Re: [Geowanking] Re: E911 // cellular trilateration accuracy

Wed, 12 Apr 2006 13:37:14 -0700

Speaking of Verizon's A-GPS... Is there any way we can get access to this yet? And if not, is there any open source projects that are using tower data?

i'd be real surprised if there was any way to get access to Verizon's data (and for free - ha!).  

as for determining location based on GSM tower info, check out what Intel Research in Seattle is doing with PlaceLab  (think: wardriving w/ GSM modems).  it requires a pre-existing data set (GSM towers mapped to lat/longs) and the PlaceLab client running on your device, but once the data is collected i've heard the resolution is around 10 feet or so.


(ps:  i think the only available data set is Seattle... anyone know otherwise about NYC?)

/d
____________
dennis crowley
founder, dodgeball.com

+ 917-301-2028
____________

On Apr 12, 2006, at 4:24 PM, Kevin Elliott wrote:

Speaking of Verizon's A-GPS... Is there any way we can get access to this yet? And if not, is there any open source projects that are using tower data?

Kevin

On Apr 12, 2006, at 12:32 PM, Dan Melinger wrote:

Out of the larger carriers in the US, it's my understanding that Verizon and Sprint are using A-GPS and the GSM guys, T-Mobile and Cingular are using alternative technology like Uplink Time Difference of Arrival (U-TDOA) technology provided by TruePosition.

A-GPS requires a chip in the phone while U-TDOA doesn't.


On Apr 12, 2006, at 12:46 PM, Anthony Townsend wrote:

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.



[EMAIL PROTECTED] ([EMAIL PROTECTED]) 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 [EMAIL PROTECTED]
Date: Mon, 10 Apr 2006 01:42:23 -0400
Subject: [Geowanking] E911 // cellular trilateration accuracy


At the risk of asking (another) obvious question, I continue my naïve streak
on this listserv…



I’ve 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 I’ve heard some mobile pros say they’ve 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:[EMAIL PROTECTED]>

120 West 45th Street  20th Floor  ::  New York  NY  10036

Tel.212.242.8267  :: Fax.866.385.8266  ::  www.urbanmapping.com





--------------------------------------------------------------------
mail2web - Check your email from the web at


_______________________________________________
Geowanking mailing list

_______________________________________________
Geowanking mailing list

| dan melinger
| kamida :: socialight

| office +1 212 561 5155
| cell +1 917 494 5856
| skype melinger

_______________________________________________
Geowanking mailing list

_______________________________________________
Geowanking mailing list

_______________________________________________
Geowanking mailing list
[email protected]
http://lists.burri.to/mailman/listinfo/geowanking

Reply via email to