Aau Ret System - Huawei AAU3902 Hardware Description

AAU3902
Hardware Description
Item

2.5 AAU RET System

The remote electrical tilt (RET) system of an AAU consists of the remote control unit (RCU),
motor, gearing, and phase shifter. In the RET system, the RCU is used to remotely adjust the
downtilts of AU beams.
RET Function
After a remote control unit (RCU) receives the control signals from the base station, it drives
the stepper motor. The stepper motor drives the adjustable phase shifter in the AU to adjust
downtilts of the AU. In this way, remote electrical tilt (RET) is achieved.
RCU RET consists of the following:
l
l
The following figure shows the logical structure of RCU internal control.
Issue 06 (2014-07-30)
Silkscre Color
en
CPRI1 Red or
green
Internal control: Signals are received through the CPRI ports on an MU.
External control: Signals are received through AISG ports at the bottom of an AU.
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Status Description
Blinking red The CPRI link is out of lock. The
(on for 1s and possible cause is that clocks of two
off for 1s) modes are not synchronized or the data
rate negotiation over CPRI ports fails.
You are advised to check the system
configuration to locate the cause.
Steady off The SFP module is not properly
installed, or the optical module is
powered off.
Steady green The CPRI link is functioning properly.
Steady red An optical module fails to receive or
transmit signals because the optical
module is faulty or the fiber optic cable
is broken.
Blinking red The CPRI link is out of lock. The
(on for 1s and possible cause is that clocks of two
off for 1s) modes are not synchronized or the data
rate negotiation over CPRI ports fails.
You are advised to check the system
configuration to locate the cause.
Steady off The SFP module is not properly
installed, or the optical module is
powered off.
2 AAU Introduction
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