OLT SFP

Hello, friend!

The following table lists the differences between PON optical modules.

Type	One-fiber bidirectional optical module, class B+	One-fiber bidirectional optical module, class C+	One-fiber bidirectional optical module, class C++
Minimum Output Optical Power	1.5 dBm	3 dBm	6 dBm
Maximum Output Optical Power	5 dBm	7 dBm	10 dBm
Maximum Receiver Sensitivity	-28 dBm	-32 dBm	-35 dBm
Overload Optical Power	-8 dBm	-12 dBm	-15 dBm

The optical power of an optical module is affected by the following factors:

1. Wavelength

2. Transmission distance

3. Rate

4. Mode

Thanks!

nice

Thank you.
I know this tabele. But I don not understand these factors.
Wavelength is same, 1490nm for DS. Rate for GPON PORT is 2.5/1.25Gps.
I measure optical power for difference distance, 1490nm, 2.5/1.25Gbps, FTTH but optical power is same, about 4dBm.
What is mode? Is FTTH mode?

Hello, friend!

Mode refers to the single-mode or multi-mode optical module.

Optical fibers and optical modules must be used in pairs. That is, single-mode optical fibers are used for single-mode optical modules, and multi-mode optical fibers are used for multi-mode optical modules.

Thanks!

I do not understand. All fibers on GPON ports are single-mode fibers.
Multi-mode fibers are on upsteam ports.
When can I use multi-mode fiber on GPON ports (for downstream)?

And main question. I have constant factors for FTTH - wavelengh 1490nm (this is only wavelenght for DS), rate for GPON 2.5/1.25Gps (standard rate for GPON), mode single-mode fiber. Transmission distance is about 100m to 40km. But I measure for all these distance about 4-5dBm. I do not see defference.