An Improved Broadcast Retransmission Protocol

A recent paper by Calo and Easton proposes a broadcast protocol for identical file transfers to
M
different sites wherein a large block of transmitted data is divided into
N
frames of
B
bits each, and in a second transmission cycle all frames not acknowledged by all sites are retransmitted. This paper shows several versions of a different technique which can result in better efficiency. In the technique, additional frames sent are not exact replicas of initially unacknowledged frames, but are chosen to provide additional information to all sites having one or more nondecodable frames. New frames are sent to provide additional information until all sites acknowledge the entire block.