Chapter 11 - Network Support: The Radio Environment Map

Abstract

This chapter discusses the motivation and the important role of network support in cognitive radios. It introduces the radio environment map (REM) and explains how the REM can provide network support to cognitive radios for various applications. The chapter addresses the important role of network support in developing cognitive radios for various application scenarios, including infrastructure-based as well as infrastructure-less ad hoc networks. As a vehicle to providing network support to cognitive radios, the REM is proposed to be an integrated database that consists of multi-domain information, such as geographical features, available services, spectral regulations, locations and activities of radios, policies of the user and/or service provider, and past experience. A cognitive engine to enhance or achieve most cognitive functionalities, such as reasoning, learning, planning, and decision support, can exploit REM. Leveraging both internal and external network support through global and local REMs presents a sensible approach to implement cognitive radios in a reliable, flexible, and cost-effective way. The REM presents a smooth evolutionary path from the legacy radio to the cognitive radio. The REM can be viewed as a natural, but major evolution of radio resource management used in today's commercial wireless networks.