Base station, network node, first core network node, second core network node, and a method performed by them

A distributed unit of a base station for providing Multicast and Broadcast Services (MBS), the distributed unit comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• transmitting, to a central unit of the base station, a message including first information identifying a user plane tunnel between the central unit and the distributed unit associated with an MBS session, wherein the message indicates that the user plane tunnel is a shared tunnel;
• and
• receive, via the shared tunnel, user plane protocol data unit for the MBS session for transmitting to a user equipment (UE), upon transmitting the message.

A distributed unit of a base station for providing Multicast and Broadcast Services (MBS), the distributed unit comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• receive, from a central unit of the base station, a request for setting up a user plane tunnel between the central unit and the distributed unit associated with an MBS session as a shared tunnel, the request including second information of the MBS session and first information identifying the user plane tunnel;
• and
• receive, via the shared tunnel, user plane protocol data unit for the MBS session for transmitting to a user equipment (UE), upon receiving the message.

A central unit of a base station for providing Multicast and Broadcast Services (MBS), the central unit comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• receive, from a distributed unit of the base station, a message including first information identifying a user plane tunnel between the central unit and the distributed unit associated with an MBS session, wherein the message indicates that the user plane tunnel is a shared tunnel;
• and
• transmit, via the shared tunnel, user plane protocol data unit for the MBS session to a user equipment (UE), upon receiving the message.

A central unit of a base station comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• transmit, to a distributed unit of the base station for providing Multicast and Broadcast Services (MBS), a request for setting up a user plane tunnel between the central unit and the distributed unit associated with an MBS session as a shared tunnel, the request including second information of the MBS session and first information identifying the tunnel;
• wherein the shared tunnel is configured to be used, by the distributed unit, for transmitting user plane protocol data unit for the MBS session.

A first core network node for managing at least one Multicast and Broadcast Services (MBS) session provided using a shared tunnel, the first core network node comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• transmit, to a second core network node for managing a user plane associated with the at least one MBS session, a session management message including information identifying one or more MBS session to be added at the second core network node, in a case where the shared tunnel has not been established yet.

A second core network node for managing a user plane associated with at least one Multicast and Broadcast Services (MBS) session provided using a shared tunnel, the second core network node comprising:

• at least one memory storing instructions;
• and
• at least one processor configured to process the instructions to:
• receive, from a first core network node for managing the at least one MBS session, a session management message including information identifying one or more MBS session to be added at the second core network node, in a case where the shared tunnel has not been established yet.