Quantitative assessment of TV white spaces for cognitive radio networks in India

Abstract

The terrestrial TV spectrum has long been underutilized in India. In spite of large spectrum allocation, very small spectrum is used at any time and space. The Telecom Regulatory Authority of India (TRAI) and Dept. of Telecommunications (DoT), according to plan proposal of year 2011, have proposed to allocate some portion of the TV spectrum to IMT-A services after the complete digitization of terrestrial TV transmission. For deployment of CRN operating on TV white spaces (TVWS), quantification of TVWS is a necessary exercize. After complete digitization, many different kind of services such as community TV and radio, education services, health services, etc are expected to operate in TV band along with the digital terrestrial TV transmission (DTTV). Although, the complete digitization is not yet over, the regulating authority of India has planned to keep the same band structure as that of analog TV, even after digitization in initial phase. This is planned to be done by accommodating digital channels in the old analog channels. This fact motivates to carry out an assessment of TVWS capacity before and after complete digitization. This paper undertakes the quantitative study of TVWS by taking field strength measurements for 174–230 MHz and 470–806 MHz UHF band (includes band III band IV on representative area in a geo-spatial region (Pune Region, India). The TVWS capacity is calculated from field strength measurements in terms of number of channels that are empty at specific location and time and the average capacity is calculated with respect to certain spectral efficiency.