This paper enhances the reliability of the data communication mechanism in GMPRS Logical Link Control(LLC) protocol,to address the issues of long delay and high bit error rates over GEO link.It proposes RBM-ARQ algorithm based on bitmap for reliable data communication.RBM-ARQ enhances the recovery of channel impairment by keeping the terminals updating the buffer status.Simulation results show when retransmission time and count are set properly,LLC layer throughput gets better and delay becomes smaller,and compared with GMPRS LLC layer acknowledged data transfer,RBM-ARQ algorithm achieves better performance and the better recovery of data.
