Modeling and Analysis of Hybrid ARQ Scheme for Incremental Cooperative Communication in Underwater Acoustic Sensor Networks

Abstract

Underwater acoustic sensor network (UASN) is a vast network, in which the neighborhood of a transmitting node consists of many operating sensor nodes. By considering this as an advantage, we propose a hybrid automatic repeat request scheme for incremental cooperative communication (HARQ-INCC) in UASNs. The proposed scheme utilizes neighborhood sensor nodes during the instance of packet retransmission. It combines HARQ scheme with incremental cooperative communication; to enhance reliability and to optimize the energy efficiency. In this article, we present an analytical model to calculate the energy efficiency in UASNs for deep and shallow water scenarios, by examining the influence of acoustic fading, ambient noises and underwater channel characteristics. The analytical results show that HARQ-INCC outperforms the existing techniques for considerable distances between the source and destination nodes. We further propose an optimization algorithm to maximize the energy efficiency, by adjusting the modulation level and packet size as a function of the distance between source and destination nodes. The proposed optimization algorithm significantly enhances the energy efficiency of HARQ-INCC scheme. Finally, we analyze the energy efficiency of UASNs with respect to the variation in environmental parameters like waves and shipping noises. We validate the analytical results using ns-3 simulations.