This document discusses cognitive radio networks (CR). CR networks are defined as networks that are aware of their surroundings and can dynamically reconfigure their characteristics. The document outlines topics that will be discussed including CR antennas, mechanisms, accessibility, adaptivity, scalability, reliability and interconnectivity. It provides examples of how CR networks improve these qualities and can sense spectrum usage, analyze it, decide on parameters, and tune transmissions accordingly using reconfigurable antennas. The document compares CRs to conventional radios and outlines benefits of CRs such as functioning in challenging conditions and identifying unused spectrum. It mentions xG Technology developed CR network technology called xMax.