Hello, everyone!
Today, I want to continue to explain a new topic – ODN engineering and maintenance. Now, I will explain the main elements of the ODN network. Today, it is an optical splitter.
One of the most important elements of all PON systems is the optical splitter. It is usually 1: N, where one is the input port and N output ports, but there are also 2: N optical splitters (two input ports and N output ports). N can be 2, 4, 8, 16, 32, 64, …
Optical splitters allow you to connect a large number of ONU devices to OLT. Typically 32 or 64 is the splitting ratio, and the theoretical max for GPON is 128. It is recommended that there be one or two splitting levels.
Optical splitters bring the greatest attenuation to the system. The following table shows the attenuation values.
Splitter ratio |
Average loss (dB) |
1:2 |
≤ 3.5 |
1:4 |
≤ 7 |
1:8 |
≤ 10.5 |
1:16 |
≤ 14 |
1:32 |
≤ 17.5 |
1:64 |
≤ 21 |
The attenuation of optical splitters can also be calculated using the following formula:
as(dB) = 10*log(1/N), N = 2, 4, 8, 16, 32 and 64.
Optical splitters can be with or without optical connectors. There are different variants of optical splitters, it depends on the application. We can see this in the pictures above. These are the following optical splitters:
mini splitter. The smallest optical splitter can be with or without optical connectors. It takes up little space and is therefore widely used. The disadvantage is the high possibility of damage.
box-shaped splitter unit. These are optical splitters with extra protection compared to mini splitters. There is a plastic case and a 2 or 3 mm jacket. They take up more space but are less sensitive. They have a wide application.
rack-mounted splitter unit. Optical splitters are installed in the 19-inch rack-mounted splitter unit. They are most commonly used in headends.
slotted splitter unit. The complete optical splitter is housed in a metal housing. There are only input and output optical connectors on the case. They enable fast and safe installation.
tray splitter unit. Complete optical splitters are housed in a metal housing. Quick and easy installation is possible. They are used in ODFs and FTDs.
wall-mounted splitter unit. The optical splitter is housed in a box, allowing for quick, easy installation in indoor and outdoor applications.
This is the end of this article. I will explain this topic in the next article >> ODN Engineering and Maintenance (7).
Thank you!
