[Geowanking] Re: E911 // cellular trilateration accuracy

[Anthony Townsend]

It's the FCC not the FAA, and my understanding is that none of the US
carriers are using tower triangluation (EOTD or other variants) because of
the cost of network upgrades. Instead they are pushing to cost to you, the
consumer, in the form of A-GPS equipped handsets.



roger at sylvanascent.com (roger at sylvanascent.com) wrote @ 4/10/06 9:35 AM:

> I think this is a great question. I talked to a gentleman from South Africa
> last year at Where 2 who claimed to be a GSM expert. He said that GSM can
> locate you within something like 3 meters with no GPS support just using
> the towers, and that this was built into the GSM spec. He spoke of a case
> in South Africa where they located some sort of criminal using the GSM
> records.
> 
> He said that CDMA on the other hand, cannot locate so precisely.
> 
> So, to me, A-GPS was designed to make CDMA users locatable to the same
> degree as GSM.
> 
> As an aside, does anyone know which type of cell phones are more lethal?
> 
> Roger
> 
> Original Message:
> -----------------
> From: Ian | Urban Mapping ian at urbanmapping.com
> Date: Mon, 10 Apr 2006 01:42:23 -0400
> To: geowanking at lists.burri.to
> Subject: [Geowanking] E911 // cellular trilateration accuracy
> 
> 
> At the risk of asking (another) obvious question, I continue my naïve streak
> on this listservŠ
> 
>  
> 
> I¹ve heard very different reports of how accurate cellphone tracking is‹the
> FAA mandates something like 50% of calls must be traceable to within a range
> of 30m but I¹ve heard some mobile pros say they¹ve heard of it getting as
> good as several feet. Obviously this varies depending on geography (urban,
> rural, topography), but does anybody have any idea how the US wireless
> carriers stack up? And how does this compare to phones with GPS?
> 
>  
> 
>  
> 
> Ian White  ::  Urban Mapping LLC  ::   <mailto:ian at urbanmapping.com>
> ian at urbanmapping.com
> 
> 120 West 45th Street  20th Floor  ::  New York  NY  10036
> 
> Tel.212.242.8267  :: Fax.866.385.8266  ::  www.urbanmapping.com
> 
>  
> 
> 
> 
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