SUBSEA CABLE SPECIAL REPORT: East meets West at SubOptic 2016

The ninth SubOptic conference will be held in Dubai in April. Alice Shelton, programme chair for SubOptic 2016 as well as technical area manager for Alcatel-Lucent Submarine Networks, shares a preview of the key themes and issues that will be addressed throughout the event.


How does SubOptic support the subsea cable community?


The submarine cable industry is a small, close-knit community of enthusiasts, committed individuals and companies, all determined and devoted to providing connectivity and capacity to all corners of the globe, however remote, however politically challenged. Given the size of the industry, there is an expectation that if you don’t know somebody personally, then it’s sure you know somebody who knows him or her. 

The SubOptic organisation exists to promote the industry, foster debate, exchange ideas and act as an educational resource for the entire submarine cable telecommunications community. For each three year cycle culminating in the Conference, the participation on the organising committee may vary but it has always been steered and sponsored by leading members of the community, as a non-profit making, mutual, non-incorporated international organisation.


How has SubOptic evolved over the last 30 years?

SubOptic 2016 is the ninth conference to be organised under the SubOptic banner. The first event took place in Versailles in 1986, making the Dubai conference the 30th anniversary of the SubOptic conference. It is also the first time that a Suboptic conference has been held in the Middle East.

When the first SubOptic conference was in held in Versailles in 1986, optical submarine cables were in their infancy. The World Wide Web was perhaps somewhere on a drawing board and the driver for submarine systems was purely voice traffic. All systems were regenerator based with a single fibre pair having a capacity of 280Mbps.

We have since introduced optically amplified systems, originally based on a single wavelength per fibre pair, now deployed as dense Wavelength Division Multiplexed (DWDM) systems with in excess of 100 wavelengths per fibre, with individual channel bit rate capacities of 100Gbps and more, an increase in capacity of more than1,000 times each year.

In 1986, systems were procured and installed by a small group of companies, all based essentially around monopoly players, many of them government owned, from vendors who were considered the national champions in their country. It wasn’t until 1998 at our third event that the first private company initiatives were being discussed as deregulation allowed the introduction of systems based upon this approach. This led the industry into the dot.com mode with private companies building systems as if the fantasies of the internet based companies were actually real, or using the same traffic requirements to underpin the business case for parallel systems. Somehow we survived the burst of the dot.com bubble.

The nature of the traffic has also changed, with voice being a very small portion of the traffic today. Internet based traffic now predominates and this has led new players such as Google, Facebook and Microsoft to enter the market as cable owners to service their own needs. This change in traffic influences the way that traffic flows as it is no longer balanced and is mostly dependent upon where the majority of content is generated.

So over the past 30 years, the time that SubOptic has existed, the industry has seen many fundamental changes and SubOptic has been an observer and a recorder of these changes. We will be looking back over this time with a session dedicated to the 30th anniversary of SubOptic.


What will be some of the key themes addressed at the conference this year?

The theme for the conference is ‘Emerging subsea networks - the world's expanding treasure’. Traditional point-to-point systems are more or less a thing of the past as systems are extended to Points of Presence (PoPs) and expanded into much larger meshed networks. These networks can be integrated into terrestrial networks with the intelligence of a control plane and a central coordination. We expect to debate software-defined networking (SDN) and network functions virtualisation (NFV) for submarine systems; an emerging network of networks transformed by new virtualised and dynamic functions. This will be the subject of one of the masterclass tutorials.

As well as the usual conference sessions of keynote speakers, roundtable debates and paper and poster presentations, SubOptic has always had the objective of ensuring educational content as part of the conference programme. This has developed into a focused afternoon of masterclass tutorial sessions before the official opening of the conference. SubOptic 2016 is compiling a programme of masterclasses reflecting the latest new topics of interest to the conference attendees whether they be technical, commercial or regulatory.


What research will be showcased at the event?

We are pleased to have confirmed a masterclass tutorial session to be provided by Professor Pölina Bayvel and researchers from the Optical Networks Group at University College London (UCL), currently engaged in the large EPRSC funded UNLOC project.

UNLOC - UNLocking the capacity of Optical Communications - is a programme funded by the UK Engineering and Physical Sciences Research Council (EPSRC) to research the future of optical communication systems.

