The invention relates to a method for efficiently providing a bidirectional multicast service (e.g. IMS) to a user equipment (105), located in a radio cell, controlled by a control entity (104). For the downlink data of the bidirectional service a downlink multicast service (e.g. MBMS) is utilized. In case the control entity (e.g. RNC) decides for a point-to-point radio link to the UE, the bidirectional service is notified and system resources, established for the bidirectional service are utilized for providing the bidirectional service downlink data. This includes radio resources in the radio access network and may include connections in the core network. Optionally, the downlink multicast service may be de-activated for the specific mobile terminal, but the system resources already established may be maintained. 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.