An Analytical Performance Model of Opportunistic Spectrum Access in a Military Environment

In an opportunistic spectrum sharing system, secondary users equipped with cognitive radios opportunistically access spectrum that is not being used by the primary users, i.e., the licensed spectrum users, without causing harmful interference to the primary users. We present an analytical performance model of opportunistic spectrum access in a military environment consisting of a group of secondary users sharing a set of channels with primary users in a coverage area. A secondary user occupying a given channel detects when a primary user accesses the channel and then either moves to another idle channel or is placed in a virtual queue where it waits until either a channel becomes available or a maximum waiting time is reached. Using a two-dimensional Markov model, we derive expressions for the blocking probabilities and reconnection probability and evaluate the performance metrics under a range of parameter settings.