Effective role-assignment for participatory sensing systems

Mobile phones are equipped with a rich set of sensors which are useful in deploying various sensing activities. We focus on participatory sensing in which every participant carrying smartphone senses its environment and shares it with server. Most of the applications require location information to perform sensing activity. But, GPS drains considerable amount of energy if used for localization. So, a set of devices are chosen as broadcasters which turn on GPS, and the neighbouring devices rely on them to calculate their position. We propose an efficient energy model to minimize the power consumption of such a system. The existing scheme for finding optimal set of broadcasters is based on greedy algorithm. This is time efficient only when the number of participants are small. We propose a sorting based algorithm. This provides better time complexity for moderate and large data sets which is the actual case in real scenarios. We validate our work with extensive experiments on both real and synthetic datasets. Results demonstrate that our proposed approach effectively minimizes energy and saves 12–25% of the time for medium and large data sets.