cell provided by the relay device to the identifier of the first cell, the method further includes: the relay device determines that the first cell is 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, the data radio bearer (DRB) corresponding to the first PDU session is used as the backhaul link for transmitting data of 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.

[0043] In an eighth aspect, a communication method is provided. This method can be executed by the first core network device, or by a component (such as a chip, a circuit, or a chip system) of the first core network device. This application does not limit this. For example, the first core network device is the core network device serving the first terminal device. For example, the first core network device is the access and mobility management function (AMF) that manages the first terminal device.

[0044] This communication method includes: receiving an indication message for updating the second service area information, where the second service area information is the information indicating the service area of the fourth network slice provided by the first core network device serving the first terminal device; in response to the indication message, updating the second service area information, and the updated second service area information does not include the identifier of the second cell, where the second cell is the serving cell provided by the relay device for the first terminal device; and sending the updated second service area information to the first terminal device.

[0045] Based on the above technical solution, after receiving the indication information for updating 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. Thus, 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 serving 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 service failure or interruption caused by the first terminal device continuing to perform service transmission based on the second PDU session.

[0046] Combined with the eighth aspect, in some implementation manners of the eighth aspect, the receiving the 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.

[0047] Based on the above technical solution, the first core network device can receive the indication information for indicating the update of the second service area information from any one or more of the relay device, the host access network device, or the first terminal device, improving the flexibility of the solution.

[0048] The ninth aspect provides a communication method. This method can be executed by the host access network device or the relay device, or can be executed by components (such as chips or circuits or chip systems) of the host access network device or the relay device. This application does not make any limitations in this regard.

[0049] This communication method includes: determining that the first cell is outside the service area of the first network slice, where the first cell is the serving cell of the relay device, the first network slice is associated with the first protocol data unit PDU session established by the relay device, the data radio bearer DRB corresponding to the first PDU session 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, and the first terminal device is the terminal device accessing the relay device; sending the fourth indication information, where the fourth indication information is used to indicate 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 the information provided by the first core network device indicating the service area of the fourth network slice.

[0050] In combination with the ninth aspect, in some implementations of the ninth aspect, determining that the first cell is outside the service area of the first network slice includes: determining that the first cell does not include resources allocated for the first network slice; or, determining that the identifier of the first cell does not belong to any of the identifiers of the at least one cell according to the identifier of the first cell and the identifiers of the at least one cell included in the first service area information, where the first service area information is information indicating the service area of the first network slice provided by a second core network device serving the relay device; or, determining that the first PDU session is deactivated.

[0051] In combination with the ninth aspect, in some implementations of the ninth aspect, sending the fourth indication information includes: sending the fourth indication information to the first core network device and / or the first terminal device.

[0052] The tenth aspect provides a communication method. This method can be executed by a first terminal device or by a component (such as a chip, circuit, or chip system) of the first terminal device. This application does not make any limitations in this regard.

[0053] This communication method includes: sending a fifth indication information for indicating a first core network device to update second service area information, where the second service area information is information indicating the 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; receiving the updated second service area information, and the updated second service area information does not include the identifier of a second cell, where the second cell is a cell in which the relay device provides residence for the first terminal device.

[0054] In combination with the tenth aspect, in some implementations of the tenth aspect, before sending the fifth indication information, the method further includes: receiving fourth indication information from the relay device and / or the host access network device, where the fourth indication information is used to indicate the first core network device to update the second service area information.

[0055] The eleventh aspect provides a communication method. This method can be executed by a first terminal device or by a component (such as a chip, circuit, or chip system) of the first terminal device. This application does not make any limitations in this regard.

[0056] The communication method includes: a first terminal device receiving eighth indication information, where the eighth indication information is used to indicate that a second cell does not belong to a service area of a fourth network slice; the first terminal device determining, 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 removing the second cell from the service area of the fourth network slice in response to the eighth indication information, where 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 second service area information provided by a 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.

[0057] In a twelfth aspect, a communication device is provided. The communication device may be a first device, or may be a module or unit (for example, a chip, or a chip system, or a circuit) corresponding one by one to the methods / operations / steps / actions described in the first aspect to the eleventh aspect and any one of their implementation manners in the first device, or may be capable of being used in matching with the first device.

[0058] Exemplarily, the first device may be the host access network device or the relay device in the first aspect, the sixth aspect or the ninth aspect above, or a component (for example, a chip or a circuit or a chip system) of the host access network device or the relay device. The first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the first aspect, the sixth aspect or the ninth aspect and any one of their implementation manners, and includes a processing module or unit for performing the processing operations / steps / actions described in the first aspect, the sixth aspect or the ninth aspect and any one of their implementation manners.

[0059] Exemplarily, the first device may be the first core network device in the second aspect, the eighth aspect or a component (for example, a chip or a circuit or a chip system) of the first core network device. 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 implementation manners, and includes 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 implementation manners.

[0060] Exemplarily, the first device may be the second core network device in the third aspect and the fifth aspect above, or a component of the second core network device (such as a chip, a circuit, or a chip system). 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 of their implementation manners, and a processing module or unit for performing the processing operations / steps / actions described in the third aspect, the fifth aspect, and any of their implementation manners.

[0061] Exemplarily, the first device may be the first terminal device in the fourth aspect, the tenth aspect, or the eleventh aspect above, or a component of the first terminal device (such as a chip, a circuit, or a chip system). 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 of their implementation manners, 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 of their implementation manners.

[0062] Exemplarily, the first device may be the relay device in the seventh aspect above, or a component of the relay device (such as a chip, a circuit, or a chip system). The first device includes a transceiver module or unit for performing the transceiver operations / steps / actions described in the seventh aspect and any of its implementation manners, and a processing module or unit for performing the processing operations / steps / actions described in the seventh aspect and any of its implementation manners.

[0063] In a thirteenth aspect, a communication device is provided. The communication device is used to perform the methods provided in the first aspect to the eleventh aspect and any of their implementation manners above. Specifically, the communication device may include units and / or modules (such as a processing unit, a transceiver unit) for performing the methods provided in the first aspect to the eleventh aspect and any of their implementation manners.

[0064] In one implementation manner, 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. Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0065] In another implementation manner, the communication device may be a chip, a chip system, or a circuit in a device. At this time, the transceiver unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or a related circuit, etc. on the chip, the chip system, or the circuit; the processing unit may be at least one processor, a processing circuit, or a logic circuit, etc.

[0066] In a fourteenth aspect, the present application provides a processor for executing the methods provided in the first to eleventh aspects above.

[0067] For operations such as sending and obtaining / receiving involved in the processor, if there is no special description, or if it does not conflict with its actual role or internal logic in the relevant description, it can be understood as operations such as outputting and receiving, inputting by the processor, or it can also be understood as sending and receiving operations performed by the radio frequency circuit and the antenna. The present application does not make any limitations in this regard.

[0068] In a fifteenth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, and when the computer program runs on a communication device, the communication device is caused to execute the method according to any one of the implementations of the first to eleventh aspects above.

[0069] In a sixteenth aspect, a computer program product containing instructions is provided. When the computer program product runs on a computer, the computer is caused to execute the method provided in any one of the implementations of the first to eleventh aspects above.

[0070] In a seventeenth aspect, a chip is provided. The chip includes a processor and a communication interface. The processor reads instructions through the communication interface and executes the method provided in any one of the implementations of the first to eleventh aspects above.

[0071] Optionally, as an implementation, the chip further includes a memory that stores a computer program or instructions. The processor is configured to execute the computer program or instructions stored on the memory. When the computer program or instructions are executed, the processor is configured to execute the method provided in any one of the implementations of the first to sixth aspects above.

[0072] In an eighteenth aspect, a communication system is provided, including a host access network device or a relay device that executes the method according to any one of the implementations of the first aspect, a first core network device that executes the method according to any one of the implementations of the second aspect, a second core network device that executes the method according to any one of the implementations of the third aspect, and a first terminal device that executes the method according to any one of the implementations of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 is a schematic diagram of a communication system 100 to which the embodiments of the present application are applicable.

[0074] Figure 2 is a schematic diagram of a network slice service area provided by the present application.

[0075] Figure 3 is a schematic diagram of a relay architecture provided by the present application.

[0076] Figure 4 It is a schematic diagram of data transmission in an L3 Relay system provided by this application.

[0077] Figure 5 It is a schematic flowchart of a communication method provided by this application.

[0078] Figure 6 It is a schematic flowchart of another communication method provided by this application.

[0079] Figure 7 It is a schematic flowchart of yet another communication method provided by this application.

[0080] Figure 8 It is a schematic flowchart of yet another communication method provided by this application.

[0081] Figure 9 It is a schematic flowchart of yet another communication method provided by this application.

[0082] Figure 10 It is a schematic flowchart of yet another communication method provided by this application.

[0083] Figure 11 It is a schematic flowchart of yet another communication method provided by this application.

[0084] Figure 12 It is a schematic block diagram of a communication device 10 provided by an embodiment of this application.

[0085] Figure 13 It is a schematic diagram of another communication device 20 provided by an embodiment of this application.

[0086] Figure 14 It is a schematic diagram of a chip system 30 provided by an embodiment of this application. Detailed implementation manners

[0087] For the convenience of understanding the embodiments of this application, the following points are explained.

[0088] First, in this application, "for indicating" may include for direct indication and for indirect indication. When describing that a certain indication information is used to indicate A, it may include that the indication information directly indicates A or indirectly indicates A, and does not mean that A must be included in the indication information.

[0089] The information indicated by the indication information is referred to as the information to be indicated. In 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 can be divided into multiple sub-information and sent separately. Moreover, the sending periods and / or sending timings of these sub-information can be the same or different. The specific sending method is not limited in this application. Among them, the sending periods and / or sending timings of these sub-information can be predefined, for example, predefined according to a protocol, or can be configured by the transmitting device by sending configuration information to the receiving device.

[0090] Second, "at least one" shown in this application means one or more, and "multiple" means two or more. In addition, in the embodiments of this application, "first", "second" and various numerical 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 this application. The size of the serial numbers of the following processes does not mean the sequence of execution. The execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application. It should be understood that the objects described in this way can be interchanged under appropriate circumstances so as to be able to describe the solutions other than the embodiments of this application. In addition, in the embodiments of this application, words such as "S501" and "S502" are only identifiers made for the convenience of description and do not limit the order of execution steps.

