High-Speed Transmission; V.8/V.34 Protocol - Canon FAX-L350 Service Manual

FAX-L350 Chapter 2: Technical Reference
7. NEW FUNCTION

7.1 High-speed Transmission

The image transmission time is reduced drastically compared with the previous models by the V.34 modem
(maximum transmission speed 33600 bps) recommended by ITU-T.

7.1.1 V.8/V.34 protocol

a) Outline
• The V.8 protocol is used as the startup protocol to move to V.34. The V.8 protocol enables connection
with fax machines, data modem and equipment using existing V-series modems. The V.34 modem
contains a modem circuit based on the previous recommendation to connect with the previous modems
and has upper compatibility.
• The actual data transmission speed is improved entirely on average by speeding the modulation method
and utilizing new techniques, such as the pre-emphasis technique
noise) ratio and the probing technique
operation according to the line condition.
• The V.8 protocol, V.34 pre-protocol and post-protocol use full-duplex transmission to speed the process-
ing.
• Fourteen image transmission speeds
33600, 31200, 28800, 26400, 24000, 21600, 19200, 16800, 14400, 12000, 9600, 7200, 4800, and 2400
bps
• The modulation speed (baud rate)
(required) or 2743, 2800, and 3429 symbols/sec (option). The data transmission speed can be set more
finely than the previous modems.
NOTE
*2
*3
are available:
*4
can be selected from among 2400, 3000, and 3200 symbols/sec
*1 The output level of a high-frequency zone with comparatively high noise is raised, and
then the transmission signal is sent.
*2 A tone signal known as a probing signal (L1 and L2) is output, and the receiving side
measures the characteristics of the line.
*3 The data signaling rate is recorded in the ITU-T standards manual. Image transmission
speed means the same as data signaling rate.
*4 The symbol rate is recorded in the ITU-T standards manual. Symbol rate means the
same as moderation speed and baud rate.
2743 symbol/sec cannot be used with this fax.
*1
for increasing the S/N (signal-to-
for measuring line characteristics and optimizing the modem
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