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An operator takes a call at the Jackson, Tennessee 911 Dispatch Center.

9-1-1 is the emergency telephone number for the North American Numbering Plan (NANP), one of eight N11 codes. This number is intended for use in emergency circumstances only, and to use it for any other purpose (including non-emergency situations[citation needed] and prank calls) can be a crime.[1][2]


In the earliest days of telephone technology, prior to the development of the rotary dial telephone, all telephone calls were operator-assisted. To place a call, the caller was required to pick up the telephone receiver and wait for the telephone operator to answer, they would then ask to be connected to the number they wished to call, the operator would make the required connection manually, by means of a switchboard. In an emergency, the caller might simply say "Get me the police", "I want to report a fire", or "I need an ambulance/doctor". Until dial service came into use, one could not place calls without operator assistance.[3]

"Emergency 911" displayed on the side of an Upper Dublin Township police vehicle, indicating that 9-1-1 is the number to dial in the event of an emergency.

The first known experiment with a national emergency telephone number occurred in the United Kingdom in 1937, using the number 999.[4] The first city in North America to use a central emergency number (in 1959) was the Canadian city of Winnipeg, Manitoba, which instituted the change at the urging of Stephen Juba, mayor of Winnipeg at the time.[5] Winnipeg initially used 999 as the emergency number,[6] but switched numbers when 9-1-1 was proposed by the United States. In the United States, the push for the development of a nationwide American emergency telephone number came in 1957 when the National Association of Fire Chiefs recommended that a single number be used for reporting fires.[7] In 1967, the President's Commission on Law Enforcement and Administration of Justice recommended the creation of a single number that could be used nationwide for reporting emergencies.[8] The burden then fell on the Federal Communications Commission, which then met with AT&T in November, 1967 in order to come up with a solution.

In 1968, a solution was agreed upon. AT&T chose to implement the concept, but with its unique emergency number, 9-1-1, which was brief, easy to remember, dialed easily, and worked well with the phone systems in place at the time.

Just 35 days after AT&T's announcement, on February 16, 1968, the first-ever 9-1-1 call was placed by Alabama Speaker of the House Rankin Fite, from Haleyville City Hall, to U.S. Rep. Tom Bevill, at the city's police station. Bevill reportedly answered the phone with "Hello". At the City Hall with Fite was Haleyville mayor James Whitt; at the police station with Bevill were Gallagher and Alabama Public Service Commission director Eugene "Bull" Connor. Fitzgerald was at the ATC central office serving Haleyville, and actually observed the call pass through the switching gear as the mechanical equipment clunked out "9-1-1". The phone used to answer the first 9-1-1 call, a bright red model, is now in a museum in Haleyville, while a duplicate phone is still in use at the police station.

Public notice on highway

In 1968, 9-1-1 became the national emergency number for the United States. Calling this single number provided a caller access to police, fire and ambulance services, through what would become known as a common Public-safety answering point (PSAP). The number itself, however, did not become widely known until the 1970s, and many municipalities did not have 9-1-1 service until well into the 1980s.[citation needed] Conversion to 9-1-1 in Canada began in 1972 and now virtually all areas, except for some rural areas,[which?] are using 9-1-1. Each year, Canadians make 12 million calls to 9-1-1 (as of 2008).[9]

On September 15, 2010, AT&T announced that State of Tennessee has approved a service to support a Text to 9-1-1 trial statewide, where AT&T would be able to allow its users to send text messages to 9-1-1 Public-safety answering points (PSAPs).[10]

Most British Overseas Territories using the North American Numbering Plan, like Anguilla, Bermuda, the British Virgin Islands and the Cayman Islands use 911.