It is recognised that global communication systems are rapidly approaching the fundamental information capacity of current optical fibre transmission technologies. To date, growth has been supported by falling cost/bit but by 2020 we may be running out of capacity. Capacity will become a rare commodity.  This will have a devastating impact on the economy, causing bandwidth to be rationed or prices to increase: either would be devastating for economic growth.

The success of next-generation multi-terabit/s optical transmission networks hinges on the development of optical transceiver subsystems that provide a significantly lower cost-per-bit than the extremely successful 100G predecessors they will be replacing. In addition, this must be achieved within the unique power constraints inherent to submarine optical networks, while simultaneously maintaining or indeed increasing transmission reach. To achieve this objective, significant research focus has been placed on the generation and reception of higher order modulation formats, such as dual polarisation 16QAM and 64QAM, which have already been demonstrated in laboratory based trans-oceanic transmission systems up to 10,000km.

However, as the order of the modulation format increases, a corresponding increase in launch power is required to achieve an acceptable signal-to-noise ratio at the end of the transmission link. Higher powers inevitably result in significant signal distortion arising from fibre nonlinearity, which, if uncompensated, will limit the throughput of future optical transport systems. The masterclass tutorial will review different nonlinearity mitigation techniques that will enable the transmission of higher order modulation formats over submarine systems which can significantly increase reach, capacity and spectral efficiency.


Why is the issue of optical power budgets so important to the industry right now?

Another result of the close-knit submarine cable community and the fact that everybody has previously worked with everybody else, is the willingness of the industry to collaborate on specific topics of interest. The activities of the SubOptic Interim Working Groups are one example of this, but there are also cross-industry Working Groups set up to prepare SubOptic masterclass tutorials.

Back in April this year Tony Frisch from Xtera invited anybody interested to join a working group on optical power budgets.  Two months later the Working Group had 12 members, all people with a wealth of experience in the industry, representing turnkey and upgrade suppliers, system owners, traditional carriers and OTT players.  A demonstration of the willingness to work together on a sensitive topic, the Working Group has been running since June now and is ready to present their findings at SubOptic 2016.

Optical power budgets are key to the supply or upgrade of any submarine system, yet they sometimes appear – or are made to appear – complex and difficult to understand. In reality, the essential principles are not that difficult to understand, even if deriving some of the numbers requires sophisticated tools and experience. The objective of the tutorial is de-mystify the essential processes, explain what the numbers mean and to show when it is necessary to go beyond approximations that are often used.

The masterclass will explain as simply as possible the essentials of how a power budget works and will clarify the essential similarities and differences between the two ITU templates which are used to present them. After this, a number of important refinements which aim to improve the accuracy of the budget will be explained. Finally there will be some discussion of how to compare or check budgets including real measurable parameters and how one might create and validate a budget for an ‘open system’, where the line is supplied independently of terminal equipment.


How does SubOptic ensure it supports the industry during the three year period between each event?

In 2008, SubOptic launched the first interim activity working group, an activity ongoing between conferences, aiming to ensure that SubOptic serves the industry in an enduring and supportive manner while at the same time fostering debate in between the three year conference cycle.

The first interim activity was to develop a framework based on best practice for a model submarine cable construction contract and associated guidance. These documents were presented at SubOptic 2010 and are still used today.

For SubOptic 2013, a group of industry experts from various companies led by Elaine Stafford from DRG, developed ‘The Guide’, focussing on the basic fundamentals of planning, constructing, owning and operating an undersea communications network, to fill a void in educational basics for both those who are new to the industry and those niche industry experts who wish to learn more about broad aspects of undersea telecommunications.

The current interim activity is on extending the life of submarine cable systems, led by Keith Schofield from Pioneer Consulting. As the early optically amplified systems continue to be upgraded and progress towards their design life, owners, suppliers and customers are developing ways confidently to assess the risks, extend the economic life of systems already in the water, and even to recover, redeploy and re-use systems. In the last two years, this cross-sectoral SubOptic Working Group of industry insiders has grappled with the issues that anyone thinking of upgrading, owning or taking capacity on an extended-life system needs to consider.

At SubOptic 2016 the findings of the Working Group will be presented during a Special Workshop Session on Thursday 21 April. The session will cover both Technical and Commercial issues of lifetime extension and will be presented by experts from Apollo, Vodafone, Xtera, Tata, Pioneer Consulting and Orange.