Resequencing delay and buffer occupancy in selective repeat ARQwith multiple receivers

The authors consider a selective repeat (SR) automatic-repeat-request (ARQ) protocol with one source and multiple receivers. Each receiver acknowledges all packets and handles its resequencing buffer based only on the packets that it receives error-free. An analysis of the resequencing delay and buffer occupancy at a receiver is presented. The authors construct a model that makes it possible to derive steady-state results, taking into consideration such system parameters as number of receivers, propagation delay, packet error probabilities, and acknowledgments. The authors focus on two measures of occupancy. The first measure corresponds to the number of packets waiting to be resequenced whereas the second measure includes, in addition, the buffer space reserved for packets that cause resequencing delays. The main results are the distribution of the resequencing delay and the distribution of the number of packets occupying the receiver's buffer