This paper presents results from spectrum occupancy measurements in the 2.3-2.4 GHz band at Turku, Finland and Chicago, USA. The band is currently under study in European regulation and standardization for mobile communication systems. We review the recently introduced Licensed Shared Access (LSA) concept as a potential means for making the 2.3-2.4 GHz band available for mobile communications on a shared basis while protecting the rights of the incumbent spectrum users. The spectrum occupancy measurements conducted in one location in Finland show that the use of this band is rather low indicating that there might be potential for mobile communication systems to share this band with the incumbents under the LSA approach.
White spaces are locally or temporally available frequencies that are principally reserved for primary use such as TV broadcasting. The currently prevalent view to the utilization of such spectrum resources is that white space devices must query a geolocation database to obtain information about available frequencies and related maximum transmission powers. A geolocation database is fundamentally based on field strength estimates of the primary service obtained using radio propagation models. However, field strength estimates for geographically extensive broadcast networks are typically computed for spatial resolutions of hundreds of square meters. Therefore, even with the most sophisticated propagation models currently available, the predicted values always contain errors due to the limited geographical information. To overcome such deficiency, we propose a geostatistical approach for estimating the radio environment based on universal kriging interpolation. In addition, we optimize the locations of field measurements using spatial simulated annealing, and show that it improves significantly local field strength estimates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.