Failure Of An Ms To Search The Network; Table 7-3 Meaning Of The State Of The Liu Leds (Uelp Not Used) - Huawei BTS3900 GSM Commissioning Manual

7 FAQs for BTS Commissioning
After the physical loopback test, set the E1/T1 at the DDF on the BTS side from physical
loopback to normal connection. Ensure that the connections are sound.

7.3 Failure of an MS to Search the Network

This describes the fault symptom and analyzes the cause of the failure of an MS to search the
network.
Fault Symptom
An MS fails to find the network.
Cause Analysis
The possible causes are as follows:
l
l
l
l
l
7-6

Table 7-3 Meaning of the state of the LIU LEDs (UELP not used)

If...
The LEDs are OFF
The LEDs are ON or ON for 0.125s and
OFF for 0.125s
(5) Reconnect the E1/T1 cable to the OUTSIDE port on the UELP and ensure that the
connection is proper.
(6) Reconnect the E1/T1 cable to the INSIDE port on the UELP and the E1/T1 port on
the GTMU, and ensure that the connection is proper.
CAUTION
Cell parameters such as CGI, BCCH, TA, and BSIC are improperly configured.
The MS does not support the frequency band of this base station.
The downlink signals are weak. Therefore, the MS is unable to locate the cell.
The downlink interference is strong. The MS is unable to locate the cell or receive the
correct downlink system information.
The cell radius is small.
NOTE
When the MS fails to find the network, pay attention to the output power of the local cell and the radio
network coverage.
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BTS3900(A) GSM
Commissioning Guide
Then...
The UELP is faulty.
a. Check whether the connection
between the UELP and the backplane
of the BBU is reliable.
b. Replace the UELP.
The UELP is functional, but the E1 link
on the BTS side is faulty.
Issue 02 (2009-04-20)