Date Added: Nov 2011
The relatively low spreading losses in underwater acoustic channels allows increased interference from distant interferers, which reduces the effectiveness of collision-avoidance MAC protocols. These collisions in turn reduce spatial reuse and network good-put, and increase power consumption. A competing channel effect, however, is the frequency-dependent absorption. The absorption can strongly suppress distant interferers, improving the effectiveness of collision-avoidance protocols. A third channel effect is frequency-dependent ambient noise, which reduces effectiveness for links consisting of widely separated nodes. RTS/CTS effectiveness generally decreases with decreasing acoustic frequency.