How fast can fibre-optic go?

Charting the acceleration of fibre optic over the years

Earlier this year, global telecoms company Alcatel-Lucent claims to have set a new fibre optic world record with an impressive 31 Tbit/s data transfer over a single fibre cable, overtaking the previous record of 26 Tbit/s set by The Karlsruhe Institute of Technology (KIT) in May 2011, by a team of German, UK and Swiss scientists.

Setting fibre optic speed records

Faster laboratory speeds have been reported, with the most recent in 2012 by NEC and Corning Incorporated of 1.05 Pbit/s using a 12 core fibre and multiple WDM channels. What is most important about Alcatel-Lucent’s claim is that the transfer took place on a single long-haul 7200km optical fibre cable, similar in distance to transoceanic cable distances, means that this is a “real-world” world record speed that could potentially be active under the Atlantic within months.

Today’s fibre optic networks are capable of operating at astounding speeds. However, to meet the ever growing demands of a business infrastructure increasingly reliant on cloud-based services and with more and more devices using the Internet, the reduction of fibre optic light loss is still a priority.

Speeds can be radically boosted in short distance applications, such as in data centers, where cables are generally shorter and intertwined, but research continues into extending this increase with minimal signal degradation over greater distances, when referring to the percentage of light lost per kilometre of fibre. This is why Alcatel-Lucent’s announcement was so important – previous high speeds have been set at distances in the range 50-240 km, hardly useful from transoceanic cables.

In this blog post, we're taking a look at just what caused the boom in fibre optic speeds and how fast can fibre go.

Fibre optics' origins

To really answer this question, we need to look at the beginnings of fibre optics, how it's progressed and exciting test bed of experimentation.

Advancements into the area of optics started as far back as the 18th/19th century; a commonly-known example is the patent for an optical telephone system called the “Photophone” by Alexander Graham Bell in 1880.

Although not strictly fibre optics, the invention could be seen as paving the way towards future developments. Finding a practical and viable use for optics, in particular ‘fibre’ optics, and further research to enhance the technology was required, and that's just what happened.

Serious research into fibre bundles began in the 1920s. Enter John Logie Baird (England) and Clarence W. Hansell (US), who patented the idea of using a series of transparent rods to transmit images for TV and fax machines. But it's actually Heinrich Lamm, a medical student based in Munich, who is widely thought of as actually demonstrating image transmission via optical fibre bundles, although he was unable to patent his idea due to the British patent already filed by Hansell.

In 1954, Abraham van Heel (The Technical University of Delft in Holland) and Harold. H. Hopkins/Narinder Kapany (Imperial College in London) announced imaging bundles in the highly-regarded British journal, Nature. Although the bundles were unable to carry light over huge distances – the experiments are seen as a major eureka moment in the evolution of fibre optics.

A team at Standard Telecommunications Laboratories continued the studies into fibre and in 1966. Their findings? A report in the April issue of Laser Focus that the experimental optical waveguide developed at the lab had the potential to carry 1GB of information (the equivalent of 200 TV channels or more than 200,000 telephone channels)!

Carrying lots of information too? Click here to find out how fast your broadband can go with our free speed test.

And the studies didn't stop there, with investigations into the problem of signal degradation though light loss taking place 4 years later.

In 1970, single-mode fibres with attenuation at the 633-nanometer helium-neon line below 20 dB/km were revealed – by reducing light loss to this level, major leaps forward were taken in the advancement of the technology.

To follow was an exhilarating new era in fibre optic communications.

By 1977, fibres of 850nms were tested – naturally, the larger a laser is, the less degradation of light can be expected, therefore allowing for a much quicker transfer.

Research and experiments continued throughout the 80s, 90s and 00s, with a significant breakthrough in data transmission speeds thanks to the standardisation and adoption of Wave Division Multiplexing with ITU standard G.694.2 published in 2002 and subsequently modified in 2003.

WDM and “dark fibre”

Wave Division Multiplexing (“WDM”) was a significant breakthrough in fibre optics as it allowed multiple data channels to be carried at the same time on a single piece of fibre optic cable.

Initial implementations of “CWDM” (Course WDM) allowed between 4 and 8 wavelengths (also known as “lambdas” or “colors”), such as the Ethernet LX-4 standard which allowed a cable to carry four 3.125 Gbit/s data channels, resulting in 10Gbit/s aggregate. Modern systems using “DWDM” (Dense WDM), although much more expensive, can handle up to 160 data channels (also known as “signals” in WDM parlance) expanding basic a 10 Gbit/s system over a single fibre pair to over 1.6 Tbit/s.

