Archived from groups: alt.cellular.cingular (
More info?)
Dick wrote:
> On Wed, 30 Mar 2005 23:48:03 -0600, Jer <gdunn@airmail.ten> wrote:
>
>
>>>It does have the ability to send your location to the network during
>>>an emergency call. Indicators on the screen show when your phone is
>>>sending location information. Page 26 in the manual. I don't know if
>>>GPS is involved, but somehow it knows where it is.
>>>
>>>Dick
>>
>>The phone itself doesn't do anything extraordinary, it's a radio that
>>transmits a signal. But, that signal is used by the cellular system to
>>extrapolate the location of the transmitter, and only when 911 is
>>dialed. The cellular system is calibrated with GPS using pre-tested
>>transmitters, and the location results are stored for subsequent
>>comparisons to other transmitters when necessary.
>>
>>http://www.trueposition.com is helpful.
>
>
> An interesting site. Thanks. It indicates that any phone on the
> Cingular network works with E-911 when it is available. What then is
> the V551 doing that is different from an ordinary cel phone? When it
> sends location information to the network a little icon comes on the
> screen. Is it receiving information from the towers and doing its own
> extrapolation, then sending that back to the towers? It's obviously
> doing something that a common cel phone can't do.
>
> Dick
My understanding from an accomplice... er... ^H^H^H friend that works
for Cingular, the 551 doesn't do anything different than any other GSM
phone. The iconic symbol you're referring to does appear from time to
time, and for some reason someone decided the 551 display (and maybe
others) needed an indicator for this. When powered on, all handsets
constantly listen to a control signal from whichever cell it's homed on,
and occasionally the handset thinks that signal is weak. This
'self-assisted' homing function is nothing more than the handset
soliciting assistance from the cellular GSM network to determine if an
inactive hand-off should be performed, and this occurs more frequently
when moving around. If the network honors the request, it then polls
the handset for signal quality tests (hence the buzzing sound in nearby
audio equipment) and then a decision is made by the network whether to
track the handset from a different BTS or not. The whole point of all
this is an attempt to maintain a good connection in a radio network, and
there's nothing nefarious about it.
--
jer
email reply - I am not a 'ten'