METHOD AND DEVICE FOR SLICE-BASED COMMUNICATIONS

Abstract

A method and device for slice-based communications are disclosed. The method includes: sending (201), by an amf node, a first request message to an nssf node; and receiving (202), by the amf node, a reply message from the nssf node, and obtaining (203), based on the reply message, allowed nssai network slice selection assistance information from a terminal device and corresponding allowed nssai service area information. The amf node obtains the allowed nssai network slice selection assistance information from the terminal device and the corresponding allowed nssai service area information from the nssf node, to avoid repeated interaction between the amf node and the nssf node after a change in the registration area caused by the terminal device moving. Therefore, this improves signaling exchange and processing efficiency and reduces system overhead.

Description

1 / 77 “SLICE-BASED COMMUNICATIONS METHOD AND DEVICE” TECHNICAL FIELD

[001] The embodiments of the present invention belong to the field of communication technologies and, in particular, to a method and device for slice-based communications. FUNDAMENTALS

[002] A network slice is a network architecture provided in a fifth-generation (5G) mobile communication system to respond to different user requirements, and a network and management can be customized to better meet the specific requirements of each consumer and business service. Support for a network slice is an important part of a next-generation architecture.

[003] A 5G network supports a deployment scenario as follows: a multi-slice single-user equipment (UE) scenario in which a UE can simultaneously access a plurality of slice instances of a network core. The plurality of slice instances share some network functions, including an Access and Mobility Management Function (AMF). In this scenario, an access network node needs to select an appropriate AMF based on Network Slice Selection Assistance Information (NSSAI) supported by an AMF and NSSAI requested by the UE.

[004] NSSAI include configured NSSAI and permitted NSSAI. Configured NSSAI and permitted NSSAI are stored in the UE. Configured NSSAI are the default NSSAI configured in the UE. Permitted NSSAI are the NSSAI that are returned by a PLMN to the UE after the PLMN accepts a connection request from the UE and that are left over from the network. The UE carries the permitted NSSAI in a subsequent network access process. A Radio Access Network (RAN) node selects an AMF based on the configured NSSAI from the permitted NSSAI carried by the UE.

[005] An NSSF is a function independent of the AMF, and can select a group of slice instances for the UE when the UE initially accesses a network. Currently, when an AMF node Petition 870240046306, dated 05 / 31 / 2024, p. 19 / 101 2 / 77 selects a slice for the UE by querying slice information through the use of an NSSF node. The NSSF node provides slice information held in a UE registration area. Therefore, an AMF determines, for the UE, slice selection assistance information also held in the UE registration area. The slice selection assistance information is used by a RAN to select an appropriate AMF for the UE in a subsequent NAS process. After the UE moves and performs a tracking area update (TAU) process, the UE registration area changes. The slice information held by a network may change in a new registration area. In other words, a slice that can provide a service to the UE also changes.In this case, previously determined slice selection assistance information cannot be used, the RAN cannot select an appropriate AMF for the UE based on the slice selection assistance information, and the AMF needs to query, from the NSSF node again, for network-supported slice information in the new registration area, and determine, for the UE, slice selection assistance information supported in the new registration area. As a result, the AMF node performs repeated queries or blind selection, and the AMF and NSSF interact repeatedly with each other, causing additional signaling and overhead in a system. SUMMARY

[006] The embodiments of the present invention provide a slice-based communications method and device to avoid querying again for slice information supported by a network in a new registration area, and to reduce system overheads when a slice providing a service to the UE changes.

[007] According to a first aspect, a slice-based communications method is provided. The method includes: To send, via an AMF node, an initial request message to an NSSF node; and to receive, via the AMF node, a response message from the NSSF node, and to obtain, based on the response message, the permitted NSSAI of a terminal device and service area information corresponding to the permitted NSSAI.

[008] The AMF node obtains selection assistance information. Petition 870240046306, dated 05 / 31 / 2024, p. 20 / 101 3 / 77 of the allowed NSSAI network slice from the terminal device and the corresponding service area information allowed from the NSSF node, to avoid repeated interaction between the AMF node and the NSSF node after a change in a register area caused by the terminal device moving. Therefore, this improves signaling exchange and processing efficiency and reduces system overhead.

[009] With reference to the first aspect, in a first possible implementation of the first aspect, the obtaining, by the AMF node based on the response message, of permitted NSSAI from a terminal device and service area information corresponding to the permitted NSSAI includes: when the response message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI, obtaining, by the AMF node, the permitted NSSAI and the service area information corresponding to the permitted NSSAI from the response message; or when the response message carries the permitted NSSAI, obtaining, by the AMF node, the permitted NSSAI from the response message, and obtaining, based on a match between the NSSAI and a service area, the service area information corresponding to the permitted NSSAI;or when the ported response message first carries the NSSAI and service area information corresponding to the first NSSAI, determining, by the AMF node based on the first NSSAI and the service area information corresponding to the first NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[010] The AMF node can obtain the allowed NSSAI from the terminal device and the allowed NSSAI service area information in different diversified ways based on different contents carried by the response message, thereby reducing the number of times the allowed NSSAI are repeatedly requested and system overhead.

[011] With reference to the first aspect or the first possible implementation of the first aspect, in a second possible implementation of the first aspect, when the response message carries the permitted NSSAI, obtained by the AMF node based on a Petition 870240046306, dated 05 / 31 / 2024, p. 21 / 101 4 / 77 matching between NSSAI and an NSSAI service area, the permitted NSSAI and the service area information corresponding to the permitted NSSAI additionally include: obtaining, via the AMF node, the matching between the NSSAI and a service area from the NSSF node.

[012] After obtaining the match between the NSSAI and a service area, it can be avoided that the match between the NSSAI and a service area is obtained every time a terminal device registration request is received, thereby reducing system overheads.

[013] With reference to the first aspect or to either the first possible implementation or the second possible implementation of the first aspect, in a third possible implementation of the first aspect, the method additionally includes: querying, by the AMF node, terminal device signature information, where the signature information includes terminal device signed NSSAI, the first request message carrying the first NSSAI and the first NSSAI are associated with the signed NSSAI.

[014] The AMF node queries the terminal device's subscription information. The first NSSAIs are associated with the subscribed NSSAIs, to ensure that a service provided to the terminal device by a network meets a subscription request.

[015] With reference to the first aspect or any of the first possible implementation to the third possible implementation of the first aspect, in a fourth possible implementation of the first aspect, the method additionally includes: receiving, by the AMF node, a registration request message from the terminal device, where the registration request message carries the configured NSSAI, the first request message carries the first NSSAI and the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[016] The AMF node receives the registration request message from the terminal device. The configured NSSAIs ported by the registration request message are associated with the first NSSAIs, to ensure that the network provides a service to the terminal device based on a requirement. Petition 870240046306, dated 05 / 31 / 2024, p. 22 / 101 5 / 77 actual of the terminal device.

[017] With reference to the first aspect or any of the first possible implementation to the fourth possible implementation of the first aspect, in a fifth possible implementation of the first aspect, the first request message carries the terminal device identification information.

[018] The first request message carries the terminal device identification information, so that the NSSF node can autonomously query the terminal device signature information, to support a scenario where the AMF node cannot obtain the terminal device signature information when there is a slice isolation requirement.

[019] With reference to the first aspect or any of the first possible implementation to the fifth possible implementation of the first aspect, in a sixth possible implementation of the first aspect, the response message additionally includes slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI.

[020] The AMF node can additionally obtain the slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI, so that when the network deploys a plurality of slice instances based on the same S-NSSAI, the AMF node can obtain a correct slice instance and a network function on the slice instance based on the NSSAI requested by the endpoint device, to provide a service to the endpoint device.

[021] With reference to the first aspect or any of the first possible implementation to the sixth possible implementation of the first aspect, in a seventh possible implementation of the first aspect, the method additionally includes: obtaining, by the AMF node, the registration area information of the terminal device; and determining, by the AMF node based on the permitted NSSAIs of the terminal device and the service area information corresponding to the permitted NSSAIs that are obtained and the registration area information of the terminal device, assigning information of a slice instance corresponding to each S-NSSAI in the permitted NSSAIs, where the attribute information is used to indicate whether a service area of Petition 870240046306, dated 05 / 31 / 2024, p. 23 / 101 6 / 77 instance of the slice corresponding to S-NSSAI includes a terminal device registration area.

[022] Based on the information from the terminal device's registration area, the AMF node can determine whether the service area of ​​the slice instance corresponding to each S-NSSAI in the allowed NSSAI includes the terminal device's registration area, to ensure that an appropriate target AMF node can be selected for the terminal device.

[023] With reference to the first aspect or the seventh possible implementation of the first aspect, in an eighth possible implementation of the first aspect, the first S-NSSAI is the S-NSSAI that is among the allowed NSSAIs and that corresponds to a service area that includes the terminal device registration area, and the method additionally includes: sending, via the AMF node, a second request message to an NRF device, where the second request message includes the first S-NSSAI or slice instance identification information corresponding to the first S-NSSAI; receiving, via the AMF, address information from a target AMF node from the NRF device; and sending, via the AMF, the allowed NSSAIs and the service area information corresponding to the allowed NSSAIs to the target AMF node based on the address information of the target AMF node.

[024] The AMF node determines, through the use of the NRF device, the target AMF node that serves the terminal device, and sends the allowed NSSAI and the service area information corresponding to the allowed NSSAI that is obtained to the target AMF node, so that the target AMF node selects an appropriate slice instance after receiving a session configuration request from the terminal device.

[025] With reference to the first aspect or the eighth possible implementation of the first aspect, in a ninth possible implementation of the first aspect, the method additionally includes: sending, via AMF, the slice instance identification information corresponding to each SNSSAI in the NSSAI allowed for the target AMF node.

[026] The AMF node determines, through the use of the NRF device, the target AMF node that serves the terminal device, and sends the slice instance identification information corresponding to each SPetition 870240046306, dated 05 / 31 / 2024, page 24 / 101 7 / 77 NSSAI instances are enabled for the target AMF node, so that the target AMF node selects an appropriate slice instance after receiving a session configuration request from the endpoint device.

[027] With reference to the first aspect or the eighth possible implementation of the first aspect, in a tenth possible implementation of the first aspect, the method additionally includes: sending, via the AMF node, the attribute information to the target AMF node.

[028] The AMF node determines, through the use of the NRF device, the target AMF node that serves the terminal device, and sends the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAI to the target AMF node, so that the target AMF node selects an appropriate slice instance after receiving a session configuration request from the terminal device.

[029] With reference to the first aspect or any of the first possible implementation to the tenth possible implementation of the first aspect, in an eleventh possible implementation of the first aspect, the permitted NSSAIs are the NSSAIs of a visited public land mobile network (VPLMN), and the reply message additionally includes the NSSAIs of a home public land mobile network (HPLMN) that correspond to the NSSAIs of the VPLMN, or the reply message additionally includes the NSSAIs of an HPLMN that correspond to the NSSAIs of the VPLMN, and the slice instance identification information corresponding to each S-NSSAI in the NSSAIs of the HPLMN.

[030] According to a second aspect, a slice-based communications method is provided. The method includes: To receive, via an NSSF node, an initial access request message from the AMF node; and to send, via the NSSF node, a response message to the AMF node, where the response message carries the NSSAI, or the NSSAI and the service area information corresponding to the NSSAI.

[031] The NSSF node sends the NSSAI, or the NSSAI and the service area information corresponding to the NSSAI, to the AMF node by using the reply message. This can avoid repeated interaction between the node of Petition 870240046306, dated 05 / 31 / 2024, p. 25 / 101 8 / 77 AMF and the NSSF node improve signal exchange and processing efficiency, and reduce system overhead.

[032] With reference to the second aspect, in a first possible implementation of the second aspect, the NSSAI are the permitted NSSAI.

[033] The NSSF node can directly send the permitted NSSAI, so that the AMF node can directly obtain the permitted NSSAI from a terminal device, thereby reducing the signaling overhead of the AMF node.

[034] With reference to the second aspect or the first possible implementation of the second aspect, in a second possible implementation of the second aspect, the first ported request message first the NSSAI and the allowed NSSAI are associated with the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[035] The first NSSAIs carried by the first request message are obtained by the AMF node by querying terminal device signature information and using the association between the first NSSAI and the signed NSSAI. This can increase the amount of NSSAI that can be supported by the terminal device.

[036] With reference to the second aspect or the first possible implementation of the second aspect, in a third possible implementation of the second aspect, the first request message carries the terminal device identification information, and the method additionally includes: querying, by the NSSF node, the terminal device signature information based on the identification information, where the signature information includes the terminal device's signed NSSAI and the allowed NSSAI are associated with the signed NSSAI.

[037] When the first request message carries the terminal device identification information, the NSSF node queries the terminal device's signature information. The first NSSAI are associated with the signed NSSAI, so that the amount of NSSAI that can be sustained by the terminal device can be increased. Petition 870240046306, dated 05 / 31 / 2024, p. 26 / 101 9 / 77

[038] With reference to the second aspect, in a fourth possible implementation of the second aspect, the first request message carries the first NSSAI, and the NSSAI are the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[039] The first NSSAIs carried by the first request message are obtained by the AMF node by querying terminal device signature information and using the association between the first NSSAI and the signed NSSAI. This can increase the amount of NSSAI that can be supported by the terminal device.

[040] With reference to the second aspect or the fourth possible implementation of the second aspect, in a fifth possible implementation of the second aspect, the first request message carries the terminal device identification information, and the method additionally includes: querying, by the NSSF node, the terminal device signature information based on the identification information, where the signature information includes the terminal device's signed NSSAI and the first NSSAI are associated with the signed NSSAI.

