Let's learn more about the function of each component of GPON.

 The GPON standard is defined by the G.984 ITU-T recommendation for PON networks. It includes four main components:

 

Optical Line Terminal

The OLT can be considered the network manager of a gigabit passive optical network. Its role is to transmit and receive optical video, data and voice signals to and from the receiving ONT. The OLT transmits optical downstream signals at 1550 nm for video and 1490 nm for voice and data, and receives optical upstream signals at 1310 nm. This helps to avoid interruptions. GPON OLTs are installed at the service provider's location, usually a data center. Like the GPON ONT, the OLT converts the optical signals it receives into electrical signals. It is connected to an optical splitter via a backbone cable.

 

Fiber Optic Splitter

A fiber optic splitter is a passive component that splits a single fiber optic cable into multiple individual fiber optic strands that can be branched and connected to individual optical network terminals at end user locations. GPON splitters often have a specific split ratio, such as 1:64, 1:32, 1:16, 1:8, or 1:4, depending on the number of outputs required. Such splitters can be used for central splitting, splitting the signal among, say, 64 end users, or for cascaded splitting, where the splitter is connected to other splitters further down the line to create a more branched network.

 

Optical Network Terminal

The user endpoint in GPON is the ONT. h.Optical Network Terminal. This is a specialized modem that converts the optical signal to an electrical signal at the end user's premises. It enables broadband access on devices such as Wi-Fi, TV, and desktops. The ONT sends the aggregated and optimized data from end users back to the OLT.