r 2 preferably the mbms list information indicates ues 2 that have joined a specific mbms which was not in progress at the time the ues moved in step 202 the serving rnc r 1 10 transmits an mbms attach request message including the ue list information for the specific mbms to the drift rnc r 2 10 the mbms attach request message may include information identifying the cell to which the ue 2 has moved and the specific mbms as well as the ue list information identifying which of the ues 2 having joined the specific mbms have moved to the cell managed by the drift rnc r 2 10 preferably the mbms attach request message is transmitted upon receiving a u201c session start u201d command from the core network 4 for a specific mbms that was not in progress when a ue 2 moved to a cell managed by the drift rnc r 2 upon receiving the mbms attach request message the drift rnc r 1 10 confirms the ue list information and performs an mbms attach process in step s 204 by adding the ues 2 indicated in the ue list information to a list of rrc connected ues managed by the drift rnc r 2 for.