[041] When the first request message carries the terminal device identification information, the NSSF node queries the terminal device's signature information. The first NSSAI are associated with the signed NSSAI, so that the amount of NSSAI that can be sustained by the terminal device can be increased.

[042] With reference to the second aspect or any of the second possible implementation to the fifth possible implementation of the first aspect and the first possible implementation to the fifth possible implementation of the second aspect, in a sixth possible implementation of the second aspect, the terminal device signature information additionally includes a terminal device type, and the first request message additionally includes the terminal device type.

[043] The first request message carries the terminal device identification information, so that the NSSF node can autonomously query the terminal subscription information. This reduces Petition 870240046306, dated 05 / 31 / 2024, p. 27 / 101 10 / 77 is the number of times the AMF node queries the subscription information and system overheads.

[044] With reference to the second aspect or any of the first possible implementation to the sixth possible implementation of the second aspect, in a seventh possible implementation of the second aspect, the reply message additionally carries the slice instance identification information corresponding to each S-NSSAI in the NSSAI.

[045] The reply message carries the slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI, thereby avoiding repeated interaction between the AMF node and the NSSF node and reducing signaling overheads.

[046] With reference to the second aspect or any of the first possible implementation to the seventh possible implementation of the second aspect, in an eighth possible implementation of the second aspect, the NSSAI are the NSSAI of a VPLMN, and the reply message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, or the reply message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, and the slice instance identification information corresponding to each S-NSSAI in the NSSAI of the HPLMN.

[047] With reference to the second aspect, in a ninth possible implementation of the second aspect, the method additionally includes: sending, via the NSSF, a correspondence between the NSSAI and an NSSAI service area to the AMF.

[048] The correspondence between the NSSAI and a service area is sent to the AMF node, to avoid the correspondence between the NSSAI and a service area being obtained every time the AMF node receives a registration request message from the terminal device, thereby reducing system overhead.

[049] According to a third aspect, a slice-based communications apparatus is provided. The apparatus includes: a transceiver unit and a processing unit, where the processing unit is configured to control the transceiver unit to send a first request message to Petition 870240046306, dated 05 / 31 / 2024, p. 28 / 101 11 / 77 an NSSF node; and the processing unit is further configured to: control the transceiver unit to receive a reply message from the NSSF node, and obtain, based on the reply message, the permitted NSSAIs from a terminal device and service area information corresponding to the permitted NSSAIs.

[050] With reference to the third aspect, in a first possible implementation of the third aspect, when obtaining, based on the response message, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI, the processing unit is specifically configured to: When the reply message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI, it obtains the permitted NSSAI and the service area information corresponding to the permitted NSSAI from the reply message; or when the reply message carries the permitted NSSAI, it obtains the permitted NSSAI from the reply message, and obtains, based on a match between the NSSAI and a service area, the service area information corresponding to the permitted NSSAI; or when the reply message carries the first NSSAI and the service area information corresponding to the first NSSAI, it determines, based on the first NSSAI and the service area information corresponding to the first NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[051] With reference to the third aspect or the first possible implementation of the third aspect, in a second possible implementation of the third aspect, when the response message carries the permitted NSSAI, upon obtaining, based on the correspondence between the NSSAI and a service area of ​​the NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI, the processing unit is additionally configured to: To obtain the match between the NSSAI and a service area from the NSSF node.

[052] With reference to the third aspect or to the first Petition 870240046306, dated 05 / 31 / 2024, p. 29 / 101 12 / 77 possible implementation regarding the second possible implementation of the third aspect, in a third possible implementation of the third aspect, the processing unit is additionally configured to: Consult the terminal device's signature information, where the signature information includes the terminal device's signed NSSAI, the first ported request message, the first NSSAI, and the first NSSAI associated with the signed NSSAI.

[053] With reference to the third aspect or any of the first possible implementations to the third possible implementation of the third aspect, in a fourth possible implementation of the third aspect, the processing unit is further configured to: to control the transceiver unit to receive a registration request message from the terminal device, where the registration request message carries the configured NSSAI, the first request message carries the first NSSAI and the first NSSAI are associated with the configured NSSAI, or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[054] With reference to the third aspect or any of the first possible implementation to the fourth possible implementation of the third aspect, in a fifth possible implementation of the third aspect, the first request message carries the terminal device identification information.

[055] With reference to the third aspect or any of the first possible implementation to the fifth possible implementation of the third aspect, in a sixth possible implementation of the third aspect, the response message additionally includes slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI.

[056] With reference to the third aspect or any of the first possible implementation to the sixth possible implementation of the third aspect, in a seventh possible implementation of the third aspect, the processing unit is further configured to: obtain information from the terminal device's registration area; and determine, based on the terminal device's permitted NSSAIs and the service area information corresponding to those permitted NSSAIs Petition 870240046306, dated 05 / 31 / 2024, p. 30 / 101 13 / 77 that are obtained and the terminal device registration area information, attribute information of a slice instance corresponding to each SNSSAI in the allowed SNSSAI, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the SNSSAI includes a terminal device registration area.

[057] With reference to the third aspect or the seventh possible implementation of the third aspect, in an eighth possible implementation of the third aspect, when the first S-NSSAI is the S-NSSAI that is among the permitted NSSAI and that corresponds to a service area that includes the terminal device registration area, the processing unit is additionally configured to: control the transceiver unit to send a second request message to an NRF device, where the second request message includes the first S-NSSAI or slice instance identification information corresponding to the first S-NSSAI; To control the transceiver unit to receive address information from a target AMF node from the NRF device; and to control the transceiver unit to send the permitted NSSAIs and the service area information corresponding to the permitted NSSAIs to the target AMF node based on the target AMF node's address information.

[058] With reference to the third aspect or the eighth possible implementation of the third aspect, in a ninth possible implementation of the third aspect, the processing unit is additionally configured to: Control the transceiver unit to send slice instance identification information corresponding to each S-NSSAI in the allowed NSSAIs to the target AMF node.

[059] With reference to the third aspect or the eighth possible implementation of the third aspect, in a tenth possible implementation of the third aspect, the processing unit is further configured to: control the transceiver unit to send attribute information to the target AMF node.

[060] With reference to the third aspect or any of the first possible implementations to the tenth possible implementation of the third Petition 870240046306, dated 05 / 31 / 2024, p. 31 / 101 14 / 77 aspect, in an eleventh possible implementation of the third aspect, the allowed NSSAI are the NSSAI of a VPLMN, and the response message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, or the response message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, and slice instance identification information corresponding to each NSSAI in the NSSAI of the HPLMN.

[061] According to a fourth aspect, a slice-based communications device is provided. The device includes: a transceiver unit and a processing unit, wherein the processing unit is configured to control the transceiver unit to receive a first request message from an AMF node; and the processing unit is further configured to control the transceiver unit to send a reply message to the AMF node, wherein the reply message carries the NSSAI, or the NSSAI and service area information corresponding to the NSSAI.

[062] With reference to the fourth aspect, in a first possible implementation of the fourth aspect, NSSAI are the permitted NSSAI.

[063] With reference to the fourth aspect or the first possible implementation of the fourth aspect, in a second possible implementation of the fourth aspect, the first request message carries the first NSSAI and the allowed NSSAI are associated with the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[064] With reference to the fourth aspect or the first possible implementation of the fourth aspect, in a third possible implementation of the fourth aspect, the first request message carries the identification information of a terminal device; and the processing unit is further configured to: query the terminal device's signature information with Petition 870240046306, dated 05 / 31 / 2024, p. 32 / 101 15 / 77 based on identification information, where signature information includes the terminal device's signed NSSAIs and permitted NSSAIs are associated with the signed NSSAIs.

[065] With reference to the fourth aspect, in a fourth possible implementation of the fourth aspect, the first request message carries the first NSSAI, and the NSSAI are the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[066] With reference to the fourth aspect or the fourth possible implementation of the fourth aspect, in a fifth possible implementation of the fourth aspect, the first request message carries the identification information of a terminal device; and the processing unit is further configured to: query the terminal device's signature information based on the identification information, where the signature information includes the terminal device's signed NSSAIs and the first NSSAIs are associated with the signed NSSAIs.

[067] With reference to the fourth aspect or any of the second possible implementation to the fifth possible implementation of the third aspect and the first possible implementation to the fifth possible implementation of the fourth aspect, in a sixth possible implementation of the fourth aspect, the terminal device signature information additionally includes a terminal device type, and the first request message additionally includes the terminal device type.

[068] With reference to the fourth aspect or any of the first possible implementation to the sixth possible implementation of the fourth aspect, in a seventh possible implementation of the fourth aspect, the reply message additionally carries the slice instance identification information corresponding to each S-NSSAI in the NSSAI.

[069] With reference to the fourth aspect or any of the first possible implementation to the seventh possible implementation of the fourth aspect, in an eighth possible implementation of the fourth aspect, the NSSAI are the NSSAI of a VPLMN, and the response message additionally includes the Petition 870240046306, dated 05 / 31 / 2024, p. 33 / 101 16 / 77 The response message either includes the NSSAI of an HPLMN that corresponds to the NSSAI of the VPLMN, or the response message additionally includes the NSSAI of an HPLMN that corresponds to the NSSAI of the VPLMN, and slice instance identification information corresponding to each S-NSSAI in the NSSAI of the HPLMN.

[070] With reference to the fourth aspect, in a ninth possible implementation of the fourth aspect, the processing unit is additionally configured to: to control the transceiver unit to send correspondence between the NSSAI and an NSSAI service area to the AMF.

[071] According to a fifth aspect, a slice-based communications device is provided. The device includes: a transceiver and a processor, where the processor is configured to control the transceiver to send a first request message to an NSSF node; and the processor is further configured to: control the transceiver to receive a reply message from the NSSF node, and obtain, based on the reply message, the permitted NSSAI of a terminal device and service area information corresponding to the permitted NSSAI.

[072] With reference to the fifth aspect, in a first possible implementation of the fifth aspect, when obtaining, based on the response message, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI, the processor is specifically configured to: When the reply message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI, it obtains the permitted NSSAI and the service area information corresponding to the permitted NSSAI from the reply message; or when the reply message carries the permitted NSSAI, it obtains the permitted NSSAI from the reply message, and obtains, based on a match between the NSSAI and a service area, the service area information corresponding to the permitted NSSAI; or when the reply message carries the first NSSAI and the service area information corresponding to the first NSSAI, Petition 870240046306, dated 05 / 31 / 2024, p. 34 / 101 17 / 77 determine, based on the first NSSAI and the service area information corresponding to the first NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[073] With reference to the fifth aspect or the first possible implementation of the fifth aspect, in a second possible implementation of the fifth aspect, when the response message carries the permitted NSSAI, upon obtaining, based on the correspondence between the NSSAI and a service area of ​​the NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI, the processor is additionally configured to: To obtain the match between the NSSAI and a service area from the NSSF node.

[074] With reference to the fifth aspect, or to both the first possible implementation and the second possible implementation of the fifth aspect, in a third possible implementation of the fifth aspect, the processor is further configured to: Consult the terminal device's signature information, where the signature information includes the terminal device's signed NSSAIs, the first ported request message, the first NSSAIs, and the first NSSAIs associated with the signed NSSAIs.

[075] With reference to the fifth aspect or any of the first possible implementation to the third possible implementation of the fifth aspect, in a fourth possible implementation of the fifth aspect, the processor is further configured to: To control the transceiver to receive a registration request message from the terminal device, where the registration request message carries the configured NSSAI, the first request message carries the first NSSAI and the first NSSAI are associated with the configured NSSAI, or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[076] With reference to the fifth aspect or any of the first possible implementation to the fourth possible implementation of the fifth aspect, in a fifth possible implementation of the fifth aspect, the first request message carries the identification information of Petition 870240046306, dated 05 / 31 / 2024, p. 35 / 101 18 / 77 terminal device.

[077] With reference to the fifth aspect or any of the first possible implementation to the fifth possible implementation of the fifth aspect, in a sixth possible implementation of the fifth aspect, the response message additionally includes slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI.

[078] With reference to the fifth aspect or any of the first possible implementation to the sixth possible implementation of the fifth aspect, in a seventh possible implementation of the fifth aspect, the processor is additionally configured to: to obtain information from the terminal device's registration area; and to determine, based on the terminal device's allowed NSSAI and the service area information corresponding to the allowed NSSAI that is obtained and the terminal device's registration area information, the attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAI, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the NSSAI includes a terminal device registration area.

[079] With reference to the fifth aspect or the seventh possible implementation of the fifth aspect, in an eighth possible implementation of the fifth aspect, when the first S-NSSAI is the S-NSSAI that is among the permitted NSSAI and that corresponds to a service area that includes the terminal device registration area, the processor is additionally configured to: control the transceiver to send a second request message to an NRF device, where the second request message includes the first S-NSSAI or slice instance identification information corresponding to the first S-NSSAI; To control the transceiver to receive address information from a target AMF node from the NRF device; and to control the transceiver to send the permitted NSSAIs and the service area information corresponding to the permitted NSSAIs to the target AMF node based on the target AMF node's address information.

[080] With reference to the fifth aspect or the eighth possible implementation of the fifth aspect, in a ninth possible implementation of the fifth Petition 870240046306, dated 05 / 31 / 2024, p. 36 / 101 19 / 77 aspect ratio, the processor is additionally configured for: Control the transceiver to send slice instance identification information corresponding to each S-NSSAI in the allowed NSSAIs to the target AMF node.

