Chapter 6 - Troubleshooting
Confidential and Proprietary Information of ZTE CORPORATION 137
v.
Correctly set the E1 DIP switch of the CMM (For coaxial cables, set
it as 75
Ω
)
vi.
Check whether co-channel interference occurs. If yes, please adjust
the frequency.
7.
Precautions
None.
Troubleshooting in BS
Maintenance Stage
Shrinkage of BS Coverage
1.
Symptom
The shrinkage of BS coverage somewhat results in the blind area
within a certain range: Calls can not be made where the calls can be
made formerly and poor signal quality or no signals occur where the
signal quality is good originally, and call drops increase obviously.
2.
Source
Find the fault when making a phone call.
3.
Related parts
Antenna feeder system, parameter settings, ETRM modules and
environment influence.
4.
Analysis and locating
Many technical indexes such as system frequency, sensitivity and
power or geography and electromagnetic environment may directly
influence the coverage of the BS. Normally, the technical indexes of
the system is comparatively stable. The BS constructed in an
unfavorable environment, maintained improperly or its poor quality
may influence its coverage.
The following factors will influence the coverage of the BS: Too low
power amplifier output, decreased receiver sensitivity, inclined azimuth
angle, changed antenna pitch angle, changed gain and height, feeder
cable or combiner loss, changed working frequency and transmission
environment and diversity reception.
