It refers to the access mode of connecting communication terminals and homes by using optical fibers. In various types of broadband access, fiber-to-the-home is the development direction of wired broadband access.
Basically speaking, FTTH system include FTTH optical line termination (OLT), optical distribution network (ODN), and FTTH optical network termination (ONT).
OLT function: On one hand, the signals carrying various services are aggregated at the central office, sent to the access network according to a certain signal format for transmission to the end user. On the other hand, the signals from the end users are respectively sent to the netwok system according to the service type.
The ONT function: multiplexes and demultiplexes different services of the corresponding users, so that different service signals of different home terminals are multiplexed and transmitted in the same medium in the uplink direction.
In the downlind direction, different services are demultiplexed and sent to corresponding terminals (telephone, television, computer) through different interfaces.
ODN function: Connect the OLT and the ONT to provide a means of transmission between the OLT and the ONT.
ODN Network Constructure
The Centralized setting of Fiber Optical Splitter in Primary optical splitting.
When setting primary optical splitting scheme, the optical splitter is usually placed at the cable distribution point (at the fiber optical distribution frame). The Primary splitting scheme improves OLT utilization but increases the cost of using fiber optic cables.
The decentralized setting of Fiber Optical Splitter in Pmulti-level splitting.
When multi levels splitting scheme is adopted, an optical splitter can be placed at the OLT office (or cell room) and the user access point in addition to the optical cable distribution point.
The multi-level splitting scheme reduces the cost of the cable, but increases the line loss and the wiring management cost.
The terminal (or cell room) wiring equipment mainly refers to the fiber distribution frame. It is applied for the fixed protection of FTTH feeder cable, fiber distribution, combination, scheduling and so on. Moreover, the placement of the optical splitter should be considered, and the optical splitter should be connected in an active manner for line maintenance and line detection.
Cable distribution point wiring equipment mainly refers to optical distribution frame (indoor) and outdoor optical cabinet and optical cable joint closure. They are used to complete the fixing and transfer distribution of feeder cables and distribution cables.
|Fiber Optical Cabinet||Fiber Optical Joint Closure |
The user access point wiring devices mainly refers to the fiber optical patch panel, cable terminal box and so on. It is applied to further distribute the fiber in the distribution cable and enter a single user terminal in the form of a single cable.