But the phone only send a message to the base station
every few minutes, unless you're on a call, doesn't it?

I may be wrong with this, and your logic does make sense, but I thought the phone was essentially a passive receiver which occasionally reminded the network it was still there unless it's actually being used for communication.

But I'm not an expert, so am prepared to be proved wrong.
( K2k6 has a proper job these days, Thu 6 Aug 2009, 11:30, 1 reply)

I take it back...partly
The text message can be relayed over the network as part of the intra-network signalling comms without requiring extra bandwidth. It's only the initial transmission from the sender's phone and final relay to the receiver's phone that requires a separate message to go out.

So in that sense, it's free to the operators.1
( K2k6 has a proper job these days, Thu 6 Aug 2009, 11:38, closed)

yeah's
thats pretty much it its the final legs that costs them but it's something ridiculusly small like 0.001p per message sent out so theres a massive mark up on it
(NuffMuff fucks shrubbery, Thu 6 Aug 2009, 11:43, closed)