Energy Efficient Routing for Multi-hop Underwater Acoustic Networks

The goal of this paper is to establish the optimal routing path that minimizes the total energy consumption for a given target signal-to-noise ratio (SNR) for a 2-dimensional multi-hop underwater acoustic network. The energy efficient routing paths for both variable transmission power (VTP) and fixed transmission power (FTP) schemes were investigated. An empirical closed-form expression of the optimal frequency-distance relationship was derived as an effective way to simplify the calculation. It was shown that the total energy consumption of the network is minimized only if all the hop distances are equal for a linear multi-hop network for both VTP and FTP sceneries. In the case of equispaced relays, the analytical results on the optimal number of hops that minimizes the total energy consumption and the optimal total energy consumption of the network were also provided. The results may provide theoretic foundation for the establishment of nearshore resource monitoring system.