[0091] Third, in this application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplary" or "for example" aims to present relevant concepts in a specific way.

[0092] Fourth, the "storage" involved in the embodiments of this application can refer to being stored in one or more memories. The one or more memories can be set separately, or can be integrated in an encoder or decoder, a processor, or a communication device. The one or more memories can also be partially set separately and partially integrated in a decoder, a processor, or a communication device. The type of the memory can be any form of storage medium, and this application does not limit this.

[0093] Fifth, the "protocol" involved in the embodiments of this application can refer to the standard protocols in the communication field. For example, it can include LTE protocols, NR protocols, and related protocols applied to future communication systems. This application does not limit this.

[0094] Sixth, in the embodiments of the present application, the expressions "in... case", "when...", and "if..." can sometimes be used interchangeably. It should be noted that when not emphasizing their differences, they convey the same meaning.

[0095] Seventh, in the embodiments of the present application, the terms and English abbreviations, such as radio resource control (RRC), etc., are all exemplary examples given for convenience of description and should not constitute any limitation to the present application. The present application does not exclude the possibility of defining other terms in existing or future protocols that can achieve the same or similar functions.

[0096] Eighth, the term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the front and rear associated objects.

[0097] Next, the technical solutions in the present application will be described with reference to the accompanying drawings.

[0098] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: the 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 by 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 systems or other communication systems.

[0099] To facilitate the understanding of the embodiments of the present application, first, Figure 1 the communication system shown in Figure 1 is taken as an example to detail the communication system applicable to the embodiments of the present application. Figure 1 As shown, the communication system 100 may include at least one access network device, such asFigure 1 The access network device 110 shown; the communication system 100 may further include at least one terminal device, such as Figure 1 the terminal device 120 shown; the communication system 100 may further include at least one core network (CN) device, such as Figure 1 the core network device 130 shown. 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 multiple antennas configured may include at least one transmit antenna for transmitting signals and at least one receive antenna for receiving signals. Therefore, between the communication devices in the communication system 100, such as between the access network device 110 and the terminal device 120, communication may be performed via multi-antenna technology.

[0100] By way of example and not limitation, for Figure 1 the access network device and the terminal device in the scenario shown, communication may be performed in various ways, such as communication between the access network device and the terminal device via a point-to-point transmission method, communication between the access network device and the terminal device via a multi-hop (or relay) transmission method, communication between multiple access network devices and the terminal device via a dual connectivity (DC) or multi-connection transmission method, 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 may be uplink, downlink, access link, backhaul link, or sidelink, etc.

[0101] The terminal equipment in the embodiments of this application may refer to an access terminal, user unit, user station, mobile station, mobile platform, relay station, remote station, remote terminal, mobile device, user terminal, user equipment (UE), terminal, wireless communication device, user agent or user device. The terminal equipment may also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing devices connected to a wireless modem, in-vehicle device, wearable device, a terminal device in a 5G network or a terminal device in a future evolved public land mobile network (PLMN), etc. The embodiments of this application do not limit this.

[0102] By way of example and not limitation, in the embodiments of this application, a wearable device may also be referred to as a wearable intelligent device, which is a general term for devices developed by applying wearable technology to the intelligent design of daily wear, such as glasses, gloves, watches, clothing and shoes, etc. A wearable device is a portable device that is either directly worn on the body or integrated into the user's clothes or accessories. A wearable device is not just a hardware device, but more importantly, it realizes powerful functions through software support, data interaction and cloud interaction. Broadly speaking, wearable intelligent devices include those with complete functions and large sizes that can realize complete or partial functions without relying on a smart phone, such as smart watches or smart glasses, etc., and those that only focus on a certain type of application function and need to cooperate with other devices such as smart phones, such as various smart bracelets and smart jewelry for physical sign monitoring.

[0103] In addition, in the embodiments of this application, the terminal equipment may also be a terminal equipment in an IoT system. Its main technical feature is to connect items to the network through communication technology, so as to realize an intelligent network of human-machine interconnection and thing-thing interconnection. In the embodiments of this application, IoT technology can achieve massive connection, deep coverage and power saving of the terminal through, for example, narrow band (NB) technology.

[0104] The access network device in the embodiments of the present application may be any device with wireless transceiver functions for communicating with terminal devices. Such devices include, but are not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home evolved Node B (HeNB, or home Node B, HNB), baseband unit (BBU), access point (AP) in a wireless fidelity (WIFI) system, wireless relay device, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP), etc. It may also be a gNB in a 5G system, such as an 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, it may also be a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a distributed unit (DU), etc. It may also be a device for communicating with terminal devices in a 6G system, such as a gNB in a 6G system.

[0105] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include an active antenna unit (AAU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, implementing radio resource control (RRC), and the functions of the packet data convergence protocol (PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since the information of the RRC layer will ultimately become the information of the PHY layer, or is transformed from the information of the PHY layer, thus, in this architecture, high-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or sent by the DU + AAU. It can be understood that the access network device can be a device including one or more of the CU node, DU node, and AAU node. In addition, the CU can be classified as a network device in the radio access network (RAN), or the CU can be classified as a network device in the core network (CN), and this application does not make a limitation on this.

[0106] In different systems, the 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 radio access network may also be an ORAN architecture. In the ORAN system, the CU may also be called an O-CU (open CU), the DU may also be called an O-DU, the CU-CP may also be called an O-CU-CP, the CU-UP may also be called an O-CU-UP, and the RU may also be called an O-RU. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0107] The core network device part in the embodiments of this 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 (UDM), Unified Data Repository (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 in the core network for implementing different functions. For example, they can be combined as needed to form network slices. These core network elements can be individual devices or integrated into the same device to implement different functions. This application does not limit the specific form of the above-mentioned network elements.

[0108] It should be understood that the above naming is only defined for the convenience of distinguishing different functions and should not constitute any limitation to this application. This application does not exclude the possibility of using other naming in 5G networks and future other networks. For example, in 6G networks, some or all of the above-mentioned network elements may continue to use the terms in 5G, or other names may be used.

[0109] By way of example and not limitation, in the embodiments of this application, the CN device is used to provide user connection, user management, and bearer for services, and serves as an interface to the external network as a bearer network. This application mainly involves the AMF network element (or referred to as AMF, AMF device, AMF unit, etc.) in the core network. AMF is a control plane network function provided by the operator network, responsible for access control and mobility management of terminal devices accessing the operator network. For example, it includes functions such as mobile status management, allocation of user temporary identity identifiers, authentication and authorization of users, etc.

[0110] In the embodiments 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 a memory (also referred to as main memory). The operating system can be any one or more computer operating systems that implement service processing through processes. For example, the Linux operating system, the Unix operating system, the Android operating system, the iOS operating system, or the Windows operating system, etc. The application layer includes applications such as a browser, an address book, a word processing software, and an instant messaging software. Moreover, the embodiments of the present application 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 can 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 terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0111] In addition, various aspects or features of the present application can be implemented as a method, an apparatus, or an article of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" used in the present application covers a computer program accessible from any computer-readable device, carrier, or medium. For example, the computer-readable medium can include, but is not limited to: magnetic storage devices (such as hard disks, floppy disks, or magnetic tapes, etc.), optical discs (such as compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (such as erasable programmable read-only memories (EPROMs), cards, sticks, or key drives, etc.). In addition, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable storage medium" can include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0112] It should be understood that Figure 1 taking the communication between the access network device and the terminal device, and between the access network device and the core network device as an example, briefly illustrates a communication scenario to which the present application can be applied, without limiting other scenarios to which the present application can be applied. It should also be understood that Figure 1 is only a simplified schematic diagram for easy understanding. Other network devices or other terminal devices can also be included in the communication system.Figure 1 It is not drawn in the figure.

[0113] To facilitate the understanding of the embodiments of the present application, some basic concepts related to the present application are briefly described. It should be understood that the basic concepts introduced below are described by taking the basic concepts defined in the NR protocol as an example, but it is not limited that the embodiments of the present application can only be applied to the NR system. Therefore, the standard names that appear when describing by taking the NR system as an example are all functional descriptions, and the specific names are not limited, and only represent the functions of the devices, and can be correspondingly extended to other future systems.

[0114] 1. Network slicing: With the development of mobile communication technology, various new services and application scenarios have emerged continuously. The requirements of these services for network functions, connection performance, security, etc. vary greatly. If a single network is used to carry these services, it will be very difficult to meet the requirements of high bandwidth, low latency, high reliability, etc. at the same time. In addition, building a separate network for each service will bring huge costs. This requires that 5G can meet different service requirements while being flexible and scalable. For this reason, 5G provides customized network services for users through end-to-end network slicing (which can also be simply referred to as "slicing"). By flexibly allocating network resources and networking on demand, 5G virtualizes multiple logical subnets with different characteristics and isolated from each other on the same set of physical facilities to provide services for users specifically.

[0115] Different logical subnets are identified and distinguished by single network slice selection assistance information (S-NSSAI).

[0116] Exemplarily, each S-NSSAI may include the following contents:

[0117] 1) Slice service type (SST): Used to point to the specific characteristics and service types of the slice;

[0118] 2) Slice differentiator (SD): As a supplement to the SST, it can further distinguish multiple network slice instances that meet the same SST. This SD is an optional content of the S-NSSAI.

[0119] It should be understood that the NSSAI in the following text refers to one or more S-NSSAIs.

[0120] For the NSSAI, there are the following specific classifications:

[0121] 1) Subscribed NSSAI: Subscribed data belonging to the user;

[0122] 2) Default NSSAI: According to the operator's policy, one or more of the user's subscribed NSSAI may be set as the default NSSAI; If the UE does not carry the allowed NSSAI in the registration request message and if the default NSSAI exists, the network can use the default NSSAI to provide services to the UE.

[0123] 3) Requested NSSAI: Refers to the allowed NSSAI or configured NSSAI carried by the UE in the registration request message.

[0124] 4) Allowed NSSAI: Indicates which S-NSSAI in the NSSAI requested by the UE is 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.

