What is RAN?
To understand the different types of RAN, we must first understand what RAN is and its place in the telecoms ecosystem.
The RAN is the part of a wireless telecommunications system that connects user devices, like phones and computers, to the core network, delivering cellular and internet connectivity.
A traditional RAN architecture is made up of base stations—also known as cell towers—that process and transmit signals between user devices and the core network. These base stations are comprised of antennas that broadcast and receive wireless signals, radios that turn digital information into wireless signals, and baseband units (BBUs) that perform signal processing functions through advanced software and complex coding.
What is vRAN?
So, while we might mostly think of hardware when we think about cell towers, there is also a significant software element to RAN. Traditional RAN sees these two elements heavily intertwined, with RAN hardware and software being sold as a single package.
In an effort to modernise RAN, we have started untangling the software from the hardware, resulting in a system where network functions can be controlled remotely via software platforms and networks can be built using commercial off-the-shelf (COTS) BBUs to run proprietary software.
This is what vRAN is—virtual RAN—a Radio Access Network with virtualised network functions, separate from the hardware it runs on.
What are the benefits of vRAN?
Deploying RAN software on COTS baseband hardware grants operators greater flexibility and scalability, which is why it is growing in popularity. While a 2023 report from Omdia put vRAN’s share of the total market for RAN baseband products at just 10%, that is forecasted to grow to 20% by 2028.
Separating the software from the hardware also means that upgrades can be made more easily—updating virtual functions in software is much less complex than doing so for functions embedded in proprietary systems. With traditional RAN, adding 5G to a cell site requires investment in new hardware and an engineer’s day spent replacing the equipment on-site, whereas the whole process can be done remotely for vRAN sites. This also benefits the end users, who see network improvements like 5G deployment much more quickly.
Aside from the business benefits for operators, vRAN architectures are far more suited to handling the complex and demanding requirements of 5G than traditional RAN, because of how they virtualise the signal processing functions that control and route traffic. Moving these functions to the cloud helps operators more effectively manage resource allocation and make real-time adjustments automatically.
What is Open RAN?
While vRAN cracks the door to vendor independence by disaggregating software from hardware, Open RAN aims to kick the door down.
Open RAN breaks the radio access network down into modular components, effectively ‘opening’ the RAN and delivering much higher levels of interoperability. In fact, O-RAN specifications, put in place by the O-RAN Alliance and adopted by ETSI, mean that operators building Open RAN infrastructure must conform to certain interoperability-enabling standards.
Distilling the RAN down to its core building blocks and dissecting it in this way allows operators to mix and match vendors, using COTS hardware and open software interfaces across their networks.
What are the benefits of Open RAN?
Open RAN does what it says on the tin—it offers an open approach to RAN, meaning that a lot of its benefits are centred around customisability and interoperability.
Open RAN architecture empowers operators to build best-in-show networks by mixing and matching hardware and software from different vendors. This also breeds innovation, as without the safety blanket of vendor lock-in, vendors are incentivised to make their offerings as attractive as possible.
Similarly to vRAN, Open RAN also grants operators greater flexibility and scalability. Networks built in line with O-RAN standards can optimise network performance in accordance with each operator’s specific requirements—an Open RAN network deployment is an agile one.
What’s the difference between vRAN and Open RAN?
vRAN is about decoupling the traditionally intertwined software and hardware elements of RAN, whereas Open RAN aims to deliver a plug-and-play style of RAN, fostering an open network ecosystem.
Crucially, though, it’s not one or the other. Many Open RAN architectures are built on the principles of vRAN—breaking the RAN down into its base components lends itself to the separation of hardware and software.
However, where vRAN’s use of COTS components is limited to the baseband hardware, Open RAN employs COTS radio hardware too, as well as open software interfaces.
Who’s talking about vRAN and Open RAN?
vRAN and Open RAN are more than just concepts. In fact, recently, Three completed the first UK Open RAN deployment in a dense urban environment, with the Glasgow trial doubling 4G and 5G throughput during peak times.
That said, vRAN and Open RAN have faced somewhat tumultuous years recently. There are several complex reasons for this, but some of the most frequently cited are slowing data traffic growth, the cost of replacing existing hardware, operator hesitation around multi-vendor RAN architectures, and chip supply shortages.
This has dampened some spirits regarding the technology’s potential. In fact, in an infamous LinkedIn post earlier this year, Dimitris Mavrakis, Senior Research Director at ABI Research, wrote, “Open RAN is dead…Safe to say that Open RAN will not meet its initial promise.”
Despite this, other analysts decree that vRAN and Open RAN aren’t going anywhere. For example, a recent Dell’Oro report showed that RAN’s long-term trajectory remains healthy. In fact, Stefan Pongratz, VP of RAN Market Research for the analyst firm, said, “ Even with ongoing challenges and delays, we still anticipate that most operators will gradually incorporate more openness, virtualisation, intelligence, and automation into their RAN roadmaps.”
One thing that everyone can agree on, though, is that vRAN and Open RAN will continue to be an important part of network architecture conversations. Whether growth starts to accelerate or deployments tail off, the adoption of these approaches to the RAN will have wider implications for the telecoms industry, so this space is one to watch.
