Telephone Line Band & Signal Spectrum - Canon FACSIMILE BASIC 2000 Service Manual

4. TELEPHONE LINE BAND & SIGNAL
SPECTRUM
Although the bandwidth of regular telephone lines is 300 to 3400 Hz, the
upper limit is 3000 Hz for submarine coaxial cables for international com-
munications. This is for the efficient use of high-cost cables.
Telephone line
frequency
characteristics
0 300
Tonal signals
G3 procedure signals
(binary signals)
(FSK)
G3 image signals
4800,2400bps
(PSK)
G3 image signals
9600,7200bps
(QAM)
Fig. A-12 Telephone Line Bandwidth and Signal Spectrum
1000 2000 3000 3400
1650 1850
1800
1700
1
2
3
4
Frequency
(Hz)
5
Frequency
(Hz)
6
Frequency
(Hz)
A
Frequency
(Hz)
çi
Frequency
(Hz)
A–19