Metrics for short-term radio signal disturbances detection in wireless sensor networks

Passive radio transmission interferences such as moving or stationary objects may cause temporal signal fading in the radio propagation environments of wireless sensor networks (WSN) and lead to link quality degradation. The short-term signal disturbances cause a major concern especially in industrial environments with continually incoming and outgoing trucks, moving around forklifts and workers, as well as large concrete and metal surfaces. We have studied the effects of certain environmental disturbances on the quality of the transmitted signals and applied different metrics to characterize the signal degradation. The objective was to find out if the received radio signal characteristics in the form of Received Signal Strength Indicator (RSSI), Bit-Error-Rate (BER) and Probability Density Function (PDF) of the received signal magnitude could be used to detect passive radio disturbances, and how these measurement results can be utilized to overcome the transmission problems. The results of our study show that RSSI and BER metrics can be used to detect and PDF values to further characterise the passive radio interferences disturbing radio transmission.