Rendezvous Enhancement in Arbitrary-Duty-Cycled Wireless Sensor Networks

Prolonging network lifetime is always a critical issue in wireless sensor networks (WSNs). To reduce energy consumption, utilizing duty cycling, i.e., sensor nodes switching to sleeping mode for most of the time, is a common strategy in WSNs. However, without properly scheduled, sensor nodes may not be able to stay awake simultaneously to communicate with each other. That is, nodes may not have a rendezvous to each other. To solve this problem, in this paper, we propose a new scheduling mechanism, Staggered Scheduling (SS). By adjusting each node´s instantaneous duty cycle in a staggered way, the SS scheme can i) ensure each pair of nodes a rendezvous in a limited time span, ii) produce more rendezvous when compared with existing mechanisms, and iii) allow each sensor node to choose its target duty cycle independently. Extensive simulation results verify the superiority and feasibility of the proposed SS scheme.