The University of the District of Columbia Washington United States
In this thesis, we propose an experimental approach to enhance the performance of the underwater acoustic sensor networks and to decrease the network power consumption. Distributed Underwater Wireless Sensors Network UWSN, based on acoustic waves, is an area of active research in underwater communications. UWSN is widely used in applications, such as military surveillance, disaster monitoring and ocean observation. UWSN has many constraints mainly due to limited capacity, propagation loss, as well as power limitation since in underwater environment solar energy cannot be used to recharge batteries. In our approach, we estimate the number of operating receivers within the network based on the knowledge of the Bit-Error-Rate BER and the signal detection of the transmitted message, and, therefore, take advantage of the BER variation, which depends on the underwater acoustic channel environment. In our experimental observations, we considered two network models multi hop relay acoustic sensors network and parallel acoustic sensors network. In the second part of the research, we use the information theoretic aspects to analyze and study the impact of using mobilemoving sensor nodes, as opposed to fixed nodes in UWSN. The jump from fixed sensor nodes to moving sensor nodes enables many advantages in UWSN, but also introduces several complications. The two main significant advantages of using mobile sensor nodes over fixed nodes are a the reduction of sensor nodes needed, and b the ability to handle dynamic situation. Thus, the same work can be accomplished by fewer mobile nodes instead of a large number of fixed sensor nodes. Also, we developed software SAM Control written in MATLAB programming language to facilitate our experiments.