Radio Environment Maps And Its Utility In Resource Management For Dynamic Spectrum Access Networks

Recent measurements on radio spectrum usage have revealed the abundance of under-utilized bands of spectrum that belong to licensed users. This necessitated the paradigm shift from static to dynamic spectrum access (DSA). Researchers argue that prior knowledge about occupancy of such bands, such as, Radio Environment Maps (REM) can potentially help secondary networks to devise effective strategies to improve utilization. In the chapter, we discuss how different interpolation and statistical techniques are applied to create REMs of a region, i.e., an estimate of primary spectrum usage at any arbitrary location in a secondary DSA network. We demonstrate how such REMs can help in predicting channel performance metrics like channel capacity, spectral efficiency, and secondary network throughput. We show how REMs can help to attain near perfect channel allocation in a centralized secondary network. Finally, we show how the REM can be used to perform multi-channel multi-hop routing in a distributed DSA network