"The O-RAN Whitepaper 2022 - RAN Intelligent Controller"

The O-RAN Whitepaper 2022 - RAN Intelligent Controller

We are pleased to introduce our latest?The O-RAN Whitepaper 2022 (RAN Intelligent Controller) ?by Rimedo Labs. RAN Intelligent Controller (RIC) is one of the key elements in the O-RAN architecture, which allows feeding an ?external” intelligence into the operations of the radio network. It creates a platform for which the software companies could provide per-use case AI-powered algorithms to make way for, among others, radio resources usage, or procedure optimizations. This whitepaper provides an overview of the RIC, discusses its functional split into Non-Real-Time and Near-Real-Time entities along with the concept and examples of rApps and xApps.

Executive Summary

This whitepaper provides the technical discussion of one of the key components in the Open Radio Access Network (Open RAN) architecture as defined by O-RAN Alliance, i.e., RAN Intelligent Controller (RIC). RIC serves as a platform for the optimization of the radio network and radio resources and is split into Non-Real-Time RIC (Non-RT RIC), operating in the management plane, and Near-RT RIC, operating in the RAN domain. The names refer to the timescale of operation, Non-RT RIC operates in the range of minutes or hours, while Near-RT RIC operates within tens or hundreds of milliseconds. Both RICs use external applications, called rApps and xApps respectively serving as tailored algorithms for certain use cases, including radio resource management (RRM) and self-organizing networks (SON) functionalities.

First, the concept of RIC is described, together with its functional split and three control loops in the O-RAN architecture. This is accompanied by the comparison between xApps and rApps. The first chapter serves as a starting point for more details to be provided in the following parts.

Later, the whitepaper discusses the Non-RT RIC, its architecture within Service Management and Orchestration (SMO), along exemplary rApps. The discussion focuses on a specific application, for the Quality-of-Experience (QoE) prediction, where three rApps provide input for creating policies for resource optimization.

Next, the details of Near-RT RIC are addressed, which provides the possibility to manage the radio resources on a near-real-time basis using xApps. The architecture of Near-RT RIC is discussed, together with the accompanied open interface, E2, and one of the service model types, namely Key Performance Measurements (KPM).

The final part of the whitepaper provides the description of an xApp implementation example for the use case of traffic steering. The scenario setup, use case, machine learning (ML) model training, and simulation results are discussed.

The whitepaper ends with a summary and conclusions section along with a glossary of the O-RAN terms.

Contents

Executive Summary

Chapter 1.0 Introduction to RAN Intelligent Controller

• 1.1 RAN Intelligent Controller
• 1.2 Control Loops
• 1.3 xApps and rApps

Chapter 2.0 Non-Real-Time RIC and rApps

• 2.1 Non-RT RIC
• 2.2 Non-RT RIC Architecture
• 2.3 rApp Examples

Chapter 3.0 Near-Real-Time RIC

• 3.1 Near-RT RIC
• 3.2 Near-RT RIC Implementation Options
• 3.3 Near-RT RIC Deployment Flexibility
• 3.4 E2 Interface

Chapter 4.0 xApp Implementation

• 4.1 Traffic Steering Use Case Analysis
• 4.2 Considered Network Setup
• 4.3 xApp Implementation: O-RAN Traffic Steering Use Case
• 4.4 System Training
• 4.5 Simulation Results

Summary and Conclusions

Glossary

References

[1]?O-RAN ALLIANCE (o-ran.org)

[2] O-RAN.WG1.O RAN Architecture Description v03.00, “O-RAN Architecture Description”, O-RAN Alliance

[3] O-RAN.WG2.Non-RT-RIC-ARCH-TR-v01.00, ?Non-RT RIC Architecture”, O-RAN Alliance

[4] O-RAN.WG3.RICARCH-v02.00, ?Near-Real-time RAN Intelligent Controller (Near-RT RIC) Architecture”, O-RAN Alliance

[5] O-RAN.WG3.E2GAP-v01.01, ?Near-Real-time RAN Intelligent Controller Architecture & E2 General Aspects and Principles”, O-RAN Alliance

[6] ORAN-WG3.E2SM-KPM-v01.00.00, ?O-RAN Near-Real-time RAN Intelligent Controller E2 Service Model (E2SM) KPM”, O-RAN Alliance, February 2020

[7] X. Xu, C. Yuan, W. Chen, X. Tao, and Y. Sun, ?Adaptive Cell Zooming and Sleeping for Green Heterogeneous Ultradense Networks,” IEEE Transactions on Vehicular Technology, vol. 67, no. 2, pp. 1612-1621, Feb. 2018.

[8]?Dryjański, M.; Ku?acz, ?.; Kliks, A. Toward Modular and Flexible Open RAN Implementations in 6G Networks: Traffic Steering Use Case and O-RAN xApps. Sensors 2021, 21, 8173.?https://www.mdpi.com/1424-8220/21/24/8173

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To download the Whitepaper, go to?The O-RAN Whitepaper 2022 (RAN Intelligent Controller)

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Other Resources from Rimedo Labs

• The previous whitepaper:?The O-RAN Whitepaper 2021 (mailchi.mp)
• To check our blog posts on #AllThingsWireless, visit:?Blog – RIMEDO Labs
• Webinar:?A video recording from an O-RAN Webinar:?O-RAN Architecture and Use Cases – YouTube
• To download the slides from the O-RAN Webinar, visit:?slides on O-RAN Architecture and Use Cases
• Training:?Sign up for our?O-RAN System Overview ?Course.
• Poster?(High quality, printer-friendly, A3):?Subscribe to get your O-RAN Poster copy .