# US 2018/0324761 A1 · Communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324761 A1 - Document ID: US20180324761A1 - Status: Published application - Kind: A1 - Application number: 15/772,900 - Filed: 2016-11-08 - Published: 2018-11-08 - Earliest claimed: 2015-11-10 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Genadi VELEV; Iskren IANEV; Toshiyuki TAMURA - Web page: https://patentgrep.com/patent/US20180324761A1 ## CPC - H04W 72/04: Wireless resource allocation - H04W 48/18: Selecting a network or a communication service - H04W 8/06: Registration at serving network Location Register, VLR or user mobility server - H04W 8/18: Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data - H04W 84/00: Network topologies - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The invention describes a method for detecting an inability to serve a UE in the selected serving node due to mismatch between the UE's DCN-related indication and the UE's DCN-related subscription and/or the UE's capabilities and/or due to serving node congestion. The method allows to update the UE's DCN configuration information, so that the UE can be assigned to an appropriate DCN during the next RRC/NAS request procedure. ## Claims ### Claim at position 1 1-6. (canceled) ### Claim 7 A communication method for selecting a network resource, comprising: receiving a Non-Access Stratum (NAS) message including information for selecting a network slice, from a mobile terminal via an access network node; retrieving subscription information from a core network control plane network function; determining whether the information for selecting the network slice and relevant data from the subscription information are matched or not; and rejecting the NAS message with a cause corresponding to unmatching between the information for selecting the network slice and the relevant data from the subscription information, wherein the cause indicates that the network slice is not allowed to access. ### Claim 8 (depends on 7) The communication method according to claim 7, further comprising: detecting temporary unavailability of the network slice; and rejecting the NAS message with a cause indicating that the network slice is temporarily unavailable. ### Claim 9 (depends on 7) The communication method according to claim 7, wherein the rejecting is performed by sending to the mobile terminal a message including information for selecting another network slice other than the network slice indicated by the information included in the message from the mobile terminal. ### Claim 10 A communication method for a mobile terminal, comprising: sending a Non-Access Stratum (NAS) message including information for selecting a first network slice, towards an access network node; receiving a NAS reject message with a cause indicating that the information related to the first network slice is not allowed, from a core network node via the access network node; updating the information for selecting the first network slice to information for selecting a second network slice; and sending another NAS message including the updated information for selecting the second network slice towards the access network node. ### Claim 11 (depends on 10) The communication method according to claim 10, wherein the NAS reject message includes the information for selecting the second network slice. ### Claim 12 A core network node for selecting a network slice, comprising: a receiver configured to receive a Non-Access Stratum (NAS) message including information for selecting the network slice, from a mobile terminal via an access network node; and at least one processor configured to: retrieve subscription information from a core network control plane network function; determine whether the information for selecting the network slice and relevant data from the subscription information are matched or not; and reject the NAS message with a cause corresponding to unmatching between the information for selecting the network slice and the relevant data from the subscription information, wherein the cause indicates that the network slice is not allowed to access. ### Claim 13 (depends on 12) The core network node according to claim 12, the at least one processor further being configured to detect temporary unavailability of the network slice, and wherein the at least one processor is further configured to reject the NAS message with a cause indicating that the network slice is temporarily unavailable. ### Claim 14 (depends on 12) The core network node according to claim 12, further comprising: a sender configured to send to the mobile terminal a message including information for selecting another network slice other than the network slice indicated by the information included in the message from the mobile terminal. ### Claim 15 A mobile terminal, comprising: a first sender configured to send a Non-Access Stratum (NAS) message including information for selecting a first network slice, towards an access network node; a receiver configured to receive a NAS reject message with a cause indicating that the information related to the first network slice is not allowed, from a core network node via the access network node; at least one processor configured to update the information for selecting the first network slice to information for selecting a second network slice; and a second sender configured to send another NAS message including the updated information for selecting the second network slice, towards the access network node. ### Claim 16 (depends on 15) The mobile terminal according to claim 15, wherein the NAS reject message includes the information for selecting the second network slice. ### Claim 17 (depends on 7) A non-transitory computer readable recording medium storing a computer program comprising computer implementable instructions, the computer program causing a programmable communications device to perform the method of claim 7. ### Claim 18 A system comprising a core network node for selecting a network slice and a mobile terminal, wherein the core network node comprises: a receiver configured to receive a Non-Access Stratum (NAS) message including information for selecting a first network slice, from a mobile terminal via an access network node; and at least one processor configured to: retrieve subscription information from a core network control plane network function; determine whether the information for selecting the first network slice and relevant data from the subscription information are matched or not; and reject the NAS message with a cause corresponding to unmatching between the information for selecting the first network slice and the relevant data from the subscription information, wherein the cause indicates that the network slice is not allowed to access, wherein the mobile terminal comprises: a first sender configured to send a Non-Access Stratum (NAS) message including information for selecting the first network slice, towards an access network node; a receiver configured to receive a NAS reject message with a cause indicating that the information related to the first network slice is not allowed, from a core network node via the access network node; at least one processor configured to update the information for selecting the first network slice to information for selecting a second network slice; and a second sender configured to send another NAS message including the updated information for selecting the second network slice, towards the access network node.