COMMUNICATION METHOD, TERMINAL DEVICE, AND CORE NETWORK DEVICE

Abstract

The present application provides a communication method, a terminal device, and a core network device. The method includes: A terminal device in a first TA sends a first registration request message to a core network device; The terminal device receives a registration acceptance message from the core network device, where the registration acceptance message includes information about a rejected slice, information about a first registration area (RA), and first indication information, where the first indication information indicates that a second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to the rejected slice; When the terminal device moves from the first TA to the second TA, the terminal device sends a second registration request message to the core network device based on the first indication information, where the second registration request message includes information about the first slice. The requirement that the terminal device implements communication by using a network slice can be better met in the present application.

Description

[Technical field]

[0001] The present application relates to the field of communication technologies, and in particular to a communication method, a terminal device, and a core network device. [Background technology]

[0002] This application claims priority to Chinese Patent Application No. 202210329805.5, entitled “COMMUNICATION METHOD, TERMINAL DEVICE, AND CORE NETWORK DEVICE,” filed with the China State Intellectual Property Office on March 28, 2022, the entire contents of which are incorporated herein by reference.

[0003] The concept of network slices has been introduced into the fifth generation (5G) communication system. Using network slicing technology, one physical network can be divided into multiple virtual networks, where the virtual networks are regarded as "network slices", and the network slices are independent of each other. Different sessions in one terminal device may require respective network slices corresponding to the sessions for service provisioning.

[0004] In practical application, the terminal device includes the requested network slice in a request to register with the network, and obtains the authorized network slice and registration area from the network side after successfully registering with the network. The terminal device can access the authorized network slice in any tracking area in the registration area and use the services provided by the authorized network slice. However, for another slice (i.e., a rejected network slice) that is not included in the authorized network slice and is in the requested network slice, in the current registration area, the terminal device is not allowed to use the rejected network slice even if the terminal device is in a tracking area that supports the rejected network slice. This greatly limits the amount or type of network slices that can be used by the terminal device within the current network coverage range, and also limits the type of PDU session that can be established by the terminal device. As a result, the requirement that the terminal device implements communication by using a network slice cannot be met.

[0005] In this case, how to better meet the requirement that terminal devices perform communication by using network slices becomes a technical problem to be solved. Summary of the Invention

[0006] The embodiments of the present application provide a wireless communication method, a terminal device, and a core network device to better meet the requirement that a terminal device performs communication by using network slices.

[0007] According to a first aspect, a communication method is provided, including:

[0008] A terminal device in a first tracking area TA sends a first registration request message to a core network device.

[0009] The terminal device receives a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, wherein the first indication information indicates that the second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to a rejected slice.

[0010] When the terminal device moves from the first TA to the second TA, the terminal device sends a second registration request message to the core network device based on the first indication information, and the second registration request message includes information regarding the first slice.

[0011] When the terminal device moves from a first TA to a second TA, and the terminal device determines that the first slice needs to be accessed to establish a PDU session based on the current service requirements (e.g., APP usage requirements), the terminal device can know that the second TA in which the terminal device is currently located supports the first slice based on the indication of the first indication information. Since the first slice is a rejected slice in the current RA (first RA), the terminal device automatically triggers a registration procedure and sends a registration request message (i.e., a second registration request message) to the AMF again, and the requested slice carried in the second registration request message includes information about the first slice. After being approved by the AMF, the terminal device can access the first slice to perform communication.

[0012] According to the communication method provided in this embodiment of the present application, the registration acceptance message further carries first indication information, and the terminal device can know the TA in which the particular rejected slice is available based on the first indication information. For example, the terminal can know that the rejected first slice is actually available in the second TA based on the first indication information. In this way, after moving to the second TA, if the terminal device still wants to use the first slice to perform network communication (e.g., establishing a PDU session), the terminal device may initiate a registration request again to request access to the first slice. Based on the above settings, the amount or type of network slices that can be used by the terminal device within the current wireless network coverage range can be increased, and the type of PDU session that can be established by the terminal device can also be increased, thus satisfying the requirement of the terminal device to perform communication by using the network slice to a greater extent, thereby improving the user experience.

[0013] Regarding the first aspect, in some implementations of the first aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice.

[0014] With regard to the first aspect, in some implementations of the first aspect, the first indication information includes support information of multiple TAs for the rejected slice, where the support information indicates that each of the multiple TAs supports at least one slice in the rejected slice or indicates a slice in the rejected slice that is supported by each of the multiple TAs, where each of the multiple TAs belongs to a first RA, and where the multiple TAs include a second TA.

[0015] The advantage of the above configuration is that the information amount of the first indication information is increased, so that the terminal device can know that multiple rejected slices may be available in the second TA based on the first indication information. In this way, after moving to the second TA, if the terminal device wants to use at least one of the multiple rejected slices to perform communication, the terminal device may initiate a registration request again to request access to the corresponding slice. Thus, the amount or type of network slices that can be used by the terminal device within the current wireless network coverage range can be increased to a greater extent, and thus the requirement of the terminal device to perform communication by using network slices is met to a greater extent, thereby further improving the user experience.

[0016] Regarding the first aspect, in some implementations of the first aspect, before the terminal device receives a registration acceptance message from the core network device, the method further includes: the terminal device sends first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability of receiving the first indication information.

[0017] It is taken into consideration that the protocol releases implemented (supported) by the terminal device may be inconsistent. For example, some terminals implement a higher release protocol, some terminals implement a lower release protocol, and some release protocols may not support the terminal in receiving the first indication information. Therefore, in order to avoid problems such as reception errors and unrecognizable reception, the method provided in this embodiment of the present application further specifies that the terminal device sends the first capability indication information to the AMF in advance to indicate whether the terminal device has the capability to receive the first indication information. When the AMF determines that the terminal device has the capability to receive the first indication information, the registration acceptance message sent by the AMF to the terminal device carries the first indication information.

[0018] Optionally, the first capability indication information may be indicated explicitly (directly). For example, as a protocol or system specification, the first capability indication information is a string of a specific code, or a bit of 0 or 1, or is differentiated by using NULL and non-NULL. Alternatively, the first capability indication information may be indicated implicitly (indirectly). This is not limited in the present application.

[0019] For example, the first capability indication information may include one bit of 1 to indicate that the terminal device has the capability to receive the first indication information, and may use one bit of 0 to indicate that the terminal device does not have the capability to receive the first indication information.

[0020] Regarding the first aspect, in some implementations of the first aspect, the first capability indication information is carried in a first registration request message.

[0021] Optionally, the first capability indication information may alternatively be carried in another message in the prior art, or the terminal device may separately send the first capability indication information to the AMF, which is not limited in this application.

[0022] According to a second aspect, a communication method is provided, including: a terminal device in a first tracking area TA sends a first registration request message to a core network device.

[0023] The terminal device receives a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, the first indication information indicating that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, and the rejected slices include the first slice.

[0024] When the terminal device moves from the first TA to the second TA, the terminal device sends a second registration request message to the core network device based on the first indication information, and the second registration request message includes information regarding the first slice.

[0025] According to the method provided in this embodiment of the present application, the registration acceptance message further carries first indication information, which only indicates to the terminal device that the second TA may support one or more slices in the rejected slice, but does not explicitly indicate one specific slice or multiple specific slices supported by the second TA. After moving to the second TA, if the terminal device still wants to use the first slice to perform network communication (e.g., establishing a PDU session), the terminal device automatically triggers a registration procedure and sends a registration request message (i.e., a second registration request message) to the AMF again, and the requested slice carried in the second registration request message includes information about the first slice. After being approved by the AMF, the terminal device may access the first slice to perform communication. Based on the above settings, the amount or type of network slices that can be used by terminal devices within the current wireless network coverage range can be increased, and the types of PDU sessions that can be established by terminal devices can also be increased, thus satisfying to a greater extent the requirement for terminal devices to perform communication by using network slices, thereby improving user experience.

[0026] In addition, compared with the above embodiment, the method provided in this embodiment does not disclose the support information of the second TA for the rejected slice, and therefore can ensure that the slice deployment information of the operator is not disclosed to the terminal device, thereby achieving higher security performance. Of course, when the terminal device initiates a connection request for the first slice in the second TA by using the second registration request message, the connection request may be rejected because the second TA does not support the first slice.

[0027] Regarding the second aspect, in some implementations of the second aspect, the first indication information includes an identifier of the second TA.

[0028] With regard to the second aspect, in some implementations of the second aspect, the first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate a connection request for any slice in the rejected slice, and the TA set including an identifier of a second TA.

[0029] Regarding the second aspect, in some implementations of the second aspect, before the terminal device receives a registration acceptance message from the core network device, the method further includes: the terminal device sends first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability of receiving the first indication information.

[0030] Regarding the second aspect, in some implementations of the second aspect, the first capability indication information is carried in the first registration request message.

[0031] According to a third aspect, a communication method is provided, including: a terminal device in a first tracking area TA sends a first registration request message to a core network device.

[0032] The terminal device receives a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, wherein the first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG.

[0033] The terminal device receives information about the first NSASG via a broadcast message of the second TA in the first RA.

[0034] The terminal device camps on the second TA and sends a second registration request message to the core network device based on the first indication information, where the second registration request message includes information regarding the first slice.

[0035] According to the method provided in this embodiment of the present application, the registration acceptance message further carries first indication information, and the terminal device can know, based on the first indication information, about the NSASG corresponding to the TA in which the particular rejected slice is available. For example, the terminal can know, based on the first indication information, that the rejected first slice is actually available in the second TA corresponding to the first NSASG. When the terminal device receives information about the first NSASG through the broadcast message of the second TA, the terminal can know that the second TA can support the first slice. In this case, if the terminal device determines that the terminal device still wants to use the first slice to perform network communication (e.g., PDU session establishment), the terminal device may camp on the second TA and initiate a registration request again to request to access the first slice. Based on the above settings, the amount or type of network slices that can be used by terminal devices within the current wireless network coverage range can be increased, and the types of PDU sessions that can be established by terminal devices are also increased, thus satisfying to a greater extent the requirement for terminal devices to perform communication by using network slices, thereby improving user experience.

[0036] In addition, in this method, a specific TA slice deployment situation is not disclosed to the terminal device, and only the mapping relationship between the NSASG and the rejected slice is provided. When the NSASG broadcast information is obtained through detection, a request for the rejected slice may be triggered, and there is no need to handover to the corresponding TA for triggering. For example, in this case, the terminal device may only be located at the edge of the TA. This is more flexible and applicable to more scenarios.

[0037] Regarding the third aspect, in some implementations of the third aspect, the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0038] With regard to the third aspect, in some implementations of the third aspect, the first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0039] Regarding the third aspect, in some implementations of the third aspect, before the terminal device receives a registration acceptance message from the core network device, the method further includes: the terminal device sends first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability of receiving the first indication information.

[0040] Regarding the third aspect, in some implementations of the third aspect, the first capability indication information is carried in the first registration request message.

[0041] According to a fourth aspect, there is provided a communication method, including:

[0042] The core network device receives a first registration request message from the terminal device.

[0043] The core network device sends a registration acceptance message to the terminal device, and the registration acceptance message includes information about the rejected slice, a first registration area ( RA ) and first indication information.

[0044] The first indication information indicates that the second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to a rejected slice; or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG.

[0045] The core network device receives a second registration request message from the terminal device, where the second registration request message includes information regarding the first slice.

[0046] Regarding the fourth aspect, in some implementations of the fourth aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice, the first indication information includes an identifier of the second TA, or the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0047] Regarding the fourth aspect, in some implementations of the fourth aspect, the first indication information includes support information of a plurality of TAs for the rejected slice, and the support information indicates that each of the plurality of TAs supports at least one slice in the rejected slice, or indicates a slice in the rejected slice that is supported by each of the plurality of TAs, and each of the plurality of TAs belongs to a first RA, and the plurality of TAs includes a second TA, or The first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate a connection request for any slice in the rejected slice, and the TA set including an identifier of a second TA; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0048] Regarding the fourth aspect, in some implementations of the fourth aspect, the method further includes: the core network device receives first capability indication information from the terminal device, where the first capability indication information indicates that the terminal device has a capability of receiving the first indication information; the core network device sending a registration acceptance message to the terminal device includes: the core network device sends a registration acceptance message to the terminal device based on the first capability indication information.

[0049] Regarding the fourth aspect, in some implementations of the fourth aspect, the first capability indication information is carried in the first registration request message.

[0050] Regarding the fourth aspect, in some implementations of the fourth aspect, before the core network device sends a registration acceptance message to the terminal device, the method further includes:

[0051] The core network device determines that the second TA belongs to the first RA and supports at least one slice among the rejected slices.

[0052] According to a fifth aspect, there is provided a communication method, including:

[0053] The core network device receives a first registration request message from the terminal device.

[0054] The core network device obtains first capability indication information, where the first capability indication information indicates whether the terminal device has a capability to receive the first indication information.

[0055] When the first capability indication information indicates that the terminal device has the capability to receive the first indication information, the core network device sends a registration acceptance message to the terminal device, and the registration acceptance message includes information about the rejected slice, a first registration area, ( RA ) and first indication information. The first indication information includes information about a second tracking area. ( T.A. ) indicates that the first slice is supported and the second TA belongs to the first RA and the first slice belongs to a rejected slice, or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG.

