Tx Control Function - Fujitsu 5GRUDB3 User Manual

RU Hardware Feature

TX Control Function

2.8
TX Control Function
Tx Power Control
The output power of the RU is set and controlled remotely via M-plane on ORAN interface. The output power of
the RU is controlled by 1 dB steps for each band and for each TX port (the controllable range is 10dB from the
maximum TX power for a single carrier).
Cold Start
When the system temperature at startup is −40 to −20 ℃, the system reports to the EMS as a Cold Start state
(refer to RU Alarms). RF transmission is not operating and power amp is set to on for warmup.
The temperature is monitored from the start of the device, and the Cold start state is released when the
temperature reaches −20 ℃ and reported to the EMS.
TX Power Reduction
The RU supports the TX power reduction on switching to battery backup at the cell site. The TX power reduction
is configured by DL Gain control (controllable range is 3 dB) for each band via M-plane message.
When the power source is restored from battery backup, the RU resume normal operation before switching to
battery backup automatically by DL Gain controlling from host system.
In case the power source is restored after power loss, the RU resumes normal operation at the condition before
power loss automatically as well as any other settings, for example, frequency and output power via M-plane
control from host system.
Transmission Blanking
The RU supports transmission blanking by PA on/off control for each RF port via C-plane control from host
system.
In case of warmup status, for example, cold start, PA on is set without transmission output regardless of C-plane
control from host system.
Drain Voltage Control
Dual-band RU has a transmit power of 80 W/Port and has two transmit modes, depending on the transmit power
of each band.
1. n70 + n66: 20 W + 60 W
2. n70 + n66: 40 W + 40 W
·
Issue 1.1, May 2021
Release 1.0
61
Fujitsu and Fujitsu Customer Use Only