LOS ANGELES—Verizon is keen on taking advantage of the next generation of PON technology for its fiber-to-the-premises (FTTP) roll outs, but the service provider would like a way to service both business and residential customers on common infrastructure.
Speaking to attendees during the Lessons Learned from Global PON Deployment panel during this week’s OFC show, Vincent O'Byrne, director of network planning for Verizon, said that when it began deploying GPON the idea was that a common network would help it reduce capital costs.
“As we started deploying GPON, we were looking for a cost effective method for business services so we used GPON for that,” O’Byrne said. “In order to reduce cost, we were looking to be able to offer business and residential services on a single fiber.”
Avoiding business, residential service interruptions
However, offering business and residential services over one PON infrastructure isn’t simple. O’Byrne said that placing business and residential services on the same PON comes with various operational and technical issues.
“There are various safe times between the business and residential technician groups,” O’Byrne said. “Also, what happens if you have to reset the PON wavelength for residential customers on the PON; will you put a business customer out of service?”
Verizon has had to support its business and residential customers on dedicated optical line terminals (OLTs) from their central office on GPON.
“The net result because of a lot of these concerns is that it drives you to maintain a lot of your business and residential customers on separate OLTs,” O’Byrne said. “This did not drive down the costs of offering those services as much as we would like.”
While GPON has been Verizon’s main platform to satisfy its business and residential FTTP needs, the service provider is now looking at the next step in its fiber broadband development.
Like its peers AT&T and CenturyLink, Verizon has been looking at the next-gen options for FTTP: XG-PON, XGS-PON and NG-PON2.
In January, Verizon completed its first interoperability trial of NG-PON2 technology at its Verizon Labs location in Waltham, Massachusetts.
As part of that trial, Verizon demonstrated that equipment from different vendors on each end of a single fiber—one on the service provider’s endpoint and one at the customer premises—can deliver service without any end-user impact.
O’Byrne said that NG-PON2 would give it a large amount of bandwidth it could use to future-proof its last-mile network for several years.
“In the case of NG-PON2, you can deploy it initially on a 10/10 Gbps and pay as you grow to get up to 40 or 80 symmetrical Gbps,” O’Byrne said.
Looking forward, standards efforts are emerging to enable service providers to double capacity similar to the method used to increase speeds on copper-based DSL.
“Over time there is a capability being worked on in the standards to bond gigabit wavelengths together so you can start going by each wavelength,” O’Byrne said. “In theory if everything worked out perfectly, you could have a 40 Gbps system and a 40 Gbps OLT as well.”
Besides offering higher speeds out of the box, NG-PON2 could also allow Verizon to separate out business and residential customers on the same network system by placing them on their own optical wavelengths.
“We saw that we could make use of the wavelength capabilities of NG-PON2 to put business customers on one wavelength so you have this added flexibility of moving customers onto different wavelengths,” O’Byrne said.
In order to get to the next stage of FTTP deployment, O’Byrne says the industry needs three things: more vendor options and standards guidance, and considering legacy deployments.
“The optics ecosystem still needs more options to drive lower costs and more vendors,” O’Byrne said. “One of the other lessons learned is that there are a lot of standards, but it would be great to be more cognizant of legacy deployments.”
O’Byrne added that “if you have too many standards being deployed it ends up bifurcating the market and causes slower adoption of standards.”
Help is on the way
The Broadband Forum is integrating the NG-PON2 Forum into its fold to create the new NG-PON2 Council, aiming to accelerate the development of the passive optical networking standard as it continues to gain momentum with traditional telcos and competitive providers.
Since the Broadband Forum has been working on NG-PON2 standardization efforts for over a year via the Fiber Access Networks Working Group, the new organization could give Verizon and other large service providers guidance as they migrate to the next stage of FTTP deployments.