A quantitative assessment of wireless spectrum measurements for dynamic spectrum access

In this paper, we provide a qualitative assessment of the spectrum usage across five geographically separated sites in four mid-size metropolitan centers located in the United States. Specifically, the variations in spectrum occupancy across space, time and frequency are investigated and compared between different sites within the city as well as with other cities. We show that the variation at different locations within the same city is considerably high. Furthermore, we present a simple four-state Markov model that characterizes time-varying behavior of the spectral occupancy of a frequency channel.