t Network SW Vendor 2 Open RAN software Commercial off the Shelf (COTS) Servers Open RAN hardware Figure 12.11 - A deployment based on O-RAN swapping RAN software vendor [image credit: Sanya] Figure 12.12 and Figure 12.13 further illustrate this concept, where O-RAN allows tremendous flexibility due to the ability to swap out hardware and software vendors. 5G Open RAN Service Service Service Service Service Service Service Deployment Model with CU, DU, and RRU Transport Network SW Vendor 2 Open RAN CU Commercial off the Shelf (COTS) Servers Open RAN DU Open RAN RRU Figure 12.12 - A deployment based on O-RAN with central and distributed units [image credit: Sanya] Understanding O-RAN Figure 12.13 illustrates how the integrators manage the O-RAN infrastructure. This adds further flexibility for managing O-RAN deployments: Open RAN Service Service Service Service Service Service Service Integration Models Managed by Integrator Transport Network Vendor 2 CU Software Vendors Open RAN CU Commercial off the Shelf (COTS) Servers COTS Vendors DU Software Vendors Open RAN DU COTS Vendors Integrator Manages integration Open RAN RRU RU Vendors Figure 12.13 - A deployment based on O-RAN integration models [image credit: Sanya] This model can swap out elements as improved parts or replacements are needed due to the global supply chain crisis during the pandemic. AT&T openly shared the impact of the semiconductor industry delays and the resulting impact on RAN equipment, as can be read here: https://www sdxcentral.com/articles/news/att-ceo-a-little-skittish-about-5g- ran-supply-chain/2021/04/. Next, let us look at the O-RAN infrastructure management and operating cost models. Managing O-RAN infrastructure The O-RAN specification presents a standardized architecture to 5G service providers. It eases the management of the O-RAN network infrastructure by virtue of minimal dependency on any proprietary hardware, fostering innovation among the network application designers. Figure 12.14 shows that O-RAN can reduce the network's oper