Using radio-frequency pattern matching to nab terrorists

RFPM is the only high-accuracy, software-based, scalable location solution that requires no additional hardware changes or additions to the mobile device or at the base stations. It compares mobile measurements (e.g., signal strengths, signal-to-interference ratios, and time delays) against a geo-referenced database of the mobile operator's radio environment. RFPM works extremely well in non-line-of-sight conditions, such as dense urban and indoor environments, where GPS-based solutions face severe challenges. Because it is independent of line-of-sight conditions, RFPM is highly reliable and is ideal for the mission-critical and life-safety applications that governments increasingly face. RFPM technology is based on the observation that the radio environment varies from location to location, and each set of measured values will provide an RF signature that uniquely identifies a particular location. Because the control or overhead channels of a wireless network are broadcast at constant power, they provide a signature that is predictable and repeatable. The RFPM "location engine" consists of patented algorithms that estimate the location of the handset by comparing the time series of reported signal-strength measurements to the values stored in a patented database containing a detailed knowledge base of the surrounding terrain-its RF "fingerprint." With the ability to locate and monitor criminals and terrorists comes potential abuse of the privacy of ordinary citizens. To truly understand the potential threat to one's privacy, one must understand how and why location information is tracked or recorded, where the information is stored, and what the actual danger is to mobile-user privacy and security. Location identification is not a "Big Brother" attempt to invade the privacy of mobile subscribers; it is driven by the need to defend citizens and property against the increasing terrorist threat. The tension between maintaining one's privacy while maximizing the usefulness of the Internet is not inherent to mobile location. Anytime someone conducts a Web search, posts updates on a social media site, or posts comments on a blog, that information could be monitored and used. If people want to prevent this or remain anonymous, they would need to take some extreme and impractical measures (e.g., stop using a cell phone, tablet, Internet at home or at work, and stop using social-media sites).