Figure 7-27 Physical Loopback Of The E1/T1 Cable At The Ddf - Huawei 3900 Series Commissioning Manual

7 Commissioning the MBTS by Using Local Maintenance
Terminal and M2000
If ...
The UELP is configured
The UELP is not configured
Step 5 At the DDF on the BTS side, check whether the connectors of the E1/T1 link on which the
communication is abnormal are properly soldered. Poor jointing may cause poor E1/T1
connection.
Step 6 Perform a physical loopback test on the E1/T1 cable where the communication is abnormal.
Check whether the transmission of the E1/T1 cable is normal on the BTS side.
1.
2.
7-30
For a pair of E1s/T1s connecting the BTS and BSC through the DDF, port A is connected
to port C, and port B is connected to port D. In the loopback test, disconnect port A from
port C, and port B from port D, and then connect port A to port B, as shown in
7-27. In this way, the TX end and RX end of the E1/T1 cable are connected and the physical
loopback is formed on the BTS side.

Figure 7-27 Physical loopback of the E1/T1 cable at the DDF

Check the status of the LIU LEDs on the panel of the GTMU.
If ...
The LEDs are off.
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
3900 Series Multi-Mode Base Station
Then ...
Check the connection between the E1/T1 cable and
l
the OUTSIDE port on the panel of the UELP.
Check the connection between the E1 surge
l
protection transfer cable and the INSIDE port on the
panel of the UELP.
Check the connection between the E1 surge
l
protection transfer cable and the E1/T1 port on the
panel of the GTMU.
Check the connection between the E1/T1 cable and the
E1/T1 port on the panel of the GTMU.
Then ...
The E1/T1 connections are normal on the
BTS side. The problem may be the abnormal
connection between the BTS and the BSC or
the abnormal connection on the BSC side.
In this case, end the check, and contact the
technical support engineer on the BSC side
to clear the fault.
Commissioning Guide
Figure
Issue 02 (2010-07-30)