A system described herein may provide a technique for the predictive determination of regions, such as registration areas associated with a wireless network, with respect to a User Equipment (“UE”) that registers with the wireless network. Such registration areas may be associated with different services, Quality of Service (“QoS”) parameters, network slices, or the like. When registering with the wireless network, the UE may receive an indication of a registration area that includes multiple tracking areas, which include a tracking area in which the UE is currently located and one or more other tracking areas in which the UE is likely to enter, as predicted based on one or more artificial intelligence/machine learning (“AI/ML”) models. The prediction may be based on the current location of the UE, UE attributes or parameters, and/or historical location information associated with the UE and/or other UEs.

A method of supporting inter-system mobility of a first entity includes receiving a create session request message including information about an Access Point Name (APN), for which a user equipment requests a packet data network (PDN) connection, subscriber identification information of the user equipment, and a field indicating capability information of the user equipment about slice identification information, determining, based on the create session request message, whether movement to a 5G system (5GS) is required for the PDN connection, transmitting, based on a result of the determining, to a second entity, a subscriber information request including the subscriber identification information and the APN information, receiving, from the second entity, a response to the subscriber information request including identification information of one or more subscribed network slices corresponding to the subscriber identification information, and providing, to the user equipment, at least one piece of identification information of the one or more subscribed network slices.

A method of supporting inter-system mobility of a first entity includes receiving a create session request message including information about an Access Point Name (APN), for which a user equipment requests a packet data network (PDN) connection, subscriber identification information of the user equipment, and a field indicating capability information of the user equipment about slice identification information, determining, based on the create session request message, whether movement to a 5G system (5GS) is required for the PDN connection, transmitting, based on a result of the determining, to a second entity, a subscriber information request including the subscriber identification information and the APN information, receiving, from the second entity, a response to the subscriber information request including identification information of one or more subscribed network slices corresponding to the subscriber identification information, and providing, to the user equipment, at least one piece of identification information of the one or more subscribed network slices.

The present disclosure provides a method of reporting radio link failure information, a method of obtaining radio link failure information, a terminal, and a network side device. The method of reporting radio link failure information, applied to a terminal, includes: recording radio link failure (RLF) information, in a process of the terminal performing a radio resource control (RRC) connection re-establishment or a RRC connection establishment, the RLF information including at least one of: a tracking area code (TAC), a tracking area identifier (TAI) and a system identifier of a terminal access cell, wherein the RLF information is related to a time of RRC connection establishment or RRC connection re-establishment; reporting the RLF information to a network side device.

The present disclosure provides a method of reporting radio link failure information, a method of obtaining radio link failure information, a terminal, and a network side device. The method of reporting radio link failure information, applied to a terminal, includes: recording radio link failure (RLF) information, in a process of the terminal performing a radio resource control (RRC) connection re-establishment or a RRC connection establishment, the RLF information including at least one of: a tracking area code (TAC), a tracking area identifier (TAI) and a system identifier of a terminal access cell, wherein the RLF information is related to a time of RRC connection establishment or RRC connection re-establishment; reporting the RLF information to a network side device.

Provided are a method for supporting service continuity when a disaster situation ends, and a device supporting same. A user equipment (UE) receives, from a disaster roaming PLMN, a configuration update command message including information indicating that a disaster condition of a home PLMN (HPLMN) has ended. The UE waits until a service that is being received from the disaster roaming PLMN ends, and performs, after the service that is being received from the disaster roaming PLMN ends, a procedure of deregistration from the disaster roaming PLMN on the basis of information indicating that the disaster condition of the HPLMN has ended.

Provided are a method for adjusting timer T when disaster roaming occurs, and a device supporting same. When a disaster condition is applied to a home public land mobile network (HPLMN), a user equipment (UE) performs registration with a disaster roaming PLMN. When the registration with the disaster roaming PLMN is performed, a timer for periodically searching for the HPLMN does not operate, and the HPLMN is not searched while the timer does not operate. In addition, the UE re-operates the timer on the basis of the disaster condition no longer being applied to the HPLMN or the UE leaving a disaster area.

A method of operating a terminal in a wireless communication system includes receiving, from a base station, system information including information on a first discontinuous reception (DRX) cycle; transmitting, to an access and mobility management function (AMF), a request message including information on a second DRX cycle based on the first DRX cycle; receiving, from the AMF, a response message about the request message, wherein the response message includes information determined based on whether the AMF assigns the second DRX cycle; and determining a DRX cycle of the terminal based on the response message.

A method of operating a terminal in a wireless communication system includes receiving, from a base station, system information including information on a first discontinuous reception (DRX) cycle; transmitting, to an access and mobility management function (AMF), a request message including information on a second DRX cycle based on the first DRX cycle; receiving, from the AMF, a response message about the request message, wherein the response message includes information determined based on whether the AMF assigns the second DRX cycle; and determining a DRX cycle of the terminal based on the response message.

An AMF of a communications system responds to receipt of a network attach request message of a UE requesting attachment to a network of the communication system, by sending a charging data request message toward a CHF containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications associated with UE while attached to the network. The AMF receives a response message of the CHF containing a reference for the charging data resource associated with the UE while attached to the network. The AMF responds to receiving a PDU session establishment request message of the UE, by sending a PDU session establishment request message containing the reference for the charging data resource toward a SMF. Related SMF and CHF of the communications system are disclosed.