A throughput bound for slotted CSMA with timer-based acknowledgments

An upper bound on throughput is derived for the combination of a slotted CSMA (carrier sense multiple access) protocol with a sliding-window transport protocol using timer-based acknowledgements. The bound is satisfied in the limit of increasing buffer size when only a single connection is active and queuing of acknowledgements can be ignored. The system is analyzed as a Markov chain, which would generally require the use of eigenanalysis. However, the special structure of the state diagram leads to a variant of the discrete-time renewal equation and allows the problem to be solved in a more direct fashion. Simulation results show good agreement with the theory, approaching the bound for large buffer sizes