The advent of WDM in the mid-2000s significantly reduced the cost of fibre optic technology and therefore the cost of bandwidth to businesses, by allowing network providers to run multiple services across the same physical cable – a process known as “virtual dark fibre”.

The term “dark fibre” originally referred to unused (“un-lit”) cable laid in the ground as spare capacity, but has more recently come to mean the ownership of entire fibre channels by businesses or other organisations, such as educational institutions or government bodies.

Dark fibre became more available when there was enormous overcapacity after the boom years of the late 1990s through 2001.

In the US, a mile of dark fibre that in the past would have sold for $1,200, now sells for as little as $200.

According to Gerry Butters, the former head of Lucent's Optical Networking Group at Bell Labs, Moore's law holds true with fibre optics.

The amount of data coming out of an optical fibre is doubling every nine months. When you exclude the transmission equipment upgrades, the cost of transmitting a bit over an optical network decreases by 50% every nine months.

This reduction in cost of fibre technology makes it more cost effective for a large business or organisation to run their own fibre WAN between sites.

And when it comes to single site businesses, the reduction in fibre costs year on year makes it much cheaper to maintain a high-speed fibre connection either over a shared/managed virtual dark fibre channel, managed by an ISP or network provider, or on a dedicated fibre cable, giving multiple channels and substantially increased connectivity.

WarwickNet case study

WarwickNet have a pair of dark fibres between Telehouse East and Interxion (Brick Lane). Earlier this year we added two new CWDM wavelengths of 10Gbit/s each alongside the existing 1Gbit/s services we had on these fibres, so we have a 10Gbit/s "ring" around our 3 London sites now. For the tech minded, we just lit 2 10Gbit/s waves at 1590nm and 1610nm.

Ready to liberate your business from poor speed? Take the first step by clicking here to complete our free coverage checker.


The next steps for fibre optics

Since 2009 we've seen a rapid acceleration in both data transmission rates and raw cable speeds.

Perhaps the biggest breakthroughs in fibre optics came in 2013, with not only Alcatel-Lucent’s announcement, but also advancements in the area of hollow-core fibre optics.

In March 2013, scientists working at the University of Southampton discovered a new way to push data using a special hollow fibre optic cable capable of transferring speeds of 73.7 Tbit/s on a single cable.

The elimination of glass as a barrier, in combination with improved hollow cables, has helped to nudge speeds up to very impressive levels; in this case, the data packets were being transferred at 99.7% of the speed of light, increasing the data throughput of the cable accordingly.

This amazing stat is rather less impressive than it sounds when applied to the real-world. Sadly, use of this new form of technology would require highly expensive re-laying of fibre optics cables, unlikely whilst there remains so much fibre already laid underground available for use.

The research efforts around increasing the raw data throughput of individual cables through the use of new hollow fibre technology whilst showing the way for the medium term are unlikely to have an significant impact in the short term. Right now, the infrastructure cost of laying new cables outweighs the benefits. 

Most real world activity in the short term will persist around increasing the speed across existing “solid” fibre optic cable, particularly at transoceanic lengths.

There will also be a continued push to make the faster speeds of fibre optic technology more easily applicable over the “last mile”, with “fibre into the business” providers such as WarwickNet continuing to grow significantly as businesses demand faster connectivity.

Additional improvements will occur in smaller distance/low bandwidth applications, such as within buildings and even in short box-to-box, backplane and chip-to-chip where optical use has been demonstrated in the laboratory.

For most businesses and organisations, the real benefit will be from the increasing cost-effectiveness of high-speed Internet connectivity over fibre optics.

Most taking advantage of ISPs such as WarwickNet who can aggregate multiple customers over the same fibre optics cables are doing so to great effect, but there's also an increasing number turning to taking on-board dedicated cables of their own; provided and managed by the same ISP, with substantially increased data connectivity speeds.

Need super speeds & reliability?

If you're looking for a leased line from 10Mbit/s up to 10,000Mbit/s (10Gbit/s) – WarwickNet can help.

Providing dedicated, un-contended, low latency connections to the Internet (DIA) or to MPLS networks, our services are typically delivered via fibre optic (although in some cases it is possible to deliver via other methods like EFM, VDSL & Wireless). You can expect to get:

  • 1:1 contention
  • High performance, low latency, low jitter
  • Fully managed service
  • 24/7 monitoring
  • Client access to monitoring of usage and bandwidth
  • IPv4 and IPv6 addressing as standard

If you want to liberate your business from the lag of poor broadband, just get in touch by filling in our form or calling us on +44 (0)24 7699 7222 to speak to a member of our team.