System Upgrades Edition
In This Issue:
All Optical Submarine Network Upgrades
Upgrading Cables Systems? More Possibilities That You Originally Think Of!
Reach, Reliability And Return On Investment: The 3R’s To Optimal Subsea Architecture
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Upgrading Cables Systems?
More Possibilities That You originally Think of!
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W
ith the predominance of subsea cable systems for international, long-distance connectivity and the CapEx constraints experienced in most parts of the world, upgrading existing submarine optical assets to maximize their capacity and extend their lifetime is of the utmost importance. Such upgrades allow system operators to efficiently address the skyrocketing need for bandwidth. Subsea cable system upgrades can have different flavors and can be applied to more or less complex systems. This article explores the different upgrade approaches that have been already applied in the field and can be considered in the future.Dry Upgrades
When only the dry plant is involved, the benefits of upgrading existing subsea cable infrastructures are now well known and accepted by the community. These benefits include a lower cost since no CapEx is required for laying new subsea cables, a shorter lead time that is mostly driven by the supply of the new Submarine Line Terminal Equipment (SLTE) to be connected to the cable, and no permitting issues making the availability date for the new capacity more predictable.
This has not been historically always the case. Initially, the original suppliers of the existing systems happily supported the notion that connecting an SLTE from another vendor would not work – or at least was not a good idea technically,
or could impact the system warranty, or could even cause some intellectual property issues to be dealt with by the cable operator. But by now the situation is quite different – with subsea cable system operators assessing upgrade possibilities not only before the end of the warranty period but sometimes even before the RFS date of the system! In fact it seems like the only reason why customers do not purchase the wet plant completely separate from the dry equipment is that they have not found a way (yet) for the wet plant supplier to guarantee performance and system capacity.
Xtera has been working on the upgrade of submarine cable systems since 2001 and carried out its first commercial upgrade project in Q1 2006. The major benefits from this relatively recently created upgrade market are more competition, more advanced technology at the terminal level and lower incremental price for new capacity. Upgrading SLTE in the cable landing stations typically requires a procurement and installation cycle of less than 8-months, compared with an average of 3 years for building a brand new long-haul cable system (depending on size). SLTE upgrade can be carried out on unrepeatered or repeatered cable systems with the main following two approaches:
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» Dark fiber upgrade: Lighting a dark fiber pair when one is available, or it is viable to migrate all traffic onto a lit fiber pair;
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» Overlay upgrade: Launching new optical wavelengths in addition to the ones from the existing SLTE equipment. This is generally carried out via an optical coupler to insert the new wavelengths into the line and a splitter at the receive end. For both upgrade options, there is the possibility to keep the original Line Monitoring Equipment (LME) or to switch to the LME equipment from the vendor supplying the new SLTE (provided of course that this vendor has the capabilities to monitor the submerged equipment). The new system design capacity is then governed by the characteristics of the line that largely consists of the optical fiber cable and repeaters. The key characteristics that may limit the maximal system capacity include optical attenuation (not only the original figure but also the increase due to multiple cable cuts/repairs if any) for unrepeatered systems, and the noise generated along the system as well as its chromatic dispersion map and reaction to increased optical powers in the fiber (nonlinear performance) for repeatered systems.
The market research firm Ovum publishes on a regular basis revenue figures for the supply of the SLTE and repeaters for subsea cable system (these revenue figures do not include subsea cable and marine operations). From Ovum data, the revenue figures for the dry upgrade market (i.e. supply of only SLTE for
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upgrading existing cable systems) can be estimated to represent about 50% of the total revenue figures for the supply of the SLTE and repeaters.
Wet Plant Reconfiguration
If upgrading the terminals is not, or no longer viable, the next obvious step in upgrading subsea cable systems for further improvement of their capacity can be to reconfigure the wet plant. This can be achieved in different ways, depending on the type and generation of cable system. Touching the wet plant, and not only the
equipment in the cable landing station, can have, however, very significant commercial and operational implications – making most people stay away and not even start thinking about it.
A new breath of life for unrepeatered systems
There are cases, however, where this can make a lot of sense, both technically and commercially. The simplest wet plant reconfiguration is the insertion of a Remote Optically Pumped Amplifier (ROPA) into an existing unrepeatered
cable system. Capacity wise adding a ROPA tremendously increases the system capacity: for a cable system designed for an end-of-life attenuation of about 65 dB and with a design capacity of 100 x 10G, the insertion of ROPA brings about 10 dB of extra gain in the cable and boosts the design capacity to 70 x 100G. The addition of a single component per direction, like a ROPA, brings a 6-Tb/s capacity increase per fiber pair in this example.
