Toward Practical Spectrum Permits

Abstract

As spectrum is being released from legacy technologies, reforms in policies and regulations promise to spur wireless growth by distributing spectrum dynamically across wireless networks matching their traffic demands. However, a major obstacle to its adoption remains. There is no effective solution to protect licensed users from spectrum misuse , where users transmit without properly licensing spectrum, and in doing so, interfere and disrupt legitimate flows to whom the spectrum is assigned (and sold). In this paper, we discuss an initial step toward enforcing dynamic spectrum allocation using the concept of spectrum permit , where authorized spectrum users embed secure spectrum permits into data transmissions, enabling patrolling trusted devices to detect devices transmitting without authorization. We highlight the development of spectrum permits, and describe Gelato , a spectrum misuse detection system that minimizes both hardware costs and performance overhead on legitimate data transmissions. We implement Gelato using USRP2 with laptops and lower cost RTL-SDR devices with smartphones. We show that both implementations are robust against attacks and can reliably detect spectrum permits in real time.