Troubleshooting Using The Usi Rsl Screens - Alcatel MDR-8000 User Manual

Troubleshooting Burst Errors
5.5.2.1
Burst errors are defined as multiple errors in a very short time. Burst errors can be caused
by many things, including loose connections on cable or waveguide at either end of the hop.
A "popping" oscillator can cause burst type errors. Burst errors can be identified by a high
number of Errors and low number of Error Seconds on the Performance screens. The
most probable cause of burst errors is a loose connection. Check/repair all shelf and exter-
nal cables and check all waveguide connections The next most probable cause is the crystal
on the crystal oscillator subboard at either end of the hop.If the radio has both A and B
XMTRS and RCVRS and both A and B are indicating burst errors, the fault is at the XMT
end of the hop. If only A is equipped and indicates burst errors, remove and replace the
crystal oscillator subboard on the on-line RCVR.
Troubleshooting Dribbling Errors
5.5.2.2
Dribbling errors are defined as small number of errors over long period of time (no frame
errors). Dribbling errors can be caused by a path problem, such as interference or fading,
or by a hardware problem such as a XMTR or PA that is being over driven, or high phase
noise in the XMTR or RCVR oscillator. Dribbling errors can be identified by observing the
and fields on the radio Performance screen. A rule of thumb of less
Errors Error Seconds
than five to one identifies the fault as dribbling errors. Try isolating
Errors Error Second
the transmitter by switching transmitters in a protected system. You can further isolate a
transmitter by changing output levels using ATPC and or dropping the output power out of
the XMTR to the PA by one or two dB.

Troubleshooting Using the USI RSL Screens

5.5.3
The USI RSL screens can be helpful in isolating an alarm due to a path problem, such as
fading, or an equipment failure. If for example there is an intermittent A-side
Loss of
alarm displayed on the Export list of alarms (available by clicking on the
Frame Export
button on the bottom toolbar on the RSL screen) and the A-side trace on the RSL screen
does not indicate a fade or low RSL, the fault is most probably in the equipment.
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