December 2, 2018

A closer look at commonly used PON technologies

There are two major standards groups for PON technology, they are the Institute of Electrical and Electronics Engineers (IEEE) and the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T). The following article is about the introduction of different PON technology.

GEPON (Gigabit Ethernet passive optical network)

  • 1G / 10G symmetrical
  • Update from Ethernet protocols and components, bringing economies of scale
  • Highly scalable and flexible, with a cost-effective single management system
  • Can realize very dense networks and serve thousands of subscribers
  • Integrated support for Triple Play (internet, television and telephone), QoS (quality of service), IPTV (internet protocol television) and VoIP (voice over IP)
  • Less costly than previous GPON equipment
  • 10G EPON symmetrical supports 10G downstream and upstream.
  • 10G EPON asymmetrical supports 10G downstream and 1G upstream.

GPON (Gigabit PON)

  • IP-based protocol, used in most deployments and accommodates today and tomorrow’s demanding applications globally
  • 2.488Gbps downstream and 1.244Gbps upstream
  • Mostly single fiber, although the standard is specified as both a single and multi-fiber system
  • 10G PON—also called XG- PON, and based on the ITU-T G.987 standard—is designed to coexist with GPON devices on the same network


  • 10 Gbps symmetrical—an improvement from previous generations of XG-PON that offered only 10 Gbps downstream
  • Symmetrical bandwidth is ideal for today’s business services and mobile backhaul
  • Delivers four times the upstream speed of current XG-PON1 technology
  • Relatively easy to scale up existing fiber networks in response to demand
  • Less costly symmetrical service compared to other PON upgrade paths
  • Can co-exist with current generation GPON technology

WDM PON (wavelength division multiplexed PON)

  • Nonstandard type of PON, developed by specific companies
  • 10 Gbps symmetrical
  • Each wavelength can run at a different speed and protocol so there is an easy pay-as-you- grow upgrade
  • Converges wireless and wired services for distribution
  • Reuse of existing FTTH infrastructure may be limitedTemperature control is a challenge because of how wavelengths tend to drift with environmental temperatures


  • 40 Gbps symmetrical—possibly 80 Gbps in future
  • Extremely high bandwidth, multiple wavelengths and software-defined networking allow NG-PON2 to use a single fiber for different purposes
  • Hybrid with time and wavelength division multiplexing approach
  • NG-PON2 and GPON can share the optical distribution network (ODN), benefiting operators who combine business and residential services
  • Optics that can dynamically tune to a provisioned wavelength (“channel bonding”) enable a wide range of business, consumer and wireless-wireline services at relatively low operating costs