Automatic Transmit Power Control (Atpc); Transmitted Power Control: Rtpc Function; Power Monitoring - Alcatel-Lucent 9558HC User Manual

Functional description

Automatic transmit power control (ATPC)

Transmitted power control: RTPC function

Power monitoring

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The Automatic Transmit Power Control (ATPC) function automatically increases or
decreases the transmit output power upon request from the opposite terminal. The opposite
terminal constantly monitors the Receive Signal Level (RSL), receive signal quality, and
aggregate Bit Error Rate (BER) of the receive signal.
When ATPC is enabled, the transmit output will remain at its lowest level until a fade occurs
(or a receive circuit alarm is detected). When the change in RSL is detected at the receive end,
a command is sent to the transmit end to increase power in 1-dB steps to it's highest level.
After the fade is over, the receive end commands the transmit power to decrease in 1-dB steps
to the lowest level.
The ATPC range (high and low limits) is variable, determined by link distance, link location,
and link frequency. When ATPC Enabled is checked, the range values are shown in
parentheses (minimum - maximum) in the ATPC Range field.
When ATPC is disabled the transmit output will always operate at the power value set by the
MCT.
The set point of the ATPC regulation (ATPC RSL threshold) must be chosen considering the
link budget. For example if the set point is too high, the remote transmitter will permanently
remain at maximum power. It is recommended to choose a value at least 15 dB above the 10-
6 BER threshold.
The capability to adjust the transmitted power in a static and fixed way (RTPC = Remote
Transmit Power Control) has been introduced for those countries where, due to internal rules,
the ATPC function is not accepted or for those hops in which due to the short length and
interface problems, a fixed reduced transmitted power is preferred. The range of the possible
attenuation depends on the frequency band involved. The setting of the transmitted power can
be done locally through MCT.
The Output power is band- and modulation-dependent.
The MPT-HC V2/MPT-XP/9558HC incorporates a detector for Tx power measurement. It is
used to provide measurement of forward power as a performance parameter and to provide a
calibration input for transmitter operation over temperature and output range.
MPR-e