Chrysso — A multi-channel approach to mitigate external interference

When a wireless sensor network is deployed indoors, sensor nodes often need to compete for channel usage with other, more powerful devices such as 802.11 access points. To mitigate the effects of such external interference we propose Chrysso, a protocol extension specifically designed for data collection applications that leverages the channel diversity of sensor node radios. In the face of external interference Chrysso switches only the directly affected set of nodes onto a new channel. In this paper, we present the design of Chrysso as well as its implementation in Contiki. Evaluation of Chrysso on two different testbeds, and its comparison with a state-of-the-art channel hopping protocol stack show that Chrysso is effective in maintaining a stable data flow at the sink, even under extreme interference.