Quantitative assessment of TV white space in India

Licensed but unutilized television (TV) band spectrum is called as TV white space in the literature. Ultra high frequency (UHF) TV band spectrum has very good wireless radio propagation characteristics. The amount of TV white space in the UHF TV band in India is of interest. Comprehensive quantitative assessment and estimates for the TV white space in the 470-590 MHz band for four zones of India (all except north) are presented in this work. This is the first effort in India to estimate TV white spaces in a comprehensive manner. The average available TV white space per unit area in these four zones is calculated using two methods: (i) the primary (licensed) user and secondary (unlicensed) user point of views; and, (ii) the regulations of Federal Communications Commission in the United States. By both methods, the average available TV white space in the UHF TV band is shown to be more than 100 MHz! A TV transmitter frequency reassignment algorithm is also described. Based on spatial-reuse ideas, a TV channel frequency allocation scheme is presented which results in insignificant interference to the TV receivers while using the smallest bandwidth for existing transmission across the four zones. In the proposed reassignment, it is found that four TV band channels (or 32 MHz) are sufficient to provide the existing UHF TV band coverage in India.