The latest target for virtualization is the passive optical network (PON), and the Broadband Forum is leading the charge. At the request of Japanese service provider NTT, the Broadband Forum is exploring ways to use network functions virtualization (NFV) and software-defined networking (SDN) to disaggregate the PON functions and use open interfaces.
The project, which has the catchy name of PON Abstraction Interface for TCAs, is two-fold, according to the Broadband Forum. The first phase will define the disaggregation policy and look at the interfaces required to disaggregate PON functions. The second phase will define the specifications for the application programming interfaces (APIs).
Currently, operators have to switch out PON equipment when a users’ usage changes or there’s an update to the network. But if the PON network can successfully be virtualized that would mean those types of changes could be handled via software, which significantly improves costs.
According to Robin Mersh, CEO of the Broadband Forum, this is an area all operators are considering. “I don’t think there is one operator that isn’t looking at how to virtualize certain elements of the PON network.”
Mersh notes that the virtualization of the PON would make 5G fronthaul and 5G backhaul much more cost effective.
But is there really a need for standards around the virtualization of PON? Mersh said yes, because while open source is fine for the “plumbing” of the network, standards are necessary for the management layers. “We recognize that there will be some interfaces that will be completely open. There will be frameworks that will be completely open. We want to bring these things together. It needs to be open but delivered in such a way that has the discipline of standards.”
What About 5G-PON?
But the Broadband Forum and NTT aren’t the only ones looking at virtualizing the PON. Last year South Korean operator SK Telecom said it was using what it called 5G-PON in about 10 percent of its network with plans to expand that to 30 percent this year.
The company described 5G-PON technology as using coarse wavelength duplex multiplexing (CWDM) subchannel technology to provide physical layer transport connections. It can adapt different types of transport signals and data rates using existing fiber. At the time, SK Telecom said it was hopeful that the 3GPP and ETSI might incorporate the company’s 5G-PON into the 5G standard.
Mersh said that SK Telecom is also a member of the Broadband Forum but wouldn’t say whether 5G-PON will be part of Broadband Forum’s PON Project.