By Dave Tanis, Senior Product Manager at AFL
The record for the fastest internet speed was broken for the second time in just over a year, with a staggering rate of 178 terabits per second. At this speed, the total global internet traffic could be carried on just four fibers. While this world record was achieved with lab equipment, even with today’s commercially available systems, a 48-fiber cable would be more than enough to accommodate all of today’s internet traffic.
So, why are cables being installed with higher and higher fiber counts given these tremendous advances in capacity per fiber? There are several reasons for this. First, higher speed systems running on a single fiber can be more expensive than multiple lower speed links running on multiple fibers – especially at short distances. Parallel optics applications, like 100G PSM4 which operates on eight fibers, are often more cost-effective than the equivalent serial fiber application. In these cases, using more fiber can save money.
Second, the security and ease of use provided by dedicated fibers has distinct advantages to sharing space on a fiber. While it makes economic sense to multiplex traffic onto long-haul terrestrial and subsea networks to save on transmission equipment costs, the same is not always the case for other networks. Dedicated fibers provide the flexibility and ease of re-configuration needed in metro, access, data centers and other shorter distance networks.
And finally, with the tremendous advances in optical fiber manufacturing, costs have come down significantly to the point where it just makes economic sense to include more fiber. Installation remains a significant expense, and the incremental cost of additional fiber can be small in comparison.
These factors have driven the desire for higher fiber count cables. The challenge comes in when these high fiber count cables have to fit into the existing ducts or overhead trays. Simply adding more layers of buffer tubes or another stack of ribbons is not an option given the increase in cable diameter.
To meet this challenge, a radically new approach to cable construction was required. AFL’s breakthrough technology, Wrapping Tube Cable (WTC) used with SpiderWeb Ribbon® (SWR®) makes substantially better use of the available space within a fiber cable structure, allowing for much higher fiber counts as well as significantly reduced diameter designs. For example, a 432-fiber Wrapping Tube Cable with SWR is actually smaller than a traditional 144-fiber cable with a loose tube structure.
Obviously, these new high-density cables require innovation in other areas to ensure a smooth transition as well as optimal performance. That will be covered in the next blog: Getting the Most out of a High-Fiber Diet Part 2 – Supporting Ecosystem.