Steve Terry wrote:
"Rupert wrote in message
...
Steve Terry wrote:
snip

Well done. How about the actual operational needs.
To pick a simple example. Tetra works on the TGV, GSM doesn't

GSM could, GSM is now possible on airliners using cells on the aircraft
linked up to satellite or down to ground stations, and GSM is regularly
used on sea going Ferries using similar systems.

A more practical example is when i was in Hong Kong in 2002 i was using
GSM all over their MTR underground railway.
Obviously if the public have GSM down there, so did the staff and any
emergency services.

Translation: Steve Terry doesn't understand the issues. Think why I chose
TGV especially, rather than another line. Umm. Perhaps it is to do with
the speed of the handset relative to the basestation.


Of course i understand the speed limitations of GSM, that's why i pointed
out
the use of GSM on airliners using onboard cells.


You have to have the cells onboard and onboard cells are still sparse.


Maybe you haven't noticed but airliners travel faster than the TGV

So which do you think a member of the emergency services would
use to make a call on such an airliner, GSM or their Tetra?

Well, the users I represented would use their Airwave handsets to the
fixed wing following behind. And, because Tetra has been designed in
this way, they would be able to have a talk group with people ahead and
behind the plane. Oh, and could have quick call set up. Oh and do this
even in the event of riot and civil commotion. Oh and talk directly with
other agencies. And quite a lot else besides which I won't go into here
coz it won't help