Most of Verizon’s 5G RAN traffic is still on its 4G core

Verizon was an early leader in network virtualization when it created its Verizon Cloud Platform (VCP) several years ago. And more recently, Verizon has been virtualizing parts of its radio access network (RAN).

This week, Fierce caught up with Adam Koeppe, SVP for technology strategy, architecture and planning at Verizon, to talk about all its virtualization efforts.

Adam
Adam Koeppe (Adam)

Verizon did much of the heavy-lifting, itself, for its VCP. It was an early adopter of the disaggregation concept, separating hardware from software in its core network. It uses agnostic hardware from the likes of Dell and HPE. And the core infrastructure uses operating software from Red Hat – first using Red Hat’s OpenStack and later using Red Hat’s OpenShift container-based cloud software. On top of that infrastructure, Verizon uses software for telecom functions from familiar vendors such as Ericsson, Nokia, Samsung and Oracle.

Koeppe said that on top of that stack, Verizon does a lot of development on the systems and tools that help it manage its network more efficiently and create more automation.

Verizon’s VCP supports its 4G and 5G core networks.

In October 2022 the carrier announced that it had begun to move customer traffic from its non-standalone (NSA) 4G core onto its standalone (SA) 5G core. NSA means that Verizon uses 5G in its RAN, while still relying on 4G in its core. SA means that Verizon uses 5G technology in both the RAN and the core.

As an update this week, Koeppe said, “Today, most of our 5G RAN traffic is running on NSA mode, using 4G core functions paired with 5G RAN functions. We are in the process of testing SA capabilities and will soon be migrating devices later this year from NSA to SA. Those 5G core functions are all virtual.”

It’s been a multi-year endeavor, but Verizon has accomplished a transition from a core network that traditionally relied on proprietary gear with integrated hardware and software to a virtualized core network. It managed this Herculean task through a cap-and-grow model, which means that it started integrating disaggregated virtual components in its network on a gradual basis. And when proprietary gear reached its end-of-life, that gear was replaced with virtualized infrastructure. All this had to happen while the carrier continued to transport live traffic on its network.

Asked if VCP handles both Verizon’s wireless as well as wired network functions, Koeppe said, “The best way to think of it is VCP has any application for the network that makes sense to virtualize. There are certain functions on the network that don’t work well in a virtual environment. There will be a handful of things that will stay physical. Like a cell site router is a physical piece of equipment that doesn’t have a path to virtual in the near term for us. But across the Verizon network, network functions could be for wireless or wired.”

Verizon vRAN

Koeppe said, “We put a lot of effort in building automation and orchestration on top of the core network functions, and we carried that same concept forward on the far edge — the cell site network.”

He said that cell sites are simpler than the core, and the learnings from the core have been super helpful.

In September 2022 Verizon said it had deployed more than 8,000 vRAN cell sites with the goal of deploying over 20,000 by the end of 2025. And now, the company says it’s making steady progress, having deployed vRAN at 10,000 cell sites. The company doesn’t disclose its total number of cell sites.

Koeppe said that Verizon is in the process of deploying equipment for its C-band spectrum, which requires it to touch many cell sites. Since it’s already doing work at these cell sites, it’s getting extra bang-for-the-buck by deploying vRAN simultaneously.

He said the deployment of vRAN, “is actually very similar to work in the core network.” It deploys hardware-agnostic gear with Intel chipsets and an operating system on top. Then it uses Samsung RAN software to run on that hardware. “If I didn’t have a vRAN, I’d be buying physical cell site equipment from Samsung instead of just RAN software,” he said.

Verizon has been very public about its vRAN partnership with Samsung. But Koeppe said that Verizon is also doing some vRAN tests with Ericsson.