[081] With reference to the fifth aspect or the eighth possible implementation of the fifth aspect, in a tenth possible implementation of the fifth aspect, the processor is additionally configured to: Control the transceiver to send the attribute information to the target AMF node.

[082] With reference to the fifth aspect or any of the first possible implementation to the tenth possible implementation of the fifth aspect, in an eleventh possible implementation of the fifth aspect, the allowed NSSAI are the NSSAI of a VPLMN, and the response message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, or the response message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, and slice instance identification information corresponding to each S-NSSAI in the NSSAI of the HPLMN.

[083] According to a sixth aspect, a slice-based communications device is provided. The device includes: a transceiver and a processor, wherein the processor is configured to control the transceiver to receive a first request message from an AMF node; and the processor is further configured to control the transceiver to send a reply message to the AMF node, wherein the reply message carries the NSSAI, or the NSSAI and the service area information corresponding to the NSSAI.

[084] With reference to the sixth aspect, in a first possible implementation of the sixth aspect, NSSAI are the permitted NSSAI.

[085] With reference to the sixth aspect or the first possible implementation of the sixth aspect, in a second possible implementation of the sixth aspect, the first request message carries the first NSSAI and the permitted NSSAI are associated with the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the Petition 870240046306, dated 05 / 31 / 2024, p. 37 / 101 The first 20 / 77 NSSAI are associated with configured NSSAI, or the first NSSAI are associated with both signed and configured NSSAI.

[086] With reference to the sixth aspect or the first possible implementation of the sixth aspect, in a third possible implementation of the sixth aspect, the first request message carries the identification information of a terminal device; and the processor is further configured to: Consult the terminal device's signature information based on the identification information, where the signature information includes the terminal device's signed NSSAIs, and the permitted NSSAIs are associated with the signed NSSAIs.

[087] With reference to the sixth aspect, in a fourth possible implementation of the sixth aspect, the first request message carries the first NSSAI, and the NSSAI are the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[088] With reference to the sixth aspect or the fourth possible implementation of the sixth aspect, in a fifth possible implementation of the sixth aspect, the first request message carries the identification information of a terminal device; and the processor is additionally configured to: Consult the terminal device's signature information based on the identification information, where the signature information includes the terminal device's signed NSSAIs, and the first NSSAIs are associated with the signed NSSAIs.

[089] With reference to the sixth aspect or any of the second possible implementation to the fifth possible implementation of the fifth aspect and the first possible implementation to the fifth possible implementation of the sixth aspect, in a sixth possible implementation of the sixth aspect, the terminal device signature information additionally includes a terminal device type, and the first request message additionally includes the terminal device type.

[090] With reference to the sixth aspect or any of the first Petition 870240046306, dated 05 / 31 / 2024, p. 38 / 101 21 / 77 possible implementation of the sixth aspect, in a seventh possible implementation of the sixth aspect, the response message additionally carries the slice instance identification information corresponding to each S-NSSAI in the NSSAI.

[091] With reference to the sixth aspect or any of the first possible implementation to the seventh possible implementation of the sixth aspect, in an eighth possible implementation of the sixth aspect, the NSSAI are the NSSAI of a VPLMN, and the reply message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, or the reply message additionally includes the NSSAI of an HPLMN that correspond to the NSSAI of the VPLMN, and slice instance identification information corresponding to each S-NSSAI in the HPLMN NSSAI.

[092] With reference to the sixth aspect, in a ninth possible implementation of the sixth aspect, the processor is additionally configured to: to control the transceiver in order to send correspondence between the NSSAI and an NSSAI service area to the AMF.

[093] According to a seventh aspect, a computer storage medium is provided. The computer storage medium is configured to store a computer software instruction executed by the processor provided in the fifth aspect, to perform the method provided in the first aspect and the possible implementations of the first aspect.

[094] According to an eighth aspect, a computer storage medium is provided. The computer storage medium is configured to store a computer software instruction executed by the processor provided in the sixth aspect, to perform the method provided in the second aspect and the possible implementations of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[095] Figure 1 is a schematic diagram of a system architecture, according to an embodiment of the present invention;

[096] Figure 2 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present Petition 870240046306, dated 05 / 31 / 2024, page 39 / 101 22 / 77 invention;

[097] Figure 3 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[098] Figure 4 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[099] Figure 5 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0100] Figure 6 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0101] Figure 7 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0102] Figure 8 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0103] Figure 9 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0104] Figure 10 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0105] Figure 11 is a schematic flowchart of a slice-based communications method, according to an embodiment of the present invention;

[0106] Figure 12 is a schematic structural diagram of a slice-based communications apparatus according to an embodiment of the present invention;

[0107] Figure 13 is a schematic structural diagram of a slice-based communication device according to an embodiment of the present invention; Petition 870240046306, dated 05 / 31 / 2024, p. 40 / 101 23 / 77

[0108] Figure 14 is a schematic structural diagram of a slice-based communications device according to an embodiment of the present invention; and

[0109] Figure 15 is a schematic structural diagram of a slice-based communications device according to an embodiment of the present invention. DESCRIPTION OF THE MODALITIES

[0110] The following text clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the attached drawings in the embodiments of the present invention.

[0111] Figure 1 shows an example of a system architecture applied to an embodiment of the present invention. Slice-based communication control can be implemented based on the system architecture.

[0112] A network slice divides a physical network into a plurality of virtual networks, so that a plurality of services are implemented relatively independently while sharing the same network infrastructure. Each “network slice” performs the customization and adaptation of a network function and orchestration and management of a corresponding network function based on a service scenario requirement. Network functions include coverage area, duration, capacity, speed, latency, reliability, security, availability, and the like.

[0113] A network slice can be considered as an instantiated network core architecture. Currently, the Third-Generation Partnership Project (3GPP) divides network slice instances into an enhanced mobile broadband (eMBB) service, a massive machine-type communication (mTC) service, and an ultra-reliable and low-latency communications (URLLC) service. eMBB is primarily aimed at endpoints with relatively high rate and mobility requirements, for example, mobile phones and multimedia devices. mMTC is mainly used for Internet of Things devices, or other large-scale services having relatively low rate and mobility requirements. Petition 870240046306, dated 05 / 31 / 2024, page 41 / 101 24 / 77 mobility. URLLC is primarily aimed at the Internet of Vehicles, or other types of services and devices having extremely high latency and reliability requirements. For example, a mobile phone user might access an eMBB network slice to download or watch a high-definition 4K video at high speed. A sensor device might access an mMTC network slice to transmit a small data packet and update a system setting. A user might simultaneously access one, more, or all network slices to meet a service requirement and obtain a relatively desirable user experience.

[0114] The system architecture of the slice-based communications method provided in this embodiment of the present invention includes a Radio Access Network (RAN) node 101, an Access and Management Function (AMF) node 102, a Network Slice Selection Function (NSSF) node 103, and a plurality of slices 104. Specific functions of each slice 104 include at least one session management function (SMF) and one user plane function (UPF). In other words, each slice 103 includes one SMF node and one UPF node. A terminal device accesses the plurality of slices through the use of the RAN node 101, and the AMF node 102 can provide information about a slice instance supporting the terminal device to the terminal device.

[0115] A RAN node can be an access point (AP) in a wireless local area network (WLAN), or a base transceiver station (BTS) in a Global System for Mobile Communications (GSM) or Code-division multiple access (CDMA), or it can be a Node B (NB) in Wideband Code Division Multiple Access (WCDMA), or it can be an Evolutionary Node B (eNB or eNodeB) in Long Term Evolution (LTE), a regenerative station, an access point, an in-vehicle device, a wearable device, a network device in a future 5G network, or a network device in a Petition 870240046306, dated 05 / 31 / 2024, page 42 / 101 25 / 77 future evolved public land mobile network (PLMN), for example, a base station that can connect to a 5G network core device, a Transmission and Reception Point (TRP), a Centralized Unit (CU), a Distributed Unit (DU), or similar.

[0116] The AMF 102 node has a network function for managing access and mobility of the terminal device, communicates with a RAN, and provides a specific slice to the terminal device.

[0117] The NSSF 103 node communicates with the AMF 102 node, and is configured to: select a slice that supports the terminal device for the terminal device, and transmit information about the slice that supports the terminal device to the AMF 102 node.

[0118] In this embodiment of the present invention, the terminal device may be a device having a wireless fidelity module (WiFi), for example, a mobile phone, a wrist ring, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a personal digital assistant (PDA) device, an in-vehicle device, a wearable device, a sensor having a network access function, or the like, and is not limited to a communication terminal.

[0119] Based on the previous description, Figure 2 shows an example of a slice-based communication method procedure according to an embodiment of the present invention. Slice-based communication can be implemented in the procedure. The method for slice-based communication is described below with reference to Figure 1 and Figure 2.

[0120] As shown in Figure 2, the procedure specifically includes:

[0121] Step 201: An AMF node sends an initial request message to an NSSF node.

[0122] In this embodiment of the present invention, after accessing a RAN node in a registration process, a terminal device needs to access a network core slice supported by the terminal device. Petition 870240046306, dated 05 / 31 / 2024, page 43 / 101 26 / 77 In this case, if the AMF node selected by the RAN node cannot provide a network core slice service required by the UE, the AMF node will send the first request message to the NSSF node. The first request message is used to request or query the slice information associated with the terminal device. The first request message may contain either the first NSSAI or terminal device identification information. Optionally, the first request message may alternatively contain both the first NSSAI and terminal device identification information. The first NSSAI carried by the first request message is used to request that the NSSF node return the service area information corresponding to the first NSSAI or the allowed NSSAI of the terminal device and the service area information corresponding to the allowed NSSAI.Terminal device identification information is used by the NSSF node to query terminal device subscription information. Terminal device identification information can be carried by a registration request message that is sent by the terminal device, forwarded by the RAN node, and received by the AMF node, or it can be obtained by the AMF from a terminal device context. Terminal device identification information can be a permanent identifier of the SUPI terminal device. Optionally, the registration request message can be an initial registration request message or a tracking area location update request message.

[0123] It should be noted that in this embodiment of the present invention, NSSAI is a set of a plurality of S-NSSAI parts, and a slice instance may support one S-NSSAI part, or may support a plurality of S-NSSAI parts, or an S-NSSAI part may correspond to one or more slice instances. When an SNSSAI part corresponds to a plurality of slice instances, in this embodiment of the present invention, a slice instance can be determined by using a Network Slice instance identifier (NSI ID).

[0124] In one implementation, the AMF node queries the terminal device's signature information, and adds the information Petition 870240046306, dated 05 / 31 / 2024, p. 44 / 101 27 / 77 of the terminal device signature or a portion of the signature information in the first request message. For example, the AMF node might send a signature information query request to a home UDM device from the terminal device. The signature information query request carries a terminal device identifier and is used to query the terminal device's signature information. The UDM device returns the terminal device signature information to the AMF node, and the terminal device signature information includes the terminal device's signed NSSAI. In this case, the AMF node determines the first NSSAI based on the signed NSSAI. Therefore, the first NSSAI carried by the first request message is associated with the signed NSSAI. In other words, the first NSSAI is related to the terminal device's signed NSSAI.For example, the first NSSAI could be a universal set or a subset of the subscribed NSSAI.

[0125] Optionally, the registration request message received by the AMF node from the terminal device additionally carries the configured NSSAI. The AMF node determines the first NSSAI based on the configured NSSAI. In this case, the first NSSAI carried by the first request message are associated with the configured NSSAI. In other words, the first NSSAI are related to the configured NSSAI. For example, the first NSSAI may be a universal set or a subset of the configured NSSAI.

[0126] Optionally, the registration request message received from the terminal device also carries the configured NSSAIs while the AMF node obtains the signed NSSAIs from the terminal device by query. The AMF node determines the first NSSAIs based on the signed NSSAIs and the configured NSSAIs. In this case, the first NSSAIs carried by the first request message are associated with both the signed NSSAIs and the configured NSSAIs. For example, the first NSSAIs may be a universal set or a subset of the signed NSSAIs, it may be a universal set or a subset of the configured NSSAIs, or it may be an intersection set of the signed NSSAIs and the configured NSSAIs. Petition 870240046306, dated 05 / 31 / 2024, p. 45 / 101 28 / 77

[0127] Optionally, the terminal device signature information that is obtained by the AMF node via query may additionally include a terminal device type. In this case, the first request message may also additionally include the terminal device type. The terminal device type is used by the NSSF node to additionally determine the slice instance identification information corresponding to each S-NSSAI in the allowed terminal device NSSAI.

[0128] In another implementation, when the first request message sent by the AMF node to the NSSF node carries the terminal device identification information, the NSSF node can autonomously query the terminal device signature information from the terminal device's home UDM device based on the terminal device identification information.

[0129] Step 202: The NSSF node receives the first request message from the AMF node, and sends a response message to the AMF node.

[0130] After receiving the first request message, the NSSF node sends the reply message to the AMF node. The reply message may carry NSSAI, or the reply message may carry NSSAI and service area information corresponding to NSSAI.

[0131] For example, step 202 can be performed in any of the following ways:

[0132] (1) When the first request message carries the first NSSAI, the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI carried by the terminal device registration request message or the first NSSAI are associated with both the signed and configured NSSAI. The NSSF node can determine the terminal device's allowed NSSAI based on the first NSSAI, where the allowed NSSAI are associated with the first NSSAI. For example, the allowed NSSAI can be a universal set or a subset of the first NSSAI. In this case, the reply message sent by the NSSF node to the AMF node carries the NSSAI, where the NSSAI are the allowed NSSAI. Optionally, the reply message Petition 870240046306, dated 05 / 31 / 2024, p. 46 / 101 29 / 77 may additionally carry service area information corresponding to permitted NSSAIs.

