SpectraMap: Efficiently Constructing a Spatio-temporal RF Spectrum Occupancy Map

摘要

The RF spectrum is typically monitored from a single, or few, vantage points. A larger spatio-temporal view of spectrum occupancy, such as over a few weeks on a city-wide scale, would be beneficial for several applications, for example, spectrum inventory by regulators or spectrum monitoring by wireless carriers. However, achieving such a view requires a dense deployment of spectrum analyzers, both in space and time, which is prohibitively expensive. In this paper, we present a novel efficient approach to obtain an accurate extrapolated spatio-temporal view of spectrum occupancy. Our method uses RSSI measurements alone and does not require a-priori information of terrain, transmitter location, transmit power or path-loss model. We present our method as an algorithmic framework, called SpectraMap, which through targeted deployment of both static and mobile spectrum analyzers, gives a view of the spectrum occupancy over both time and space. We contrast SpectraMap's accuracy with that of Krig-ing (an accepted well performing method of RSSI spatial extrapolation) through simulations and present RSSI map construction savings achieved through actual deployment on a large university campus. Finally, we draw a theoretical distinction between SpectraMap and relevant contemporary solutions in the fields of space-time RSSI maps and spectrum management.