Moving toward higher speed WLANs through dynamic spectrum access in the unlicensed band

In this paper, we consider the issue of using cognitive radio as an enabling technology for increasing the data rate in WLANs. Cognitive radio has conventionally been designed to yield the channel when the presence of primary users is detected. However, such a behavior significantly impacts the service provided when it is used as a technology for higher speed WLAN access. We identify the problem and propose a coordinated channel access mechanism with CSMA/CA-aware scheduling to allow for bandwidth sharing among cognitive radio enabled nodes and legacy 802.11 nodes in the unlicensed band. Simulation results show that, with the help of the proposed CSMA/CA-aware scheduling, cognitive radio has potential to be used as the enabling technology for high speed WLAN access in the unlicensed band.