Using Cable-Based Mobile Sensors to Assist Environment Surveillance

In wireless sensor networks, mobile sensors are often employed for enhancing the sensing coverage and detection accuracy. Current approaches assume mobile sensors with the capability of arbitrary movement. The usage of such sensors with unlimited mobility, however, requires complicated sensor manufactures and high intelligence of movement which are practically unrealistic in many practical applications. We investigate the usage of cable-based mobile sensors which move along pre-deployed cables to accomplish sensing tasks at different positions. A target area is said to be reachable, if for any point in this area, at least one mobile sensor can move along the cable and achieve coverage to the point within a specified delay bound. We propose to achieve k reachability for the sensing field with minimum mobile sensors along the cable. Further, during special events, mobile sensors need to move and help surveillance. We need adjust the positions of the rest of mobile sensors accordingly to balance the reachability within the area. We prove the NP-hardness of the targeted problems and give heuristic approaches. Through comprehensive simulations, we evaluate the performance of this design and show its effectiveness.