On-off Voice Capacity of Single-hop Cognitive Radio Networks with Distributed Channel Access Control

Cognitive radio networks (CRNs) have emerged as a promising solution to spectrum under-utilization and congestion. Supporting quality of service (QoS) aware services over CRNs is always challenging due to the randomness of the spectrum availability. In this paper, we consider a set of fully-connected cognitive radios (secondary users) operating over a time-slotted primary network, accessing the channel at the spectrum holes without interfering with primary users. As the capacity analysis is one of the basic steps to guarantee QoS, we analyze the on-off voice capacity of single-channel single-hop fully-connected CRNs under distributed channel access control. The voice capacity is represented in terms of the number of simultaneous independent voice calls that the secondary network can support, providing stochastic delay guarantee. Our analytical results have a close match with the simulation results. With proper medium access control, capacity analysis can help to develop a call admission control policy for QoS provisioning in non-fully-connected CRNs.