[e2e] 911 and cell phones

Black_David@emc.com Black_David at emc.com
Fri Apr 1 06:11:04 PST 2005


It's too bad that California screwed this up.  I know from
actual experience that calling 911 from at least my cell
phone in Mass. enables one to reach the state police in 
short order.

As for "exact position" of a cell phone, I think that's a red
herring, because the only way to get it accurately appears to
involve a GPS receiver in the cell phone, which most cell
phones don't have.  While I'm not an expert, my impression
from what I've seen is that triangulation based on location
of cell site antennas has not been sufficiently workable
in practice.  Even GPS has its limits - if the receiver can't
see enough satellites, the result is a 2-D fix instead
of 3-D, which can be a problem in a multi-story building.

OTOH, if you want to trust your life to a global SLP
infrastructure (Uh, where can I find one of those?),
that's your choice ...

David L. Black, Senior Technologist
EMC Corporation, 176 South St., Hopkinton, MA  01748
+1 (508) 293-7953             FAX: +1 (508) 293-7786
black_david at emc.com        Mobile: +1 (978) 394-7754

> -----Original Message-----
> From: end2end-interest-bounces at postel.org 
> [mailto:end2end-interest-bounces at postel.org] On Behalf Of 
> David P. Reed
> Sent: Thursday, March 31, 2005 1:13 PM
> To: Alex Cannara
> Cc: end2end-interest at postel.org
> Subject: Re: [e2e] Skype and congestion collapse.
> Alex - the underlying assumption is that traditional telephony delivers 
> 911 functionality best.   Well, the word on the street is that in 
> California, if you call 911 on your basic, non IP cell phone, your exact 
> position is delivered to ... well, no one knows where, but it's a place 
> that has no capability to actually transfer that information to anyone 
> who actually can help you in an emergency.   Better to call directory 
> assistance for the phone number of your local police dept. and hope they 
> don't tell you "911", because that will guarantee 30-90 minutes of 
> screwing around.
> OK, maybe wired phones still do 911 OK, but do PBXes?   I doubt it - so 
> the point about bosses may be bogus as well.
> Here the argument that 911 should be "in the network" fails.  I'd much 
> rather have my actual physical telephone be smart enough to figure out 
> how to summon emergency services (perhaps finding the doctor who is in 
> the next cubicle over if the SLP emergency service existed), I think.
> Dale Hatfield points out that the phone companies have made it 
> *impossible* to deploy a "911-like" service over the WWW, because who 
> can trust that a person would actually tell the truth that they have a 
> life or death situation on their hands.   But of course we can ALL trust 
> Verizon Wireless with our lives... yeah right.

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