The Research On The Techniques About Self-Deployed Underwater Acoustic Networks

Underwater acoustic networks can be rapidly deployed and flexibly reconfigured, which will play a more and more important role in many military and economy applications such as military surveillance, pollution monitoring, disaster prevention, assisted navigation, etc. In this paper, several key technologies about the network protocol stack are discussed and the performances of several modified versions of the stop and wait (S&W) ARQ protocol are compared.Firstly, the applicability of three existent topologies in underwater acoustic networks is discussed. Then the characteristics of the self-configure topology are analyzed and its network system model is given.Secondly, the architecture of the underwater acoustic networks is presented. The main functions in every layer of the protocol stack and several key technologies such as multiple access, error control, routing are discussed. And then a cross-layer approach to the integration of all communication functionalities is suggested.Acoustic modems typically operate in half-duplex, which limits the choice of a data link control protocol to the stop and wait type. Since the efficiency of the stop and wait ARQ is low, the throughput and energy consumptions of several modified versions are analyzed through simulations in capture 4. The simulation results show that the version that transmitter sends a group of M packets and waits for the acknowledgment is a good method.