Energy Efficient Routing for Multi-modal Underwater Wireless Sensor Networks

Multi-modal Underwater Wireless Sensor Networks (UWSN) have emerged as a promising technology for underwater sensing in Internet of Underwater Things (IoUT). Routing plays an important role in multi-modal UWSNs for the rapid and stable data transmissions. Due to the severe underwater environment, how to improve the energy efficiency is regarded as one of the most critical issues in the design of multi-modal routing protocols. In this paper, two improved energy efficiency routing algorithms are proposed for multimodal UWSNs. To ensure that nodes with more residual energy can transmit more information while protecting some nodes from premature death due to excessive energy consumption and paths with fewer hops can be used efficiently, we integrate the number of hops per transmission path as well as the residual energy of each relay node and its number of node-disjoint routes to the sink node as the constraints for calculating the size of information data that each node should forward to all of its relays. Therefore, our algorithms can reduce the overhead to deliver information data and improve the energy utilization of nodes. Simulation results show that our algorithms have a lower average transmission delay and a higher average energy efficiency.