Mobile 9-1-1 Calls Explained

Every day we use our cellphones and wireless technologies during emergencies. For more than 20 years, the wireless industry partnered with the public safety community to ensure that 9-1-1 services work when we need it most. Today, most people call 9-1-1 from their cellphones because wireless services are convenient, mobile, and reliable.
Through constant innovation in network and handset technologies, the wireless industry has continued to enhance the 9-1-1 services and tools on your cell phone, including location information and text messages. 9-1-1 calls from wireless handsets rely on location services developed specifically for 9-1-1, similar to the Location Based Services (LBS) used for commercial applications. In addition, 9-1-1 calls centers are increasingly accepting text messages sent to 9-1-1 from cellphones.

Even with these enhancements, there are a few important points to remember about wireless 9-1-1 communications:

  • Know your location. Even if your mobile phone has enhanced location features, 9-1-1 call takers will ask for your location to help them direct first responders to your emergency as quickly as possible.                
  • Call if you can, text if you can’t. A voice call to 9-1-1 is the preferred method for most 9-1-1 professionals, but many 9-1-1 call centers accept text messages if you can’t talk.

You may only have to contact 9-1-1 once, but you can be better prepared for an emergency by understanding how your cellphone can help by learning more from our FAQs below. You can also find more information about wireless 9-1-1 by visiting the Federal Communications Commission’s website.

​Wireless 9-1-1 Calls FAQ

How do wireless 9-1-1 calls work?

When you dial 9-1-1 on your cellphone, your call will be automatically sent to a 9-1-1 call center to begin responding to your emergency. During the 9-1-1 call, your cellphone will automatically work with the wireless network to determine your location and then deliver that information to a 9-1-1 call center. While your wireless phone is working to determine the location, a 9-1-1 center professional will ask “where is your emergency?” You should try to provide as much detail about the emergency and your location (e.g., address, floor/suite/apartment number, etc.) to the call taker. The 9-1-1 professional provides this location information to the responding local fire, police, ambulance or other emergency service providers.

How does Text-to-911 work?

Your wireless carrier can deliver SMS messages to 9-1-1 if the 9-1-1 call center in your area is upgraded to receive these kinds of messages. If the 9-1-1 call center in your area does not accept SMS text messages, your wireless provider will instruct you to dial 9-1-1 instead.

Remember that text-to-911 only works with your carrier’s SMS services (and not MMS, e-mail or apps) and may not support location information. Text-to-911 is an important option if you can’t speak during an emergency and/or if you are deaf, hard of hearing or speech impaired.

How does wireless 9-1-1 location work?

Location information delivered with a wireless 9-1-1 call is a carefully constructed and balanced process developed between wireless providers and 9-1-1 professionals through its more than 20 year partnership. Wireless calls to 9-1-1 go through a two-phase process per the FCC’s rules. During phase 1, your wireless call is routed to a 9-1-1 call center (known as a Public Safety Answering Point (PSAP)) determined by the location of the cell tower handling the call. Next, during phase 2, the 9-1-1 call center requests more specific location information and the wireless network uses a combination of network and handset based technologies, including GPS-satellite information, to send coordinates estimated within a range of 150 to 300 meters. The 9-1-1 call center uses the estimated coordinates to direct local first responders to your emergency location.

Today’s wireless E-911 location technologies were designed exclusively for 9-1-1 use when most wireless calls to 9-1-1 were placed outdoors. Over 90 percent of wireless calls to 9-1-1 are delivered to call centers with this type of location information. With almost 50 percent of American households wireless-only and the majority of calls to 9-1-1 coming from wireless networks, wireless carriers are working with the FCC and 9-1-1 professionals to quickly enable a new approach to wireless 9-1-1 location information.

In 2017, the wireless industry will begin harnessing commercial location based service (LBS) technologies used by Americans every day, including Wi-Fi® Access Points and Bluetooth beacons, to improve 9-1-1 location information for wireless 9-1-1 calls made indoors. Improvements to wireless 9-1-1 location accuracy both outdoors and indoors will also come from innovative satellite (e.g., GPS) and network based technologies. In 2021, at least 80 percent of all wireless 9-1-1 calls will use this technology to deliver to a 9-1-1 call center a location estimate within 50 meters or a “dispatchable” location.

Are the wireless 9-1-1 location information technologies used today the same as the location-based service (LBS) technology we use in apps?

Until very recently, 9-1-1 location technologies used by wireless carriers were designed exclusively for 9‑1‑1 purposes and before all of the commercial LBS services that Americans use today were widely available. These 9-1-1 location technologies work well in outdoor spaces, but they don’t have the same capabilities that the LBS technologies we use today (both outdoors and indoors). The commercial LBS that we use on our cellphones for maps, directions and photo tagging have been extremely successful and reset everyone’s expectations about the potential for location information. In 2015, the FCC established new rules that will enable the wireless providers to use the same LBS technologies we know today, but with added authentication and features for 9-1-1, such as vertical information, including floor or room number.

What is “dispatchable” location? What is the National Emergency Address Database (NEAD)?

“Dispatchable” location, identified by the public safety community as the “gold standard” in location information, means a street address plus the floor, suite or apartment number. This location is the preferred location information for the public safety community to provide emergency services to the caller.  Dispatchable location is different than the estimated longitude and latitude coordinates that are generated for all wireless calls to 9-1-1. A disptachable location may soon be available where a wireless provider can determine if a Wi-Fi® Access Point or Bluetooth beacon is associated with a street address.

CTIA is leading an effort to develop a National Emergency Address Database (NEAD) of Wi-Fi® Access Point and Bluetooth beacon technologies that will enable wireless carriers to deliver a dispatchable location to the 9-1-1 call center. Ultimately, a dispatchable location will provide 9-1-1 call centers and first responders with information to more quickly respond to emergencies.

How will new location technologies improve wireless 9-1-1?

The wireless industry is taking an “all of the above” approach to improving 9-1-1 location accuracy. Today, wireless 9-1-1 location information is determined through a combination of wireless network and GPS-based technologies. Within the next few years, new chipsets in our cellphones will be able to calculate more granular location information for a 9-1-1 emergency communication by seeing more satellite technologies (i.e. AGNSS). By investing billions of dollars to continue leading the world in mobile wireless services, U.S. wireless carriers will also deploy technologies that will improve the ability of a wireless network to pinpoint cellphones outdoors and indoors for 9-1-1 emergency communications. To support dispatchable location solutions, CTIA will be working to build a database of millions of Wi-Fi® Access Points and Bluetooth beacons that are already available.

CTIA and our member companies are also eager to evaluate innovative beacon, barometric pressure sensor and radio frequency identification technologies that might one-day help to further enhance 9-1-1 location information. These evaluations will be conducted through an independently administered and transparent 9-1-1 Location Technologies Test Bed.

Last Updated: February 2016
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