Open RAN Alliance (http://www.o-ran.org) is an industry initiative resulting from the merging between xRAN Forum with the C-RAN Alliance, with the objective to form a world-wide, ‘carrier-led’ effort to push more openness into the radio access network of the next-generation wireless systems. It is supported by AT&T, China Mobile, Deutsche Telekom, NTT DOCOMO, Orange, Verizon and TIM and other telco operators.
The openness of network architecture and interfaces is carried out in two main tracks:
- Defining implementation requirements by means of “profiles” defined on top of Specifications provided by the relevant Standard Development Organizations, like 3GPP, so that multi-vendor interoperability of RAN functions is ensured. This aspect involves both functional interfaces and management interfaces
- Introducing new functions and interfaces to centralize the key radio resource management functions in a RIC (RAN Intelligent Controller) interworking with the existing RAN functions (e.g. gNB-CU and DU) where customized algorithms, empowered by the adoption of Artificial Intelligence / Machine Learning techniques, can be designed and implemented as Cloud Native Applications.
Near Real Time RIC exposes RAN capability and resources towards the Management and Orchestration layer over A1, an “intent-based” interface used to instruct RAN with performance targets and Radio Resource Management policies. The new A1 interface will complement Network Management and Orchestration O1 interface providing fault-management, configuration, accounting, performance, and security (see figure).