Wi-Fi's Energy Detection: A Study of Regional Regulations on Clear Channel Assessment

This paper presents an experimental evaluation of the energy detection mechanism in a commercial Wi-Fi Access Point (AP). Clear Channel Assessment (CCA) is a mechanism employed by Wi-Fi to sense if the medium is busy before trans-mitting. We investigate the CCA mechanism of the device under North American and European settings in response to broadband and narrowband Gaussian interference signals transmitted from a Universal Software Radio Peripheral (USRP). Given that CCA is a key mechanism in Wi-Fi's deployment, our study provides insight into the co-existence of Wi-Fi with itself and other wireless technologies. Our work demonstrates more rigid implementations in CCA in the European regions than in North American regions which sheds light on how regional regulations may differ and take precedence over standards compliance. We also show that under the North American implementation, the Energy Detection Threshold (EDT) of the device can be increased, effectively enabling Wi-Fi to transmit over neighboring narrowband and broadband traffic.