Collision-free anycast transmission scheduling in UWSNs

Underwater Wireless Sensor Network (UWSNs) have been proposed to monitor underwater regions such as seas and oceans. A typical example of an UWSN consists of a set of underwater sensor nodes and a set of sink nodes that are deployed at the sea surface. Using acoustic transmission, the sensors send their collected data to at least one of the sinks in what is known as the anycast transmission problem. One of the major problems with underwater nodes is their limited power, which means that transmission collisions are very costly. In this paper, we propose a collision-free anycast transmission scheduling algorithm for UWSNs. The proposed algorithm is a location-based routing algorithm that schedules transmissions between sensor nodes and sink nodes in order to minimize the energy consumption and possible collisions. We perform a set of experiments using the NS2 Aqua-Sim simulator to show that the proposed algorithm can provide up to 26% in energy savings compared with a simple greedy algorithm.