# US 2019/0246318 A1 · Method for determining emm mode in wireless communication system, and apparatus therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246318 A1 - Document ID: US20190246318A1 - Status: Published application - Kind: A1 - Application number: 16/338,666 - Filed: 2017-10-27 - Published: 2019-08-08 - Earliest claimed: 2016-10-30 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Taehun KIM; Sangwook HAN - Web page: https://patentgrep.com/patent/US20190246318A1 ## CPC - H04W 36/0055: {Transmission or use of information for re-establishing the radio link} - H04W 48/12: using downlink control channel - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 8/08: Mobility data transfer - H04W 48/08: Access restriction or access information delivery, e.g. discovery data delivery (signalling during connection H04W76/00) - H04W 48/20: Selecting an access point - H04W 76/19: Connection re-establishment - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 60/04: using triggered events - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method and a device for determining an evolved packet system (EPS) mobility management (EMM) mode in a wireless communication system are disclosed. More specifically, a method for determining, by a user equipment (UE), an EMM mode in a wireless communication system includes receiving, by the UE in an EMM-IDLE mode with suspend indication, from a base station a system information block (SIB) including information that a serving cell of the UE does not support user plane (UP) cellular Internet of Things (CIoT) EPS optimization; storing the information that the serving cell does not support the UP CIoT EPS optimization; and maintaining the EMM-IDLE mode with suspend indication if a procedure using an initial non-access stratum (NAS) message is not triggered and the serving cell is changed to a cell supporting the UP CIoT EPS optimization. ## Claims ### Claim 1 A method for determining, by a user equipment (UE), an evolved packet system (EPS) mobility management (EMM) mode in a wireless communication system, the method comprising: receiving, by the UE in an EMM-IDLE mode with suspend indication, from a base station a system information block (SIB) including information that a serving cell of the UE does not support user plane (UP) cellular Internet of Things (CIoT) EPS optimization; storing the information that the serving cell does not support the UP CIoT EPS optimization; and maintaining the EMM-IDLE mode with suspend indication if a procedure using an initial non-access stratum (NAS) message is not triggered and the serving cell is changed to a cell supporting the UP CIoT EPS optimization. ### Claim 2 (depends on 1) The method of claim 1, wherein if the procedure using the initial NAS message is not triggered and the serving cell is changed to the cell supporting the UP CIoT EPS optimization, the information that the serving cell does not support the UP CIoT EPS optimization is deleted. ### Claim 3 (depends on 1) The method of claim 1, further comprising, after the procedure using the initial NAS message is triggered, entering a NAS layer of the UE in the EMM-IDLE mode without suspend indication. ### Claim 4 (depends on 3) The method of claim 3, wherein an access stratum (AS) layer of the UE stores the information that the serving cell does not support the UP CIoT EPS optimization. ### Claim 5 (depends on 4) The method of claim 4, wherein even if the NAS layer of the UE requests the AS layer of the UE to resume a radio resource control (RRC) connection while the information that the serving cell does not support the UP CIoT EPS optimization is stored, the AS layer of the UE sends a RRC connection request message to the base station. ### Claim 6 (depends on 5) The method of claim 5, wherein if the AS layer of the UE receives from the base station a RRC connection setup message as a response to the RRC connection request message, the AS layer of the UE transmits a request of the initial NAS message to the NAS layer of the UE. ### Claim 7 (depends on 6) The method of claim 6, wherein the request of the initial NAS message is an indication that a RRC connection resume has fallbacked. ### Claim 8 (depends on 6) The method of claim 6, wherein if the NAS layer of the UE receives the request of the initial NAS message, the NAS layer of the UE sends the initial NAS message to the AS layer of the UE and enters the EMM-IDLE mode without suspend indication. ### Claim 9 (depends on 3) The method of claim 3, wherein the AS layer of the UE delivers to the NAS layer of the UE the information that the serving cell does not support the UP CIoT EPS optimization. ### Claim 10 (depends on 9) The method of claim 9, wherein the NAS layer of the UE stores the information that the serving cell does not support the UP CIoT EPS optimization. ### Claim 11 A user equipment (UE) for determining an evolved packet system (EPS) mobility management (EMM) mode in a wireless communication system, the UE comprising: a communication module configured to transmit and receive a signal; and a processor configured to control the communication module, wherein the processor is configured to: receive, by the UE in an EMM-IDLE mode with suspend indication, from a base station a system information block (SIB) including information that a serving cell of the UE does not support user plane (UP) cellular Internet of Things (CIoT) EPS optimization; store the information that the serving cell does not support the UP CIoT EPS optimization; and maintain the EMM-IDLE mode with suspend indication if a procedure using an initial non-access stratum (NAS) message is not triggered and the serving cell is changed to a cell supporting the UP CIoT EPS optimization.