Assessment of white spaces quality in rural areas : a large-scale spectrum survey

Spectrum is a valuable resource for broadcasting and wireless communications. Despite the fact that most of the sub-1-GHz spectrum is granted, spectrum surveys in suburban areas reveal a poor usage efficiency (less than 20% on average). Cognitive Radio for 56 next generation radio is a potential technology for dynamically exploit the spectrum white spaces, particularly in low populated rural areas. However, not all the empty spectrum is useful for providing broadband wireless connectivity guaranteeing a certain Quality of Service (QoS) or without causing harmful interference to the primary licensed services. In this paper we perform a large scale -spectrum survey and measurement campaign in two rural areas. We also quantify the white spaces and its real potential for secondary services. Our research reveals that, on average, less than 11% of the spectrum is in use in the surveyed rural areas. However, in one area only 60% of the white spaces can be used for a commercial service