USCellular targets ramp up of commercial C-RAN for 2024

NEW YORK CITY – UScellular is chasing a RAN disaggregation strategy.

The first step involves revamping the transport layer and implementing a centralized RAN strategy. Next, USCellular has its sights on launching vRAN and potentially open RAN as well, USCellular's Reggie Collette told Light Reading.*

The drivers behind USCellular's centralized RAN (C-RAN) strategy are improving RAN performance and lowering total cost of ownership (TCO). Collette added that another driving force is the opportunity to provide a foundation for future technological development in areas such as open RAN and vRAN (virtualized RAN).

But, moving from a distributed RAN to centralized RAN can be costly and time consuming if not executed with a thoughtful strategy, said Collette.

Figure 1: Reggie Collette, principal RAN engineer for USCellular, delivered a keynote on RAN disaggregation at Light Reading's 5G Transport event in New York this week.
(Image source: Kelsey Ziser, Light Reading)

USCellular recently launched a limited deployment of C-RAN technology with plans for commercial production in 2024.

"We've removed all the basebands from those macro sites, and we condensed them all into a macro hub. In this particular case, we've got three hubs in this cluster. But really, the only thing left out at macro sites anymore is just radio," said Collette during Light Reading's 5G Transport Event this week.

In this deployment, USCellular used a WDM active-active fronthaul solution, which Collette said supported a flexible architecture, reduced tower climbs and "gave us the greatest visibility to our fronthaul network."

Arriving at vRAN deployment doesn't mean the technology will be "plug and play," but by the time an organization is ready to deploy it, ideally the employees will be upskilled to the point where vRAN is more manageable, he said.

Within USCellular, RAN and transport teams have had to reach commonality and work together.

"You really need both teams, working together collaboratively up front very early in the process in order to be successful," said Collette.

Looking again at the potential benefits of moving to C-RAN, Collette noted that improved RAN performance will come from "reduced latencies between RAN compute hardware drives improvements in coordination and other eRAN features."

While there's an initial investment required to move toward disaggregation, the right approach will eventually deliver lower TCO, he explained. For example, switching from Ethernet to dark fiber delivers an immediate reduction in monthly recurring charge (MRC), he said.

Additional TCO benefits include "aggregation of traffic to a single Ethernet service at macro hub," and "more efficient port utilization of CU/DU hardware makes better use of future RAN compute resources," according to Collette.

Standalone 5G

USCellular also has big plans for launching standalone 5G in the near future.

The MNO has been working on standalone 5G for over a year with plans to launch in early 2023, said Collette. One of the biggest challenges his team has faced in prepping for SA is the sheer number of test cases required to validate the technology.

But the payoff will be worth it, said Collette, as USCellular plans to greatly expand its coverage area with standalone 5G.

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— Kelsey Kusterer Ziser, Senior Editor, Light Reading

(Editor's note: A previous version of this article stated that USCellular plans to launch commercial ORAN by 2025 or 2026. However, the service provider clarified that deploying open RAN is still under consideration and has not yet announced a commitment to launching open RAN. The headline has also been updated to reflect that change.)