User's Guide
Table Of Contents
- User Guide
- Contents
- Preface
- 1 About this Guide
- 2 Overview
- 3 RU Hardware Feature
- 3.1 System Configuration
- 3.2 RU Specifications
- 3.3 Environment Specification
- 3.4 RU Downlink/Uplink Default Parameters
- 3.5 Antenna Configuration
- 3.6 Carrier Configuration
- 3.7 Block Diagram
- 3.8 External Interface
- 3.9 TX Control Function
- 3.10 Performance Requirement
- 3.11 Mechanical Design and Other Options
- 4 Ordering Information
- 5 Installation
- 6 Operations
- 7 Maintenance and Trouble Clearing
- 8 Removal
- A References
- B ZTP Overview
- C Optical Connector Cleaning
- D Glossary
- Index
3.9
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 at least by 1 dB steps for each band and for each TX port (controllable range is 10 dB).
Cold Start
When the system temperature at startup is −40 to −20 ℃, the system reports to the EM S as a Cold Start state
(refer to
M aintenance and Trouble Clearing). RF transmission is not performed 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 EM S.
TX Power Reduction
The RU supports the TX power reduction at switching to battery backup at the cell site. The TX power reduction
is configured by DL Gain controlling (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
battery backup automatically by DL Gain controlling from host system. In case of the power source is restored
after power loss, the RU resume normal operation at the condition before power loss automatically by 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
In order to reduce power consumption, the RU controls the drain voltage of the power amp in accordance with
the transmission mode. The drain voltage is switched according to the transmission output power of each band.
The transmission output power of each band is checked by the DL Gain value in the M-plane "TX-Array-Carrier"
message.
RU Hardware Feature
TX Control Function
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Release 1.0 · Issue 1, March 2021
Fujitsu and Fujitsu Customer Use Only