, the PPM-350B optical power meter is different from common optical
power meters. Specifically, the PPM-350B has a downstream input optical port and an upstream
input optical port and can display the optical power of three wavelengths: 1310 nm, 1490 nm,
and 1550 nm.
shows the common measurement points.
Figure 4-3
Measurement points of the optical power in the GPON network
Maintenance engineers should also know related optical specifications on the ONT side, such
as the maximum output optical power of the 1310 nm wavelength, minimum input optical power
of the 1490 nm wavelength, and receiver sensitivity of the 1490 nm or 1550 nm wavelength.
lists the optical specifications on the ONT side.
Table 4-3
Optical specifications of optical ports on GPON ONTs
Parameter
Type
Wavelength
(nm)
Unit
Min.
Max.
Upstream data
1310
dBm
+0.5
+5
Downstream
data
1490
dBm
-28
-8
Downstream
CATV
1550
dBm
-8
+2
To use an optical power meter, do as follows:
1.
Connect optical fibers to optical ports correctly in upstream and downstream directions.
2.
Turn on the power supply.
3.
Choose the measurement unit (dB or dBm).
4.
Perform the measurement.
shows the measurement interface of the optical power meter.
4 Maintenance and Troubleshooting
EchoLife HG8240/HG8245/HG8247 GPON Terminal
Service Manual
4-8
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Issue 04 (2011-01-12)