Locating callers automatically[edit]

The Enhanced 9-1-1 System

In over 98 percent of locations in the United States and Canada, dialing "9-1-1" from any telephone will link the caller to an emergency dispatch center—called a PSAP, or Public Safety Answering Point, by the telecom industry—which can send emergency responders to the caller's location in an emergency. In most areas (approximately 96 percent of the US) enhanced 9-1-1 is available, which automatically gives the dispatcher the caller's location, if available.[11]

Wireline enhanced 9-1-1[edit]

In all North American jurisdictions, special privacy legislation permits emergency operators to obtain a 9-1-1 caller's telephone number and location information.[12] This information is gathered by mapping the calling phone number to an address in a database. This database function is known as Automatic Location Identification (ALI).[13] The database is generally maintained by the local telephone company, under a contract with the PSAP. Each telephone company has its own standards for the formatting of the database. Most ALI databases have a companion database known as the MSAG, Master Street Address Guide. The MSAG describes address elements including the exact spellings of street names, and street number ranges.

Each telephone company has at least two redundant telephone trunk lines connecting each host office telephone switch to each PSAP. These trunks are either directly connected to the PSAPs, or are connected to a telephone company central switch that intelligently distributes calls to the PSAPs. These special switches are often known as 9-1-1 Selective Routers.[14] The use of 9-1-1 Selective Routers is becoming increasingly more common, as it simplifies the interconnection between newer office switches and the many older PSAP systems.

The effectiveness of this technology may sometimes be affected by the type of telephone infrastructure that the call is routed through. The PSAP may receive calls from the telephone company on older analog trunks, which are similar to regular telephone lines but are formatted to pass the calling party number. The PSAP may also receive calls on older-style digital trunks, which must be specially formatted to pass Automatic Number Identification (ANI) information only.[15] Some upgraded PSAPs can receive calls in which the calling party number is already present. The location of the call is drawn from a computer routine which supports telephone company service billing, called the Charge Number Parameter. With some technologies, the PSAP trunking does not pass address information along with the call. Instead, only the calling party number is passed, and the PSAP must use the calling party number to look up the address in the ALI database. The ALI database is secured and separate from the public phone network, by design. Sometimes, on calls using land lines, the originating telephone number may not be passed to the PSAP at all, generally because the number is not in the ALI database. When this happens, the call receiver must confirm the location of the incoming call, and may have to redirect the call to another, more appropriate PSAP. ALI Failure occurs when the phone number is not passed or the phone number passed is not in the ALI database. In most jurisdictions, when ALI database lookup failure occurs, the telephone company has a legal mandate to fix the database entry.

Wireless enhanced 9-1-1[edit]

9-1-1 CAD[edit]

9-1-1 Dispatchers use "CAD" Computer-Aided Dispatch to keep a log of police, fire, and EMS services.

In the United States[edit]

In 1996, the U.S. Federal Communications Commission (FCC) issued an order requiring wireless carriers to determine and transmit the location of callers who dial 9-1-1. The FCC set up a phased program: Phase I involved sending the location of the receiving antenna for 9-1-1 calls, while Phase II sends the location of the calling telephone. Carriers were allowed to choose to implement 'handset based' location by Global Positioning System (GPS) or similar technology in each phone, or 'network based' location by means of triangulation between cell towers. The order set technical and accuracy requirements: carriers using 'handset based' technology must report handset location within 50 meters for 67% of calls, and within 150 meters for 90% of calls; carriers using 'network based' technology must report location within 100 meters for 67% of calls and 300 meters for 90% of calls.

The order also laid out milestones for implementing wireless location services. Many carriers requested waivers of the milestones, and the FCC granted many of them. By mid-2005, implementation of Phase II was generally underway, limited by the complexity of coordination required from wireless and wireline carriers, PSAPs, and other affected government agencies; and by the limited funding available to local agencies which needed to convert PSAP equipment to display location data (usually on computerized maps).

