Most emerging communications providers have decided to deploy multigigabit, service-capable XGS-PON technology to light up their fiber optic distribution networks. However, many incumbent network operators leverage XGS-PON with a hybrid approach. This allows them to maximize their decade(s) old GPON networks and only migrate these networks to XGS-PON when necessary, whether due to network capacity or competitive concerns. Following XGS-PON comes 50G PON. While it provides another deployment option, when will we see these solutions become available?

The Metaverse and the fourth industrial revolution

50G PON services, once fully productized and commercialized, will be supported by a robust component and system supplier ecosystem. This will allow the optical networks being built out today to support the expansion of Nx 10Gbit/s and 25Gbit/s services. This will also accelerate the convergence of residential broadband and smart city applications with SLA-based enterprise and 5G mobile base station connectivity. This will also serve as the foundation for dozens of emerging applications and hundreds of augmented and extended reality and industry 4.0 use cases. Keep reading for a quick review of the recent quarterly meeting of the International Telecommunication Union (ITU) standardization sector.

Adtran ONUs easily meet the new tighter standard.

ITU-T PON standards update

Most of the world’s largest service providers and PON solution suppliers met in person in Geneva on September 23-29 as part of the ITU-T Study Group 15 Question 2 (PON). Here are some of the highlights from the meeting:

• Greater PON network flexibility and utility will be standard
  Triple coexistence details were agreed to, supporting all three ITU PON technologies simultaneously on a single ODN: 50G PON, XGS-PON, and GPON. A third upstream wavelength band (1284-1288nm) will now be part of the 50G PON standard. 50G PON dual coexistence or Combo PON implementations will also be supported: 50G+XGS-PON or 50G+GPON.
• Ensuring Combo PON service quality, reliability
  On the topic of Combo PON, during this same meeting, tighter standardization was defined to ensure greater Combo PON (aka multi-PON) service quality and reliability by further limiting out-of-band noise levels. We are happy to report that Adtran ONUs easily meet this tighter standard.
• Symmetric 50Gbit/s one step closer to standardization
  50G upstream is the last major specification piece remaining for 50G PON. We should expect its standards ratification by the new year. You may recall that the 50G PON standard was initially ratified in September 2021 for asymmetric operation: 50Gbit/s downstream with either 12.5Gbit/s or 25Gbit/s upstream.
• Future PON – beyond 50Gbit/s
  During this Geneva meeting, the group also agreed to start work on a supplement (study project) called G.suppl.VHSP for very high-speed PON to study technologies beyond 50Gbit/s per channel, including but not limited to PAM4 and coherent modulation. This is the same approach used to study rates beyond 10Gbit/s (ITU-T G.sup64, 2018) that eventually led to 50G PON.

1 Gig to multigig to 10, 20, 30, 40 …

As the world’s fiber-to-the-home network operators build out their networks with today’s mature point-to-multi-point fiber access technologies, the next fiber broadband technology nears final standards definition, enabling samples of key next-generation components to become available in late 2023. This timeline could then precipitate standard-based prototype 50G PON OLT and ONT availability in late 2024 or early 2025, with early live network trials following.