The present disclosure provides a method for improving call performance in a wireless network. The method includes sending an invite request to a server to initiate a Voice over New Radio (VoNR) service, where the UE is connected with a first network entity, and where the invite request comprises a media feature tag. The method includes initiating an Evolved Packet System fallback (EPS FB) service timer based on the media feature tag and a quality of service (QoS) timer and establishing a call over a second network entity using a dedicated bearer when the EPS FB command is received from the server. The call is established over the second network entity using the dedicated bearer by sending a service request to the server and/or sending an update request to the server when the EPS FB timer is expired and the EPS FB command is not received from the server.

An electronic device of the disclosure may comprise: a communication circuit and at least one processor, wherein the at least one processor is configured to: control the communication circuit to transmit first capability information of the electronic device to a base station, identify, based on data throughput, whether an additional resource is needed, and based on identifying that the additional resource is needed, control the communication circuit to transmit an additional resource request message to the base station, wherein the first capability information comprises a request related to a basic resource, and the basic resource comprises at least one of a number of component carriers (CCs), a number of multiple-input multiple-output (MIMO) layers, or a bandwidth in an operating band.

A first access and mobility management function (AMF) in a network receives, from user equipment (UE), a registration request listing a first network slice and a second network slice. Upon determining that the first AMF supports the first, but not the second, network slice, the first AMF causes selection of (i) the first AMF as a session and mobility management (SM)-AMF to perform mobility management, and first session management signaling for the first network slice; and (ii) a second AMF as a session management only (SO)-AMF to perform only second session management signaling for the second network slice. The first AMF, acting as SM-AMF, performs the first session management signaling for a first data session on the first network slice, while the second AMF, acting as SO-AMF, performs only the second session management signaling for a second data session on the second network slice.

A first access and mobility management function (AMF) in a network receives, from user equipment (UE), a registration request listing a first network slice and a second network slice. Upon determining that the first AMF supports the first, but not the second, network slice, the first AMF causes selection of (i) the first AMF as a session and mobility management (SM)-AMF to perform mobility management, and first session management signaling for the first network slice; and (ii) a second AMF as a session management only (SO)-AMF to perform only second session management signaling for the second network slice. The first AMF, acting as SM-AMF, performs the first session management signaling for a first data session on the first network slice, while the second AMF, acting as SO-AMF, performs only the second session management signaling for a second data session on the second network slice.

An electronic device is provided. The electronic device includes a first communication circuit, a second communication circuit, a processor configured to be electrically connected with the first communication circuit and the second communication circuit, and a memory configured to be electrically connected with the processor. The memory includes instructions, when executed by the processor, cause the processor to obtain location information of the electronic device, transmit a first message for requesting to change a state of the electronic device to a network, receive a first response message to the transmitted first message from the network, transmit a second message for requesting a parameter for an operation cycle of the second communication circuit to the network, receive a second response message to the second message from the network, and change the operation cycle of the second communication circuit to a value corresponding to a current state of the electronic device.

This disclosure is related to a procedure of handling UE (100) behavior when the UE (100) is attached for emergency services. More specifically this disclosure defines the UE (100) behavior when the UE (100) is registered to a PLMN or two different PLMN via 3GPP access network and non-3GPP access network and UE (100) has is registered for emergency service over one of the 3GPP access network or non-3GPP access network.

This disclosure is related to a procedure of handling UE (100) behavior when the UE (100) is attached for emergency services. More specifically this disclosure defines the UE (100) behavior when the UE (100) is registered to a PLMN or two different PLMN via 3GPP access network and non-3GPP access network and UE (100) has is registered for emergency service over one of the 3GPP access network or non-3GPP access network.

According to an embodiment of the present invention, a method for selecting a public land mobile network (PLMN) by a user equipment (UE) in a wireless communication system comprises: in a manual network selection mode, displaying one or more first PLMN items corresponding to one or more first PLMNs on a display of the UE; when an input for a second PLMN item among the one or more PLMN items is received, controlling a communication module of the UE to attempt to register the UE on a second PLMN corresponding to the second PLMN item; when the registration on the second PLMN fails, providing access to restricted local operator service (RLOS), and displaying, on the display, one or more third PLMN items corresponding to one or more third PLMNs included in an RLOS PLMN list configured in a universal subscriber identity module (USIM) of the UE; and when an input for a fourth PLMN item among the one or more third PLMN items is received, controlling the communication module to initiate registration for access to the RLOS of a fourth PLMN corresponding to the fourth PLMN item, whereby it is possible to use not only excellent but also highly secure RLOS.

According to an embodiment of the present invention, a method for selecting a public land mobile network (PLMN) by a user equipment (UE) in a wireless communication system comprises: in a manual network selection mode, displaying one or more first PLMN items corresponding to one or more first PLMNs on a display of the UE; when an input for a second PLMN item among the one or more PLMN items is received, controlling a communication module of the UE to attempt to register the UE on a second PLMN corresponding to the second PLMN item; when the registration on the second PLMN fails, providing access to restricted local operator service (RLOS), and displaying, on the display, one or more third PLMN items corresponding to one or more third PLMNs included in an RLOS PLMN list configured in a universal subscriber identity module (USIM) of the UE; and when an input for a fourth PLMN item among the one or more third PLMN items is received, controlling the communication module to initiate registration for access to the RLOS of a fourth PLMN corresponding to the fourth PLMN item, whereby it is possible to use not only excellent but also highly secure RLOS.

A User Equipment (UE) including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception. The controller selects a PLMN via the wireless transceiver, and determines whether a predetermined ciphering algorithm is adopted for a Non-Access Stratum (NAS) security context. In response to selecting the PLMN and the predetermined ciphering algorithm being adopted for the NAS security context, the controller sends an initial NAS message in which Information Elements (IEs) are in cleartext only to the selected PLMN via the wireless transceiver.