A Data-Gathering, Dynamic Duty-Cycling MAC Protocol for Large-Scale Wireless Sensor Networks.

This paper presents a Data-gathering, Dynamic Duty-cycling (D3) protocol for wireless sensor networks. With a proposed duty-cycling MAC of high energy efficiency in D3, a routing scheme is naturally embedded to reduce protocol overhead. A packet can be forwarded in a pipelined fashion by staggering the sleep-wakeup schedules between two communicating nodes, which can significantly reduce end-to-end delay to meet real-time transmission requirements. To construct and maintain schedules, a grade and schedule establishment mechanism with a lightweight schedule error correction scheme is designed. In addition, based on the intrinsic characteristics of the network, an adaptive schedule maintenance scheme is proposed to dynamically adjust the node duty cycle to the network traffic load. The results based on the extensive OPNET simulations show that D3 can largely improve packet delivery ratio, energy efficiency and throughput, and reduce packet delivery latency.