HYMAC: Hybrid TDMA/FDMA Medium Access Control Protocol for Wireless Sensor Networks

We describe HyMAC, a new hybrid MAC layer protocol for wireless sensor networks that is, to the best of our knowledge, the first effort to combine the strengths of both TDMA and FDMA schemes in these constrained networks. While allowing the network to operate in an energy-efficient collision-free manner, HyMAC takes advantage of the multiple frequencies provided in the radio component of recent sensor node hardware platforms such as MICAZ, TELOS and FireFly. We show how HyMAC outperforms protocols such as B-MAC, RT-Link and MMSN achieving high throughput and small bounded end- to-end delay suitable for newer types of sensor network applications such as real-time voice streaming.