Specifications

FibeAir 4800 Installation and Operation Guide Chapter 5 Diagnostics and Troubleshooting
FibeAir 4800 Installation and Operation Guide 5-5
and RX bytes for Ethernet). For the Air Interface, user defined thresholds data are
collected. Refer to Table 5-1 and Table 5-2.
Data is collected and selectively displayed based on three time intervals as selected
by the Interval radio buttons:
• Current (t=0)
• 15 minutes Intervals
• Daily.
The most important parameter is the UAS. This parameter counts the time the air
link was not providing any service. There are several potential reasons for this
situation; one of the sites has a power failure, high interference, maintenance
operation etc.
The next important parameter is the Radio BBER Threshold. This parameter counts
the seconds in which the radio performance is below a user specified threshold.
The threshold is measured in percent. The threshold can be set from 0.1% up to
50%.
For links with E1/T1 service the recommended value is 1% (Which is the system
default). Excellent TDM service, is expected below the 1% threshold, meaning that
for 1% threshold, the expected BBER value should be 0 if there are no problems
during the 15 min interval. When the BBER threshold increses some degraded
service might be noticed.
For links with Ethernet only service, 8% threshold is recommended and not 1%
(Which is the system default) meaning that for 8% threshold, the recommended
BBER value should be 0 if there are no problems during the 15 min interval. Since
FA4800 provides a loss less Ethernet service, there is throughput degradation in
case of interference. The degradation is proportional to the BBER.
Radio RSS Threshold can also be used to indicate problems in the radio channel.
After verifying the RSS according to the link budget calculator during the
installation (see installation manual). A value of -5dB from the current RSS is
recommended as a threshold.