Some selective repeat ARQ schemes for point-to-multipoint communication

The authors consider some electric selective repeat automatic repeat request (ARQ) schemes suitable for point-to-multipoint communication over broadcast channels. In these schemes, multiple copies of each data block are sent contiguously instead of one single copy. A data block is considered successfully transmitted if it is positively acknowledged at least once by each receiver during all the transmission attempts. The mean delay time analysis is carried out assuming infinite receiver buffer size. In the case of geometrically distributed interarrival times, the analyzed results show excellent agreement with the simulated results. Based on numerical results, a considerable performance improvement can be achieved by sending each data block the optimum number of copies instead of just one single copy. The effect of finite receiver buffer size was taken into account by simulation. It was found that even with a small receiver buffer, the system performance degraded only slightly