Basics to Understand GPON Technology

Basics to Understand GPON Technology

16 April, 2022

Basics to Understand GPON Technology

Gigabit Passive Optical Networks is a fiber optic technology (GPON Technology) that allows a higher speed of transmission and reception of data through a single fiber. With a point-to-multipoint architecture, it will enable optical fiber to the home, or a building. It allows access to Video, Voice, and Data and arose with the need to enhance copper networks. Now, copper and state-of-the-art fiber optic offer solutions adapted to each need.

Top Features & Architecture

A GPON network is capable of transmitting multiplexing divided by time (TDM), Ethernet, and ATP traffic. These type of networks consists of an OLT (Optical Line Terminals) unit, an ONU (Optical Network Unit) and a splitter (Splitter). The splitter will redirect the signal when necessary. The OLT unit takes all the optical signals in the form of light beams from the ONUs and converts them into electrical signals. OLTs typically support up to 72 ports. An ONU connects end users and forwards the signal back to the OLTs. A GPON Network supports a physical distance of up to 20 kilometers and can provide service to 64 end users. GPON uses upstream and downstream data using Optical Wavelength Division Multiplexing (WDM).

  • Protocol level security: Basic Encryption
  • Downstream speed: 2.4 Gbps
  • Upstream speed: 1.2 Gbps
  • Logic maximum distance: 60 km
  • Physical Maximum distance: 20 km

Top Features

  • Allows fiber connections up to 20 km between the OLT and the ONT. This is a great advantage because the old xDSL connections only reach a maximum of 5.5 km at a lower cone connection speed. This is the reason why users who live far from the switchboard used to suffer an interruption in connection with the speed contracted with their Internet provider.
  • It doesn’t need active intermediate equipment between the OLT and the ONT. It simplifies the deployment of fiber and allows much more straightforward and cheaper network typologies. Remember that splitters are passive elements.
  • Considerable reduction of costs for the operator because it allows sending many services at the same time though the same fiber connection. Thanks to the multiplexing we can simultaneously send:
  • Voice (VoIP phone)
  • Data (Internet)
  • TV and video (Multicast). We can send digital television in high definition (IPTV), video on demand (VOD), analog broadcast by RF.
  • The operation and maintenance for the operators are also simpler because GPON has remote management of the user’s equipment (ONT), download updates, operating parameters, and more.


  • Installers must be careful with mechanical joints to avoid losses and attenuations. They need specialized personnel and equipment to make fiber splices.
  • Identification and correction of the reflection are in the downstream channel (downstream from the OLT to the user’s ONT) and the ascending channel (upstream from the ONT to the switchboard with the OLT).

Installers can not place the hardware they want. With the xDSL lines, we could buy the neutral router that we wanted and put it. In fiber connections, the ONT must be registered in the OLT, and it is not worth any hardware. That is why it is necessary to obtain the configuration keys to be able to install the hardware that we want and follow the whole process and replaced the ONT and the integrated router of the operator on their own.