7.3 Failure of an MS to Search the Network. Huawei Technologies QISGRFU-1900

7 FAQs for BTS Commissioning

BTS3900(A) GSM

Commissioning Guide

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

If...

The LEDs are OFF

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.

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

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 l l l l

The possible causes are as follows: l

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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Copyright © Huawei Technologies Co., Ltd.

Issue 02 (2009-04-20)