Are enterprises ready for open RAN?

The increasing deployment of 5G has brought about a new industry initiative called "Open RAN" (O-RAN). O-RAN is a broad movement to virtualize radio access network (RAN) functions through standardized interfaces, with the goal of maximizing the use of common off-the-shelf hardware and allowing for vendor diversity.

This is good news for telecom companies building large-scale public cellular networks. However, the specific O-RAN architecture being promoted does not fit well with existing enterprise IT infrastructure.

Stepping back, 5G deployments are on the rise. 5G introduces a new radio technology (5G NR) that brings a myriad of benefits, such as Ultra-Reliable Low-Latency Communications (URLLC), which effectively guarantees packet latency of 1 to 10 milliseconds while ensuring reliability with a packet error rate of 10-5 to 10-6.

Combined with multi-gigabit data rates, 5G NR technology enables true wire-like reliability and seamless mobility while maintaining stringent Quality of Service (QoS) for critical business applications that cannot tolerate any wireless issues.

At the same time, new private cellular spectrum bands are opening up around the world for 5G NR. With this new cellular spectrum, enterprises can now own and operate their own local private 5G LANs without the need for costly spectrum licenses.

However, O-RAN architecture requires dedicated cables, switches and network control boxes, which increases cost and complexity.

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A Deep Dive into O-RAN

Driven by the O-RAN Alliance, Open RAN is a standardized framework that promotes interoperability between different virtualized cellular RAN functions running on COTS hardware through standardized interfaces.

O-RAN is achieved by decomposing software from hardware, which allows RAN software to run on any general-purpose hardware platform, such as those based on Intel x86 and ARM architecture.

O-RAN seeks to create a path for the introduction of advanced RAN features and capabilities by further specifying standardized open interfaces between RAN functions based on 3GPP standards. This is achieved by leveraging programmable, open software development methods.

Ultimately, O-RAN is designed to provide additional flexibility to meet the requirements of 5G applications, such as 5G supporting vertical applications with different network requirements for performance, capacity or latency. Examples of this include Ultra-Reliable - Low Latency Communications (URLLC) applications, which are not fully supported in 4G LTE networks. This requires a flexible, software-programmable RAN architecture to adapt to various vertical applications. For example, through open programmable RAN interfaces, centralized and virtualized basebands can provide pooled virtualized network functions, dynamically allocate different resources through network slicing, and effectively create the necessary network service quality on demand to adapt to the needs of the application.

With the proliferation of fiber backhaul, there has been interest in virtualizing cellular network functions in order to follow a cloud-native operating model. O-RAN takes the idea of ​​this virtualized software model and applies it to the RAN, using common off-the-shelf (COTS) hardware to split the radio functions and run them on a distributed hardware platform. O-RAN essentially breaks down the RAN into three key software components.

• The Remote Unit (RU) performs low-level signal and radio processing as well as RF functions.
• Distributed Unit (DU), which performs packet scheduler and MAC layer functions
• The Central Unit (CU), which performs higher-level packet processing and encryption-type functions.

Since the above RAN functions have very strict latency and bandwidth requirements, very high-speed and high-quality dedicated fiber optic cabling is usually required to connect them.

For network operators, O-RAN architecture usually translates to RUs being deployed on top of cell towers or lamp posts. DUs are deployed under cell towers as so-called "baseband units" (BBUs), or can be further aggregated into "BBU hotels" or in central offices, connected to base stations via dedicated fiber. Finally, CUs can be further centralized in a regional data center similar to a cellular core network.

For indoor cellular deployments of O-RAN (such as venues), the same architectural approach is retained and the deployment looks very much like a traditional distributed antenna system (DAS). Basically, the traditional RF coaxial cables are replaced by high-quality cables such as optical fibers to directly connect multiple RU radios and deploy multiple DUs as baseband units in IDF or equipment cabinets, which are further connected to CUs located in MDF or basement equipment rooms.

Enterprise O-RAN helps you

But for enterprises, this telco-driven O-RAN model essentially means a completely separate infrastructure, just like a DAS system. With O-RAN, the cost and complexity are higher because high-end cables like fiber optics and many separate baseband units must be installed to connect all the various virtualized components.

Also, note that traditional cellular networks are made up of separate components that come from multiple vendors and are integrated by mobile network operators. While this model continues in the telecom 5G ecosystem, including the RAN, mobile core network, and orchestration layer, it does not work for the enterprise because it leaves the burden of integration to enterprise IT staff or system integrators. More importantly, enhanced 5G features such as network slicing with strict SLA requirements dictate tight integration from end to end.

Most businesses don’t want the complexity, cost, and long lead times associated with building a complex cellular network. Instead, they’re looking for an all-in-one 5G LAN system. For businesses, simplicity, affordability, and seamless integration are a must. Just look at the evolution of enterprise Wi-Fi to see why.

Wireless LAN solutions typically come as complete systems from a single vendor, including access points, controllers, and management platforms—all prepackaged and tuned to work together.

Emerging enterprise 5G LANs should follow this model.

Fortunately, new private mobile network platforms have emerged that provide both integration and the ability to disaggregate the RAN when and where needed. This means that enterprises can deploy 5G LANs in a familiar Wi-Fi manner and over time move different radio functions in software to core software systems where and when needed.

While in some cases, large enterprises with significant IT resources will embrace a telco-driven O-RAN model to achieve the highest levels of agility, the vast majority of enterprises looking to embrace 5G want an end-to-end 5G solution designed for them, not the operator.

Given the far-reaching benefits of 5G technology, widespread enterprise adoption is undeniable. But to achieve this, 5G radio access networks should be deployed as an overlay to the enterprise LAN, just like Wi-Fi networks, using existing Ethernet cables, switches, and network policies.

This approach radically reduces costs, but also fully integrates private 5G networks with existing enterprise IT infrastructure, providing a clear path for enterprises to leverage the value of 5G.