Note: Although the optical fiber link total carrier-to-noise ratio performance is primarily
determined by the laser transmitter’s performance, it simultaneously is affected by
many factors. For example, the amount of the laser power added to the optical
receiver, the quality of the optical receiver noise characteristic, the length of the
transmit optical fiber and so on, will cause transmission link total carrier-to-noise ratio
performance changes. Lower optical laser power, higher receiver OWN noise, longer
transmit optical fiber, are all factors that may increase or decrease the carrier-to-noise
ratio.
1
、
Optical receiver – as the received optical power decreases by each 1dB, CNR
will deteriorate by 1dB, and vice versa.
2
、
Theoretical analysis and experimental studies indicate that the optical receiver
received optical power decreases each 1dB, then the optical receiver’s detector
output RF signal level will decrease 2dB, and vice versa.
3
、
When the received optical power in the same circumstance, link loss is
determined by the fiber composition or the passive loss which will impact the
carrier-to-noise ratio of the link.
IV Operating method
1
、
Open box inspection
The low power return optical receiver produced by Maxcom undergoes strict
production checks, carefully packed before leaving the plant. There is an
operating manual and appendix in the packing case. After receiving the
equipment, the user should inspect the packing box. If there is damage, you
should notify the delivery service to indicate a possible claim. You should then
inspect the equipment to determine if it was damaged during the delivery, and
contact Maxcom as soon as possible.
2
、
Equipment installation
The MX4RR –LI reverse optical receiver is an indoor 1U rack structure with
natural ventilation cooling. The working environment temperature is 0
℃
~50
℃
,
the nominal power is AC 110/220V, 50/60Hz, power fuses is 1A, 20mm long.
Receiver’s optical input port is SC/ APC connector (FC/ APC optional), high
quality APC connector is recommended.
3
、
Energized Inspection
Necessary test tools should be used for set-up. Such as a digital multimeter, SC/
APC optical fiber jumper, optical power meter, RF signal level meter, spectrum
analyzer, etc.
The optical power transmitted from the reverse laser transmitter, to the reverse
optical receiver should be designed and set up to target the optical receiver input
power range. Before connecting the optical signals to the optical receiver, you should
use an optical power meter to verify the optical level, the level should not exceed
0dBm, between 0dBm~-20dBm is preferable.
