[TeMPOraL]

Thanks for the actual number. It seems though that 172 000 refers to simultaneous voice users. I was thinking about their data services - planes could send short bursts of location data (couple hundred bytes at most) every minute or three.

I agree it's not a trivial problem to solve, but it looks solvable.

[mcculley]

I agree that this seems easily solvable. We use SPOT Trace (http://findmespot.com/en/index.php?cid=128) units on offshore tug boats, as do many in the shipping industry. These periodically send their GPS location back via Globalstar. It seems to me that if a passenger jet can be approved to install satellite TV receivers, it could be approved for these.