Sep 28 2017 Can’t Find A 911 Caller? NG911 Mapping To The Rescue


Lately, we have been hearing more and more reports of the challenges of locating 911 callers. With the significant advancements in technology, it’s time for PSAPs to make the jump to Next Generation 911 sooner rather than later to address this serious problem. Even the FCC Chairman agreed in his recent testimony in front of Congress that moving off of antiquated emergency services technology is critical for public safety.

But as urgent and necessary as this transition is, we also know first-hand that undertaking a migration to NG911 is not without its own set of significant challenges. And, upgrading your mapping system is just one of the critical steps to making that transition.

How Mapping Currently Works

Before you can understand how to upgrade your mapping system, you need to understand why a mapping system upgrade needs to occur in the first place.

In most PSAPs today, mapping is used to graphically display the location of a landline caller on a map. This is accomplished by using the street address of the caller retrieved from an Automatic Location Identification (ALI) database. This information is stored in the Master Street Address Guide (MSAG), a primary repository for street names and house numbers in a community that are identified by a telephone number. The MSAG is also used for call routing and identifying the closest assigned emergency responders to the address.

With the increased use of wireless and VoIP devices over the past decade, the longitude and latitude (LAT/LONG) of the caller’s location – or the LAT/LONG of the closest cell tower to the caller – is also used to display a location on a map. Since there is no street address, a common map is needed by the PSAP, the dispatchers, and the first responders.

Challenges with Current Location Services

Here’s where things get challenging.

Currently, most PSAPs utilize technology that is optimized for landline phones. This is problematic, as over 70 percent of 911 callers are doing so with a mobile phone. And, the Enhanced 911 Wireless Services that are in place to pinpoint callers on those devices are inconsistent.

The Emergency Location Services for wireless callers is available as Phase 1 wireless and Phase 2 wireless.

Phase 1 Wireless provides a location based on the closest tower with the direction of the caller, based on the face of the tower receiving their signal. Unfortunately, this is typically used in remote areas, where cell towers are few and far between, and when callers don’t have GPS capabilities on their phone.

Phase 2 Wireless provides the location of a caller based on cell tower triangulation or GPS coordinates. But in order for the triangulation to work accurately, there must be at least three cell towers present. And even then, the location is really only accurate down to an area about three-quarters of a mile.

Fundamentally, 911 call center operators require a caller’s phone number and location in order to dispatch the right response team. And with the present infrastructure in place, that is very difficult when handling callers on wireless or VoIP devices – they’re mobile and often don’t have a fixed location.

What’s more, many of these callers don’t realize the location being provided to the system is often inaccurate. This is especially true if the caller happens to be indoors, which is often the case – as accurate as GPS is, it doesn’t work well under someone’s roof due to interference with the satellite signals needed to determine a caller’s location.

Fortunately, there are already advances planned to address these limitations. Google and other providers are making strides in providing more accurate location data in emergency situations by ensuring smartphones are able to provide accurate location information, indoors and outdoors.

Improved Mapping for PSAPs with Next Generation 911

Once location accuracy is solved, the next critical improvement is for PSAPs to implement mapping systems that can assist in call routing, and deliver the location information in a manner that it can be easily shared with dispatchers and first responders. In order to understand how NG911 mapping works, we need to familiarize ourselves with two key NG911 functional elements:

  • Geographical Information System (GIS)
    A system of hardware and software for storing, retrieving, mapping and analyzing geographic data.
  • Spatial Information Function (SIF)
    A specialized form of a GIS that is used to support the Emergency Call Routing Function (ECRF) and Location Validation Function (LVF), key functional elements of the ESInet to route emergency calls.
Take the Next Step Toward Better Mapping with GIS Data

For PSAPs migrating to Next Generation 911, there needs to be a realization that their GIS data will be a vital component of their future solution. Not only will PSAPs need to assess their GIS readiness for replacing MSAG for call routing and caller location, they will also need to prepare the GIS data for its new role for NG911 communications, and maintain and update that data within their new NG911 system.

GIS systems are going to serve an increasingly important role in the reliability and accuracy of emergency services in North America. But, it is unrealistic to assume the Federal Government will be able to make the changes necessary for NG911 to become a reality. PSAPs across the country will need to make the investment of time and money to migrate to NG911 and one of the key steps is to update the mapping infrastructure.

Fundamentally, it comes down to improving our ability to save lives and protecting the communities emergency services teams and responders.