Strategies on TDMA slot allocation in underwater acoustic networks

Due to the low speed of sound in water, underwater acoustic networks (UWANs) have large propagation delays as compared to terrestrial networks. In this paper, we propose the strategies on TDMA slot allocation in underwater acoustic networks that utilize diversity of node position and large propagation delays of the underwater channel to facilitate concurrent transmission and achieve the maximum possible throughput. First, we propose non-slotted TDMA strategy in underwater acoustic networks. Specifically, we specify the constraints that the strategies need to satisfy to avoid conflicts and model these constrains into a set of difference equations. Second, we use the Bellman-Ford algorithm to solve difference equations and get transmission schedule. Finally, we study the throughput of ring networks using the non-slotted TDMA strategy.