[0056] When the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, the core network device sends a registration acceptance message to the terminal device, where the registration acceptance message includes information about the rejected slice and information about the second RA, and the TA in the second RA does not support the rejected slice.

[0057] Regarding the fifth aspect, in some implementations of the fifth aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice, or The first indication information includes an identifier of the second TA; or The first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0058] Regarding the fifth aspect, in some implementations of the fifth aspect, the first indication information includes support information of a plurality of TAs for the rejected slice, and the support information indicates that each of the plurality of TAs supports at least one slice in the rejected slice, or indicates a slice in the rejected slice that is supported by each of the plurality of TAs, and each of the plurality of TAs belongs to a first RA, and the plurality of TAs includes a second TA, or The first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate a connection request for any slice in the rejected slice, and the TA set including an identifier of a second TA; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0059] Regarding the fifth aspect, in some implementations of the fifth aspect, the first capability indication information is carried in the first registration request message.

[0060] According to a sixth aspect, there is provided a terminal device, comprising: A sending module configured to send a first registration request message to a core network device when the terminal device is in a first tracking area (TA); A receiving module configured to receive a registration acceptance message from a core network device, the registration acceptance message including information about a rejected slice, a first registration area, ( RA )and first indication information, the first indication information indicating that a second TA supports the first slice, the second TA belongs to a first RA, and the first slice belongs to a rejected slice. Includes.

[0061] The transmitting module is further configured to send a second registration request message to the core network device based on the first indication information when the terminal device moves from the first TA to the second TA, where the second registration request message includes information regarding the first slice.

[0062] Regarding the sixth aspect, in some implementations of the sixth aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice.

[0063] Regarding the sixth aspect, in some implementations of the sixth aspect, the first indication information includes support information of multiple TAs for the rejected slice, each of the multiple TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the multiple TAs.

[0064] With regard to the sixth aspect, in some implementations of the sixth aspect, before the receiving module receives a registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0065] Regarding the sixth aspect, in some implementations of the sixth aspect, the first capability indication information is carried in a first registration request message.

[0066] According to a seventh aspect, there is provided a terminal device, comprising: A sending module configured to send a first registration request message to a core network device when the terminal device is in a first tracking area (TA); A receiving module configured to receive a registration acceptance message from a core network device, the registration acceptance message including information about a rejected slice, a first registration area, ( RA ) a receiving module including information regarding the first slice among the rejected slices, and first indication information, the first indication information indicating that the terminal device is permitted to initiate a connection request for any slice among the rejected slices in a second TA, the second TA belonging to the first RA and supporting at least one slice among the rejected slices, and the rejected slices including the first slice; Includes.

[0067] The transmitting module is further configured to send a second registration request message to the core network device based on the first indication information when the terminal device moves from the first TA to the second TA, where the second registration request message includes information regarding the first slice.

[0068] Regarding the seventh aspect, in some implementations of the seventh aspect, the first indication information includes an identifier of the second TA.

[0069] With regard to the seventh aspect, in some implementations of the seventh aspect, the first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set.

[0070] With regard to the seventh aspect, in some implementations of the seventh aspect, before the receiving module receives a registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0071] Regarding the seventh aspect, in some implementations of the seventh aspect, the first capability indication information is carried in a first registration request message.

[0072] According to an eighth aspect, there is provided a terminal device, comprising: A sending module configured to send a first registration request message to a core network device when the terminal device is in a first tracking area (TA); A receiving module configured to receive a registration acceptance message from a core network device, the registration acceptance message including information about a rejected slice, a first registration area, ( RA ) a receiving module including information regarding the first slice and a first network slice access stratum group (NSASG), the first slice belongs to a rejected slice, and the first RA includes a second TA; and Includes.

[0073] The receiving module is further configured to receive information about the first NSASG via a broadcast message of the second TA.

[0074] The transmitting module is further configured to send a second registration request message to the core network device when the terminal device camps on the second TA based on the first indication information, where the second registration request message includes information regarding the first slice.

[0075] Regarding the eighth aspect, in some implementations of the eighth aspect, the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0076] With regard to the eighth aspect, in some implementations of the eighth aspect, the first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0077] With regard to the eighth aspect, in some implementations of the eighth aspect, before the receiving module receives a registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0078] Regarding the eighth aspect, in some implementations of the eighth aspect, the first capability indication information is carried in a first registration request message.

[0079] According to a ninth aspect, there is provided a core network device, comprising: a receiving module configured to receive a first registration request message from a terminal device; A sending module configured to send a registration acceptance message to a terminal device, the registration acceptance message including information about the rejected slice, a first registration area, ( RA ) a transmitting module including information regarding the first indication information; Includes.

[0080] The first indication information indicates that the second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to a rejected slice; or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA, supports at least one slice in the rejected slices, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG, the first slice belongs to the rejected slice, and the first RA includes the second TA.

[0081] The receiving module is further configured to receive a second registration request message from the terminal device, where the second registration request message includes information regarding the first slice.

[0082] With regard to the ninth aspect, in some implementations of the ninth aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice, the first indication information includes an identifier of the second TA, or the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0083] Regarding the ninth aspect, in some implementations of the ninth aspect, the first indication information includes support information of a plurality of TAs for the rejected slice, each of the plurality of TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the plurality of TAs or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0084] With regard to the ninth aspect, in some implementations of the ninth aspect, the receiving module is further configured to receive first capability indication information from the terminal device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0085] The sending module is specifically configured to send a registration acceptance message to the terminal device based on the first capability indication information.

[0086] With regard to the ninth aspect, in some implementations of the ninth aspect, the first capability indication information is carried in a first registration request message.

[0087] According to a tenth aspect, there is provided a core network device, comprising: A receiving module configured to receive a first registration request message from a terminal device, the first registration request message including first capability indication information, the first capability indication information indicating whether the terminal device has a capability to receive the first indication information; A sending module configured to send a registration acceptance message to the terminal device when the first capability indication information indicates that the terminal device has a capability to receive the first indication information, the registration acceptance message including information about a rejected slice, a first registration area, ( RA ) and a transmitting module including information regarding the second tracking area and a first indication information. The first indication information includes a second tracking area. ( T.A. ) indicates that the first slice is supported and the second TA belongs to the first RA and the first slice belongs to a rejected slice, or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA, supports at least one slice in the rejected slices, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG, the first slice belongs to the rejected slice, and the first RA includes the second TA.

[0088] When the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, the sending module is configured to send a registration acceptance message to the terminal device, the registration acceptance message including information regarding the rejected slice and information regarding a second RA, and the TA in the second RA does not support the rejected slice.

[0089] With regard to the tenth aspect, in some implementations of the tenth aspect, the first indication information includes an identifier of the second TA and an identifier of the first slice, the first indication information includes an identifier of the second TA, or the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0090] Regarding the tenth aspect, in some implementations of the tenth aspect, the first indication information includes support information of a plurality of TAs for the rejected slice, each of the plurality of TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the plurality of TAs or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0091] According to an eleventh aspect, an embodiment of the present application provides a communication device. The communication device may be a terminal device or a chip disposed in the terminal device. The communication device includes a processor, a memory, and a transceiver.

[0092] The transceiver is configured to receive and transmit messages.

[0093] The memory is configured to store instructions.

[0094] The processor is configured to execute instructions stored in the memory such that, when the processor executes the instructions stored in the memory, the communication device is enabled to perform a method embodied in any implementation of the first to third aspects.

[0095] According to a twelfth aspect, an embodiment of the present application provides a communication device. The communication device may be a core network device or a chip disposed in the core network device. The communication device includes a processor, a memory, and a transceiver.

[0096] The transceiver is configured to receive and send messages.

[0097] The memory is configured to store instructions.

[0098] The processor is configured to execute instructions stored in the memory, which, when executed by the processor, enables the communication device to perform a method embodied in any of the implementations of the fourth and fifth aspects.

[0099] According to a thirteenth aspect, there is provided a terminal device, comprising at least one processor, coupled to a memory and configured to read and execute instructions in the memory to implement a method embodied in any of the implementations of the first to third aspects.

[0100] Optionally, the terminal device further includes a memory.

[0101] According to a fourteenth aspect, there is provided a core network device, comprising at least one processor, coupled to a memory and configured to read and execute instructions in the memory to implement a method as embodied in any of the implementations of the fourth and fifth aspects.

[0102] Optionally, the core network device further comprises a memory.

[0103] According to a fifteenth aspect, there is provided a computer program product comprising computer program code which, when executed on a computer, enables the computer to perform a method as embodied in any of the implementations of the first to fifth aspects.

[0104] It should be noted that all or part of the computer program code may be stored in the first storage medium, which may be encapsulated together with the processor or may be encapsulated separately from the processor, which is not particularly limited in this application.

[0105] According to a sixteenth aspect, there is provided a computer readable medium. The computer readable medium stores a program code. When the computer program code is executed on a computer, the computer is enabled to perform a method as embodied in any of the implementations of the first to fifth aspects.

[0106] According to a seventeenth aspect, a chip system is provided, comprising a processor configured to call a computer program from a memory and execute the computer program to enable a communication device installed with the chip system to perform a method as implemented in an implementation of any of the first to fifth aspects.

[0107] According to an eighteenth aspect, there is provided a communication system, the communication system including at least one of the terminal device provided in the first to third aspects and the core network device provided in the fifth or fourth aspect. [Brief description of the drawings]

[0108] [Figure 1] 1 is a schematic diagram of the network architecture of a 5G communication system. [Diagram 2] FIG. 1 is a schematic diagram of an example network slice. [Diagram 3] FIG. 13 is a schematic diagram of a slice selection procedure of a terminal device in a registration process. [Figure 4] FIG. 1 is a schematic diagram of a possible application scenario according to the present application. [Diagram 5] 1 is a schematic flowchart of an example of a communication method according to an embodiment of the present application. [Figure 6] 4 is a schematic flowchart of another example of a communication method according to an embodiment of the present application. [Figure 7] 4 is a schematic flowchart of yet another example of a communication method according to an embodiment of the present application. [Figure 8] 4 is a schematic flowchart of yet another example of a communication method according to an embodiment of the present application. [Figure 9] 4 is a schematic flowchart of yet another example of a communication method according to an embodiment of the present application. [Figure 10] FIG. 2 is a schematic block diagram of a terminal device according to an embodiment of the present application; [Figure 11] FIG. 2 is a schematic diagram of the structure of a terminal device according to an embodiment of the present application; [Figure 12] FIG. 2 is a schematic block diagram of a core network device according to an embodiment of the present application; [Figure 13] FIG. 2 is a schematic diagram of the structure of a core network device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0109] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following further describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0110] The technical solutions in the embodiments of the present application may be applied to various communication systems, such as a global system for mobile communications (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD) system, a universal mobile telecommunications system (UMTS), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth generation (5G) communication system, a new radio access technology (NR), and future communication systems (e.g., a sixth generation (6G) communication system).

[0111] In this application, a 5G communication system is used as an example for explanation. Figure 1 is a schematic diagram of a network architecture of a 5G communication system. This figure shows some network elements in the 5G architecture. The network architecture includes a terminal device, an access network device, an access management network element, a network slice selection network element, a data management network element, and a network repository network element. The following briefly describes the functions of each of the devices or network elements.

[0112] The terminal device in this application is a device with wireless transceiver function, and may also be referred to as user equipment (UE). The terminal device may be deployed on the ground, on the water (e.g., on a ship), or in the air (e.g., on an airplane, balloon, or satellite), including indoor or outdoor devices, or handheld or vehicle-mounted devices. The terminal device may be a mobile phone, a pad, a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc.

[0113] The access network device in this application is a device that provides wireless communication functions to terminals, and may also be referred to as a radio access network (RAN) device. The access network device includes, but is not limited to, next-generation Node B (gNode B, gNB) in 5G, evolved Node B (eNB), radio network controller (RNC), Node B (Node B, NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved Node B or home Node B, HNB), baseband unit (BBU), transmitting and receiving point (TRP), transmission point (TP), mobile switching center, etc.

[0114] The access management network element is a control plane network element provided by an operator network, and is responsible for access control and mobility management when a terminal device accesses an operator network, including functions such as mobility state management, allocation of temporary user identifiers, and user authentication. In a 5G communication system, the access management network element may be an access and mobility management function (AMF) network element. In future communication systems, for example, 6G, the access management network element may still be an AMF network element or may have another name. This is not limited in this application.

[0115] The network slice selection network element may be configured to select an appropriate network slice for the service of the terminal. In a 5G communication system, the network slice selection network element may be a network slice selection function (NSSF) network element. In future communication systems, for example, in 6G, the network slice selection function may still be an NSSF network element or may have another name. This is not limited in the present application.

[0116] The data management network element is configured for generating authentication credentials, user identity handling (e.g., storing and managing persistent user identifiers), access control, subscription data management, etc. In a 5G communication system, the data management network element may be a unified data management (UDM) network element. In future communication systems, e.g., 6G, the data management network element may still be a UDM network element or may have another name. This is not limited in this application.

