Performance comparison of TDMA variants for underwater acoustic sensor networks

In a network with long and random propagation delay, where sensor nodes communicate to a single receiver, there can be two variants of time division multiple access (TDMA), viz., receiver synchronized TDMA and transmitter synchronized TDMA. In receiver synchronized TDMA (RS-TDMA), the transmitter transmits according to the receiver's time slot and in transmitter synchronized TDMA (TS-TDMA), the transmitter transmits according to the transmitter's time slot. In this paper, we study RS-TDMA and TS-TDMA in the presence of distance dependent propagation delay deviation, which is one of the most important parameters for underwater wireless ad hoc networks. First we analyze RS-TDMA and TS-TDMA using discrete time Markov chain in the presence of distance dependent propagation delay deviation. Further we find the optimum parameters to get the maximum frame utilization and compare RS-TDMA and TS-TDMA with respect to arrival rate, transmission range, distance dependent propagation delay variability constant and slot size. In addition to the frame utilization we also parameterize the delay and blocking probability. Our numerical results are verified by discrete event based simulation results.