Search in: Word
Vietnamese keyboard: Off
Virtual keyboard: Show
Computing (FOLDOC) dictionary
Jump to user comments
communications, protocol A serial line protocol supported
by some modems. Uses symbol rates of 2400, 2800, 3000,
@#3200 and 3429 and up to 28800 baud.
V.34 modems will also support V.FC if the manufacturer
currently supports V.FC.
The first V.FC modems were shipped in November 1993 and there
have been many thousands sold. There will probably be in
excess of a million V.FC modems installed by the end of 1994.
V.FC was intended to take some of the techniques being
proposed for V.34 and put them into a real modem that people
could use. This also gave a lot of people the opportunity to
try out 28.8 kilobit per second operation for the first time.
There was never any intention from Hayes or Rockwell (who
worked together for two years on V.FC) that V.FC would be
compatible with V.34 - even if they had wanted it, others
would have made sure it didn't happen! In fact, they made the
start-up deliberately different from V.34 so that it would be
easy to distinguish between the two and easier to make
dual-mode V.FC/V.34 modems.
V.FC is quite different from V.34. Most of the
signal-processing algorithms, whilst based on the same
theory, are implemented in different ways. V.34 has some
extra things like a secondary channel and a special mode for
28.8 kilobit per second fax.
The Rockwell V.FC implementation uses a single-chip
mask-programmed DSP for all the signal processing functions.
You can also buy a modem controller chip from Rockwell to go
with it which implements AT commands, error-control and
compression. Hayes made their own controller using the
Motorola 68302 processor. When it comes to an upgrade
from V.FC to V.34 you have to have a new, masked DSP chip and
new controller firmware to implement all the V.34-specific
features. This means that Rockwell-DSP based modems must be
returned to the manufacturer for upgrade. Upgraded modems
will talk to either V.FC or V.34 modems.
Related search result for "V.FC"
Comments and discussion on the word "V.FC"