[0117] The network repository network element may be configured to provide network element discovery functionality and provide network element information corresponding to a network element type based on a request of another network element. The network repository network element may further be configured to provide network element management services such as network element registration, update, and deregistration and network element status subscription and push. In a 5G communication system, the network repository network element may be a network repository function (NRF) network element. In future communication systems, for example, 6G, the network repository network element may still be an NRF network element or may have another name. This is not limited in the present application.

[0118] A session management function (SMF) network element is mainly configured for session management, UE Internet Protocol (IP) address allocation and management, selectable user plane function, policy control, termination point of charging function interface, downlink data notification, etc. In an embodiment of the present application, the session management function network element may be configured to implement the functions of a session management network element.

[0119] The terminal device in the embodiment of the present application may be the UE in FIG. 1, and the access network device in the embodiment of the present application may be the RAN in FIG. 1. The access management network element in the embodiment of the present application may be the AMF network element shown in FIG. 1, or may be a network element having the function of an AMF network element in a future communication system. The network slice selection network element in the embodiment of the present application may be the NSSF network element shown in FIG. 1, or may be a network element having the function of an NSSF network element in a future communication system. The data management network element in the embodiment of the present application may be the UDM network element shown in FIG. 1, or may be a network element having the function of a UDM network element in a future communication system. The network repository network element in the embodiment of the present application may be the NRF network element shown in FIG. 1, or may be a network element having the function of an NRF network element in a future communication system. The session management function network element in the embodiment of the present application may be the SMF network element shown in FIG. 1, or may be a network element having the function of an SMF network element in a future communication system.

[0120] For ease of explanation, the present application will be described hereinafter by using an example in which the access management network element is an AMF network element, the network slice selection network element is an NSSF network element, the data management network element is a UDM network element, the network repository network element is an NRF network element, and the session management function network element is an SMF. Furthermore, the AMF network element is abbreviated as AMF, the NSSF network element is abbreviated as NSSF, the UDM network element is abbreviated as UDM, the NRF network element is abbreviated as NRF, the SMF network element is abbreviated as SMF, the terminal device is abbreviated as UE, and the access network device is abbreviated as RAN. Specifically, the AMF described hereinafter in the present application may be replaced with an access management network element, the NSSF may be replaced with a network slice selection network element, the UDM may be replaced with a data management network element, the NRF may be replaced with a network repository network element, the SMF may be replaced with a session management function network element, the RAN may be replaced with an access network device, and the UE may be replaced with a terminal device.

[0121] It should be noted that in the embodiments of the present application, "network slice" and "slice" are the same concept and mean the same content. One of the descriptions is used in various places, and the two descriptions may be interchangeable.

[0122] The embodiments of the present application may be applied to various communication systems that support network slicing, for example, 5G communication systems. The terms "system" and "network" may be interchanged. The system architecture described in the embodiments of the present application is intended to more clearly describe the technical solutions in the embodiments of the present application, and does not constitute any limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art may know that with the development of network architecture, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0123] The above describes some basic concepts and 5G network architecture in the embodiments of the present application. The following continues to describe the relevant contents of the embodiments of the present application.

[0124] In the 5G era, hundreds of billions of Internet of Things devices will access the network. Different types of application scenarios have different requirements for the network, and some even compete with each other. If a single network is used to provide services for different types of application scenarios, the network architecture will be extremely complex, and the network management efficiency and resource utilization efficiency will be low. Therefore, a network slicing technology is provided. In the 5G network slicing technology, network environments isolated from each other are provided for different application scenarios in a manner of virtualizing independent logical networks on the same network infrastructure, so that network functions and characteristics can be customized based on the respective requirements for different application scenarios, and the quality of service (QoS) requirements of different services can be effectively guaranteed. The purpose of 5G network slicing is to organically combine terminal devices, access network resources, core network resources, and network operation, maintenance, and management systems to provide complete networks that can be operated and maintained independently and isolated from each other for different business scenarios or service types.

[0125] FIG. 2 is a schematic diagram of a network slice. In a particular example, FIG. 2 includes three network slices: a critical machine type of communication (MTC) slice, a massive MTC slice, and a mobile broadband (MBB) slice. In FIG. 2, a terminal device corresponding to the critical MTC slice may include a vehicle, etc. A terminal device corresponding to the massive MTC slice may include some measurement meters, such as an electric meter or a gas meter. A terminal device corresponding to the MBB slice may include a mobile phone, a personal computer (PC), etc.

[0126] Various scenarios present different requirements for the 3rd generation partnership project (3GPP) ecosystem, such as charging, policy, security, mobility, etc. 3GPP emphasizes that network slices do not affect each other. For example, a large amount of bursty meter reading services should not affect normal mobile broadband services. To meet the multi-faceted requirements and slice isolation, relatively independent management, operation, and maintenance between services is required, and customized service functions and analysis capabilities need to be provided. Instances of different service types are deployed on different network slices, and different instances of the same service type may also be deployed on different network slices.

[0127] When network slices are deployed in a core network, a network slice selection process is triggered when a terminal device initially attaches to the network. The network slice selection process depends on one or more of the following parameters: user subscription data, local configuration information, roaming agreement, or operator policy. In the network slice selection process, the above parameters need to be comprehensively considered to select the optimal slice type for the terminal device.

[0128] When a terminal needs to access a network slice, the terminal may provide a requested network slice to the core network so that the core network selects a network slice instance for the terminal. The network slice requested by the terminal may be represented by a requested network slice selection assistance information (requested NSSAI). The requested NSSAI includes one or more single network slice selection assistance information (S-NSSAI), i.e., the NSSAI is a set of groups of S-NSSAI. Each of the S-NSSAI identifies one network slice type. Alternatively, it may be understood that the S-NSSAI identifies a network slice, or it may be understood that the S-NSSAI is an identification information of a network slice. In the description of this application, "multiple" means two or more, and may be, for example, three, four, or five.

[0129] A network slice is identified by using an S-NSSAI, which includes a slice type / service type (SST) and a slice differentiator (SD). The SST is for describing the characteristics of the slice in terms of characteristics and services, and indicates the features and services that the network is expected to provide. The SD may be used as supplementary information to the SST when a network slice instance (NSI) is selected. For example, when the SST indicates multiple NSIs, the SD may further differentiate these NSIs. Specifically, the SD is used as optional information to distinguish different network slices with the same SST characteristics.

[0130] In a 5G network, when a terminal device needs to use a network service, the terminal device needs to register with the network first. Figure 3 is a schematic diagram of a slice selection procedure of a terminal device in a registration process. As shown in Figure 3, the terminal device performs a slice request during registration, and the core network device feeds back to the terminal device the allowed slices (allowed NSSAIs) that can be used by the terminal device. Then, when implementing a service, the terminal device can select a slice only from the allowed slices to establish a packet data unit (PDU) session. The specific process is as follows:

[0131] Step 1: The UE sends a registration request message to the RAN, and the RAN receives the registration request message from the UE.

[0132] The registration request message carries a requested slice (requested NSSAI), where the requested slice is a network slice of a PDU session that the terminal device expects to establish. The requested slice indicates a network slice provided by the terminal device for the serving public land mobile network in the registration process. For example, the requested slice is a slice supported by the UE and determined by the UE during subscription. The requested slice may include one or more slices (S-NSSAI), where one S-NSSAI may identify one network slice.

[0133] Step 2: The RAN sends a registration request to the initial AMF, and the initial AMF receives a registration request message from the RAN.

[0134] Specifically, the RAN forwards a registration request message to the initial AMF. The registration request message is, for example, an N1 message. The N1 message may include information such as an N1 parameter, a registration message, access information of the terminal device, PDU session information, and a context request of the UE.

[0135] Step 3: The initial AMF sends a request to the UDM to obtain subscription information of the UE, where the subscription information includes information such as the subscription NSSAI of the UE.

[0136] Step 4: If the initial AMF cannot determine the slices allowed by the UE, the initial AMF requests slice selection from the NSSF and sends the UE's requested slices, the UE's subscribed slices, and the UE's location information to the NSSF.

[0137] Step 5: The NSSF determines the slices allowed by the UE. In addition, if the AMF needs to be handed over, the NSSF also needs to determine the target AMF. In this case, the NSSF sends information such as the allowed slices, the set / list of target AMFs, and the identification (ID) of the NRF corresponding to the target AMF to the initial AMF.

[0138] In this specification, allowed slices refer to slices that can be used by the UE in all tracking areas (TA) in the current registration area (RA). The allowed slices include at least one slice included in the requested slice.

[0139] Correspondingly, the core network device may further maintain a network slice that denies the UE access. This network slice may be referred to as a rejected slice (rejected NSSAI) and may include one or more slices (S-NSSAI). A slice in the rejected slice may be a network slice that is not supported by the current network or the current TA. Currently, the rejected slice is usually determined based on the requested slice carried in the registration request of the UE. When the UE requests to access a network slice, if the current network or the current TA does not support the network slice, the network slice is added to the rejected slice list.

[0140] A TA is a basic unit of location management in a communication system and includes one or more cells. A cell is an area covered by one radio access network device or a part of an area covered by a radio access network device. A TA may include cells included by multiple radio access network devices. When a terminal device in an idle state needs to be paged, the paging is implemented by using a paging message in the unit of the TA, and the paging message for one terminal device is sent in all cells in the TA. One cell belongs to only one TA.

[0141] One network slice may provide services for one or multiple TAs, and one TA may support one or multiple network slices. A TA may be identified by using a tracking area identifier (TAI) or a tracking area code (TAC). The TAI includes a mobile country code (MCC), a mobile network code (MNC), and a TAC.

[0142] An RA includes one or more TAs. For example, a terminal device does not need to perform a mobility registration update when moving in different TAs in the same RA. A mobility registration update needs to be performed only when the terminal device moves to a new TA and determines that the new TA does not belong to the RA.

[0143] Step 6: When the AMF needs to be handed over, the initial AMF queries the corresponding NRF for relevant information about the target AMF based on the NRF identifier sent by the NSSF.

[0144] Step 7a: The initial AMF sends an AMF relocation request message to the target AMF, where the relocation request message is to request to relocate (update) the AMF for the UE. The AMF relocation request message carries indication information of the allowed slices.

[0145] As an optional step, step 7a may be replaced with step 7b, as shown in Figure 3. In step 7b, the initial AMF may alternatively send an AMF relocation request message to the target AMF through the RAN. The AMF relocation request message also carries indication information of the allowed slices.

[0146] Step 8: The target AMF sends a registration accept message to the RAN, and the RAN receives the registration accept message from the target AMF. The registration accept message is to inform the UE that the registration request is accepted. The registration accept message includes related information such as allowed slices, RAs allocated to the UE, and rejected slices. For example, the target AMF sends the registration accept message to the RAN by using an N2 message.

[0147] After the AMF handover procedure is completed, the target AMF may allocate an RA to the UE based on the allowed slice. The AMF may inquire about the status of the network slices supported by each of the multiple surrounding TAs, and the AMF forms an RA for the UE by using the multiple TAs that support the allowed slices.

[0148] A specific example is used for illustration. Table 1 shows the support status of various TAs for a network slice. The NSSF determines that the allowed slices include only slice #1. In this case, the AMF may inquire about the status of the network slices supported by each of multiple surrounding TAs and form RA #1 by using three TAs (i.e., TA #1, TA #2, and TA #3) that support slice #1. RA #1 is a registration area allocated to the UE by the core network. However, since TA #4 does not support slice #1, TA #4 cannot be allocated to RA #1.

[0149] [Table 1]

[0150] Step 9: The RAN sends a registration acceptance message to the UE, and the UE receives the registration acceptance message from the RAN. Specifically, the RAN forwards the registration acceptance message to the UE.

[0151] Please note that, for the UE, the AMF may not normally be required to be handed over. In this case, step 6 and step 7 (including step 7a and step 7b) may be omitted. In an alternative step of step 8, the initial AMF may send a registration acceptance message to the RAN, and the RAN forwards the registration acceptance message to the UE.

[0152] According to the latest protocol advances, a terminal device may initiate a registration procedure to a core network in the following five scenarios:

[0153] (1) First registration of a terminal device to a 5G network.

[0154] (2) Mobility registration update, triggered when a terminal device moves to a tracking area (TA) outside its original registration area (RA).

[0155] (3) Updates caused by terminal device capability changes.

[0156] (4) Periodic registration updates for terminal devices in an inactive state.

[0157] (5) Emergency registration.

[0158] Based on the above description, the UE performs network slice selection only in the registration procedure, and the UE triggers the registration procedure only in the above five cases. Therefore, the UE can perform the allowed NSSAI slice selection only in some of the above scenarios.

[0159] Figure 4 is a schematic diagram of possible application scenarios according to the present application. According to the current protocol, the following scenarios may exist, as shown in Figure 4:

[0160] TA#1 supports slice#1, and TA#2 supports slice#1 and slice#2. In this specification, TA#1 supporting slice#1 may be understood as slice#1 being available in TA#1, and TA#2 supporting slice#1 and slice#2 may be understood as slice#1 and slice#2 being available in TA#2. A UE accesses a network in TA#1 and performs a registration procedure. The slices requested by the UE are slice#1 and slice#2. However, since TA#1 only supports slice#1, the allowed slice is slice#1 and the rejected slice is slice#2. When a core network allocates an RA to a UE, since TA#2 also supports slice#1, both TA#1 and TA#2 fall within RA#1, and RA#1 is a registration area allocated to a UE by a core network. RA#1 includes at least a plurality of TAs, including TA#1 and TA#2.

