Open RAN (O-RAN)

Open RAN (O-RAN) is an ongoing shift in mobile network architecture that enables service providers to use non-proprietary subcomponents from a variety of vendors. Open RAN, or Open Radio Access Networks, is made possible by a set of industry standards that telecommunications vendors can follow when producing related equipment. Open RAN supports programmable, intelligent, disaggregated, virtualized and interoperable functions. 

Specifically, the proprietary Remote Radio Head (RRH) and Baseband Unit (BBU) are now decomposed into Radio Units (RUs), Distributed Units (DUs), and Centralized Units (CUs), many of which can be virtualized or containerized change. The interface between these new components is open and interoperable. 

The O-RAN Alliance defines the specifications of all Open RAN components and the interfaces between them. Founded in 2018, the O-RAN Alliance is a progressive global community of mobile network operators, manufacturers, suppliers, and research and academic organizations working in the global telecommunications sector. 

Generally, Open RAN refers to a decentralized radio access network with open interfaces between network components from multiple vendors, while O-RAN refers to the O-RAN Alliance and its work.