[0133] (2) When the first request message carries the terminal device identification information, the NSSF node additionally queries the terminal device signature information from the terminal device's home UDM device based on the terminal device identification information. The signature information may include the terminal device's signed NSSAIs. The NSSF node obtains the allowed NSSAIs based on the signed NSSAIs. For example, the allowed NSSAIs may be a universal set or a subset of the signed NSSAIs. In this case, the reply message sent by the NSSF node to the AMF node carries the NSSAI, where the NSSAI are the allowed NSSAIs. Optionally, the reply message may additionally carry the service area information corresponding to the allowed NSSAIs.

[0134] (3) When the first request message carries the terminal device identification information and the first NSSAI, the NSSF node can query the terminal device signature information from the terminal device's home UDM device based on the terminal device identification information. The signature information may include the terminal device's signed NSSAIs. The NSSF node obtains the allowed NSSAIs based on the signed NSSAIs and the first NSSAIs. The allowed NSSAIs are associated with the first NSSAIs and the signed NSSAIs. For example, the allowed NSSAIs may be a universal set or a subset of the signed NSSAIs, they may be a universal set or a subset of the first NSSAIs, or they may be an intersection set of the signed NSSAIs and the first NSSAIs. The first NSSAIs may be the configured NSSAIs carried by the terminal device registration request message.In this case, the reply message sent by the NSSF node to the AMF node carries the NSSAI, where the NSSAI are the permitted NSSAI. Optionally, the reply message may additionally carry the service area information corresponding to the permitted NSSAIs.

[0135] (4) When the first ported request message as Petition 870240046306, dated 05 / 31 / 2024, p. 47 / 101 30 / 77 first NSSAI, the NSSAI carried by the reply message may be the first NSSAI, and the reply message may carry a service area corresponding to the first NSSAI.

[0136] (5) When the first request message carries the terminal device identification information, the NSSF node can additionally query the terminal device signature information from the terminal device's home UDM device based on the terminal device identification information. The signature information may include the terminal device's signed NSSAIs. The NSSF node obtains the first NSSAIs based on the signed NSSAIs. The first NSSAIs are associated with the signed NSSAIs. For example, the first NSSAIs may be a universal set or a subset of the signed NSSAIs. The reply message sent by the NSSF node to the AMF node carries the first NSSAIs and the service area information corresponding to the first NSSAIs.

[0137] For example, the permitted NSSAI (or the first NSSAI) carried by the reply message includes S-NSSAI 1, S-NSSAI 2 and S-NSSAI 3, and the reply message carries the content shown in Table 1. Table 1 1 S-NSSAI 1 Service Area 1 2 S-NSSAI 2 Service Area 2 3 S-NSSAI 3 Service Area 3

[0138] Optionally, in the various previous implementations, the response message may additionally carry slice instance identification information corresponding to each S-NSSAI in the NSSAI. For example, when the NSSAIs carried by the response message are the allowed NSSAIs, the response message may additionally carry slice instance identification information corresponding to each SNSSAI in the allowed NSSAIs. When the NSSAIs carried by the response message are the first NSSAIs, the response message may additionally carry slice instance identification information corresponding to each S-NSSAI in the first NSSAIs. For example, the response message additionally carries the identification information Petition 870240046306, dated 05 / 31 / 2024, p. 48 / 101 31 / 77 of the slice instances correspond to S-NSSAI, as shown in Table 2. Table 2 1 S-NSSAI 1 NSI ID 1 Service area 1 2 S-NSSAI 2 NSI ID 2 Service area 2 3 S-NSSAI 3 NSI ID 3 Service area 3

[0139] Optionally, when the NSSAIs carried by the reply message are the NSSAIs of a VPLMN, this indicates that the terminal device is currently in a roaming state. In this case, the reply message may additionally include the NSSAIs of an HPLMN that correspond to the NSSAIs of the VPLMN. Alternatively, the reply message may additionally include the NSSAIs of the HPLMN that correspond to the NSSAIs of the VPLMN, and the slice instance identification information corresponding to each S-NSSAI in the NSSAIs of the HPLMN. For example, in this case, the NSSF node is an NSSF node of the VPLMN. The VPLMN NSSF node can obtain, based on a match between the VPLMN NSSAI and the HPLMN NSSAI, the HPLMN NSSAI that correspond to the VPLMN NSSAI, to select a suitable HPLMN slice instance when configuring a home-routed session that is sustained in a roaming scenario.

[0140] Optionally, the first request message may additionally carry terminal device registration area information, and the terminal device registration area information is obtained by the AMF node based on the RAN node location information. In this case, the NSSF node may determine, based on the terminal device's allowed NSSAI and the service area information corresponding to the allowed NSSAI that is obtained and the terminal device registration area information, attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAI, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a terminal device registration area. The response message carries the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAI.

[0141] Step 203: The AMF node receives the response message to Petition 870240046306, dated 05 / 31 / 2024, p. 49 / 101 32 / 77 of the NSSF node, and obtains, based on the response message, the permitted NSSAI of a terminal device and service area information corresponding to the permitted NSSAI.

[0142] After receiving the reply message from the NSSF node, the AMF node can obtain, in different ways based on different contents carried by the reply message, the allowed NSSAI of the terminal device and the service area information corresponding to the allowed NSSAI.

[0143] For example, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI can be obtained in any of the following ways:

[0144] (1) When the reply message carries the permitted NSSAI and the corresponding service area information, the AMF node can directly obtain the permitted NSSAI and the corresponding service area information.

[0145] (2) When the reply message carries the permitted NSSAI, the AMF node obtains the permitted NSSAI, and obtains, based on a match between the NSSAI and a service area, the service area information corresponding to the permitted NSSAI. In this way, the AMF node can first obtain a match between the NSSAI and a service area from the NSSF node, and based on the match between the NSSAI and a service area and the permitted NSSAI, obtains the service area information corresponding to the permitted NSSAI. Optionally, after obtaining the match between the NSSAI and a service area, the AMF node can store the match locally, so that the match can be conveniently invoked at any time during use, and no longer needs to be obtained from the NSSF node.

[0146] (3) When the reply message carries the first NSSAI and the service area information corresponding to the first NSSAI, based on the first NSSAI and the service area information corresponding to the first NSSAI, the AMF node determines the allowed NSSAI and the service area information corresponding to the allowed NSSAI.

[0147] Optionally, in the various ways above, the message Petition 870240046306, dated 05 / 31 / 2024, p. 50 / 101 Response 33 / 77 received by the AMF node may additionally carry the slice instance identification information corresponding to each SNSSAI in the permitted SNSSAIs.

[0148] Optionally, the AMF node may additionally determine, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device. For example, in Table 1, a service area of ​​a slice instance corresponding to S-NSSAI 1 includes the registration area of ​​the terminal device, and a service area of ​​a slice instance corresponding to S-NSSAI 3 does not include the registration area of ​​the terminal device.

[0149] Optionally, after obtaining the allowed NSSAI and the service area information corresponding to the allowed NSSAI, upon discovering that the AMF node is not an AMF node supported by the terminal device, the AMF node may reallocate the terminal device to a target AMF node, and may additionally send a second request message to an NRF device. The second request message includes the first S-NSSAI or an identifier of a slice instance corresponding to the first S-NSSAI. The first S-NSSAI is the S-NSSAI that is from the allowed NSSAI and that corresponds to a service area that includes the terminal device's registration area. A service area of ​​the slice instance corresponding to the first S-NSSAI includes the terminal device's registration area. The second request message is used to request the NRF device to return address information of the target AMF node from the terminal device.After receiving the target AMF node address information from the NRF device, the AMF node sends the permitted NSSAIs and the corresponding service area information to the target AMF node based on the target AMF node's address information. The target AMF node stores the permitted NSSAIs and the corresponding service area information. Petition 870240046306, dated 05 / 31 / 2024, p. 51 / 101 34 / 77 allowed, to determine a slice instance in response to a session configuration request upon receiving the session configuration request from the endpoint device.

[0150] Optionally, the AMF node can additionally send the slice instance identification information corresponding to each single network slice selection assistance information (S-NSSAI) in the NSSAIs allowed for the target AMF node. Optionally, the AMF node can additionally send the slice instance attribute information corresponding to each S-NSSAI in the NSSAIs allowed for the target AMF node. This can avoid repeated interaction between the target AMF and the NSSF node, and improve signaling exchange and processing efficiency. Optionally, the target AMF node can indicate to the terminal device whether each S-NSSAI in the NSSAIs allowed is sustained or left in the corresponding registration area for the terminal device, as shown in Table 5.This can avoid the overhead of additional signaling caused by the fact that a requested S-NSSAI service area does not include the registration area; that is, the S-NSSAI is not sustained in the registration area when the terminal device subsequently initiates a session request.

[0151] In the previous embodiment, the AMF node sends the first request message to the NSSF node; and the AMF node receives the reply message from the NSSF node, and obtains, based on the reply message, the allowed NSSAI network slice selection assistance information from the terminal device and the service area information corresponding to the allowed NSSAI. The AMF node obtains the allowed NSSAI network slice selection assistance information from the terminal device and the service area information corresponding to the allowed NSSAI from the NSSF node, to avoid repeated interaction between the AMF node and the NSSF node after a change in the registration area caused by the terminal device moving. Therefore, this improves signaling exchange and processing efficiency and reduces system overhead.

[0152] Based on the previous description, to better describe the embodiments of the present invention, a slice-based communication procedure provided in the embodiments of the present invention is described below in specific implementation scenarios. Petition 870240046306, dated 05 / 31 / 2024, page 52 / 101 35 / 77

[0153] As shown in Figure 3, when a terminal device is in a non-roaming scenario, a slice-based communication procedure includes the following specific steps.

[0154] Step 301: An AMF node sends a subscription information query request message to a UDM device.

[0155] After receiving a registration request message that is sent via a terminal device and forwarded by a RAN, the AMF node can query the terminal device's signature information from a UDM device. The signature information query request message carries a SUPI from the terminal device. The terminal device's signature information is queried using the terminal device's SUPI. Optionally, the registration request message can additionally include the configured NSSAI.

[0156] Step 302. The UDM device returns a signature information response message to the AMF node.

[0157] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the AMF node, and returns the signature information response message to the AMF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's signed NSSAI, and may optionally include additional terminal device type information.

[0158] Step 303: The AMF node sends an initial request message to an NSSF node.

[0159] The first request message carries the first NSSAI. The first NSSAI can be obtained by the AMF node based on the configured NSSAI carried by the terminal device's signature information and / or a terminal device registration request message. The first NSSAIs are associated with the signature information and / or the configured NSSAIs.

[0160] Step 304: The NSSF node obtains the permitted NSSAIs and the service area information corresponding to the permitted NSSAIs. Petition 870240046306, dated 05 / 31 / 2024, p. 53 / 101 36 / 77

[0161] The NSSF node can obtain, based on a match between the NSSAI and a service area that is obtained from an OAM system by the NSSF node, the first NSSAI, and other information, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI. The permitted NSSAI are associated with the first NSSAI and can be a universal set or a subset of the first NSSAI.

[0162] Step 305: The NSSF node sends a response message to the AMF node.

[0163] The reply message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI. Optionally, the reply message may additionally include slice instance identification information corresponding to each NSSAI in the permitted NSSAIs, for example, as shown in Table 1 or Table 2.

[0164] Step 306: The AMF node sends a network element discovery request to an NRF device.

[0165] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and information from the terminal device's registration area, the AMF node determines attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a terminal device registration area.

[0166] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to the S-NSSAI indicates whether a service area of ​​the slice instance corresponding to the S-NSSAI or the slice instance includes the terminal device registration area.

[0167] The content included in the network element discovery request can be further determined based on the content of the response message sent by the NSSF node. When the response message carries the content shown in Table 1, the content that can be carried by the network element discovery request is shown in Petition 870240046306, dated 05 / 31 / 2024, page 54 / 101 37 / 77 Table 3. Assuming that a service area of ​​a slice instance having a slice instance identifier of 3 does not include the terminal device registration area, the network element discovery request will only carry information from slice instances having slice instance identifiers 1 and 2. When the response message carries the content shown in Table 2, the content that can be carried by the network element discovery request is shown in Table 4. Assuming that a service area of ​​a slice instance corresponding to slice S-NSSAI 3 does not include the terminal device registration area, the network element discovery request will only carry information from slices S-NSSAI 1 and 2. Table 3 1 NSI ID 1 Service area 1 2 NSI ID 2 Service area 2 Table 4 1 S-NSSAI 1 Service Area 1 2 S-NSSAI 2 Service Area 2

[0168] Step 307: The NRF device sends a Network Element Discovery Request Response message to the AMF node.

[0169] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0170] Step 308. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 305 to a target AMF node.

[0171] The no-access stratum message is the registration request message in step 301.

[0172] Optionally, the allowed NSSAIs include the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs in step 306. Alternatively, the AMF node sends the information Petition 870240046306, dated 05 / 31 / 2024, p. 55 / 101 38 / 77 attribute for the target AMF node.

[0173] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 305 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 305, and the registration request message to the target AMF node.

[0174] Optionally, information that can be sent by the AMF node to the target AMF node through the use of the RAN node may additionally include attribute information in step 306.

[0175] Step 309: The target AMF node stores the allowed NSSAI and the service area information corresponding to the allowed NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request when receiving the session configuration request from the endpoint device.