[0161] The UE moves in RA#1. When the UE moves from TA#1 to the range of TA#2, which also supports slice#2, slice#2 is still not accessed because in this case TA#2 falls within the range of RA#1 and the UE is not outside the range of RA#1 and does not reinitiate the registration procedure. In addition, the UE does not request to establish a session for slice#2 because the current slice#2 is a rejected slice. If the UE still wants to access slice#2, the UE needs to move to TA#3, which is outside RA#1 and supports slice#2. In this case, the UE can reinitiate the registration procedure and attempt to access slice#2.

[0162] In conclusion, when a requested slice includes multiple slices and an allowed slice sent by a core network device includes a part of a slice in the requested slice, the other part of the slice included in the requested slice of the terminal device is not in the allowed slice. In this way, even if the terminal device is in a TA that supports the use of the other part of the slice (i.e., the rejected slice), the terminal device is not allowed to use the other part of the slice. This significantly limits the amount or type of network slices that can be used by the terminal device within the current network coverage range, and also limits the type of PDU session that can be established by the terminal device. As a result, the requirement that the terminal device perform communication by using a network slice cannot be met.

[0163] In this case, how to better meet the requirement that terminal devices perform communication by using network slices becomes a technical problem to be solved.

[0164] Based on the above problems, embodiments of the present application provide a communication method, a terminal device, and a core network device that increase the amount or type of network slices that can be used by a terminal device within a current network coverage range, and also increase the type of PDU sessions that can be established by the terminal device, so that the requirement of the terminal device to perform communication by using network slices can be met to a greater extent, thereby improving the user experience.

[0165] In the embodiments of the present application, it may be understood that the terminal device and / or the core network device (e.g., AMF) may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples. In the embodiments of the present application, other operations or variations of various operations may be further performed. In addition, the steps may be performed in a sequence different from that presented in the embodiments of the present application, and it may not be necessary for all of the operations in the embodiments of the present application to be performed. The core network device may include only one core network element (e.g., AMF), or may include, for example, multiple core network elements (e.g., at least two of the above initial AMF, target AMF, and NSSF). This is not particularly limited in the present application.

[0166] The following describes the communication method provided in the embodiment of the present application with reference to the accompanying drawings. An example in which the core network device in the embodiment is an AMF is used for description. Figure 5 is a schematic flowchart of the communication method 500 according to the present application. The following describes the communication method 500 provided in this embodiment of the present application with reference to Figure 5. The method 500 includes the following steps:

[0167] Step 501: A terminal device in a first tracking area TA sends a first registration request message to the AMF, and the AMF receives the first registration request message from the terminal device.

[0168] The method 500 provided in this embodiment of the present application may be applied to a scenario in which a terminal device initiates a registration procedure to a core network. The condition for triggering the registration procedure by the terminal device may be any one of the above five conditions. For example, when the terminal device is in the original registration area ( RA )When the terminal device moves to another TA (i.e., the first TA), a mobility registration update is triggered. Therefore, a new registration procedure needs to be initiated to the core network. In this embodiment of the present application, the conditions for triggering the registration procedure by the terminal device are not limited to the above five conditions. With the continuous development of the 3GPP standard, the registration procedure may be triggered by any other conditions in the future.

[0169] A terminal device accesses a network through a cell in a first TA and performs a registration procedure. The terminal device may send a first registration request message to an AMF through a radio access network (RAN) device. In response, the AMF receives a registration request message through the radio access network device. The registration request message in this specification may alternatively have another name in the future. This is not limited in this embodiment of the present application.

[0170] The first registration request message includes information about a requested slice (requested NSSAI), and the requested slice may include multiple slices. In this case, the first registration request message may include identifiers (e.g., SST and SD) corresponding to the multiple slices. The first registration request message is, for example, an N1 message. Specifically, the terminal device may send the first registration request message to the AMF through an N1 interface.

[0171] Step 502: The AMF determines allowed slices (Allowed NSSAI) and rejected slices (Rejected NSSAI).

[0172] After receiving the first registration request message, the AMF performs slice selection for the terminal device. The AMF performs a comprehensive decision based on information such as the subscription data, the requested slice, the roaming agreement, and the local configuration of the terminal device to select an allowed slice and a rejected slice for the terminal device.

[0173] The AMF may determine a set including one or more slices in the requested slice as an allowed slice. Specifically, the allowed slice may be a subset or universal set of slices included in the requested slice. Based on this, the AMF may determine a set including the remaining slices in the requested slice as a rejected slice. For example, a slice in the requested slice that is not supported by the current TA (i.e., the first TA) may be determined as a rejected slice.

[0174] In order to more conveniently and efficiently describe the technical solution in the present application, in a specific example, Table 2 is a table of correspondence between various types of slices and specific slices. As shown in Table 2, a terminal device located in TA#1 (i.e., a first TA) sends a first registration request message to the AMF, and the first registration request message includes a requested slice, and the requested slice includes a total of three slices, namely slice#1, slice#2, and slice#3. The AMF determines that the TA#1 in which the terminal is currently located only supports slice#3 and does not support the other two slices. Therefore, the AMF determines that slice#3 is an allowed slice, and slice#1 and slice#2 together constitute a rejected slice. That is, both slice#1 and slice#2 are rejected slices.

[0175] [Table 2]

[0176] Step 503: The AMF selects the first registration area as the current RA of the terminal device based on the allowed slice. ( RA ) Allocate.

[0177] In particular, the AMF may allocate an RA to a terminal device based on the allowed slice. The AMF may inquire about the status of slices supported by each of a plurality of TAs around the first TA, and the AMF forms a first RA by using a plurality of TAs supporting at least one slice in the allowed slice, and allocates the first RA to the terminal device. In other words, each of the TAs in the first RA should support at least one slice in the allowed slice. In this specification, a TA supporting a slice may also be understood as the slice being available in the TA. A TA not supporting a slice may also be understood as the slice being unavailable in the TA.

[0178] A specific example is used for explanation. Table 2 also shows the support status of various TAs for slices obtained by the AMF through the inquiry. The AMF obtains seven TAs including TA#1 to TA#7 through the inquiry. TA#1 is the TA where the terminal initiates the registration request, i.e., TA#1 is the first TA. The AMF determines that the allowed slices include only slice#3. For TA#2 to TA#7 around TA#1 and obtained by the AMF through the inquiry, the TAs that support slice#3 are TA#2 to TA#5. Therefore, the AMF forms the first RA by using a total of five TAs, i.e., TA#1 to TA#5. However, since TA#6 and TA#7 do not support slice#3, TA#6 and TA#7 cannot be allocated to the first RA.

[0179] The amount of multiple TAs in the above example is only an example for illustration. In this application, the amount of TAs obtained through the inquiry by the AMF is not limited, and the amount of TAs included in the RA is also not limited. Optionally, the AMF may inquire the NSSF or another core network element about the TAs and related information about the network slices that can be used in the TAs.

[0180] Optionally, in another implementation, the AMF may not be able to complete steps 502 and 503 independently. In this case, the AMF may complete steps 502 and 503 by using network elements such as NSSF and UDM. For example, at least one of the above steps may be fully completed by the NSSF, and the NSSF may notify the AMF of the corresponding result. For details, see the above description of steps 4 and 5. The AMF, NSSF, and UDM completing slice selection together and allocating RA to the terminal device belongs to the prior art and will not be described again in detail in this specification.

[0181] For example, the AMF may further exchange information with the NSSF and obtain information about allowed and rejected slices from the NSSF. In this case, the decision network element is the NSSF, and the AMF may receive and forward the message.

[0182] Step 504: The AMF sends a registration acceptance message to the terminal device, and the terminal device receives the registration acceptance message from the AMF, where the registration acceptance message may include information about the allowed slices, information about the rejected slices, and information about the first RA.

[0183] The registration acceptance message is for responding to the first registration request message. After determining the allowed slices, the rejected slices, and the first RA, the AMF may include the above information in the registration acceptance message and send the registration acceptance message to the terminal device. The AMF may send the registration acceptance message to the terminal device through a radio access network (RAN) device. Correspondingly, the terminal device receives the registration acceptance message through the radio access network device. The registration acceptance message in this specification may alternatively have another name in the future. This is not limited to this embodiment of the present application. The registration acceptance message may be, for example, an N2 message. Specifically, the AMF may send the registration acceptance message to the terminal device through the N2 interface.

[0184] Optionally, the allowed slices may include one or more slices, and the registration accept message may include identification information of one or more slices. Based on the above example, the allowed slices may include slice #3, and a corresponding information element (or bit) of the registration accept message may carry an identifier of slice #3. For example, the identifier may be S-NSSAI.

[0185] Optionally, the rejected slices may include one or more slices, and the registration accept message may include identification information of one or more slices. Based on the above example, the rejected slices may include slice #1 and slice #2, and corresponding information elements (or bits) of the registration accept message may carry identifiers of slice #1 and slice #2. For example, the identifiers may be S-NSSAI.

[0186] Optionally, the first RA may include multiple TAs including the first TA, and the information about the first RA may include identification information of each of the multiple TAs included in the first RA. The identifier of the TA may be, for example, TAI or TAC. Based on the above example, the information about the first RA may include identifiers of TA#1 to TA#5. Specifically, corresponding information elements (or bits) of the registration acceptance message may carry the identifiers of TA#1 to TA#5.

[0187] Furthermore, as shown in FIG. 5, unlike the prior art, the registration acceptance message in this embodiment of the present application further carries first indication information, where the first indication information indicates that the second TA supports the first slice, the second TA is a TA in the first RA, and the first slice is a slice in the rejected slices.

[0188] Optionally, the first indication information may be determined and generated by the AMF, or may be determined and generated by the NSSF, which is not particularly limited in this application.

[0189] For example, the NSSF may determine and generate relevant information such as allowed slices, rejected slices, and a first RA, and the first indication information is generated by the AMF and added to the registration acceptance message.

[0190] Step 505: The terminal device continues to perform another registration procedure to complete the registration. In this case, the terminal device may establish a PDU session by using one or more slices in the allowed slices. Of course, if the terminal device does not currently have a service requirement, a slice in the allowed slice may not be used.

[0191] Step 506: When the terminal device moves from the first TA to the second TA, the terminal device may send a second registration request message to the AMF based on the first indication information, where the second registration request message includes information regarding the first slice.

[0192] In particular, when a terminal device moves from a first TA to a second TA, and the terminal device determines that a first slice needs to be accessed to establish a PDU session based on a current service requirement (e.g., an application (APP) usage requirement), the terminal device can know that the second TA in which the terminal device is currently located supports the first slice based on the indication of the first indication information. Since the first slice is a rejected slice in the current RA (first RA), the terminal device automatically triggers a registration procedure and sends a registration request message (i.e., a second registration request message) to the AMF again, and the requested slice carried in the second registration request message includes information about the first slice. After being approved by the AMF, the terminal device may access the first slice to perform communication. For example, the second registration request message includes an identifier of the first slice. For example, the identifier may be the S-NSSAI of the first slice.

[0193] According to the communication method 500 provided in this embodiment of the present application, the registration acceptance message further carries first indication information, and the terminal device can know the TA in which the particular rejected slice is available based on the first indication information. For example, the terminal can know that the rejected first slice is actually available in the second TA based on the first indication information. In this way, after moving to the second TA, if the terminal device still wants to use the first slice to perform network communication (e.g., establishing a PDU session), the terminal device may initiate a registration request again to request access to the first slice. Based on the above settings, the amount or type of network slices that can be used by the terminal device in the current wireless network coverage range can be increased, and the type of PDU session that can be established by the terminal device can also be increased, thus satisfying the requirement of the terminal device to perform communication by using the network slice to a greater extent, thereby improving the user experience.

[0194] In a specific example, as shown in Table 2, the first slice is slice #1 in Table 2, and the second TA is TA #2 in Table 2. The first indication information indicates to the terminal device that TA #2 supports slice #1, i.e., slice #1 is available in TA #2. After the terminal device moves from TA #1, where the first registration request message is sent, to TA #2 (the terminal device may camp on or pass through another TA during this period), if the terminal device still wants to access slice #1 due to service requirements, the terminal device may initiate a registration request again to request access to slice #1.

[0195] Optionally, when the terminal device moves from the first TA to the second TA, if the terminal device determines that the terminal device wants to access another slice in addition to the first slice, in this case, in addition to the first slice, the requested slice in the second registration request message may further include the other slice, which is not particularly limited in the present application.

[0196] Optionally, when the terminal device moves from the first TA to the second TA, if the terminal device determines that the terminal device does not currently need to access the first slice (if the terminal device does not want to use the first slice), the terminal device may not send a second registration request message to the AMF, i.e., in this case, the terminal device may not perform any action. Step 506 may be omitted.

