The Importance of Testing and Training for Submarine Fiber Optic Networks

Posted by Kevin Miller on Fri, Oct 16, 2020 @ 15:10 PM

Undersea cabling has connected continents for more than 100 years.  With exponential growth in bandwidth demands, private companies have begun large investments in underwater fiber optic cable to serve their customers’ needs. Because of the unique deployment and additional risks associated with underwater cabling, training and testing with the help of M2 Optics is critical. 

The Underwater Network Dates to the 1800s

A CNN article discusses the history of underwater cabling, dating back to the age of the telegraph.  The first messages transmitted coming when, “the UK's Queen Victoria sent a congratulatory message to then US President James Buchanan, which was followed by a parade through the streets of New York, featuring a replica of a ship which helped lay the cable and fireworks over City Hall.”

Undersea cable has advanced dramatically since early Morse code, telegraph messages.  Where the first transmissions, according to the CNN article,  took “over 17 hours to deliver”, the Marea cable between Spain and the US is able to transmit at “speeds of up to 160 terabits per second”

According to an article in the Internet Health Report, “95 percent of the internet’s data and voice traffic travels between continents underwater.”  This makes the vast underwater network of cabling between continents critical to modern commerce, including the increasing use of the cloud and mobile internet.  

The Investment Dynamic has Changed

The exponential growth in bandwidth demand for streaming, cloud computing and other services requires high reliability and minimal latency.  While the initial cabling was laid by telecom companies who would create a consortium and then lease bandwidth capacity to businesses, as the demand and reliability requirements have grown, large internet companies such as Amazon, Facebook and Google have begun to fund their own cables to connect their global network of data centers in an effort to ensure a seamless and more secure customer experience for their users. 

A recent article by Viavi notes that there are “more than 380 active cables lying on the bottom of the ocean.”   The article goes on to note that “ demand for global bandwidth is growing at up to 40% each year with analysts predicting the installation of fiber optic cables to hit the 2 million kilometer range by 2020”

This increased demand comes with the goal and expectation of highly reliable, low latency submarine fiber optic cables.  Given that it costs hundreds of millions of dollars or more to complete these projects and they are not simple to maintain or change post-deployment, testing and training become critical to ensure these expectations can be met over the long term. 

Testing and Training are Critical 

Submarine fiber optic links present unique challenges for both the pre-deployment testing and post-deployment maintenance aspects, as well as training engineers to perform the related tasks, since accessing subsea cables is not a simple task.  With few exceptions, these lengths of fiber optic cable often span hundreds or thousands of kilometers, especially the transoceanic links between continents.

Additionally, special high-performance optical fibers have been developed and are utilized to reduce signal loss and provide the best transmission possible over these vast distances.  Two prominent submarine fibers in the market today are the Corning®️ VASCADE®️ series of fibers, as well as the OFS®️ TeraWave®️ Scuba.  Designed for the unforgiving environment below the sea, these submarine optical fibers offer significantly lower signal loss/attenuation vs standard communication fibers (max 0.15db/km loss vs 0.18db/km loss of standard fiber for example).  Additionally, as one might expect, these specialty fibers also carry a higher price tag than most standard communications fiber due the significant performance improvements they offer.

Whether they are a telecom, internet, or network device company, it is important that these players in submarine fiber technology have engineering teams that are first well-educated on these systems, and that the systems and devices they develop or select have been rigorously tested and certified before the actual deployment. 

Simulating a Submarine Fiber Network

Since engineers can’t easily access live submarine networks for training and testing purposes, having an ability to replicate the network in a lab setting is important.  One might initially think that this is not feasible given the extremely long distances of specialty fiber required to accurately simulate submarine fiber networks, but this is where M2 Optics can help.

Having designed ultra-efficient approaches for managing large quantities of fiber, Fiber Lab solutions make it possible to exactly simulate entire transoceanic links within a lab or training environment.  These rack-mount fiber solutions, which can include hundreds of kilometers in just a single unit, allow engineering teams to replicate the optical performance characteristics and latency for both known or proposed links that span thousands of kilometers.  Being able to condense fiber optic links that span portions of the globe into a single room results in an invaluable asset for testing and training applications.

Furthermore, every unit is fully-customized to the user’s specifications, supporting a virtually unlimited number of submarine fiber length configurations and increments, while allowing for related equipment like fiber amplifiers to be integrated at specific distance intervals as required.

With almost all of the internet traffic between continents traveling through submarine fiber, accurately simulating these networks is critical to ensure proper training of operators and testing of network devices connected to these cables in order to provide a reliable experience for ever-increasing internet traffic demands. 


1,320km in a single rack (Fiber Lab 3200R)

Learn more about M2 Optics Submarine Network and Latency Simulators




1 - Lin, Shirley (2020) The Future of Submarine Cabling, Viavi

2 - (2019) New Investors in Underwater Sea Cables, Internet Health Report 

3. Griffiths, James (2019) The global internet is powered by vast undersea cables. But they're vulnerable, CNN

Topics: fiber optic testing, submarine fiber cable