Dynamic spectrum access in heterogeneous networks

Abstract

The next generation of radio wireless networks is expected to support spectrum decision operations that will allow a cognitive radio terminal to share the frequency bandwidth with primary users without impairing their QoS requirements. This can indeed enhance the utilization of the limited spectrum resources, and help meet the growing bandwidth demand. In this paper, we propose a new, cross-layer algorithm that allows a cognitive terminal to share and access to either HSDPA or WiMAX licensed spectrum while giving priority to the primary users. This algorithm not only considers the interference caused by the cognitive terminal, but also enhances the achievable throughput of this cognitive terminal. Simulation results show the effectiveness of our spectrum access scheme. Under our proposed scheme, the achievable data rate of the cognitive radio terminal is increased by 30% when compared with that obtained under common access schemes.

Application-aware dynamic spectrum access

“…We take this general view of DSA here, in which, apart from switching channels, access mechanisms (or the MAC-PHY protocols) may also need to be dynamically changed in order to accommodate different wireless characteristics of various spectrum bands. The FCC's establishment of rules that open up TV bands for DSA [5] has stimulated efforts in advancing technologies for DSA across other licensed bands [10,11].…”

The Problem of Sensing Unused Cellular Spectrum

“…In this paper, we address spectrum licensed to another set of primary users -cellular telephony operators. Our focus on cellular bands is justified given the significant recent interest in implementing DSA in these bands [2][3][4][5]8]. Such interest is fueled by the large number of devices and networks using cellular bands.…”