Lifetime Maximization in Underwater Wireless Communication Networks

The rise in demand for underwater wireless communication networks (UWCN) has been driven by the emergence of new applications including unmanned underwater vehicles, deep-sea exploration, maritime and underwater archaeology research, and diver communications. For various applications, underwater network lifetime must be long, since unlike terrestrial sensor networks, it is a major job to change/recharge node batteries in underwater environments. In this paper, we introduce a solution where critical nodes in a UWCN are periodically recharged by small renewable energy sources. Further, a caching mechanism is introduced to relieve critical nodes of heavy workload when their residual energies run low. By leveraging these two techniques of energy replenishment and content-caching, the network lifetime extension challenge is formulated as an optimization problem. The results indicate that our proposed solution offers up to 45% longer UWCN lifetime compared to existing solutions.