Cognitive Radios and Cognitive Networks: A short Introduction

Radio spectrum is the most valuable resource in wireless communication. The cognitive radio and cognitive based networking are transforming the static spectrum allocation based communication systems in to dynamic spectrum allocation. Cognitive radios are intelligent devices with ability to sense environmental conditions and can change its parameters according to the requirements to get the optimized performance at the individual nodes or at network level. This paper covers the basics and origin of software defined radio, cognitive radio, cognitive radio network, cognitive cycle, performance metrics and the concept of cross layer design. The performance metrics explain the node and network level performance measurements. This paper also covers the different network paradigms.