YOU ARE AT:5GOptimizing open RAN: Nokia, AT&T trial cloud-native RIC

Optimizing open RAN: Nokia, AT&T trial cloud-native RIC

Nokia exec says open RAN marked by both merit and hype

Nokia and AT&T today announced a successful trial of a Radio Intelligent Controller (RIC) on the carrier’s millimeter wave 5G network in New York City. Nokia’s Sandro Tavares, global head of mobile networks marketing, told RCR Wireless News the trial met its goals of improving spectral efficiency and proving out functionality of this particular set of technologies derived from O-RAN Alliance technical work.

O-RAN Alliance’s Working Group 3 focuses on the RIC and describes its goal as defining a RIC architecture to enable “near-real-time control and optimization of RAN elements and resources via fine-grained data collection and actions over E2 interface.”

In this trial, the RIC was deployed as a software instance. Measurement and optimization applications were used to collect live network data. Nokia refers to these applications as xApps; in this case the partners used Measurement Campaign, Automated Neighbor Relation and Admission Control.

Describing the trial, Tavares said, “It was focused on one specific part of the city so not many sites. One thing that is important to learn from the architecture is that one RIC instance can support several base station sites. The way the architecture is evolving, and especially on 5G networks, you can have the RIC co-localized with the centralized until that basically handles that part of the baseband processing. Then, from that, you can actually manage up to hundreds of distributed units that are going to be deployed in a city.”

More on the xApp concept. The focus in this trial was on RAN optimization but Tavares said this premise could be extended and open up “new possibilities of third-party applications on top of the network. Basically any service that would benefit from having access to low latency could benefit from having a more direct connection to the RAN. For example, in just an anecdotal way, if you’re looking to a video streaming service or a video communication service, you can have an xApp that can optimize the delivery of the video to the terminals.” 

He said next steps are to develop more xApps “and start to show the value and show the applications working at scale, and then move to an implementation in the future.”

AT&T’s Mazin Gilbert, vice president of technology and innovation, said in a statement, “This successful trial is a testament to what we can achieve through openness and collaboration. Together with the O-RAN Alliance, AT&T and Nokia will continue to develop and contribute to the E2 interface and the RIC platform to help enable an intelligent and flexible 5G network.”

Open but integrated RAN

Open RAN is, well, it’s complicated. It’s complicated from a technology point of view and it’s becoming increasingly complicated from a political point of view as the U.S. gears up to drop some major coin on getting rid of domestically deployed Huawei equipment, pressure allies to do the same, and potentially invest in 5G-related R&D activities.

The thesis statement for open RAN is that it gives operators the ability to pick and choose equipment, which would break vendor lock-in, potentially create more favorable economics and drive scale, while also fostering competition and innovation. The counter is that disaggregating RAN hardware and software forces a trade-off in performance, especially as it relates to advanced RAN functionality like dynamic spectrum sharing, multi-channel carrier aggregation and massive MIMO for instance.

In a recent webinar, Nokia CTO and President of Nokia Bell Labs Marcus Weldon said, “Not all openness is good and not all closed-ness is good. And equally, not always is it necessary to be highly integrated and in many cases it’s good to be more loosely integrated and dynamically interworked. Maybe where we should be aiming…is somewhere in the middle.” As operators strategize in an effort “to find the bullseye in the middle” Weldon’s advice is to “integrate what you have to and open what you can.”

Tavares picked up on this thread in a Wednesday conversation. “It is actually the big point of discussion right now. Of course open RAN is a big topic and is there a lot of merit in it and there is a lot of discussion around it, but there is a lot of hype around it as well. We are looking at a more facts-based approach to open RAN. What are the areas where first of all we can achieve the best results in a shorter period of time and what are the areas that add a lot of complexity and need a bit more work before they become a reality?” 

He said it’s a pragmatic approach meant to “get the benefits of openness with more choices for our customers, the innovation that come with the functionality like RIC, but without losing too much on performance or without delaying the adoption of these advanced features that are actually being required by our customers right now.”

To the cost point, Tavares sketched out a scenario where an operator is using a multi-vendor open RAN approach. To provide a single point of contact in case an issue arises, similar to how operators segment networks by region and vendor, the operator could designate one of its multiple open RAN vendors to serve as the lead, for lack of a better term, or even bring in another third party to aggregate the disaggregation.

Editor’s note: I’m borrowing the phrase “aggregate the disaggregation” from Neeraj Patel, vice president of solutions and general manager of software and services at Radisys. Watch this video for more on open RAN from Patel

Talking through the cost/benefit of cheaper equipment versus more vendors and the attendant coordination requirements, Tavares said, “The costs can actually add up and then the whole economic point may not make sense. That’s why it’s important to reduce a little bit of the hype–focus on the facts and do the work.”

For more on open RAN and cloud-native design for 5G networks, listen to this episode of Will 5G Change the World? where Tavares expounds on these topics and others.

And for even more takes on open RAN, listen to even more episodes of Will 5G Change the World?:

 

ABOUT AUTHOR

Sean Kinney, Editor in Chief
Editor-in-Chief Sean focuses on multiple subject areas including 5G, Open RAN, hybrid cloud, edge computing, and Industry 4.0. He also hosts Arden Media's podcast Will 5G Change the World? Prior to his work at RCR, Sean studied journalism and literature at the University of Mississippi then spent six years based in Key West, Florida, working as a reporter for the Miami Herald Media Company. He currently lives in Fayetteville, Arkansas.

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