SoNIC: classifying interference in 802.15. 4 sensor networks

Sensor networks that operate in the unlicensed 2.4 GHz fre-quency band suffer cross-technology radio interference from a variety of devices, e.g., Bluetooth headsets, laptops using WiFi, or microwave ovens. Such interference has been shown to significantly degrade network performance. We present SoNIC, a system that enables resource-limited sensor nodes to detect the type of interference they are exposed to and se-lect an appropriate mitigation strategy. The key insight un-derlying SoNIC is that different interferers disrupt individual 802.15.4 packets in characteristic ways that can be detected by sensor nodes. In contrast to existing approaches to inter-ference detection, SoNIC does not rely on active spectrum sampling or additional hardware, making it lightweight and energy-efficient. In an office environment with multiple interferers, a sen-sor node running SoNIC correctly detects the predominant interferer 87 % of the time. To show how sensor networks can benefit from SoNIC, we add it to a mobile sink appli-cation to improve the application’s packet reception ratio under interference