nROAR: Near Real-Time Opportunistic Spectrum Access and Management in Cloud-Based Database-Driven Cognitive Radio Networks

摘要

Cognitive radio network with spectrum sensing to find idle channels and access them opportunistically is regarded as an emerging technology to deal with spectrum scarcity caused by exclusive licensing to primary systems. Simulation-based studies loose practical relevance due to assumptions and usage of simple models for defining transmission regions, multi-path propagation, and traffic intensity. In this paper, we present an experimental study for near real-time spectrum sensing and opportunistic spectrum access in database-driven cognitive radio networks (nROAR) using national instrument USRP devices in wide-band regime. We present numerical results for evaluating spectrum sensing using adaptive threshold-based joint energy and bandwidth detection. Furthermore, we evaluate the dynamic spectrum access using database-driven quorum-based rendezvous for opportunistic access for admitted unlicensed secondary users in diverse wireless bands. The proposed nROAR architecture addresses challenges related to providing spectrum access which require fast processing of a large number of spectrum-sensing measurements across diverse wireless bands, geography, and time.