Make no mistake, if you offer a 1 Gigabit-per-second symmetric broadband service you had better be able to deliver the goods. Even when you consider that the average peak time usage per broadband* user today is only around 2Mbps levels, that Gigabit Broadband ‘Killer app” still exists – the broadband speed test! – which needs to be supported. Most new Fiber-to-the-Home (FTTH) networks can handle this widely used application, having the available access capacity to both support the full Gigabit per second burst satisfying the network speed test while still supporting peak time applications.

Many industry analysts are surprised to hear that most Gigabit Broadband players are using the fiber sharing GPON technology, and not point to point (P2P) Ethernet, FTTH technology. The surprise is warranted as P2P, sometimes referred to as Active Ethernet, supports a dedicated fiber and full Gigabit of bandwidth to each user while GPON supports 2.5Gbps per ‘PON’ connection shared by 16 or 32 homes/businesses to download content (and a 1.25Gbps shared pipe for uploading content).

If broadband utilization growth continues at the yearly rate we have seen for the last 10 years (~40%) it will take 10 years until a 2.5Gbps GPON port can no longer support a Gigabit speed test (>47Mbps average user bandwidth at peak times). The FTTH network could tap out in less than 5 years if an older, less developed GPON FTTH service delivery platform/network was deployed OR more heavy users like business customer using 100+ Mbps were to be served.

This lack of FTTH platform development is akin to a highway having extra traffic lanes only part way between major interchanges. This accelerated network obsolescence results from the inability to funnel any more than half of the 2.5Gbps per PON traffic into the cloud. Many Gig service providers reduce the customer split from 32 to 16 to accommodate higher service rates, but that generally buys you only another couple of years at 40% growth rate before around 100Mbps per user ‘redlines’ the FTTH GPON platform. Next generation 10G PON technologies will be rolled out in the coming years that will extend the PON exhaustion date twice as far as today’s most robust GPON platforms. That is what 10G versus 2.5G per PON will get you – 1.5 to 2 times the life expectancy. 5 to 10 more years of growth–up until 500Mbps per user on average is consumed during peak times – before exhausting a NGPON2 10G PON interface. This would support the wide spread delivery Gigabit broadband services, and the current high growth rate out to somewhere near 2030. Indeed this continued growth likely won’t happen everywhere but is will happen in many places, especially where those heavy user enterprise customers begin subscribing to Gigabit Broadband.



Now please realize that we have only been discussing the FTTH service delivery platform sitting in the access or last mile network being impacted. A 1000 or more of these Gigabit services will be supported on a single Next Generation FTTH service delivery platform, pushing each platform to require high performance cloud-facing interfaces supporting near Terabit speeds (Tbps or 1 million Mbps) to effectively transport all the cloud-based applications from a 1000 aggregated Gigabit Broadband users. Just like the FTTH access network, the middle-mile or metro optical networks will need to be highly scalable to support this massive onramp of broadband traffic. Imagine if we only widened a city’s side streets, but never expanded highway interchanges, overpasses, turnpikes and lane count.

Today’s FTTH platforms generally have only a 10Gbps Ethernet connection between the access network and metro network connecting to the cloud. This is just 1% of the Tbps requirement modelled. Most of today’s second mile or metro networks are receiving a ‘packet optical’ upgrade as Gigabit Broadband continues to ramp. Packet Optical allows exponentially more traffic to be added onto a fiber link by using multiple wavelengths of light – as in dozens and dozens – as opposed to a single wavelength pair and blinks those lasers on and off at 10 or even a 100 times faster than access fiber – as in Fiber-to-the-Home – connected to a home or business.

*Note: I am calling a ‘broadband’ user someone with at least the average broadband speed in the U.S. which is about a 10Mbps connection. These people typically use more traffic during peak times than the average user with a smaller connection to the Internet. Broadband users use more bandwidth online gaming, watching YouTube, viewing shows on their Roku or Apple TV and (perhaps) even illegally streaming pay-per-view boxing .

Kurt Raaflaub leads ADTRAN’s strategic solutions marketing, and has more than 20 years’ experience in telecom. He has global solutions marketing responsibility for the areas of SDN/NFV, Gigabit Broadband, and Customer Connectivity directed at the residential, enterprise and backhaul markets. Prior to his current position, Raaflaub was responsible for directing ADTRAN’s Broadband, Carrier Ethernet and Packet Optical solutions marketing activities within ADTRAN’s Carrier Networks Division. In 2006, he joined ADTRAN from Nortel where for over a decade, he held various roles focused on marketing and managing new disruptive market opportunities. - See more at: