A critical analysis of Contiki's network stack for integrating new MAC protocols

Recent Wireless Sensor Network (WSN) MAC protocols focus on both very low idle trafic duty-cycle and high throughput when bursts of trafic occur. It is highly desirable to be able to integrate them into a common and open platform, not only for easing their performance comparison, but also for their effective interaction with existing higher-layer protocols. As part of our work on WSN, we have implemented a new Media Access Control (MAC) protocol into the Contiki OS. When doing so, we stumbled into various limitations and quirks, relative to this system—and especially its network stack. The present report summarizes the critical issues we have faced, and gives some ideas to fix them or work around them. Considering the widespread use of Contiki and its netstack, we believe that knowing those issues will be helpful for other researchers and developers.