1 Performance of a Propagation Delay Tolerant ALOHA Protocol for Underwater Wireless Networks

We analyze a propagation delay tolerant ALOHA (PDT-ALOHA) protocol proposed recently for underwater networks [16]. In this scheme, guard-bands are introduced at each slot to reduce collisions between senders with different distances to the receiver. We prove some interesting properties concerning the performance of this protocol and show how it varies with key application and protocol parameters such as maximum propagation delay, traffic load, and the guard-band. Although it turns out that exact expressions for the maximum throughput of PDT-ALOHA can be quite complicated, we propose a useful simple expression which is shown numerically to be a very good approximation. I