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Two LEDs indicate the presence of DC voltage on each MPT power output.
3.10.8 — Radio transmission features with MPT-HC/HC-HQAM/
MC/XP/XP-HQAM/9558HC
3.10.8.1 — Frequency agility
The Frequency Agility feature gives the operator the ability to set the frequency of a single
Transceiver within a chosen sub-band to select the RF working channel via MCT. This
provides benefits for spare parts, order processing and frequency co-ordination.
3.10.8.2 — Automatic transmit power control (ATPC)
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.
3.10.8.3 — Transmitted power control: RTPC function
MPR-e and MSS-1c User Manual 3DB19901EFAA Edition 01
Functional description
149
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