Distributed Precedence Queuing for Efficient Spectrum Management in Cognitive Radio Networks

Abstract

Priority queue-based techniques improve spectrum efficiency by allocating the underutilized spectral bands (holes) of primary users to secondary users in Cognitive Radio Networks (CRN). This article proposes a Distributed Precedence Queuing scheme for Efficient Spectrum Management (DPQESM) in CRNs. The proposed method classifies the available channels into periodic and aperiodic based on the state of active primary user nodes. For each channel, the probability distribution of primary users, secondary users, hidden primary nodes and allocation cost are evaluated. This approach improves the channel utilization factor and frequency reuse in CRN. Distributed precedence factors of secondary user nodes are evaluated in terms of input signal power, average reuse factor, redeemable power rate and channel availability. The proposed DPQESM scheme evaluates channel allocation cost per session which is a function of power levels, available spectrum slots on each channel, average channel access time and packet size. This approach further optimizes the spectrum allocation in the network. Simulation results indicate that the channel allocation costs are reduced for the proposed DPQESM scheme as compared to the existing distributed probability and simple queue-based methods in CRN.