Distributed Opportunistic Spectrum Access Networks: From Theory to Practice

Abstract—Opportunistic Spectrum Access (OSA) is foreseen as the future of wireless communications. OSA relies on the cognitive radio transceiver that tracks the spectral opportunities over a wide spectrum range (multiple GHz). The cognitive radio should be able to analyze the huge amount of acquired spectral information, decide the best course of action, and reconfigure its transceiver parameters accordingly in a very short time due to the highly dynamic nature of the radio environment. This poses stringent requirements on the hardware and processing power of the transceiver. Despite the recent advances in the radio transceiver technologies, existing radios do not allow for exploiting OSA to its full potential. Furthermore, the absence of a centralized entity that controls the spectrum access decisions in distributed ad-hoc networks makes implementing OSA more challenging. In this article, we experimentally demonstrate the ability of implementing distributed OSA schemes given the practical limitations of existing low-cost transceiver technologies. Furthermore, we evaluate the performance of different OSA approaches. I