Sprint COO of Technology Günther Ottendorfer (center) shows off the company's latest 5G gear.

SAN FRANCISCO – Sprint highlighted recent field tests using updated network technology that along with its ongoing work with virtualization are laying the groundwork for 5G deployments.

The most recent tests included enhanced antenna, radio access network (RAN), and backhaul technologies that showed significant performance advantages on its LTE-based 4G network. Results showed network data speeds in excess of 1 Gb/s and the ability to provide high network speeds to a large number of users in one location.

The tests were conducted in Plano, Texas, and Seattle, and were with network vendor Ericsson.

The news followed on the heels of a blog post last week by Günther Ottendorfer, chief operating officer of technology at Sprint, that shed light on the carrier’s virtualization efforts.

Ottendorfer wrote that the carrier has spent the past couple of years deploying its OpenStack cloud-based network functions virtualization (NFV) platform. He explained the deployment has been “an essential building block” as the carrier builds toward its 5G network.

“For the last two years, we have been trying to educate the whole team on how important it is,” Ottendorfer said at this week’s Mobile World Congress Americas event, referring to its NFV work. “It’s not a question of whether we do it, but when we shift the platform, and that’s working itself out.”

As part of its NFV update, Ottendorfer said Sprint is bringing new vendors into its ecosystem. This includes Metaswitch and Mavenir to handle various control and management functions within the IP-based network deployment.

As part of his blog post, Ottendorfer explained Sprint has been building a virtual core to replace standalone, bare metal platforms with a single NFV infrastructure (NFVI). This virtual core houses the carrier’s virtualized evolved packet core (vEPC) and IP multimedia subsystem (IMS) as virtualized network functions (VNFs).

However, this week he noted the carrier expects to rely on a combination of established and new vendors to help with the virtualization of network assets moving forward.

“NFV is a paradigm change for us in terms of suppliers,” Ottendorfer explained. “I believe for us it will be a combination of established vendors and then to bring in some new blood. Bringing in some new blood into a large company is very hard, but this was my opportunity to do it, and I am super happy. It’s not about doing everything with the small guys, it’s about having them as a force of innovation.”

The financial impact of bringing on new vendors should hit the bottom line, though Ottendorfer said the carrier is not yet ready to discuss potential costs associated with its move toward virtualization.

Thomas Norén, vice president of Ericsson's network products business unit, in a separate conversation said the vendor sees carriers carving OpEx savings from network virtualization plans.

“With virtualization, automation, and SDN the key is really to reduce OpEx,” Norén said. “Carriers really need to look at removing OpEx items that don’t provide value…CapEx should be spent on things that generate benefits for the user.”

Those comments were echoed by fellow vendor Nokia, where North America CTO Mike Murphy said he did not think there will ever be a CapEx advantage in migrating network RAN assets to a virtualized environment. Cost advantages will instead come from OpEx.

“The whole picture is that in a larger scale and over a longer time period, it will be more cost effective to run a virtualized network,” Murphy said.