An Inter-networking Mechanism Using Stepwise Synchronization for Wireless Sensor Networks

To realize the ambient information society, multiple wireless networks deployed in the region or carried by users are required to cooperate with each other. Since duty cycles and operational frequencies are different among networks, we need a mechanism to allow networks to efficiently exchange messages. In this paper, we propose a novel inter-networking mechanism where two networks are synchronized with each other in a moderate manner, which we call stepwise synchronization. With our proposal, nodes near the border of networks adjust their operational frequencies in a stepwise fashion to bridge the gap between intrinsic operational frequencies. For this purpose, we adopt the pulse-coupled oscillator model as a fundamental theory of synchronization. Through simulation experiments, we show that the communication delay and the energy consumption of border nodes are reduced, which enables wireless sensor networks to communicate longer with each other.