Increasing the Lifetime of Underwater Acoustic Sensor Networks: Difference Convex Approach

The aim of this article is to develop and implement an optimal method for relay node placement (RNP) to increase lifetime of underwater acoustic sensor networks. Employing a relay node to extend the lifetime of critical node is an important problem in network lifetime maximization, whereas energy consumption of relay node is also a limiting factor. Consequently, maximizing the lifetime of critical node and minimizing consumption of relay node are the two main conflicting objectives that are met by applying the multiobjective optimization. To transform the above objectives into a single objective, weighted sum method is applied, which uses weights. Moreover, the RNP problem investigated in this article is a nonconvex problem, which difference convex algorithm (DCA), is developed in order to compute the optimal solution. Application of DCA offers the advantage of finding a global optimal solution. Simulation results backed by theoretical analysis confirm that the proposed approach is superior to the relay node adjustment method in terms of extending the network lifetime and efficiency, whereas their computational complexity is the same.