A server-implemented method is disclosed. The method includes: receiving a request from an IP Multimedia Subsystem (IMS) network node of an IMS network; and in response to receiving the request, providing NAS registration state information associated with a user equipment (UE) to the IMS network node, the NAS registration state information indicating at least one of fourth-generation (4G) single radio voice call continuity (SRVCC) capability of the UE or fifth-generation (5G) SRVCC capability of the UE that is applicable when using an access network supported by a core network, wherein the server is configured to store separate instances of UE SRVCC capabilities, the separate instances including indications of at least one of 4G UE SRVCC capability or 5G UE SRVCC capability that is applicable when using the access network supported by the core network, and wherein the UE is registered with the IMS network using a session initiation protocol (SIP) via the access network.

A method for maintaining MBS session when UE performs intersystem change is provided. UE maintains a PDU session in 5G network. UE then joins an MBS session for receiving MBS service over the associated PDU session. Later on, UE performs intersystem change from 5G to 2/3/4G. The PDU session is then released or transferred to a PDN connection. From UE perspective, UE determines that the released or transferred PDU session is associated with the MBS session, and therefore locally leaves the MBS session. From NW perspective, NW determines that the released or transferred PDU session is associated with the MBS session, and therefore considers the UE is removed from the MBS session.

A method and corresponding apparatus are configured to transmit, during terminal attachment to an evolved packet system and in at least a portion of a diameter command, centralized service-related subscription information. The method and apparatus are also configured to transmit, in an initial message of a call continuity procedure, received centralized service-related subscription information. The method and apparatus are configured to operate according to the received centralized service-related subscription information in the initial message of the call continuity procedure.

Disclosed is a method and system for establishing a transmission channel in a fusion networking system. The method includes that an access side network element of a 3rd Generation Partnership Project (3GPP) system acquires Internet Protocol (IP) address information and/or port number information used when a Wireless Local Area Network (WLAN) system network element establishes an Xw interface, and initiates an establishment flow of a transmission channel of the Xw interface with the WLAN system network element according to the IP address information and/or the port number information.

A first user equipment (UE) device receives a configuration for a first timer from abase station that is serving the UE device. The first UE device also receives a recommended bitrate from the base station. The recommended bitrate is to be used for a Voice over Long-Term Evolution (VoLTE) call Or a Video over Long-Term Evolution (ViLTE) call between the first UE device and a second UE device. The first UE device activates the first timer in accordance with the configuration. The first UE device is prohibited from transmitting a bitrate query to the base station while the first timer is running. Upon receiving a recommended bitrate that is below a Guaranteed Bit Rate for the call between the first UE device and the second UE device, the first UE device stops the first timer and transmits a bitrate query to the base station.

A user equipment (UE) and an Internet Protocol (IP) Multimedia Subsystem (IMS) node may exchange fallback indicators in SIP signaling for purposes of controlling fallback procedures implemented by the UE. By sending fallback indicators to an IMS node in a SIP request, a UE is able to inform the IMS node of its capabilities in regards to particular fallback radio access technologies (RATs) that are supported by the UE. The IMS node may respond to the UE with a SIP response that includes information indicating which of the supported Fallback RATs the UE is authorized to use (if any), and which of the supported Fallback RATs the UE is not authorized to use (if any). In this way, the IMS node can control a fallback procedure at the UE by indicating which Fallback RATs are usable by the UE to reattempt communication sessions that cannot be established on an existing RAT.

A user equipment (UE) and associated method performs a voice call with a network, including exchanging voice packets, determines an uplink data transmission to be performed concurrently with the voice call and stores the uplink data transmission in a buffer. A base station and associated method performs a voice call with a UE, determines a downlink data transmission for the UE is to be performed concurrently with the voice call and stores the downlink data transmission in a buffer when the UE is a predetermined type. A UE and associated method associates with a first access point (AP), determines first performance characteristics of a connection with the first AP, determines second performance characteristics of a potential connection with a second AP, declares a radio link failure when the second performance characteristics exceed the first performance characteristics to trigger a handover procedure from the first AP to the second AP.

A service processing method and an apparatus are provided. The method may include receiving, by an access network device, a connection setup message sent by user equipment (UE), where the connection setup message includes first voice session indication information that indicates that the connection setup message is sent due to a Voice over Long Term Evolution (VoLTE) voice session. The method may also include preferentially allocating, by the access network device within a first time period that is after the access network device receives the connection setup message, an uplink transmission resource to the UE if receiving a resource scheduling request message sent by the UE.

The present invention relates to the field of mobile communications technologies, and in particular, to an information transmission method, an information modification method, and apparatuses, so as to solve a technical problem of voice transmission interruption in an SRVCC scenario in the prior art. In embodiments of the present invention, when a UE is in a connected state, a base station is notified of an SRVCC capability of the UE in real time, so that the base station can update the locally stored SRVCC capability of the UE in real time, and then determine, according to an actual situation, whether to initiate an SRVCC process, thereby ensuring a success rate of the SRVCC process and avoiding a possible phenomenon of call drop as far as possible.

Methods, systems, and devices for wireless communications are described. An access and mobility management function (AMF) associated with a first radio access network (RAN) may identify a user equipment (UE) connected to a source base station of the first RAN. The AMF may receive a handover message including a voice call continuity handover trigger message indicating a handover of the UE to a target base station associated with a second RAN. In some examples, the AMF may transmit a bypass handover message to a second network device based a on the received handover message. In some cases, the bypass handover message may include the voice call continuity handover trigger message. In some examples, the second network device is a mobility management entity (MME) associated with an Evolved Universal Terrestrial Radio Access Network (E-UTRAN).