Abstract: According to one embodiment of this specification, there is provided a method performed by a user equipment (UE). The method may comprise: receiving a registration reject message including first radio access technology (RAT) utilization control information indicating that an access technology of a cell on which a registration request message is received is restricted; storing the received first RAT utilization control information together with a public land mobile network (PLMN) identity of a current PLMN in a list of “PLMNs with associated RAT restrictions”; receiving a configuration update command message including second RAT utilization control information; determining a length of the second RAT utilization control information; and if the length is zero, removing the stored first RAT utilization control information.

Abstract: According to one embodiment of this specification, there is provided an operation method of user equipment (UE). The method may comprise: triggering a tracking area update (TAU) procedure when an unavailability period has ended and a discontinuous coverage maximum time offset timer has expired; starting a first timer at completion of the tracking area update procedure if the UE has included unavailability information and has not included a start of the unavailability period in a tracking area update request message; and upon coming out of the unavailability period, activating an access stratum (AS) layer.

Abstract: According to one embodiment of this specification, there is provided an operation method of user equipment (UE). The method may comprise: transmitting an attach request message; and receiving a response message. If the response message is an attach accept message and if the attach accept includes radio access technology (RAT) utilization control information, the RAT utilization control information may be for current PLMN and its equivalent PLMN. The method may further comprise: if the response message is an attach reject message, if the attach reject message includes the RAT utilization control information and if the attach reject message is successfully integrity checked, storing the RAT utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated RAT restrictions.

Abstract: Provided are a method and apparatus for operating a terminal based on capability in a wireless communication system. A terminal may receive a master information block (MIB) including first barring information. After receiving the MIB, the terminal may receive a system information block 1 (SIB1) including second barring information and third barring information. Further, the terminal may consider a first cell as an acceptable cell, based on the first barring information, the second barring information and the third barring information.

Abstract: According to one embodiment of this specification, there is provided a method performed by a user equipment (UE). The method may comprise: receiving a REGISTRATION ACCEPT message or a CONFIGURATION UPDATE COMMAND message including on-demand Network Slice Selection Assistance Information (NSSAI) and a slice deregistration inactivity timer. The on-demand NSSAI may include one or more on-demand single NSSAIs (S-NSSAIs). The method may further comprise: starting the slice deregistration inactivity timer for a first on-demand S-NSSAI, if a protocol data unit (PDU) session associated with the first on-demand S-NSSAI is released, if there is no established user plane resources of a multi-access (MA) PDU session associated with the first on-demand S-NSSAI and if there is no PDU session associated with the first on-demand S-NSSAI.

Abstract: Provided are a method and apparatus for small data transmission in a wireless communication system. A terminal may initiate a small data transmission (SDT) procedure. The terminal may perform a first random access (RA) procedure, while the initiated SDT procedure is ongoing and the first RA procedure is triggered by uplink data arrival. The first RA procedure may be performed using first random access channel (RACH) resources, and the first RACH resources are not configured for SDT.

Abstract: According to one embodiment of this specification, there is provided a method performed by a user equipment (UE). The method may comprise: starting a slice deregistration inactivity timer if a handover to other access is successfully completed and if there is no established protocol data unit (PDU) session including any multi access (MA) PDU session associated with a Single Network Slice Selection Assistance Information (S-NSSAI) over a corresponding access type; upon expiry of the slice deregistration inactivity timer, locally removing the S-NSSAI from allowed NSSAI over the corresponding access type; and upon expiry of the slice deregistration inactivity timer, deleting an entry including a replaced S-NSSAI or an alternative S-NSSAI stored in an alterative NSSAI.

Abstract: According to one embodiment of this specification, there is provided a method performed by a terminal. The method may comprise: transmitting a first message. The first message may include a Protocol Data Unit (PDU) session release request message or a PDU session modification request message. The PDU session modification request message may include a PS data off status which is set to ‘deactivated’. The first message may be transmitted respectively according to one or more situations. The one or more situations may relate to Single Network Slice Selection Assistance Information (S-NSSAI).

Abstract: According to one embodiment of this specification, there is provided an operation method of user equipment (UE). The method may comprise: transmitting an attach request message; and receiving a response message. If the response message is an attach accept message and if the attach accept includes radio access technology (RAT) utilization control information, the RAT utilization control information may be for current PLMN and its equivalent PLMN. The method may further comprise: if the response message is an attach reject message, if the attach reject message includes the RAT utilization control information and if the attach reject message is successfully integrity checked, storing the RAT utilization control information together with a PLMN identity of a current PLMN in a list of PLMNs with associated RAT restrictions.

Abstract: According to one embodiment of this specification, there is provided a method. The method may comprise: receiving a Registration Accept message or UE Configuration Update Command message. The Registration Accept message or UE Configuration Update Command message includes at least one of a slice deregistration inactivity timer and validity time for one or more Single Network Slice Selection Assistance Information (S-NSSAI). The method may comprise: starting a first timer based on the slice deregistration inactivity timer. If the first timer expires, the UE locally removes the S-NSSAI from the Allowed NSSAI. If UE does not trigger Mobility Registration Update and Allowed NSSAI becomes empty after expiry of the validity time, then the UE enters deregistered state implicitly.