9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. V-2-7
For a remote-mounted ODU, check its antenna feeder.
• New path obstruction
Where all other parameters check as normal, and the path has potential for it to
be obstructed by construction works, view/survey the path for possible new
obstructions.
• Interference from other signal sources
Interference usually affects traffic in just one direction. Unlike other path
problems, RSL is not affected. If suspected, check for new link installations at
the same site or in the same geographical area. Ultimately a spectrum analyzer
may have to be used to confirm interference, which is not an easy task given
the need to connect directly to the antenna port, after removing the ODU.
Path Problems on a New Link
For a new link, potential problems can extend to also include:
• Incorrect antenna alignment
One or both antennas incorrectly aligned. For an alignment procedure, refer to
Volume III, Chapter 5.
• Mismatching antenna polarizations
Given a typical polarization discrimination of 30 dB, for most links a
mismatched polarization setting means it would not be possible to capture a
signal to begin the antenna alignment process.
• Incorrect path calculations
If the RSLs are too low or too high, antenna alignment is correct, and Tx
power settings are correct, check the path calculations used to determine the
link performance. A good calculation match is +/- 2 dB. Disagreements in
excess of 3 dB should be investigated.
• Reflections
Reflection (path cancellation) problems may not have been picked up at the
path planning stage, particularly if the survey was a simple line-of-sight. If
suspected, resurvey the path.
Troubleshooting Configuration Problems
Configuration problems should only occur during the set up of a new link, or
reconfiguration of an existing link. The more common problems may be broadly
categorized as:
• General compatibility problems
The two alarms that may activate are Configuration Not Supported, and
SW/HW Incompatible:
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