Automation with AI and ML-based Applications in Open Radio Access Networks (ORAN)

Evolution of Open and Disaggregated Networks: a transformative period.

Over the past four years, there has been a significant shift towards open and disaggregated networks, driven by initiatives led by O-RAN ALLIANCE and TIP’s OpenRAN project, in collaboration with mobile network operators and other industry vendor forums. While there is now a wider array of choices in hardware components for an Open RAN, the software aspects are still evolving.?

A critical element of O-RAN ALLIANCE architecture is the RAN Intelligent Controller (RIC), which allows for the interoperability and portability of software applications interfacing with the radio network. Through the application of AI/ML techniques, it assesses, diagnoses and learns to optimize the performance and resource utilization of radio network elements. For MNOs, this evolution brings the promise of substantial future benefits, such the ability to dynamically adapt radio access at each site, optimize spectrum usage, achieve greater energy efficiency, and enhance coverage and capacity to accommodate fluctuations in customer demand.?

The concept of Open RAN is explained in below diagram:

Open RAN = Virtual RAN + Software-Defined RAN

You can watch a video to know more about ORAN with RICs by Dr Rakesh Misra.

https://youtu.be/DYqAOgyyoic?si=he_qaiY2s7iWQH3s

The RAN Intelligent Controller (RIC) is a critical component of Open RAN. It controls and optimizes the radio access network (RAN), the part of the cellular network that connects mobile devices to the core network. The RIC does this by running xApps and rApps.

xApps are near-real-time applications that control the RAN in real-time. Users can utilize it to optimize performance, enhance reliability, and introduce new features. rApps, non-real-time applications, analyze data, and generate policies for the RIC. They can improve network planning, identify problems, and troubleshoot issues.

How do xApps and rApps get hosted with RIC?

Two types of RIC components are known as non-real-time (non-RT) and near-real-time (near-RT). Each of them is responsible for managing distinct functions within the RAN. The non-RT RIC oversees events and resources that require a response time of one second or longer. On the other hand, the near-RT RIC handles events and resources that demand a faster response, as quick as 10 milliseconds (ms). Typically, organizations deploy the non-RT RIC centrally, whereas they can deploy the near-RT RIC centrally or at the network edge.

The Non-RT RIC is responsible for managing radio resources, optimizing higher-layer procedures, and implementing policies within the RAN. It supports the near-Real Time RIC functions by providing guidance, parameters, policies, and AI/ML models to achieve non-real-time objectives. It includes service and policy management, RAN analytics, and model training for near-Real Time RICs. Deployed centrally within the service provider network as part of the SMO Framework, it controls RAN elements and their resources in a non-real-time manner using specialized rApps.

On the other hand, the Near-RT RIC operates in near-real-time and focuses on optimizing, controlling, and monitoring O-CU and O-DU nodes within a timeframe of 10 milliseconds to 1 second. It depends on the policies of the non-RT RIC and uses models calculated or trained by the non-RT RIC. Its main task is managing radio resources (RRM) and performing optimization actions that usually take ten milliseconds to one second to finish. Specialized xApps communicate policy feedback to the Non-RT RIC.

RIC and xApps/rApps play a crucial role in Open RAN by enabling enhanced flexibility, agility, and innovation within the RAN. These components empower operators to tailor their networks according to their unique requirements, resulting in improved performance, cost savings, and the introduction of novel services.

Benefits of RIC and xApps/rApps in the Context of Open RAN

Flexibility and Vendor Neutrality

Open RAN promotes interoperability and vendor neutrality by decoupling hardware and software components. RIC acts as a central orchestrator and controller in the RAN, providing a unified interface for managing and coordinating various network elements. xApps/rApps run on the RIC, enabling specific functions and services. This flexibility allows operators to choose different vendors for different components, promoting competition and innovation in the market.

Scalability and Service Agility

RIC and xApps/rApps enable scalability and service agility in Open RAN deployments. With the centralized control provided by RIC, operators can dynamically allocate network resources, optimize radio performance, and adapt to changing network conditions in real-time. Operators can develop and deploy xApps/rApps independently, introducing new services and functionalities quickly without needing complex and time-consuming network upgrades.

Artificial Intelligence (AI) and Automation

RIC and xApps/rApps leverage AI and automation capabilities to enhance network management and optimization. AI algorithms can analyze vast amounts of data collected from the RAN, making intelligent decisions and automating network processes. For example, xApps/rApps utilizing AI can optimize coverage, manage interference, perform predictive maintenance, and improve energy efficiency, among other use cases. These capabilities help operators reduce operational costs, enhance user experience, and improve network performance.

Innovation and Ecosystem Development

RIC and xApps/rApps foster innovation and ecosystem development in the Open RAN ecosystem. By providing a standardized interface and framework for application development, they encourage third-party developers and vendors to create new xApps/rApps that address specific network requirements and use cases. This open and collaborative approach promotes the development of a diverse ecosystem with a wide range of innovative solutions, leading to accelerated innovation, increased competition, and, ultimately, better services for end-users.

Enhanced security

The RIC can be more secure than traditional hardware-based controllers because it can be updated and patched more easily. It is essential because RANs are potential targets for cyberattacks. Reduced costs: The RIC can help operators to reduce costs by enabling them to use open, interoperable hardware and software. It can lead to lower procurement costs, as well as lower maintenance and upgrade costs.

Conclusion

RIC and xApps/rApps are crucial components of Open RAN deployments, enabling flexibility, scalability, service agility, AI-driven optimization, and ecosystem development. These empower operators to build and manage open, vendor-neutral, and programmable networks that adapt to evolving needs and deliver enhanced services to end users. Soon, innovation will be around RIC, xApps/rApps, and vendors will fiercely compete to unlock new services leveraging these capabilities.