OPU-1
UNIVERSAL POWER-LINE CARRIER SYSTEM TYPE OPU-1
GENERAL DESCRIPTION - Rev 7 (May 2019)
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1
INTRODUCTION
1.1
TRANSMISSION CAPACITY
The OPU-1 Universal Power-Line Carrier (PLC) terminal is outstanding in its high level of
modularity, allowing the transmission of all type of services through a high-voltage line.
It can be configured to transmit analog, digital or both analog and digital channels
simultaneously, including teleprotection.
When working with analog channels, the OPU-1 terminal can transmit one or two 4 kHz
standard channels in each direction. The effective band of each channel, from 300 Hz to
3850 Hz, can be used for the transmission of data at high speed, various VF telegraph
channels, teleprotection signals or for a speech-plus service.
When working with a digital channel, the OPU-1 terminal can support two different digital
modulation schemes (QAM or OFDM/OQAM). In general terms QAM is more suited for
long lines and medium transmission rates, while OFDM/OQAM is more suited for higher
transmission rates over short lines.
With the OFDM/OQAM digital modulation scheme, the OPU-1 terminal can support a
maximum transmission rate of 324 kbit/s in a bandwidth of 32 kHz, in each direction. A
transmission rate of 160 kbit/s in a bandwidth of 16 kHz, of 72 kbit/s in a bandwidth of
8 kHz, and of 32 kbit/s in a bandwidth of 4 kHz, in each direction, is also possible.
When working with a QAM digital channel, the OPU-1 terminal offers a transmission rate of
81 kbit/s, of which 79 kbit/s are available for user information, allowing various speech and
data channels to be multiplexed or, alternately, establish a channel of 64 kbit/s plus other
additional channels, up to a total of 15 kbit/s for signalling, telecontrol, etc. The multiplexing
of the different services, if desired, can be carried out by using an optional TDM internal
multiplexer that consists of up to three additional modules (speech and data ports). The
high-frequency transmission channel occupies a bandwidth of 16 kHz, in each direction.
Thanks to the use of a built-in echo canceller, the transmission and reception bands can be
superimposed, resulting in a total bandwidth of 16 kHz.
