Date Added: Nov 2012
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 random spectrum availability. In this paper, the authors consider a single channel CRN with centralized control, operating over a time-slotted primary network, accessing the channel at the spectrum holes without interfering with primary users. The central controller transmits elastic data traffic to the Secondary Users (SUs). The service response time is an important QoS parameter for elastic data traffic, defined as the duration from the instant that an SU requests a data file from the central controller until it completes the reception.