Poster abstract: Multi-channel interference in wireless sensor networks

One solution for increasing the network throughput of a WSN is to use multiple orthogonal channels for transmission instead of a single channel. Multiple transmissions can take place on these orthogonal channels to increase the spectral efficiency. Typical WSN devices are equipped with a single transceiver with channel switching capabilities. These devices provide support for the use of multiple channels operating at different frequencies e.g., CC2420 radios used for MicaZ and Telos motes can use 16 different channels in the 2.4 GHz band. Use of multiple channels in WSN has been explored in previous research efforts and multi channel MAC and routing protocols has been proposed to improve the network throughput. Most of these protocols assume the presence of multiple orthogonal channels for parallel communications. One problem with use of multichannel in WSN is that channels are not truly orthogonal i.e., multiple simultaneous transmissions on adjacent channels do cause interference. Moreover interference caused by external networks e.g., WiFi operating in the same frequency band is also non trivial. It is thus imperative to consider these interference issues at the design stage of a multi channel protocol to avoid performance degradation during operation. We perform a detailed empirical study of these interference issues in multi channel WSN and present guidelines, based on this study, for design of efficient multi channel protocols for WSN.