RAWMAC: A Routing Aware Wave-based MAC Protocol for WSNs

In Wireless Sensor Networks (WSNs) for monitoring applications, energy saving and fast data collection are two challenging tasks. Asynchronous radio duty cycling protocols can achieve very low energy consumption in low traffic conditions and they are fault-tolerant to clock drifts. However, they may exhibit a delay degradation due to the decoupled wake-up periods of the nodes. In this paper, we present RAWMAC, a cross-layer approach where RPL, a tree-based routing protocol, orchestrates the asynchronous duty-cycled ContikiMAC MAC layer. The wake-up instants of the nodes are dynamically aligned, with respect to the RPL topology, to minimize the delay for data collection. We implement RAWMAC for the Contiki operating system and we analyze the impact of several key system parameters. Results show that RAWMAC outperforms ContikiMAC in terms of delay for data collection, while keeping the same performance in terms of throughput and energy consumption.