Telia Estonia, part of Nordic and Baltic operator Telia Company, is running a proof of concept (PoC) of Adtran’s 50G PON technology to test how the next generation of passive optical networking can run alongside the GPON and XGS-PON services already on its fiber network. The trial uses Adtran’s SDX 6400 Series 50G PON platform and builds on Telia Estonia’s existing deployment of Adtran’s fiber access platform, according to an announcement Adtran issued from Tallinn on November 10, 2026.

The PoC will assess the operational requirements for introducing 50G PON next to deployed services on a common network infrastructure. Adtran says the SDX 6400 Series is designed to let GPON, XGS-PON and 50G PON coexist, so that a service provider can add capacity while keeping its existing optical distribution networks and introduce the new technology at a pace that matches customer demand. According to Adtran, the project will give Telia Estonia practical insight into how future services can be delivered over a common access platform without disruptive network upgrades.

Telia Estonia describes the trial as preparation for future residential and business broadband services rather than a launch. Its CTO, Janno Kriiska, refers to a 50 Gbit/s test carried out with Adtran, calls it successful and says the technology could eventually bring home internet services at that level to the mass market. Neither company has published test results, and the announcement does not give the upstream rate, the customer premises equipment, split ratios or reach, the number of sites or users in the trial, or a timetable for commercial service.

“Today, we cannot yet accurately predict which services we’ll be using in ten or twenty years’ time. What we can already see, however, is that AI solutions, cloud services and ever-growing data volumes require a robust and future-ready network,” said Janno Kriiska, CTO of Telia Estonia. “The 50Gbit/s test conducted together with Adtran demonstrates the significant potential of modern technologies and fiber-optic networks, while helping us prepare for the rollout of the next generation of digital services. The successful test is also good news for consumers, as this technology could enable the future delivery of home internet services to the mass market.”

Analysis

The trial is about coexistence more than peak speed. The ITU-T G.9804 series gives 50G-PON its own wavelengths so that it can share a passive optical distribution network with earlier PON generations, and that is what lets an operator upgrade one customer at a time without new splitters or fiber, or disruption to subscribers who stay on GPON or XGS-PON. Telia Estonia’s PoC is aimed at the operational side of that model, including running three generations on one access platform. The announcement does not say how the coexistence is implemented on the SDX 6400, for example with multi-generation optics on a single port or a separate coexistence element, or which upstream option is being tested, so the line rate in the trial beyond the 50 Gbit/s Kriiska cites is unknown.

Adtran has used the SDX 6400 Series in several earlier 50G PON projects covered by Converge Digest, all of them further along than Telia Estonia’s. Netomnia announced UK 50G PON plans with Adtran in October 2024 and in May 2025 launched what it described as the UK’s first commercial 50G PON service on the SDX 6400, over existing fiber. IdeaTek said in December 2024 it would build a 50G PON network in Kansas on the SDX 6400, and Sonic chose Adtran in November 2024 for a 50G PON rollout in California alongside its GPON and XGS-PON networks. Telia Estonia is at the test stage and has not committed to deployment. Rival suppliers are pursuing the same migration path: in May 2025 Nokia introduced a coexistence element that runs 10G, 25G and 50G PON over the same fiber.

For now, XGS-PON is still the main driver of operator spending. In its July 2026 forecast, Dell’Oro Group projected PON equipment revenue to grow at a 1.6% compound annual rate through 2030, led by XGS-PON deployments. Adtran’s third-quarter 2026 results showed the same split: optical networking revenue grew 11% to $114.5 million and access and aggregation rose 5% to $78.5 million, while subscriber solutions fell 13% to $88.1 million. Trials such as Telia Estonia’s give Adtran a foothold at a Telia Company operator ahead of a 50G upgrade cycle, but Kriiska’s “ten or twenty years” framing points to long-term planning rather than a near-term rollout.

We’re tracking the move to 50G PON as operators layer it onto existing GPON and XGS-PON fiber networks. See Converge Digest 50G PON coverage.