In July 2011, the FCC announced that after an eight-year implementation period, at some yet-to-be-determined date in 2019, wireless carriers will no longer be allowed to use 'network based' location techniques, requiring instead that they use 'handset based' location with GPS or similar technology.[16]

Funding 9-1-1 services[edit]

In Canada, a similar fee for service structure is regulated by the federal Canadian Radio Television and Telecommunications Commission (CRTC). Depending on the location, counties and cities may also levy a fee, which may be in addition to, or in lieu of, the federal fee. The fees are collected by local telephone and wireless carriers through monthly surcharges on customer telephone bills. The collected fees are remitted to 9-1-1 administrative bodies, which may be statewide 9-1-1 boards, state public utility commissions, state revenue departments, or local 9-1-1 agencies.[17] These agencies disburse the funds to the Public Safety Answering Points for 9-1-1 purposes as specified in the various statutes. Telephone companies in the United States, including wireless carriers, may be entitled to apply for and receive reimbursements for costs of their compliance with federal and state laws requiring that their networks be compatible with 9-1-1 and enhanced 9-1-1.

Emergency service response[edit]

Reaching a 9-1-1 dispatcher does not guarantee that emergency services will actually be able to respond to the call, as they are funded and operated separately. One egregious example occurred during a budget crunch in Josephine County, Oregon in 2013, when no county police were on duty and no state police were available to respond to a female caller whose abusive ex-boyfriend was in the process of breaking into her apartment. After the caller spent ten minutes on the phone with the dispatcher, the ex-boyfriend succeeded in breaking in and raping her.[18]

In 2013, the next of kin of Detroit murder victim Stacey Hightower sued the city for its 90-minute 9-1-1 response time.[19] For Robert Poff, a patient experiencing problems breathing, a twenty-minute delay in summoning emergency medical aid proved fatal.[20] Police emergency response times in the bankrupt city in 2013 were typically fifty minutes[21] to one hour[22] and ambulance response times at least twelve to twenty minutes.[23]

Problems requiring further resolution[edit]

Inactive telephones[edit]

In the U.S., Federal Communications Commission rules require every telephone that can access the network to be able to dial 9-1-1, regardless of any reason that normal service may have been disconnected (including non-payment) (This only applies to states with a Do Not Disconnect policy in place. Those states must provide a "soft" or "warm" dial tone service, details can be found at FCC[24] On wired (land line) phones, this usually is accomplished by a "soft" dial tone, which sounds normal but will allow only emergency calls. Often, an unused and unpublished phone number will be issued to the line so that it will work properly. With regard to mobile phones, the rules require carriers to connect 9-1-1 calls from any mobile phone, regardless of whether that phone is currently active.[25] The same rules for inactive telephones apply in Canada.[26]

When a cellular phone is deactivated, the phone number is often recycled to a new user, or to a new phone for the same user. The deactivated cell phone will still complete a 9-1-1 call (if it has battery power) but the 9-1-1 operator will see a specialized number indicating the cell phone has been deactivated. It is usually represented with an area code of (911)-xxx-xxxx. If the call is disconnected, the 9-1-1 operator will not be able to connect to the original caller. Also because the cell phone is no longer activated, the 9-1-1 operator is often unable to get Phase II information.[27]

Internet telephony[edit]

If 9-1-1 is dialed from a commercial Voice Over Internet Protocol (VoIP) service, depending on how the provider handles such calls, the call may not go anywhere at all, or it may go to a non-emergency number at the public safety answering point associated with the billing or service address of the caller.[28] Because a VoIP adapter can be plugged into any broadband internet connection, a caller could actually be hundreds or even thousands of miles away from home, yet if the call goes to an answering point at all, it would be the one associated with the caller's address and not the actual location of the call. It may never be possible to reliably and accurately identify the location of a VoIP user, even if a GPS receiver is installed in the VoIP adapter, since such phones are normally used indoors, and thus may be unable to get a signal.

