BARCELONA, Spain—Verizon announced this week that it is embarking on a move to “open RAN” (oRAN) technology. It’s another major new effort by the carrier to make its network cheaper to run and easier to upgrade. But what exactly does it mean?
Turns out that it means a lot. It’s a major new network strategy for Verizon, it’s a significant event for the operator’s suppliers, and it highlights a significant new trend in the design and construction of wireless networks both in the United States and globally.
But to understand Verizon’s new oRAN effort, we need to start at the beginning. The traditional design of a wireless network involves one antenna, one radio and one baseband unit, typically all supplied by one company like Ericsson or Nokia. Indeed, Verizon’s current wireless network is roughly split in half between those two suppliers.
According to Verizon’s Nicola Palmer, the operator’s chief network engineer and head of the carrier’s wireless networks, that standard design took a turn toward centralization a few years ago, when the operator embarked on a program to centralize its baseband units, in part to launch SON (self-optimizing network) technology that can adjust the power of individual cell sites depending on real-time demand. "The way the networks optimize is by having a baseband that can control more cells than just one. So, the basics of cRAN is taking the baseband unit, the brains of a cell site, and pulling it back to a central location as opposed to having the brains sit on the pole or the tower or at the base of the tower."
And Verizon made serious progress on its cRAN efforts.
"We have thousands of these cRAN hubs throughout the U.S. They've already been identified. They are built out and equipped. And we have been in the process of centralizing those baseband units,” Palmer said.
The result of this work, Palmer said, is that 15 to 50 centrally managed cells can work in concert by using LTE Advanced features like remote electrical tilt to point a nest of antennas toward high-traffic areas during the day and then moving them slightly up at night to provide better coverage.
"That's what's happening today in cities all across the U.S.,” Palmer said.
From vRAN to oRAN
Verizon’s move to cRAN technology also allowed it to begin to implement a virtualized RAN, or vRAN. This is the process in which the proprietary baseband unit hardware, which sits below the antenna and the radio, is replaced with a general-purpose computer. In network lingo, that means that dedicated baseband hardware built by a company like Ericsson to specifically run its antenna and radio is replaced with commercial off-the-shelf hardware running standard, inexpensive computing architectures like x86.
This process of virtualizing the baseband in the radio access network (RAN) is part of a broader trend in the wireless and wider telecom industry in which operators are increasingly looking to move away from expensive, dedicated hardware from traditional suppliers and toward general-purpose computing equipment running software. The result is cheaper equipment that can be changed or upgraded more quickly through software.
"Now you can do a lot more,” Palmer explained. “The cRAN hubs become vRAN hubs, and now you have flexibility because they can be more quickly deployed. They can be scaled up and down. They can now communicate across cRAN hubs. … You can scale horizontally instead of vertically."
“I would say we're … probably still in the early stages of vRAN,” Palmer added. “We're working on that aggressively with our suppliers. They're all at different places.”
And not surprisingly, Verizon’s move to vRAN will then allow the operator to eventually implement what it’s calling open RAN.
"Open RAN requires a virtual RAN for the most part. Having a virtual RAN allows us to have best of breed in every piece of the network,” Palmer said.
She pointed again to the standard design of a wireless network, one in which a supplier like Ericsson provides everything from the baseband to the antenna. "You basically have an Ericsson market,” Palmer said of that setup.
"Our view is that you need to have those pieces disaggregated,” she said. “By separating hardware and software, you can get best of breed on each one. And that allows us, for example, to take a Samsung radio with an Ericsson baseband. … And that allows us to play the suppliers against each other. And to their strengths, to be honest."
And that’s what’s really going on in Verizon’s announcements here at the Mobile World Congress trade show. The company announced with Nokia a “successful trial of Cloud RAN in Oklahoma City, featuring its Cloud BTS with Verizon's Virtual Cloud Platform for the operator's vRAN 1.0 architecture.” And separately Verizon announced that Samsung “will supply Verizon with equipment including Remote Radio Heads and Baseband Units. These key network elements will also support Verizon’s Open RAN initiative by allowing the ability to interwork with other ecosystem providers.”
