Date Added: Feb 2013
Normally, the communication in the earth surface is through electromagnetic or radio waves. But this is not possible in the underwater environments in an efficient way. In underwater environments radio does not work well due to its quick attenuation in water. Hence the acoustic signals are sent using the acoustic channels. If the communication is done with retransmission, it gives rise to the propagation delay and high error rate due to path loss and if the communication is done without retransmission the consumption of energy is high. In order to overcome these drawbacks Multipath Power control Transmission (MPT) is used. MPT consumes much less energy than the conventional one-path transmission scheme without retransmission.