Dynamic spectrum access [Guest Editorial]

The transformation of dynamic spectrum access (DSA) from theory into practice has begun - regulatory decisions such as the recent U.S. FCC "TV White Space Order" embrace DSA, standards bodies have ratified DSA enabling standards, commercial DSA devices are now available, and numerous DSA prototypes, such as DARPA\´s XG, have been demonstrated. As networks and devices increasingly gain intelligence and "cognitive" capabilities, and regulators around the world seek to enhance spectrum utilization, dynamic access is becoming one of the most important but most complex topics in wireless communications development. Such spectrum access methods present numerous challenges that broadly span technology, economics and public policy.