In March 2005, commercial Internet telephony provider Vonage was sued by the Texas Attorney General, who alleged that their website and other sales and service documentation did not make clear enough that Vonage's provision of 9-1-1 service was not done in the traditional manner. In May 2005 the FCC issued an order requiring VoIP providers to offer 9-1-1 service to all their subscribers within 120 days of the order being published.[29] The order set off anxiety among many VoIP providers, who felt it will be too expensive and require them to adopt solutions that won't support future VoIP products.[citation needed] In Canada, the federal regulators have required Internet Service Providers (ISPs), to provide an equivalent service to the conventional PSAPs, but even these encounter problems with caller location, since their databases rely on company billing addresses.[30]

In May 2010, most VoIP users who dial 9-1-1 are connected to a call center owned by their telephone company, or contracted by them. The operators are most often not trained emergency service providers, and are only there to do their best to connect the caller to the appropriate emergency service. If the call center is able to determine the location of the emergency they try to transfer the caller to the appropriate PSAP. Most often the caller ends up being directed to a PSAP in the general area of the emergency. A 9-1-1 operator at that PSAP must then determine the location of the emergency, and either send help directly, or transfer the caller to the appropriate emergency service. In April 2008, an 18-month-old boy in Calgary, Alberta died after a VoIP provider's 9-1-1 operator had an ambulance dispatched to the address of the boy's family's ISP, which is in Mississauga, Ontario.[31]


The US Federal Bureau of Investigation has warned of an increase in deliberate false alarms in which a false origin is displayed on calls to emergency services to send SWAT teams or heavily armed police to unsuspecting citizens' doorsteps.[32] Voice over IP has contributed greatly to the problem by making call origin more difficult to determine quickly and reliably. In California, state governor Jerry Brown has signed legislation imposing liability for the full cost of these false alarms, which can reach $10000 or more per incident.[33]

Emergencies across jurisdictions[edit]

When a caller dials 9-1-1, the call is routed to the local public safety answering point. However, if the caller is reporting an emergency in another jurisdiction, the dispatchers may or may not know how to contact the proper authorities. The publicly posted phone numbers for most police departments in the U.S. are non-emergency numbers that often specifically instruct callers to dial 9-1-1 in case of emergency, which does not resolve the issue for callers outside of the jurisdiction. In the age of both commercial and personal high speed Internet communications, this issue is becoming an increasing problem.

NENA has developed the North American 9-1-1 Resource Database which includes the National PSAP Registry. PSAPs can query this database to obtain emergency contact information of a PSAP in another county or state when it receives a call involving another jurisdiction. Online access to this database is provided at no charge for authorized local and state 9-1-1 authorities.[34]


In the 919 area code, including Raleigh, North Carolina and surrounding communities, a second area code (984) was added using an overlay plan in 2011. Starting in March 2012, people making calls from the 919 area code had to dial the entire number including area code even for local calls, and many people started with 9-1-1, realized their mistake, and disconnected. Three months after the change, police in Wake County were responding to six times as many "hang-ups", all of which required a response. This response could be a call-back from the dispatcher (slowing down the ability to respond to actual emergencies), or if that did not get a result, a visit from the police. A supervisor recommended that people remain on the line and explain the mistake.[35][36] For all of 2012, the number of hang-ups in Wake County was nearly three times what it had been before the switch; over 30,000 police responses resulted.[37]

PBX systems can be a problem, when a "9" is required to reach an outside line and "1" used to indicate an area code, and either the telephone buttons have bouncy contacts or the person is jittery and accidentally presses a button multiple times. So, if they end up dialing 9-9-1-1 (rather than 9-1), the first 9 connects to the outside network, and then a 9-1-1 call is placed.

Making calls public[edit]

News programs and such shows as Rescue 911 have broadcast actual calls to 9-1-1 centers.

