1×64 PLC splitter.
Splitting Ratios: 1×N VS. 2×N
There are a number of splitting ratios available for splitter deployment, but the most common splitter deployed in a PON system is a uniform power splitter with a 1×N or 2×N splitting ratio, where the letter “N” means the number of output ports. The 1×N splitter are usually deployed in networks with a star configuration, while 2×N splitter are more suitable in networks with a ring configuration as shown below to provide physical network redundancy. The PLCal input power is distributed uniformly across all output ports. Although non-uniform power distribution is also available for fiber PLC splitter, such splitter are usually custom-made and command a premium. Besides, based on different data transmission distances, there are also some suggestions for splitting ratios selection. If your distance between OLT (PLCal line terminal) and ONU (PLC network unit) is long, like 20 km, you can use splitting ratio 1:32 to receive qualified fiber PLC signals, and when the distance between OLT and ONU is short, like 5 km, you can consider about 1:64 splitting ratio.
star configuration vs. ring configuration
Splitting Levels: Cascaded Splitting VS. Centralized Splitting
Depending on the customer distribution, there are two common deployment strategies of Fiber PLC splitter—cascaded splitting and centralized splitting.
Cascaded Splitting: In most cases, a cascaded splitter approach as shown below has no splitter in the central office. The OLT port is connected/spliced directly to an outside plant fiber. A first level of splitting (1:4 or 1:8) is installed in a closure, not far from the central office. A second level of splitter (1:16 or 1:8) resides in terminal boxes, very close to the customer premises (each splitter covering 8 to 16 homes). The inputs of these splitter are the fibers coming from the outputs of the first level splitter described above.
Centralized Splitting: A centralized splitter approach generally uses a combined splitting ratio of 1:64 (with a 1:2 splitter in the central office, and a 1:32 in an outside plant enclosure such as cabinet). These single-stage splitter can be placed at several locations in the network or housed at a central location. The 1:64 splitter could even be placed within the central office to provide a point-to-multipoint (P2P) outside plant network that still shares bandwidth across multiple customers as shown below, for instance a group of subscribers a short distance from the central office. But most often, the splitter are placed in the outside plant to reduce the amount of overall fiber required.