This upgrade is, however, not as simple as just plugging in a component into the optical path. Firstly, this is an out-of-service upgrade of the wet plant which cuts the line and requires traffic restoration. Secondly, in order to get full capacity benefit, it requires careful design with respect to ROPA design, location and characteristics that need to be optimized and adapted to the pre-existing wet plant. Thirdly, there are commercial and operational aspects that will be found for any type of upgrade where the wet plant is reconfigured. On the commercial side, the baseline cost of replacing/inserting a piece of wet plant is largely dependent on the water depth and burial requirements. Still using the example of an unrepeatered system, the cable is very often in shallow water and the ROPAs are generally 80 km away from the end points. Both facts require cable burial and consequently a non-negligible cost fort the ROPA insertion.
Another important factor is the cost of vessel mobilization. A way to minimize it
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is to check whether work can be performed as outside work of a maintenance ship (if it is, this work is usually interruptible). The type of vessel to be used also heavily impacts on the upgrade cost. In very shallow water, a mobile spread on an inshore vessel may be a better option than a cable repair ship. Still focusing on the example of an unrepeatered system where ROPAs are inserted, the marine work (single operation in shallow water, including burial) will take at least 6-10 days, at a cost of about $500k to $800k at today’s vessel costs (outside maintenance agreements). Of course this cost needs to be multiplied by the number of operations needed (e.g. 2 in the case of a single unrepeatered cable where a ROPA needs to be inserted at each end), and then compared to the financial benefit of the operation (e.g. return on invest by larger capacity to be sold). Using again the example of an unrepeatered cable system designed for an end-of-life attenuation of about 65 dB and with a design capacity of 100 x 10G, $1m to $1.6m are needed to insert two ROPAs; this cost offers a capacity increase of 6-Tb/s per fiber pair. In addition to the marine expenditure discussed above, there is also a cost to the operational impact: this is the cost of traffic restoration during the upgrade operation. This cost is heavily dependent on the “local” capacity market and capacity resources availability between the end points of the cable system to be upgraded.
Other Types of Wet Plant Reconfigurations
Assessing carefully the commercial and operational consequences, more complex wet plant reconfigurations beyond the insertion of ROPAs into a single unrepeatered cable system can be considered.
The first obvious type of wet plant reconfiguration is the replacement of faulty/ underspecified units. This corresponds for instance to the replacing of degraded wet plant components (e.g. repeaters).
Another type of wet plant reconfiguration can be the insertion of branching units in order to connect to new countries and address new markets along the main subsea trunk. The reconfiguration will be easier if short, un-powered spurs are to be added to an existing cable system. Insertion of branching units for adding long spurs with repeaters has been also carried out, but mostly with incumbent vendor so far. The main reason for the latter is that operators are concerned about the warranty for the wet plant (repeaters and cable) on the trunk route – which sounds familiar to the argument
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mentioned above when terminal upgrades were first introduced.
Redeployment of Decommissioned Cable Systems
Redeployment of cable systems is another type of wet plant reconfiguration which has been successfully implemented several times in the past three years. In addition to the usual motivations for upgrading a cable system, the main drivers to cable redeployment are the decommissioning of an old-generation cable and, sometimes, the legal obligation to recover the phased-out cable from the seabed in combination with need for capacity in another part of the world where thin pipes are sufficient and funding of a new cable would be difficult.
Palau National Communications shared their business case for cable relay at Submarine Networks World Singapore 2012 conference. For building new international optical connectivity, the new cable approach required $40 to 65M CapEx while the alternative cable relay option was estimated to about $30M. The cable relay approach will also speed up Palau National Communications project significantly, estimated to be in service within one year vs. three years for a brand new cable system.
In addition to simply redeploy the recovered cable as is, there are many variants to this relay approach. For instance, the original repeaters can be
removed and the fiber sections spliced to each other in order to build a new unrepeatered cable system. Another variant is to replace the original, old-generation repeaters by new-old-generation optical repeaters in order to increase the system capacity. Both operations can be carried out aboard the cable ship after the recovery of the cable and while sailing to the new location for redeployment.
Reconfiguration of Regenerated Cable Systems
A number of these systems are still in service or being retired, and still laid on the seafloor. They were originally deployed with optical-electrical-optical regenerators inserted in the cable every 50 to 80 km typically, with a bit rate of 280 or 565 Mb/s. Obviously the optical fibers were specified for single wavelength operation and may not be always suitable for WDM transmission.
