Optical Networking, Redefined.
March 21, 2016

Standards For Next Generation 40 Gbps PON Approved By ITU-T

The ITU-T (International Telecommunication Union-Telecommunication Standardization Sector) has given first-stage approval to standards that will that will raise PON (Passive Optical Network) technology to new levels of throughput. The G-989 series of standards defines the characteristics of NG-PON2 (Next-Generation Passive Optical Network Stage 2) implementations that will allow “fiber-to-the-home” or ” fiber-to-the-premises” data rates to reach up to 40 Gbps. This is far beyond the capabilities of current PON technology. The ITU-T considers NG-PON2 to be the successor to GPON (Gigabyte-capable PON), which can reach rates of 2.488 Gbps downstream and 1.244 Gbps upstream, and 10G-PON (also called XG-PON1), which is capable of 10 Gbps downstream and 2.5 or 5 Gbps upstream. NG-PON2 is based on a multi-wavelength, point-to-multipoint architecture. It employs time and wavelength division multiplexing (TWDM) coupled with tunable optical transceivers to provide a maximum downstream access rate of 10 Gbps for each wavelength. Typically, four to eight wavelengths are employed in both directions. A single optical line terminal (OLT) at a provider’s central office, working through an optical splitter, can feed up to 256 optical network units (ONUs) at the customer premises. A great advantage of the new standard is that NG-PON2 can reuse existing optical distribution networks originally designed for GPON or XG-PON1. In addition, the NG-PON2 wavelength plan allows for coexistence with those earlier technologies on the same system. Major service providers, including Verizon, Energia, and Vodafone, have already conducted field trials of NG-PON2. The Verizon trial succeeded in delivering FiOS broadband to a customer’s home three miles away from the central office at speeds exceeding 10 Gbps. The ITU-T considers NG-PON2 to be “a major milestone in the field of access networking.” To learn more about advances in optical networking technology or to speak to a representative about our optical transceiver product offering, please contact us.