A radio access network (11) facilitates transmission of a Multimedia Broadcast/Multicast Service to plural user equipment units served by a radio base station. A radio network controller node (26) includes in a first message (70) of a Common Transport Channel Setup procedure an indication that sharing of a common transport bearer (60) involved in a session of the Multimedia Broadcast/Multicast Service is allowed. A radio base station (28) makes a determination whether to share the common transport bearer (60) among user equipment units (30) situated in plural cells (C) served by the radio base station (28). If the determination is positive, the radio base station (28) includes in a second message (80) of the Common Transport Channel Setup procedure an identification of an already-established channel to be used as the shared common transport bearer. The radio network controller (26) then uses the already-established channel as the shared common transport bearer for transmitting Multimedia Broadcast/Multicast Service user data to user equipment units (30) situated in plural cells served by the radio base station.