Richard Barnes & Brian Rosen IEEE Spectrum April 2014 IS 376 November 13, 2014
911 for the 21st Century IS 376 November 13, 2014 Page 2 Basic 911 Started in the 1960s on a community-by-community basis, 911 emergency calls originally were routed through the telephone exchange system to an emergency communications center (a Public Safety Answering Point), where a call taker would look up the appropriate emergency number in a book and route the call.
911 for the 21st Century IS 376 November 13, 2014 Page 3 Enhanced 911 The process became more automated in the 1980s, when 911 calls were routed to a specialized router that would immediately direct them to the correct Public Safety Answering Point, based on the location of the caller. The E911 system was reliant on landlines, however, and wouldn’t work with the newly developing mobile phone system. This was remedied in the 1990s by having each mobile phone company set up a Mobile Positioning Center which assigns each 911 call a fake landline number that allows the correct PSAP to be contacted. The PSAP coordinates with the MPC, which uses GPS data, triangulation between cell towers, or (as a last resort) the cell tower address to localize the caller.
911 for the 21st Century IS 376 November 13, 2014 Page 4 E911 Status – April 2013
911 for the 21st Century IS 376 November 13, 2014 Page 5 East Coast Derecho – June 2012 When a fast-moving storm (called a derecho) hit several states in June 2012, it resulted in 22 deaths, widespread damage, and large-scale E911 communications failures. The sharp increase in reports to the Network Outage Reporting System were ultimately attributed to the failure of backup power systems designed to maintain service during commercial power outages. The E911 dependency on the circuit-switched wireline network increased its vulnerability, which wasn’t helped by poor maintenance of backup cell batteries.
911 for the 21st Century IS 376 November 13, 2014 Page 6 Multistate Outage – April 2014 On April 9, 2014, a call-routing facility in Englewood, Colorado, stopped directing emergency calls to eighty-one 911 call centers (Public Safety Answering Points) in seven states. The outage was caused by a software failure in the Colorado facility, and resulted in a loss of 911 service for more than 11 million people for up to six hours. Over 6,600 calls to 911 never reached a PSAP.
911 for the 21st Century IS 376 November 13, 2014 Page 7 Wireless E911 Mislocation FCC data from July-September 2013 indicate that the vast majority of wireless 911 calls in Washington D.C. were unable to locate the caller’s longitude and latitude (although they could locate the cell tower being used). Cell tower position is unreliable for determining caller position because calls are frequently not picked up by the nearest cell tower.
911 for the 21st Century IS 376 November 13, 2014 Page 8 Next Generation 911 Rather than attempting to retrofit newer Internet and 4G mobile calls to the old PSAP-based E911 system, NG911 adapts the old circuit-switched and 3G mobile calls to fit the new Emergency Services IP Network platform.
911 for the 21st Century IS 376 November 13, 2014 Page 9 NG911 Progress – August 2014
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