SCT-MAC: A scheduling duty cycle MAC protocol for cooperative wireless sensor network

Effective techniques for extending lifetime in multihop wireless sensor networks (WSNs) include duty cycling and more recently introduced cooperative transmission range extension. However a scalable MAC protocol has not been presented that combines both. In this study, we present a new scheduling cooperative MAC protocol (SCT-MAC) for the multi-hop wireless sensor network, which introduces distributed duty-cycle scheduling and enables nodes to wake up on demand in the data period. The protocol provides a wake-up rendezvous for cooperators to reach a CT agreement and reduces contention over adjacent flows, and the on-demand wake-up further reduces idle listening in the data period. We compare SCT-MAC with DW-MAC using NS-2 simulation, and show that SCT-MAC improves the network lifetime by approximately 100%.