Comprehensive study of spectrum occupancy for 802.11b/g/n homogeneous networks

This paper presents a scheme for comprehensive experimental measurements of Wi-Fi networks spectrum occupancy in the ISM band. The work presented herein provides duty cycle measurements for single and multiple communicating Wi-Fi pairs. Duty cycle results are provided for 802.11b, g and n Wi-Fi standards at different throughput levels. Lower values were observed for 802.11b and g networks. Spectrum occupancy measurements are essential for wireless networks planning and deployment. This comes as a consequence of the ever increasing demand for spectrum to accommodate newly deployed wireless systems [1]. Duty cycle serves as a measure for spectrum busyness. Higher duty cycle levels directly impact other wireless links, which either refrain from transmission or suffer from increased errors. Such measurements assist other technologies in mitigating interference effects suffered from Wi-Fi by varying transmission parameters to accommodate measured duty cycle. Measurements also enable improved spectrum planning for the overcrowded 2.4GHz Industrial Scientific and Medical ISM band. Measurements were carried and validated using developed tools in both time domain and frequency domain. Results have shown that duty cycle is able to reach up to 98.9% with 802.11n three-communicating pairs.