[0197] It should be noted that the communication method 500 in this embodiment of the present application actually provides another condition that can trigger the terminal device to initiate a registration procedure to the core network. Specifically, in addition to the above five conditions, the communication method 500 provided in this embodiment of the present application can be used as a sixth condition for triggering a registration procedure by the terminal device. Based on this, for step 501 of the method 500, i.e., the terminal device sending a first registration request message to the AMF, may alternatively be a registration procedure automatically triggered by the terminal device based on the first indication information. Specifically, in step 501, if the terminal device wishes to use a rejected slice in a previous RA, and the terminal finds that the first TA in which the terminal is currently located supports the rejected slice, the terminal sends a first registration request message to request access to the rejected slice.

[0198] Optionally, the first indication information may be carried in the registration acceptance message as an independent information element, and the first indication information may include an identifier of the second TA and an identifier of the first slice.

[0199] For example, the identifier of the second TA may be a TAI or TAC of the second TA, and the identifier of the first slice may be an S-NSSAI of the first slice.

[0200] Optionally, the three pieces of information, i.e., the information about the rejected slice, the information about the first RA, and the first indication information, may be carried in the registration acceptance message as three independent information elements, or the two or three pieces of information may be carried in the same information element (the advantage is that it helps to reduce the size of the entire registration acceptance message). In other words, the two or three pieces of information may share one information element. The specific implementation of the registration acceptance message is not particularly limited in this application.

[0201] Optionally, the second TA may be any one of a plurality of TAs in the first RA that support at least one slice in the rejected slice. For example, as shown in Table 2, the second TA may be any one of TA#2, TA#3, and TA#5.

[0202] Optionally, the second TA may support only one slice in the rejected slices, in which case the first slice is the unique slice supported by the second TA.

[0203] For example, as shown in Table 2, the second TA may be TA#2, which supports only slice #1 among the rejected slices. In this case, the first slice is slice #1.

[0204] In another example, as shown in Table 2, the second TA may be TA#3, which supports only slice #2 among the rejected slices. In this case, the first slice is slice #2.

[0205] Optionally, the second TA may support multiple slices in the rejected slice, in which case the first slice may be any one of the multiple slices supported by the second TA.

[0206] For example, as shown in Table 2, the second TA may be TA#5, which supports slice #1 and slice #2 among the rejected slices. In this case, the first slice may be slice #1 or slice #2.

[0207] Optionally, when the second TA supports multiple slices among the rejected slices, the first indication information may indicate multiple slices or all slices (if the first slice is one of the slices) among the multiple slices supported by the second TA.

[0208] For example, the second TA may be TA#5, which supports slice #1 and slice #2 in the rejected slice. In this case, the first indication information may indicate that TA#5 supports slice #1 and slice #2.

[0209] The advantage of the above configuration is that the information amount of the first indication information is increased, so that the terminal device can know that multiple rejected slices may be available in the second TA based on the first indication information. In this way, after moving to the second TA, if the terminal device wants to use at least one of the multiple rejected slices to perform communication, the terminal device may initiate a registration request again to request access to the corresponding slice. Thus, the amount or type of network slices that can be used by the terminal device within the current wireless network coverage range can be increased to a greater extent, and thus the requirement of the terminal device to perform communication by using network slices is met to a greater extent, thereby further improving the user experience.

[0210] Optionally, the first indication information includes support information of multiple TAs for the rejected slice, each of the multiple TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the multiple TAs.

[0211] In other words, the first indication information has a larger amount of information and can simultaneously indicate the support status of multiple TAs for the rejected slice. For example, one of the TAs supports one specific slice or multiple specific slices, and another TA supports one specific slice or multiple specific slices. After the terminal device moves to one of the TAs, the terminal device may determine that one or multiple rejected slices supported by the TA need to be accessed based on the actual requirements, and then initiate a second registration request message to request access to the corresponding slice. The above setting greatly increases the probability and frequency of sending the second registration request message, i.e., the probability and frequency of sending an access request that is for the rejected slice is also greatly increased. Therefore, the amount or type of network slices that can be used by the terminal device within the current wireless network coverage range can be increased to a greater extent, and thus the requirement of the terminal device to implement communication by using network slices is met to a greater extent, thereby further improving the user experience.

[0212] Optionally, the first indication information further indicates that the third TA supports the second slice, the third TA belongs to the first RA, the second slice is one slice among the rejected slices, and the second slice and the first slice may be the same or different.

[0213] For example, as shown in Table 2, the second TA may be TA#2, which supports only slice #1 among the rejected slices. In this case, the first slice is slice #1. The third TA may be TA#5, which supports slice #1 and slice #2 among the rejected slices. In this case, the second slice may be slice #1 or slice #2.

[0214] Similarly, when the third TA supports multiple slices among the rejected slices, the first indication information may indicate multiple slices or all slices (if the second slice is one of the slices) among the multiple slices supported by the third TA.

[0215] Optionally, the first indication information includes support information of multiple TAs for the rejected slice, where the multiple TAs are all TAs that support at least one slice in the rejected slice and are in the first RA.

[0216] For example, as shown in Table 2, in the first RA, TA#2, TA#3, and TA#5 support at least one rejected slice, and the first indication information includes the support information of the three TAs for the rejected slice. Specifically, the first indication information may simultaneously indicate one or more slices supported by the three TAs.

[0217] Optionally, the first indication information includes support information of multiple TAs for the rejected slice, where the support information indicates that each of the multiple TAs supports at least one slice in the rejected slice, or indicates a slice in the rejected slice that is supported by each of the multiple TAs, where each of the multiple TAs belongs to a first RA, and where the multiple TAs include a second TA.

[0218] Optionally, the support information may include identifiers of multiple TAs and identifiers of multiple rejected slices. There is a mapping relationship between the identifiers of the multiple TAs and the identifiers of the multiple slices. Based on the support information, the rejected slices supported by each of the TAs and the TAs supporting each of the slices can be known.

[0219] In a possible specific implementation, the first indication information may be in the form of a mapping table, which includes a one-to-one correspondence between a number of specific TAs and rejected slices, and the mapping table is sent based on a specific time sequence, for example: TA#2: slice #1, TA#3: slice #2, and TA#5: slice #1 and slice #2, where TA is used as an index in this case, or Slice #1: TA#2 and TA#5, and slice #2: TA#3 and TA#5, where in this case slice is used as index.

[0220] Further, before step 504 in which the terminal device receives a registration acceptance message from the AMF, i.e., before the AMF sends a registration acceptance message to the terminal device, the method 500 further includes:

[0221] The terminal device sends first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information. The AMF sends a registration accept message to the terminal device based on the first capability indication information.

[0222] In particular, it is taken into consideration that the protocol releases implemented (supported) by the terminal device may be inconsistent. For example, some terminals implement a higher release protocol, some terminals implement a lower release protocol, and some release protocols may not support the terminal in receiving the first indication information. Therefore, in order to avoid problems such as reception errors and unrecognizable reception, the method 500 provided in this embodiment of the present application further specifies that the terminal device sends the first capability indication information to the AMF in advance to indicate whether the terminal device has the capability to receive the first indication information. When the AMF determines that the terminal device has the capability to receive the first indication information, the registration acceptance message sent by the AMF to the terminal device carries the first indication information.

[0223] Optionally, the first capability indication information may be indicated explicitly (directly). For example, as a protocol or system specification, the first capability indication information is a string of a specific code, or a bit of 0 or 1, or is differentiated by using NULL and non-NULL. Alternatively, the first capability indication information may be indicated implicitly (indirectly). This is not limited in the present application.

[0224] For example, the first capability indication information may include one bit of 1 to indicate that the terminal device has the capability to receive the first indication information, and may use one bit of 0 to indicate that the terminal device does not have the capability to receive the first indication information.

[0225] Further, the first capability indication information may be carried in the first registration request message.

[0226] Optionally, the first capability indication information may alternatively be carried in another message in the prior art, or the terminal device may separately send the first capability indication information to the AMF, which is not limited in this application.

[0227] Optionally, in a possible alternative manner, the AMF may alternatively obtain capability information of the terminal device from another core network element (e.g., NSSF) through a query, and determine whether the terminal device has the capability to receive the first indication information based on the capability information. In this case, the act of sending the first capability indication information to the AMF by the terminal device may be omitted.

[0228] Figure 6 is a schematic flowchart of a communication method 600 according to an embodiment of the present application. The embodiment shown in Figure 6 may be regarded as a variant of the embodiment shown in Figure 5. The communication method 600 provided in this embodiment of the present application will be described below with reference to Figure 6. The method 600 includes the following steps:

[0229] Step 601: A terminal device in a first tracking area TA sends a first registration request message to the AMF, where the first registration request message carries a requested slice.

[0230] Correspondingly, in step 601, the AMF receives a first registration request message from the terminal device.

[0231] Optionally, the first registration request message may further carry first capability indication information, where the first capability indication information indicates that the terminal device has the capability to receive the first indication information. In a subsequent step, the AMF may send a registration acceptance message to the terminal device based on the first capability indication information.

[0232] Step 602: The AMF determines the allowed slices and the rejected slices.

[0233] Step 603: The AMF selects the first registration area as the current RA of the terminal device based on the allowed slice. ( RA ) Allocate.

[0234] Step 604: The AMF sends a registration acceptance message to the terminal device, where the registration acceptance message includes information about the allowed slice, information about the rejected slice, information about the first RA, and first indication information.

[0235] In response, the terminal device receives a registration acceptance message from the AMF.

[0236] Step 605: The terminal device continues to perform another registration procedure to complete the registration.

[0237] Step 606: When the terminal device moves from the first TA to the second TA, the terminal device sends a second registration request message to the AMF based on the first indication information, where the second registration request message includes information (e.g., an identifier) ​​about the first slice.

[0238] In response, the AMF receives a second registration request message from the terminal device.

[0239] The above steps 601 to 606 may be understood with reference to steps 501 to 506 of method 500, and only the differences are described herein. In this embodiment of the present application, the main difference from the embodiment shown in Fig. 5 is that the content indicated by the first indication information in method 600 is different from that in method 500. As a result, the success rate of the terminal device requesting AMF to access the first slice by using the second registration request message is also different.

[0240] In particular, in this embodiment, the first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in a second TA, the second TA belongs to the first RA and supports at least one slice in the rejected slices, and the rejected slices include the first slice.

[0241] According to the method 600 provided in this embodiment of the present application, the registration acceptance message further carries first indication information, which only indicates to the terminal device that the second TA may support one or more slices in the rejected slice, but does not explicitly indicate one specific slice or multiple specific slices supported by the second TA. After moving to the second TA, if the terminal device still wants to use the first slice to perform network communication (e.g., establishing a PDU session), the terminal device automatically triggers a registration procedure and sends a registration request message (i.e., a second registration request message) to the AMF again, and the requested slice carried in the second registration request message includes information about the first slice. After being approved by the AMF, the terminal device may access the first slice to perform communication. Based on the above settings, the amount or type of network slices that can be used by terminal devices within the current wireless network coverage range can be increased, and the types of PDU sessions that can be established by terminal devices are also increased, thus satisfying to a greater extent the requirement for terminal devices to perform communication by using network slices, thereby improving user experience.

[0242] In addition, compared with the above embodiment, the method 600 provided in this embodiment does not disclose the support information of the second TA for the rejected slice, and therefore can ensure that the slice deployment information of the operator is not disclosed to the terminal device, thereby achieving higher security performance. Of course, when the terminal device initiates a connection request for the first slice in the second TA by using the second registration request message, the connection request may be rejected because the second TA does not support the first slice.

[0243] For example, the first TA is TA#1 in Table 2, and the second TA is TA#2, which supports slice #1 in the rejected slice. After moving from TA#1 to TA#2, the terminal device determines that the terminal device needs to access slice #1 (i.e., the first slice is slice #1). In this case, the terminal device may again initiate a registration request to request to access slice #1. Because the first slice (slice #1) requested by the terminal device is a slice supported by the second TA, the AMF may allow the terminal device to access the first slice.

[0244] In another example, the first TA is TA#1 in Table 2, and the second TA is TA#2, which supports slice#1 in the rejected slice. After moving from TA#1 to TA#2, the terminal device determines that the terminal device needs to access slice#2 (i.e., the first slice is slice#2). In this case, the terminal device may again initiate a registration request to request to access slice#2. Because the first slice (slice#2) requested by the terminal device is not supported by the second TA, the AMF may deny the terminal device's access to the first slice.

[0245] Optionally, the first indication information may be carried in the registration acceptance message as an independent information element, in which case the first indication information may include an identifier of the second TA, for example, a TAI or a TAC.

[0246] Optionally, the second TA may be any one of a plurality of TAs in the first RA that support at least one slice in the rejected slice. For example, as shown in Table 2, the second TA may be any one of TA#2, TA#3, and TA#5.

[0247] Optionally, the first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set or list, each of the TAs in the TA set or list supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set.

[0248] In other words, the first indication information may indicate that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in each of the multiple TAs, each of which supports at least one slice in the rejected slice. In this case, the first indication information may include identifiers of the multiple TAs.

[0249] For example, as shown in Table 2, if any one of TA#2, TA#3, and TA#5 supports at least one slice in the rejected slice, the TA set may include multiple or all of TA#2, TA#3, and TA#5. The first indication information may indicate that the terminal device can initiate a connection request for any slice in the rejected slice in TA#2 and TA#3 (in this case, the TA set includes TA#2 and TA#3). The first indication information may include identification information of TA#2 and TA#3.

