Shades of White: Impacts of Population Dynamics and TV Viewership on Available TV Spectrum

Current regulations leave a few television (TV) white spaces in populated urban areas where spectrum shortage is mostly experienced. As TV set feedback becomes essential in the next generation terrestrial TV standard, an opportunistic TV spectrum sharing based on TV receiver activity information and transmit power control is proposed to exploit the underutilized active TV channels. Based on investigation of the spatial–spectral–temporal characteristics of TV receiver activities, analytical models are developed to capture the spatio-temporal distributions of available spectrum and corresponding capacity. The influence of multiple factors, such as feedback delay, spectrum handover overhead, ranking order, and distribution of TV channel popularity are discussed and modeled. The proposed power control mechanism is verified through experiments at representative campus and residential environments. Empirical data-based simulations and geographic analyses are conducted to evaluate the developed models and further profile the spectrum opportunities within a cell, across New York city (NYC) and other 273 cities in the United States. In NYC, the proposed solution provides a <inline-formula><tex-math notation="LaTeX">$3.8$</tex-math></inline-formula>–<inline-formula><tex-math notation="LaTeX">$11.7$</tex-math></inline-formula>-fold increase of average spectrum availability, and <inline-formula><tex-math notation="LaTeX">$2.5$</tex-math></inline-formula>–<inline-formula><tex-math notation="LaTeX">$6.6$</tex-math></inline-formula>-fold increase of capacity from current regulations. By investigating the feasibility and prospects of this approach, this paper intends to motivate further discussions in policy, business, and privacy aspects to reach its significant potential.