Opportunistic usage of TV band for multiple secondary WLAN users

This paper analyzes the possibility to introduce a WiFi type of secondary network containing multiple secondary access points (SAPs) in TV bands. In particular, the analysis investigates the limitations of TV whitespace (TVWS) usage imposed by the aggregate interference of the secondary users towards the primary and secondary system, assuming different levels of penetration of the TVWS-operating technology. The implementation of CSMA/CA MAC protocol within the secondary network has a high impact on the tolerable density of SAPs, as well as on the achievable throughput. The introduction of different TVWS sharing management can improve the secondary network deployment density and its throughput. However, the study reveals that the secondary system performance is poor regarding the achievable throughput in cases when densities of SAPs are high and comparable to the current WiFi technology penetration in urban areas.