[0125] 5) Configured NSSAI: Refers to the NSSAI configured by the network for the UE to use. After receiving the configuration parameters indicating the configured NSSAI, the UE knows which S-NSSAI is available in this network based on the configuration parameters. The network can indicate the configured NSSAI to the UE through the "configured NSSAI" IE in the registration accept.

[0126] 6) Rejected NSSAI: Indicates which S-NSSAI in the NSSAI requested by the UE is rejected by the network. For example, because the core network or the access network side does not support these S-NSSAI.

[0127] 7) Partially allowed NSSAI: Similar to the concept of the above allowed NSSAI, the difference is that the partially allowed NSSAI is supported in some TAs of the UE's RA.

[0128] 8) Partially rejected NSSAI: Similar to the concept of rejected NSSAI described above, the difference is that in the partially rejected NSSAI, some TAs in the UE's RA are not supported.

[0129] Specifically, the slice list supported by the access network device is pre-configured by operation, administration and maintenance (OAM) at the tracking area (TA) granularity, that is, all cells within a specific TA support the same slices. Exemplarily, one TA includes one or more cells. When establishing a communication interface with the core network (such as the NG interface), the access network device can report the slice list to the core network. If the access network device also supports CU / DU separation, the DU will send the slice list supported by each TA to the CU, and then the CU will report it to the core network.

[0130] 2. Network slice area of service (NS-AoS): Considering that when slices are deployed and decommissioned within a certain time interval, the UE and network configurations may be affected. For example, when a slice becomes unavailable or available, this may affect the allowed NSSAI and other parameters, and thus the registration area (RA) may also need to be changed. Taking Figure 2 as an example, network slice #2 is supported within the TA identified by TAC#1, and there are a total of 4 cells within this TA. Due to reasons such as deployment, the resources configured for network slice #2 in Cell#2 are suddenly limited, that is, it can be understood that no resources for network slice #2 are configured in Cell#2. Therefore, Cell#2 actually cannot provide the service of network slice #2 for the UE. To avoid impacts on the UE and the network side, NS-AoS is introduced to indicate the service area for a specific slice (the area range composed of one or more cells), with the following characteristics:

[0131] 1) NS-AoS is deployed on the RAN side, and the AMF can obtain the NS-AoS configured for each slice within the UE's RA through OAM;

[0132] 2) When the UE indicates the ability to support NS-AoS, the AMF can send the NS-AoS of the configured NSSAI to the UE through the registration accept or UE configuration update message;

[0133] 3) Possible behaviors of the UE after receiving the NS-AoS for different slices are as follows:

[0134] If the UE receives the NS-AoS for the requested NSSAI, after the UE initiates a registration request for this slice outside the NS-AoS, this slice will be determined by the AMF as the allowed NSSAI or the partially allowed NSSAI;

[0135] If the UE receives the NS-AoS for the rejected NSSAI or the partially rejected NSSAI, the UE can only initiate a registration request for these slices in the cells within the NS-AoS of the above slices;

[0136] If the UE receives the NS-AoS for the allowed NSSAI or the partially allowed NSSAI, the UE can only activate the user plane for the established PDU session within the NS-AoS of the above slices. For a connected UE, if the target cell during the UE handover is outside the NS-AoS of the slice associated with the established PDU session, then this target cell will reject this PDU session during the handover process, that is, it will not prepare RAN-side resources for this PDU session, and at the same time will indicate through the NGAP message to the AMF to notify the SMF to deactivate this PDU session.

[0137] 3. Network Slice Access Layer Group (NSAG): The access network device can notify the UE of the cell reselection priority for the slice and specific random access parameters through broadcasting, and the above information is respectively included in the System Information Block 16 (SIB16) and SIB1. Considering that the broadcasting based on the slice granularity may bring relatively large overhead to the SIB, the concept of the Slice Group (or called NSAG) is proposed, that is, grouping and identifying one or more network slices. Specifically, one or more S-NSSAIs can be mapped to obtain a specific NSAG ID, and the mapping relationship between the NSAG ID and the S-NSSAI is unique within a specific area.

[0138] 4. Relay Architecture: A relay device is included in the relay architecture. The relay device 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). Then, the relay device can be understood as a device composed of a UE and a gNB. Among them, there is an air interface connection between the UE part of the relay device (which can be called the Mobile Terminal, relay-MT) and the donor-gNB, and this air interface connection can be called the Un interface; there are communication interfaces (such as the Xn interface and the NG interface) between the gNB part of the relay device (which can be called relay-gNB) and the donor-gNB. The control plane and user plane data on the Xn interface and the NG interface can be transmitted through the DRB on the air interface between the relay-MT and the donor-gNB. It should be understood that the names of the communication interfaces involved in this application (such as the above-mentioned Un interface, Xn interface, NG interface, etc.) are all examples and do not constitute any limitation to the protection scope of this application. The names of the communication interfaces can also be other situations, which will not be elaborated here.

[0139] For example, taking the above behavior as an 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 mission of the relay-MT has been completed, and the donor-gNB will maintain a bearer mapping relationship and remap the DRB of the relay-MT 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).

[0140] Exemplarily, the above-mentioned relay device has a complete gNB function, that is, it has a complete base station-side protocol stack. The relay architecture in this application can be called NR L3 Relay.

[0141] For ease of understanding, combined with Figure 3 briefly introduce the architecture of the NR L3 Relay system.

[0142] From Figure 3 it can be seen that the NR L3 Relay system includes core network devices (such as, Figure 3 the AMF / UPF shown in Figure 3The donor-gNB (host base station) and gNB (base station) shown in Figure 3 the relay shown in Figure 3 (the relay includes a relay-MT and a relay-gNB), and the terminal device (e.g., Figure 3 the UE shown in Figure 3 ), where there is a communication interface between the UE and the relay-gNB of the relay device (e.g.,

[0143] the Uu interface shown in

[0144] ), and there is a communication interface between the relay-MT of the relay device and the host base station (e.g.,

[0145] the Un interface shown in Figure 1 ).

[0146] 5. Data transmission in the L3 Relay system: In the NR system, the establishment of the DRB of the UE is triggered by the establishment of the PDU session of the UE. That is to say, in the NR system, only when the UE wants to initiate a service, the base station will establish a DRB corresponding to the QoS, and it does not support directly triggering the establishment of the DRB by the base station. As can be seen from the above, the relay device includes a relay-MT and a relay-gNB. Among them, the relay-MT can be connected to the host base station through the air interface, 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 can provide the PDU session corresponding to the backhaul DRB for the UE, which can be triggered by the UE's service. Suppose the UE wants to establish a PDU session associated with Slice#1, then 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 the same as (i.e., Slice#1) or different from the service requested by the UE, which is not limited, so as to realize the establishment of the DRB between the relay-MT and the donor-gNB to provide relay backhaul services for the UE. The above briefly introduces the scenarios where the communication method provided in the embodiments of the present application can be applied, and introduces the basic concepts that may be involved in the embodiments of the present application, and introduces the L3 Relay system and the data transmission method in the L3 Relay system 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 this 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 slice services to fail or the established services to be interrupted.To facilitate the understanding of the possible problems in the data transmission method in the above L3 Relay system, the following is described in conjunction with Figure 4 for illustration.

[0147] As Figure 4 shown, assume that the TA identified by TAC#1 is the RA of the UE, and the list of network slices supported within TA#1 is {Network Slice #1, Network Slice #2} (the "{}" indicates a list). TA#1 includes three static cells, namely Cell#1, Cell#2, and Cell#3. Among them, Cell#1 has not allocated any resources for Network Slice #1. The relay device is a movable relay device (such as a vehicle-mounted relay device, etc.). The relay-gNB of the relay device includes Cell#4, which can support Network Slice #1 and Network Slice #2, and resources have been allocated for both the above Network Slice #1 and Network Slice #2. This Cell#4 moves together with the relay device and is not a deployed static cell.

[0148] Assume that the UE is accessing the cell of the relay-gNB (i.e., Cell#4), and both the UE and the 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 (such as the NCGI of the cell) of Cell#2, Cell#3, and Cell#4, 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.

[0149] 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 the network slice #1, the data plane of the PDU session #1 will not be activated, and the 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 equipment part of the relay device (relay-gNB)), the service cell is the cell (i.e., Cell#4) of the relay device (e.g., the access network equipment part (relay-gNB)) rather than the service cell (i.e., Cell#1) of the relay device (e.g., the terminal equipment part (relay-MT)) . 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 equipment part (relay-MT)) 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.

[0150] 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) cannot 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.

[0151] It should be understood that the communication method provided in the embodiment of the present application can be applied to a relay system, for example, Figure 3 The communication system shown in .

[0152] 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 may be a device or a network element, or a functional module in a device or a network element that can call and execute a program.

[0153] Figure 5 This is a schematic flow chart of a communication method provided by the present application. It includes the following steps:

[0154] S501, The first terminal device sends request message #1 to the first core network device. Correspondingly, the first core network device receives request message #1 from the first terminal device.

[0155] The first core network device involved in this embodiment may be the aforementioned AMF. The name of the first core network device is not limited in this embodiment. Devices capable of implementing the functions of the first core network device in this embodiment are within the protection scope of this application. For ease of description, hereinafter, the first core network device is taken as AMF #1 as an example for illustration. The first terminal device in this embodiment may be any terminal device. For ease of description, hereinafter, the first terminal device is taken as UE #1 as an example for illustration.

[0156] Specifically, this request message #1 is used to request the establishment of a second PDU session associated with the fourth network slice. Exemplarily, request message #1 may be an uplink NAS message containing a PDU session establishment request message.

[0157] As can be seen from the above, in this embodiment, UE #1 may initiate request message #1 for establishing a second PDU session associated with the fourth network slice. This request message #1 is carried in the NAS message of UE #1 and sent to the AMF (referred to as AMF #1) serving the terminal device. After receiving request message #1 in this embodiment, there are the following two possible ways for AMF #1:

[0158] Way 1: AMF #1 may instruct the relay device to establish DRB #1 corresponding to the second PDU session for UE #1.

[0159] In the case shown by Way 1, Figure 5 The method flow shown may further include:

[0160] S502, AMF #1 sends message #1 to the relay device.

