What is Open RAN (O-RAN)?

Key Takeaways

• What Open RAN Is: Open RAN disaggregates the traditional Radio Access Network into standardised, interoperable components — Radio Unit (RU), Distributed Unit (DU), and Centralized Unit (CU) — allowing operators to mix hardware and software from different vendors rather than being locked into a single supplier.
• Why It Matters: Vendor lock-in has been one of the highest-cost and most flexible constraints in mobile network deployment. Open RAN breaks that dependency, giving operators more control over their network architecture, procurement, and innovation roadmap.
• The RIC Advantage: The RAN Intelligent Controller (RIC) is one of Open RAN’s most significant additions — an AI/ML-driven layer that enables real-time and near-real-time optimization of network resources, something traditional proprietary RAN systems cannot easily support.
• The Reality in 2026: Open RAN is growing — AT&T is on track to move 70% of its wireless traffic onto open-capable platforms by the end of 2026 — but performance gaps, integration complexity, and a maturing ecosystem mean it is not yet a direct replacement for traditional RAN in all scenarios.
• Where It Is Heading: AI-native network management, tighter integration with Non-Terrestrial Networks (NTN), and the transition toward 6G are all pushing Open RAN further into the mainstream — but the technology still has ground to cover before it fully delivers on its original promises.

For most of the mobile network’s history, building a Radio Access Network meant committing to a single vendor — one company supplying the radios, the baseband hardware, and the software stack, all tightly integrated and largely incompatible with anyone else’s equipment. It worked, but it was expensive, inflexible, and gave operators very little room to negotiate or innovate.

Open RAN changes that. By splitting the RAN into standardised, interoperable components with open interfaces, it allows operators to mix hardware and software from different vendors — choosing the best option for each layer rather than accepting whatever a single supplier decides to offer.

The idea sounds straightforward. The reality of deploying it at scale has proven considerably more complex — but the momentum is real.

What is a Traditional RAN and Why Does It Matter?

To understand Open RAN, it helps to understand what it is replacing.

In a traditional RAN, the base station is a single integrated unit — the Remote Radio Head (RRH), the baseband unit (BBU), and all associated software come from the same vendor. Ericsson, Nokia, Huawei, and Samsung have dominated this space for decades. If an operator chose Ericsson for a deployment, they were essentially committed to Ericsson for hardware upgrades, software updates, and future expansion — often for the lifetime of that network infrastructure.

This proprietary model made networks expensive to build and slow to evolve. Operators had little negotiating power, and adding new capabilities meant waiting for the primary vendor’s roadmap rather than plugging in a best-of-breed solution from a specialist provider.

Open RAN was designed specifically to break this cycle.

How Does Open RAN Work?

Open RAN disaggregates the traditional base station into three distinct functional units, connected through open, standardised interfaces:

Radio Unit (RU): Handles the radio frequency side — transmitting and receiving signals over the air. The RU sits at the antenna site and converts digital baseband signals into RF signals for transmission, and back again on the receive path.

Distributed Unit (DU): Manages the real-time processing functions close to the antenna — physical layer processing, scheduling, and resource management. The DU handles the time-sensitive operations that cannot tolerate significant latency.

Centralized Unit (CU): Handles the non-real-time upper layer functions — mobility management, security, and higher-layer protocol processing. The CU can be hosted further from the antenna site, including in a cloud environment.

These three units are connected through standardised interfaces defined by the O-RAN Alliance — the Open Fronthaul between RU and DU, and the F1 interface between DU and CU. Because these interfaces are open and published, an operator can source the RU from one vendor, the DU from another, and the CU from a third — something that was simply not possible in a traditional proprietary RAN.

The RAN Intelligent Controller (RIC)

One of the most significant additions in the O-RAN architecture is the RAN Intelligent Controller, or RIC. This is a software platform that sits above the RU/DU/CU stack and enables AI and machine learning algorithms to optimize the network in real time.

The Near-RT RIC operates on a timescale of 10 milliseconds to 1 second — handling dynamic resource allocation, interference management, and load balancing. The Non-RT RIC operates on a longer timescale and handles policy management and AI model training.

This intelligence layer is what makes Open RAN more than just a disaggregation exercise. Traditional RAN vendors do offer optimization features, but they are proprietary and closed. The RIC opens this layer to third-party application developers — called xApps and rApps — creating an ecosystem of specialized optimization tools that operators can deploy independently of their hardware vendors.

Read about Cloud Radio Access Network

Advantages of Open RAN

Diversity and Innovation of Vendors

This is the core proposition. Operators are no longer tied to a single vendor’s hardware and software roadmap. They can source the best RU from one company, the most efficient DU from another, and run software from a specialist provider – creating genuine competition at every layer of the stack.

Cost Efficiency

Open RAN runs on Commercial Off-The-Shelf (COTS) servers and hardware — the same general-purpose compute infrastructure used in data centres. This significantly reduces both CAPEX on equipment and OPEX on maintenance, compared to expensive purpose-built proprietary hardware. Dell’s PowerEdge XR8000 series, launched in 2025, demonstrated that open RAN workloads can now achieve performance parity with traditional systems on a single server – which changes the economics considerably.

