Guaranteed service and delay-constrained capacity of a multi-channel cognitive secondary network

In this paper, we consider a multi-channel cognitive radio system serving a primary network and a secondary network, and analyze the quality of service and delay-constrained capacity of the secondary network. Specifically, by assuming that a certain amount of resource is exclusively reserved and used on each channel by the primary network, we derive the traffic transportation capacity that is guaranteed to the secondary network. Based on this, we analyze the traffic delay distribution in the secondary network and derive an upper bound on it, which allows us to further obtain a guaranteed capacity of the secondary network in serving traffic with probabilistic delay requirement. Both numerical and simulation results are presented for an example where the secondary network traffic follows a model taken from 3GPP LTE. The delay distribution, average delay and delay-constrained capacity of the secondary network are compared. The excellent match between analytical results and simulation results validates the theoretical analysis.