[0250] Based on the above settings, when the terminal device moves to any one of the TAs, it may initiate a connection request for any slice in the rejected slices. Thus, the frequency of sending the second registration request message can be increased, and the amount or type of network slices that can be used by the terminal device within the current wireless network coverage range can be increased to a greater extent, and thus the requirement of the terminal device to carry out communication by using the network slice is met to a greater extent, thereby further improving the user experience.

[0251] Optionally, the first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate a connection request for any slice in the rejected slice, and the TA set including an identifier of a second TA.

[0252] Optionally, the TA set may be a set of all TAs in the first RA that support at least one slice in the rejected slice. For example, the TA set may include TA#2, TA#3, and TA#5 in Table 2.

[0253] In this case, before sending a registration accept message to the terminal device, the AMF may first determine a TA set. For example, a TA that supports at least one slice in the rejected slice and is in the first RA is put into the set. For example, a second TA may be determined to belong to the first RA and support at least one slice in the rejected slice, and therefore the second TA may be put into the set.

[0254] Figure 7 is a schematic flowchart of a communication method 700 according to an embodiment of the present application. The embodiment shown in Figure 7 may be regarded as a variant of the embodiment shown in Figure 5. The communication method 700 provided in this embodiment of the present application will be described below with reference to Figure 7. The method 700 includes the following steps:

[0255] Step 701: A terminal device in a first tracking area TA sends a first registration request message to the AMF, where the first registration request message carries a requested slice.

[0256] Correspondingly, in step 701, the AMF receives a first registration request message from the terminal device.

[0257] Optionally, the first registration request message may further carry first capability indication information, where the first capability indication information indicates that the terminal device has the capability to receive the first indication information. In a subsequent step, the AMF may send a registration acceptance message to the terminal device based on the first capability indication information.

[0258] Step 702: The AMF determines the allowed slices and the rejected slices.

[0259] Step 703: The AMF selects the first registration area as the current RA of the terminal device based on the allowed slice. ( RA ) Allocate.

[0260] Step 704: The AMF sends a registration acceptance message to the terminal device, where the registration acceptance message includes information about the allowed slice, information about the rejected slice, information about the first RA, and first indication information, where the first indication information indicates that there is a mapping relationship between the first slice and a first network slice access stratum group (NSASG), the first slice belongs to the rejected slice, and the first RA includes a second TA.

[0261] In response, the terminal device receives a registration acceptance message from the AMF.

[0262] Step 705: The terminal device continues to perform another registration procedure to complete the registration.

[0263] Step 707: The terminal device receives information about the first NSASG through a broadcast message of the second TA.

[0264] Step 706: The terminal device camps on a second TA and sends a second registration request message to the AMF based on the first indication information, where the second registration request message includes information about the first slice.

[0265] In response, the AMF receives a second registration request message from the terminal device.

[0266] The above steps 701 to 706 may be understood with reference to steps 501 to 506 of method 500, and only the differences will be described herein. In this embodiment of the present application, the main difference from the embodiment shown in Fig. 5 is that the content or form indicated by the first indication information in method 700 is different from that in method 500. In this embodiment, the first indication information indicates that there is a mapping relationship between the first slice and the first NSASG.

[0267] In particular, multiple slices may be mapped to one NSASG, and then information about the NSASG is carried in a message broadcast by the RAN air interface. A terminal device may obtain an NSASG corresponding to a current cell or TA through listening over the air interface. In other words, an NSASG is the granularity of a cell or TA. Since each cell belongs to only one TA, the relationship between an NSASG and a TA may be many-to-one or one-to-one.

[0268] The terminal device may inquire of the core network, or the core network may configure the correspondence between the NSASG and the slice. For example, if NSASG#1 corresponds to slice#1 and slice#2, the cell or TA that broadcasts NSASG#1 should support slice#1 and slice#2. However, the correspondence needs to be configured and updated by the core network, and the terminal device cannot know about the correspondence from the broadcast information.

[0269] In step 704, the AMF sends first indication information to the terminal device. The first indication information indicates that there is a mapping relationship between the first slice and the first NSASG, that is, the TA corresponding to the first NSASG supports the first slice. In addition, the first slice belongs to a rejected slice, and the first RA includes a second TA.

[0270] Optionally, in another possible implementation, the first slice may alternatively not belong to the rejected slices.

[0271] Optionally, in another possible implementation, the second TA may alternatively not belong to the first RA.

[0272] In step 707, the terminal device receives information about the first NSASG via a broadcast message of the second TA of the first RA. For example, the information about the first NSASG may be carried in a system information block (e.g., in system information block 1 (SIB 1)) in the broadcast message.

[0273] In step 706, the terminal device may receive information about the first NSASG and determine, based on the first indication information, that a second TA corresponding to the information about the first NSASG (i.e., the TA to which the information about the first NSASG is sent) can support the first slice. Thus, the terminal device may camp on the second TA (e.g., a cell in the second TA) and send a second registration request message to the AMF. The second registration request message includes information about the first slice. After being approved by the AMF, the terminal device may access the first slice to perform communication.

[0274] According to the method 700 provided in this embodiment of the present application, the registration acceptance message further carries first indication information, and the terminal device can know about the NSASG corresponding to the TA in which the particular rejected slice is available based on the first indication information. For example, the terminal can know that the rejected first slice is actually available in the second TA corresponding to the first NSASG based on the first indication information. When the terminal device receives information about the first NSASG through the broadcast message of the second TA, the terminal can know that the second TA can support the first slice. In this case, if the terminal device determines that the terminal device still wants to use the first slice to perform network communication (e.g., PDU session establishment), the terminal device may camp on the second TA and initiate a registration request again to request to access the first slice. Based on the above settings, the amount or type of network slices that can be used by terminal devices within the current wireless network coverage range can be increased, and the types of PDU sessions that can be established by terminal devices can also be increased, thus satisfying to a greater extent the requirement for terminal devices to perform communication by using network slices, thereby improving user experience.

[0275] In addition, in the method 700, a specific TA slice deployment status is not disclosed to the terminal device, and only a mapping relationship between the NSASG and the rejected slice is provided. When the NSASG broadcast information is obtained through detection, a request for the rejected slice may be triggered, and there is no need to handover to the corresponding TA for triggering. For example, in this case, the terminal device may only be located at the edge of the TA. This is more flexible and applicable to more scenarios.

[0276] Optionally, the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0277] Optionally, the first indication information may indicate that there is a mapping relationship between the first slice and multiple NSASGs including the first NSASG, i.e., the first slice corresponds to multiple NSASGs and the first NSASG may be any one of the multiple NSASGs. After receiving a message of any NSASG, the terminal device may camp on the corresponding TA and initiate a registration request again to request access to the first slice.

[0278] Optionally, the first indication information may indicate that there is a mapping relationship between a plurality of slices including the first slice and the first NSASG, i.e., the plurality of slices correspond to the first NSASG, and indicates that the TA corresponding to the first NSASG may support a plurality of slices. The first slice may be any one of the plurality of slices.

[0279] Optionally, the first indication information indicates a mapping relationship between a plurality of slices (e.g., all) in the rejected slices and the NSASG, and the first slice is any one of the plurality of slices.

[0280] The above setting significantly increases the probability and frequency of sending a second registration request message, i.e., the probability and frequency of sending an access request for a rejected slice is also significantly increased. Thus, the amount or type of network slices that can be used by a terminal device within a current wireless network coverage range can be increased to a greater extent, and thus the requirement that the terminal device performs communication by using a network slice is met to a greater extent, thereby further improving the user experience.

[0281] In a possible specific implementation, the first indication information may be in the form of a mapping table, which includes correspondence between a number of specific slices and a number of NSASGs, and the mapping table is sent based on a specific time sequence, for example, NSASG#1: slice#1 and slice#2 or slice#1: NSASG#1 and NSASG#2.

[0282] Further, before step 704 in which the terminal device receives a registration acceptance message from the AMF, i.e., before the AMF sends a registration acceptance message to the terminal device, the method 700 further includes:

[0283] The terminal device sends second capability indication information to the core network device, where the second capability indication information indicates that the terminal device has the capability to receive information related to the NSASG. The AMF sends a registration acceptance message to the terminal device based on the second capability indication information.

[0284] The method 700 provided in this embodiment of the present application further specifies that the terminal device sends second capability indication information to the AMF in advance to indicate whether the terminal device has the capability to receive information related to the NSASG. When the AMF determines that the terminal device has the capability to receive information related to the NSASG, the registration acceptance message sent by the AMF to the terminal device carries the first indication information.

[0285] Similarly, the second capability indication information may be indicated explicitly (directly). For example, as a protocol or system specification, the second capability indication information is a string of a specific code, or a bit of 0 or 1, or is differentiated by using NULL and non-NULL. Alternatively, the second capability indication information may be indicated implicitly (indirectly). This is not limited in the present application.

[0286] For example, the second capability indication information may include one bit of 1 to indicate that the terminal device has the capability to receive information related to the NSASG, and may use one bit of 0 to indicate that the terminal device does not have the capability to receive information related to the NSASG.

[0287] Further, the second capability indication information may be carried in the first registration request message.

[0288] Optionally, the second capability indication information may alternatively be carried in another message in the prior art. Alternatively, the terminal device may separately send the second capability indication information to the AMF, or may send the first capability indication information and the second capability indication information to the AMF after integrating and packaging the first capability indication information and the second capability indication information. This is not limited in the present application.

[0289] Optionally, in a possible alternative manner, the AMF may alternatively obtain capability information of the terminal device from another core network element (e.g., NSSF) through a query, and determine whether the terminal device has the capability to receive information on the NSASG based on the capability information. In this case, the act of sending the second capability indication information to the AMF by the terminal device may be omitted.

[0290] Figure 8 is a schematic flowchart of a communication method 800 according to an embodiment of the present application. The embodiment shown in Figure 8 may be regarded as a variant of the embodiment shown in Figure 5. The communication method 800 provided in this embodiment of the present application will be described below with reference to Figure 8. The method 800 includes the following steps:

[0291] Step 801: A terminal device in a first tracking area TA sends a first registration request message to the AMF, where the first registration request message carries a requested slice.

[0292] Correspondingly, in step 801, the AMF receives a first registration request message from the terminal device.

[0293] Optionally, the first registration request message may further carry first capability indication information, where the first capability indication information indicates that the terminal device has the capability to receive the first indication information. In a subsequent step, the AMF may send a registration acceptance message to the terminal device based on the first capability indication information.

[0294] Step 802: The AMF determines the allowed slices and the rejected slices.

[0295] Step 803: The AMF selects the first registration area as the current RA of the terminal device based on the allowed slice. ( RA ) Allocate.

[0296] Step 804: The AMF sends a registration acceptance message to the terminal device, where the registration acceptance message includes information about the allowed slice, information about the rejected slice, information about the first RA, and first indication information, where the first indication information indicates that the second TA supports the first slice, the second TA is a TA in the first RA, and the first slice is a slice in the rejected slice.

[0297] In response, the terminal device receives a registration acceptance message from the AMF.

[0298] Step 805: The terminal device continues to perform another registration procedure to complete the registration.

[0299] The above steps 801 to 805 may be understood with reference to steps 501 to 505 of the method 500, and only the differences will be described herein. In this embodiment of the present application, the main difference from the embodiment shown in Figure 5 is that in the method 500, when the terminal device moves from the first TA to the second TA, the terminal device sends a second registration request message to the AMF based on the first indication information, and the second registration request message includes information about the first slice. However, in this embodiment, the terminal device directly initiates a session establishment request and skips the registration procedure.

[0300] In particular, the method 800 further includes the following steps.

[0301] Step 806: When the terminal device is located in the second TA area supporting the first slice, if the terminal device still needs to access the first slice (which may be determined based on the requirements of the APP, etc.), the terminal device initiates a session establishment request based on the first indication information, and adds the first slice supported by the second TA to the session establishment request. The AMF does not reject the session establishment request of the terminal device based on the current TA of the terminal device and the slice status supported by the TA, and performs the session establishment procedure.

[0302] Step 807: The terminal device triggers a change of TA due to handover.

[0303] Step 808a: The terminal device enters an IDLE state and initiates a service request by receiving a paging message (pages all TAs in the first RA) or step 808b is performed.

[0304] Step 808b: The terminal device initiates a service request with the service requirements, where the service request carries information about sessions that need to be activated, etc.

[0305] Step 809: After finding that the handover procedure of the terminal device in step 807 triggers a change of TA, or after receiving a service request of the terminal, the AMF verifies the current TA of the terminal device and the slice information of the session of the terminal device. If there is a session in the current TA that does not support slicing, a session release procedure is triggered.

[0306] Step 810: Implement a PDU session release procedure.

[0307] Figure 9 is a schematic flowchart of a communication method 900 according to an embodiment of the present application. The embodiment shown in Figure 9 may be regarded as a variant of the embodiment shown in Figure 5. The communication method 900 provided in this embodiment of the present application will be described below with reference to Figure 9. The method 900 includes the following steps:

[0308] Step 901: A terminal device in a first tracking area TA sends a first registration request message to the AMF, where the first registration request message carries information regarding a requested slice and first capability indication information, and the first capability indication information indicates whether the terminal device has the capability to receive the first indication information in any one of the above embodiments.