Scalability & Flexibility

Because hardware and software are decoupled, operators can scale network capacity independently – adding compute resources without replacing radios, or upgrading software without a hardware refresh cycle. This is particularly valuable in private 5G deployments and rural rollouts where deployment cost and speed matter most.

Cloud & AI Integration

The RIC architecture enables a level of network intelligence that traditional closed systems struggle to match. Operators can deploy xApps to optimise handover decisions, manage interference dynamically, or predict and respond to traffic patterns in near-real time — capabilities that previously required expensive proprietary vendor features.

Faster Innovation Cycles

Software and hardware are no longer inseparable, so upgrades can be implemented much sooner without proprietary vendor roadmaps.

Limitations and Challenges

Open RAN comes with real trade-offs that operators and network planners need to account for.

Performance Concerns

Proprietary RAN systems have been optimised over decades. Open RAN solutions, while improving rapidly, still lag in energy efficiency, latency in dense urban deployments, and reliability under peak load. GSMA Intelligence reported in late 2025 that performance remains the primary factor holding back broader operator commitment.

Integration Complexity

Combining hardware and software from multiple vendors requires extensive testing, certification, and system integration work. Operators need strong internal engineering teams or specialist system integrators – a high hidden cost not always visible in the headline CAPEX figures.

Security Risks

More vendors and more open interfaces mean a larger attack surface. The O-RAN Alliance’s Working Group 11 is addressing this through Zero Trust Architecture frameworks, but security in multi-vendor environments remains more complex than in a tightly controlled proprietary system.

Ecosystem Maturity

The Open RAN supply chain is still developing. EchoStar – one of the most high-profile greenfield Open RAN deployments in the US – exited the business in 2025, highlighting the risks of betting entirely on an ecosystem that has not yet fully stabilised.

Where is Open RAN Deployed Today?

Open RAN is no longer just a pilot technology – it is being deployed at commercial scale, though the distribution is uneven.

United States: AT&T signed a five-year deal with Ericsson in December 2023 worth up to $14 billion – the largest Open RAN commitment in history. The target is to move 70% of all wireless network traffic onto open-capable platforms by the end of 2026, and as of early 2026, AT&T is on track.

Japan: Japan has been one of the most aggressive Open RAN markets globally. Rakuten Mobile built the world’s first fully virtualised, cloud-native Open RAN network from scratch. NTT DOCOMO has been collaborating with global vendors to accelerate O-RAN integration, and NEC rolled out next-generation O-RAN radio units in February 2026 optimised for high-capacity 5G and private network applications.

Europe: Vodafone, Deutsche Telekom, and Orange are among the operators running Open RAN trials and early deployments. The European Union has actively supported Open RAN adoption as part of its strategy to reduce dependence on Chinese network equipment vendors.

Private Networks: Open RAN is finding strong commercial traction in private 5G deployments, where the flexibility of multi-vendor architecture aligns well with the specific requirements of industrial and enterprise customers.

According to ABI Research, Open RAN installs are expected to reach 22.52 million by 2026, up from 1.37 million in 2021 – a significant growth trajectory, even if the technology still accounts for a relatively small share of total global RAN deployments.

The Future of Open RAN: Toward 5G Advanced and 6G

Open RAN is expected to make a significant contribution towards 5G Advanced and pave the way for 6G networks.

AI-native networks: The RIC architecture is laying the foundation for truly AI-native network management. As AI models become more capable and the xApp ecosystem matures, the gap between Open RAN intelligence and traditional RAN optimization should narrow — and potentially reverse in Open RAN’s favour.

Non-Terrestrial Network (NTN) integration: The O-RAN Alliance is actively working on extending Open RAN architecture to satellite and High-Altitude Platform System (HAPS) nodes. This would enable seamless integration between terrestrial 5G and space-based connectivity — a key requirement for global coverage in the 6G era.

6G foundation: The disaggregated, software-driven, AI-enabled architecture of Open RAN is closely aligned with the principles expected to underpin 6G network design. Technologies like Reconfigurable Intelligent Surfaces (RIS) and sub-THz communication, which are central to 6G research, will need the kind of flexible, open architecture that O-RAN is building toward.

Energy efficiency: One of the areas where traditional RAN currently outperforms Open RAN is power consumption. This is a focus area for the O-RAN Alliance and its vendor ecosystem — with cloud-native sleep modes, AI-driven power management, and optimised COTS hardware all being actively developed to close this gap.

Conclusion

Open RAN is not yet a complete replacement for traditional RAN in all scenarios. But the direction of travel is clear. The operators, vendors, and standards bodies investing in it are not doing so for short-term reasons – they are building toward a network architecture that is more flexible, more intelligent, and more open than what came before. Whether the ecosystem fully delivers on that promise remains to be seen, but the commercial commitments being made in 2026 suggest the industry has moved past the question of whether Open RAN will succeed to the question of how quickly.

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