Comparing historical and current spectrum occupancy measurements in the context of cognitive radio

Cognitive radio (CR) technology promises to be one possible solution to solve the problem of lack of frequency spectrum, by allowing access of unlicensed users in licensed bands, based on an opportunistic approach and without interfering with the licensed (primary) user. A fundamental key to the success of such an approach is knowledge of the statistical properties of the spectrum occupancy, which forms the basis of the current project. Numerous measurement campaigns have already been carried out in the USA and in other locations worldwide. These measurement campaigns have been performed at different locations in the context of cognitive radio. This paper collects together previous research work carried out worldwide and compares it with spectrum occupancy measurements recently undertaken at the University of Hull, UK.