Chapter 5. Antenna Alignment
Vol. III-5-2 Alcatel-Lucent
Signal Measurement
Two receive signal-strength indicators are provided to assist antenna alignment,
RSL in the CT Performance screen, and the RSSI voltage at the BNC connector
on the ODU. Refer to:
• Using RSL Data
• Using the RSSI Voltage at the ODU
• RSL Measurement Guidelines
Using RSL Data
As CT is accessed via connection to the INU or IDU, a separate means of
communication such as two-way radio or cell phone is required between the CT
operator and the person at the antenna.
To align using RSL:
1. Monitor RSL in the CT Performance screen.
2. Set antenna alignment for maximum RSL.
3. Repeat for the far end of the link.
4. Compare actual RSLs with the expected RSLs from the link installation
datapack. RSL measurement accuracies for ODU 300ep and ODU 300ep are:
± 2 dB for levels -40 to -70 dBm, over a temperature range of 0 to +35
o
C.
± 4 dB for levels -25 to -85 dBm, over an extended -33 to +55
o
C range.
Using the RSSI Voltage at the ODU
A voltmeter, such as a multimeter, is used to measure RSSI voltage at the BNC
connector on the ODU. A suitable BNC to banana-plug connecting cable is
available as an optional ODU accessory.
To align using the RSSI voltage at the ODU:
1. Connect the voltmeter to the BNC connector. Center pin is positive. Use a low
voltage range for best resolution, nominally 2.5 Vdc FSD.
2. Adjust antenna alignment until the voltmeter reading is at minimum value.
3. Repeat for the far end of the link.
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