If you have on board internet access you will surely be aware of the
fact that lots of useless bits and bytes are being transmitted, and
that they come at a cost.

There's a nice and detailed article in Digital Ship's newsletter
looking at all the various possibilities for compression and
prevention techniques. Furthermore it discusses some (future)
developments of internet acces via satellite.

If you're interested, I've posted an abstract he
http://www.panbo.com/yae/archives/000458.html

Yme
http://www.panbo.com/yae/

in terms of payload per unit bandwidth,
UUCP moving email or netnews batches is
still one of the most efficient encodings
available. with "G-protocol spoofing"
enabled on a Telebit Trailblazer, you can
get more useful payloads bits/second over
the most eggregious circuits than any other
scheme I know about. hmm - it's interesting
to contemplate a Trailblazer running over an HF
connection. I suspect it doesn't retrain often
enough, but it is the first widely-deployed
implementation of OFDM (orthogonal Frequency
Divison Multiplexing) and for it's day, it
was a stunning achievement. In fact, it took
a long time for "ITU Standard" dialup modems
to come within lightyears of the TB's performance.

-mo