Whilst high-bandwidth and low-latency applications such as video and Internet of Things put pressure on today's networks, they also have a role in driving innovation through demand. Earlier this year BT tested super channel and high-speed broadband optical transmission technologies, laying the foundation for a more robust standardization for optical networking.
Ahead of this year's NGON & DCI Europe which celebrates its 20th anniversary, Logan Armendone-Mowbray, editor with the NGON team at KNect365, spoke with Kevin Smith, Transmission Futures and Innovation at BT. Smith shares his views on the main challenges the industry faced, predictions for the next two to five years, the key technologies enabling scalable optical transmission and much more.
Read on for an edited version of the interview:
Broadband World News: Let's start by having a quick look at what has been happening in recent years. What have been the main challenges that the optical networking industry has faced?
Kevin Smith: Simply speaking, it has been, and continues to be, about bandwidth and cost and how we can deliver more for less. Widespread growth of Internet-based traffic, cloud services and TV-quality video streaming is driving around 50% growth every year in bandwidth, and with future 5G services on the horizon, even higher growth can be expected.
The most significant challenge over recent years has been how we can serve this demand but at a cost that allows us to deliver compelling and competitive products and services to our customers. This drives us to consider technology options that can deliver not only improved speed but also a fundamental shift in capacity efficiency of the underlying optical fiber transmission infrastructure. Right now, for example, 100Gbit/s per wavelength is our defacto standard for deployment at 50GHz frequency separation, but very actively, we are moving towards driving even higher optical transmission speeds together with increased optical efficiency and capacity per fiber.
BBWN: Looking forward, what's next for optical networking? Where do you see it in the next two to five years?
KS: We absolutely need to keep our focus on delivering increased optical fiber capacity in an extremely cost effective manner. As we talked about earlier, 100 Gbit/s per wavelength is now the defacto standard for our current core networks, but, of course, as an industry, we can't stop there and over the coming year, we will see wider deployment of 200G-based solutions, and possibly even 400G to further enhance the capacities of our optical fiber infrastructures. In addition, we are already seeing the increasing need for high-speed optical networks to support the delivery of very high precision time and phase information, especially with the advent of 5G services over this two- to five-year timescale.
Also, I would like to mention two words -- openness and programmability. These newer concepts are more generally associated with the higher layer networking protocols and web-scale data center environments, not so much with optical transmission networks, due largely to their more static fixed pipe tradition. Currently, we are looking to explore how some aspects of these concepts could be used to potentially benefit our optical transmission networks, such as additional operational efficiencies and flexibility, to allow us to deliver new services or feature sets more quickly and cost effectively.
BBWN: What are the key technologies enabling scalable optical transmission?
KS: There are a whole wealth of emerging optical-based transmission technologies that allow us to scale our transmission networks running over existing fiber infrastructures. Over recent years, we have seen huge strides in the optical physics side of things, including high-speed terminal devices moving from 10G to 40G to 100G and now to 200G and looking towards 400G and even higher. Key technology enablers for these terminal devices are the exploitation of advanced modulation techniques, with increased and flexible Baud-rates as well as multi-level, multi-dimensional modulation formats.
For the optical infrastructure, flexible-grid technology is key to enable flexibility, high speeds, and multi-terabit (superchannel) capacities. It is also worth highlighting the increased importance of the emergence of extended optical amplifier ranges beyond conventional C-band to, for example, L- and even S- band, to open up further optical spectrum, thereby allowing more wavelength channels and hence capacity over a single optical fiber. In the longer term, we already see a new breed of optical fibers that offer the potential for further optimized optical performance and capabilities.
To further simplify and scale optical networks cost effectively, we also need to look at how we manage and operate our networks, and the emerging opportunities afforded by technologies related to openness and programmability. By this I mean, for example, the potential of open line systems and a more realistic approach to disaggregated models that may allow for a more open, efficient and competitive way of building our future optical infrastructures. Emerging technology solutions for network telemetry could be a first compelling application of this new open world, whereby real-time network health and monitoring data can be used in a simple and scalable manner.
BBWN: How are BT trials and early deployments driving innovation?
KS: The experience we have gained by performing our industry leading technology trials and early deployments is invaluable to us and the wider industry. They give us a critical understanding of the maturity and real-world applicability of many advanced and leading-edge technologies. It means that we can work very closely, hand in glove, across our internal teams with our strategic suppliers, driving the innovative direction of the emerging technology, to ensure that it is fit for purpose, and meets the network requirements for future bandwidth growth. We like to refer to this as purposeful innovation. Very significantly, this means we have good confidence that the new and rapidly emerging technologies can help scale our networks gracefully and reliably to meet future bandwidth demands and are ready for the needs of our customers.
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— Logan Armendone-Mowbray, Editor, NGON team at KNect365.