Cognitive radio paradigm has been identified as thesolution to spectrum underutilization. It promises to changethe face of spectrum management from planning, allocationand subsequently and most importantly utilization. Thepresent command and control approach in allocatingspectrum has been found to be ineffective. Thisinefficiency has lead to a perceived spectrum scarcity.Spectrum occupancy measurements have disputed this fact;through these measurements it has been found that thespectrum is actually underutilized. Thorough understandingof the allocated spectrum will go a long way towards thesuccessful deployment of cognitive radio paradigm.