Collision Probabilities for Dynamic Spectrum Access with Cognitive Radios

Dynamic spectrum access is pointed as a promising alternative to mitigate spectrum scarcity, permitting the development of new communication technologies, with more efficient spectrum usage. In this context, cognitive radios can be employed to allow spectrum access in an opportunistic manner. In this work we present analytical and simulated results for collision probabilities of secondary users sharing a portion of spectrum with licensed users. We consider a non-intrusive overlay configuration, with primary access occurring at any time, and secondary access based on periodic spectrum sensing. Our analysis includes different traffic, detection probabilities and interval between consecutive sensing events.