A Sink-Triggered Data Gathering Protocol in Underwater Sensor Network

This paper proposes a medium access control(MAC) protocol that allows a centralized sink to trigger scattered sensors to transmit data according to the sink's arbitrary scheduled times, It doesn't require any synchronization procedure to acquire the propagation delay between the sink and sensors. The proposed protocol aims to adapt to the heterogeneous traffic demands of each sensor by allocating different numbers of timeslots. Results show that the proposed scheme outperforms a time division multiple access(TDMA) which is a typical MAC protocol for data gathering in terms of packet delay and channel utilization under conditions of uneven traffic demands among sensors.