User Manual Part 2

Lynx.GX Installation and Management
Appendix G. Troubleshooting
This chapter provides information about:
▪ Changing Frequency Plans
▪ Counteracting and Evaluating Interference
▪ Troubleshooting data stream errors and interference
▪ Troubleshooting alarms
▪ Measuring radio function
▪ Troubleshooting radio management tools
▪ Repair policy
CHANGING FREQUENCY PLANS
The radio frequency selections are listed in “Channel Plans” on page 70. The near-end radio and the far-end
radio must correspond, for example, A1 and A2. All 1 frequency plans can be selected, when available, from
the radio model with the low-side RF unit, or the “ –xxL0” model. All 2 frequency plans can be selected, when
available, from the radio models with the high-side RF unit (the “–xxH0” model).
The frequency plans are configured in the Sys Cfg tab of the Web Interface.
COUNTERACTING AND EVALUATING INTERFERENCE
The recommended interference countermeasures available are:
▪ Short paths
▪ Narrow beam antennas (high gain)
▪ Frequency channel selection and orientation
▪ Antenna Polarization
▪ Transmit Power
▪ Equipment/Antenna Location
▪ Use of a Spectrum Analyzer to evaluate potential interference
Short Paths
The single most effective countermeasure against interference is to maintain a “short path” length. This can be
achieved by dividing long paths into multiple small paths by cascading hops. Intermediate repeaters can be
formed using back-to-back terminals and transmit output power reduced, if required.
By definition, “short path” is defined as a path where fades are extremely rare and signal levels vary by no more
than ±3 dB during fades. This distance varies with the RF frequency. Typically a “short path” is defined as any
path length shorter than 5 miles at 5.8 GHz.
Appendix G. Troubleshooting 93