Print
Share page with AddThis

Enhanced 911 & Cell Phones

TYPES OF 911

Basic 9-1-1: Basic 9-1-1 means that when the three-digit number is dialed, a call taker/dispatcher in the local public safety answering point (PSAP), or 9-1-1 call center, answers the call. The emergency and its location are communicated by voice (or TTY) between the caller and the call taker.

Enhanced 9-1-1: In areas serviced by enhanced 9-1-1, the call is selectively routed to the proper PSAP for the caller’s location, and the PSAP has equipment and database information that display the caller's phone number and address to the call taker. 93% of counties with 9-1-1 coverage have enhanced 9-1-1 for callers. The term “enhanced 9-1-1” is not synonymous with wireless 9-1-1.

Wireless Phase I: When Phase I has been implemented, the call taker automatically receives the wireless phone number. This is important in the event the wireless phone call is dropped, and may allow PSAP employees to work with the wireless company to identify the wireless subscriber. Phase I also delivers the location of the cell tower handling the call. The call is routed to a PSAP based on cell site/sector information.

Wireless Phase II: Phase II allows call takers to receive both the caller's wireless phone number and their location information. The call is routed to a PSAP either based on cell site/sector information or on caller location information.

9-1-1 Calls through VoIP: Business and residential use of Voice over Internet Protocol (VoIP) telecommunications services is growing at a rapid pace. Methods to bring 9-1-1 calls into E9-1-1 systems have recently become available, and NENA is leading work to develop full E9-1-1 capability for VoIP-based services.

Next Generation Trends: There are currently at least 8 million customers who rely on wireless as their primary service (having given up wireline service or chosen not to use it).

The number of 911 calls placed by people using cell phones has more than doubled since 1995, to over 50 million a year. The number of cell 911 calls the Marion County Emergency Communications Center receives daily is running between 50 and 70 per cent of the 911 call total. For many citizens, the ability to call 911 for help in an emergency is one of the main reasons they own a cell phone. Other wireless 911 calls come from citizens reporting traffic accidents, crimes or other emergencies.

LOCATION, LOCATION, LOCATION

People make more 911 calls from cell phones than landlines these days. Contrary to what is seen on television crime shows, the accuracy of the technology that guides rescuers to cell phone caller can range from a few yards to several miles, even though federal law requires cell phone providers to guarantee that their callers can be located in emergencies.

Unlike landline telephones at houses or businesses, when a 911 call comes in to a 911 Center from a cell phone, the operator often only has a vague idea of where that person in distress is calling from. Callers who are lost or incapacitated and cannot speak may wait for hours while rescue workers try and track their location.

CTIA, the nation's top wireless industry lobbiest group, reports that 230,000 911 calls are made from cell phones each day. The group also estimates that 8.4 percent of households are "wireless only.

"People have to recognize that it is not the wireline 911 system and never will be because you can only bend the laws of physics so much."  CITA spokesman Joe Farren.

The location challenges stem from inherent limitations on how cell phones work and a decision the FCC made several years ago to allow manufacturers to use two different location technologies:

Network Technology - uses cell phone towers to zero in on a caller through a processs known as triangulation. To triangulate there has to be at least three towers near the caller, which is unlikely in rural areas.  The towers can be existing cell-phone towers, water tanks, tall buildings or other locations where receiving antennas can be mounted. Used the known speed of radio signals, the distance from receivers can be calculated. Federal law and FCC rules require that providers using the network method should be accurate to within 300 meters, about three footballs fields, for 95 percent of calls and within 100 meters for 67 percent of calls.

GPS Method - uses satellite technology embedded in the phone.  A chip embedded in the wireless phone receives signals from three or more satellites and calculates the location. Responders must be guided to within 150 meters for 95 percent of the calls and 50 meters for 67 percent of the calls.

While cell phones are an important public safety tool, they also create challenges for public safety and emergency response personnel. Assume the 911 operator does NOT know the caller's location. Even if the cell phone is able to provide location information, the chances are the caller will need to provide the 911 operator with additional location information. The approximate location the 911 Center receives could be as large as three football fields. Be prepared to give specific location information to the 911 operator. It is important to remember that wireless locations are NOT as accurate as wireline locations.

A wireless phone is actually a radio with a transmitter and a receiver that uses radio frequencies, instead of telephone wire, to connect callers. They are not associated with one fixed location or address. A caller using a cell phone could be calling from anywhere. While the location of the cell tower used to carry a 911 call may provide a general location of the caller, that information is not normally specific enough for rescue personnel to deliver assistance to the caller quickly.

In addition to other efforts to promote coordinated emergency services, the FCC has adopted wireless 911 rules. These rules are aimed at improving the reliability of wireless 911 services and identifying the location of wireless 911 callers to enable emergency response personnel to provide assistance to them much more quickly.

The FCC’s Phase II E911 rules: 

  • Requires wireless carriers, within six months of a valid request by a PSAP (Emergency Communications Center), to begin providing more precise location information, specifically, the latitude and longitude of the caller. The new equipment in place in the Marion County Emergency Communications Center displays this location information to Communications Officers.
  • This location information must meet FCC accuracy standards – generally, it must be accurate to within 50-300 meters (depending on the type of technology used).

If you use a de-activated cell phone to make a 911 call, the Communications Officer may not be able to accurately and automatically determine your location. And because wireless 911 location information will not be available everywhere immediately, it is important for citizens calling 911 from cell phones to remember the following:

  • Tell the Communications Officer the exact location of the emergency right away. Marion County Communications Officers will immediately ask you  "What is the exact address of your emergency?"
  • Give the Communications Officer your cell  phone number so that if the call gets disconnected, the operator can call you back. Marion County Communications Officers will ask you "What is your phone number?" even if it is displayed on the screen. This is to verify that the number we are seeing is, in fact, the number you are calling from.
  • If your cell phone is not “initialized” (i.e., you do not have a contract for service with a wireless service provider), and your emergency call gets disconnected, you must call the emergency operator back because he or she does not have your telephone number and cannot contact you. Remember  a "deactivated" cell phone WILL still call 911 so do not give it to your child to play with unless you are sure there is no power to it. 
  • Refrain from programming your phone to automatically dial 911 when one button, such as the “9” key, is pressed. Unintentional cell 911 calls, which often occur when auto-dial keys are inadvertently pressed, cause problems for emergency services call centers.
  • If your cell phone came preprogrammed with the auto-dial 911 feature already turned on, turn off this feature.
  • Lock your keypad when you’re not using your cell phone. This also prevents accidental calls to 911.

The FCC set a Dec. 31, 2005 deadline for wireless carriers to comply with Phase Two E911 rules. Wireless carriers may comply with certain FCC E911 rules by ensuring that 95% of their customer's phones are E911-capable. The FCC’s E911 rules do not specify precisely how carriers may achieve this compliance. Some carriers may provide various incentives or policies to encourage customers without location-capable phones to obtain new, location-capable phones.