The need for the radio frequency (RF) spectrum for the rapidly growing broadband access services is evident. Abundant and fast access to spectrum has three main advantages: it fosters rapid innovation in wireless systems and services lowering entry barrier on the market; it enables affordable mobile broadband access to all; and makes new energy efficient wireless systems possible. Secondary use of already licensed, but poorly used spectrum, (Cognitive Radio )has been proposed as a solution to make more efficient use of the spectrum. Low spectrum occupancy in a number of measurement campaigns worldwide has been the basis for claims of large gains in spectrum efficiency by cognitive radio. However, little research has been done to actually substantiate these claims.
QUASAR is an FP7 targeted research project (STREP) that brings together a highly competent team of manufacturers, operators, regulators and universities with the aim at bridging this gap between the claims made in traditional cognitive radio research and practical implementation by assessing and quantifying the “real-world” benefits of secondary (opportunistic) access to primary (licensed) spectrum. The analysis is based on two key features of cognitive radio: the ability of the secondary users to discover the opportunity to use the spectrum, and assessing the electromagnetic impact of secondary user transmissions on primary system (receivers).
