Celebrating the 50th Anniversary of the First 911 Call

Why “Where” Matters for NextGen 911

February 16, 2018

The 50th anniversary of the first 911 call, made on February 16, 1968, in Haleyville, Alabama, has arrived. In 1968, it would be difficult to imagine that an estimated 240 million 911 calls would be made annually, 80% of them from cellular devices. With the increasing number of calls from mobile phones, there is concern that 911 has not kept pace with advancing technology. The question that inevitably gets asked is, “Uber and Facebook know my location, why doesn’t 911?” When seconds count in life and death situations, concern from the public is understandable. Today, 911 is on the verge of a much-needed upgrade, and geographic information is a critical component.

NextGen 911 promises to enhance the system with new capabilities like sending text and video to 911. While these are exciting, the most critical of these new capabilities is the use of local geographical data to accurately locate callers. A Federal Communications Commission (FCC) report titled Wireless E911 Location Accuracy Requirements states that “location accuracy improvements we proposed could save approximately 10,120 lives annually.” The role GIS plays in NextGen 911 cannot be understated. Without accurate GIS data, NextGen 911 will not succeed.

Understanding 911

To understand the role of GIS in NextGen 911, it is important to understand how the current system, Enhanced 911, or E911 works. 911 as a system has three functions: 1) call routing; 2) call taking; and 3) dispatch. Call routing is the process of verifying the caller’s location and sending the caller to the correct Public Safety Answering Point (PSAP) or 911 Center. This worked well when people made 911 calls from land lines that had a fixed address. With a land line, your billing address is stored in text databases called the Master Street Address Guide (MSAG) and Automatic Number Information / Automatic Location Information (ANI/ALI), and your location can be verified easily. If you are using a cellular device, current 911 technology triangulates your GPS location from a cell tower which can place the call up to a quarter mile away from your actual location. An error could result by placing the caller in a different town, county, or state, thereby transferring the emergency to the wrong PSAP and delaying the response. An example of this occurred in Cherokee County, Georgia. Shanell Anderson drove her car into a retaining pond and was able to tell 911 where she was located. The problem was that she was in Fulton County, and the cell tower she connected to was in Cherokee County. The call taker could not process the address because the data stopped at the county line. It took nearly 20 minutes for units to arrive, but it was too late. NextGen 911 will help to prevent deaths like Shanell’s.

Call taking and dispatch is the process of gathering the pertinent information in order to send the correct agency and resources to the emergency. “Where?” is one of the most important questions in the initial seconds of the call. Call takers and dispatchers are required to ask, “Where is the location of your emergency?” This question is necessary, because call routing cannot be relied on to give an exact location of the caller. Call-takers and dispatchers rely on the data loaded into a Computer Aided Dispatch (CAD) system to determine who to send to the call. If the data is correct, the process is quick, but too often call-takers and dispatchers face difficulties in processing the call. This happens because callers are not familiar with their location or the caller may use nearby businesses such as a Starbucks or McDonald’s to identify their location. Many 911 centers do not have these businesses or common names populated in the CAD. For example, a call center receives a call for a vehicle accident in front of a Dunkin Donuts. The caller says that the emergency is in front of the Dunkin Donuts where Main Street exits at Chestnut Street. The call taker uses the information given by the caller that can be processed in the system: Main Street and Chestnut Street. However, the intersection of Main and Chestnut is six blocks north of the Dunkin Donuts, and the delay in response could have serious consequences. If the emergency responders are familiar with the area, they can help correct the location, but this is real issue that happens daily. This situation can be avoided with accurate and up-to-date GIS data. It is imperative that location data in a 911 call center must be accurate.

The Role of GIS in NextGen 911

In NextGen 911, GIS is critical. GIS data replaces the MSAG and works with the legacy ANI/ALI data. This data will all reside in what is called the Emergency Services IP Network (ESinet). The Location Validation Function (LVF) is the part the ESinet where GIS data will reside and provide the accurate location from the wireless carrier. The LVF will determine where the call is located and to which PSAP to direct the caller. Within the PSAP, the same GIS data will be used to access the location information and will be loaded into the CAD system. Instead of asking the emergency location, call-takers will be able to ask, “Is your emergency located at x?” If the location is correct, time will be saved in the process and call-takers and dispatchers can focus on gathering information that will aid the responders. If the caller cannot verify this information, call takers and dispatchers can use the same methods deployed today—basing the location on the caller’s description of the location of the emergency.

Now and Future

NextGen 911 has minimum GIS data requirements. The requirements are street centerlines, PSAP boundaries, and Emergency Service Zone boundaries. The National Emergency Number Association (NENA) has determined that more data layers should be required, and they have released a GIS data model for public review. One of the layers that NENA requires for NextGen 911 is address points. They require unit level addressing and recommend collecting elevation or height information. Why is height important? If a caller is located on a college campus, office building, or apartment complex, then 911 will be able to determine in which room, floor, or unit the caller is located. Common Place Name (CPN) is also part of the address point layer and is the most requested information from call takers and dispatchers because callers unfamiliar with an area will use landmarks to identify the location of an emergency. Collecting and maintaining data for 911 will take a tremendous effort but will reduce 911 emergency response time and save lives.

Everybody Wins

With these improvements to 911, everybody wins. The public will finally get a 911 system that is optimized to locate a caller and expedite the response. Call takers’ and dispatchers’ jobs will become more efficient with accurate location information and should improve emergency response time. Responders will arrive on location faster, and, if the FCC report is correct, save more lives and make a positive difference in their communities. Other users of the street centerline and address point layers will benefit as well, including public works departments, planning, permitting, housing, and health departments. The stakeholders involved in creation, maintenance, and use of GIS data will need to collaborate to realize the potential benefits of an enhanced street centerline and address point data layers.

When people are having the worst day of their lives, help is only three digits away. As the 50th anniversary comes and goes, the promise that NextGen 911 brings is exciting. Improvements will be seen not only in the 911 system and in public safety, but across all local government departments that rely on this data to facilitate their business processes. When seconds count, accurate location information will optimize 911, protect property, and most importantly, save lives.


Contributed by: Peter Hanna, GIS Specialist at JMT Technology Group