Verizon continued the push to evolve its passive optical networking infrastructure using NG-PON2 technology, which the carrier plans to control using its software-defined networking (SDN) architecture.
The carrier said it recently proved interoperability of NG-PON2 using the OpenOMCI specification at its technology facility in Massachusetts. The spec defines the interface between the optical line terminal (OLT), which is typically located at the service provider’s central hub, and the optical networking terminal (ONT), which is near the end user.
The trial focused on ONT management and provisioning as well as transmission convergence layer features to support wireline and wireless transport services. Verizon noted these features were unique to the NG-PON2 technology compared with other PON systems.
Operators are increasing their use of software control over passive PON assets to boost the performance of deployed fiber. PON uses a point-to-multipoint architecture to enable a single optical fiber to serve multiple end-points.
In addition to potential cost savings tied to more efficient use of current assets, PON deployments can allow operators to reroute traffic over their fiber connections in case of an outage or service disruption.
Phased Software Approach
Denis Khotimsky, a member of Verizon’s technical staff and lead engineer on the trial, said the carrier is looking at “a phased approach for the evolution of NG-PON2 deployment toward [software-defined networking]- and [network functions virtualization]-based architecture using a common SDN and NFV infrastructure deployed in Verizon’s network.”
The migration is expected to initially include locating the network-side end-point of the ONT management and control channel at the OLT. This has been the practice used with current generation broadband PON and gigabit-PON systems.
Khotimsky said once the ONT management is virtualized, the network-side end-point of the ONT management and control channel may migrate to the cloud.
“The OpenOMCI specification, which essentially defines the management information base for the ONT, is expected to remain invariant to this change,” Khotimisky added.
Verizon earlier this year worked with Calix to demonstrate NG-PON2 channel bonding over fiber using its network operating system and software platform. Calix said it used its SDN platform to leverage channel bonding.
Verizon has been working on the NG-PON2 specification with Adtran, Broadcom, Cortina Access, Ericsson, Calix, and Intel. The work is designed to optimize the number of managed entities and methods that can be used to deploy a service function without the use of vendor-proprietary technology.
“The Verizon-led NG-PON2 interoperability effort is important, not only for Verizon but for NG-PON2 technology, and is based on lessons learned over the last 13 years of PON deployment and great partnerships,” said Vincent O’Byrne, director of technology at Verizon, in a statement. “We see this work as removing a major roadblock and helping accelerate NG-PON2 deployment.”
Deutsche Telekom, SK Telecom, and Vodafone participated in the latest trial as “virtual observers,” which included access to the specification, test plans, and results. Verizon has also shared the OpenOMCI specification with the industry for possible inclusion within the appropriate standards.
Verizon rival AT&T said it plans to conduct a 10-gigabit symmetric PON (XGS-PON) trial later this year as part of its plan to virtualize access functions within the last mile of its fiber network. Services to be supported include broadband and backhaul of wired and 5G wireless services.
NG-PON2 to Dominate 5G Backhaul
A Communications Industry Reseachers report predicts the optical networking industry will account for nearly 60 percent of the $2 billion spent on 5G backhaul by 2022. NG-PON2 is expected to dominate the segment, with more than $890 million spent on the technology.
“The long-term success of NG-PON technology in 5G backhaul will, however, depend on the expectations that the cost of this technology will plunge in the next few years as the result of less costly tunable components,” the report notes.
IHS Markit recently noted the optical networking market was seeing increased pressure to adopt open software solutions “to deliver more open and interoperable optical networks.”
The pressure has seen a number of initiatives launched toward that goal, including the Open ROADM MultiSource Agreement, the Telecom Infra Project’s Open Optical Packet Transport Group, the Open Networking Foundation (ONF), and Optical Interworking Forum (OIF).