Performance evaluation of three dynamic channel access strategies for spectrum leasing in CRNs

Spectrum leasing in cognitive radio networks (CRNs) allows the primary network (PN) to lease a certain fraction of its licensed bandwidth to the secondary network (SN). The motivation for such a concept is to enhance the performance of SNs while improving channel utilization. Meanwhile, the license owners of the channels can also gain benefits through spectrum leasing in terms of either monetary rewards or cooperative communications. In this paper, we propose three dynamic channel access strategies for spectrum leasing in multi-channel CRNs. A common characteristic of all these strategies is that the priority for channel access over the leased spectrum is given to SNs and the unleased spectrum to PNs respectively. The distinction among these three strategies is at the level of opportunistic or exclusive access to leased and unleased spectra by an SN or a PN. The performance of the proposed strategies is evaluated and compared with each other in terms of several system centric metrics including capacity, blocking probability, forced termination probability and channel utilization efficiency.