Co-existence of TV broadcast and wireless systems for public safety networks in the TV white space

The spectrum sharing between primary TV systems (Channels 9 and 35) and Public Safety Networks (PSNs) is presented in this article. The networks to be deployed within Television White Space (TVWS) in Ilorin metropolis of Kwara State operate on a secondary basis spatially, without causing harmful interference to incumbent TV users. In order to guarantee the protection of incumbent TV users both in VHF and UHF bands, minimum separation distances were suggested considering field  strengths of 36 dBu and 41 dBu as the protected contours for the two bands  respectively. The effects of varying the transmit power and the antenna height of the secondary system on the coverage area are emphasized in this work. Aggregate interference effect from the multiple secondary systems on the TV service coverage was also investigated. The performances of VHF and UHF bands were also verified when used for secondary transmission both at lower and higher transmit power scenarios. The results of this work show that the safety networks can co-exist with the TV systems without causing harmful interference with the suggested separation distances at the edge of the noise-limited service area, where the signal-to-noise ratio is 16 dB as recommended by the International Telecommunication Union-Radio sector (ITU-R). Keywords : PSN, TV systems, Signal-to-Noise Ratio, TV White Space, Service coverage.