Cognitive MAC protocols are designed to efficiently utilize the scarce spectral resources
without affecting the performance characteristics of primary users. The use of spectrum
opportunities can often require stochastic approaches due to difficulty in predicting their
appearance. Infrastructure based coordinated access techniques are not viable for many
applications and spectrum bands, especially in the case of wireless local area and sensor
networks. In this article, we describe CogMAC, a decentralized cognitive MAC protocol …

The rapidly increasing number of wireless applications are making the wireless spectrum
scarcity a serious problem. Cognitive MAC protocols have emerged as a promising solution
to address this issue by opportunistically allowing secondary users to utilize unused
licensed bands, and enabling spectrum co-existence of multiple secondary networks. In this
paper, we present CogMAC+, a decentralized multichannel MAC protocol, which is based
on multichannel preamble reservation scheme and CSMA principle. It achieves parallel …