Next generation broadband satellite networks need to carry Internet traffic and multimedia traffic with burst charateristics. In practical IP packet service, MESs (Mobile Earth Stations) which have new messages need to temporally reserve several resource units in consecutive frames as well as one resource unit in a frame, and release them once a burst of data has been transmitted completely. In this thesis, we propose an enhanced MAC (Medium Access Control) scheme for multimedia services in satellite networks, Retransmission Announced Reservation Multiple Access (RARMA), in which resources are reserved according to the occasion demands by using spare reservation and later released using a distributed release scheme. We analyze the throughput and average packet delay of RARMA mathematically, and verify these results through numerical results and computer simulation. Characteristics of our proposed scheme are maximized throughput, minimized delay, variable message length and variable data rate. IP multimedia packet service in satellite networks can be supported effectively using our proposed MAC scheme.