One embodiment of the present specification relates to a method by which a relay UE performs communication, comprising the steps of: receiving, from an access and mobility management function (AMF), a UE configuration update command message including information for requesting registration of the relay UE; transmitting, to a remote UE, a message indicating suspension of a PC5 connection; receiving, from the remote UE, a message indicating that the PC5 connection has been completely suspended; transmitting, to the AMF, a UE configuration update complete message in response to the UE configuration update command message; performing a registration procedure with the AMF; and resuming the PC5 connection with the remote UE.

One embodiment of the present specification relates to a method by which a relay UE performs communication, comprising the steps of: receiving, from an access and mobility management function (AMF), a UE configuration update command message including information for requesting registration of the relay UE; transmitting, to a remote UE, a message indicating suspension of a PC5 connection; receiving, from the remote UE, a message indicating that the PC5 connection has been completely suspended; transmitting, to the AMF, a UE configuration update complete message in response to the UE configuration update command message; performing a registration procedure with the AMF; and resuming the PC5 connection with the remote UE.

The present disclosure relates to a 5th generation (5G) or pre-5G communication system for supporting a higher data transmission rate after a 4th generation (4G) communication system such as long-term evolution (LTE). According to various embodiments of the present disclosure, an operating method of a terminal in a wireless communication system provide a method including performing a registration procedure for a first public land mobile network (PLMN), receiving a downlink (DL) non-access-stratum (NAS) transport message including slice roaming information from an access and mobility management function (AMF) of the first PLMN, transmitting an uplink (UL) NAS transport message to the AMF, and performing a PLMN selection procedure using the slice roaming information.

Example devices, systems, and methods for emulating a PTT device at an incident location are provided. An example server receives a request for a remote push-to-talk (PTT) device to be emulated at a target location in a vicinity of an incident, selects local communication infrastructure that supports public safety services for local PTT devices located near the target location, and ransmits, to the local communication infrastructure, instructions for the local communication infrastructure to register an emulated PTT device as a proxy for the remote PTT device at the target location.

Example devices, systems, and methods for emulating a PTT device at an incident location are provided. An example server receives a request for a remote push-to-talk (PTT) device to be emulated at a target location in a vicinity of an incident, selects local communication infrastructure that supports public safety services for local PTT devices located near the target location, and ransmits, to the local communication infrastructure, instructions for the local communication infrastructure to register an emulated PTT device as a proxy for the remote PTT device at the target location.

Embodiments of this application provide example communication methods and apparatuses. One example method includes receiving, by a first network device, a first request message and uplink data from a terminal, where the first request message is for requesting to resume a suspended radio resource control (RRC) connection. The first network device can then send a second request message to a second network device based on the first request message and the uplink data, where the second network device is a network device previously serving the terminal, and the second request message includes information about the uplink data, where the second request message is for requesting the second network device to release a first data channel between the second network device and a core network device, or the second request message is for requesting the second network device to send a context of the terminal to the first network device.

The present application relates to supporting eDRX by a RedCap UE. In an example, a UE indicates to a network that the UE is operating as a RedCap UE and requests an eDRX configuration. In response, the network selects one or more values for the eDRX and sends such value(s) to the UE.

The present application relates to supporting eDRX by a RedCap UE. In an example, a UE indicates to a network that the UE is operating as a RedCap UE and requests an eDRX configuration. In response, the network selects one or more values for the eDRX and sends such value(s) to the UE.

Systems and methods are provided for public land mobile network (PLMN) selection for disaster roaming. A user equipment (UE) determines a disaster condition at a first PLMN, where the UE is a subscriber of the first PLMN. The UE determines an availability of a second PLMN for disaster roaming. The UE selects the second PLMN and attempts registration on the second PLMN for disaster roaming. In response to attempting the registration on the second PLMN for disaster roaming, the UE receives a registration reject message including a cause value corresponding to a registration failure for disaster roaming on the second PLMN due to the disaster condition on the first PLMN. The UE waits for a first period of time before again attempting to register for disaster roaming on the second PLMN for the first PLMN with the disaster condition.

Systems and methods are provided for public land mobile network (PLMN) selection for disaster roaming. A user equipment (UE) determines a disaster condition at a first PLMN, where the UE is a subscriber of the first PLMN. The UE determines an availability of a second PLMN for disaster roaming. The UE selects the second PLMN and attempts registration on the second PLMN for disaster roaming. In response to attempting the registration on the second PLMN for disaster roaming, the UE receives a registration reject message including a cause value corresponding to a registration failure for disaster roaming on the second PLMN due to the disaster condition on the first PLMN. The UE waits for a first period of time before again attempting to register for disaster roaming on the second PLMN for the first PLMN with the disaster condition.