Our society’s hunger for the bandwidth only optical fiber can deliver isn’t slowing down. Let’s review one 5-year cycle of innovation between 2014 compared to 2019 to see where we’ve been and where we are going.
In 2014, 100 Gb/s technology was addressed by demonstrating new concepts for how to transmit more bandwidth while using less bits. This was a dynamic shift from basic on-off-keying (OOK) of the laser transmitter used in the past. It would require the development and integration and implementation of advanced modulation formats, forward error correction (FEC) and coherent detection technologies to address speeds of 100 Gb/s and higher. Using these technologies in 2019, we can expect field trials of 400 Gb/s and hero experiments of 600 Gb/s transmission systems.
Meanwhile for those installing new cables, fiber counts of up to 6,912 fibers are now available. The use of Dense Wavelength Division Multiplexing, (DWDM) technology with over 100 optical channels per fiber continues to grow. Next-generation WDM-PON (passive optical networks) uses optical multiplexing for speeds up to 40 Gb/s linking business and high-end customers.
Market research studies show the implementation of FTTx and 5G transmission using G.652D single-mode fibers continues to be the optimum method for providing bandwidth. Service providers already have placed billion-dollar contracts to assure product availability.
What does this mean for most service providers? Unless there is massive construction with new optical cables, we must utilize what is built. This means using time division multiplexing (TDM) for higher speeds up to 10 Gb/s, using dark fibers, and/or deploying either coarse wavelength division multiplexing (CWDM) or DWDM technologies, for increasing transmission capacity.
What to Expect in 2019
New 5G installations will increase while FTTx will migrate from legacy G-PON (ITU) and EPON (IEEE) systems to second generation 10 Gb/s systems using coexistence with existing optical fibers and systems.
Testing and maintenance disciplines will require greater focus for network reliability. While the OTDR has been around for decades, its full capabilities have still not been used.
Expect to see more implementation of optical network management systems (ONMS) which integrate the OTDR, optical switch technology and network management systems. These systems operate 24/7 and monitor either dark fibers or operate “out of band” at longer 1625 nm and 1650 nm as defined by the ITU’s L.41 fiber optic maintenance standard. These systems monitor network security, construction, provisioning, infrastructure, and maintenance. By incorporating ONMS systems into key hub locations this will reduce response times from hours to minutes.
While fiber installations will maintain their tremendous growth rate for FTTx and 5G, the need to maintain and characterize fiber for high-speed transmission will be the key to address current and future demands required to deliver the bandwidth requirements of our communications society. New network monitoring systems providing active monitoring of the fiber plant will become essential for maintaining signal quality and system reliability in 2019 and beyond.