[0176] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0177] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node. Table 5 Petition 870240046306, dated 05 / 31 / 2024, p. 56 / 101 39 / 77 1 S-NSSAI 1 Allowed or supported 2 S-NSSAI 2 Allowed or supported 3 S-NSSAI 3 Not allowed or supported

[0178] In this mode, after obtaining the permitted NSSAI and the service area information corresponding to the permitted NSSAI, the NSSF node sends the permitted NSSAI and the service area information corresponding to the permitted NSSAI to the AMF node, so that the AMF node selects an appropriate slice instance for the terminal device.

[0179] As shown in Figure 4, an interface is provided between an NSSF node and a UDM device, and the NSSF node and the UDM device can communicate with each other when a terminal device is in a non-roaming scenario. In this scenario, the NSSF node can autonomously query the terminal device's subscription information. In this scenario, a slice-based communication procedure includes the following specific steps.

[0180] Step 401. An AMF node receives a registration request message that is sent via a terminal device and forwarded by a RAN.

[0181] Step 402: The AMF node sends an initial request message to an NSSF node.

[0182] When the AMF node discovers that the AMF node cannot provide a service to the terminal device, or the AMF cannot determine whether the AMF node can provide a service to the terminal device, the AMF sends the first request message. The first request message carries a SUPI from the terminal device. If the registration request message sent by the terminal device carries the configured NSSAI, the first request message may additionally carry the configured NSSAI. If the registration request message sent by the terminal device does not carry the configured NSSAI, the first request message will not carry the configured NSSAI.

[0183] Step 403: The NSSF node sends a subscription information query request to a UDM device.

[0184] The subscription information query request includes Petition 870240046306, dated 05 / 31 / 2024, page 57 / 101 40 / 77 is the SUPI of the terminal device that is carried by the first request message that is sent by the AMF node and received by the NSSF node. The NSSF node queries terminal device signature information from the UDM based on the terminal device's SUPI.

[0185] Step 404. The UDM device returns a signature information response message to the NSSF node.

[0186] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the NSSF node, and returns the signature information response message to the NSSF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's signed NSSAI, and may optionally include additional terminal device type information.

[0187] Step 405: The NSSF node obtains the permitted NSSAIs from a terminal device and service area information corresponding to the permitted NSSAIs.

[0188] The NSSF node can obtain the permitted NSSAI from the terminal device and the service area information corresponding to the permitted NSSAI based on information such as a match between the NSSAI and a service area obtained from an OAM system by the NSSF node, the signed NSSAI carried by the terminal device signature information obtained from the UDM, and the configured NSSAI carried by the first request message sent by the AMF node. The permitted NSSAI are associated with the signed NSSAI and / or the configured NSSAI and can be a universal set or a subset of the signed NSSAI, a universal set or a subset of the configured NSSAI, or an intersection set of the signed and configured NSSAI.

[0189] Step 406: The NSSF node sends a response message to the AMF node.

[0190] The reply message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI. Optionally, the reply message may additionally include Petition 870240046306, dated 05 / 31 / 2024, p. 58 / 101 41 / 77 instance identification information for each slice corresponding to each SNSSAI in the permitted SNSSAIs, for example, as shown in Table 1 or Table 2.

[0191] Step 407: The AMF node sends a network element discovery request to an NRF device.

[0192] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0193] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0194] The content included in the network element discovery request can be further determined based on the content of the response message sent by the NSSF node. When the response message carries the content shown in Table 1, the content that can be carried by the network element discovery request is shown in Table 3. Assuming that a service area of ​​a slice instance having a slice instance identifier 3 does not include the terminal device registration area, the network element discovery request carries only information from slice instances having slice instance identifiers 1 and 2. When the response message carries the content shown in Table 2, the content that can be carried by the network element discovery request is shown in Table 4.Assuming that a service area of ​​a slice instance corresponding to slice S-NSSAI 3 does not include the terminal device registration area, the network element discovery request will only carry information from slices S-NSSAI 1 and 2.

[0195] Step 408: The NRF device sends a message of Petition 870240046306, dated 05 / 31 / 2024, page 59 / 101 42 / 77 Network element discovery request response to the AMF node.

[0196] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0197] Step 409. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 406 to a target AMF node.

[0198] The no-access stratum message is the log request message in step 401.

[0199] Optionally, the allowed NSSAI include the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAI in step 407. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0200] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 406 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 406, and the registration request message to the target AMF node.

[0201] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include attribute information in step 407.

[0202] Step 410: The target AMF node stores the allowed NSSAI and the service area information corresponding to the allowed NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request upon receiving the configuration request. Petition 870240046306, dated 05 / 31 / 2024, pages 60 / 101 43 / 77 session of the terminal device.

[0203] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0204] For example, the indication can be carried by a registration reply message sent by the AMF to the terminal device through the use of the RAN node. Compared with the mode shown in Figure 3, in the mode shown in Figure 4, the interface is provided between the NSSF node and the UDM device, the NSSF node can directly obtain the signature information from the terminal device, and the first request message sent by the AMF node to the NSSF node can carry the SUPI of the terminal device.

[0205] As shown in Figure 5, when a terminal device is in a non-roaming scenario, a slice-based communication procedure includes the following specific steps.

[0206] Step 501: An AMF node sends a subscription information query request message to a UDM device.

[0207] After receiving a registration request message that is sent via a terminal device and forwarded by a RAN, the AMF node can query the terminal device's signature information from the UDM device. The signature information query request message carries a SUPI from the terminal device. The terminal device's signature information is queried using the terminal device's SUPI. Optionally, the registration request message can additionally include the configured NSSAI. Petition 870240046306, dated 05 / 31 / 2024, pp. 61 / 101 44 / 77

[0208] Step 502. The UDM device returns a signature information response message to the AMF node.

[0209] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the AMF node, and returns the signature information response message to the AMF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's signed NSSAI, and may optionally include additional terminal device type information.

[0210] Step 503: The AMF node sends an initial request message to an NSSF node.

[0211] The first request message carries the first NSSAI. The first NSSAI can be obtained by the AMF node based on the configured NSSAI carried by the terminal device signature information and / or the terminal device registration request message. The first NSSAI are associated with the signature information and / or the configured NSSAI.

[0212] Step 504: The NSSF node sends a response message to the AMF node.

[0213] The reply message carries the service area information corresponding to the first NSSAIs. After receiving the first request message sent by the AMF node, the NSSF node can obtain, based on a match between the NSSAI and a service area obtained from an OAM system and the first NSSAI, the service area information corresponding to the first NSSAI. Optionally, the reply message may additionally include slice instance identification information corresponding to each S-NSSAI in the first NSSAIs, for example, as shown in Table 1 or Table 2.

[0214] Step 505: The AMF node obtains the permitted NSSAIs and the service area information corresponding to the permitted NSSAIs.

[0215] Based on service area information corresponding to the first NSSAI and carried by the reply message sent by an NSSAI node, the first NSSAI, and the NSSAI Petition 870240046306, dated 05 / 31 / 2024, p. 62 / 101 45 / 77 signed, the AMF node obtains the permitted NSSAIs from the terminal device and the service area information corresponding to the permitted NSSAIs. The permitted NSSAIs are associated with the first NSSAI, or the permitted NSSAIs are associated with the signed NSSAIs.

[0216] Step 506: The AMF node sends a network element discovery request to an NRF device.

[0217] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0218] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0219] The content included in the network element discovery request can be further determined based on the content of the response message sent by the NSSF node. When the response message carries the content shown in Table 1, the content that can be carried by the network element discovery request is shown in Table 3. Assuming that a service area of ​​a slice instance having a slice instance identifier 3 does not include the terminal device registration area, the network element discovery request carries only information from slice instances having slice instance identifiers 1 and 2. When the response message carries the content shown in Table 2, the content that can be carried by the network element discovery request is shown in Table 4.Assuming that a service area of ​​a slice instance corresponding to slice S-NSSAI 3 does not include the terminal device registration area, the network element discovery request will only carry information from slices S-NSSAI 1 and 2. Petition 870240046306, dated 05 / 31 / 2024, page 63 / 101 46 / 77

[0220] Step 507: The NRF device sends a Network Element Discovery Request Response message to the AMF node.

[0221] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be reallocated to the target AMF node.

[0222] Step 508. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 505 to a target AMF node.

[0223] The no-access stratum message is the registration request message in step 501.

[0224] Optionally, the allowed NSSAI include the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAI in step 506. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0225] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 505 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 505, and the registration request message to the target AMF node.

[0226] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include attribute information in step 506.

[0227] Step 509: The target AMF node stores the allowed NSSAI and the service area information corresponding to the allowed NSSAI that is sent by the AMF node, to determine a slice instance for a Petition 870240046306, dated 05 / 31 / 2024, pp. 64 / 101 47 / 77 Session configuration request upon receiving the session configuration request from the terminal device.

[0228] Compared with the modes shown in Figure 4 and Figure 3, in the mode shown in Figure 5, the NSSF node does not directly obtain the permitted NSSAI, and instead, the AMF node obtains the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[0229] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0230] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0231] As shown in Figure 6, an interface is provided between an NSSF node and a UDM device, and the NSSF node and the UDM device can communicate with each other when a terminal device is in a non-roaming scenario. In this scenario, the NSSF node can autonomously query the terminal device's subscription information. In this scenario, a slice-based communication procedure includes the following specific steps.

[0232] Step 601. An AMF node receives a registration request message that is sent via a terminal device and forwarded by a RAN.

[0233] Step 602: The AMF node sends an initial request message to an NSSF node.

[0234] When the AMF node discovers that the AMF node cannot Petition 870240046306, dated 05 / 31 / 2024, pages 65 / 101 48 / 77 To provide a service to the terminal device, or if the AMF cannot determine whether the AMF node can provide a service to the terminal device, the AMF sends the first request message. The first request message carries a SUPI from the terminal device. If the registration request message sent by the terminal device carries the configured NSSAI, the first request message may additionally carry the configured NSSAI. If the registration request message sent by the terminal device does not carry the configured NSSAI, the first request message does not carry the configured NSSAI.

[0235] Step 603: The NSSF node sends a subscription information query request to a UDM device.

[0236] The signature information query request includes the terminal device SUPI that is carried by the first request message that is sent by the AMF node and received by the NSSF node. The NSSF node queries the terminal device signature information from the UDM based on the terminal device SUPI.

[0237] Step 604. The UDM device returns a signature information response message to the NSSF node.

[0238] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the NSSF node, and returns the signature information response message to the NSSF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's signed NSSAI, and may optionally include additional terminal device type information.

[0239] Step 605: The NSSF node sends a response message to the AMF node.

[0240] The reply message carries the service area information corresponding to the first NSSAIs. After receiving the first request message sent by the AMF node, the NSSF node can obtain, based on a match between the NSSAI and a service area obtained from an OAM system and the first NSSAI, the service area information corresponding to the first NSSAI. Optionally, the Petition 870240046306, dated 05 / 31 / 2024, pp. 66 / 101 The 49 / 77 response message may additionally include slice instance identification information corresponding to each S-NSSAI in the first NSSAI, for example, as shown in Table 1 or Table 2.

[0241] Step 606: The AMF node obtains the permitted NSSAIs and the service area information corresponding to the permitted NSSAIs.

[0242] Based on the service area information corresponding to the first NSSAI and carried by the reply message sent by an NSSAI node, the first NSSAI, and the signed NSSAI, the AMF node obtains the allowed NSSAI from the terminal device and the service area information corresponding to the allowed NSSAI. The allowed NSSAI are associated with the first NSSAI, or the allowed NSSAI are associated with the signed NSSAI.

[0243] Step 607: The AMF node sends a network element discovery request to an NRF device.

[0244] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0245] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0246] The content included in the network element discovery request can be further determined based on the content of the response message sent by the NSSF node. When the response message carries the content shown in Table 1, the content that can be carried by the network element discovery request is shown in Table 3. Assuming that a service area of ​​a slice instance having a slice instance identifier of 3 does not include the registration area of Petition 870240046306, dated 05 / 31 / 2024, pp. 67 / 101 50 / 77 terminal device, the network element discovery request only carries information from slice instances having slice instance identifiers 1 and 2. When the response message carries the content shown in Table 2, the content that can be carried by the network element discovery request is shown in Table 4. Assuming that a service area of ​​a slice instance corresponding to slice S-NSSAI 3 does not include the terminal device registration area, the network element discovery request only carries information from slice S-NSSAI 1 and 2.

[0247] Step 608: The NRF device sends a network element discovery request response message to the AMF node.

[0248] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0249] Step 609. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 606 to a target AMF node.

[0250] The no-access stratum message is the registration request message in step 601.

[0251] Optionally, the allowed NSSAIs include the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs in step 607. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0252] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAIs and service area information corresponding to the permitted NSSAIs that are obtained by the AMF node in step 606 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAIs, and the service area information. Petition 870240046306, dated 05 / 31 / 2024, pp. 68 / 101 51 / 77 service corresponding to the permitted NSSAI that are obtained by the AMF node in step 606, and the registration request message for the target AMF node.

[0253] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include the attribute information in step 607.

[0254] Step 610: The target AMF node stores the allowed NSSAI and the service area information corresponding to the allowed NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request when receiving the session configuration request from the endpoint device.

[0255] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0256] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0257] Compared with the mode shown in figure 5, in the mode shown in figure 6, the interface is provided between the NSSF node and the UDM device, the NSSF node can directly obtain the signature information from the terminal device, and the first request message sent by the AMF node to the NSSF node can carry the SUPI of the terminal device.

[0258] As shown in Figure 7, when a terminal device is in a roaming scenario, a slice-based communication procedure includes the following specific steps.

[0259] Step 701: An AMF node sends a message of Petition 870240046306, dated 05 / 31 / 2024, pages 69 / 101 52 / 77 request for subscription information query for a UDM device from an HPLMN.

