The invention relates to a method for efficiently setting up a bidirectional multicast service in a mobile communication system. The bidirectional service is provided to a user equipment located in a radio cell controlled by a control entity. For the downlink data of the bidirectional service a downlink multicast service framework is utilized. In case the control entity decides for a point-to-point radio link to the UE, the system resources of the downlink framework are configured so as to re-use the configured system resources of the bidirectional service. This includes radio resources in the radio access network and may include tunnels in the core network. The invention further relates to a network entity in the CN or in the RAN for configuring system resources and for forwarding the multicast service data to the UE. The invention also relates to a mobile terminal for receiving the bidirectional multicast service.