Fiber to the home (FTTH) is the delivery of a communications signal over optical fiber from the operator’s switching equipment all the way to a home or business, thereby replacing existing copper infrastructure such as telephone wires and coaxial cable. Fiber to the home is a relatively new and fast growing method of providing vastly higher bandwidth to consumers and businesses, and thereby enabling more robust video, internet and voice services
FTTH network having major three components are as OPTICAL LINE TERMINAL (OLT) , OPTICAL DIATRIBUTION NETWORK (ODN) and OPTICAL NETWORK TERMINAL/UNIT (ONT/ONU)
OLT (Optical line terminal)
OLT is terminal equipment connected to the fiber backbone. It sends Ethernet data to the ONU/ONT, initiates and controls the ranging process, and records the ranging information. OLT allocates bandwidth to the ONU/ONT and controls the starting time and the transmission window size of the ONU/ONT transmission data.
ODN (Optical Distribution Network)
ODN is a FTTH fiber optic cable network based on PON equipment. Its role is to provide optical transmission channel between the OLT and ONT/ONU. According the function, ODN from the central office to the client can be the combination of following components :
- Optical Splitter
- Fiber Optics Cables( feeder , Secondary ,home line cable )
- Fiber Termination Cabinet(FTC) or Fiber Distribution Hub(FDH)
- Fiber distribution Point(FDP)
- Rosette Box
- Demarcation Box
- Field Assembly Connector
- pigtails
- patch cord
- Adapters
Based on the Splitter levels and network requirement , some operators using the single splitting level and some operators using two splitting levels . splitting levels determine the network architecture and components of the network
ONU/ONT (Optical network unit/Optical network Terminal)
ONU is a generic term denoting a device that terminates any one of the endpoints of a fiber to the premises network, implements a passive optical network (PON) protocol, and adapts PON PDUs to subscriber service interfaces. In some contexts, ONU implies a multiple subscriber device. Optical Network Terminal (ONT) is a special case of ONU that serves a single subscriber.