[0260] After receiving a registration request message that is sent via a terminal device and forwarded by a RAN, the AMF node can query the terminal device's signature information from the UDM device. The signature information query request message carries a SUPI from the terminal device. The terminal device's signature information is queried using the terminal device's SUPI. Optionally, the registration request message can additionally include the HPLMN's configured NSSAI and the VPLMN's configured NSSAI.

[0261] Step 702. The HPLMN UDM device returns a signature information response message to the AMF node.

[0262] The HPLMN UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the AMF node, and returns the signature information response message to the AMF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's HPLMN-signed NSSAI, and may optionally include additional terminal device type information.

[0263] Step 703: The AMF node sends an initial request message to an NSSF node.

[0264] The first request message carries the first NSSAI. The first NSSAI can be obtained by the AMF node based on the HPLMN-configured NSSAI or the VPLMN-configured NSSAI that are carried by the terminal device's signature information and / or the terminal device's registration request message. The first NSSAI are associated with the HPLMN-signed NSSAIs and / or the HPLMN-configured NSSAI. Alternatively, the first NSSAIs may be associated with the HPLMN-signed NSSAIs and / or the VPLMN-configured NSSAIs. For example, the first NSSAI may be an intersection set of the HPLMN-signed NSSAI and the HPLMN-configured NSSAI that are carried by the registration request message. Petition 870240046306, dated 05 / 31 / 2024, pp. 70 / 101 53 / 77 terminal device, either the HPLMN signed NSSAI and the HPLMN configured NSSAI that are carried by the terminal device registration request message, or either the HPLMN signed NSSAI and the VPLMN configured NSSAI that are carried by the terminal device registration request message. Optionally, the first request message additionally carries the terminal device type information.

[0265] Step 704: The NSSF node sends a reply message to the AMF node.

[0266] The reply message carries the service area information corresponding to the second NSSAI. After receiving the first request message sent by the AMF node, based on a match between the VPLMN NSSAI and a service area that is obtained from an OAM system and the first NSSAI, the NSSF node can determine the second NSSAI, and obtain the service area information corresponding to the second NSSAI.

[0267] For example, if the first NSSAI include the HPLMN NSSAI, the NSSF node may first map the HPLMN NSSAI to the corresponding VPLMN NSSAI based on a roaming protocol and then obtain the second NSSAI. The second NSSAI are associated with one or more NSSAI chunks carried by the first NSSAI.

[0268] Optionally, the response message may additionally include the HPLMN NSSAIs that correspond to the VPLMN NSSAIs. For example, this can be shown in Table 6. Table 6 1 S-NSSAI 1 of VPLMN S-NSSAI 1* of HPLMN Service area VPLMN 1 2 S-NSSAI 2 of VPLMN S-NSSAI 2* of HPLMN Service area VPLMN 2 3 S-NSSAI 3 of VPLMN S-NSSAI 3* of HPLMN Service area VPLMN 3

[0269] Step 705: The AMF node obtains the allowed NSSAIs from a VPLMN and the service area information corresponding to NSSAI Petition 870240046306, dated 05 / 31 / 2024, pp. 71 / 101 54 / 77 allowed from VPLMN.

[0270] Based on the service area information corresponding to the second NSSAI and carried by the reply message sent by an NSSAI node, and the second NSSAI, the AMF node obtains the permitted NSSAI from the terminal device's VPLMN and the service area information corresponding to the permitted NSSAI from the VPLMN. The permitted NSSAI from the VPLMN are associated with the second NSSAI.

[0271] Step 706: The AMF node sends a network element discovery request to an NRF device.

[0272] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0273] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0274] The content included in the network element discovery request can be further determined based on the content of the reply message sent by the NSSF node. When the reply message carries the content shown in Table 6, the content that can be carried by the network element discovery request is shown in Table 7. Assuming that a service area of ​​a slice instance corresponding to VPLMN S-NSSAI 3 does not include the terminal device registration area, the network element discovery request carries only information from VPLMN S-NSSAI 1 and VPLMN S-NSSAI 2. Table 7 Petition 870240046306, dated 05 / 31 / 2024, pp. 72 / 101 55 / 77 1 S-NSSAI 1 of VPLMN Service Area VPLMN 1 2 S-NSSAI 2 of VPLMN Service Area VPLMN 2

[0275] Step 707: The NRF device sends a network element discovery request response message to the AMF node.

[0276] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0277] Step 708. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 705 to a target AMF node.

[0278] The no-access stratum message is the registration request message in step 701.

[0279] Optionally, the allowed NSSAI include the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAI in step 706. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0280] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 705 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 705, and the registration request message to the target AMF node.

[0281] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may include Petition 870240046306, dated 05 / 31 / 2024, pp. 73 / 101 56 / 77 additionally the attribute information in step 706.

[0282] Step 709: The target AMF node stores the allowed VPLMN NSSAI and the service area information corresponding to the allowed VPLMN NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request when receiving the session configuration request from the endpoint device.

[0283] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0284] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0285] In the embodiment shown in Figure 7, in step 705, the AMF node determines the permitted VPLMN NSSAI for the terminal device. In another implementation further provided in this embodiment of the present invention, the NSSF node may further determine the permitted VPLMN NSSAI for the terminal device in step 704, and send the permitted VPLMN NSSAI that is determined to the AMF node by means of the response message. For a specific implementation of this procedure, refer to the related steps in the embodiment shown in Figure 4 or Figure 6. The details are not described again in this report.

[0286] As shown in Figure 8, when a terminal device is in a roaming scenario, a slice-based communication procedure includes the following specific steps.

[0287] Step 801. An AMF node receives a registration request message that is sent via a terminal device and that Petition 870240046306, dated 05 / 31 / 2024, pp. 74 / 101 57 / 77 is forwarded by a RAN.

[0288] Step 802: The AMF node sends an initial request message to an NSSF node.

[0289] When the AMF node discovers that the AMF node cannot provide a service to the terminal device, or the AMF cannot determine whether the AMF node can provide a service to the terminal device, the AMF sends the first request message. The first request message carries a SUPI from the terminal device. If the registration request message sent by the terminal device carries the configured NSSAI of an HPLMN or the configured NSSAI of a VPLMN, the first request message may additionally carry the configured NSSAI. If the registration request message sent by the terminal device does not carry the configured NSSAI, the first request message does not carry the configured NSSAI.

[0290] Step 803: The NSSF node sends a subscription information query request to a UDM device of an HPLMN.

[0291] The signature information query request includes the terminal device SUPI that is carried by the first request message that is sent by the AMF node and received by the NSSF node. The NSSF node queries the terminal device signature information from the HPLMN UDM based on the terminal device SUPI.

[0292] Step 804. The HPLMN UDM device returns a signature information response message to the NSSF node.

[0293] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the NSSF node, and returns the signature information response message to the NSSF node. The signature information response message carries the terminal device signature information. The signature information includes the HPLMN-signed NSSAI, and may optionally include additional terminal device type information.

[0294] Step 805: The NSSF node obtains the permitted NSSAI from a VPLMN and the service area information corresponding to the permitted NSSAI from the VPLMN. Petition 870240046306, dated 05 / 31 / 2024, pp. 75 / 101 58 / 77

[0295] The NSSF node can obtain the permitted VPLMN NSSAIs from the terminal device and the service area information corresponding to the permitted VPLMN NSSAIs based on information such as a match between the VPLMN NSSAIs and a service area obtained from an OAM system by the NSSF node, the signed HPLMN NSSAIs carried by the terminal device signature information obtained from the HPLMN UDM, and the configured HPLMN NSSAIs or the configured VPLMN NSSAIs carried by the first request message sent by the AMF node. The permitted VPLMN NSSAIs are associated with the signed HPLMN NSSAIs and / or the configured HPLMN NSSAIs. Alternatively, the permitted VPLMN NSSAIs may be associated with the signed HPLMN NSSAIs and / or the configured VPLMN NSSAIs.For example, before obtaining the permitted NSSAIs from the VPLMN, the NSSF node can map the signed NSSAIs from the HPLMN to the corresponding NSSAIs in the VPLMN based on a roaming protocol. If the first request message carries the configured NSSAIs from the HPLMN, the NSSF node can further map the configured NSSAIs from the HPLMN to the NSSAIs in the VPLMN.

[0296] Step 806: The NSSF node sends a response message to the AMF node.

[0297] The reply message carries the permitted VPLMN NSSAIs and the service area information corresponding to the permitted VPLMN NSSAIs. Optionally, the reply message may additionally include the HPLMN NSSAIs that correspond to the VPLMN NSSAIs. For example, this can be shown in Table 6.

[0298] Step 807: The AMF node sends a network element discovery request to an NRF device.

[0299] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines the attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a device registration area. Petition 870240046306, dated 05 / 31 / 2024, pp. 76 / 101 59 / 77 terminal.

[0300] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0301] The content included in the network element discovery request can be further determined based on the content of the reply message sent by the NSSF node. When the reply message carries the content shown in Table 6, the content that can be carried by the network element discovery request is shown in Table 7. Assuming that a service area of ​​a slice instance corresponding to VPLMN S-NSSAI 3 does not include the terminal device registration area, the network element discovery request carries only the information from VPLMN S-NSSAI 1 and VPLMN S-NSSAI 2.

[0302] Step 808: The NRF device sends a network element discovery request response message to the AMF node.

[0303] The Network Element Discovery Request Response message includes address information for a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0304] Step 809. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 806 to a target AMF node.

[0305] The no-access stratum message is the registration request message in step 801.

[0306] Optionally, the allowed NSSAIs include the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs in step 807. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0307] Optionally, the AMF node can send the message of Petition 870240046306, dated 05 / 31 / 2024, pp. 77 / 101 60 / 77 non-access stratum and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 806 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or identification information of the target AMF node. The RAN node forwards the non-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 806, and the registration request message to the target AMF node.

[0308] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include the attribute information in step 807.

[0309] Step 810: The target AMF node stores the allowed VPLMN NSSAI and the service area information corresponding to the allowed VPLMN NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request when receiving the session configuration request from the endpoint device.

[0310] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0311] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0312] In the embodiment shown in Figure 8, the NSSF node determines the permitted NSSAI of the VPLMN for the terminal device. In another embodiment, the AMF node may additionally determine the NSSAI. Petition 870240046306, dated 05 / 31 / 2024, pp. 78 / 101 61 / 77 of the VPLMN is permitted after step 807 and before step 808. For specific implementation steps, refer to the steps described in the modality shown in Figure 3 or Figure 5. The details are not described again in this report.

[0313] As shown in Figure 9, when a terminal device is in a roaming scenario, a slice-based communication procedure includes the following specific steps.

[0314] Step 901: An AMF node sends a subscription information query request message to a UDM device of an HPLMN.

[0315] After receiving a registration request message that is sent via a terminal device and forwarded by a RAN, the AMF node can query the terminal device's signature information from the UDM device. The signature information query request message carries a SUPI from the terminal device. The terminal device's signature information is queried using the terminal device's SUPI. Optionally, the registration request message can additionally include the HPLMN's configured NSSAI and the VPLMN's configured NSSAI.

[0316] Step 902. The HPLMN UDM device returns a signature information response message to the AMF node.

[0317] The HPLMN UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent by the AMF node, and returns the signature information response message to the AMF node. The signature information response message carries the terminal device signature information. The signature information includes the terminal device's HPLMN-signed NSSAI, and may optionally include additional terminal device type information.

[0318] Step 903: The AMF node sends a first request message to an NSSF node of a VPLMN.

[0319] The first request message ported the first NSSAI. The first NSSAI can be obtained by the AMF node based on the NSSAI configured in the HPLMN or the NSSAI configured in the VPLMN that Petition 870240046306, dated 05 / 31 / 2024, pp. 79 / 101 62 / 77 are carried by the terminal device signature information and / or in the terminal device registration request message. The first NSSAIs are associated with HPLMN signed NSSAIs and / or HPLMN configured NSSAIs. Alternatively, the first NSSAIs may be associated with HPLMN signed NSSAIs and / or VPLMN configured NSSAIs.

[0320] Step 904. The VPLMN NSSF node obtains the second NSSAI.

[0321] After receiving the first request message sent by the AMF node, the VPLMN NSSF node can obtain the second NSSAI based on a match between the VPLMN NSSAI and a service area that is obtained from an OAM system and the first NSSAI. For example, the VPLMN NSSF node can determine, based on the match between the VPLMN NSSAI and a service area, whether the VPLMN NSSAI corresponding to the S-NSSAI indicated by the terminal device's HPLMN-signed NSSAI is supported by the terminal device, in order to obtain the second NSSAI.

[0322] Step 905: The VPLMN NSSF node sends a query request message to an HPLMN NSSF node.

[0323] The query request message ported to the second NSSAI. Optionally, the query request message may additionally include terminal device type information.

[0324] Step 906: The HPLMN NSSF node returns a response query request message to the VPLMN NSSF node.

[0325] The response query request message includes the information corresponding to the second NSSAI. For example, the information corresponding to the second NSSAI may include HPLMN slice instance identification information that corresponds to each SNSSAI in the second NSSAI, and additionally includes the corresponding VPLMN S-NSSAI, as shown in Table 7. Table 7 1 S-NSSAI 1 S-NSSAI 1* HPLMN NSI ID 1* Petition 870240046306, dated 05 / 31 / 2024, pp. 80 / 101 63 / 77 VPLMN HPLMN 2 S-NSSAI 2 of VPLMN S-NSSAI 2* of HPLMN HPLMN NSI ID 2* 3 S-NSSAI 3 of VPLMN S-NSSAI 3* of HPLMN HPLMN NSI ID 3*

[0326] Step 907: The VPLMN NSSF node obtains the permitted VPLMN NSSAIs and the service area information corresponding to the permitted VPLMN NSSAIs.

