Transmitter Buffer Behavior of the Stop-arid-Wait ARQ Scheme Under Correlated Errors

摘要

This paper presents an analytical approach for analysing the queue length and the packet delay in the transmitter buffer of a system working under a Stop-and-Wait retransmission protocol. The buffer at the transmitter side is modelled as a discrete-time queue with an infinite storage capacity. The numbers of information packets entering the buffer during consecutive slots are assumed to be independent and identically distributed (i.i.d.) random variables. The packets are sent through an unreliable and non-stationary channel, which is modelled by a two-state Markov chain. An explicit formula is derived for the probability generating function (pgf) of the buffer contents. This pgf can then be used to derive several queue-length characteristics as well as the mean packet delay. By means of some numerical examples the effect of error correlation on the system performance is illustrated. Finally, the obtained analytical results are compared with appropriate simulations according to the described model.