DIMAT OPU-1 - Page 47

OPU-1
UNIVERSAL POWER-LINE CARRIER SYSTEM TYPE OPU-1
GENERAL DESCRIPTION - Rev 7 (May 2019)
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Supervision of data link quality
According to the G.821 standard
Pilot tone (analog channel)
Functions
➢ Automatic Gain Control.
➢ Telephone signalling.
➢ Signal-to-noise ratio measurement.
➢ Link synchronization.
➢ Service channel (data transmission).
Central frequency
150 Hz (virtual frequency)
Modulation
By frequency-shift keying of 30 Hz
Maximum rate
50 bit/s
Pilot tone (digital channel)
Functions
Automatic Gain Control
Internal clock (Master)
Frequency stability within specified
temperature and voltage ranges
1ppm
Ageing
<1ppm/year
Synchronization
➢ Analog channel: Synchronous or
Plesiochronous (non-synchronism).
➢ Digital channel (QAM): Master-Slave
Automatic Gain Control (AGC)
in analog channel
Dynamics
55 dB with 10% pilot modulation
Efficiency
20 dB input level variations cause variations
of less than 0.2 dB at the output
Automatic Gain Control (AGC)
range in digital channel
47 dB