The fiber-to-the-home (FTTH, fiber to the home) access network based on passive optical network technology (PON, passive optical network) is a point-to-multipoint network structure. to multiple end users. Optical splitters have two different distribution modes in the FTTH network: centralized distribution and cascaded distribution, corresponding to two splitting modes of primary splitting and secondary splitting respectively. These two light-splitting methods have their own advantages and disadvantages, which will be described in detail in this tutorial.
About primary spectrophotometer
One-level optical splitting means that the optical splitter between the optical line terminal (OLT, optical line terminal) and the optical network unit (ONU, optical network unit) is parallel, and its basic form is "OLT→optical splitter→ONU ", the splitting ratio of the optical splitter used here is usually 1:64. In the first-level optical splitting application, the optical splitter can be installed centrally at the central office, but in order to save the cost of optical fibers, the optical splitter is usually installed between the OLT and the ONU in practical applications. The central office and the optical splitter are connected through the backbone optical cable (also called the feeder optical cable), and the user terminal and the optical splitter are connected through the distribution optical cable. Among them, the backbone optical cable generally uses a general-purpose outdoor optical cable, and the number of cores ranges from 12 to 144 cores; the distribution optical cable should be selected according to the specific application environment, and a general-purpose outdoor optical cable is generally used. For some occasions, it may be necessary to choose a flame-retardant optical cable. .