In a word, WOW! For the third consecutive year, Verizon and NEC Corporation of America announced they set an industry record, this time by successfully sending the highest-capacity transmissions for regional and long-haul distances over field fiber. In fact, one of the reasons this is so important is that it was done in a trial over fiber already in the ground and not a test done under simulated conditions. In two words, read on!

What They Did

The results of the latest trial, performed in late 2012, were accepted and presented as a post-deadline paper at the recent OFC/NFOEC Conference and Expo last month in Anaheim, Calif. What the paper describes is that the record was achieved by tightly packing optical channels in two bands of the optical fiber spectrum. Previous field transmission trials used a single optical band. By expanding from one band to two bands -- the C-band and the L-band -- Verizon and NEC were able to:

Transmit 40.5 terabits per second (1 terabit equals 1,000 gigabits) for a long-haul distance of more than 1,800 kilometers (1,118 miles)

Transmit 54.2 Tb/s over a regional distance of more than 630 kilometers (391 miles), using Verizon’s fiber loop outside Dallas

Without going into too many details of the history of fiber development and deployment in the U.S., it is important to note that the first deployments were always for longer-haul situations which made sense because the capacity was needed for interoffice and interexchange aggregated traffic. In fact, the very first fiber system to provide regular telecom voice service was on April 25, 1977 between two GTE central offices in Long Beach and Artesia, California. It was a 6-mile link using 6-strand multimode fiber running at 6.3 Mbps. As the latest record by Verizon and NEC shows, we have come a long way and a long distance in what really is not that long a period of time, especially since 80 percent of all of the world’s long-distance communications is now carried on fiber. 

 “Successful scientific accomplishments such as this demonstrate that Verizon is taking major steps to advance the industry’s understanding of high-capacity optical technology,” said Ed Chan, vice president of network technology for Verizon. “Verizon continues to address the challenge of maximizing performance on our global network while providing lasting business value and best-in-class services for our customers.”

As increased capacity demands (aka “the data storm”) are driven by video services, wireless applications, real-time gaming, massive data storage and increased IP services, network providers need to find ways to satisfy exploding demand without performing large scale infrastructure upgrades. By packing optical channels together and varying different properties of the lightwaves for specific transmission conditions, these trials prove the feasibility and related efficiencies of deploying up to 40 Tb/s for long-haul distances and more than 50 Tb/s for regional distances. In short, no need for an expensive “dig we must” replacement upgrade.

“NEC has been relentless in accelerating research and deployment of advanced optical networking solutions to help global carriers to meet the growth in network traffic,” said Toshio Suzuki, general manager for the Converged Network Division of NEC Corporation, Tokyo. “This field trial with Verizon is an exciting achievement that confirms our technology leadership and demonstrates the feasibility of delivering unmatched capacity over existing network infrastructure by utilizing all available frequency spectrum in optical fibers in the most effective manner.”

As anyone who has ever seen how fiber is laid, whether it be for long haul purposes or just down your street, you know that while techniques have become very advanced for pulling fibers, even for rather long distances, the reality is that pulling them out is a chore, particularly when service disruption is not an option. In fact, it is one of the reasons room is typically left in the conduit for packing in more fiber. That makes what has been accomplished here so interesting. 

Rather than pack the conduit it is making packing the fiber channels to optimize their use and thereby prolonging the life of what is in the ground. Telecom companies are going to look at such advancements in the same way there are looking at VDSL2 Vectoring technology to enable them to deliver broadband services in the local loop without having customers wait for that last mile or feet of fiber to their homes.