Analysis of Optimal Random Access for Broadcasting with Deadline in Cognitive Radio Networks

This letter considers optimal random access scheme for broadcasting in cognitive radio network where multiple secondary users (SUs) contend to access the channel based on the slotted-Aloha with a common access probability. SUs try to opportunistically send broadcast messages to their neighbors using the time slots unused by primary users (PUs). It is assumed that broadcast message is neither acknowledged nor retransmitted and further has a strict delivery deadline. In this scenario, we consider successful delivery probability of message within the delivery deadline as performance measure of interest. The objective is to explicitly obtain the optimal access probability maximizing the successful delivery probability.