[0161] Specifically, this 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 (such as Figure 5 DRB #1 shown in, that is, the RRC connection end point of UE #1 is at the relay device (e.g., the access network device part (relay-gNB) of the relay device). The relay device (e.g., the access network device part (relay-gNB) of the relay device) generates NGAP messages related to UE #1, and the host access network device transparently transmits the NGAP messages of UE #1).

[0162] Optionally, the AMF #1 indicates, via an NGAP message (such as an initial context setup request message), to the relay device (e.g., the access network device part of the relay device (relay-gNB)) to establish a DRB #1 corresponding to the second PDU session for the UE #1.

[0163] S503, the relay device establishes the DRB #1.

[0164] In the case shown in this Mode 1, the GTP-U tunnel corresponding to the second PDU session (such as Figure 5 the GTP-U tunnel #1 shown in

[0165] Mode 2: The AMF #1 may indicate to the host access network device to establish a DRB #2 corresponding to the second PDU session for the UE #1.

[0166] In the case shown in this Mode 2, Figure 5 the method flow shown may further include:

[0167] S504, the AMF #1 sends Message #2 to the host access network device.

[0168] Specifically, this Message #2 is used to indicate to the host access network device (donor-gNB) to establish a DRB #2 corresponding to the second PDU session for the UE #1 (such as Figure 5 the DRB #2 shown in

[0169] Optionally, the AMF #1 indicates, via an NGAP message (such as an initial context setup request message), to the host access network device to establish a DRB #2 corresponding to the second PDU session for the UE #1.

[0170] S505, the host access network device establishes the DRB #2.

[0171] In the case shown in this Mode 2, the GTP-U tunnel corresponding to the second PDU session (such as Figure 5 the GTP-U tunnel #2 shown in

[0172] Further, the relay device may initiate a request to establish a first PDU session associated with a first network slice to a second core network device (e.g., AMF#2) serving the relay device via a NAS message based on a fourth network slice associated with the second PDU session of UE#1. The fourth network slice and the first network slice may be the same or different. Then Figure 5 The method flow shown also includes:

[0173] S506, the relay device sends request message #2 to AMF#2. Correspondingly, AMF#2 receives request message #2 from the relay device.

[0174] Specifically, this request message #2 is used to request the establishment of a first PDU session associated with a first network slice. Exemplarily, request message #2 may be an uplink NAS message containing a PDU session establishment request message.

[0175] S507, AMF#2 sends message #3 to the host access network device.

[0176] Specifically, this 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 of the relay device (relay-MT)). Figure 5 As shown in DRB#3, that is, the RRC connection of the relay device terminates 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 of the relay device (relay-MT)).

[0177] Optionally, AMF#2 may instruct the host access network device to establish DRB#3 corresponding to the first PDU session via an NGAP message (e.g., an initial context setup request message).

[0178] S508, the host access network device establishes DRB#3.

[0179] The GTP-U tunnel corresponding to the first PDU session (e.g., Figure 5 As shown in GTP-U tunnel #3) is established between the host access network device and AMF#2. DRB#3 may be used to carry data on the backhaul link, and the backhaul link is the backhaul link for transmitting data of the second PDU session of UE#1. Specifically, the backhaul link is used to carry data between the relay device and the host access network device.

[0180] As a possible implementation, if the relay device moves from Cell #2 to the first cell (such as Cell #1), that is, the resident cell (or called serving 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.

[0181] Optionally, both Cell #1 and Cell #2 belong to the same base station, that is, the first cell and Cell #2 both 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 CU) handover within the station.

[0182] 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 (between CUs) handover between stations. Compared with the intra-CU handover within the station, there are additional XnAP-related handover messages, which will not be elaborated here.

[0183] As another possible implementation, if the resident cell of the relay device is updated to the first cell.

[0184] 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.

[0185] Figure 5 The shown method flow further includes:

[0186] S510, the relay device or the host access network device determines that the first cell is outside the service area of the first network slice.

[0187] As can be seen from the above, the first cell is the resident cell of the relay device, the first network slice is associated with the first PDU session, the DRB corresponding to the first PDU session (i.e., the above 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, this backhaul link is used to carry the data between the relay device and the host access network device, and UE #1 is the terminal device accessing the relay device.

[0188] Exemplarily, after the relay device or the host access network device determines that the first cell is outside the service area of the first network slice, the subsequent process includes several situations shown in the following Possibility 1 to Possibility 8. The following will be described with reference to Figure 1 Figure 1.

[0189] As a possible implementation, the host access network device executes step S510, that is, the host access network device determines that the first cell is outside the service area of the first network slice, including:

[0190] The host access network device can learn that the first cell is outside the service area of the first network slice by determining that no resources are allocated for the first network slice in the resident cell of the relay device.

[0191] For example, if the host access network device determines that the first cell (such as the serving cell after handover) where the relay device resides does not allocate resources for the first network slice associated with the first PDU session, it can reject the 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 an internal core network interface).

[0192] Exemplarily, the NGAP message can be a message related to PDU session modification, such as a PDU session resource notify message or a path switch request message, etc.

[0193] Possibility 1: The host access network device determines to deactivate the second PDU session of UE#1.

[0194] Corresponding to the above-mentioned method 1, the relay device (for example, the access network device part (relay-gNB) of the relay device) establishes DRB#1. In the case of Possibility 1, the host access network device can instruct the relay device (for example, the terminal device part (relay-MT) of the relay device) to let the relay device (for example, the access network device part (relay-gNB) of the relay device) release the resources prepared for the second PDU session of UE#1 (including releasing its corresponding DRB#1).

[0195] Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2. In the case of Possibility 1, the host access network device can directly release the resources prepared for the second PDU session of UE#1.

[0196] If the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device has not completed the release of the resources prepared for the second PDU session of UE#1 (e.g., 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 does not execute, or the host access network device directly releases the resources prepared for the second PDU session of UE#1 but does not execute), then in the subsequent process, when AMF#1 deactivates the second PDU session of UE#1, it can also indicate to 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.

[0197] Exemplarily, in the case shown in FIG. 1, it may involve the host access network device sending an indication to deactivate the second PDU session.

[0198] Optionally, the host access network device sending the deactivation indication includes but is not limited to the following methods. For ease of understanding, the following is described in conjunction with Figure 6 for illustration.

[0199] Method 1.1: The host access network device instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0200] In the case shown in Method 1.1, Figure 6 the method flow shown includes:

[0201] S611, the host access network device sends the first indication information to AMF#2. Correspondingly, AMF#2 receives the first indication information from the host access network device.

[0202] Specifically, the first indication information instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0203] Exemplarily, the first indication information can be carried in the existing NGAP signaling to indicate to AMF#2, or carried in the newly added NGAP signaling to indicate to AMF#2, which is not limited in this application. For example, the first indication information can be carried in the information indicating AMF#2 to deactivate the first PDU session. Also, for example, the first indication information is the information indicating AMF#2 to deactivate the first PDU session. If the first indication information is the information indicating AMF#2 to deactivate the first PDU session, then in this embodiment, after AMF#2 receives the first indication information, in response to this 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.

[0204] Exemplarily, in the case shown in Mode 1.1, the first indication information includes at least one of the following information:

[0205] The identifier of AMF#1, the identifier of UE#1, or the identifier of the second PDU session.

[0206] 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.

[0207] Optionally, corresponding to the above Mode 1, the first indication information may further provide the UE NGAP ID assigned by the relay device (e.g., the access network device part of the relay device (relay-gNB)) to UE#1.

[0208] Optionally, corresponding to the above Mode 2, the first indication information may further provide the UE NGAP ID assigned by the host access network device to UE#1.

[0209] It should be noted that the identifier of AMF#1, the identifier of UE#1, or the identifier of the second PDU session involved in this application are only examples and do not constitute any limitation to the protection scope of this application. For example, any information that can be used to identify AMF#1 is within the protection scope of this application. For another example, any information that can be used to identify UE#1 is within the protection scope of this application. For yet another example, any information that can be used to identify the second PDU session is within the protection scope of this application. Here, no further examples will be given one by one.

[0210] S612, AMF#2 sends the sixth indication information to AMF#1. Correspondingly, AMF#1 receives the sixth indication information from AMF#2.

[0211] Specifically, based on the first indication information sent by the host access network device, AMF#2 can send the sixth indication information to AMF#1, and the sixth indication information instructs AMF#1 to deactivate the second PDU session of UE#1.

[0212] For example, if the AMF#2 determines that the AMF serving the 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, it may send the sixth indication information to this AMF#1. The sixth indication information is used to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0213] Exemplarily, the sixth indication information includes the identifier of UE#1 received from the first indication information and the identifier of the second PDU session.

[0214] Optionally, corresponding to the above-mentioned manner 1, the sixth indication information may further provide the UE NGAP ID assigned by the relay device (e.g., the access network device part of the relay device (relay-gNB)) for UE#1.

[0215] Optionally, corresponding to the above-mentioned manner 2, the sixth indication information may further provide the UE NGAP ID assigned by the host access network device for UE#1.

[0216] S613, AMF#1 deactivates the second PDU session.

[0217] Specifically, in the case shown in manner 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.

[0218] Manner 1.2: The host access network device instructs AMF#1 to deactivate the second PDU session of UE#1.

[0219] In the case shown in manner 1.2, Figure 6 the method flow shown further includes:

[0220] S614, the host access network device sends the first indication information to AMF#1, and correspondingly, AMF#1 receives the first indication information from the host access network device.

[0221] Specifically, after rejecting the first PDU session admission of the relay device, the host access network device instructs AMF#1 to deactivate the second PDU session of UE#1 through the first indication information.

[0222] Exemplarily, in the case shown in manner 1.2, the first indication information includes the identifier of UE#1 and the identifier of the second PDU session.

[0223] Optionally, corresponding to the above-mentioned Method 1, the first indication information may further provide the UE NGAP ID allocated by the relay device (e.g., the access network device part of the relay device (relay-gNB)) for UE#1.

[0224] Optionally, corresponding to the above-mentioned Method 2, the first indication information may further provide the UE NGAP ID allocated by the host access network device for UE#1.

[0225] S615, AMF#1 deactivates the second PDU session.

[0226] Reference may be made to the description of step S613 in the above-mentioned Method 1.1, which will not be elaborated here.

