Energy consumption analysis of underwater acoustic networks using fountain codes

Underwater sensor networks have a wide range of applications, but face great technical challenges due to the harsh nature of the acoustic channel. Moreover, most sensors are battery operated, making energy saving essential in network design. In this paper we analyze the energy consumption of an underwater network employing fountain codes, whose main idea is to transmit an undetermined amount of coded bits as to ensure a given target frame error rate (FER) at the receiver without the need for retransmissions. In addition we optimize the carrier frequency, signal-to-noise ratio (SNR) and the code rate for such target FER. Then, we analyze the amount of extra redundant frames needed by the fountain code as a function of the transmission distance. Our main contribution is to show that the use of fountain codes can decrease up to 30% the energy consumption, especially in long-range scenarios.