A Decade of Technology Improvements in 9-1-1 Location Accuracy Helps First Responders Save Lives

April is Emergency Communications Month, created by the U.S. Cybersecurity and Infrastructure Security Agency (CISA) to celebrate the vital role emergency communications play in supporting America's first responders. Cellphones have changed the landscape of emergency communications, providing lifesaving help for millions of Americans when they are at home, work, or on the go.

Amber is one of millions of Americans whose cellphone helped save their life. She recalls driving home one night when she was sideswiped by another driver, whose vehicle flipped onto hers and left her pinned. Although she managed to dial 9-1-1, Amber was too disoriented to determine her precise location-or even which highway she was on-to relay that information to the operator. Yet, first responders were able to reach Amber in minutes thanks to wireless location data provided by network operators.

For more than a decade, the wireless industry has worked closely with smartphone providers, technology companies, and public safety groups, including APCO International and NENA The 911 Association, working together to enhance the technology used to locate wireless 9-1-1 callers like Amber. This has led to improvements in wireless location accuracy across every metric-horizontal, vertical, outdoor, and indoor-helping millions of people who need to be found in an emergency. Today, 9-1-1 operators can locate you nearly anywhere-from the side of a highway to the inside of a high-rise-all thanks to a decade of innovation in wireless location accuracy technologies.

This innovation enables a wireless provider to give a 9-1-1 operating center, called an Emergency Call Center (ECC), an estimated location for a 9-1-1 caller. The 9-1-1 operator then combines the wireless caller's estimated location with their own mapping software (GIS) to send a first responder, like police, fire, or EMS, to the appropriate location when the caller cannot identify his/her calling location.

Today, 9-1-1 operators can locate you nearly anywhere-from the side of a highway to the inside of a high-rise-all thanks to a decade of innovation in wireless location accuracy technologiesTom Sawanobori, Senior Vice President & Chief Technology Officer, CTIA

Early Innovations: GPS and Cell Towers Home in on Location

The wireless industry began its work to enhance 9-1-1 location accuracy through the use of network-based location techniques to estimate the location of a caller. These techniques are still part of the location provision process today: when you place a 9-1-1 call, your phone pings the nearest cell tower, and this information can be used to triangulate an estimated location between cell sites, which is shared with the 9-1-1 operator.

The next key innovation enabled mobile device manufacturers to add Global Positioning System (GPS) receivers into their handsets. If the phones can "see" GPS satellites, this feature can provide a very precise location and augment the network-based triangulation estimate. Today, virtually all smartphones and feature phones in the United States are equipped with GPS receivers and other sensors.

These improvements transformed the industry's ability to provide reliable latitude and longitude location data to first responders, particularly for outdoor locations.

Device-Based Solutions Further Enhance Indoor Location Accuracy

Working with public safety officials and policymakers, the wireless industry continued to invest in enhanced solutions to address indoor accuracy, both in the horizontal and vertical dimensions. With expertise from top engineers, the industry worked to develop state-of-the-art device-based hybrid technologies, which were tested starting in 2015 and have now been deployed for several years. This tool has proven to be a key tool for locating in-building callers in particular.

Device-Based Hybrid solutions use a combination of technologies and sensors-including satellite GPS, crowd-sourced Wi-Fi measurements, and other sensor information-along with wireless providers' other 9-1-1 network and device information, to produce a higher-accuracy location. This is the same technology used for ridesharing and navigation apps. Device providers launched these capabilities within software updates to existing devices, leveraging the technological capabilities of recent models.

Over 99% of active Android devices can leverage a device-based hybrid solution called Emergency Location Service (ELS) to provide a more accurate location using a variety of sensors in the device. Available on the vast majority of iPhones, Apple' device-based hybrid solution is called Hybridized Emergency Location (HELO). HELO fuses information from device sensors, including GPS and Wi-Fi, to provide an estimate of the 9-1-1 caller's location.

Today, over 80% of 9-1-1 calls are being located by device-based hybrid technologies-a remarkable accomplishment in under ten years-to pinpoint callers inside buildings with increasing accuracy.

With around 80% of approximately 240 million 9-1-1 calls made via wireless, the industry is able to locate callers quickly and more accurately.Tom Sawanobori, Senior Vice President & Chief Technology Officer, CTIA

Using DBH to Resolve Vertical Location and Other Challenges

The next challenge the wireless industry tackled was estimating the 9-1-1 caller's vertical location, which is especially important if the caller is in a multi-story building. Device-based hybrid technologies also help in this regard, providing estimated location information in the form of a latitude, longitude, and elevation to the 9-1-1 operator. And two years ago, the wireless industry reached a major milestone with this technology: providers can now locate a wireless 9-1-1 caller within ± 3 meters-or within 1 floor of a multi-story building-for at least 80% of wireless 9-1-1 calls, also meeting FCC standards.

Today, providers are leveraging DBH technologies to deliver benefits in other ways, ensuring wireless 9-1-1 callers get directed to the right emergency call center. In a small percentage of cases, 9-1-1 calls are routed to call centers that serve areas other than where the caller is (such as in a different county or across a river), because the calls are routed based on the cell tower location rather than the device's actual location. Wireless providers and ECCs have begun to use DBH solutions to route calls based on the location of the device. This technique, known as location-based routing, is expected to help decrease the rate of misdirected 9-1-1 calls, saving more lives.

The newest innovations in the vertical location accuracy arsenal are barometric pressure sensors. Increasingly available in the latest smartphones, their precise measurements may enable even more accurate height estimates, which when combined with DBH solutions and any information the 9-1-1 operator has about the building, are especially helpful for locating 9-1-1 callers who could be on any floor. As 9-1-1 call centers continue to update their technology to accept vertical locations, providing a height estimate can help 9-1-1 call centers dispatch first responders more accurately, who in turn can respond to a caller in need more quickly. To continue to improve these vertical estimates, the industry is examining new and innovative ways to leverage new technologies and capabilities.

Appreciating Those Who Serve

As we recognize the wireless industry's 9-1-1 location accuracy accomplishments in honor of Emergency Communications Month, we also celebrate National Public Safety Telecommunicators Week, honoring the telecommunications personnel in the public safety community who field millions of emergency calls every year. These skilled telecommunications are a vital part of the public safety workforce and should be reclassified and appropriately recognized for their life-saving contributions to our communities. We're proud to support these personnel through our work with ECCs-and we look forward to continuing our work with them to ensure the latest location accuracy technology is implemented into their systems.

With around 80% of approximately 240 million 9-1-1 calls made via wireless every year, the industry knows what an important lifeline a mobile phone is in an emergency. This knowledge fuels our ongoing research and development into location-accuracy technologies and advocacy.

With our public safety partners, the wireless industry is-and will remain-committed to constantly improving our nation's 9-1-1 system so help can find you as quickly and accurately as possible.