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; receiving by the UE in an EMM-IDLE mode with suspend indication, from a base station the SIB including information that a serving cell of the UE does support the UP CIoT EPS optimization; maintaining the EMM-IDLE mode with suspend indication if a procedure using an initial non-access stratum, NAS, message is not triggered based on the SIB including information that a serving cell of the UE does not support the UP CIoT EPS optimization, the serving cell is changed to a cell supporting the UP CIoT EPS optimization, and the information that the serving cell does not support the UP CIoT EPS optimization is deleted; after the procedure using the initial NAS message is triggered based on the SIB including information that a serving cell of the UE does support the UP CIoT EPS optimization, entering a NAS layer of the UE in the EMM-IDLE mode without suspend indication; wherein an access stratum, AS, layer of the UE stores the information that the serving cell does not support the UP CIoT EPS optimization, 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, 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. 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; receiving by the UE in an EMM-IDLE mode with suspend indication, from a base station the SIB including information that a serving cell of the UE does support the UP CIoT EPS optimization; maintaining the EMM-IDLE mode with suspend indication if a procedure using an initial non-access stratum, NAS, message is not triggered based on the SIB including information that a serving cell of the UE does not support the UP CIoT EPS optimization, the serving cell is changed to a cell supporting the UP CIoT EPS optimization, and the information that the serving cell does not support the UP CIoT EPS optimization is deleted; after the procedure using the initial NAS message is triggered based on the SIB including information that a serving cell of the UE does support the UP CIoT EPS optimization, entering a NAS layer of the UE in the EMM-IDLE mode without suspend indication; wherein an access stratum, AS, layer of the UE stores the information that the serving cell does not support the UP CIoT EPS optimization, 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, 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.