Palmer explained that Verizon essentially announced that its existing supplier Nokia is participating in its vRAN efforts, and that Samsung will join Nokia and Ericsson as one of its 4G suppliers, in part through a move to oRAN architecture.
"Bringing in a Samsung radio, right now it needs to be connected to a Samsung baseband. But if we can decouple that, that's where we're headed,” she said. “So, we're in the middle of doing that. I think Samsung will be our first example, but the vision is to go much bigger, longer term."
To be clear, Verizon is moving along with the rest of the industry to 5G network technology, and its vRAN and oRAN efforts will play into that. Verizon hasn’t yet announced its 5G suppliers, but thanks to its increasingly open and virtualized RAN, Palmer said Verizon now has more options.
"In 5G, part of the promise is that you will see some new players in different parts of the network,” she said. “And frankly we're encouraging that. Our doors are open to have discussions with disruptors, discussions with innovative providers."
AT&T and the new ORAN Alliance
The important thing to note is that Verizon is certainly not alone in its move toward c, v and oRANs. Here at the MWC show, a wide range of vendors and other players announced various products, tests and actions along the RAN trend line. Perhaps most important was the launch of the new ORAN Alliance, which sports members including AT&T, China Mobile, Deutsche Telekom, Docomo and Orange. The new alliance will “combine and extend the efforts of the C-RAN Alliance and the xRAN Forum into a single operator led effort.”
"To take full advantage of the flexibility of 5G, we have to go beyond the new radios and change the overall architecture of the end-to-end system," said AT&T’s Andre Fuetsch in a release from the new alliance. "Open modularity, intelligent software-defined networks, and virtualization will be essential to deliver agile services to our customers. ORAN will accelerate industry progress in these areas."
Indeed, vRAN and oRAN in particular require interoperability among components from different suppliers, which the new alliance said it would address specifically by “driving standards to adopt them as appropriate, and exploring open source where appropriate.”
However, even in the push for oRAN interoperability, there is fragmentation. Vodafone’s Luke Ibbetson explained that the operator is not a part of the new ORAN Alliance because Vodafone is instead putting all of its energy behind the OpenRAN effort within the Telecom Infra Project. The stated goal of that program is “the development of fully programmable RAN solutions based on General Purpose Processing Platforms and disaggregated software so they can benefit from the flexibility and faster pace of innovation capable with software-driven development.”
But the c, v and oRAN noise stretched across virtually all of the MWC show:
- TIM and Ericsson said they have started to digitalize TIM's nationwide radio access network in Italy starting in the city of Turin.
- JMA Wireless announced its XRAN Adaptive Baseband platform that the company said is “100% software that is designed to scale to commercial networks on off-the-shelf server technology.”
- Cisco announced it will form “a multivendor ecosystem designed to address these issues and accelerate the viability and adoption of Open vRAN solutions,” and said vendors including Altiostar, Aricent, Intel, Mavenir, Phazr, Red Hat and Tech Mahindra have agreed to join it.
- Dali Wireless announced the launch of its second-generation Dali Matrix virtual Fronthaul Interface, which the company said is part of the oRAN effort.
- Radisys showed off its “Open Service Delivery Software Solutions & Services” that in part allow operators to run software-powered, virtualized equipment.
- And Telefónica said it tested Parallel Wireless’ “programmable and Open RAN” in Latin America.
The trend toward software and virtualization is clearly prevalent across the telecom industry and is now making its way into the heart of the wireless network, the RAN. This means that established providers like Ericsson and Nokia will now go head-to-head against smaller, software-based startups as wireless network operators look to plug in select components in specific locations within their antenna-radio-baseband network technology stack.
The result ought to be not only more complex networks powered by more vendors, but also networks that can be more quickly and easily changed and upgraded. Indeed, Palmer noted that Verizon’s move to v and oRAN will aid the carrier in its quest to cut $10 billion in costs by 2021. — Mike | @mikeddano
"Editor's Corners" are opinion columns written by a member of the Fierce editorial team. They are edited for balance and accuracy.