Chicago spectrum occupancy measurements & analysis and a long-term studies proposal

This paper describes spectrum occupancy measurements performed in Chicago, IL in November 2005 and proposes long-term studies in multiple locations. The Chicago project consisted of deploying a high dynamic range spectrum measurement system, a data collection and processing system and conducting spectrum occupancy measurements in all bands between 30 MHz and 3,000 MHz (see Figure 1). These measurements were taken over a two-day period and are added to an existing body of data compiled in other cities and regions including Washington, D.C., and New York City. While these studies are critical in determining what bands have low utilization, longer-term studies are crucial in developing new spectrum access technologies such as cognitive radio algorithms related to Dynamic Spectrum Sharing (DSS). The observed low spectrum occupancy in a business center like Chicago indicates that a DSS radio system could access a huge amount of "prime" spectrum. The unoccupied, large contiguous spectrum blocks show that DSS radios can use conventional contiguous waveforms and that high temporal agility may not be required to significantly expand the data capacity of an accessible section of spectrum. From both short-term and long-term spectrum occupancy studies, candidate bands for spectrum sharing can be readily identified along with unique signal characteristics within these bands. The most important use of the data will be to support senior U.S. (and non-U.S.) government officials in taking action to enhance the use of the currently under utilized RF spectrum resources and to make the R&D investments and policy changes needed to support the development of dynamic spectrum sharing radios.