In FTTH (Fiber-to-the-Home) network design, splitter plays a crucial role in passive optical networks (PONs), allowing multiple users to share a single PON interface. Each fiber network architecture requires splitter installation, which is located between the OLT (Optical Line Terminal) of the PON and the ONT (Optical Network Terminal) serviced by the OLT. To successfully design and deploy an FTTH network, splitter type and ratio must be considered and addressed.
PON (passive optical network) is a point-to-multipoint fiber network structure that is the main technology for implementing an FTTH network. This network architecture has no active components in the signal transmission link and uses shared fibers to connect the central office to the passive optical splitter, which can accommodate multiple optical links. PON network splitting can be achieved through a local aggregation point splitter structure (first level splitter) or through a distributed splitter structure (second level or higher).
The splitter structure usually uses a splitter located in an optical fiber distribution hub, with the splitter directly connected to the OLT (Optical Line Terminal) on the central office side. On the other side of the OLT, 32 optical fibers are routed to users' homes and connected to ONT (Optical Network Terminals).
The distributed splitter structure is a point-to-multipoint architecture that uses splitters for splitting at network access points and local aggregation points. Through OLT, each of the four optical fibers in the first-level splitter is routed to an access point equipped with a second-level splitter. In this case, a total of optical fibers are connected to homes. In the distributed splitter structure, there can be more than two splitters, which are also called multi-level splitting, and the overall splitting ratio may be different.
1:N (N=2~64) or 2:N (N=2~64) optical splitters are commonly used in PONs, where N is the number of output ports. The optical input power is evenly distributed on all output ports. Generally, splitters are deployed in a star-shaped network and in a ring network to provide physical network redundancy. Different splitters may have different performance in your network, which can affect the splitter ratio design in the FTTH network and other PON networks. For FTTH networks and other PON networks, a star-shaped configuration using splitter ratio architecture is the most common.
There are advantages and disadvantages to using a local aggregation point splitter structure and a distributed splitter structure in FTTH network design. To choose a specific layered design, we need to evaluate the pros and cons of different layered designs combined with our actual application requirements, and choose the appropriate level split for our network. When designing the splitter ratio, it is important to remember that the longer the transmission distance requires a more stable and reliable signal transmission, the lower the splitter ratio should be.