[0227] Method 1.3: The host access network device instructs UE#1 to initiate the deactivation of the second PDU session.

[0228] In the case shown in Method 1.3, Figure 6 the method flow shown further includes:

[0229] S616, the host access network device sends the first indication information to UE#1. Correspondingly, UE#1 receives the first indication information from the host access network device.

[0230] Specifically, after rejecting the first PDU session admission of the relay device, the host access network device instructs UE#1 to initiate the deactivation of the second PDU session through the first indication information.

[0231] 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)). The first indication information sent by the host access network device to UE#1 in step S616 may be: the host access network device sends the first indication information to the relay device (e.g., the terminal device part of the relay device (relay-MT)), and then the relay device (e.g., the access network device part of the relay device (relay-gNB)) sends the first indication information to UE#1 through an RRC message.

[0232] Optionally, corresponding to the above-mentioned Method 2, DRB#2 is established by the host access network device. The first indication information sent by the host access network device to UE#1 in step S616 may be: the host access network device directly sends the first indication information to UE#1 through an RRC message.

[0233] S617, UE#1 sends the seventh indication information to AMF#1. Correspondingly, AMF#1 receives the seventh indication information from UE#1.

[0234] Specifically, after receiving the above first indication information, UE#1 can request AMF#1 to deactivate the second PDU session of UE#1 in response to the first indication information through the seventh indication information.

[0235] 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 UE can request to deactivate the second PDU session of UE#1 from AMF#1 through a PDU session management procedure (such as a PDU session release or modification procedure).

[0236] Exemplarily, the identifier of the second PDU session is included in the seventh indication information.

[0237] S618, AMF#1 deactivates the second PDU session.

[0238] Reference can be made to the description of step S613 in the above method 1.1, which will not be elaborated here.

[0239] As another possible implementation, the relay device executes step S510, that is, the relay device determines that the first cell is outside the service area of the first network slice, including:

[0240] The relay device determines that the identifier of the first cell does not belong to any of the identifiers of at least one cell included in the first cell identifier and the first service area information, 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,

[0241] The relay device determines that the first PDU session is deactivated.

[0242] For example, the relay device can determine that the currently resident 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, if the NS-AoS information of the first network slice (i.e., the above 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 identifiers of Cell#2 and Cell#3, and the identifier of the above first cell is not any of the identifiers of Cell#2 and Cell#3, and the relay device can determine that the currently resident first cell is outside the NS-AoS of the first network slice.

[0243] Also for example, the relay device senses that the first PDU session is deactivated by AMF#2. For example, the relay device (such as the terminal device part of the relay device (relay-MT)) receives the indication information that the first PDU session is deactivated.

[0244] Possibility 2: The relay device determines to deactivate the second PDU session of UE#1.

[0245] 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. In the case of Possibility 2, the relay device (e.g., the access network device part of the relay device (relay-gNB)) can directly release the resources prepared for the PDU session #1 of the UE.

[0246] Corresponding to the above-mentioned Method 2, the host access network device establishes DRB#2. In the case of Possibility 2, the relay device can instruct the host access network device to release the resources prepared for the second PDU session of UE#1.

[0247] If the relay device (e.g., the access network device part of the relay device (relay-gNB)) or the host access network device has not completed the release of the resources prepared for the second PDU session of UE#1 (for example, the relay device has not executed the direct release of the resources prepared for the second PDU session of UE#1, or the above-mentioned relay device has not instructed the host access network device to release the resources prepared for the second PDU session of UE#1), then when AMF#1 deactivates the second PDU session of UE#1 in the subsequent process, 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.

[0248] Exemplarily, in the case of Possibility 2, it involves the relay device sending an indication to deactivate the second PDU session.

[0249] Optionally, the relay device sending the deactivation indication includes but is not limited to the following methods. For the sake of easy understanding, the following is combined with Figure 7 for illustration:

[0250] Method 2.1: The relay device instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0251] In the case of Method 2.1, Figure 7 the method flow shown also includes:

[0252] S721, the relay device sends the first indication information to AMF#2. Correspondingly, AMF#2 receives the first indication information from the relay device.

[0253] Specifically, the first indication information instructs AMF#2 to instruct AMF#1 to deactivate the second PDU session of UE#1.

[0254] Exemplarily, the first indication information may be carried in the existing NGAP signaling and indicated to AMF#2, or carried in the newly added NGAP signaling and indicated to AMF#2, which is not limited in this application. For example, the first indication information may be carried in the information indicating that AMF#2 deactivates the first PDU session. Further, for example, the first indication information is the information indicating that AMF#2 deactivates the first PDU session. If the first indication information is the information indicating that AMF#2 deactivates the first PDU session, then in this embodiment, after receiving the first indication information, AMF#2 not only executes the process of deactivating the first PDU session in response to the first indication information, but also executes the process of instructing AMF#1 to deactivate the second PDU session of UE#1.

[0255] Exemplarily, in the case shown in Method 2.1, the first indication information includes at least one of the following information:

[0256] The identifier of AMF#1, the identifier of UE#1, or the identifier of the second PDU session.

[0257] The definitions of the identifier of AMF#1, the identifier of UE#1, and the identifier of the second PDU session in this embodiment may refer to the descriptions 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 elaborated here.

[0258] Optionally, corresponding to the above Method 1, the first indication information may further provide the UE NGAP ID assigned by the relay device (e.g., the access network device part of the relay device (relay-gNB)) for UE#1.

[0259] Optionally, corresponding to the above Method 2, the first indication information may further provide the UE NGAP ID assigned by the host access network device for UE#1.

[0260] S722. AMF#2 sends the sixth indication information to AMF#1. Correspondingly, AMF#1 receives the sixth indication information from AMF#2.

[0261] Reference may be made to the description of step S612 in the above Method 1.1, and will not be elaborated here.

[0262] S723. AMF#1 deactivates the second PDU session.

[0263] Reference may be made to the description of step S613 in the above Method 1.1, and will not be elaborated here.

[0264] Method 2.2: The relay device instructs AMF#1 to deactivate the second PDU session of UE#1.

[0265] In the case shown in Mode 2.2, Figure 7 The method flow shown also includes:

[0266] S724. The relay device sends first indication information to AMF#1. Correspondingly, AMF#1 receives the first indication information from the relay device.

[0267] Specifically, after the relay device determines that the resident cell where it is currently located is outside the NS-AoS of the first network slice, the relay device (e.g., the access network device part of the relay device (relay-gNB)) uses the first indication information to instruct AMF#1 to deactivate PDU session #1 of the UE.

[0268] Exemplarily, in the case shown in Mode 2.2, the first indication information includes the identifier of UE#1 and the identifier of the second PDU session.

[0269] Optionally, corresponding to the above Mode 1, the first indication information may further provide the UE NGAP ID assigned by the relay device (e.g., the access network device part of the relay device (relay-gNB)) for UE#1.

[0270] Optionally, corresponding to the above Mode 2, the first indication information may further provide the UE NGAP ID assigned by the host access network device for UE#1.

[0271] Optionally, corresponding to the above Mode 1, DRB#1 is established by the relay device (e.g., the access network device part of the relay device (relay-gNB)). Step S724. The relay device (e.g., the terminal device part of the relay device (relay-MT)) sending the first indication information to AMF#1 may be: the first indication information is carried in an NGAP message and is relayed by the relay device (e.g., the access network device part of the relay device (relay-gNB)) through the host access network device to AMF#1.

[0272] Optionally, corresponding to the above Mode 2, DRB#2 is established by the host access network device. Step S724. The relay device (e.g., the terminal device part of the relay device (relay-MT)) sending the first indication information to AMF#1 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, where the host access network device may only indicate to AMF#1 through an NGAP message after receiving an indication from the relay device (e.g., the terminal device part of the relay device (relay-MT)).

[0273] S725. AMF#1 deactivates the second PDU session.

[0274] Reference may be made to the description of step S613 in the above-mentioned method 1.1, which will not be elaborated here.

[0275] Method 2.3: The relay device (e.g., the terminal device part of the relay device (relay-MT)) instructs UE#1 to initiate the deactivation of the second PDU session.

[0276] In the case shown in Method 2.3, Figure 7 The method flow shown further includes:

[0277] S726, the relay device sends the first indication information to UE#1, and correspondingly, UE#1 receives the first indication information from the relay device.

[0278] Specifically, after the relay device determines that the currently camped cell is outside the NS-AoS of the first network slice or determines that the first PDU session is activated, it instructs UE#1 to initiate the deactivation of the second PDU session through the first indication information.

[0279] S727, UE#1 sends the seventh indication information to AMF#1, and correspondingly, AMF#1 receives the seventh indication information from UE#1.

[0280] Reference may be made to the description of step S617 in the above-mentioned method 1.3, which will not be elaborated here.

[0281] S728, AMF#1 deactivates the second PDU session.

[0282] Reference may be made to the description of step S613 in the above-mentioned method 1.1, which will not be elaborated here.

[0283] It should be noted that the first indication information is involved in the above-mentioned Method 1.1 to Method 2.3. The receiving end, sending end or the content included in the first indication information may be different in different methods. For the sake of distinction, it can be called the first indication information #1, the first indication information #2, etc. It should be understood that the message names in this application do not impose any limitation on the solution.

[0284] In the solutions shown in the above-mentioned Possibility 1 and Possibility 2, when 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 the data of the backhaul link, the first core network device serving the first terminal device can be instructed to deactivate the second PDU session, so as to avoid the service failure or interruption caused by the first terminal device continuing to perform service transmission based on the second PDU session.

[0285] In addition, as another implementation, 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, the network slice associated with the first PDU session can be updated from the first network slice to the second network slice, and there are available resources for the second network slice in the first cell, so that the DRB corresponding to the first PDU session associated with the second network slice can continue to provide the backhaul link for the second PDU session of the first terminal device. Thus, the first terminal device can continue to perform service transmission based on the second PDU session. The following Possibility 3 is this implementation method.

[0286] 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.

[0287] For ease of understanding, the following combines Figure 8 to introduce in detail how to update the network slice associated with the first PDU session in the case shown in Possibility 3. In the case shown in Possibility 3, Figure 8 the method flow shown includes:

[0288] S831, the host access network device sends the third indication information to AMF#2. Correspondingly, AMF#2 receives the third indication information from the host access network device.

