The emerging PON technologies accelerating worldwide gigabit deployment

The emerging PON technologies accelerating worldwide gigabit deployment

By Bernd Hesse, Chief Marketing Officer of the Board of Directors, Marketing and BASe Chair of Broadband Forum

Earlier this year, the Broadband Forum hosted its insightful ‘Future of PON technology update’ vBASe webinar, focusing on the emerging technologies set to revolutionize the Passive Optical Network (PON) market, as well as the evolution and changing trends ahead for the worldwide deployment of gigabit technology.

Featuring notable industry leaders and contributors from Calix, DZS, Nokia, FutureWei and PICadvanced, the informative webinar brought together key research findings, use cases and a preview of the emerging technologies shaping the industry for years to come. As ongoing demand for full fiber access and connectivity inside the home continues to heighten, a seamless customer experience becomes more critical than ever.

PON technology – a rapidly growing market

Since the insertion of PON into the telecom world in 1993, we have gone through many twists and turns to get where we are today.

The initial PON in 1993 provided a maximum shared bandwidth of 54 Mbps, which was sufficient at the time to support traditional Plain Old Telephone Service (POTS) services. Since then, the standard has been updated regularly to meet the ever-increasing demand for bandwidth. This has resulted in the industry introducing several generations of PON over the years, with today’s Time Division Multiplexed (TDM) PON standards providing shared capacity of 10 Gbps in both upstream and downstream directions. By using Wavelength Division Multiplexing (WDM), NG-PON2 can further increase capacity on the fiber by a factor of 4. Therefore, with multiple channels on a single fiber network, wavelength bonding can achieve a total shared capacity of 40G upstream and downstream. The key is to build the right infrastructure to support any speed.

The research presented in the webinar detailed a significant increase of rapidly growing PON deployments, most notably in the North American, EMEA and Asian markets, in addition to the already mature Chinese market. Numerous factors for this include the recent broadband plan introduced by the United States Government, 5G backhaul application requirements and cable technology rapidly driving fiber deployments. Of course, the Coronavirus pandemic has also driven people to work from home and spend more time using fixed broadband services, therefore increasing the overall demand for high-speed and cost-effective PON technology.

With this pent-up call for fiber technology only growing as time goes by, the industry may see a critical change in the overall usage of PON, in order to facilitate a new wave of innovative applications. According to Nokia’s Ronald Heron, Gigabit Passive Optical Network (GPON) is still leading the way for worldwide deployments, covering a 70% shipment share in the market. However, this is set to change rapidly, with 10 Gigabit Symmetrical PON (XGS-PON) projected to play an even greater role in the coming years as network capacity requirements continue to grow.

The rate of XGS-PON deployments is increasing rapidly, initially this was seen in new fiber rollouts where it only makes business sense to deploy PON technologies that will meet especially consumer broadband demands for the next 5 to 10 years. In addition, XGS-PON is increasingly also being deployed in existing ‘brownfield’ deployments to co-exist with any existing GPON services. This is especially true in high density urban areas as well as meeting the increasing demand for gigabit+ business services across the shared fiber infrastructure. Within the BASe series of PON webinars, service providers such as CityFIbre (UK), AT&T (USA) and Chorus (New Zealand) have exemplified the business and use case for their investments in XGS-PON

Moving forward, this high demand for both business and residential PON bandwidth will require deployments that exceed 10 Gbps going forward. In response, the ITU-T is developing 50G PON as the next higher rate in the G. series of standards after XGS-PON, intended to serve multiple use cases including 5G xHaul. In the shorter term, the 25GS-PON Multi-Source Agreement (MSA), which combines IEEE 25G Optics with the ITU XGS-PON layer, is expected to start shipments in 2022. Both the 25G and 50G technologies had their adherents in the webinar, with the imminent availability and compatibility of 25G noted versus the higher bandwidth and the standardization path taken by 50G.

The upcoming PON standards ready to deploy

The BASe webinar series has highlighted multiple specifications supported by the Broadband Forum that are set to facilitate the emerging applications in the future, as well as support the global shift from GPON to XGS-PON. A major upcoming standard for widespread vendor usage is the IEEE high speed PON – 802.3ca 25G/50G-EPON. The standard is fully completed and is able to co-exist with either Ethernet Passive Optical Network (EPON) or 10G-EPON, allowing for more accessibility and flexibility for operators. More details on functionality are expected for the specification at the end of this year.

Another significant standard set for release from the IEEE group is the Super-PON – 802.3cs. The Super-PON is a form of TWDM-PON, which means time and wavelength division multiplexing. One primary advantage of the full definition Super-PON is that fiber access will still be possible without the need for infrastructure and physical assets such as optical equipment, allowing for ease of deployment, reduced costs and a wide range of access for up to 50km with a 1:64 ratio split.

In the ITU, new higher-speed PON specifications such as the G9802.1, G9804.1 Amendment 1, G.804.2 and the 50-GPON G9804.3 have been accepted in 2021, following successful plenaries in Q2.

What do the latest trends project for next year and beyond?

The need for future specification co-existence is an emerging debate in the industry, and it is to become an important feature for the future evolution of PON technology, helping to facilitate the development of emerging industry standards. PON co-existence is seen as the most beneficial method for turning away from outdated technologies when they’re no longer viable solutions. An example of this would be the co-existence of the current XGS-PON and the upcoming 50G-PON. However, this is dependent on the operator’s use case, as the solution wouldn’t be applicable to residential and smaller capacity connectivity.

In the years ahead, there will be a predicted shift towards higher capacity PON technology, with 25G/50G EPON set to make its debut next year and the steady transition to XGS-PON. As it stands, 10G-PON will still be the standard for residential Fiber-To-The-Home connectivity for the next decade, with 25G or 50G PON becoming widely used for enterprises with higher bandwidth requirements. As the requirement for continuous fiber-based connectivity continues to grow, so too does the need for cost-effective and speed efficient PON technology.

What is most evident from the BASe Fiber Access State of Play series of webinars is that XGS-PON is quickly replacing GPON as the current technology of choice for Telco investment.

There are some clear options in a mid-term to longer term for coexisting 25gig and 50gig with GPON/XGS-PON. Essentially operators need to design the most expensive part of any fiber broadband service, the physical optical distribution network, to ensure a single fiber build whatever technologies you currently or future deploy.

Sign up for the ‘Fiber Access State of Play: Future of PON Technology Update’ Webinar full recording and slide deck here.

Sign up for Fiber Access State of Play: “PON Deployments Reality Check” Webinar full recording and slide deck here.

Sign up for the ‘FTTP Deployments: Operator Requirements & Key Discussion Points’ Webinar full recording and slide deck here.