Most 5G networks in operation today use a Non-Standalone (NSA) architecture, which links an LTE core to new radios supporting 5G frequency bands. The next step is to replace that evolved packet core with a new cloud-native 5G core. According to Jonathan Harvey, vice president of portfolio management for Nokia’s core networks, the 5G core must be able to support the low latency and high bandwidth that is expected from the latest generation of cellular technology.
Some of the high-level elements the 5G SA core can deliver, Harvey told RCR Wireless News, include network slicing and support for any access mechanism — mobile 5G, fixed access and so on. It also offers the ability to deploy the network on top of any cloud platform and to push the core out to the edge of the network.
“The other big one,” he continued, “is we’re moving to this service-based architecture, and that allows us to expose the network to the outside world, to third parties. It allows us to be more open, so we can plug and play far better, [and to] open up to more advanced use cases, which are coming in from outside the network itself.”
An evolution or a revolution?
For Harvey, the transition to a 5G Standalone (SA) core can be looked at from two different angles: The evolutionary approach and the revolutionary approach.
The evolutionary approach, he explained, involves simply evolving the network from what is in place today, while the revolutionary approach in more of a network overlay.
“On the evolutionary side […] it’s a software upgrade essentially to bring in the new elements,” he said, using Nokia’s functions like its subscriber data management platform as an example because it currently supports 3G and 4G, but with a software upgrade, will support 5G moving forward.
“The overlay-type model,” he continued, “is saying I have network in place [and] will bring in new network elements and overlay them over the top of my existing network.”
The approach an operator takes when transitioning to a 5G SA core — whether one of evolution or revolution — dictates where the operator should start the process within its network.
Harvey offered the example of having to cloudify the network versus bringing in an entirely new cloud-based 5G SA platform.
Public cloud or private cloud?
Harvey pressed the criticality of cloud in 5G more broadly, saying that the latest generation of cellular technology is “cloud focused.”
“You can’t really deploy 5G on physical network functions,” he added. “It needs to be cloud-based.”
However, Harvey revealed that he would not characterize the conversation as “private versus public,” as there are some “serious challenges with deploying a core network on top of public cloud,” mostly related to privacy and security issues that arise when user data is pushed out into the cloud.
Instead, the conversation is about the platform itself and the trend of public cloud providers moving to on-prem deployments. To support this claim, he cited Dish in the U.S. and Telenet in Belgium, both of which deployed a Nokia core, one on top of AWS and the other on top of Google Anthos, respectively.