Towards optimal barrier coverage in wireless sensor and actor networks

Barrier coverage in sensor networks has attracted much attention in recent years. Existing results revealed that sensor mobility can remarkably improve the coverage performance of sensor networks. Considering the high manufacture cost of mobile sensors, in this paper we propose to tradeoff the barrier coverage performance and deployment budget by employing a wireless sensor and actor network (WSAN), wherein an actor is used to move static sensors around in order to enhance the barrier coverage performance. We first formulate the barrier coverage problem in WSAN and propose a new coverage metric to evaluate the barrier coverage performance. Then we design an efficient actor movement scheme, S-AMS, for the case where the number of monitoring points can be divided by the number of available sensors. By exploiting the actor´s mobility and clustering procedure, S-AMS is able to significantly improve barrier coverage. Based on the insight from S-AMS, we design G-AMS for the general case. We show that S-AMS achieves asymptotically optimal solution for the special case and G-AMS obtains close-to-optimal solution for the general case. Extensive simulations are conducted to demonstrate the performance of our proposed schemes.