Open RAN (Radio Access Network), or O-RAN, stands at the forefront of the RAN revolution and is the latest of several generations of RAN technology that have evolved since the beginning of the cellular network. O-RAN aims to bring agility and the benefits of “cloudification” to the RAN. This blog, the first of a series on O-RAN, provides a high-level introduction to O-RAN and its benefits.
Originally implemented using a closed architecture, the RAN traditionally locked operators into the same vendor for both their radio and their baseband units. In contrast, O-RAN benefits operators through its emphasis on intelligence and on open interfaces and standards, which encourages multivendor deployments and facilitates customization to suit individual operators’ needs. Openness and intelligence are its core principles, as defined by the O-RAN Alliance.
O-RAN has been picking up steam within the industry for the past few years. With its goals of lowering costs; bringing more vendors into the fold; strengthening supply-chain security; increasing deployment flexibility; and encouraging innovation, O-RAN is poised to be a massive game-changer for mobile network operators.
O-RAN is literally about opening the interfaces between its main components, namely the Radio Unit (RU), Distributed Unit (DU), and Centralized Unit (CU). Both the CU and DU represent what was originally known as the Baseband Unit (BBU), which traditionally linked with the RU at the base of a tower. Opening these interfaces allows operators to pair RUs from one vendor with a BBU from another, or vice versa, essentially enabling multivendor RAN deployments and preventing vendor lock-in. For operators their win is a best-in-class RAN solution, handpicked to meet their needs.
O-RAN usually refers to both Open RAN and sometimes virtualized RAN (vRAN). vRAN decouples the RAN software from the hardware. The BBU functions are moved onto commercial-off-the-shelf (COTS) or general-purpose, processor-based platforms. This enables the BBU to be relocated from the cell site to a data center. This is a paradigm shift that enables operators to add intelligence levels not previously available on the hardware. With vRAN, operators can transform their networks into something more flexible, automated, capable of self-learning, and cost-effective.
Although O-RAN is in its infancy and has its fair share of challenges, clear benefits and use cases have emerged. Lowering CAPEX and OPEX remain significant drivers, a benefit O-RAN delivers through increased vendor competition and various network system improvements, such as virtualizing the BBUs. Furthermore, virtualization allows for quicker deployments and capacity scaling, as well as faster service rollout, accelerated innovation, and a shorter time to market. Operators also benefit from greater supply-chain security because open interfaces allow for a larger pool of vendors and easy replacement of RAN components.
This is not to downplay the challenges ahead for O-RAN. Disaggregating the RAN was challenging enough, but integrating the multivendor components into a high-performing RAN also presents challenges. However, the benefits and potential O-RAN brings to the table are too great to ignore. We’ll dive deeper into the challenges in a future blog.
Look out for Part 2 of this series, where we’ll dive into Fujitsu’s Open RAN solution and explain why we believe it’s the most viable option for 5G infrastructure.