From a capacity perspective, removing the PDH regenerators from a short cable system can lead to a significant capacity increase. Using the example of a 330-km, 565-Mb/s system, removing the regenerators and placing two ROPAs at the locations of two previous regenerators (in order to minimize the amount of marine operations) turns the regenerated system into an unrepeatered system with a design capacity exceeding 80 Gb/s assuming 10G waves. This represents a 150-fold increase in the cable system capacity by simply
removing the old PDH regenerators and inserting two ROPAs.
Longer regenerated cable systems can be considered for this type of reconfiguration with the replacement of the regenerators by optical repeaters. In this case, integration and test are highly critical in order to ensure proper mechanical, electrical and monitoring interworking between the original cable and the new optical repeaters, while maximizing the system capacity.
In conclusion, upgrading existing subsea cable systems can be achieved at different levels and applied to virtually all the cable types and generations. Challenging upgrades require, however, an in-depth expertise in order to fully assess and understand the fundamental limitations that govern the ultimate system capacity. Challenging upgrades require not only a strong experience in building and managing projects that can be more complex than the deployment of a new cable system, but also the capabilities of a full supplier for offering all the products and services that are necessary.
Note: Illustrations by courtesy of France Telecom Marine
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Bertrand Clesca is Head of Global Marketing for Xtera and is based in Paris, France. Bertrand has over twenty years’ experience in the optical telecommunications industry, having held a number of research, engineering, marketing and Sales positions in both small and large organizations. Bertrand joined Xtera in 2004 where his responsibilities included marketing, customer interactions, and business development for both submarine and terrestrial high-capacity networks in EMEA area before moving to his current Global Marketing position.
Bertrand Clesca holds an MSC in Physics and Optical Engineering from Ecole Superieure d’Optique, Orsay (France), an MSC in Telecommunications from Ecole Nationale Superieure des Telecommunications, Paris (France), and an MBA from Sciences Politiques, Paris (France).
Dr Herve Fevrier joined Xtera in 2000 and serves as the Executive Vice President and Chief Operating Officer. He provides both the strategic and tactical leadership that leads to the acquisition of new customers, development of new products, partnerships with vendors, and developers of complementary technologies.
Prior to Xtera, Dr Fevrier spent more than 17 years with Alcatel in a wide variety of responsibilities including Director of the Photonic Networks research unit, Sr Director for DWDM Product Development Worldwide, VP & GM Optical Networks Alcatel USA and VP Network and Product Strategy Alcatel Optics. Dr Fevrier received his doctoral degree in Physics from the University of Paris and he holds a Physics engineering degree from the Ecole Centrale de Paris.
Dr. Joerg Schwartz is responsible, as SVP, Submarine Turnkey Solutions, for Xtera’s Turnkey Solutions product offering, delivering end-to-end submarine solutions to network operators based on the company’s transmission, equipment, and project execution expertise. Prior to this, Joerg has directed the NXT system definition and developed Xtera’s systems engineering team, providing network solution design, field and lab trials, sales support, and systems research. Other previous experiences include engineering and operational management roles for Ericsson, submarine terminal development for Alcatel, and founding an optical components company.
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Maximizing Network Capacity, Reach & Value
Over land, under sea, worldwide
Global Supplier for Subsea Cable Systems
A pioneer in the upgrade of existing submarine cable systems, Xtera offers an extensive portfolio of solutions for submarine of repeatered or unrepeatered networks, starting from the supply of high-performance and reliable Submarine Line Terminal Equipment (SLTE) to the implementation of global systems.
With 100G already in commercial service on a repeatered cable system, Xtera can deploy new high-capacity cable systems or upgrading existing ones (by either replacing the existing SLTE or reconfiguring the wet plant). To discuss how our scalable solutions help our customers minimize cost and maximize revenue, for both new and existing cable infrastructures, contact Xtera by visiting www.xtera.com.
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notes on The Upgrade Market
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T
he ongoing march of technology has always been an important part of the submarine cable industry. When pertinent technology becomes available it redefines many different aspects of the industry. Possibly the most important of which has been the creation of optical cable which expectations of available capacity. One of the most recent technologies that have changed not only the equipment used but the way business is done has been capacity upgrades. For the first time systems can be improved either to meet their full design capacity or, in thecase with newer optical systems, beyond capacity. This is opposed to completely laying new cable with better technology to replace the old model.
The use of upgrades to improve a system has become growingly popular. This has given rise to a number of companies that either can or even specialize in providing upgrades. One such company is Alcatel-Lucent.
