Rainbow: Reliable Data Collecting MAC Protocol for Wireless Sensor Networks

We propose Rainbow, a MAC protocol designed to meet the reliability needs for data collecting wireless sensor networks (WSNs) in scenarios with radio frequency (RF) interference. In Rainbow, local time division multiple access (TDMA) and frequency hopping spread spectrum (FHSS) are combined to control channel access. The FHSS scheme is carefully designed to evade RF interference can be evaded. Correspondingly, a lightweight distributed time-frequency channel allocation algorithm Punch is proposed, which guarantees collision free communication. The protocol was evaluated in an actual implementation including 25 sensor nodes, which were deployed in environment with Wi-Fi devices. To the best of our knowledge, this is the first multichannel WSNs MAC protocol designed to achieve reliable data collecting in RF interference. The evaluation results showed that Rainbow was capable of achieving an end-to-end delivery probability greater than 99% with radio duty cycle less than 1%.