Stability of queues in multi-user cognitive radios

We study the behavior of Queues in multi-user cognitive radios with several channel sensing order selection strategies. We consider three different mechanisms to resolve contention between cognitive users (CU), COLLISION, BACKOFF and PRIORITY. For each mechanism, we find the optimal channel sensing order for each CU, which maximizes the total cognitive users’ throughput. We also consider a simple cyclic sensing mechanism to sense the channels. Under each channel sensing mechanism, we study the stability of queue for each CU by changing the packet arrival rates of each CU. Our results show that when optimal sensing order is used the stability region is bigger compared to the cyclic sensing order.