ZXG10 BS21 (V2.2) Compact Outdoor BTS for GSM Maintenance Manual
130
Confidential and Proprietary Information of ZTE CORPORATION
Troubleshooting at BS
Commissioning Stage
BS Works Normally but Mobile Phone Has
no Signals or Cannot Access Network
1.
Symptom
The mobile station has no signals, displaying “No network” or nothing,
but BS is in good conditions (no alarms).
2.
Source
Find the fault during the dialing test.
3.
Related parts
OMCR parameter setting, transmission equipment, antenna feeder
system and ETRM modules.
4.
Fault analyzing and locating
i.
Trace the Abis interface message to see whether there are channel
request messages. If no channel request messages occur in the cell,
the fault occurs at the network side, otherwise the problem is with
the MS.
ii.
Faults occurring at the network side may be caused by the
following factors.
¾
LAC and cell code at the MSS side are not configured consistently
with those at the BSS side.
¾
Wireless parameters are not configured properly.
¾
The hardware faults of BS such as antenna feeder system fault,
network synchronization not being in locked status and frequency
deviation occur on the clock, or ETRM fault.
¾
Transmission faults: Faults but no alarms occur to the transmission
(such as HDSL), unidirectional bit error occurs to the transmission,
bad grounding and other non-physical interruption faults. In the
ZXG10-BSS (V2) system, if BSC receives the signals from BTS but
BTS does not receive the signals from BSC, OMCR will indicate that
the transmission is normal (judged by whether BSC receives the
signal).
iii.
Faults occurring at the MS may be caused by the following factors:
¾
The MS is not located at the proper place. The quality of the signal
is too poor or the level is too low.
¾
Deficient MS battery capacity causes its receiving capability to
decrease.
