RIC in O-RAN: AI-Driven RAN Intelligent Controller Explained

Introduction: The RAN Intelligent Controller (RIC) is the brain of O-RAN’s AI/ML capabilities. RIC is divided into non-RT RIC (for analytics and policies) and near-RT RIC (for fast control). It leverages xApps and rApps to optimize traffic, interference, handovers and more. This page describes how RIC works, its architecture, use cases and integration in modern 5G network.

RAN Intelligent Controller (RIC) Architecture

The RAN Intelligent Controller (RIC) was developed to overcome the rigidity and vendor lock-in of traditional RANs (2G, 3G, 4G), where all radio, baseband, and control functions were tightly integrated in proprietary hardware. In such legacy systems, optimization, upgrades, or AI-driven automation were limited because operators depended entirely on a single vendor’s closed ecosystem.

The RIC in Open RAN introduces intelligence, openness, and programmability through standardized interfaces and AI/ML-driven control. It enables real time optimization of resources, load balancing, interference management and energy efficiency using modular apps (xApps and rApps).

This open, software defined approach allows operators to mix vendors, deploy innovations faster and achieve greater network flexibility, automation and performance compared to traditional RANs.

Image Courtesy : O-RAN Alliance

The figure depicts architecture of O-RAN including its main components and types. A1 interface is used between non-RT RIC and near RT RIC. E2 interface is used between near RT RIC and RAN nodes (i.e. O-CU & O-DU).

Non-RT RIC

• It is part of SMO (Service Management & Orchestration).
• Works on slower timescales i.e. control loops > 1 second.
• It performs policy management, analytics, ML model training, performance history, planning etc.
• Hosts “rApps” which are applications built to run in non-RT RIC. It’s main task include network wide optimization, policy preparation etc.

Near-RT RIC

• It is deployed closer to RAN (often at edge cloud or regional DC).
• It works on tighter timescales i.e. control loops between ~ 10 ms & 1 seconds.
• It is responsible for policy execution, RRM actions, reacting to fast changing radio conditions etc.
• Hosts xApps which implement functionalities like traffic steering, handover optimization, interference management, QoS tuning etc.

Conclusion: The RIC elevates O-RAN from open interfaces to truly intelligent networks. With AI/ML, feedback loops and modular app frameworks, RIC empowers networks to react, adapt and optimize continuously. For operators striving for automation, better resource utilization and scalable performance, mastering the RIC architecture is a critical step toward the future of RAN.