Triggering MBS inactive reception mode announcement

1 . An apparatus comprising:

one or more processors, and

memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform:

receiving a request, wherein the request requests a radio access network (RAN) node to broadcast an advertisement of a multicast session, wherein the advertisement indicates that the apparatus transmits data for the multicast session in a transmission mode for inactive reception, and wherein the data transmitted in the transmission mode for inactive reception is suitable to be received by a first terminal in an inactive state,

wherein the request comprises:

an identifier of the multicast session,

assistance information indicating whether or not applying the transmission mode for inactive reception for transmitting the data for the multicast session is preferred,

an indication of a service area of the multicast session;

determining one or more cells associated with the apparatus based on the service area received in the request;

determining, for each cell of the one or more cells, whether or not the RAN node transmits the data for the multicast session in the transmission mode for reception in inactive state or in a transmission mode for reception in connected state based on the following:

whether or not the RAN node receives the request to broadcast the advertisement;

a number of terminals wanting to receive the multicast session in the cell;

a radio resource control (RRC) state of terminals in the multicast session in the cell;

a load in the cell;

capabilities of terminals that have joined the multicast session in the cell to receive data for the multicast session while in inactive state; and

assistance information received as part of the request to broadcast;

determining the apparatus is configured to transmit the data for the multicast session in the transmission mode for inactive reception;

broadcasting the advertisement periodically in the one or more cells based on the receiving the request and the determining that the apparatus is configured to transmit the data for the multicast session in the transmission mode for inactive reception, wherein broadcasting the advertisement includes an indication of the determined transmission mode;

supervising, for each of the one or more cells, whether the RAN node receives an indication that the first terminal desires to receive the data for the multicast session,

wherein the indication that the first terminal desires to receive the data for the multicast session comprises:

an interest indication, and

a preamble transmitted while the first terminal is in the inactive state;

multicasting the data for the multicast session in the cell in the transmission mode for reception in inactive state if the cell receives the indication that the first terminal desires to receive the data for the multicast session;

supervising for each of the one or more cells whether at least one second terminal in connected state that joined the multicast session is in the cell;

multicasting the data for the multicast session in the cell if second terminal in connected state that joined the multicast session is in the cell;

inhibiting the multicasting the data for the multicast session in the cell if the cell does not receive the indication and none of the at least one second terminal in the connected state that joined the multicast session is in the cell; and

requesting the establishment of shared data delivery for the multicast session when starting to multicast the data for the multicast session.