Low-Cost Tunable Optics Will Drive New Generation of Fiber Deployments

Note: This story was first published in The Online Reporter on August 19, 2015.

By Kendra R Chamberlain

Adtran’s proprietary approach to tunable optics will significantly bring down costs to deploy the technology and help drive and scale NG-PON2 deployments, the company claims. Adtran last week announced its first subscriber edge tunable (SET) optical transceivers that will enable broadband service providers to deliver 10 Gbps fiber to the home (FTTH) broadband services to residents and businesses.

The demand for broadband capacity and speeds is showing no signs of slowing, and Adtran believes FTTH is every broadband provider’s end game. Adtran CEO Tom Stanton said last week the company expects to see a 100-fold increase in broadband speeds, and 10- to 100-fold increase in broadband connections. Fiber optics is the only network technology that’ll be able to support these surges.

NG-PON2 solutions (that’s next-generation passive optical network 2), which support tunable optics, will enable broadband providers to future proof their existing fiber networks with a “no new wires” upgrade path and the ability to add capacity on the fly. The ITU’s specs for NG-PON2 support up to eight wavelengths of 10 Gbps symmetrical services over the same fiber network. Tunable optics enable broadband providers to deliver different services over different wavelengths on a single fiber cable, but the fixed-wavelength ONTs need to be swapped out for terminals that have tunable transceivers that are able to switch between wavelengths. “The way NG-PON2 works is you have a number of fixed wavelengths coming out from the OLT and on the ONT side, at the customer location, you have tunable optics that can tune into any one of those channels and speak a 10 Gig symmetric,” said Ryan McCowan, product manager at Adtran, during a press briefing last week.

But to date, the economics of tunable optics has remained an impediment to utilizing the technology. That’s where Adtran’s big breakthrough comes in. “Looking at the breakdown of the cost components of a PON system, as far as the electric and optics are concerned, it’s really dominated by the optical transceiver on the ONT side. There’s one of these for every customer, it tends to be more expensive than the electronics,” McCowan said. “We’ve developed the ability to design new optical transceivers here in-house, so instead of procuring that from the regular optical components supply chain, we’ve developed that competency to innovate and aggregate in a more deep-seeded way.”

NG-PON2’s multi-wavelength capabilities – with the help of Adtran’s SET optics – will enable network operators to pull more capacity out of existing fiber networks, the company said. Adtran claims its tunable transceivers offer a low-power, low-cost solution that can operate in a wide range of temperatures and doesn’t experience spectral drift. It’s able to tune between wavelengths “in the tens of milliseconds,” according to McCowan, but the company didn’t give much specifics beyond that. The solution will be available for trials in early 2017.

Verizon is the first broadband provider to announce intentions to upgrade its FiOS fiber network using NG-PON2. That’ll enable Verizon to deliver 10 Gbps symmetrical services over its fiber network. Verizon has tapped Adtran, Calix and Ericsson for its trial of NG-PON2 in parts of its footprint.

Feature image: Fiber Optic Globe (CC BY-SA 2.0) by JaredZammit