Solutions for providing a voice call for a user equipment (UE) include: monitoring, by a voice service control, voice call key performance indicators (KPIs) for the voice call of the UE, when the voice call comprises a voice over new radio (VoNR) call; determining, by the voice service control, that the voice call KPIs do not meet acceptable performance criteria; determining, by the voice service control, that an eNodeB (eNB) is co-located with a gNodeB (gNB) that is serving the UE; based on at least determining that the voice call KPIs do not meet acceptable performance criteria, and determining that an eNB is co-located with the serving gNB, instructing, by the voice service control, a radio access network (RAN) to begin an inter-radio access technology (IRAT) handover (HO) for the UE to the co-located eNB; and continuing the voice call as a voice over long term evolution (VoLTE) call.

This application provides a communications system for improving a telephone call completion rate in an SA network and user equipment. According to solutions of this application, in a scenario in which calling UE resides in an LTE network or a 5G SA network and called UE resides in the 5G SA network, when the calling UE fails to call the called UE through an IMS domain, the calling and called ends cooperatively execute a call saving policy: The calling UE performs a call retry, for example, when a VoNR call or an EPS fallback call fails, falls back to LTE to initiate a VoLTE call retry, or initiates a CSFB call retry on LTE when the VoLTE call fails. The called UE falls back to the LTE network or a CS domain, and cooperates with the calling UE to complete the call. In this way, a probability that the UE successfully initiates a call can be improved, a call requirement of a user can be met, and call experience of the user can be ensured.

Embodiments of the present invention include a method for enhanced indication of network support of SRVCC and/or Voice-over-IMS for an User Equipment UE in an Evolved Packet System EPS network, said method comprising at least one step based on taking into account support of SRVCC and/or Voice-over-IMS by Radio Access Network RAN nodes and/or by Radio Access Technologies RATs available for SRVCC for said UE in said EPS network.

Methods and apparatuses are provided for controlling a voice call at a user equipment (UE) in a wireless network. A method includes transmitting, to a network entity, a tracking area update (TAU) service request for a subsystem (IMS) initiation; receiving, from the network entity, a TAU service reject message; and in response to the TAU service reject message, stopping a circuit switch (CS) fall back call in at least one legacy radio technology (RAT).

An electronic device is provided. The electronic device includes a processor and a memory operatively connected to the processor. The memory stores instructions that, when executed, cause the processor to determine that IP multimedia subsystem (IMS) data to be transmitted and received between a first user equipment and a second user equipment can be processed by the same mobile edge computing (MEC) host based on location information received from the first user equipment and the second user equipment, instruct the MEC host to activate an IMS processing function, and transmit an address of the activated IMS processing function of the MEC host to the first user equipment and the second user equipment. Other embodiments are possible.

The disclosure generally relates to various methods to increase network coverage with respect to Voice-over-Internet Protocol (VoIP) sessions and/or other voice-based multimedia services. In particular, when establishing a voice session, two or more terminals may perform a codec negotiation to exchange information related to supported multimedia codecs and/or codec modes, jitter buffer management (JBM), and packet loss concealment (PLC) capabilities. Based on the exchanged information, a message may be sent to a base station to indicate the maximum packet loss rate (PLR) for each terminal. Additional techniques may ensure that the terminals use the most robust codecs or codec modes that are available when nearing the edge of coverage to help avoid unnecessary and/or excessive handovers to different radio access technologies.

Various embodiments of the present disclosure provide methods and apparatuses for service management. A method performed by a session management function includes receiving a first message including fallback information for a terminal device from an access and mobility management function. The fallback information includes a fallback type. The method further includes determining whether data buffering for the terminal device is required based on the fallback information. The method further includes, in response to a determination that the data buffering for the terminal device is required, sending a second message including a buffering indication to a user plane function, wherein the buffering indication indicates the user plane function to buffer the data for the terminal device.

The disclosure relates to a 5G or 6G communication system for supporting a higher data rate. A method performed by a user equipment (UE) includes receiving from a base station first configuration information including information on frequencies for early measurement reporting (EMR), receiving from the base station second configuration information including information on frequencies for cell reselection, transmitting to the base station a message including a measurement result of at least some of the frequencies for EMR and the frequencies for cell reselection, and performing EPS fallback to one frequency based on the measurement result. In case that the second configuration information comprises a field indicating fallback or the UE has switched to a connected mode to start an IP multimedia subsystem (IMS) voice service, the message comprises a measurement result of at least some of the frequencies for cell reselection.

A wireless communication network uses a wireless network slice. The wireless communication network transfers slice information for the wireless network slice to a user data system. The wireless communication network receives a request from the user data system for user data from the wireless network slice. The wireless communication network receives the user data from a wireless user device over the wireless network slice. The wireless communication network transfers the user data to the user data system in response to the request.

The disclosure relates to a 5G or 6G communication system for supporting higher data rates. The disclosure discloses a method and an apparatus capable of optimizing early EPS fallback. A method performed by a terminal in a wireless communication system includes receiving, from a base station of a first RAT, a message to command an inter-RAT HO, the message including information indicating that the inter-RAT HO is triggered by EPS fallback for IMS voice; performing the inter-RAT HO based on the message; based on a failure of the inter-RAT HO, identifying whether there is a suitable cell of a second RAT for selection; in case that there is no suitable cell of the second RAT, selecting an acceptable cell of the second RAT based on the IMS voice being for an emergency service; and logging a time until the terminal accesses the acceptable cell of the second RAT.