Adaptive duty-cycling based on group size for energy balance of sensor nodes in wireless sensor networks

Recently one of the most important issues in wireless sensor networks is to prolong the network lifetime. Research on scheduling the wireless interfaces of the nodes has been proposed, since the nodes consume most of their energy on wireless communication. Under the sleep/wakeup protocol, the wireless interface of each node follows a cycle of sleep/active modes without considering the network connectivity. It causes additional communication delays. Topology control schemes have been proposed to minimize these delays and extend the network lifetime. However, they do not enable all nodes to have a similar lifetime. It reduces network coverage and prevents seamless communication. We propose an Adaptive Duty-Cycling (ADC) approach. The ADC scheme ensures a similar lifetime of all nodes while minimizing a small additional communication delay by applying a different duty-cycle to each group. Simulation results show the proposed scheme extends the network lifetime at least 25% compared to conventional ones. It also keeps the communication delay constant throughout the network lifetime.