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 optical cable and optical fibers.
Fiber optic cable is the most important element of the ODN segment. It is used to connect and communicate between OLT and ONUs. There are a large number of different optical cables, and the task of each optical cable is to protect the optical fibers. Fiber optic cables may contain a different number of fibers, depending on the application.
In general, all fiber optic cables are divided into two major groups: loose tube optical cables and tight buffer optical cables. Fiber optics are divided into two major groups: SM - singlemode and MM - multimode. SM optical fibers are only used in the ODN segment.
Fiber optic is used as a portable medium. It consists of a core and a cladding. Signal transmission is exclusively through the core. Fiber optics are always with a primary buffer coating.
SM optical fibers have a core diameter of about 8 - 10 μm and a cladding diameter of about 125 μm. MM optical fibers have a core diameter of 62.5 or 50 μm and a cladding diameter of about 125 μm. SM transmits one mode, while MM transmits several modes.
A pig tail is an optical fiber that has an optical connector at one end. Otherwise, the optical fiber can be SM or MM. But for ODN it is SM optical fiber. Used in patch panels.
A patch cord is a simplex optical cable with optical connectors at both ends. It consists of one optical fiber. It can be SM or MM, but for ODN, it is SM. The diameter of the patch cord is usually about 2 or 3 mm. Used in CO, headend, outdoor cabinets, etc. It can be of different lengths and has different optical connectors.
There are three basic structures of optical cables:
stranded loose tube optical cable,
slotted core optical cable, and
central tube optical cable.
In the next two tables, there are classifications of optical cables.
This is the end of this article. I will explain this topic in the next article >> ODN Engineering and Maintenance (5).
Thank you!
Reference:
HCIA-Access, ver. 2.5, Huawei Access Certification Training
