Methodological aspects of spectrum occupancy evaluation in the context of cognitive radio

Several spectrum measurement campaigns have been performed in diverse locations and scenarios in order to assess the degree to which spectrum is currently used in real wireless communication systems. Although such measurement campaigns follow similar approaches, there is a lack of common and appropriate evaluation methodology, which would be desirable not only to prevent inaccurate results but also to enable the direct comparison of results from different sources. In this context, this work presents a comprehensive and in-depth discussion of several important methodological aspects to be accounted for when evaluating spectrum occupancy. Moreover, a quantitative evaluation of the impact of different factors on the obtained results and various useful guidelines are also provided. The results presented in this work highlight the importance of carefully designing an appropriate methodology when evaluating spectrum occupancy in the context of cognitive radio.