ARQ protocols for bi-directional data transmission

Automatic repeat request (ARQ) protocols are discussed so far to analyze the buffer size and the delay required for two peer processes. However, ARQ protocols in group communications are not discussed, where multiple senders send packets to multiple receivers. In the group communication protocols, acknowledgments of packets received are piggy-backed by packets. Hence, the forward and feedback channels are considered to be combined to one bi-directional channel. In addition, since each process has the buffer both for retransmitting and for resequencing packets sent and received, efficient buffer allocation schemes have to be adopted. In this paper, we analyze the throughput of the ARQ protocol for the group communications.