Aviat Networks ECLIPSE EDGE, User Manual

Page: 167 / 274

260-668080-001 Rev 002 March 2013 5
Eclipse Edge User Manual
Measuring the Fade Margin for Edge
The Portal screens used are:
• Configuration > Plug-ins > Link for Tx power and ATPC control.
• Diagnostics > Performance > Link for RSL and G.826 error data.
• Diagnostics > System/Controls > Link to lock a
protected link to one side.
To measure the fade margin:
1. Ensure ATPC is not selected, and for a protected link, force (lock) the link to one
side.
2. Note the Tx power setting, and the detected Tx power reading at one end of the link.
3. Note the RSL at the other end of the link.
4. Prepare to monitor errored seconds in the receive-end Performance screen.
Alternatively, use a BER test on a looped tributary.
5. Reduce the Tx power in steps until the receiver threshold is reached as indicated by
the onset of errored seconds.
6. The fade margin is the difference in Tx power between the normal power and the
power at Rx threshold.
7. At threshold, the indicated receiver RSL in dBm can also be compared with the
receiver datasheet specifications as a direct check of receiver threshold.
Lower Than Expected Fade Margin Situation for Edge
If the measured fade margin is significantly less than the expected margin, reasons
can include:
• Accuracy of measurement not taken into account. For Eclipse Edge, the margin for
error can be up to 3 to 4 dB, given the limitations of software-set power control, RSL
measurement and G.826 error capture. Similarly, the margin for error for a receive
threshold check can also be up to 4 dB given the limitations of internal RSL and BER
alarm measurement. Measurement accuracy may be improved with the use of an
external BER tester.
• Equipment performance outside specification.
• Path loss higher than expected.
• Antenna misalignment.
• Interference from other transmitters.
For more information on fade margin, refer to Commissioning Tests and to
Diagnostic Tools in Aviat Networks’
Best Practices Guide .
Protection Switching for Edge
This topic provides test procedures for Eclipse Edge links configured for Dual ODU
protection.
Refer to:
•
Switch Operation Test Measurement for Edge on page 6
•
Link Protection Logic for Edge on page 6