[0309] Step 902: The AMF determines the allowed slices and the rejected slices.

[0310] Step 903: The AMF allocates the first RA or the second RA to the terminal device based on the allowed slice and the indication of the first capability indication information.

[0311] In particular, when the first capability indication information indicates that the terminal device has the capability to receive the first indication information, the AMF may allocate a first RA to the terminal device according to the method in step 503, step 603, or step 703, and at least one TA in the first RA may support at least one slice in the rejected slice. When the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, in this case, the AMF may allocate a second RA to the terminal device, and any TA in the second RA may not support the rejected slice. In the following, Table 3 is used as an example for explanation.

[0312] [Table 3]

[0313] In Table 3, the AMF determines that the allowed slices include only slice #3, and the rejected slices include slice #1 and slice #2. If the first capability indication information indicates that the terminal device has the capability to receive the first indication information, the first RA is allocated to the terminal device according to the method described in the above embodiment (for details, please refer to the description of step 503). In this case, the first RA includes a total of five TAs, i.e., TA #1 to TA #5. If the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, the second RA is allocated to the terminal device. Each of the TAs in the second RA should support slice #3. In addition to this, each of the TAs in the second RA should not support any rejected slices, i.e., cannot support slice #1 and slice #2. Therefore, compared with the first RA, TA#2, TA#3, and TA#5 should be excluded from the second RA, ie, the second RA only includes TA#1 and TA#4.

[0314] When the first capability indication information indicates that the terminal device has the capability to receive the first indication information, step 904a is performed.

[0315] Optionally, the AMF may obtain the first capability indication information in another manner. For example, the AMF may obtain the first capability indication information by using subscription information of the terminal device. The AMF may store the subscription information, or the AMF may obtain the subscription information (first capability indication information) from another network element, for example, an NSSF or a UDM. The manner in which the AMF obtains the first capability indication information is not particularly limited in this application.

[0316] In step 904a, the AMF sends a registration acceptance message to the terminal device, where the registration acceptance message includes information about the rejected slice, a first registration area ( RA ) and first indication information. The first indication information includes information about a second tracking area. ( T.A. ) indicates that the first slice is supported and the second TA belongs to the first RA and the first slice belongs to a rejected slice, or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA, supports at least one slice in the rejected slices, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG, the first slice belongs to the rejected slice, and the first RA includes the second TA.

[0317] Upon receiving the registration acceptance message including the first indication information, the terminal device may continue to send a second registration request message to the AMF according to the relevant steps in methods 500 to 800 above, where the second registration request message includes information regarding the first slice.

[0318] When the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, step 904b is performed.

[0319] In step 904b, the AMF sends a registration acceptance message to the terminal device, where the registration acceptance message includes information regarding the rejected slice and information regarding a second RA, and the TA in the second RA does not support the rejected slice.

[0320] In this case, when the terminal device receives a registration acceptance message that does not include the first indication information, and The first When the terminal device moves to the second TA, a mobility registration update may be triggered because the terminal device moves to a TA outside the original RA, since the second TA does not belong to the current RA. Therefore, a new registration procedure needs to be initiated towards the core network.

[0321] Above, the communication method in the embodiment of the present application is described in detail with reference to Figures 1 to 9. Hereinafter, the apparatus in the embodiment of the present application is described in detail with reference to Figures 10 to 13. It should be understood that the apparatus shown in Figures 10 to 13 can implement one or more steps in the method procedure shown in Figures 5 to 9. To avoid repetition, the details will not be described again in this specification.

[0322] 10 is a schematic block diagram of a terminal device 1000 according to an embodiment of the present application. As shown in FIG. 10, the terminal device 1000 includes a transmitting module 1010 and a receiving module 1020.

[0323] The sending module 1010 is configured to send a first registration request message to a core network device when the terminal device 1000 is in a first tracking area TA.

[0324] The receiving module 1020 is configured to receive a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, wherein the first indication information indicates that the second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to a rejected slice.

[0325] The transmitting module 1010 is further configured to send a second registration request message to the core network device based on the first indication information when the terminal device 1000 moves from the first TA to the second TA, where the second registration request message includes information regarding the first slice.

[0326] Optionally, the first indication information includes an identifier of the second TA and an identifier of the first slice.

[0327] Optionally, the first indication information includes support information of multiple TAs for the rejected slice, each of the multiple TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the multiple TAs.

[0328] Optionally, before the receiving module receives the registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0329] Optionally, the first capability indication information is carried in the first registration request message.

[0330] In another implementation, the sending module 1010 is configured to send a first registration request message to a core network device when the terminal device 1000 is in a first tracking area TA.

[0331] The receiving module 1020 is configured to receive a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, the first indication information indicating that the terminal device 1000 is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA and supports at least one slice in the rejected slices, and the rejected slices include the first slice.

[0332] The transmitting module 1010 is further configured to send a second registration request message to the core network device based on the first indication information when the terminal device 1000 moves from the first TA to the second TA, where the second registration request message includes information regarding the first slice.

[0333] Optionally, the first indication information includes an identifier of the second TA.

[0334] Optionally, the first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slices, and the second TA is any one of the TAs in the TA set.

[0335] Optionally, before the receiving module receives the registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0336] Optionally, the first capability indication information is carried in the first registration request message.

[0337] In another implementation,

[0338] The sending module 1010 is configured to send a first registration request message to a core network device when the terminal device 1000 is in a first tracking area TA.

[0339] The receiving module 1020 is configured to receive a registration acceptance message from the core network device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information, the first indication information indicating that there is a mapping relationship between the first slice and a first network slice access stratum group NSASG, the first slice belongs to a rejected slice, and the first RA includes a second TA.

[0340] The receiving module 1020 is further configured to receive information about the first NSASG via a broadcast message of the second TA.

[0341] The transmitting module 1010 is further configured to send a second registration request message to the core network device when the terminal device camps on the second TA based on the first indication information, where the second registration request message includes information regarding the first slice.

[0342] Optionally, the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0343] Optionally, the first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and the NSASG, and the first slice is any one of the plurality of slices.

[0344] Optionally, before the receiving module receives the registration acceptance message from the core network device, the transmitting module is further configured to send first capability indication information to the core network device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0345] Optionally, the first capability indication information is carried in the first registration request message.

[0346] In a possible implementation, the terminal device 1000 may be the terminal device 1100 in the following figure. The functions of the transmitting module 1010 and the receiving module 1020 may be implemented by using the transceiver 1101 (i.e., a combination of a control circuit and an antenna) of the terminal device. The structure of the terminal device 1100 in the embodiment of the present application will be described below with reference to FIG. 11.

[0347] FIG. 11 is a schematic diagram of the structure of a terminal device 1100 according to an embodiment of the present application. The terminal device 1100 may be used in the system shown in FIG. 1 and perform the functions of the terminal device (UE) in the above method embodiment. For ease of explanation, FIG. 11 only shows the main components of the terminal device. As shown in FIG. 11, the terminal device 1100 includes a processor 1102, a memory, a control circuit, an antenna, and an input / output device. The processor 1102 is mainly configured to process communication protocols and communication data, control the entire terminal device, execute software programs, and process data of the software programs, for example, configured to support the terminal device in performing the acts described in the above method embodiment. The memory is mainly configured to store software programs and data. The control circuit is mainly configured to perform conversion between baseband signals and radio frequency signals and process radio frequency signals. The combination of the control circuit and the antenna may also be referred to as a transceiver 1101, which is mainly configured to transmit and receive radio frequency signals in the form of electromagnetic waves. An input / output device, for example a touch screen, a display, or a keyboard, is primarily configured to receive data entered by a user and output data to the user.

[0348] After the terminal device is powered on, the processor 1102 can read the software program in the storage unit, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor 1102 outputs a baseband signal to the radio frequency circuit after performing baseband processing on the data to be sent. After performing radio frequency processing on the baseband signal, the radio frequency circuit sends the radio frequency signal in the form of electromagnetic waves through an antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

[0349] Those skilled in the art may understand that for ease of explanation, FIG. 11 shows only one memory and one processor. In an actual terminal device, there may be multiple processors and multiple memories. The memory may also be referred to as a storage medium, a storage device, etc. This is not limited in this embodiment of the present application.

[0350] In an optional implementation, the processor may include a baseband processor and a central processing unit. The baseband processor is mainly configured to process communication protocols and communication data. The central processing unit is mainly configured to control the entire terminal device, execute software programs, and process data of the software programs. The processor of FIG. 11 may integrate the functions of the baseband processor and the central processing unit. Those skilled in the art may understand that the baseband processor and the central processing unit may alternatively be independent processors and are interconnected by using a technology such as a bus. Those skilled in the art may understand that the terminal device may include multiple baseband processors to accommodate different network standards, and the terminal device may include multiple central processing units to improve the processing capabilities of the terminal device. The components of the terminal device may be connected through various buses. The baseband processor may also alternatively be represented as a baseband processing circuit or a baseband processing chip. The central processing unit may alternatively be represented as a central processing circuit or a central processing chip. The functions of processing communication protocols and communication data may be built into the processor or stored in the storage unit in the form of a software program. The processor executes the software program to implement the baseband processing functions.

[0351] 12 is a schematic block diagram of a core network device 1200 according to an embodiment of the present application. The core network device 1200 shown in FIG.

[0352] The receiving module 1210 is configured to receive a first registration request message from a terminal device.

[0353] The sending module 1220 is configured to send a registration acceptance message to the terminal device, the registration acceptance message including information about the rejected slice, a first registration area ( RA ) and first indication information.

[0354] The first indication information indicates that the second TA supports the first slice, the second TA belongs to the first RA, and the first slice belongs to a rejected slice; or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA, supports at least one slice in the rejected slices, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG, the first slice belongs to the rejected slice, and the first RA includes the second TA.

[0355] The receiving module 1210 is further configured to receive a second registration request message from the terminal device, where the second registration request message includes information regarding the first slice.

[0356] Optionally, the first indication information includes an identifier of the second TA and an identifier of the first slice, or the first indication information includes an identifier of the second TA, or the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0357] Optionally, the first indication information includes support information of a plurality of TAs for the rejected slice, each of the plurality of TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the plurality of TAs; The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0358] Optionally, the receiving module 1210 is further configured to receive first capability indication information from the terminal device, where the first capability indication information indicates that the terminal device has a capability to receive the first indication information.

[0359] The sending module 1220 is specifically configured to send a registration acceptance message to the terminal device based on the first capability indication information.

[0360] Optionally, the first capability indication information is carried in the first registration request message.

[0361] In another implementation,

[0362] The receiving module 1210 is configured to receive a first registration request message from a terminal device, the first registration request message including first capability indication information, where the first capability indication information indicates whether the terminal device has a capability to receive the first indication information.

[0363] The sending module 1220 is configured to send a registration acceptance message to the terminal device when the first capability indication information indicates that the terminal device has the capability to receive the first indication information, and the registration acceptance message includes information about the rejected slice, the first registration area, ( RA ) and first indication information. The first indication information includes information about a second tracking area. ( T.A. ) indicates that the first slice is supported and the second TA belongs to the first RA and the first slice belongs to a rejected slice, or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in the second TA, the second TA belongs to the first RA, supports at least one slice in the rejected slices, and the rejected slices include the first slice; or The first indication information indicates that there is a mapping relationship between the first slice and the first network slice access stratum group NSASG, the first slice belongs to the rejected slice, and the first RA includes the second TA.

[0364] When the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, the sending module is configured to send a registration acceptance message to the terminal device, the registration acceptance message including information regarding the rejected slice and information regarding a second RA, and the TA in the second RA does not support the rejected slice.

[0365] Optionally, the first indication information includes an identifier of the second TA and an identifier of the first slice, or the first indication information includes an identifier of the second TA, or the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

[0366] Optionally, the first indication information includes support information of a plurality of TAs for the rejected slice, each of the plurality of TAs belonging to the first RA and supporting at least one slice in the rejected slice, and the second TA is any one of the plurality of TAs; The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slice in any TA in the TA set, each of the TAs in the TA set supports at least one slice in the rejected slice, and the second TA is any one of the TAs in the TA set; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

[0367] Figure 13 is a schematic diagram of the structure of a core network device 1300 according to an embodiment of the present application. As shown in Figure 13, the core network device 1300 includes a processor 1310, a memory 1320, and a communication interface 1330. The memory 1320 stores instructions. The processor 1310 is configured to execute instructions in the memory 1320. When the instructions are executed, the processor 1310 is configured to implement the method provided in any one of the above method embodiments. The processor 1310 is further configured to control the communication interface 1330 to communicate with the outside.

[0368] Further, the processor 1310, the memory 1320, and the communication interface 1330 may communicate with each other through internal connection paths to transmit control and / or data signals.

[0369] Further, the memory 1320 may be integrated into the processor 1310 or may be located separately from the processor 1310 .

[0370] In particular, the core network device 1300 may be configured to perform steps in the communication methods of Figures 5 to 9. The core network device 1300 may include modules in Figure 12 configured to perform the communication methods described above. In addition, the modules in the core network device 1300 and other operations and / or functions described above are respectively used to implement corresponding procedures of the communication methods of Figures 5 to 9. The specific processes by which each of the modules performs the corresponding steps described above are described in detail in the method. For the sake of brevity, the details will not be described again herein.

