Privacy Preserving Scheme for Operating Frequency of Incumbents in Citizens Broadband Radio Service

Abstract

Citizens Broadband Radio Service (CBRS) is a new service band in 3550–3700 MHz spectrum with the federal military radars of the United States as the primary users (also called as incumbents). The privacy of location, operation time, operating frequency, and antenna parameters of the incumbents is crucial for national security. Different schemes have been proposed for ensuring location and operation time privacy of incumbents. However, the privacy of operating frequency of incumbents has not been addressed. The termination of non-incumbent device from a frequency on which the incumbent becomes active can reveal the operating frequency of the incumbent. In this work, we propose a scheme to preserve the privacy of operating frequency of the incumbents by introducing dummy incumbent channels. We analyze the probability of incorrectly identifying an actual incumbent channel by the adversary as the privacy metric for incumbents. Further, the optimum probability of faking the presence of incumbents on a channel is obtained through a trade-off between the privacy of incumbents and utility of non-incumbents for different system parameters. Finally, the proposed results are verified through simulations.