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 GPON system the max of 1:128 a split ratio, but is typically 1:32 or 1:64. This is possible up to 20 km between OLTs and ONUs, even with the use of optical connectors. Telecommunication operators rarely work with 1:128. And at shorter distances and without the use of optical connectors.
The new generation XG(S)-PON enables 1:256, and in laboratory conditions, Huawei succeeded with 1:512.
The number of splitting levels may vary, but it is recommended that there be one or two splitting levels. In urban areas, one splitting level is often done. In suburban and rural areas, two splitting levels are usually used.
The simplest ODN
The simplest ODN is a connection between OLT and ONUs via a single optical splitter. The mini or small optical splitter is usually used.
The mini-campus ODN
In the solution, the mini-campus ODN, OLT, optical splitter and ODN are located within the same cabinet. Rack-mounted optical splitters are used here for optical splitters, as we can see in the following figure. Indoor optical cables for connecting ONUs start from this cabinet.
ODNs in small and medium-sized campus
In this solution, the number of ONU devices is limited. In the same cabinet is OLT and frame-shaped integrated slicing and termination ODF. On each floor, there is a FAT (Fiber Access Terminal) from where the ONUs is connected. Between the cabinets with OLT and FAT are indoor vertical optical cables. This solution, we can see in the next figure.
ODNs in large campuses and FTTH scenarios
There is many ONUs in this solution. in CO or headend, there is OLT and cabinet-type ODF share. Next to the optical distribution point is the feeder optical cable. Fiber optic cable with a large number of fibers. From the optical distribution point to the optical access point there is a distribution optical cable. Fiber optic cable with less fiber. And finally, there are drop optical cables. Different ways of realizing the network. such as burial, duct, and aerial. One or two splitting levels are used. The next figure shows this solution.
This is the end of this article. I will explain this topic in the next article >> ODN Engineering and Maintenance (4).
Thank you!
Reference:
HCIA-Access, ver. 2.5, Huawei Access Certification Training
