Flock detection based duty cycle scheduling in mobile wireless sensor networks

For mobile sensor networks, it is important for nodes to exchange data so that the data delivery probability can be increased. In order to communicate with each other, nodes need to detect each other through sending and receiving beacons. Due to the strict constraint of energy supply, a sensor node without being in sleep mode cannot work long enough to meet the applications´ lifetime requirements. Hence nodes need to work in low duty cycle to conserve energy. This working style makes it difficult for the nodes to discover each other and consequently will decrease the possibility for the data exchange among nodes. In order to increase the efficiency of energy usage, it is necessary for nodes to adjust their duty cycles according to the change of the number of the neighbouring nodes. In this paper a flock detection based duty cycle scheduling scheme is proposed for the mobile sensor network with non-periodic motion pattern. Based on the flock detection method through neighbour node number estimation presented in this paper, the duty cycle scheduling scheme is designed to increase the efficiency of the energy use of the sensor node. Experimental results show that the mechanism is able to significantly improve the performance of the system.