The Redeployment Issue in Underwater Sensor Networks

The mobility of underwater sensor nodes makes the network topology inconveniently controlled and slowly changed. Thus, in order to enable underwater sensor networks to work more effectively, it is necessary for us to periodically detect the coverage rate and redeploy nodes to non-coverage areas. In this paper, we take the lead in introducing the redeployment issue in underwater sensor networks. In our opinion, the key point of the redeployment issue is coverage. For this special coverage topic, we first propose a coverage rate definition scheme. Then along with the definitions, two redeployment algorithms are introduced, of which one is based on adding new nodes while the other one is by the means of moving redundant ones. By modeling the mobility behavior of underwater nodes with three-dimensional random walks, we employ simulation experiments to verify our ideas, the results of which show the importance of redeployment in the underwater environment.