RAN Intelligent Controller (RIC)

What Is a RAN Intelligent Controller (RIC)?

A RAN Intelligent Controller (RIC) is a crucial software-defined element within the Open Radio Access Network (Open RAN) architecture. It plays a pivotal role in controlling and optimizing Radio Access Network (RAN) functions. The RIC is instrumental in the Open RAN disaggregation strategy, facilitating multivendor interoperability, intelligence, agility, and programmability in radio access networks. Additionally, the RIC enables the integration of third-party applications, which automate and optimize RAN operations on a large scale. This integration supports innovative use cases, reducing mobile operators’ total cost of ownership (TCO) and enhancing customers’ quality of experience (QoE).

Two Types of RIC

The O-RAN Alliance defines two types of RIC:

The non-real-time RIC:

• This is the hosting environment for rApps.

• It is typically centrally located within the radio access network.

• It facilitates non-real-time actions that exceed one second.

The near-real-time RIC:

• This is where xApps are hosted.

• The near-real-time RIC is usually situated in more distributed parts of the RAN, such as within telco edge cloud or regional clouds, but it can also be centrally located.

• It enables actions that take between 10 milliseconds and one second to complete.

While these two types of RIC have distinct primary functions, they are capable of communicating with each other. The non-real-time RIC is integrated into operators' Service Management and Orchestration (SMO) Framework, acting as the controller for higher-level activities within the RAN. It directs the near-real-time RIC to orchestrate RAN workloads to meet customer requirements. Many consider the non-real-time RIC as an evolution of the Self-Organizing Network (SON) due to its orchestration and management capabilities. In contrast, the near-real-time RIC is responsible for executing critical RAN functions.

How Does the RIC Function?

The RIC operates through two main components: non-real-time and near-real-time. The non-RT RIC is integrated into the operator’s centralized Service Management and Orchestration (SMO) Framework, in accordance with the O-RAN Alliance standards. Through specialized applications known as rApps, the non-RT RIC manages RAN elements and their resources with a response time exceeding one second. It leverages network data, performance metrics, and subscriber information to offer AI-driven recommendations for network optimization and policy guidance. These recommendations are then passed on to xApps, which run on the near-RT RIC. The near-RT RIC, located within telco edge or regional clouds, executes network optimization actions that typically require between 10 milliseconds and one second to complete.