[0327] The VPLMN NSSF node obtains, based on the second NSSAI and the corresponding second NSSAI information returned from the HPLMN NSSF node, the VPLMN-permitted NSSAI of the terminal device and the service area information corresponding to the VPLMN-permitted NSSAI.

[0328] Step 908: The VPLMN NSSF node sends a response message to the AMF node.

[0329] The reply message ported the permitted VPLMN NSSAIs and the service area information corresponding to the permitted VPLMN NSSAIs. The reply message may additionally include the HPLMN NSSAIs that correspond to the VPLMN NSSAIs, and the slice instance ID information corresponding to each S-NSSAI in the HPLMN NSSAIs. For example, this can be shown in Table 8. Table 8 1 S-NSSAI 1 of VPLMN S-NSSAI 1* of HPLMN VPLMN NSI ID 1 HPLMN NSI ID 1* VPLMN service area 1 2 S-NSSAI 2 of VPLMN S-NSSAI 2* of HPLMN VPLMN NSI ID 2 HPLMN NSI ID 2* VPLMN service area 2 3 S-NSSAI 3 of VPLMN S-NSSAI 3* HPLMN VPLMN NSI ID 3 HPLMN NSI ID 3* VPLMN Service Area 3

[0330] Step 909: The AMF node sends a network element discovery request to an NRF device. Petition 870240046306, dated 05 / 31 / 2024, pages 81 / 101 64 / 77

[0331] Based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained, and the registration area information of the terminal device, the AMF node determines the attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0332] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to the S-NSSAI indicates that a service area of ​​the slice instance corresponding to the S-NSSAI or the slice instance includes the terminal device registration area.

[0333] The content included in the network element discovery request can be further determined based on the content of the reply message sent by the NSSF node. When the reply message carries the content shown in Table 8, the content that can be carried by the network element discovery request is shown in Table 9. Assuming that a service area of ​​a VPLMN slice instance having a slice instance identifier of 3 does not include the terminal device registration area, the network element discovery request carries only the information of a VPLMN slice instance having slice instance identifiers 1 and 2. Table 9 1 VPLMN NSI ID 1 Service area VPLMN 1 2 VPLMN NSI ID 2 Service area VPLMN 2

[0334] Step 910: The NRF device sends a network element discovery request response message to the AMF node.

[0335] The network element discovery request response message includes the address information of a target AMF node. The NRF device determines, based on the content carried by the network element discovery request message, the target AMF node that Petition 870240046306, dated 05 / 31 / 2024, pp. 82 / 101 65 / 77 serves the terminal device. In other words, the terminal device can be relocated to the target AMF node.

[0336] Step 911. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 908 to a target AMF node.

[0337] The no-access stratum message is the registration request message in step 901.

[0338] Optionally, the allowed NSSAI include the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAI in step 909. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0339] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 908 to the target AMF node through the use of a RAN node. For example, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 908, and the registration request message to the target AMF node.

[0340] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include the attribute information in step 909.

[0341] Step 912: The target AMF node stores the allowed VPLMN NSSAI and the service area information corresponding to the allowed VPLMN NSSAI that is sent by the AMF node, to determine a slice instance for a session configuration request when receiving the session configuration request from the endpoint device.

[0342] Optionally, the target AMF node additionally determines, based on the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI that is obtained and the registration area information of the terminal device, the information of Petition 870240046306, dated 05 / 31 / 2024, pp. 83 / 101 66 / 77 attribute of the slice instance corresponding to each S-NSSAI in the allowed NSSAI, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the terminal device's registration area, and indicates to the terminal device, based on the attribute information, whether each S-NSSAI in the allowed NSSAI is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0343] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0344] In the embodiment shown in Figure 9, the NSSF node determines the permitted VPLMN NSSAI for the terminal device. In another embodiment, the AMF node may additionally determine the permitted VPLMN NSSAI after step 908 and before step 909. For specific implementation steps, refer to the steps described in the embodiment shown in Figure 3 or Figure 5. The details are not described again in this report.

[0345] This embodiment of the present invention further provides another possible implementation in this scenario. An interface can be provided between the NSSF node and the HPLMN UDM device, and the NSSF node can directly obtain the roaming terminal device signature information from the HPLMN UDM instead of the AMF node. For specific implementation steps, refer to the related step descriptions in the embodiments shown in Figure 3 and Figure 4. The details are not described again in this report.

[0346] In the modes shown in Figures 3 to 9, the NSSF node can additionally send the pre-configured correspondence between the NSSAIs and a service area to the AMF node. In this case, the reply message sent by the NSSF node to the AMF node does not need to include the service area information supported by the NSSAI, as shown in a procedure in Figure 10.

[0347] Step 1001. An NSSF node sends correspondence between the NSSAIs and a service area to an AMF node.

[0348] The NSSF configures the service area information in a Petition 870240046306, dated 05 / 31 / 2024, pp. 84 / 101 67 / 77 instance slice corresponding to each S-NSSAI in the NSSAI for the AMF node in advance, and the AMF node does not need to obtain the match between the NSSAI and a service area from the NSSF node again after each terminal device sends a registration request.

[0349] For example, the AMF can be notified of the match between NSSAI and a service area when the NSSF node and the AMF node establish a device connection. The match between NSSAI and a service area can indicate the service area information of slice instances matching all S-NSSAI supported in a PLMN, or it can indicate the service area information of a slice instance matching the S-NSSAI supported by the AMF or an AMF group of the AMF.

[0350] For example, NSSAI can be a set of S-NSSAI supported by an NSSF PLMN, or they can be a set of S-NSSAI that is determined based on a network implementation or a network policy that can be provided to the AMF node.

[0351] As shown in Figure 11, when a terminal device is in a non-roaming scenario, a slice-based communication procedure includes the following specific steps.

[0352] Step 1101: An AMF node sends a subscription information query request message to a UDM device.

[0353] After receiving a registration request message that is sent via a terminal device and forwarded by a RAN, the AMF node needs to query the terminal device's signature information from the UDM device. The signature information query request message carries a SUPI from the terminal device. The terminal device's signature information is queried using the terminal device's SUPI. Optionally, the registration request message may additionally include the configured NSSAI.

[0354] Step 1102. The UDM device returns a signature information response message to the AMF node.

[0355] The UDM device obtains the terminal device signature information based on the terminal device SUPI that is sent. Petition 870240046306, dated 05 / 31 / 2024, pages 85 / 101 68 / 77 by the AMF node, and returns the signature information response message to the AMF node. The signature information response message carries the signature information from the terminal device. The signature information includes the signed NSSAI of the terminal device, and may optionally include additional terminal device type information.

[0356] Step 1103: The AMF node sends a first request message to an NSSF node.

[0357] The first request message carries the first NSSAI. The first NSSAI can be obtained by the AMF node based on the configured NSSAI carried by the terminal device's signature information and / or the terminal device's registration request message. The first NSSAI are associated with the signature information and / or the configured NSSAI. The first request message may additionally carry information from the terminal device's registration area.

[0358] Step 1104: The NSSF node obtains the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[0359] The NSSF node can obtain, based on a match between the NSSAI and a service area that is obtained from an OAM system by the NSSF node, the first NSSAI, and other information, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI. The permitted NSSAI are associated with the first NSSAI and can be a universal set or a subset of the first NSSAI.

[0360] The NSSF node determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the attribute information of a slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI includes a registration area of ​​the terminal device.

[0361] Step 1105: The NSSF node sends a network element discovery request message to an NRF device. Petition 870240046306, dated 05 / 31 / 2024, pp. 86 / 101 69 / 77

[0362] The attribute information of a slice instance carried by the network element discovery request or a slice instance corresponding to S-NSSAI indicates that a service area of ​​the slice instance corresponding to S-NSSAI or the slice instance includes the terminal device registration area.

[0363] The content included in the network element discovery request can be further determined based on the content of the response message sent by the NSSF node. When the response message carries the content shown in Table 1, the content that can be carried by the network element discovery request is shown in Table 3. Assuming that a service area of ​​a slice instance having a slice instance identifier 3 does not include the terminal device registration area, the network element discovery request carries only the information of slice instances having slice instance identifiers 1 and 2. When the response message carries the content shown in Table 2, the content that can be carried by the network element discovery request is shown in Table 4.Assuming that a service area of ​​a slice instance corresponding to slice S-NSSAI 3 does not include the terminal device registration area, the network element discovery request will only carry information from slices S-NSSAI 1 and 2.

[0364] Step 1106: The NRF device sends a network element discovery request response message to the NSSF node.

[0365] The Network Element Discovery Request Response message includes the address information of a target AMF node. The NRF device determines, based on the content carried by the Network Element Discovery Request message, the target AMF node that serves the terminal device. In other words, the terminal device can be reallocated to the target AMF node.

[0366] Step 1107: The NSSF node sends a reply message to the AMF node.

[0367] The ported reply message contains the permitted NSSAI and the service area information corresponding to the permitted NSSAI. The ported reply message also contains the address information of the target AMF node. Optionally, the reply message may include Petition 870240046306, dated 05 / 31 / 2024, pp. 87 / 101 70 / 77 additionally slice instance identification information corresponding to each S-NSSAI in the allowed NSSAI, for example, as shown in Table 1 or Table 2. Optionally, the response message may additionally include slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAI in step 1105. Alternatively, the NSSF node sends the attribute information to the AMF node.

[0368] Step 1108. The AMF node sends a no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 1107 to a target AMF node.

[0369] The no-access stratum message is the registration request message in step 1101.

[0370] Optionally, the allowed NSSAI include the slice instance attribute information corresponding to each S-NSSAI in the allowed NSSAI in step 1105. Alternatively, the AMF node sends the attribute information to the target AMF node.

[0371] Optionally, the AMF node can send the no-access stratum message and the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 1107 to the target AMF node through the use of a RAN node. Specifically, the AMF node instructs the RAN node to relocate the registration request message and the address information or the identification information of the target AMF node. The RAN node forwards the no-access stratum message, the permitted NSSAI and service area information corresponding to the permitted NSSAI that are obtained by the AMF node in step 1107, and the registration request message to the target AMF node.

[0372] Optionally, the information that is sent by the AMF node to the target AMF node through the use of the RAN node may additionally include the attribute information in step 1105.

[0373] Step 1109: The target AMF node stores the permitted NSSAI and the service area information corresponding to the permitted NSSAI that is sent by the AMF node, to determine an instance. Petition 870240046306, dated 05 / 31 / 2024, pages 88 / 101 71 / 77 of the slice for a session configuration request when receiving the session configuration request from an endpoint device.

[0374] Optionally, the target AMF node additionally determines, based on the allowed NSSAIs of the terminal device and the service area information corresponding to the allowed NSSAIs that is obtained and the registration area information of the terminal device, the attribute information of the slice instance corresponding to each S-NSSAI in the allowed NSSAIs, where the attribute information is used to indicate whether the service area of ​​the slice instance corresponding to the S-NSSAI includes the registration area of ​​the terminal device, and indicates to the terminal device based on the attribute information whether each S-NSSAI in the allowed NSSAIs is sustained or left in the registration area. For example, this can be indicated in Table 5.

[0375] For example, the indication can be carried by a register reply message sent by the AMF to the terminal device through the use of the RAN node.

[0376] This embodiment of the present invention further provides another possible implementation in this scenario. An interface can be provided between the NSSF node and the UDM device, and the NSSF node can directly obtain the roaming terminal device signature information from the HPLMN UDM instead of the AMF node. For specific implementation steps, refer to the related step descriptions in the embodiments shown in Figure 3 and Figure 4. The details are not described again in this report.

[0377] Based on the same technical idea, Figure 12 shows a slice-based communication device, according to an embodiment of the present invention. The device can perform a slice-based communication procedure.

[0378] As shown in Figure 12, the apparatus specifically includes: a processing unit 1201 and a transceiver unit 1202, wherein the processing unit 1201 is configured to control the transceiver unit 1202 to send an initial request message to an NSSF node; and Petition 870240046306, dated 05 / 31 / 2024, pages 89 / 101 72 / 77 the processing unit 1201 is additionally configured to: control the transceiver unit 1202 to receive a reply message from the NSSF node, and obtain, based on the reply message, allowed NSSAI network slice selection assistance information from a terminal device and service area information corresponding to the allowed NSSAI.

[0379] In addition, processing unit 1201 and transceiver unit 1202 can additionally perform several other AMF node operations in the previous modes. The details are not described again.

[0380] Based on the same technical idea, Figure 13 shows a slice-based communication device, according to an embodiment of the present invention. The device can perform a slice-based communication procedure.

[0381] As shown in Figure 13, the device specifically includes: a processing unit 1301 and a transceiver unit 1302, wherein the processing unit 1301 is configured to control the transceiver unit 1302 to receive a first request message from an AMF node; and the processing unit 1301 is further configured to control the transceiver unit 1302 to send a reply message to the AMF node, wherein the reply message carries NSSAI network slice selection assistance information, or the NSSAI and service area information corresponding to the NSSAI.

[0382] In addition, processing unit 1301 and transceiver unit 1302 can additionally perform several other NSSF node operations in the previous modes. The details are not described again.