Ohio Senator Tom Patton introduced a bill in 2009 which would have banned the broadcasting of 9-1-1 calls, requiring the use of transcripts instead. Patton believed that people would be reluctant to make calls because of possible retaliation or threats against those who called. He intended to seek proof of this idea to satisfy those who did not believe him, or that broadcasting 9-1-1 calls hurt investigations. The Ohio Fraternal Order of Police supported the bill because broadcasts of 9-1-1 calls have been "sensationalized".[38] Ohio Association of Broadcasters director Chris Merritt said government did not have the right to decide how public records were used.[39] Other opponents of such a ban point out that recordings hold dispatchers accountable and show when they are not doing their jobs properly, in a way transcripts cannot.[40][41]

A bill signed by Alabama governor Bob Riley on April 27, 2010 requires a court order before recordings can be made public. Alaska, Florida, Kentucky and Wisconsin also had bills banning the broadcasts.[42] Mississippi, Missouri, Pennsylvania, Rhode Island and Wyoming already banned the broadcasts.[43]

In April 2011, the Tennessee Senate passed a bill banning broadcasts of calls unless the caller gave permission.[44]

North Carolina law defines 911 recordings as public records, but an exception allows officials to release either transcripts or distorted voices.[45]

GPS locator[edit]

According to FCC rule,[which?] by 2018 all phone handsets have to be GPS-capable to better aid in pin-pointing the location of 9-1-1 calls. The rule also proposes using Geolocation software to determine the location of VOIP lines. It's still unclear what the sunset deadline for using old non-GPS phones would be.[46]

However, later reports suggest that this is not true.[47]

See also[edit]


