punnamas vichitkulwongsa wrote:
> I would love to hear more about this technology that you are talking about.
> When I worked at AT&T Wireless and Ericsson, we tested many positioning
> technologies. If you are talking about time alignment factor both on GSM and
> TDMA, and even with neighboring cell information, and even combine it with
> smart array antenna technology, I doubt if you can get close to 15 meter
> accuracy. Given the moving vehicle speed or even walking speed, I`m curious
> to learn about how the technology can get to 1 m precision. So please share
> with me about the technology you are talking about.
Too much "I worked" and "I doubt" in your reply...how old is
your information? The technology involved does not work
by simply put some cells somewhere, you need to know the
environment very well...simply spoken:
Look ahead technology. Compare streetmaps, house locations,
most used places by phone carriers (people), user behaviour, weak net
access points, magnetic field of the earth, run time lengths and more
parameter in a powerful computer, mix it, blend it, shake it and
calculate the exact location (also the height of a phone in buildings)
of a mobile phone.
Funny side effect: this works great with moving objects, but not
with fixed objects. With fixed objects you lose focus over time
(read microseconds) and than you are right...15 meter is the
average.
Be sure that this system is not invented nor used by a Telco
and specially not for the announced location system, it's still
too expensive. And who has so much money to invent a system like
this? Right.
J.
Received on Mon Aug 21 19:25:35 2000