Reliable multicast via satellites

Automatic repeat request (ARQ) is a well-known technique to provide error control. In reliable satellite multicasting, ARQ may reduce system throughput as the number of receivers increases since the satellite has to retransmit a packer until all receivers correctly receive it. This performance degradation might be alleviated substantially by conducting retransmissions through terrestrial paths from the sender to each receiver instead of through the multicast satellite link. However, this approach may not be possible when some receivers do not have terrestrial connections to the sender. Also, a large volume of feedback traffic from the receivers to the sender may cause a feedback implosion at the sender. In this paper, we propose a scalable framework to solve these problems. Our solution enables receivers to form groups to avoid unnecessary retransmissions as long as a correct packet call be found inside the group. Using analytical models, we demonstrate that the proposed solution can significantly improve system throughput