Türk Telekom and ZTE trial 50G PON

The firms announced that their trial delivered speeds in excess of 50 Gbps in the downstream over a single fibre, and did so in a way that was compatible with existing PON generations already deployed in Türk Telekom's network.

They are claiming a European first with the trial, specifically because of that compatibility. In the companies' own words, this was a three-in-one 50G PON Combo trial, which means that it used GPON and XGS-PON – the latter offering 10 Gbps symmetrical speeds – technologies alongside 50G PON.

In the trial, ZTE integrated its new three-in-one 50G PON Combo cards into Türk Telekom's existing OLT chassis, which proved that the operator's existing OLT is capable of evolving to 50G PON, when the time comes.

"This interoperability significantly expands the OLT's potential applications, paving the way for future services such as ultra-high bandwidth access, mobile xHaul, and deterministic campus networks in both home and enterprise environments," ZTE said.

Given that operators have already invested significant amounts in current GPON technologies, that compatibility will be crucial when we start to think about commercialisation of the technology. But despite the well-founded positivity in Türk Telekom and ZTE's announcement, it fails to acknowledge some of the hurdles still to be cleared before we get to commercial rollouts.

There are a number of technological barriers to 50G PON, one of which is alluded to in the ZTE announcement: while 50G PON can offer 50 Gbps-plus downstream speeds, it is not yet symmetrical, uplink speeds being half that or less.

Nonetheless, the trial is an important step in the ongoing development of 50G PON, even if future deployments are perhaps further away than the vendor community might like.

"In 2022, the 50G PON standard was finalized and received wide attention in the industry. It is expected that by 2025, the 50G PON industry chain will be ready for commercialization," said Yong Jie, CEO of ZTE Türkiye, in a statement.

Of course, the technology being ready for commercialisation is very different from operators pushing ahead with widespread commercial rollouts.

This time last year Dell'Oro Group predicted that total 50G PON equipment revenue will increase from less that US$3 million in 2023 to $1.5 billion in 2027. While that's a sizeable growth rate, 50G PON will still remain a moderate slice of the pie. However, the analyst firm noted that "much more significant growth is expected after 2027, as operators begin to evolve their 10Gbps PON networks to next-generation technologies."

Further, Dell'Oro pointed out that the coexistence of 50G PON with previous PON generations, and the implementation of combo PON, will be critical to the successful rollout of the technology, since operators have repeatedly indicated that they do not want to disrupt their optical distribution networks (ODNs) by moving to a new technology.

ZTE and Türk Telekom are clearly doing the right things when it comes to furthering the development of 50G PON. But real-world deployments of any real scale are unlikely until closer to the end of the decade.