On the delay statistics of an aggregate of SR-ARQ packets over Markov channels with finite round-trip delay

In this paper, we investigate the delay statistics of an aggregate of fully reliable selective-repeat ARQ packets. The sender transmits packets whose error process is characterized by means of a two-state discrete time Markov channel (DTMC). At the receiver, these packets are checked for errors and ACK/NACK messages are sent back to the sender accordingly. No errors are accounted for in the reverse channel. The feedback message is assumed to be known at the transmitter m channel slots (round-trip delay) after the packet transmission started. An appropriate Markov model has been previously developed in order to find the exact statistics of the delays experienced by ARQ packets. This work presents an extension of the analysis that computes the delay statistics of an aggregate of ARQ packets. This is achieved without increasing the model complexity and allows useful considerations from the point-of-view of higher level protocols.