Approximation Algorithms for Road Coverage Using Wireless Sensor Networks for Moving Objects Monitoring

Wireless sensor networks have drawn considerable attention among researchers for providing a low-cost framework for Intelligent Transport Systems. Coverage problem in wireless sensor networks measures quality a region or parts of it is sensed by the sensors. Definition of coverage metric depends on the applications for which sensors are deployed. In this paper, we introduce a new quality control metric/measure called road coverage to partially cover road networks. It can be used for measuring the efficiency of a sensor network, which is deployed for tracking moving/mobile objects in a road network. First, we propose different definitions of road coverage metrics. It is shown that the problem of deploying minimum number of sensors to achieve road coverage is NP-hard. It motivates to design centralized approximate solution. For axis-parallel road segments constant factor approximation algorithms are proposed for finding proper sensors positions. Experimental performance analyses of our algorithms are carried out through extensive simulations.