Primary-prioritized Markov approach for dynamic spectrum allocation

TLDR

Dynamic spectrum access is a promising way to fully utilize scarce spectrum resources, and accounting for users’ access statistics in a changing environment is essential for efficient allocation. The study proposes a primary‑prioritized Markov approach that models primary–secondary user interactions as continuous‑time Markov chains for dynamic spectrum access. Using the CTMC models, the authors derive optimal access probabilities for secondary users to compensate throughput loss from interference, thereby coordinating access and capturing spectrum dynamics. Simulations demonstrate that the primary‑prioritized approach achieves a favorable trade‑off between spectrum efficiency and fairness, delivering higher throughput than CSMA‑based and max‑min fairness methods while maintaining fair sharing with minimal performance loss compared to throughput‑maximizing schemes.

Abstract

Dynamic spectrum access has become a promising approach to fully utilize the scarce spectrum resources. In a dynamically changing spectrum environment, it is very important to consider the statistics of different users' spectrum access so as to achieve more efficient spectrum allocation. In this paper, we propose a primary-prioritized Markov approach for dynamic spectrum access through modeling the interactions between the primary and the secondary users as continuous-time Markov chains (CTMC). Based on the CTMC models, to compensate the throughput degradation due to the interference among secondary users, we derive the optimal access probabilities for the secondary users, by which the spectrum access of the secondary users is optimally coordinated, and the spectrum dynamics are clearly captured. Therefore, a good tradeoff can be achieved between the spectrum efficiency and fairness. The simulation results show that the proposed primary-prioritized dynamic spectrum access approach under proportional fairness criterion achieves much higher throughput than the CSMA-based random access approaches and the approach achieving max-min fairness. Moreover, it provides fair spectrum sharing among secondary users with only small performance degradation compared to the approach maximizing the overall average throughput.