Contiki-AMAC — The enhanced adaptive radio duty cycling protocol: Proposal and analysis

Energy-efficient operation is one of the prominent challenges for successful deployment of Wireless Sensor Networks (WSNs) along with maintaining certain quality of service (QoS) requirements. In this paper, we tackle the energy-efficient operation of WSN nodes implementation based on the Contiki real-time operating system (RTOS). We review the effect of applying spatial configuration for the radio duty-cycle (RDC) frequencies of WSN nodes running ContikiMAC. We propose an approach for enhancing the ContikiMAC duty cycling protocol, using adaptive radio duty cycling. Such approach would enhance multiple performance metrics of WSN's such as lifetime and sensory packets delivery ratio. Our proposal is based on two temporal duty cycles update mechanisms namely: a distributed mechanism in which a WSN sink node collects network-wide statistics and broadcasts a threshold value to sensory nodes for duty cycles adjustment, and an autonomous mechanism in which each node individually updates its duty-cycle based on local measured statistics. Such proposed framework should help achieving optimal balance between network lifetime and QoS requirements. Our simulation results for Contiki-AMAC show significant gains in network lifetime while maintaining network sensory packets delivery ratio at the same level, compared to static schemes of ContikiMAC.