ZXG10 BS21 (V2.2) Compact Outdoor BTS for GSM Maintenance Manual
136
Confidential and Proprietary Information of ZTE CORPORATION
6.
Troubleshooting
i.
View the signal intensity of the MS. If the intensity is low, the
receiving level is too low. Follow the steps below to eliminate the
faults.
¾
Check whether the RF cable between the ETRM and the AEM is
connected normally. If not, please connect them again. Otherwise,
go on to the next step.
¾
Observe the level-1 alarm indicator of the SWR1 standing wave
ratio on the AEM panel. If it is on, check the standing wave ratio of
the jumper, master feeder and antenna from the combiner output
interface section by section until the reason why the standing wave
ratio is getting worse is found: Whether the connectors between
the set top hopper, master feeder and antenna are in poor contact
or the leakage from poor encapsulation. At last, consult Appendix A
to replace the faulty parts until the faults are eliminated. If the
alarm indicator is still off, proceed with the next step.
¾
View whether the orientation and the pitch angle are normal. If
abnormal, adjust the antenna, otherwise, proceed with the next
step.
¾
Measure the PA output power to confirm whether it is much lower
than the normal value (please refer to “Measuring Amplifier Output
Power” for its testing method). If the output power is abnormal,
adjust the power control. If still too low, replace the ETRM.
Otherwise, skip into Step 3.
ii.
View the measure report from BTS. If it is the uplink level
difference, follow the steps below to eliminate the fault.
¾
Check whether the wireless parameters are configured properly
from the background. Focus on checking the MS maximum
transmission power MSTXMAXCCH upon access in the cell wireless
parameters (Path: wireless resource configuration
Æ
cell
Æ
modify
Æ
wireless parameters) and the MS maximum transmission power
MSTXPWRMAX used for power control (Path: wireless resource
configuration
Æ
cell
Æ
changeover control parameter
Æ
other
parameters); In the GSM 900 network, set these two parameters
as 33 dBm while in the GSM 1800 network, they are set as 30 dBm;
If parameters are set correctly, go on to the next step;
¾
Check whether the RF cable between the combiner and the ETRM is
connected normally, if abnormal, please connect them again.
Otherwise, go on to the next step.
iii.
View whether clock alarms occur at the CMM, or go to the site to
view the CLK indicator of the CMM. If its green indicator is on, the
module is normal (the network synchronization is in locked status).
If the red indicator is on, replace the CMM. If the indicator is
normal, use LMT to view whether the frequency error the 13M clock
outputs is within the specified range.
iv.
If the clock is normal, check whether phase-locked loop alarms
occur at the ETRM. If yes, replace the ETRM. Otherwise, go on to
the next step.
