SAMAR — Spectrum Aware token MAc for Cognitive Radio Networks

Cognitive radio network (CRN) is one of theprominent technology for the next generation wirelessnetworks. Due to the CR version, the userswere classified into two types which are the primaryusers (PUs) and secondary users (SUs) which arealso named as licensed and unlicensed users. Themain objective of CRN is to access the underutilizedlicensed bands of PUs by SUs without any interferenceto the PUs transmission. In the CR technology, medium access control (MAC) plays a vital role toincrease the spectrum efficiency and also minimizethe collisions among SUs. So to design an efficientMAC is one of the significant challenges in theCRN. The existed MAC protocols are unable toidentify the most appropriate spectrum to access. Thus, spectrum aware token based MAC protocolis proposed to resolve the spectrum selection issuein MAC design for CRN. In this paper, we considerexpected spectrum stability time (ESST) as a metricto assign ranks to the available licensed spectrumbands. Simulation results for various parametersshow that SAMAR protocol can approximately improvethroughput 8% decrease transmission delay75% compared with IEEE 802.11n. The remainingmetric results have demonstrated the performanceof existed MAC protocols like IEEE802.11n andTMAC with the proposed MAC.