Dynamic spectrum access with preemption in open spectrum wireless networks

Analytical formulations of dynamic spectrum access (DSA) with and without preemption for two radio systems are presented. The DSA without preemption model is solved explicitly using a two-dimensional Markov chain while the DSA with preemption models are solved numerically using a two-dimensional Markov chain. Grades of service (GoSs) like system airtime, blocking probabilities and preemption probabilities are considered. The performance of these GoS measures and the effect of the size of the number of frequency channels are evaluated. Numerical results illustrate that higher gain in airtime and zero blocking probability for the prioritized radio system are achieved through preemption of the non-prioritized radio system¿s frequency channels.