Adaptive routing in underwater delay tolerant sensor networks

Underwater Sensor Network (UWSN) has attracted significant attention from both academia and industry. Different from terrestrial sensor nodes, underwater sensor nodes are usually mobile, much bigger, more energy-consuming, harder to recharge and suffer from more severe environmental conditions. Thus, an UWSN can be easily partitioned and no persistent routes from a source to a destination are available. Therefore, an UWSN can be viewed as a Delay/Disruption Tolerant Network (DTN). Moreover, an UWSN is always supposed to work for a long time to accomplish multiple tasks with various application requirements, such as delay and delivery ratio. Although many routing protocols have been proposed for DTNs, they are not suitable for UWSNs and cannot handle various application requirements. In this paper, we propose redundancy based adaptive routing (RBAR) for underwater DTNs. Through analysis and simulation, we demonstrate RBAR can achieve the best energy efficiency while satisfying different delay requirements of various packets by explicitly controlling the replication process.