[rescue] VOIP

N.Miller vraptor at promessage.com
Mon Oct 13 01:35:03 CDT 2003

On Sunday, October 12, 2003, at 10:34 PM, Geoffrey S. Mendelson wrote:

> sammy ominsky wrote:
>> The 911 thing makes sense. 911 calls are automatically routed to the
>> nearest emergency call center, and if your phone is routed through a
>> server in California or New Jersey, how can you reach the right 
>> center?
> How about a cell phone? For example, GSM cell phones will make 
> emergency
> calls without a SIM (subscriber ID module), so you don't need an 
> account
> or service, just a signal. In the U.S. and Canada, the phones are 
> programed
> for 911, phones for the rest of the world use 112,
> With GSM, it's part of the Service Providers contract with the GSM
> associtation. I think there is a law in the U.S. that requires 911
> service from all SP's.
> If I remember correctly, an AMPS (old style analog cell phone) has to 
> be
> able to make 911 calls until sometime in 2005 in the U.S. without 
> needing
> a service contract.

Yes, any cell phone has to be able to make a 911 call, but
that doesn't solve the "where are you?" problem.  911 can be
routed oddly through the cell towers, so there is no guarantee
you will get a local 911 dispatcher.

Consumer Reports had a report on a field test of 911 from cell
phones at the end of last year. The test was done in the North
Eastern part of the US.  In some cases, they got 911 dispatch
from the next county over.

All cell phones are also supposed to work in analog mode, but
most people don't know that on modern GSM/TDMA/PCS/CDMA phones
you have to force them into analog.  (For instance, if you have
a Nextel phone, and need 911, but are out of Nextel coverage,
the only way you can get 911 if there are other carriers
available is by forcing the phone into analog mode.)

Not a problem if the person dialing 911 is able-bodied, but what
if it's a 5 y-o who doesn't know the address or someone who is
blind (in a car/on the street) or deaf?

Not an easy problem to solve.


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