Target location based sink positioning in wireless sensor networks

One of the main challenges in wireless sensor networks is to prolong the network lifetime by efficiently handling the limited battery life of the nodes. This problem becomes harder in applications where the nodes are randomly dropped in the field. In this paper we deal with the problem of the sink placement and of the network longevity, assuming a number of points in the field with known positions which must be covered by the sensors. Unlike other approaches, we consider the more realistic scenario where the coordinates of the sensors are not assumed to be known in advance and, thus, they cannot be used for the computation of the positions of the sinks. We present two solutions for the above problem; one based on the distance between the points and the second on the probability that a sensor may cover many points. We evaluate our approaches and compare them to algorithms that use the knowledge of the positions of the sensors in order to compute likely sink locations. It is shown that both proposed approaches present similar or better performance concerning network lifetime, while at the same time they significantly decrease the algorithm complexity.