TLPC: A two-level power control MAC protocol for collision avoidance in underwater acoustic networks

Due to the nature of water, sound wave is used for underwater transmission instead of radio wave. Long propagation time and a variant attenuation model are two major concerns in MAC protocol design for underwater transmission. Although IEEE 802.11 DCF is the most famous MAC protocol, it does not work well in underwater environments. Therefore, according to the acoustic attenuation model, Control/DATA Collision (CDC) problem and Underwater Large Interference Range Collision (ULIRC) problem are conducted for underwater acoustic networks. This paper proposes a Two Level Power Control (TLPC) MAC protocol to prevent CDC and ULIRC problems. Taking interference into consideration, TLPC adapts the transmission power to resist interference and avoid collision in order to enhance network throughput. TLPC can not only prevent CDC and ULIRC problems but also can reduce the energy consumption of stations. Simulation results show that TLPC outperforms against other protocols in number of collisions and network throughput.