User Manual

6 Troubleshooting
Base Station User Guide 65
NMS Troubleshooting Tests – Troubleshooting Procedures
The following are trouble shooting procedures for cases where the measurements
differ from the expected levels. Note that the FAT results for the device are included
in the package.
Parameter Expected Value Possible Fault Correction
Downstream Received
Power
- 16 ± 3 dBmV
Fault in one of the
following: WMTS DS
card, Upconverter, PA,
splitters, cables and
connectors.
Call technician to
check test point and
compare with the
FAT results.
Downstream SNR ≥ 30 dB
Fault in one of the
following: WMTS DS
card, Upconverter, PA.
Call technician to
check test point and
compare with the
FAT results.
MMU Output Power
62±4 dBmV
Fault in one of the
following: LNAs,
Downconverter, WMTS
Hex US card, cables and
connectors.
Call technician to
check test point and
compare with the
FAT results.
Upstream Received SNR ≥ 22 dB
Fault in one of the
following: LNAs,
Downconverter, WMTS
Hex US card
Call technician to
check test point and
compare with the
FAT results.
Test Points Signal Verifications
The Base Station rack is pre-adjusted and tested before shipment. After the initial
operating process, all base station’s functions should operate properly, and no
adjustment is needed. Most functions can be tested using the MMU, via the NMS. The
MMU tests enable long-term local and remote tracking and monitoring of the system
performances.
The RF test points enable more in-depth tracking of the downstream and upstream
signal. The downstream test points are used for monitoring the signal level, as well as
the signal quality (spectrum re-growth and side lobes). The upstream test points are
used to check the upstream signal level, the SNR, and the Signal to External
Interference ratio. The tests you can run using the tests points are not required for
initial operation. They should be performed only if there is a significant difference
between the measured and expected results.
The following table describes the RF Test points and the related expected nominal
levels with the spectrum analyzer setting for these tests. For comparison, the table
includes also the FAT (Factory Accepted Test) expected results and related FAT
paragraph with the tests conditions. Note that for a real comparison you should follow
the full FAT procedure as described in the related paragraph.