[0289] The third indication information is used to indicate deactivating the first protocol data unit PDU session.

[0290] S832, AMF#2 updates the network slice associated with the first PDU session.

[0291] Specifically, in the case shown in this Possibility 3, after receiving the third indication information from the host access network device, AMF#2 does not deactivate the first PDU session, but updates the network slice associated with the first PDU session, and the updated network slice has available resources in the first cell.

[0292] S833, AMF#2 sends the first message to the host access network device. Correspondingly, the host access network device receives the first message from AMF#2.

[0293] 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 the first message (such as, the NGAP message).

[0294] 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.

[0295] Exemplarily, 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. Wherein, alternative S-NSSAI refers to a slice 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 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.

[0296] 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 the third network slice 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.

[0297] Possibility 4: The host access network device or relay device reselects the DRB used for backhaul for the second PDU session of UE#1 from other established backhaul DRBs (corresponding to other PDU sessions).

[0298] 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 may 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 are released.

[0299] Furthermore, the host access network device or the relay device may save the association relationship between the DRB associated with the second PDU session and the backhaul DRB (i.e., the DRB corresponding to the above-mentioned third PDU session), and / or, the host access network device or the relay device may save the association relationship between the backhaul DRB and the GTP-U tunnel corresponding to the second PDU session.

[0300] As another implementation, the relay device may keep the identifier of the serving cell provided by the relay device consistent with the identifier of the serving cell where the relay device is currently located. It can be understood that the serving cell of the terminal device accessing the relay device is extended as the serving cell of the relay device. If the serving 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 learn that the serving cell where it is currently located is not within the service area of a certain network slice. The following possibility 5 is this implementation.

[0301] Possibility 5: The serving cell of UE#1 is extended as the serving cell of the relay device, that is, the cell identifier of the relay device is kept consistent with the serving cell of the relay device.

[0302] In the case of possibility 5, the relay device sets the identifier of the serving cell provided by the relay device for UE#1 to the identifier of the first cell.

[0303] Exemplarily, due to the mobility of the relay device, the serving cell of the relay device will change. For example, after handover, the serving cell of the relay device becomes Cell#1, and the cell identifiers on the relay device will all be changed to the identifier of Cell#1, that is, Cell#4 will also be updated to Cell#1. At this time, the serving cell of UE#1 accessing the relay device is consistent with the serving cell of the relay device.

[0304] Furthermore, after the relay device updates the cell identifier on the relay device, UE#1 can determine that the serving cell where it is currently located is not within the service area of the fourth network slice. Among them, the fourth network slice in this embodiment is the same as the first network slice.

[0305] It should be understood that in the case where the terminal device determines that the serving cell where it is currently located 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 elaborated here.

[0306] It should be noted that in the case of possibility 5, the above-mentioned step S510 can be an optional step, that is, the relay device does not need to determine whether the first cell is outside the service area of the first network slice. When the serving cell of the relay device changes, the relay device can set the identifier of the serving cell provided by the relay device for UE#1 to the identifier of the serving cell of the relay device.

[0307] As another implementation, 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, the second service area information can also be updated so that the updated second service area information does not include the identifier of the second cell (i.e., the cell where the first terminal device camps), and the updated second service area information is sent to the first terminal device. Thus, 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 cell where the first terminal device camps 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 service failure or interruption caused by the first terminal device continuing to perform service transmission based on the second PDU session. The following possibilities 6 and 7 are this implementation.

[0308] Possibility 6: The host access network device or the relay device instructs AMF#1 to update the NS-AoS of the fourth network slice for UE#1.

[0309] For ease of understanding, the following combines Figure 9 to introduce in detail how AMF#1 updates the NS-AoS of the fourth network slice for UE#1 in the case shown in Possibility 6. In the case shown in Possibility 6, Figure 9 the method flow shown includes:

[0310] S921, the host access network device or the relay device sends the fourth indication information to AMF#1. Correspondingly, AMF#1 receives the fourth indication information from the host access network device or the relay device.

[0311] 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 currently camped cell of UE#1 (such as Cell#4) should be removed from the updated NS-AoS information.

[0312] Optionally, if the fourth indication information is sent by the relay device, 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)). Then it can be transparently transmitted to AMF#1 by the host access network device. Corresponding to the above-mentioned method 2, DRB#2 is established by the host access network device. Then the relay device can first instruct the host access network device, and then the host access network device instructs AMF#1.

[0313] S922, AMF#1 updates the second service area information.

[0314] Specifically, in response to the above-mentioned 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, and the updated second service area information does not include the identifier of the second cell (i.e., the cell where UE #1 is currently camped). For example, the cell where UE #1 is currently camped (such as Cell #4) should be removed from the updated second service area information.

[0315] S923, AMF #1 sends the updated second service area information to UE #1. Correspondingly, UE #1 receives the updated second service area information from AMF #1.

[0316] S924, UE #1 determines that the cell where it is currently camped is not within the service area of the fourth network slice.

[0317] Specifically, in the case where the terminal device determines that the cell where it is currently camped 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 elaborated here.

[0318] 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.

[0319] For ease of understanding, the following combines Figure 10 to introduce in detail how to obtain the NS-AoS of the new fourth network slice in the case shown in Possibility 7. In the case shown in Possibility 7, Figure 10 the method flow shown includes:

[0320] S1031, the host access network device or relay device sends the fourth indication information to UE #1. Correspondingly, UE #1 receives the fourth indication information from the host access network device or relay device.

[0321] 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 the TAU process) to achieve instructing the first core network device to update the second service area information.

[0322] Optionally, if the fourth indication information is sent by the host access network 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 first indicate to the relay device (e.g., the terminal device part of the relay device (relay-MT)), and then the relay device (e.g., the access network device part of the relay device (relay-gNB)) indicates to UE#1. Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2, and then it can be relayed to UE#1 by the relay device (e.g., the access network device part of the relay device (relay-gNB)).

[0323] S1032, UE#1 sends the fifth indication information to AMF#1.

[0324] The fifth indication information is used to indicate the first core network device to update the second service area information, and the second service area information is the 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.

[0325] Optionally, the host access network device or the relay device can carry the identifier of the resident cell of the relay device (e.g., the terminal device part of the relay device (relay-MT)) in this NAS message, such as the NCGI of Cell#1.

[0326] 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 this resident cell can be directly carried in the NAS message of the UE by the relay device (e.g., the terminal device part of the relay device (relay-MT)), or when the host access network device relays this NAS message to AMF#1 of UE#1, it additionally carries the identifier of the resident cell through an NGAP message. Or,

[0327] Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2. The identifier of this resident cell can be indicated to the host access network device when the relay device (e.g., the terminal device part of the relay device (relay-MT)) relays the NAS message of UE#1, and then the host access network device sends it to AMF#1 of UE#1 together through an NGAP message, or the host access network device directly indicates it to AMF#1 of UE#1 through an NGAP message when relaying the NAS message of UE#1.

[0328] S1033, AMF#1 updates the second service area information.

[0329] 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 outside the service area of the first network slice, and thus determine 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, and the updated second service area information does not include the identifier of the second cell (i.e., the cell where UE #1 is currently camped). For example, the cell where UE #1 is currently camped (such as Cell #4) should be removed from the updated second service area information.

[0330] S1034. AMF #1 sends the updated second service area information to UE #1. Correspondingly, UE #1 receives the updated second service area information from AMF #1. The description of step S923 in the above possible scenario 6 can be referred to here and will not be elaborated further.

[0331] S1035. UE #1 determines that the cell where it is currently camped is not within the service area of the fourth network slice.

[0332] Specifically, in the case where the terminal device determines that the cell where it is currently camped 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 elaborated further here.

[0333] It should be noted that in the case described in possible scenario 7, the above steps S510 and S1031 can be optional steps, that is, UE #1 can initiate the update of the second service area information on its own initiative.

[0334] As another implementation method, in the case 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 the data of the backhaul link, it is also possible to indicate that there is no resource for the backhaul link of the relevant data of UE #1, so as to avoid the service failure or interruption caused by the first terminal device continuing to perform service transmission based on the second PDU session. The following possible scenario 8 is this implementation method.

[0335] Possible scenario 8: The host access network device or the relay device indicates to UE #1 that there is no resource for the backhaul link provided by the relay device for UE #1.

[0336] For ease of understanding, the following combines Figure 11 to introduce in detail the method flow in the case shown in possible scenario 8. Figure 11 The method flow shown includes:

[0337] S1141. The host access network device or the relay device sends the eighth indication information to UE #1. Correspondingly, UE #1 receives the eighth indication information from the host access network device or the relay device.

[0338] 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 there are no resources in the fourth network slice or the NSAG associated with the fourth network slice to which the DRB providing the backhaul link for UE#1 by the relay device is associated, so as to indicate that the second cell does not belong to the service area of the fourth network slice.

[0339] This eighth indication information can be sent in the form of an RRC message or a broadcast message.

[0340] 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. This eighth indication information can be directly carried in the NAS message of the UE by the relay device (e.g., the terminal device part of the relay device (relay-MT)), or the host access network device, while transparently transmitting this NAS message to AMF#1 of UE#1, additionally carries the identifier of the resident cell through an NGAP message. Or,

[0341] Corresponding to the above-mentioned method 2, the host access network device establishes DRB#2. This eighth indication information can be indicated to the host access network device when the relay device (e.g., the terminal device part of the relay device (relay-MT)) transparently transmits the NAS message of UE#1, and then the host access network device sends it to AMF#1 of UE#1 together through an NGAP message, or the host access network device directly indicates it to AMF#1 of UE#1 through an NGAP message when transparently transmitting the NAS message of UE#1.

[0342] S1142, UE#1 determines that the currently resident cell is not within the service area of the fourth network slice.

[0343] Specifically, in the case where the terminal device determines that the currently 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 elaborated here.

