The shift to virtualized RAN and open RAN is creating new opportunities for carriers to shift much of their RAN hardware and software to server-based platforms and solutions based on open source software. The O-RAN Alliance and other industry groups have both developed and adopted open source solutions for significant parts of the open RAN functionality. These solutions are already seeing early deployments, and much of the industry is expecting to use software infrastructure based on open source solutions to run RAN applications.

In the past, RAN software has been largely proprietary and developed for specific hardware. Network virtualization caused a significant change in the way networks systems were designed with the use of server-based platforms and virtualized network functions. This shift was enabled by open source developments such as OpenStack that delivered a common cloud computing infrastructure software. Since the development of OpenStack, network virtualization has moved on to support cloud-native implementations with containerization and solutions such as Kubernetes. The same challenges exist for the development of open RAN and virtualized RAN software infrastructures, and the solutions have primarily been driven through open source developments.

A shift to open source for RAN applications
The new Heavy Reading "Accelerating Open RAN Platforms Operator Survey" published in May 2021 presents the results of an exclusive survey of individuals working for operators with mobile network businesses. In addition to confirming that most of the industry believe it is practical to virtualize a 5G baseband function for commercial deployment within two years, the survey also covered the software infrastructure to run RAN applications, as shown in the figure below.

Figure 1: As open RAN-based systems are designed and built, what does your organization anticipate using as the software infrastructure to run RAN applications? n=89
(Source: Heavy Reading)

When asked what their organization anticipates using as the software infrastructure to run RAN applications, 86% said their organization would use an open source solution. Almost half anticipate their organization will use a vendor-supported open source software infrastructure solution. A further 38% will build their own software infrastructure, but they will start with an open source solution. This result underlines the importance of open source solutions for the deployment of open RAN. It also emphasizes the extent to which groups such as the O-RAN Alliance are adopting open source software. The O-RAN Alliance is aligning a software reference implementation with the group's open RAN architecture and specifications.

"The O-Cloud framework [within O-RAN] for all the different split models is sitting on top of an open source project called StarlingX," said Paul Miller, CTO at Wind River, when he spoke on the Light Reading "Accelerating Open RAN Platforms Operator Survey" webinar (view the archive here). "That StarlingX project is hosted in the Open Infrastructure Foundation (formerly Open Stack Foundation). That is a Kubernetes and bare metal first approach but it uses a highly distributed architecture that enables somebody to deploy 10s of 1000s of sites and manage them from a central pane of glass. This is really recognizing the unique challenges of a virtualized RAN as a highly geo-distributed architecture."

Heavy Reading's "Accelerating Open RAN Platforms Operator Survey" focuses on why operators are deploying open RAN and which platform architectures, hardware accelerators and software and integration solutions are viewed as most important for these deployments. You can download a PDF copy here.

— Simon Stanley, Analyst at Large, Heavy Reading

This blog is sponsored by Wind River.