How did the UK leap to the front of the pack with XGS-PON?

Did being slow off the mark create the ideal opportunity for the UK to lead the way with 10 Gigabit symmetrical PON? Let’s explore the country’s FTTH journey.
Ronan Kelly
Race horse

The UK was late to the full-fiber party. But when it did finally arrive it was able to do so while reaping the benefits of an emerging technology. In 2016, the ITU released a new fiber-to-the-home (FTTH) standard: 10 Gigabit symmetrical PON, more commonly known as XGS-PON. New entrant challenger operators saw an opportunity to capitalize on this new, higher-capacity solution as a means to differentiate their networks from other competitors. This occurred at a time when the evolving government policies and regulations coupled with declining returns from traditional safe haven investment vehicles presented investors with a chance to own part of an essential utility that would underpin connectivity for the coming century.

At this point in 2016, the 12-year-old Gigabit passive optical network (GPON) was considered the de facto standard amongst established fiber operators. Smaller new entrant operators in the UK, eager to differentiate themselves to both the target consumers and the investors who would fund their build, became early adopters of the newer XGS-PON technology, embracing the quadrupling of the downstream capacity XGS-PON brought versus that of GPON networks and its eightfold increase in upstream capacity. With XGS-PON, they could connect more customers using less equipment, making it a more cost-effective investment.

Many UK operators have also leveraged clever PON architectures to stretch XGS-PON’s capacity without compromising connection quality. For example, utilizing one-to-four splitters at central locations and at the network edge have a 1-to-32 splitter, this results in PON segments capable of servicing up to 128 customers per XGS-PON OLT port. Whenever networks look like they are becoming congested, they remove the first 1-4 split while maintaining a 1-32 split at the subscriber end, returning the network segment to an overall 1:32 split ratio. This minimizes upfront investment, reduces power consumption and it’s also a very efficient way to restore capacity as data demand grows. 

With XGS-PON, operators can connect more customers using less equipment, making it a more cost-effective investment.

Combo PON eases migration

You could now convincingly argue that the UK is one of the most advanced FTTH markets in Europe. The race is on, and now it’s up to markets like Portugal, Spain and Italy — countries that are actually much further along in their fiber buildouts — to accelerate their migration to XGS-PON and further supercharge connectivity for subscribers across the continent.

For larger UK operators, every pound saved on equipment connecting customers to their networks is vital. Companies such as Openreach have navigated the introduction of XGS-PON very well. Still leveraging GPON, effectively they are introducing a methodology known as Combo PON to ease the migration to higher-capacity services. This approach packs GPON and XGS-PON components into a single optical component, enabling operators to simultaneously deliver both GPON and XGS PON over the same fiber strand. Whenever the subscriber end is deemed to be a heavy user with multigigabit requirements, operators simply deploy an XGS-PON optical network terminal (ONT) in that customer's home, while continuing to deploy lower-cost GPON ONTs for more typical users.

The UK’s full-fiber future

The UK got lucky. It caught the XGS-PON wave at exactly the right time, and it’s been surfing atop it ever since. The technology is now found in fiber access networks all over Scotland, England, Northern Ireland and Wales, and this is great news for customers. With a longer shelf-life than legacy GPON, XGS-PON enables service providers to easily upgrade their networks as data demand rises, while the Combo PON approach shall further extend the life of the GPON assets through the migration of capacity-zapping users over to the higher-capacity XGS-PON.

Looking to the future, the potential of XGS-PON in the UK is immense. The groundwork laid by early adopters and the strategic integration by larger operators sets the stage for an expansive, robust digital infrastructure. This flexible, scalable and highly capable technology is not just about faster internet speeds, it’s a gateway to smarter cities and advanced IoT applications that boost economic growth and enhance and enrich our increasingly connected societies. 

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