GPON (Gigabit Passive Optical Network) is the largest fiber access technology for delivering gigabit Internet to businesses and homes. It’s an all-fiber technology that can be used to build Fiber to the Premises (FTTP) networks that connect subscribers to local ISPs.

GPON is the most fiber-efficient option for FTTH networks, providing a cost-effective method to deliver streaming video content and online applications with seemingly limitless bandwidth.

What are the benefits of GPON?

What is GPON and how does it work?

An Optical Line Terminal (OLT) can connect to many Optical Network Terminals (ONTs) or Optical Network Units (ONUs) via GPON (Gigabit Passive Optical Network). GPON networks use passive splitters between the ONT and ONT to split the wavelength so all ONTs on the fiber can see it. GPON standard says you can have up to 128 splits per GPON port, but traditional GPON deployments use 1:32 or 1:64 splits. GPON uses different wavelengths to transmit and receive traffic (1490nm downstream, 1310nm upstream). In the PON (passive optical network), the OLT broadcasts all traffic downstream to every ONT, and each ONT reads the traffic it’s supposed to read. ONTs use encryption so they can’t eavesdrop on traffic they aren’t supposed to see. Using time division multiplexing (TDM), the OLT coordinates transmission from ONTs so that they only transmit during their assigned timeslots on the PON.

Network with GPON

GPON’s remarkable flexibility makes it so popular. RFP video and IPTV, TDM voice and VoIP come with GPON. Also supports symmetric 10/100/1000 Ethernet and TDM or PWE3 (Pseudowire Emulation) based T1/E1.

GPON continues to be flexible in how the provider can lay out the network. For instance, the split ratio can be very low allowing for longer distances (up to 40km) and more bandwidth per subscriber or it could be up to 128 splits allowing for more subscribers over shorter distances. GPON includes DBA techniques so subscribers can get more bandwidth when they need it and free up unused bandwidth for others.

GPON at the premises

Subscribers install ONTs at their place of business. Residential ONTs have traditionally been installed on the outside of the home. In recent years, the trend has been to put them in the middle of the house. PON connects the ONT to the OLT, which is the point of demarcation for GPON services. The ONTs can include the home gateway/router, POT (Plain Old Telephone Service) or VoIP (Voice over IP) ports, as well as WiFi.

Costs reduced at OSP (outside plant)

Prior to PON, broadband was delivered over the same copper lines as POTs. Copper loops get more expensive to maintain as they age. Although fiber isn’t cheap to install, it has a longer lifespan than any services we can expect to use it for. Due to its longevity and the fact that PON networks are passive, OSP maintenance costs are usually just the cost of repairs when the fiber breaks or when a natural disaster happens. Besides, new boring technologies are being developed to make fiber installation cheaper, and by burying the fiber, maintenance and repair costs are further reduced.

If there is a fiber shortage in the OSP, the service provider can run a single fiber to a given location and split it closer to the subscribers. This reduces the need for long fiber runs. With a low split ratio on the PON, the distance between the OLT and ONT can be as high as 40km.

By combining the passive network, point-to-multipoint fiber saving technology, and extended reach, service providers can save thousands on outside plant cabinet and powering costs.

GPON standards

GPON conforms to the ITU G.984 standard, which includes amendments for Extended Reach GPON. G.984 was developed so that it could support higher data rates than earlier PON technologies like BPON and EPON. GPON offers better QoS and scalability than its predecessors. Because of features like DBA, GPON has become the solution of choice for Gigabit service providers. In the standard, GPON is defined to enable deployment of broadband services using TR-156 Using GPON Access in the Context of TR-101, making it fully compatible with existing access networks worldwide.

How long will GPON work for you?

Subscriber demand for bandwidth and high-quality experiences continues to grow. Fiber-optics are a technology that allows the speed of light in the OSP, so service providers can be future-proof. GPON has a long shelf life thanks to its excellent QoS and dynamic bandwidth allocation.

In addition, the ITU took meticulous care to ensure that next generation PON standards like XG-PON, XGS-PON, and NG-PON2 wouldn’t overlap with GPON or other capabilities like RF, so a new network could grow with service providers.