[0344] It should be noted that in the case shown in FIG. 8, in the L3 Relay scenario, UE#1 may regard the cell without resources on the backhaul link as outside the NS-AoS of the slice associated with the data transmitted by the UE on this backhaul (even if the serving cell of UE#1 is allocated resources for this slice, such as Cell#4 is allocated resources for the fourth network slice, but the DRB providing backhaul for UE#1 is not allocated resources in the first cell). Or, UE#1 may also remove the serving cell of UE#1 (i.e., Cell#4) from the NS-AoS saved for the fourth network slice (or for the slice associated with the NSAG in the indication information, for this NSAG), then UE#1 determines that the current serving cell is not within the service area of the fourth network slice.

[0345] It should be understood that the magnitudes of the sequence numbers of the above processes do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0346] It should also be understood that in various embodiments of the present application, without special instructions and logical conflicts, the terms and / or descriptions between different embodiments are consistent and can be mutually referred to. The technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0347] It should also be understood that in some of the above embodiments, devices in the existing network architecture are mainly used as examples for illustrative purposes (such as host access network devices, relay devices, first core network devices, second core network devices, or first terminal devices, etc.). It should be understood that the specific forms of the devices are not limited in the embodiments of the present application. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0348] It can be understood that in each of the above method embodiments, the methods and operations implemented by the devices (such as host access network devices, relay devices, first core network devices, second core network devices, or first terminal devices) can also be implemented by components of the devices (such as chips or circuits).

[0349] Above, in combination with Figures 5 to 11 The communication method provided by the embodiments of the present application has been described in detail. The above communication method has been introduced mainly from the perspective of the interaction between the protocol layers of the terminal device. It can be understood that in order for the terminal device to implement the above functions, it includes the corresponding hardware structure and / or software modules for executing each function.

[0350] Those skilled in the art should be able to realize that, for the units and algorithm steps of each example described in combination with 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 certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described function for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0351] The following will Figures 12 to 14 describe in detail the communication device provided by the present application. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments. Therefore, for the content not described in detail, reference can be made to the above method embodiments. For the sake of brevity, some content will not be repeated.

[0352] Embodiments of the present application can divide functional modules for the transmitting end device or the receiving end device according to the above method examples. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. It should be noted that the division of modules in the embodiments of the present application is illustrative, only a logical function division, and there can be other division methods in actual implementation. The following will take the example of dividing each functional module corresponding to each function for illustration.

[0353] Figure 12 is a schematic block diagram of a communication device 10 provided by 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. The processing module 12 is used for data processing, or rather, the transceiver module 11 is used to perform operations related to reception and transmission, and the processing module 12 is used to perform other operations except reception and transmission. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0354] Optionally, the device 10 may further include a storage module 13. The storage module 13 can be used to store instructions and / or data. The processing module 12 can read the instructions and / or data in the storage module so that the device can implement the actions of the devices in the foregoing method embodiments.

[0355] In one design, the device 10 can correspond to the host access network device or the relay device in the above method embodiments, or a component (such as a chip) of the host access network device or the relay device.

[0356] The device 10 can implement the steps or processes corresponding to those performed by the host access network device or the relay device in the above method embodiments. Among them, the transceiver module 11 can be used to perform the operations related to the transceiver of the host access network device or the relay device in the above method embodiments, and the processing module 12 can be used to perform the operations related to the processing of the host access network device or the relay device in the above method embodiments.

[0357] In a possible implementation manner, the processing module 12 is configured to determine that the first cell is outside the service area of the first network slice. The first cell is the resident cell of the relay device. The first network slice is associated with the first protocol data unit (PDU) session established by the relay device. The data radio bearer (DRB) corresponding to the first PDU session is used to carry the data of the backhaul link. The backhaul link is the backhaul link for transmitting the data of the second PDU session of the first terminal device. The first terminal device is the terminal device accessing the relay device. The transceiver module 11 is configured to 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. The first core network device serves the first terminal device.

[0358] In another possible implementation manner, the processing module 12 is configured to determine that the first cell is outside the service area of the first network slice. The first cell is the resident cell of the relay device. The first network slice is associated with the first protocol data unit (PDU) session established by the relay device. The data radio bearer (DRB) corresponding to the first PDU session is used to carry the data of the backhaul link. The backhaul link is the backhaul link for transmitting the data of the second PDU session of the first terminal device. The first terminal device is the terminal device accessing the relay device. The processing module 12 is configured to determine that the DRB corresponding to the third PDU session is used to carry the data of the backhaul link, where the third PDU session is associated with the third network slice, and there are available resources in the first cell for the third network slice.

[0359] In another possible implementation, the processing module 12 is configured to determine that the first cell is outside the service area of the first network slice, where the first cell is the resident cell of the relay device, the first network slice is associated with the first protocol data unit (PDU) session established by the relay device, the data radio bearer (DRB) corresponding to the first PDU session 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, and the first terminal device is the terminal device accessing the relay device. The transceiver module 11 is configured to send a fourth indication message, where the fourth indication message 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 the information indicating the service area of the fourth network slice provided by the first core network device.

[0360] In another possible implementation, the processing module 12 is configured to set the identifier of the resident cell provided by the relay device for 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 the terminal device accessing the relay device.

[0361] Wherein, when the apparatus 10 is used to execute Figure 5 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S502, S504, S506, S507; the processing module 12 may be configured to execute the processing steps in the method, such as steps S503, S505, S508, and S510.

[0362] When the apparatus 10 is used to execute Figure 6 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps; S611, S614, S616; the processing module 12 may be configured to execute the processing steps in the method, such as step S510.

[0363] When the apparatus 10 is used to execute Figure 7 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S721, S724, S726; the processing module 12 may be configured to execute the processing steps in the method, such as step S510.

[0364] When the apparatus 10 is used to execute Figure 8 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S831, S833; the processing module 12 may be configured to execute the processing steps in the method, such as step S510.

[0365] When the apparatus 10 is used to execute Figure 9When the apparatus 10 is used to execute the method in [description], the transceiver module 11 can be used to execute the steps of receiving and transmitting information in the method, such as step S921; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0366] When the apparatus 10 is used to execute Figure 10 When the apparatus 10 is used to execute the method in [description], the transceiver module 11 can be used to execute the steps of receiving and transmitting information in the method, such as step S1031; the processing module 12 can be used to execute the processing steps in the method, such as step S510.

[0367] When the apparatus 10 is used to execute Figure 11 When the apparatus 10 is used to execute the method in [description], the transceiver module 11 can be used to execute the steps of receiving and transmitting 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.

[0368] It should be understood that the specific processes of each unit executing the above corresponding steps have been described in detail in the above method embodiments. For the sake of brevity, they will not be repeated here.

[0369] In another design, the apparatus 10 can 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.

[0370] The apparatus 10 can implement the steps or processes executed by the first core network device corresponding to the above method embodiment. Among them, the transceiver module 11 can be used to execute the operations related to receiving and transmitting of the first core network device in the above method embodiment, and the processing module 12 can be used to execute the operations related to processing of the first core network device in the above method embodiment.

[0371] In a possible implementation, the transceiver module 11 is used to receive the indication information for deactivating the second protocol data unit (PDU) session of the first terminal device. The processing module 12 is used to deactivate 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 the data of the backhaul link, 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 located outside the service area of the first network slice.

[0372] In another possible implementation, the transceiver module 11 is configured to receive indication information for updating the 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. The processing module 12 is configured to update the second service area information in response to the indication information, and the updated second service area information does not include the identifier of a second cell, where the second cell is a cell in which a relay device provides residence for the first terminal device. The transceiver module 11 is configured to send the updated second service area information to the first terminal device.

[0373] Wherein, when the apparatus 10 is used to execute Figure 5 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S01, S502, and S504; the processing module 12 may be configured to execute the processing steps in the method.

[0374] When the apparatus 10 is used to execute Figure 5 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S510 and S532; the processing module 12 may be configured to execute the processing steps in the method, such as steps S520, S521, S522, and S531.

[0375] When the apparatus 10 is used to execute Figure 6 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S612, S614, and S617; the processing module 12 may be configured to execute the processing steps S613, S615, and S618 in the method.

[0376] When the apparatus 10 is used to execute Figure 7 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S722, S724, and S727; the processing module 12 may be configured to execute the processing steps S723, S725, and S728 in the method.

[0377] When the apparatus 10 is used to execute Figure 9 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S921 and S923; the processing module 12 may be configured to execute the processing step S922 in the method.

[0378] When the apparatus 10 is used to execute Figure 10 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S1032 and S1034; the processing module 12 may be configured to execute the processing step S1033 in the method.

[0379] It should be understood that the specific processes for each unit to execute the above corresponding steps have been described in detail in the above method embodiments. For the sake of brevity, they will not be repeated here.

[0380] In another design, the device 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.

[0381] The device 10 may implement the steps or processes executed by the second core network device in the above method embodiment. Among them, the transceiver module 11 may be used to execute the operations related to the transceiver of the second core network device in the above method embodiment, and the processing module 12 may be used to execute the operations related to the processing of the second core network device in the above method embodiment.

[0382] In a possible implementation manner, the transceiver module 11 is configured to receive first indication information, where the first indication information includes 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. The transceiver module 11 is configured to send sixth indication information in response to the first indication information, where the sixth indication information is used to instruct the first core network device to deactivate 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 the data of the backhaul link, the backhaul link is the 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 located outside the service area of the first network slice.

[0383] In another possible implementation manner, the transceiver module 11 is configured to receive third indication information, where the third indication information is used to instruct to deactivate a first protocol data unit (PDU) session, and the data radio bearer (DRB) corresponding to the first PDU session 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 of a first terminal device, and the first terminal device is a terminal device accessing the relay device. The processing module 12 is configured to update the network slice associated with the first PDU session from a first network slice to a second network slice in response to the third indication information, where there are available resources in the second network slice in a 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, where the first message is used to indicate the second network slice associated with the first PDU session.

[0384] Among them, when the device 10 is used to execute Figure 5 the method in, the transceiver module 11 may be used to execute the steps of receiving and sending information in the method, such as steps S506 and S507; the processing module 12 may be used to execute the processing steps in the method.

[0385] When the device 10 is used to execute Figure 6 the method in, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S611 and S612; the processing module 12 can be used to execute the processing steps in the method.

[0386] When the device 10 is used to execute Figure 7 the method in, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S721 and S722; the processing module 12 can be used to execute the processing steps in the method.

[0387] When the device 10 is used to execute Figure 8 the method in, 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.