“We’ve sold upgrades since the optical era,” said Norma Spruce, ASN Marcom Director. She explained that since optical
became available roughly 20 years ago, they had dealt in a few forms of upgrades. It wasn’t until 2009, however, that the newest kind of upgrade became available, according to Olivier Courtois, Alcatel-Lucent system product line manager. This is thanks to developments in coherent detection, which has allowed possible upgrades to go up to or beyond 100 gigabits. It isn’t always easy though. “You can squeeze more out of a system design,” said Spruce. “But only if you know what you’re doing.” The process
As observed by a number of publications and Press Releases, the number of cable systems that are being upgraded is clearly on the rise. One of the major factors contributing to the new popularity of upgrading an older system is the low price point. Rather than go through the ordeal of implementing a new system, owners are choosing to get a few more years of life out of their already existing systems with an upgrade.
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of increasing capacity can change from system to system. The age, design, and a number of other factors dictate how much of an increase, how expensive it may be, or even if it can be done at all. Sometimes nothing can be done but increase to its ultimate capacity as dictated by the design. The effect of upgrades on the market is an even more far reaching issue. In the lasting economic difficulty of the last five years, a more cost effective option that completely replacing the cable of a city to increase capacity opens more than a few doors. It allows for a new, specialized
market. It creates competition among system suppliers with this new market for the repeat business with owners. It even creates possibilities for owners to request designs that plan future upgrades into them.
The new options and facets provided by this new market have become increasingly important. The submarine cable industry, like so many others, is highly dependent on growth. System suppliers in particular are threatened when there aren’t new systems being regularly created. The movement in the industry created by upgrades allows
for money to be made that otherwise wouldn’t be.
New technology can always have surprising effects and always build on each other. 20 years ago, companies began laying optic cable, creating new possibilities for capacity and changing the market in doing so. Now, the growth of the relatively new upgrade market has changed the game again, giving cost effective alternatives for owners. It can only be wondered what next big shift will be thanks to this one.
As the popularity of upgrading systems jumps and the demand for capacity increases, naturally the market will respond with improved and cheaper technology. In 2009, the upgrades seen were majorly 10G upgrades, whereas now in 2012, you will find that 100G is the new norm. As the upgrade market heats up, competition will drive cheaper and faster upgrade technology.
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Upgrades may utilize 10Gb/s, 40Gb/s or 100Gb/s transmission technology. 10Gb/s transponders may be used when low cost or rapid deployment is required; typically from 1 to 1 ½ times the original design capacity may be achieved; for example a system designed for 32 waves per fiber pair might be expanded to 40 or 48 waves. 40Gb/s upgrades have been offered for several years, but are rapidly being overtaken by 100Gb/s upgrades. 40Gb/s upgrades may deliver 2 to 2 ½ times the original design capacity; it is not usually possible to replace each 10Gb/s channel with a 40Gb/s channel, thus the improvement factor is less than 4. 100Gb/s upgrades have recently been announced, with the potential to achieve 4 times the original design capacity on some wet plant.
Owners may choose from these solutions to meet their specific needs: maximizing capacity, rapid deployment, lowest cost or some combination. The exact results depend on amplifier bandwidth, equalization, the chromatic dispersion map, and other factors. A typical upgrade will involve tests to characterize a fiber pair followed by trials of the equipment before a supplier commitment is made. Many upgrade designs now permit new channels to be added alongside existing channels, avoiding the need to remove existing terminal equipment from service.
(Excerpts from Submarine Cable Industry Report, Issue 1, July 2012)
With new and better technology, competition will begin creeping in from unexpected places. Over the last few years, the upgrade market has almost wholly been dominated by Infinera and Xtera. Traditionally, this industry is dominated by installers, such as TE Subcom and Alcatel Lucent; however this new emerging market seems to be almost completely driven by faces relatively new to the submarine world.
Stephen Jarvis is a freelance writer in the Washington D.C. area. He has published articles and done editorial work with several publications including Submarine Telecoms Forum. Also, he has been a speaker for the Popular Culture Association / American Culture Association National Conference.
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Maximizing Network Capacity, Reach & Value
Over land, under sea, worldwide
Global Supplier for Subsea Cable Systems
A pioneer in the upgrade of existing submarine cable systems, Xtera offers an extensive portfolio of solutions for submarine of repeatered or unrepeatered networks, starting from the supply of high-performance and reliable Submarine Line Terminal Equipment (SLTE) to the implementation of global systems.
With 100G already in commercial service on a repeatered cable system, Xtera can deploy new high-capacity cable systems or upgrading existing ones (by either replacing the existing SLTE or reconfiguring the wet plant). To discuss how our scalable solutions help our customers minimize cost and maximize revenue, for both new and existing cable infrastructures, contact Xtera by visiting www.xtera.com.
