Learn about Open RAN, how it differs from traditional RAN, and examine the high-level technical details that will enable it to function moving forward.
By Jeremy Cook
Throughout the world, more data is being distributed wirelessly. Cellular networks have transformed over the last 20 years to support various degrees of network size, complexity, throughput, and security. With the era of 5G right on our doorstep, these networks are becoming increasingly vast and complex.
This expansion has created a growing need for rigorous performance upgrades, network management optimization, cost reduction, and marketplace competition. This article introduces Open RAN and examines the high-level technical details that will enable it to function down the line.
What is Open RAN?
Open RAN (Radio Access Network) is a fundamental movement towards a modern wireless network architecture that utilizes open hardware, software, and the interfaces of wireless cellular networks. Open RAN's primary purpose is to enable aggressive network innovation, better network services, and foster a multi-vendor environment. With traditional RAN infrastructure, participation in the marketplace requires a full-stack network aggregation of the proprietary hardware, software, and interfaces required to run a cellular network, all of which demand high development and management costs.
What is Open RAN Disaggregation?
Open RAN aims to disaggregate ownership of a full-stack network. This means enabling the interoperability of all network components, such as hardware, software, interfaces, network security, automation, and more. Ultimately, Open RAN aims to provide greater flexibility and agility for service providers to deploy a network.
A typical, traditional RAN requires that service providers architect their service utilizing proprietary hardware, effectively locking the provider into only using devices available from that hardware manufacturer. While this may be an astute business strategy for the hardware vendor, it shackles innovation and creates silos in which network technology exists.
Types of RAN: Traditional RAN vs. Open RAN
Let's consider an example. Say Company A, a service provider, relies on Company B to provide them with the EPC Core of their network. They're restricted to utilizing whatever proprietary interface is compatible with that EPC Core. Subsequently, the Central Units (CUs) of the network must be compatible with the Core's interface.
Even further down the communication chain, the network's Base Band Units (BBUs) must also interface with the same CUs. Lastly, the Radio Units (RUs) that sit on the cellular towers, of course, must interface with the network's BBUs. Due to the propriety nature of each component in the network's "stack," whether it be the hardware, software, or interfaces, Company A is essentially committed to relying on the entire stack from a single vendor. This reality is referred to as Vendor Lock-In.
The goal of Open RAN architecture is to reduce vendor lock-in and spur innovation in various areas within the network. One implementation of Open RAN architecture is vRAN (virtual RAN), which functionally mimics traditional RANs. But there are fundamental differences: vRAN utilizes Commercial Off the Shelf (COTS) Distribution Units (DU) to function as a software-driven VDU (Virtual Distribute Unit), which is the functional alternative to a traditional BBU. These VDUs utilize VNF (Virtual Network Function) to emulate traditional BBUs that use software alone.
Subsequently, the VDU interfaces with a COTS Virtual Core Unit (VCU), an alternative to the traditional CU. Both the VDU and VCU are software-driven, and, most importantly, not limited to a single manufacturer. Therefore, the interface and hardware aren't "locked" into a specific manufacturer. Instead, the software that manages the vRAN in this example functions as the traditional BBU and CU, allowing Company A to be much more flexible and agile with its network management.
Conclusion
There are many facets to Open RAN architecture fundamentals. The RU-to-Core hardware example highlighted in this article is only a tiny technical facet of the more significant industry push towards network disaggregation. Open RAN fundamentals are already being implemented to accelerate the pace of 5G network deployments, and they'll allow future generations of networks to evolve more quickly and efficiently than ever before.