Energy efficient and link reliable routing (E²LR) scheme for underwater sensor networks

Underwater Sensor Network (USN) is the wireless network infrastructure applicable in deep ocean to detect, collect, and transmit information to a remote data acquisition location on shore. Underwater routing protocols are used to provide route information in addition to ensuring efficient data and information collection and transmission. Some routing strategies for USNs are linked to high energy consumption, high end-to-end delay and shorter network lifetime. These issues are due to unnecessary packet flooding especially during route establishment, improper selection of next hop neighbor and frequent communication for route maintenance. Considering these challenges, this paper presents a localization free energy efficient and link reliable (E²LR) routing protocol that controls unnecessary flooding of hello packets to reduce energy consumption in the information distribution phase. Further, E²LR calculates the link quality using a composite metric for next hop selection which ultimately reduces end-to-end delay and regularly updates the energy status in order to achieve optimization during routing operations. Simulation results show that E²LR exhibit higher performance than both H²-DAB and R-ERP²R in terms of energy efficiency during information distribution phase and data forwarding phase. Moreover, E²LR also shows superior performance regarding end-to-end delay, network lifetime and packet delivery ratio than compared protocols.