[0383] Based on the same technical idea, Figure 14 shows a 1400 slice-based communications device, according to an embodiment of the present invention. The 1400 slice-based communications device can perform the steps or functions performed by the AMF node in previous embodiments. The slice-based communications device Petition 870240046306, dated 05 / 31 / 2024, pages 90 / 101 73 / 77 The 1400 may include: a transceiver 1401, a processor 1402, and a memory 1403. The processor 1402 is configured to control the operations of the communications device based on slice 1400. The memory 1403 may include read-only memory and random-access memory, and store an instruction that can be executed by the processor 1402 and data. Components such as the transceiver 1401, the processor 1402, and the memory 1403 are connected through the use of a bus 1409. The bus 1409 may additionally include a power supply bus, a control bus, and a status signal bus in addition to a data bus. However, for the purposes of clear descriptions, various buses are all marked as bus 1409 in the figure. The 1401 transceiver can be a transceiver machine, and may include both a transmitter and a receiver.

[0384] A slice-based communications method disclosed in embodiments of the present invention can be applied to or implemented by the 1402 processor.

[0385] Processor 1402 is configured to read the code in memory 1403 to execute a slice-based communication procedure.

[0386] For example, optionally, when obtaining, based on the response message, the permitted NSSAI of the terminal device and the service area information corresponding to the permitted NSSAI, processor 1402 is specifically configured to: When the reply message carries the permitted NSSAI and the service area information corresponding to the permitted NSSAI, obtain the permitted NSSAI and the service area information corresponding to the permitted NSSAI from the reply message; or when the reply message carries the permitted NSSAI, obtain the permitted NSSAI from the reply message, and obtain, based on a match between the NSSAI and a service area, the service area information corresponding to the permitted NSSAI; or when the reply message carries the first NSSAI and the service area information corresponding to the first NSSAI, determine, based on the first NSSAI and the service area information... Petition 870240046306, dated 05 / 31 / 2024, pp. 91 / 101 74 / 77 service corresponding to the first NSSAI, the permitted NSSAI and the service area information corresponding to the permitted NSSAI.

[0387] Optionally, the 1402 processor is additionally configured to: Consult the terminal device's signature information, where the signature information includes the terminal device's signed NSSAIs, the first ported request message, the first NSSAIs, and the first NSSAIs associated with the signed NSSAIs.

[0388] Optionally, the 1402 processor is additionally configured to: To control transceiver 1401 to receive a registration request message from the terminal device, where the registration request message carries the configured NSSAI, the first request message carries the first NSSAI and the first NSSAI are associated with the configured NSSAI, or the first NSSAI are associated with the signed NSSAI and the configured NSSAI.

[0389] Based on the same technical idea, Figure 15 shows a 1500-slice-based communications device according to one embodiment of the present invention. The 1500-slice-based communications device can perform the steps or functions performed by the NSSF node in previous embodiments. The 1500-slice-based communications device may include: a transceiver 1501, a processor 1502, and a memory 1503. The processor 1502 is configured to control the operations of the 1500-slice-based communications device. The memory 1503 may include a read-only memory and a random access memory, and store an instruction and data that can be executed by the processor 1502. The components, such as the transceiver 1501, the processor 1502, and the memory 1503, are connected by means of a bus 1509.The 1509 bus may additionally include a power supply bus, a control bus, and a status signal bus, in addition to a data bus. However, for the purposes of clear descriptions, several buses are marked as the 1509 bus in the figure. The 1501 transceiver may be a transceiver machine and may include a transmitter and a receiver. Petition 870240046306, dated 05 / 31 / 2024, pages 92 / 101 75 / 77

[0390] A slice-based communications method disclosed in embodiments of the present invention can be applied to or implemented by the 1502 processor.

[0391] Processor 1502 is configured to read the code in memory 1503 to execute a slice-based communication procedure.

[0392] For example, optionally, NSSAI are the permitted NSSAI.

[0393] Optionally, the first request message carries the first NSSAI and the allowed NSSAI are associated with the first NSSAI; and the first NSSAI are associated with the signed NSSAI or the first NSSAI are associated with the configured NSSAI or the first NSSAI are associated with the signed NSSAI and the configured NSSAI; or the first request message carries the identification information of a terminal device; and processor 1502 is additionally configured to: query the terminal device's signature information based on the identification information, where the signature information includes the terminal device's signed NSSAIs and the allowed NSSAI are associated with the signed NSSAI.

[0394] Optionally, the first request message ported the first NSSAI, and the NSSAI are the first NSSAI; The first NSSAI are associated with the signed NSSAI, or the first NSSAI are associated with the configured NSSAI, or the first NSSAI are associated with both the signed and configured NSSAI. The first request message carries the identification information of a terminal device; and processor 1502 is additionally configured to: Consult the terminal device's signature information based on the identification information, where the signature information includes the terminal device's signed NSSAIs, and the first NSSAIs are associated with the signed NSSAIs.

[0395] A person skilled in the art should understand that embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, embodiments Petition 870240046306, dated 05 / 31 / 2024, pp. 93 / 101 76 / 77 of the present invention may use a form of hardware-only embodiments, software-only embodiments, or embodiments with a combination of software and hardware. Furthermore, embodiments of the present invention may use a form of a computer program product that is implemented on one or more computer-usable storage media (including but not limited to disk memory, a CD-ROM, optical memory, and the like) that includes computer-usable program code.

[0396] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the method, the device (system), and the computer program product, according to the embodiments of the present invention. It should be understood that the computer program instructions can be used to implement each process and / or each block in the flowcharts and / or block diagrams and a combination of a process and / or a block in the flowcharts and / or block diagrams.These computer program instructions can be provided by a general-purpose computer, a dedicated computer, an embedded processor, or a processor of any other programmable data processing device to generate a machine, so that the instructions executed by a computer or a processor of any other programmable data processing device generate a device to implement a specific function in one or more processes in flowcharts and / or in one or more blocks in block diagrams.

[0397] These computer program instructions can be stored in computer-readable memory that can instruct the computer or any other programmable data processing device to work in a specific way, so that the instructions stored in computer-readable memory generate an artifact that includes an instruction device. The instruction device implements a specific function in one or more processes in flowcharts and / or in one or more blocks in block diagrams.

[0398] These computer program instructions can be loaded into a computer or other programmable data processing device, so that a series of operations and steps are Petition 870240046306, dated 05 / 31 / 2024, pages 94 / 101 77 / 77 performed on the computer or other programmable device, thus generating computer-implemented processing. Therefore, the instructions executed on the computer or other programmable device provide the steps to implement a specific function in one or more processes in flowcharts and / or in one or more blocks in block diagrams.

[0399] Obviously, a person skilled in the art may make various modifications and variations in embodiments of the present invention without departing from the spirit and scope of the present invention. The present invention is intended to cover such modifications and variations provided that they are within the scope of protection defined by the following claims and their equivalent technologies. Petition 870240046306, dated 05 / 31 / 2024, pages 95 / 101

Claims

1 / 5 CLAIMS 1. A slice-based communications method, CHARACTERIZED in that the method is performed by an access and mobility management function node (AMF) in a visited public terrestrial mobile network (VPLMN), and comprising: receiving (801) a registration request message from a terminal device that is roaming in the VPLMN through a radio access network node (RAN) in the VPLMN; sending (802) a first request message to a network slice selection function node (NSSF) in the VPLMN, wherein the first request message comprises terminal device identification information;and receive (806) a reply message from the NSSF node, wherein the reply message comprises network slice selection assistance information from the terminal device's allowed VPLMN NSSAI and additionally comprises the terminal device's HPLMN domestic public land mobile network NSSAI that corresponds to the terminal device's allowed VPLMN NSSAI.; 2. Method, according to claim 1, CHARACTERIZED in that it further comprises: receiving a correspondence between NSSAI and an NSSF service area; obtaining, based on the NSSAI VPLMN allowed from the reply message and based on the correspondence, service area information corresponding to the NSSAI VPLMN allowed.

3. Method, according to claim 1 or 2, CHARACTERIZED in that the response message additionally comprises slice instance identification information corresponding to each single network slice selection assistance information S-NSSAI in the permitted NSSAI VPLMN.

4. Method, according to any one of claims 1 to 3, CHARACTERIZED in that it further comprises: obtaining registration area information from the terminal device; and determining a first S-NSSAI that is an S-NSSAI of the permitted NSSAI Petition 870240046306, dated 05 / 31 / 2024, page 96 / 101 2 / 5 VPLMN that corresponds to a service area comprising the registration area of ​​the terminal device.

5. Method, according to claim 4, CHARACTERIZED in that it further comprises: determining, based on the permitted NSSAI VPLMN of the terminal device and the service area information corresponding to the permitted NSSAI that is obtained and the registration area information of the terminal device, attribute information of a slice instance corresponding to each S-NSSAI in the permitted NSSAI VPLMN, wherein the attribute information is used to indicate whether a service area of ​​the slice instance corresponding to the S-NSSAI comprises a registration area of ​​the terminal device.

6. Method according to claim 5, CHARACTERIZED in that the method further comprises: sending (807) a second request message to an NRF network repository function device in the VPLMN, wherein the second request message comprises the first S-NSSAI or slice instance identification information corresponding to the first S-NSSAI; receiving (808) address information of a target AMF node in the VPLMN from the NRF device; and sending (809) the permitted VPLMN NSSAI and service area information corresponding to the permitted VPLMN NSSAI to the target AMF node based on the target AMF node address information.

7. Method, according to claim 6, CHARACTERIZED in that it further comprises: sending slice instance identification information corresponding to each S-NSSAI VPLMN in the allowed NSSAI VPLMNs to the target AMF node.

8. Method according to claim 6, CHARACTERIZED in that it further comprises: sending the attribute information to the target AMF node.

9. Method, according to any one of claims 1 to 8, CHARACTERIZED in that the response message comprises Petition 870240046306, dated 05 / 31 / 2024, p. 97 / 101 3 / 5 additionally slice instance identification information corresponding to each S-NSSAI in the HPLMN NSSAI.

10. Slice-based communications method, CHARACTERIZED in that the method is performed by a network slice selection function node NSSF within a visited public land mobile network VPLMN, and comprising: receiving (802) a first request message from an access and mobility management function node AMF within the VPLMN, wherein the first request message comprises identification information of a terminal device that is roaming in the VPLMN via a radio access network node RAN in the VPLMN; and sending (806) a reply message to the AMF node, wherein the reply message carries network slice selection assistance information NSSAI VPLMN permitted of the terminal device and additionally comprises NSSAI of the domestic public land mobile network HPLMN of the terminal device that corresponds to the NSSAI VPLMN permitted of the terminal device.

11. Method, according to claim 10, CHARACTERIZED in that it further comprises: sending a correspondence between NSSAI and a service area to the AMF node; wherein the NSSAI VPLMN allowed in the reply message and the correspondence are used for the AMF node to obtain service area information corresponding to the NSSAI VPLMN allowed.

12. Method, according to claim 10 or 11, CHARACTERIZED in that the response message additionally carries slice instance identification information corresponding to each single network slice selection assistance information S-NSSAI in the permitted NSSAI VPLMN.

13. Method, according to any one of claims 10 to 12, CHARACTERIZED in that the response message additionally comprises slice instance identification information corresponding to each S-NSSAI in the HPLMN NSSAI.

14. Slice-based communications device in a public visited terrestrial mobile network (VPLMN), CHARACTERIZED in that it comprises: a transceiver (1401) and a processor (1402), wherein the processor is configured to control the transceiver to receive a registration request message from a terminal device that is roaming in the VPLMN through a radio access network node (RAN) in the VPLMN; the processor is further configured to control the transceiver to send a first request message to a network slice selection function node (NSSF) in the VPLMN, wherein the first request message comprises terminal device identification information;and the processor is additionally configured to: control the transceiver to receive a reply message from the NSSF node, wherein the reply message comprises network slice selection assistance information for the terminal device's allowed NSSAI VPLMN and additionally comprises the terminal device's HPLMN domestic public land mobile network NSSAI that corresponds to the terminal device's allowed NSSAI VPLMN.

15. Device according to claim 14, CHARACTERIZED in that the processor is further configured to: control the transceiver to receive a match between NSSAI and a service area from the NSSF; obtain, based on the NSSAI VPLMN allowed from the reply message and based on the match, service area information corresponding to the NSSAI VPLMN allowed.

16. Slice-based communications device within a visited public terrestrial mobile network VPLMN, CHARACTERIZED in that it comprises: a transceiver (1501) and a processor (1502), wherein the processor is configured to control the transceiver to receive a first request message from an access and mobility management function node AMF within the VPLMN, wherein the first request message comprises identification information of a terminal device that is roaming in the VPLMN through a node of Petition 870240046306, dated 05 / 31 / 2024, p.99 / 101 5 / 5 radio access network RAN ​​in the VPLMN; and the processor is additionally configured to control the transceiver to send a reply message to the AMF node, wherein the reply message carries network slice selection assistance information NSSAI VPLMN allowed from the terminal device and additionally includes NSSAI domestic public land mobile network HPLMN of the terminal device that corresponds to the NSSAI VPLMN allowed from the terminal device.

17. Device according to claim 16, CHARACTERIZED in that the processor is additionally configured to: control the transceiver to send a correspondence between NSSAI and a service area to the AMF node; wherein the NSSAI VPLMN allowed in the reply message and the correspondence are used for the AMF node to obtain service area information corresponding to the NSSAI VPLMN allowed.

18. Computer-readable media, CHARACTERIZED in that it comprises instructions which, when executed by a computer, cause the computer to perform the method as defined in any one of claims 1 to 9.

19. Computer-readable media, CHARACTERIZED in that it comprises instructions which, when executed by a computer, cause the computer to perform the method as defined in any one of claims 10 to 13. Petition 870240046306, dated 05 / 31 / 2024, pp. 100 / 101

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