On Sun, 04 Jun 2006 16:03:17 +0100, Derek ^
wrote:
>>Do you also deny that mobile phones contain the technology to
>>determine their location,
>
>The dont really. All the phone does is periodically page the network,
>or respond to the network paging it, (dont know which could be both).
>
>> and that such technology is not necessary for the normal operation of the
phone?
>
>Its obvious its necessary, the network has to know which cellsites
>the phone is reachable from so it can set up a connection when theres
>an incoming call. The networks seem to use this info in an intelligent
>way, a call to a mobile that has been switched off all day goes
>straight to voicemail IME whereas a call to a mobile thats just gone
>out of signal in an underpass say seems to get retried.
You obviously do not know of the phase difference technology that has
been in use for some time. Prior to that, it was possible to know
which cell the phone was in, and perhaps make a guess as to how far
away the phone is from the base by its signal strength.
What you can do these days is to send a specific locate signal to
the phone. The phone will then proceed to receive two or three base
station service signals (provided there is more than one within
range). Using the difference in time between the synchronised base
signals, it can determine its relative position to an accuracy of
about 100m. There is an ambiguity when only 2 base stations are
within range, which can usually be resolved by using other factors.
--
Cynic
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Posted: 2006-06-04 16:47:26
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