Opportunistic Spectrum Access via Periodic Channel Sensing

TLDR

The problem of opportunistic access of parallel channels occupied by primary users is considered. The study proposes a slotted transmission protocol for secondary users that employs periodic sensing and optimal dynamic access to opportunistically use channels occupied by primary users. Using a continuous‑time Markov chain model of primary‑user occupancy, the authors formulate a constrained Markov decision process, solve it with a linear program to derive the optimal access policy, and evaluate it via simulations. Periodic sensing yields negligible loss of throughput when the interference constraint is tight.

Abstract

The problem of opportunistic access of parallel channels occupied by primary users is considered. Under a continuous-time Markov chain modeling of the channel occupancy by the primary users, a slotted transmission protocol for secondary users using a periodic sensing strategy with optimal dynamic access is proposed. To maximize channel utilization while limiting interference to primary users, a framework of constrained Markov decision processes is presented, and the optimal access policy is derived via a linear program. Simulations are used for performance evaluation. It is demonstrated that periodic sensing yields negligible loss of throughput when the constraint on interference is tight.