From GPS to IPS: A new approach to locating people inside buildings

Dec. 15, 2014
Ability to pinpoint the exact location of individuals during emergencies could revolutionize security operations

A dozen years ago, not many individuals outside of the military had ever heard of global positioning system (GPS) technology. Today, it’s in virtually every new car and smartphone, and many people depend on it as a basic necessity. GPS has transformed many aspects of our culture simply by enabling people to locate themselves on a map - unless they are inside a building.

The truth is GPS technology is largely incapable of precisely pinpointing locations inside buildings. Interference from Wi-Fi and other electromagnetic systems as well as concrete walls, steel infrastructure and other structural elements block signals and make it difficult, if not impossible, for the technology to determine exactly what room a person is in, or even what floor they are on.

For the typical wayfinding and commercial applications burgeoning within the GPS field, this is beginning to pose a problem. For example, retailers in a mall would greatly benefit from location services for a wide variety of sales-related activities. A number of technology-based solutions incorporating Wi-Fi, beacons and RFID are currently in development for these applications, driven by a variety of business needs to improve profitability.

In the world of risk mitigation, the need is much more immediate and critical. For the security industry, true indoor positioning systems (IPS) capable of pinpointing the location of individuals inside buildings have the potential to transform security operations during and after an incident.

During an active shooter situation, tornado, fire or other emergency event, security personnel need to know how many people are affected and exactly where they are located. Simply knowing there are many shoppers in a mall or travelers in an airport isn’t enough; in an emergency, real-time information on precisely where in the building each individual is situated can make a life-or-death difference. Adding an element of communication significantly improves the efficacy of the solution, such as enabling individuals in an office building to inform law enforcement officials of where a shooter is located inside a building, along with other critical details of the unfolding situation. If the communication is bi-directional, more risk can be eliminated as people can be guided or directed through safe passageways to reach shelter or to exit the facility. In a situation such as a chemical spill when the facility needs to be vacated, there is a huge value in knowing if anyone is still inside the building, who and where they are, and who has safely evacuated, along with the ability to help those who need guidance in finding a safe way out.

The growth of GPS for helping travelers find their way, along with limited indoor location services used for commercial applications, has made the need for accurate indoor positioning systems even more clear. In the past, providers have tried to address this by patching together solutions leveraging GPS, RFID and other technologies; yet none have been capable of precisely, reliably and affordably pinpointing individuals down to specific room and floor. That is finally changing. Newly developed IPS technologies that leverage the ubiquity of smartphones are quickly transforming the landscape and providing a way not only to locate, but also to communicate with individuals inside a building during a security incident.

The most accurate indoor positioning systems today often utilize a blend of technologies to ensure the highest levels of precision, broadest range of device support and affordability. Today’s IPS technologies include Wi-Fi, Bluetooth 4.0, distributed antenna systems (DAS), LED lighting that emits modulated light specific to an indoor location, magnetic field energy readings from the Earth and embedded sensors in mobile devices. While a number of these approaches are still far from market commercialization, Wi-Fi and Bluetooth Low Energy (BLE) beacons form the basis of the current and most common IPS technologies.

Wi-Fi and BLE beacons can be used either independently or combined to create an indoor location map using a variety of methods including triangulation, signal fingerprinting and direct association. All three of these methods depend on individuals carrying smartphones, which makes sense in today’s society, where over 70 percent of all emergency calls come from mobile phones.

Triangulation, commonly understood in context of cellular towers and GPS to determine location, estimates the relative distance between an individual and at least three radio devices such as Wi-Fi access points or BLE beacons with known locations. Since walls and other objects can interfere with signal strength, this method has significant limitations indoors.

IPS fingerprinting overcomes the interference problems of triangulation. Installing an IPS fingerprinting-based system within a building is a relatively straightforward process. It requires capturing Wi-Fi and/or beacon radio signals from a smartphone in each of the desired locations within a building. Each individual collection (or sampling) of radio signals in a specific room on a specific floor is classified as a “fingerprint.” Once setup, mobile applications can query this IPS infrastructure and the system will have the intelligence to report that mobile user’s location to security.

A third method, direct association, works differently for Bluetooth beacons and Wi-Fi access points. Bluetooth beacons carry unique identifiers; working through an app on a mobile device that captures this identifier, the IPS can pinpoint the location of the device. Wi-Fi networks can be deployed in a number of ways, but most commonly consist of a set of access points, each of which has a unique address that can be identified by a Basic Service Set Identifier (BSSID). The IPS can calculate signal strength between any access point (with a known location) and mobile device to determine the mobile device’s location; however, when used alone this method has lacked the precision of other IPS methods.

For the incidents that are occurring with growing frequency in shopping malls, office buildings, schools and even government facilities, hybrid IPS technologies combining Wi-Fi and beacons offer the best methodology available to protect individuals, reduce injuries and prevent loss of life.

Hybrid IPS technologies offer the most flexibility in design, better accuracy and a lower total cost of ownership – all of which are great advantages to organizations that have limited security budgets, yet have a strong need to provide a safer environment to customers, personnel and visitors. Beyond that, by leveraging technology that may already be in place, such as existing Wi-Fi networks or beacons in retail environments, they are faster to implement and easier to integrate with existing security protocols and systems. Finally, it makes sense to capitalize on the pervasiveness of mobile devices to build a better way to keep people safer wherever they are – inside or out.

About the Author

Josh Sookman | Founder and Vice President of Business Development, Guardly

Josh Sookman is the founder and vice president of business development at Guardly