Electronic pulses that are transmitted, um, analoguely.
Yes, the scan of the fax is digital, and so is the print. But you
can't just pass off the transport mechanism as unimportant.
Fax machines connect directly to a(n analogue) phone line. Surely for
something to be classified as a fax it must be able to be accepted by
a fax machine? That being the case, a fax cannot be sent as
all-digital signals. Anything that is all-digital cannot be a fax.
You can make systems which behave similarly to faxes, but if they
can't be accepted by a fax machine they cannot be a fax.
Gareth
But that is what i said...even if you send fax from your PC through ISDN,
and second party receives it on fax machine, then it is converted to analog
signal, but in phone central, exactly where your ISDN line ends and
receiver's analog line starts. However, if receiver side also has ISDN and
fax machine, then this conversion is made in ISDN 'modem' just before it's
sent into fax machine. Who say that those faxes can't be accepted by a fax
machine? Sure they can, that's why they are still called FAXes. Although i
agree with you that this is an extension of fax principle itself, but still
as long it's exactly same principle and standard, it should still be called
fax. But if you ask me, i think that faxes are dissapearing anyway -
replacing by email.
You should know that analog to digital and vice versa converters were built
into fax machines only because at the time fax was invendted there were no
ISDN or any other digital transporting system, there was only analog phone
line, so this A/D and D/A were necesarry. If nowadays a fax for ISDN
connection would be on market, it wouldn't have ANY those converters
built-in. It's stupid to convert to analog and back to digital, if this is
not strictly necessary, since with it you loose quality. That's why this
conversion is made only if it must be done.
All i can say is that i sent many faxes from my PC via ISDN 'modem'
succesfully to other's party analog fax machine and noone so far knew that
this was created with PC and not sent by fax machine. All said that they
received my FAX, not email, so...
And this discussion can go on and on and on.... right?