Experimental method for testing effect of noise on Wi-Fi and Zigbee communication networks

This paper reports experimental method developed to measure effect of noise (White Noise) on communication networks operating in 2.4GHz band using Wi-Fi (IEEE802.11.bg) and Zigbee (IEEE802.15.4) protocols. Experimental setup consists of Wi-Fi / Zigbee communication link coaxially connected and operating in 2.4GHz band. A calibrated noise source is coupled to this link using directional coupler and 2.4GHz microwave isolator. Introduced noise in this link has wideband frequency noise spectrum over complete operational range of Wi-Fi, Zigbee communication radios. This introduced noise causes change in signal to noise ratio which affects the quality of communication link and results in higher bit error rate (BER). Higher bit error rate causes decrease in data transfer rate and hence poor link quality. Observed decrease in link quality with introduction of higher amplitude of noise is noted down. Percentile decrease in link quality due to introduced noise at different operational received signal strengths indicated (RSSI) are calculated and plotted.