Infinera leads 800g charge – but could 400g be the real beneficiary?

Long-distance and high-capacity optical transportation took another step forward earlier this year, with Infinera announcing a successful 800g transmission over 950km in a live trial, on a live network – a first for the industry. The trial, carried out on a third-party line with live multi-vendor traffic alongside it, could be a milestone for driving down traffic costs for operators – but could it also serve as the catalyst for improvements at 400g level?

Of course, the trial itself is primarily a breakthrough for traffic delivery at the long-haul level, and this was the initial reaction once Infinera broke the news. “The success of this trial proves our ability to transmit 800G high-baud-rate signals across significant distances, which will be instrumental in driving down network costs,” said Parthi Kandappan, Chief Technology Officer at Infinera – and with Ciena and Huawei also recently sending 800g traffic across multiple hundreds of kilometres, the race is on across the market to provide performance-optimised services for network operators to send across their backbones.

Looking at the Infinera trial in more detail, it represents a milestone in optical transmission. As one of the first use cases at a sufficient data rate to reach a large number of points within a specific provider’s network, the trial offers a combination of speed and distance that could enable carriers to make considerable cost savings on their operations. As SdxCentral reported in March, Infinera is trialling additional speed/distance combinations using the ICE6 transceivers – with internal trialling already having shown 600g transportation is possible over distances up to and exceeding 1,600km.

However, the race to 800g and similar capacity-focused transportation could also bring benefits for more footprint-optimised solutions, particularly the 400g services that provide the crucial and in-demand links between data centres, and which have formed the foundation of high-performance long-haul traffic to date. While 800g transport is a headline-grabber in its own right, a further benefit could come from what it enables - such as wider 400g transmission. The technology currently available on the 400g market is currently more focused on local and metro/regional rather than long haul, while improved 800g transportation over longer distances can connect data centres, move into access networks, and enable localised 5G transport.

Although the kind of capacity and packet size provided by 800g has been focused on the long-haul sphere, bringing more traffic over longer distances could be a catalyst for improved access for services of 400g and below, offering higher speeds, better data centre interconnectivity, and ultimately lower networking costs across the board.

One development that also plays into the recent 800g gains is 400ZR – an optical networking agreement in place to provide a footprint-optimised solution for high-capacity data transport over shorter distances, with connecting data centres one of the key applications. 400ZR aims to be pluggable, interoperable and eventually as disaggregated as possible, with the end goal to provide a similar level of vendor neutrality as some of the developments and initiatives seen on the software side of networking in recent times. This comes against the backdrop of a wide push towards open networking on the optical side, with the content provider-focused TIP project as well as AT&T-sponsored OpenROADM on the service provider side.

The general move towards open networking from the software side has made big strides in operating networks more efficiently. This will improve the underlying physical technology as well, which will need to happen at the local level if the full gains of 800g transportation are to be realised. However, while faster technology on shorter reaches is possible, it is likely to create bottlenecks, which will bring a cost management element into play if operators are required to add extra 100g links to compensate - hardware and software developments are needed in tandem.

That being said, a more reliable, quicker and higher-capacity long-haul link is one hardware advance that will help matters - as Kandappan rightly says, long-haul 800g is very likely to bring down network costs, optimise transportation and ultimately improve service delivery. But this won’t be limited to the long-haul – as 800g moves from trial to rollout, expect to see a knock-on effect in local and metro connection improvements as well.