Methods, systems, and devices for wireless communications are described. In some systems, a first base station and a second base station may be neighbor base stations and the first base station may receive, from the second base station, information relating to a multicast-broadcast services (MBS) session context of an MBS session supported by the second base station. The first base station may use the received MBS session context information to control communication or connections between the first base station and one or more user equipment (UEs) that are served by the first base station. For example, the first base station may use the received MBS session context information for target cell selection in a handover procedure, an MBS-specific measurement configuration, interference avoidance, or system information block (SIB) construction, among various other use cases.

A technique comprising: receiving, at a session management function, information by which is identifiable a plurality of multicast service areas for a multicast session managed by the session management function; and directing towards a radio access network node an indication of the plurality of multicast service areas; wherein the plurality of multicast service areas is a subset of the set of multicast service areas for the multicast session.

A method for implementing handover of a multicast broadcast service includes: receiving a handover complete indication transmitted by a target base station, the handover complete indication being used for indicating that a user equipment has been handed over to the target base station; and triggering establishment of a PDU session on a target base station side in response to a determination that the target base station does not support the MBS, S-NSSAI of the PDU session being the same as S-NSSAI of the activated MBS session, and a DNN of the PDU session being the same as a DNN of the activated MBS session, so that a quality of service flow corresponding to the activated MBS session is established in the PDU session, and there being one or more quality of service flows.

A user equipment includes a receiver configured to receive a data packet belonging to an MBS service via a PTM radio bearer, and a controller. The receiver receives, from a base station, configuration information for configuring association between the PTM radio bearer and a PTP data path for receiving the data packet belonging to the MBS service. The controller associates the PTP data path with the PTM radio bearer based on the configuration information.

A system and method for managing Multimedia Broadcast Multicast Service (MBMS) continuity. The system and method include transmitting, by a wireless communication device through a first distributed unit (DU) of a wireless communication node to a central unit (CU) of the wireless communication node, a first message. The first DU corresponds to a first subset of a plurality of MBMS services of the CU. The first message indicates a second subset of the plurality of MBMS services that corresponds to a second DU of the wireless communication node. The system and method include receiving, by the wireless communication device from the CU in response to transmitting the first message, a second message including MBMS scheduling information. The system and method include performing, by the wireless communication device, a handover procedure from the first DU to the second DU.

A method of processing state information relating to user equipment in a communications system comprising a radio access network, the method comprising: maintaining current state information relating to the user equipment; and on the basis of a change of connection of the user equipment from a first cell to a second cell: transmitting a current value associated with a given state information part to the target radio access node in response to detecting at least one of one or more predetermined triggers that indicate that the target radio access node may not have received the current value from the source radio access node; or relying on the target radio access node having received the current value from the source radio access node if said at least one of said one or more predetermined triggers is not detected.

Methods, apparatus, and systems for enabling effective reuse of a multicast or shared tunnel for a multicast and broadcast service are described. In one example aspect, a wireless communication method includes receiving, by a network node in a core network, information from a first access node requesting a multicast tunnel associated with a multicast and broadcast service, and transmitting, by the network node to the first access node, information about a shared tunnel associated with the multicast and broadcast service that has been established for a second access node.

Methods, apparatus, and systems for providing multicast handover are disclosed. In one example aspect, the method includes receiving, by a first radio access node, a multicast flow comprising data packets of a multicast service, determining, by the first radio access node, whether to initiate a handover procedure for a user device from the first radio access node to a second radio access node, replacing, upon determination to initiate the handover procedure, by the first radio access node, a first portion of the data packets with a flow identifier of a unicast flow, and forwarding, by the first radio access node, the data packets of the multicast service including the flow identifier of the unicast flow to the second radio access node.

A method for implementing multicast broadcast service handover includes: acquiring a PDU session associated with an MBS session, S-NSSAI of the PDU session being the same as S-NSSAI of the MBS session, a DNN of the PDU session being the same as a DNN of the MBS session; acquiring an MBS session identity of the MBS session; acquiring policy rule information corresponding to the activated MBS session from a PCF according to the MBS session identity, one or more pieces of policy rule information being provided; and establishing a quality of service flow corresponding to the activated MBS session on the PDU session according to the policy rule information corresponding to the activated MBS session, one or more quality of service flows being provided.

A method of operating a mobile communications network including a plurality of base stations and a base station for a mobile communications network, wherein the base station includes a plurality of transmitters, a plurality of receivers and a processor, is disclosed. Each transmitter is configured to transmit radio signals to a plurality of mobile terminals. Each receiver is configured to receive radio signals from a plurality of mobile terminals. The processor is configured to serve a mobile terminal via the transmitter over multicast/broadcast across a radio link; receive information from the mobile terminal being served by the transmitter, in which the information derives from signal quality of a multicast/broadcast serving signal received at the mobile terminal from the transmitter; and provide to the mobile terminal first instructions based on a first comparison of the quality of the multicast/broadcast serving signal received at the mobile terminal. The comparison is based on a first threshold; in which the first instructions instruct the mobile terminal to switch to unicast; and in which the processor is further configured to vary the first threshold in dependence on a measure of loading of the network.