Protecting the primary users´ operational privacy in spectrum sharing

Although using geolocation databases is a practical approach for enabling spectrum sharing, it poses a potentially serious privacy problem. Secondary users (queriers), through seemingly innocuous queries to the database, can determine the types and locations of incumbent systems operating in a given region of interest, and thus compromise the incumbents´ operational privacy. When the incumbent systems (primary users) are commercial systems, this is typically not a critical issue. However, if the incumbents are federal government systems, including military systems, then the information revealed by the databases can lead to a serious breach of operational privacy. In this paper, we propose privacy-preserving mechanisms and techniques for an obfuscated geolocation database that can enable the coexistence of primary and secondary users while preserving the operational privacy of the primary users.