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.
In the FTTx scenario, from CO/headend to the user side there are two points:
Optical distribution point, and
Optical access point,
and tree segments:
Feeder cable,
Distribution cable, and
Drop cable.
In the next figure, we can see all of these elements.
Figure 1. ODN
A feeder optical cable is an optical cable with a large number of fibers, e.g. 48F, 96F, 120F, 144F, etc. It is located between the CO/headend and optical distribution point. From that point (outdoor cabinet or optical closure) the network is further branched and distributed to users. This segment of the network can be realized aerial, underground, directly buried, underwater, or combined. It is generally recommended to be an underground way of installation.
Distribution optical cable is an optical cable of a smaller capacity than feeder optical cable. These are usually 24F, 12F, or smaller optical cables. The distribution of optical cable is located between optical distribution point (outdoor cabinet or optical closure) and optical access point (outdoor cabinet, optical box, optical closure, etc). This segment of the network can be realized aerial, underground, directly buried, or combined. It is generally recommended to be an underground way of installation.
Drop optical cable is the last segment of the ODN network. It is located from the optical access point to the ONU device. These are the cables with the least number of optical fibers. These are usually 1F, 2F, or 4F fiber optic cables. There are different variants of this optical cable. Realization can be an aerial, underground, or direct burial. An underground installation is recommended.
These are typical solutions for FTTx. With the POL solution, the situation is a little different. The entire system, ie ODN is in or near the facility (up to a maximum of several km). It can contain all ODN elements or some parts depending on the size of the campus network.
This is the end of this article. I will explain this topic in the next article >> ODN Engineering and Maintenance (3).
Thank you!
Reference:
HCIA-Access, ver. 2.5, Huawei Access Certification Training
