Crankshaft: An Energy-Efficient MAC-Protocol for Dense Wireless Sensor Networks

This paper introduces Crankshaft, a MAC protocol specifically targeted at dense wireless sensor networks. Crankshaft employs node synchronisation and offset wake-up schedules to combat the main cause of inefficiency in dense networks: overhearing by neighbouring nodes. Further energy savings are gained by using efficient channel polling and contention resolution techniques. Simulations show that Crankshaft achieves high delivery ratios at low power consumption under the common convergecast traffic pattern in dense networks. This performance is achieved by trading broadcast bandwidth for energy efficiency. Finally, tests with a TinyOS implementation demonstrate the real-world feasibility of the protocol.