Re: Transrapid Maglev

[Michael Kurkowski <simcard@tig.com.au>]

Aidan Stanger wrote:
> 
> 
> Are you sure they use a doppler system? I can't see how that would work,
> or why they don't just calculate from the strength of the signal
> received (as I thought they did). Even if the mobile phones don't work,
> you can still install phones that do on the trains. No problem.

I think what you will find is that at higher speeds you would be
creating a doppler effect which will play havoc with the GSM phones,
since they require complete accuracy in operation. This is why you find
that from any base station to standard GSM specification you cannot
operate the telephone from further than a 32.5 (is this the exact
figure?) KM radius due to the latency of the signal recieved to-from the
base. This is also the reason that GSM signals can be fairly poor when
in amongst buildings or wet trees, even though you may be close to the
base station you can find that your signal may be high, but the quality
of your conversation may have left little to be desired. As a result of
this, the high speeds of the trains mentioned in above threads can
directly affect the accuracy of which the base recieves the signal. 

Mick.

-- 
Mr Michael Kurkowski.
Email: simcard@tig.com.au
Snail Mail: P.O. Box 337 Glenroy, VIC 3046
Web: http://simcard.base.org  ICQ: 1459118
--------------------------------------------------
Thought for today: Due to the sale of the light at
 the end of the tunnel to the private sector, it 
  will only operate in the hours of 5pm til 9am.