Open RAN: 2020 and Beyond

fronthaul, E2 for intelligent control of RAN nodes, A1 for AI/ML based policies for RAN control, and a uniform and consistent interface O1 for managing RAN nodes. Obviously, the interfaces need to be well defined and fully interoperable for a multi-vendor solution to interwork properly. The O-RAN Alliance working groups focus on providing appropriate interoperability test specifications for these interfaces. Additionally, Radisys was instrumental in forming the Test Integration Focus Group (TIFG) within the alliance to work on end-to-end interoperability testing and to provide additional test cases for validating O-RAN solutions. Test equipment vendors are actively participating in the O-RAN Alliance to realize this goal.

Hardware-software decoupling, open hardware and cloudification

With a clear focus on achieving the benefits of cloud-hosted RAN network nodes, O-RAN has a working group dedicated to the cloudification and orchestration aspects that allow hardware and software decoupling. There is also standardization happening to abstract software implementations from vendor-specific hardware acceleration technologies.

Uniform and consistent management plane across all nodes

A main pain point for operators is dealing with network management systems and interfaces that are proprietary and vendor specific. O-RAN solves this problem by providing a common and unified management system approach and a common management interface (named O1) to manage RAN elements. The Alliance defines data models that all vendors can adhere to in order to make life a lot simpler for operators and ensure visibility and consistency in network management aspects.  

Intelligence, customization and automation in RAN operations

O-RAN architecture makes it possible to centralize, monitor and control RAN operations and provides for applying operator-specific policies and tailor-made algorithms. This is done using the RAN Intelligent Controller (RIC) nodes, providing a new degree of freedom. Previously, operators had to use hard-coded logic embedded in closed proprietary implementations and had limited control through configuration settings. The approach of using RICs is a sea change and is a powerful tool for operators to control RAN operations in a fine-grained manner.

The O-RAN Alliance standardization work is going full steam ahead with the view to enable vendors to create and update their Open RAN products in the market and to ensure end-to-end deployment readiness. So far in 2020, there have been 20 specifications released from the O-RAN Alliance, with many more planned for the remainder of this year.

Enabling a smart network

The role of the RAN Intelligent Controller (RIC) is central to O-RAN-based architecture. Both real-time and non-real-time RICs constitute an intelligence layer, operating at the network layer, to optimize each service and use case supported by the operator. With the metrics generated within the radio access network, RICs can apply AI/ML techniques and sophisticated algorithms to achieve automated network monitoring and control. In addition, the network management and orchestration layer make it possible to achieve a level of automation that was impossible before. 

A recent Forbes article explored the interesting possibilities of how the smart networks of the future will serve various advanced use cases ranging from movie streaming to