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Chapter 6 - Troubleshooting
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6.
Troubleshooting
i.
Check whether the level threshold of the RACH receiving signal has
changed. If the threshold is much greater than before, it may
reduce the BS coverage.
ii.
Check whether there exists strong interference, which will reduce
the receiving sensitivity and coverage of BS.
iii.
Check whether the loss from the leakage of RF signal is caused by
the improper RF cable connection between the ETRM and the AEM.
iv.
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, main feeder and antenna from the AEM outlet section
by section until the reason why the standing wave ratio is getting
worse is found. The connectors between the set bottom jumper,
main feeder and antenna not contacted properly or feeder cable
leakage will reduce the transmission power to influence coverage.
At last, refer to Appendix A and replace the faulty parts until the
fault is eliminated.
v.
Check if the output power of PA has decreased. If abnormal, adjust
the power control. If still too low, replace the ETRM.
vi.
Check whether other antennas or obstacles exist around the
antenna. If yes, adjust the azimuth angle and height of the antenna
in time to lessen the influence.
vii.
Check whether the azimuth angle and pitch angle of the antenna
have changed since the deviation of them will cause smaller BS
coverage. Please adjust them in time after confirming the fault.
viii.
Use the power meter to check whether the lower transmission
power of the antenna is caused by the negative leakage of the
directional antenna. If yes, please replace the antenna in time.
7.
Precautions
Consider the following cases if the BS coverage is found to be poorer
during BS expansion.
i.
Whether different types of couplers are used since if the type or
number of them is different, the generated attenuation will also be
different.
ii.
Check whether the new antenna is installed as required, such as
azimuth angle and inclination angle, mounting height and whether
the coverage of the main antenna and the diversity is in
consistency, deviation from which may result in unstable coverage
effect when subscribers occupy different antennas.
iii.
Check whether the receiving sensitivity of BS is normal.