Lei Tang, PRI-MAC: A Prediction-Wakeup MAC Protocol for Wireless Sensor Networks

This talk introduces PRI-MAC (Prediction-Wakeup MAC), a new energy-efficient MAC protocol based on asynchronous duty cycling. In PRI-MAC, nodes each wake up to receive at randomized, asynchronous times. PRI-MAC is designed to minimize sensor node energy consumption by enabling senders to predict receiver wake-up times; to enable accurate predictions, PRI-MAC introduces an on-demand prediction error correction mechanism that can effectively control the timing changes caused by challenges such as unpredictable hardware and OS delays and clock drift. PRI-MAC also introduces an efficient prediction-based retransmission mechanism to achieve high energy efficiency even when wireless collisions occur and packets must be retransmitted. We have conducted experiments on a testbed of MICAz motes to evaluate the performance of PRI-MAC compared to X-MAC, WiseMAC, and RI-MAC, three previous energy-efficient MAC protocols, under multiple concurrent multihop traffic flows and under hidden-terminal scenarios and scenarios in which nodes have wake-up schedule conflicts. In all experiments, PRI-MAC significantly outperforms these other protocols.