[0388] It should be understood that the specific processes for each unit to execute the above corresponding steps have been described in detail in the above method embodiments. For the sake of brevity, they will not be repeated here.

[0389] In another design, the device 10 can 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.

[0390] The device 10 can implement the steps or processes executed by the first terminal device corresponding to the above method embodiment. Among them, the transceiver module 11 can be used to execute the operations related to sending and receiving of the first terminal device in the above method embodiment, and the processing module 12 can be used to execute the operations related to processing of the first terminal device in the above method embodiment.

[0391] In a possible implementation, the transceiver module 11 is configured to receive first indication information, and the first indication information includes an identifier of a second protocol data unit (PDU) session. The transceiver module 11 is configured to send seventh indication information to a first core network device in response to the first indication information, and the seventh indication information includes the identifier of the second PDU session, and the seventh indication information is used to indicate deactivation of 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, the backhaul link is the 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.

[0392] In another possible implementation, the transceiver module 11 is configured to send fifth indication information for instructing a 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 a first terminal device. The transceiver module 11 is configured to receive the updated second service area information, and 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.

[0393] In yet another possible implementation, the transceiver module 11 is configured to receive eighth indication information for instructing that the second cell does not belong to a 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, where 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 second service area information provided by a 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.

[0394] Wherein, when the apparatus 10 is used to execute Figure 5 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as step S501; the processing module 12 may be configured to execute the processing steps in the method.

[0395] When the apparatus 10 is used to execute Figure 6 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps; S616, S617; the processing module 12 may be configured to execute the processing steps in the method.

[0396] When the apparatus 10 is used to execute Figure 7 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as steps S726, S727; the processing module 12 may be configured to execute the processing steps in the method.

[0397] When the apparatus 10 is used to execute Figure 9 the method in, the transceiver module 11 may be configured to execute the steps of sending and receiving information in the method, such as step S923; the processing module 12 may be configured to execute the processing steps in the method, such as step S924.

[0398] When the apparatus 10 is used to execute Figure 10When the apparatus 10 is used to execute the method in [description], 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.

[0399] When the apparatus 10 is used to execute Figure 11 When the apparatus 10 is used to execute the method in [description], 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.

[0400] It should be understood that the specific processes for each unit to execute the corresponding steps above have been described in detail in the above method embodiments. For the sake of brevity, they will not be repeated here.

[0401] It should also be understood that the apparatus 10 here is embodied in the form of functional modules. The term "module" here can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor, or a group of processors, etc.) for executing one or more software or firmware programs, and a memory, a combined logic circuit, and / or other suitable components that support the described functions. In an alternative example, those skilled in the art can understand that the apparatus 10 can specifically be the mobile management network element in the above embodiments and can be used to execute each process and / or step corresponding to the mobile management network element in the above method embodiments; or, the apparatus 10 can specifically be the terminal device in the above embodiments and can be used to execute each process and / or step corresponding to the terminal device in the above method embodiments. To avoid repetition, they will not be repeated here.

[0402] The apparatus 10 of each of the above solutions has the function of implementing the corresponding steps executed by the devices (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 method. This function can be implemented by hardware or by hardware executing the corresponding software. The hardware or software includes one or more modules corresponding to the above 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 execute the sending and receiving operations and related processing operations in each method embodiment.

[0403] In addition, the above transceiver module 11 can also be a transceiver circuit (for example, it can include a receiving circuit and a sending circuit), and the processing module can be a processing circuit.

[0404] Figure 13It is a schematic diagram of another communication device 20 provided by an embodiment of the present application. The device 20 includes a processor 21, and the processor 21 is configured to execute computer programs or instructions stored in a memory 22, or read data / signaling stored in the memory 22, so as to execute the methods in the above method embodiments. Optionally, the processor 21 is one or more.

[0405] Optionally, as Figure 13 shown, the device 20 further includes a memory 22, and the memory 22 is configured to store computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be separately provided. Optionally, the memory 22 is one or more.

[0406] Optionally, as Figure 13 shown, the device 20 further includes a transceiver 23, and the transceiver 23 is configured to receive and / or transmit signals. For example, the processor 21 is configured to control the transceiver 23 to receive and / or transmit signals.

[0407] As a solution, the device 20 is configured to implement the operations performed by the host access network device in the above method embodiments.

[0408] As another solution, the device 20 is configured to implement the operations performed by the relay device in the above method embodiments.

[0409] As yet another solution, the device 20 is configured to implement the operations performed by the first core network device in the above method embodiments.

[0410] As yet another solution, the device 20 is configured to implement the operations performed by the second core network device in the above method embodiments.

[0411] As yet another solution, the device 20 is configured to implement the operations performed by the first terminal device in the above method embodiments.

[0412] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0413] 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 ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, the RAM can be used as an external cache. By way of example and not limitation, the RAM includes the following various forms: static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0414] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, the memory (storage module) can be integrated in the processor.

[0415] It should also be noted that the memory described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0416] Figure 14 FIG. 10 is a schematic diagram of a chip system 30 provided by an embodiment of the present application. The chip system 30 (or may also be referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0417] Among them, the logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 can be coupled to the storage unit and call the instructions in the storage unit, so that the chip system 30 can implement the methods and functions of the embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, output the information processed by the chip system 30, or input the data or signaling information to be processed into the chip system 30 for processing.

[0418] As a solution, the chip system 30 is used to implement the operations performed by the host access network device, relay device, first core network device, second core network device, or first terminal device in the foregoing method embodiments.

[0419] For example, the logic circuit 31 is used to implement the operations related to the processing performed by the host access network device, relay device, first core network device, second core network device, or first terminal device in the foregoing method embodiments; the input / output interface 32 is used to implement the operations related to sending and / or receiving performed by the host access network device, relay device, first core network device, second core network device, or first terminal device in the foregoing method embodiments.

[0420] The embodiment of the present application further provides a computer-readable storage medium, on which computer instructions for implementing the methods performed by the host access network device, relay device, first core network device, second core network device, or first terminal device in the foregoing method embodiments are stored.

[0421] 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 the foregoing method embodiments.

[0422] The embodiment of the present application further provides a computer program product, including instructions, which when executed by a computer, 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 the foregoing method embodiments.

[0423] The embodiment of the present application further provides a communication system, including the foregoing host access network device, relay device, first core network device, and second core network device. Optionally, the communication system further includes the foregoing first terminal device.

[0424] The explanations and beneficial effects of the relevant content in any of the foregoing devices can be referred to the corresponding method embodiments provided above, and will not be elaborated here.

[0425] In several embodiments provided by the present 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 merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0426] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0427] Those skilled in the art can 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 foregoing method embodiments, and will not be repeated here.

[0428] In several embodiments provided by the present 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 illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0429] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0430] In addition, the functional units in each embodiment of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0431] When the above-mentioned 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 this application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0432] As described above, the above are only specific implementation manners of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A communication method, characterized in that, including: determine that a first cell is outside the service area of a first network slice, where the first cell is the resident cell of a relay device, the first network slice is associated with a first protocol data unit (PDU) session established by the relay device, a 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; send first indication information, where the first indication information is used to instruct a 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, wherein The determining that the first cell is outside the service area of the first network slice includes: determine that the first cell does not include resources allocated for the first network slice; or determine, according to the identifier of the first cell and the identifiers of at least one cell included in 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 a second core network device serving the relay device; or determine that the first PDU session is deactivated.

3. The method according to claim 1 or 2, characterized in that, The sending the first indication information includes: send the first indication information to a second core network device, where the first indication information includes the identifier of the first core network device, the identifier of the first terminal device, and the 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, where the second core network device serves the relay device.

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

5. The method according to claim 1 or 2, characterized in that, The sending the first indication information includes: send the first indication information to the first terminal device, where the first indication information includes 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.

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

8. A communication method, characterized in that, including: receive indication information for deactivating a second protocol data unit (PDU) session of a first terminal device; deactivate the second PDU session, where a data radio bearer (DRB) corresponding to a first PDU session established by a relay device is used to carry data of a backhaul link, 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.

9. The method according to claim 8, wherein Receiving the 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 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 includes: Sending second indication information for indicating the release of the resources configured for the second PDU session.

11. A communication method, characterized in that, including: Receiving third indication information for indicating the deactivation of a first protocol data unit (PDU) session, where the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a 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 Updating, in response to the third indication information, the network slice associated with the first PDU session from a first network slice to a second network slice, where there are available resources in the first cell for the second network slice, the first cell is the resident cell of the relay device, and the first cell is outside the service area of the first network slice; Sending a first message for indicating the second network slice associated with the first PDU session.

12. A communication method, characterized in that, including: Determining that the first cell is outside the service area of the first network slice, where the first cell is the resident cell of the relay device, the first network slice is associated with a first protocol data unit (PDU) session established by the relay device, the data radio bearer (DRB) corresponding to the first PDU session is used to carry data of a 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; Determining that the DRB corresponding to the 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 there are available resources in the first cell for the third network slice.

13. The method according to claim 12, wherein The determining that the first cell is outside the service area of the first network slice includes: Determining that the first cell does not include resources allocated for the first network slice; or, Determining, based on the identifier of the first cell and the identifiers 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 provided by the second core network device serving the relay device for indicating the service area of the first network slice; or, Determining that the first PDU session is deactivated.

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

15. The method according to claim 14, wherein The receiving the 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.

16. A communication method, characterized in that, Includes: Determine that the first cell is outside the service area of the first network slice, where the first cell is the cell where the relay device resides, the first network slice is associated with the first protocol data unit (PDU) session established by the relay device, the data radio bearer (DRB) corresponding to the first PDU session 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 of the first terminal device, and the first terminal device is the terminal device accessing the relay device; Send a fourth indication information, where 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 the information indicating the service area of the fourth network slice provided by the first core network device.

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

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

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

20. The method according to claim 19, wherein Before sending the fifth indication information, the method further includes: Receiving a 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 includes a processor and a memory, the processor is coupled to the memory, and the memory is used to store a computer program. When the processor runs the computer program, the communication device is caused to execute the method according to any one of claims 1-20.

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

23. A computer program product, characterized in that, It includes computer instructions. When the computer instructions run on a communication device, the communication device is caused to execute the method according to any one of claims 1-20.

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

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