Informed spectrum usage in cognitive radio networks: Interference cartography

This paper introduces interference cartography, a simple and effective concept that helps detect, identify and use spectrum opportunities in a secondary spectrum usage context. Interference cartography combines measurements performed by different network entities (mobile terminals, base stations, access points) with the geo-location information and applies simple and effective spatial interpolation techniques to achieve a map which indicates the level of interference experienced at each mesh over the area of interest. Using this information, a secondary network can detect the presence of a primary network (or of other secondary networks) and can use spectrum opportunities without causing harmful interference to them. As an example, a reliable spatial interpolation technique, kriging, is applied to interference data obtained from a radio network simulator. Obtained results demonstrate that interference cartography is a promising concept that can enhance the performance of secondary spectrum usage.