Chapter 3
Fault Locating Methods
Table of Contents
3.1 Performing the Loopback Test
This procedure describes how to perform the loopback test.
Loopback is the process of an NE's transmitting a signal from its transmit port and
receiving the signal from its receive port. The loopback test helps detect the transmission
link problems.
Through the loopback operation, maintenance personnel can locate NE faults along the
communication link section by section. It helps check the operating status of each node
and the transmission link, and rapidly locates the faulty NEs and faulty boards, which
facilitates equipment commissioning and debugging.
In the NR8000 Series WEB LMT system, users can set radio link loopbacks (including
modulation/demodulation loopback and IF loopback), Time Division Multiplexing (
)
loopback, and Ethernet loopback.
Radio Link Loopback
Radio link loopback helps check whether the E1 service is operating properly.
Note:
The Ethernet service will be interrupted when the radio link loopback test is being
implemented.
The following describes the radio link loopback test procedure:
1.
Connect the device to an error bit tester.
2.
Log in to the WEB LMT system, In the left navigation tree, select
Maintenance > Radio
Port
. The radio link loopback setting pane is displayed on the right, see
.
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