A MACA-based power control MAC protocol for Underwater Wireless Sensor Networks

In an energy-constrained underwater system environment, it is very important to find ways to improve the life expectancy of sensors. The basic power control scheme has been proposed in underwater MAC protocol design, of which the main idea is to use different power levels for RTS-CTS and DATA. Specifically, the maximum transmission power is used for RTS-CTS, and the minimum required transmission power is used for DATA. However, this mechanism would greatly degrade network throughput when used in MACA for Underwater Wireless Sensor Networks (UWSNs). In this paper, we propose a MACA-based power control MAC protocol (MACA-PC). Similar to the basic power control scheme, MACA-PC uses lower transmission power to send data packets. Differently, MACA-PC periodically adds a Notification Signal (NS) with the maximum transmission power during the transmission of data packets to inform other nodes to avoid collisions. Our simulations show that the MACA-PC can minimize the energy consumption and it rarely degrades the network throughput.