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ROSS: receiver oriented sleep scheduling for underwater sensor networks

As the sleeping quality of a person would decline with repeated waking at night, similarly, for a sensor node in wireless sensor networks (WSN), waking up from dormancy frequently could cause energy waste by repeatedly switching on/off circuits and shorten the hardware lifetime. Existing sleeping schemes for WSN mainly focus on the maximization of sleep time as well as coordinating between sleep and communication, but just pay little attention to reduce the sleep frequency of nodes, especially for underwater sensor networks (UWSN). For the purpose of improving energy efficiency for nodes in UWSN, this paper proposes ROSS, a Receiver Oriented Sleep Scheduling strategy combining TDMA with duty-cycling. ROSS is designed on tree topology achieving no collisions and no channel reservation. Through allocating nodes' working time from root to leaves, ROSS ensures that each node can turn to sleep mode immediately after forwarding all the received data from its children. With asynchronous and periodic sleep scheduling determined by receivers, ROSS minimizes the sleeping-waking frequency and reduces end-to-end delay. Simulation results have confirmed its performance and efficiency.