Improving aloha via backoff tuning in underwater sensor networks

Aloha is a simple while important MAC protocol in underwater sensor networks (UWSNs). In specific networking environments it can provide the best performance. Furthermore, it serves as a basis for other complicated protocols, such as most RTS/CTS protocols or multi-channel MAC protocols. In the literature, there are various improvements on the Aloha protocol, in which many aim to avoid frequent collisions and others add make use of additional acknowledgement mechanisms to more efficiently schedule the actions of each node. However, all of these methods introduce more complexity to the protocol design, either leading to more collisions or requiring unrealistic hardware support. In this paper, we propose a backoff tuning scheme for Aloha. Analysis and simulation suggest that our method can scale in various configurations and can achieve better throughput than the original Aloha method. In addition, we evaluate the fairness of our method in an UWSN.