An Energy-Efficient Protocol for Active/Sleep Schedule Synchronization in Wireless Sensor Networks

In wireless sensor networks, sensor nodes generally switch between active and sleep modes in medium access control (MAC) layer to reduce energy consumption. In previous synchronization protocols, each node begins to synchronize the active/sleep schedule with other nodes at the network setup phase and maintains the synchronization even if it has no packet to send. Therefore, the control overhead and energy consumption during synchronization can not be ignored under low traffic. In this paper, we propose a new active/sleep schedule synchronization protocol in the MAC layer. In our proposed method, each node synchronizes with its neighbors only when it has a packet to send. In addition, our protocol considers clock skew between nodes to maintain the synchronization for a longer period and reduce the number of control packet transmissions. We also study the advantages of our proposed method by introducing computer simulation results