[VoiceOps] Mobile phone location info

[Alex Balashov]

Jim Haney wrote:

> Is there any way to find the physical location of a mobile phone to 
> within 15 or so miles? We're a basic SIP shop, but I was wondering if 
> something like SS7 would get me some of that info. I don't want to rely 
> on GPS or wi-fi, and it doesn't have to be precise. Mostly just trying 
> to find out what city the phone is in.

No, cell tower triangulation (not very precise) and GPS (quite precise) 
are the only means available to locate cell phones technologically, and 
those are available only to operators.

Triangulation can be done passively, but its precision varies 
considerably, although the tolerance is certainly within 15 mi.  GPS 
coordinates require triggering some action on the phone to transmit the 
location it has determined itself to hold via the GPS signal to the 
network, which is done on many phones in case of a 911 call and/or by 
way of various special applications (Google Maps overlay, etc.)

SS7 does not carry any information as to the location of the handset or 
any of its specific characteristics, nor does its message format contain 
any support for that.  It is designed purely for interoperation between 
telco network elements.

-- 
Alex Balashov - Principal
Evariste Systems
Web     : http://www.evaristesys.com/
Tel     : (+1) (678) 954-0670
Direct  : (+1) (678) 954-0671