Enhancement of the IEEE 802.15.4 MAC protocol for scalable data collection in dense sensor networks

We find that the IEEE 802.15.4 MAC protocol performs poorly for one-hop data collection in dense sensor networks, showing a steep deterioration in both throughput and energy consumption with increasing number of transmitters. We propose a channel feedback-based enhancement to the protocol that is significantly more scalable, showing a relatively flat, slow-changing total system throughput and energy consumption as the network size increases. A key feature of the enhancement is that the back-off windows are updated after successful transmissions instead of collisions. The window updates are based on an optimality criterion we derive from mathematical modeling of p-persistent CSMA.