  1. ^ "Police nab fourth teen after hoax 911 calls". CBC News. 2007-10-26. Retrieved 2012-05-22. 
  2. ^ "More arrests possible in prank 911 calls". Canada.com. 2007-10-20. Retrieved 2012-05-22. 
  3. ^ "History of the Telephone (Privateline.com website)". Archived from the original on 15 October 2008. Retrieved 2008-10-16. 
  4. ^ BT plc (2007-06-29). "999 celebrates its 70th birthday". Retrieved 2008-10-16. 
  5. ^ "Winnipeg Police History website". Retrieved 2008-10-16. 
  6. ^ "Winnipegers Call 999 for Help (CBC Digital Archives website". CBC News. Retrieved 2008-10-16. 
  7. ^ "911 Facts 1 (NENA website)". Archived from the original on 2008-08-04. Retrieved 2008-11-03. 
  8. ^ "911 Facts 2 (NENA website)". Archived from the original on 2008-08-04. Retrieved 2008-11-03. 
  9. ^ Robertson, Grant (2008-12-19). "Canada's 9-1-1 emergency". The Globe and Mail (Toronto). Archived from the original on 23 November 2009. Retrieved 2009-11-20. 
  10. ^ "AT&T and State of Tennessee to Launch Text to 9-1-1 Trial". PR Newswire. 2012-09-05. Retrieved 2013-02-17. 
  11. ^ "9-1-1 (FCC website)". Archived from the original on 11 October 2008. Retrieved 2008-11-06.  |
  12. ^ "Washington State Legislature website". Retrieved 2008-10-16. 
  13. ^ "U.S. Patent#6526125 (PatentStorm website)". Retrieved 2008-10-16. 
  14. ^ "Enhanced 9-1-1". Archived from the original on 9 November 2008. Retrieved 2008-11-06. 
  15. ^ "What is ANI? (website)". Archived from the original on 21 October 2008. Retrieved 2008-10-16. 
  16. ^ "FCC 11-107, Notice of Proposed Rulemaking" (PDF). Retrieved 2013-01-11. 
  17. ^ "Santa Cruz County (Calif.) Board of Supervisors website". Archived from the original on 19 October 2008. Retrieved 2008-10-16. 
  18. ^ Amelia Templeton (2013-05-21). "Loss Of Timber Payments Cuts Deep In Oregon". NPR. 
  19. ^ http://www.wxyz.com/dpp/news/region/detroit/lawsuit-to-be-filed-soon-in-detroit-911-dispatch-delay-case
  20. ^ http://www.ems1.com/fire-ems/articles/1456620-Detroit-family-loses-loved-one-questions-EMS-response-time/
  21. ^ http://www.clickondetroit.com/news/detroit-police-chief-to-address-recent-firings-within-department/-/1719418/21159060/-/tx07sp/-/index.html
  22. ^ http://nation.time.com/2013/07/29/detroits-developers-unfazed-by-bankruptcy/
  23. ^ http://www.michigandaily.com/opinion/daily-emergency-responders
  24. ^ "TELEPHONE PENETRATION BY INCOME BY STATE". Fcc.gov. Retrieved 2012-07-08. 
  25. ^ "Denton County (Ga.) 9-1-1 website". Retrieved 2008-10-16. 
  26. ^ "Calling 9-1-1 (City of Calgary website)". Retrieved 2008-10-16. 
  27. ^ "Old cell phones give dispatchers headache". Deseret News. 2007-04-23. 
  28. ^ "911VoIp FAQs". Retrieved 2008-11-03. 
  29. ^ "9-1-1 Services (FCC website)". Archived from the original on 11 October 2008. Retrieved 2008-10-16. 
  30. ^ "CRTC Decision on 9-1-1 Emergency Services for VoIP Service Providers" (Press release). Canadian Radio-television and Telecommunications Commission. 2005-04-04. Retrieved 2009-09-13. [dead link]
  31. ^ CBC News (2008-04-30). "Calgary toddler dies after family calls 911 on internet phone". Retrieved 2009-09-13. 
  32. ^ http://www.fbi.gov/news/stories/2013/september/the-crime-of-swatting-fake-9-1-1-calls-have-real-consequences/the-crime-of-swatting-fake-9-1-1-calls-have-real-consequences
  33. ^ http://www.reuters.com/article/2013/09/10/us-usa-california-swatting-idUSBRE9891I320130910
  34. ^ "NENA 9-1-1 Resource DB". Archived from the original on 8 October 2009. Retrieved 2009-11-06. 
  35. ^ Kenney, Andrew (20 June 2012). "Area-code errors still jam 911 lines; Callers keep hanging up after misdialing 911 for 919, hurting police response times". News & Observer. p. 1B. 
  36. ^ Miller, J.N. (9 July 2012). "Accidental 911 calls persist; Increased misdials heighten stress dispatchers face". News & Observer. p. 1B. 
  37. ^ McMullen, Meghan (19 January 2013). "911 hang-ups still a problem in Wake, county officials say; Misdialed area code might be to blame for errant calls". News & Observer. p. 1A. 
  38. ^ Fields, Reginald (2010-01-11). "State Sen. Tom Patton wants to bar broadcast of 9-1-1 calls". The Plain Dealer. Retrieved 2011-09-01. 
  39. ^ "An end to 911 call replays?". WJW-TV. Retrieved 2011-09-01. [dead link]
  40. ^ "States eye ban on public release of 911 calls". msnbc.com. Associated Press. 2010-02-23. Retrieved 2011-09-01. 
  41. ^ Berke, Ronni; Costello, Carol (2009-05-15). "An end to 911 call replays?". CNN. Retrieved 2011-09-01. 
  42. ^ Andrews, Curry (Spring 2010). "State proposals would limit access to 911 calls". RCFP. 
  43. ^ Carrabine, Nick (2010-04-04). "Legislation would ban broadcast of 911 calls on radio, TV, Web". The News-Herald. Retrieved 2011-08-18. 
  44. ^ "Bill to Protect 911 Callers Passes Tenn. Senate". WTVC. 2011-04-21. Retrieved 2011-08-18. 
  45. ^ "NC § 132‑1 and § 132‑1.4.(c)(4)". Ncleg.net. Retrieved 2013-01-11. 
  46. ^ "FCC To Strengthen Location Accuracy Requirements For All Carriers Using E911 By 2019". October 4, 2011. Retrieved October 5, 2011. 
  47. ^ "Update: GPS Will Not Be Required in All Cell Phones by 2018, FCC Says". October 5, 2011. Retrieved October 19, 2013. 

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