[0371] It should be understood that the processor in this embodiment of the application may be a central processing unit (CPU), or the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0372] It should be further understood that the memory in this embodiment of the present application may be volatile or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM) and is used as an external cache. By way of example, rather than of limitation, many forms of random access memories (RAMs) can be used, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM).

[0373] According to the method provided in the embodiment of the present application, the present application further provides a computer program product. The computer program product includes a computer program code. When the computer program code is executed on a computer, the computer is enabled to perform the method in any one of the embodiments shown in Figures 5 to 9.

[0374] According to the method provided in the embodiment of the present application, the present application further provides a computer-readable medium. The computer-readable medium stores a program code. When the program code is executed on a computer, the computer is enabled to execute the method in any one of the embodiments shown in Figure 5 to Figure 9.

[0375] According to the method provided in the embodiment of the present application, the present application further provides a system, which includes one or more terminal devices described above, one or more access network devices, and one or more core network devices.

[0376] All or part of the above embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or part of the above embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded and executed on a computer, the procedures or functions according to the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or another programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (e.g., infrared, radio, and microwave) manner. The computer-readable storage medium may be any available medium accessible by a computer, or a data storage device such as a server or data center incorporating one or more available media. The usable media may be magnetic media (e.g., a floppy disk, hard disk drive, or magnetic tape), optical media (e.g., a DVD), or semiconductor media. The semiconductor media may be a solid state drive.

[0377] For ease of understanding, the following describes the nouns used in the process of describing the solutions in this application.

[0378] In the embodiment of the present application, "indication" may include direct indication and indirect indication, or may include explicit indication and implicit indication. Information indicated by using information (e.g., the above "indication information") is called information to be indicated. In a specific implementation process, the information to be indicated is indicated in multiple ways, for example, but not limited to, a way of directly indicating the information to be indicated, for example, by indicating the information to be indicated or an index of the information to be indicated. Alternatively, the information to be indicated may be indicated indirectly by indicating other information, and there is an association relationship between the other information and the information to be indicated. Alternatively, only a part of the information to be indicated may be indicated, and the other part of the information to be indicated is known or agreed upon in advance. For example, in order to reduce the indication overhead to a certain extent, a specific information may be indicated by using a pre-agreed (e.g., specified in a protocol) arrangement sequence of multiple pieces of information as an alternative.

[0379] In the embodiments of the present application, the terms "first", "second" and various numbers are merely for distinction to facilitate description and are not used to limit the scope of the embodiments of the present application. For example, the terms are used to distinguish different indication information.

[0380] The "communication protocol" in the embodiments of the present application may be a standard protocol in the communication field, for example, may include an LTE protocol, an NR protocol, and related protocols applied to future communication systems, which is not limited in the present application.

[0381] The term "and / or" in this specification only describes an association relationship to describe associated objects, and indicates that three relationships may exist. For example, A and / or B may represent three cases: only A exists, both A and B exist, and only B exists. In addition, the character " / " in this specification generally indicates an "or" relationship between associated objects.

[0382] In this application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following items (moieties)" or similar expressions refer to a single item (moiety) or any combination of these items, including any combination of multiple items (moieties). For example, at least one of a, b, or c may refer to a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c may be singular or plural.

[0383] The sequence numbers of the above processes do not mean the execution sequence in the embodiment of the present application. The execution sequence of the processes should be determined based on the functions and internal logic of the processes, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0384] Those skilled in the art may realize that the units and algorithm steps may be implemented by electronic hardware or a combination of computer software and electronic hardware in combination with the examples described in the embodiments disclosed herein. Whether a function is implemented by hardware or software depends on the design constraints of a specific application and technical solution. Those skilled in the art may use different methods to implement the functions described for each specific application, but the implementation should not be considered to go beyond the scope of this application.

[0385] For the sake of convenience and simplicity, those skilled in the art can clearly understand that the specific work processes of the above systems, devices and units should be referred to the corresponding processes in the above method embodiments, and the details will not be described again in this specification.

[0386] In some embodiments provided in the present application, it should be understood that the disclosed system, device, and method may be implemented in other manners. For example, the described device embodiment is only an example. For example, the division into units is only a logical functional division, and may be other divisions in actual implementation. For example, multiple units or components may be combined or incorporated into another system, or some features may be ignored or not implemented. In addition, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. Indirect couplings or communication connections between devices or units may be implemented in electrical, mechanical, or other forms.

[0387] The units described as separate parts may or may not be physically separate, and the parts shown as units may or may not be physical units, and may be located in one location or distributed over multiple network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the solutions of the embodiments.

[0388] In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit.

[0389] When a function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application essentially, or a part that contributes to the prior art, or a part of the technical solution may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method described in the embodiments of the present application. The above storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0390] The above description is merely a specific implementation of the present application and is not intended to limit the scope of protection of the present application. Any variations or replacements that are easily conceived by those skilled in the art within the technical scope disclosed in this application shall fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. 1. A communication method comprising: sending a first registration request message by a terminal device in a first tracking area (TA) to a core network device; receiving, by the terminal device, a registration acceptance message from the core network device, the registration acceptance message including information about a rejected slice, information about a first registration area (RA), and first indication information, the first indication information indicating that a second TA supports a first slice, the second TA belongs to the first RA, and the first slice belongs to the rejected slice; sending a second registration request message to the core network device based on the first indication information when the terminal device moves from the first TA to the second TA, the second registration request message including information about the first slice; A communication method comprising:

2. The communication method of claim 1 , wherein the first indication information includes an identifier of the second TA and an identifier of the first slice.

3. 3. The communication method according to claim 1, wherein the first indication information includes support information of a plurality of TAs for the rejected slice, the support information indicating that each of the plurality of TAs supports at least one slice in the rejected slice, or indicating a slice in the rejected slice that is supported by each of the plurality of TAs, each of the plurality of TAs belonging to the first RA, and the plurality of TAs including the second TA.

4. Prior to the step of receiving, by the terminal device, a registration acceptance message from the core network device, the method further comprises: The method further includes sending, by the terminal device, first capability indication information to the core network device, the first capability indication information indicating that the terminal device has a capability to receive the first indication information. A communication method according to any one of claims 1 to 3.

5. The communication method of claim 4 , wherein the first capability indication information is carried in the first registration request message.

6. 1. A communication method comprising: sending a first registration request message by a terminal device in a first tracking area (TA) to a core network device; receiving, by the terminal device, a registration acceptance message from the core network device, the registration acceptance message including information about a rejected slice, information about a first registration area (RA), and first indication information, the first indication information indicating that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in a second TA, and the rejected slices include a first slice; sending a second registration request message to the core network device based on the first indication information when the terminal device moves from the first TA to the second TA, the second registration request message including information about the first slice; A communication method comprising:

7. The method of claim 6 , wherein the first indication information includes an identifier of the second TA.

8. The communication method according to claim 6 or 7, wherein the first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate the connection request for any slice in the rejected slice, and the TA set including the identifier of the second TA.

9. Prior to the step of receiving, by the terminal device, a registration acceptance message from the core network device, the method further comprises: The method further includes sending, by the terminal device, first capability indication information to the core network device, the first capability indication information indicating that the terminal device has a capability to receive the first indication information. A communication method according to any one of claims 6 to 8.

10. The communication method of claim 9 , wherein the first capability indication information is carried in the first registration request message.

11. 1. A communication method comprising: sending a first registration request message by a terminal device in a first tracking area (TA) to a core network device; receiving, by the terminal device, a registration acceptance message from the core network device, the registration acceptance message including information about a rejected slice, information about a first registration area RA, and first indication information, the first indication information indicating that there is a mapping relationship between the first slice and a first network slice access stratum group NSASG; receiving, by the terminal device, information regarding the first NSASG via a broadcast message of a second TA in the first RA; camping on the second TA by the terminal device and sending a second registration request message to the core network device based on the first indication information, the second registration request message including information about the first slice; A communication method comprising:

12. The communication method of claim 11 , wherein the first indication information includes an identifier of the first slice and an identifier of the first NSASG.

13. The communication method according to claim 11 or 12, wherein the first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is any one of the plurality of slices.

14. Prior to the step of receiving, by the terminal device, a registration acceptance message from the core network device, the method further comprises: The method further includes sending, by the terminal device, first capability indication information to the core network device, the first capability indication information indicating that the terminal device has a capability to receive the first indication information. A communication method according to any one of claims 11 to 13.

15. The method of claim 14 , wherein the first capability indication information is carried in the first registration request message.

16. 1. A communication method comprising: receiving, by a core network device, a first registration request message from a terminal device; sending a registration acceptance message by the core network device to the terminal device, the registration acceptance message including information about a rejected slice, information about a first registration area (RA), and first indication information; The first indication information indicates that a second TA supports a first slice, the second TA belongs to the first RA, and the first slice belongs to the rejected slice; or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in a second TA, and the rejected slices include a first slice; or The first indication information indicates that there is a mapping relationship between a first slice and a first network slice access stratum group (NSASG); Steps and receiving, by the core network device, a second registration request message from the terminal device, the second registration request message including information about the first slice; A communication method comprising:

17. the first indication information includes an identifier of the second TA and an identifier of the first slice; or the first indication information includes an identifier of the second TA; or The first indication information includes an identifier of the first slice and an identifier of the first NSASG.

17. The communication method according to claim 16.

18. The first indication information includes support information of a plurality of TAs for the rejected slice, the support information indicating that each of the plurality of TAs supports at least one slice in the rejected slice, or indicating a slice in the rejected slice that is supported by each of the plurality of TAs, each of the plurality of TAs belonging to the first RA, and the plurality of TAs including the second TA; or The first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate the connection request for any slice in the rejected slice, and the TA set including the identifier of the second TA; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is one of the plurality of slices.

18. A communication method according to claim 16 or 17.

19. The method comprises: The method further includes receiving, by the core network device, first capability indication information from the terminal device, the first capability indication information indicating that the terminal device has a capability to receive the first indication information; The step of sending a registration acceptance message to the terminal device by the core network device includes: sending, by the core network device, the registration acceptance message to the terminal device based on the first capability indication information; 19. A communication method according to any one of claims 16 to 18, comprising:

20. 20. The method of claim 19, wherein the first capability indication information is carried in the first registration request message.

21. Prior to the step of sending, by the core network device, a registration acceptance message to the terminal device, the method further comprises: determining, by the core network device, that the second TA belongs to the first RA and supports the at least one slice in the rejected slices; 20. The communication method according to claim 16, further comprising:

22. 1. A communication method comprising: receiving, by a core network device, a first registration request message from a terminal device; acquiring, by the core network device, first capability indication information, the first capability indication information indicating whether the terminal device has a capability to receive the first indication information; sending a registration acceptance message by the core network device to the terminal device when the first capability indication information indicates that the terminal device has the capability to receive the first indication information, the registration acceptance message including information on a rejected slice, information on a first registration area (RA), and the first indication information, the first indication information indicating that a second tracking area (TA) supports a first slice, the second TA belongs to the first RA, and the first slice belongs to the rejected slice; or The first indication information indicates that the terminal device is permitted to initiate a connection request for any slice in the rejected slices in a second TA, and the rejected slices include a first slice; or The first indication information indicates that there is a mapping relationship between a first slice and a first network slice access stratum group (NSASG); Step, or sending, by the core network device, a registration acceptance message to the terminal device when the first capability indication information indicates that the terminal device does not have the capability to receive the first indication information, the registration acceptance message including information on a rejected slice and information on a second RA, and a TA in the second RA does not support the rejected slice; A communication method comprising:

23. the first indication information includes an identifier of the second TA and an identifier of the first slice; or the first indication information includes an identifier of the second TA; or The first indication information includes an identifier of the first slice and an identifier of the first NSASG.

23. The communication method of claim 22.

24. The first indication information includes support information of a plurality of TAs for the rejected slice, the support information indicating that each of the plurality of TAs supports at least one slice in the rejected slice, or indicating a slice in the rejected slice that is supported by each of the plurality of TAs, each of the plurality of TAs belonging to the first RA, and the plurality of TAs including the second TA; or The first indication information includes a TA set, the TA set including an identifier of a TA in which the terminal device is permitted to initiate the connection request for any slice in the rejected slice, and the TA set including the identifier of the second TA; or The first indication information indicates a mapping relationship between a plurality of slices in the rejected slice and an NSASG, and the first slice is one of the plurality of slices.

24. A communication method according to claim 22 or 23.

25. 25. The method of claim 22, wherein the first capability indication information is carried in the first registration request message.

26. 16. A terminal device comprising at least one processor, coupled to a memory and configured to read and execute instructions in the memory to implement the method of any one of claims 1 to 15.

27. 25. A core network device comprising at least one processor coupled to a memory and configured to read and execute instructions in the memory to implement a method according to any one of claims 16 to 24.

28. 25. A computer readable storage medium, the computer readable storage medium storing a computer program, the computer program being enabled, when run on a computer, to perform the method according to any one of claims 1 to 24.

29. 25. A computer program product comprising computer program code, which, when executed on a computer, enables the computer to carry out a method according to any one of claims 1 to 24.

30. A communication system comprising a terminal device according to claim 26 and / or a core network device according to claim 27.

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