Strategic Behavior of Cognitive Radio Networks with Different Information

The equilibrium joining probabilities for a single primary-user (PU) and secondary-users (SUs) in the case of no-information, and the equilibrium Nash balance thresholds for PU and SUs to join the system in the cases of partial-information and full-information observed by PU and SUs are investigated in a cognitive radio system with both of a PU buffer and a SU buffer. PU stochastically sends PU requests and each SU is assumed to only carry one SU request. Whenever a PU (or an SU) request is completed, an award is issued to the PU (or the SU). However, a holding cost is charged also for each SU and PU during their average sojourn time in the system respectively. Both of PU requests and SU requests are selfish in this research and their objectives are to maximize their own benefit. Our major conclusion includes that a threshold probability value for PU (or SU) to join the PU buffer is identified for the case of no-information, a Nash balance PU (SU) threshold value of number in PU buffer (SU buffer) is determined for the case of partial-information when an arriving PU (SU) request may join in the PU (SU) buffer; and the multi-dimensional Nash balance threshold integer values of SU number in SU buffer are established for the case of full-information when an arriving SU may join in the SU buffer. These Nash balance threshold integer values depend on not only the Nash Balance PU-threshold value but also the specific number of SU requests in the SU buffer at that arriving time. In addition, we discuss the sensibility of input parameters to the obtained equilibrium joining probabilities and Nash balance thresholds. We observe that SUs' equilibrium joining probability does not necessarily increase with the transmission rate of PU in no-information case and the Nash balance thresholds adopted by an arriving SU are fickle with the change of PU's transmission rate in both of partial-case and full-information case. Our results and observations provide a guideline and important managerial insights in making decisions with strategic users in the design of CRNs