The original 911 system was rolled out when many phone switches were electromechanical. Step-by-step and crossbar offices didn't log calls, didn't pass line identification data with the call, and couldn't route based on the source of the call. But they had hard-wired relay logic in the originating registers (the units that receive dial digits) to recognize area codes (second digit 1 or 0 back then) and service numbers (second and third digits 1). Those were forwarded to a toll office, along with automatic line identification info. So 911 was forwarded to a toll office, like a long distance call. "999" was considered as the emergency number; the UK used that. But US switches didn't have a special case for 999, so that was hard to retrofit. Hence 911.<p>Toll offices, which handled long distance calls, were computerized by then. They could be upgraded to deal with 911 routing. This requires a database to map phone numbers to the appropriate Public Safety Answering Point. The idea of having a computer with a disk drive in the call chain was radical at the time, but it was made to work. The original computers for this were Western Electric 3B machines, set up as duplex pairs.<p>The toll office 911 system became a problem with the breakup of AT&T. AT&T retained most of the toll switches, while the local exchange carriers got the local offices. (Now, of course, with weak antitrust enforcement, they've all merged back together again.)
My job is upgrading and maintaining 911 and other life safety systems.<p>The article is correct, advancing technologies are not reflected by additional capabilities by PSAPs, DISA's or ILEC's (The ppl that foward your call to a responder). It was only recently that IP based 911 sending of ANI/ALI (Telephone/Location data) data has been implemented on a large scale. In Canada, it ran on an old packet switched network for ages!<p>Their are different flavors of 911. E911 (Enhanced), V911 for VoIP phones, and recently the addition of Wifi based calling among others. The original 911 systems was designed when phones were static, they didn't move. Nowadays, with cell, voip and now, wifi devices, theirs no telling where the call (device) originates from. Yes, most send long/lat data, but that is based on triangulation of cell towers and not accurate enough. To further complicate things, long/lat doesn't take into account altitude. In a urban setting, the responders maybe at ground level wondering just which building and floor originated the call (yes, their systems to deal with this but not widely implemented, and, failing that, if the caller is unable to speak, you have a larger issue).<p>Most responders don't even have the ability to map a long/lat. So at this point, the accuracy is moot.<p>All that being said. The E911 system works well. Cell/VoIP/Wifi, not so much. The call will generate a response, but it's hardly efficient.
There's some interesting technical history behind some of the emergency number choices:<p>999 in the UK (from 1937) was chosen because public payphone could be easily modified to make it a free call.<p>111 in New Zealand (from 1958) was chosen because the system was implemented using British Post Office equipment that already supported 999. But New Zealand phones pulsed in reverse so 111 on a New Zealand phone produced the same pulse as 999 on a British phone.<p>000 in Australia (from 1961) was chosen because 0 was already used for trunk access. On an automated rural exchange, 0 would connect you to a main centre. In remote communities it was 00. This meant that dialing 000 through an existing remote exchange would at least connect you to an operator in a main centre.
I once worked at a bourgeoning hosting provider who had one of the higher floors in a building that was condemned, but couldn't be torn down because it was home to a phone switching room that had been a part of the original 911, and the designers of technology then <i>simply did not</i> even imagine their systems being EOLed, so it turns out, no living or dead being knows how. I'm curious to know if that's still standing.<p>The freight elevator shaft had a shattered wooden freight elevator carriage at the bottom of it. We took the stairs.
If you want to see an emerging country try it nowadays, look at the Philippines.<p>They basically gave up. Though the telecoms are a duopoly.
Only working 911 system is in Davao.<p>Everywhere else you have independent short codes like 117 which may not be answered. Ironic for most of the BPO is outsourced call center agents.<p>Then the second issue are jokes,<p><a href="http://news.abs-cbn.com/news/08/01/16/dial-8888-911-govt-opens-complaints-emergency-hotlines" rel="nofollow">http://news.abs-cbn.com/news/08/01/16/dial-8888-911-govt-ope...</a><p>"Hotline 911 received 2,475 recorded calls, between 12 a.m. to 7 a.m. Monday.
Out of the total, only 75 calls were legitimate while the 1,119 were dropped and 1,356 were prank calls."<p>In other news, I've not yet needed it.
An example of the drawbacks of decentralization - meanwhile in Sweden, 98% of phones were already covered by the "90 000" emergency number by 1965.