Method and apparatus for multicast/broadcast service

A method performed by a multicast/broadcast session management function (MB-SMF) in a first network, comprising:

• receiving an MBS session create request from a Network Exposure Function (NEF) or a Multicast/Broadcast Service Function (MBSF) in the first network or an application function (AF), wherein the MBS session create request comprises a multicast/broadcast service (MBS) session identifier (ID) and an associated session ID, wherein the associated session ID is associated with two or more broadcast MBS sessions of different MBS session IDs delivering a same content over two or more networks;
• and
• sending an MBS broadcast context create request to an access and mobility management function (AMF) in the first network, wherein the MBS broadcast context create request comprises the MBS session ID and the associated session ID,
• wherein at least one user plane is expected to be established for the two or more MBS sessions of the two or more networks.

A radio access network node, comprising:

• a processor;
• and
• a memory coupled to the processor, said memory containing instructions executable by said processor, whereby said radio access network node is operative to:
• receive a first request from a core network node in a first network, wherein the first request comprises a first multicast/broadcast service (MBS) session identifier (ID) for a first broadcast MBS session and an associated session ID, wherein the associated session ID is associated with two or more broadcast MBS sessions with different MBS session IDs delivering a same MBS content over two or more networks;
• and
• in accordance with a determination that a predefined number of user planes user plane connection delivering the MBS content associated to a second broadcast MBS session has been established with a network for multicast transport, skip joining a multicast group for receiving the MBS content from a Multicast/Broadcast User Plane Function (MB-UPF) in the first network which is originated from an application node;
• and/or
• for unicast transport, skipping allocation of downlink tunnel information for the first broadcast MBS session;
• wherein the first broadcast MBS session and the second broadcast MBS session are comprised in the two or more broadcast MBS sessions.

A multicast/broadcast session management function (MB-SMF) in a first network, comprising:

• a processor;
• and
• a memory coupled to the processor, said memory containing instructions executable by said processor, whereby said MB-SMF is operative to:
• receive an MBS session create request from a Network Exposure Function (NEF) or a Multicast/Broadcast Service Function (MBSF) in the first network or an application function (AF), wherein the MBS session create request comprises a multicast/broadcast service (MBS) session identifier (ID) and an associated session ID, wherein the associated session ID is associated with two or more broadcast MBS sessions with different MBS session IDs delivering a same content over two or more networks;
• and
• send an MBS broadcast context create request to an access and mobility management function (AMF) in the first network, wherein the MBS broadcast context create request comprises the MBS session ID and the associated session ID,
• wherein at least one user plane is expected to be established for the two or more MBS sessions of the two or more networks.