Giving Law Enforcement a Head Start With Radio-Frequency Technology

Most United States law enforcement agencies have been discouraged by the low accuracy, lack of timeliness and poor reliability of information delivered by traditional wireless location technologies. They also aren't equipped to put state-of-the-art capabilities to work in fighting crime.

Radio frequency “pattern-matching” technology provides critical breakthroughs. Radio frequency has been enhanced and proven in deployments for E911 emergency services in the United States and for lawful location interception in other parts of the world. The software-based wireless location technology provides real-time, high-accuracy capabilities that can give an agency a dramatic head start in an investigation.

There, Right Now

There are numerous ways that wireless location capabilities could be brought into play in law enforcement investigations. The issue is that traditional geolocation technologies aren’t powerful enough for law enforcement’s needs. Most conventional systems can place the location of a mobile device user to within a radius of 300 to 500 meters (roughly 900 to 1,600 feet). But in many cases, it’s not enough to know which individuals might have been in the neighborhood at a certain time period of a criminal event; law enforcement personnel need to know who is there right now.

Law enforcement agencies’ reliance on wireless-location solutions is typically low. They know they can, for example, subpoena wireless operators for location data on a stolen mobile device. But in practice, agencies are not overly interested because the data this yields are neither timely nor precise enough to sufficiently enhance investigations. How valuable is it, for example, to learn that a missing mobile device was within 500 meters of the intersection of Fourth and Main streets an hour and a half ago?

The technologies underlying conventional wireless locations are ill suited for investigative purposes. Vague accuracy is the downfall for Cell Identification/Enhanced Cell Identification technologies since they depend on cell tower location, distance from tower (timing advance) and in some cases signal strengths. In dense, urban areas and indoors, technologies like Assisted GPS perform poorly since they depend on line-of-sight with at least three satellites.

Also, GPS can be disabled, jammed or spoofed. Uplink Time Difference of Arrival (U-TDOA) requires complex-to-negotiate, expensive deployment of radio hardware on all operators’ cell towers for triangulating uplink signals. The U-TDOA performance is also driven by line-of-sight conditions and hence limited in dense, urban and indoor environments. Wi-Fi is typically not available on most user handsets and if available, can be easily disabled. Also, Wi-Fi-based location does not provide the consistency, reliability or accuracy required, especially in deep indoor environments. None of the technologies consistently deliver the array of benefits necessary to enhance their investigations, and so agencies historically have passed on significant usage.

Where and When, Precisely

Software solutions based on radio frequency pattern matching deliver key innovations, enabling agencies to more quickly and accurately locate any and all users regardless of their environments — at the current moment or for a period of time in the past.

Here’s how it works: The technology defines a mobile device’s unique location “signature” — data such as signal strength, time delays and other parameters that are available through a wireless network. The signature is comparable to a fingerprint’s unique set of lines and swirls. This information is automatically studied against a database of predicted values, dependably yielding in real time the device’s location to a radius of 50 meters or better; even in dense urban and indoor environments where a lack of line of sight impedes other technologies. The precision of the location signature is enhanced by shadowing of walls and buildings in the settings where other technologies are hampered.

In addition to delivering the most precise locations, radio frequency pattern matching is unmatched among wireless location technologies in a variety of other ways:

• It can locate all users in bulk, on a near real-time basis, enabling applications such as mass location interception that are extremely valuable to law enforcement agencies in, for example, assembling witness lists.
• Because pattern matching is software-based, it allows agencies to rapidly augment their investigations with highly accurate mobile-device location without the delays and costs of network hardware. Also, this makes it a cost-efficient, long-term technology that averts costly equipment upgrades or replacements.
• Pattern matching operates without regard to subscriber setting of services (Wi-Fi on/off, GPS on/off, etc.).
• Finally, pattern-matching software can ubiquitously locate devices — from the smartest of the smart devices to the dumbest of the dumb handsets — to within a narrow zone of interest for law enforcement agencies.

Transforming Investigations

Radio frequency pattern-matching software avails real-time, high-accuracy location capabilities to any investigator on the agency network. And the impact on investigations is transformative — as firmly established by agencies around the world.

A police agency, for example, could acquire a list of 15 or 20 mobile devices within 30 to 40 feet of a vehicle at the moment it was parked in advance of a criminal event, enabling officers to more quickly assemble a tight list of interviews to pursue. Chances are very good, in fact, that one of the users would be the perpetrator. If nothing else, however, it puts police officers in touch with the precise people they want to talk with about what they saw.

Post-event analytics also can help agencies see, for example, whether a suspect might’ve been visiting known venues of suspicion more frequently in the weeks leading up to an event. Another example is, if the police immediately suspect five individuals when a crime occurs, an officer could track in real time on a computer screen where those individuals’ mobile devices are. If all the devices are discovered to be near their users’ homes or workplaces, except for one that’s heading to the airport, suddenly police have actionable information.

Ultimately radio frequency pattern-matching wireless location solutions enable law enforcement to more quickly and wisely deploy resources. They give law enforcement a more advantageous jumping-off place for investigations — a head start.

Shrinking the Pinpoint

The precision of radio frequency pattern-matching technologies figures to grow finer as future mobile devices are laden with more capabilities and sensors and as wireless network coverage becomes denser. Accuracy to within 10 meters on a consistent basis is on the horizon. Another area for future development is 3-D location capability, so that agencies could even surmise the mobile devices present on the floor of a building at a particular address.

Radio frequency pattern-matching wireless location technologies enable law enforcement agencies to more intelligently and effectively target efforts, shrink the pinpoints on suspects and shorten successful investigations.

Kevin Lindsey is the director of business development for Polaris Wireless.