Over the past few quarters, open RAN has made significant headway and is progressing toward performance parity with traditional RAN systems.
As outlined by the Open RAN MoU in February 2023, "The technology gap between traditional RAN and open RAN is closing. Significant open RAN deployments are already visible in markets such as the U.K. and North America, facilitated by government support."
Open RAN systems for macro use cases in brownfield networks are expected by the end of 2023 or beginning of 2024. However, it's the radio intelligent controller (RIC) that's the ultimate goal and game changer — with improved programmability, automation, agility, interoperability, and innovation.
The RIC enables the onboarding of third-party applications that automate and optimize RAN at scale: rApps for tasks over 1s that sit in the non-real-time RIC and xApps for tasks between 10ms and 1s hosted in the near-real-time RIC (see figure below).
Mobile operators explore multiple use cases for rApp/xApp:
- Efficiency: massive MIMO, coverage and capacity optimization, interference management, traffic steering, anomaly detection
- Sustainability: energy efficiency
- User experience: QoS/QoE optimization, SLA assurance, precise location positioning
Maturing the RIC is critically important to meet mobile operators' requirements. The O-RAN Alliance made great strides in 01, A1, and E2 interface specifications, but more work needs to be done across various domains of the RIC ecosystem:
- Near-real-time RIC scalability
- Testing and integration of various rApps/xApps from multiple vendors
- Conflict resolution between xApps and rApps
- rApp/xApp portability
Accelerating RAN Intelligence in the 5G (ARI-5G) Consortium: Goals and Partners
Launched in August 2022 for an 18-month period, the ARI-5G Consortium focuses on key foundational use cases: energy efficiency, massive MIMO, coverage, and interference. The consortium shows how a collaborative ecosystem will speed innovation, bring new open RAN products to mobile operators, and improve development cycles.
Led by the Telecom Infra Project (TIP), the ARI-5G Consortium includes Accelleran, Amdocs, AttoCore, BT, and VIAVI Solutions, and is one of the key initiatives backed by the U.K. government's Department for Digital, Culture, Media and Sport (DCMS) to speed up the deployment of open RAN products for U.K. mobile networks. ARI-5G partners' roles are as follows:
- Accelleran provides the RIC platform and leads the energy management workstream.
- Amdocs steers the coverage and capacity optimization and massive MIMO optimization workstreams and provides the required xApp.
- AttoCore provides the 5G Standalone (SA) core.
- The consortium uses BT 5G testbeds at the TIP Community Lab in Adastral Park.
- VIAVI supplies the E2 simulator/RIC test and leads the interference management workstream.
How ARI-5G can enhance efficiency with improved massive MIMO
Massive MIMO is crucial for macro deployments in dense areas to deliver a superior 5G user experience — making it a key request from mobile operators before deploying open RAN systems at scale. Reaching massive MIMO performance parity with traditional integrated RAN equipment, or even outperforming them, is mandatory. New massive MIMO technologies bring strong improvements in throughput, latency, and efficiency with beamforming as a key enabler.
The massive MIMO xApp developed by Amdocs focuses on coverage and capacity optimization for the grid-of-beams (GoB) MIMO operation mode. Each beam is associated with a unique synchronization signal block beam (SSB). The xApp dynamically optimizes beam shape and spatial distribution with algorithms leveraging signal quality, traffic, and user location.
The xApp uses multiple data collected via E2 and 01 interfaces:
- Cell and site configuration data
- Number of successful handover executions per beam pair
- Number of successful intra-NRCell SSB beam switch executions
- Other cell-specific non-real-time performance measurements
The massive MIMO xApp delivers improved coverage for SSB, including vertical coverage, which is often a pain point for mobile operators in high-rise buildings.
Amdocs' role in use case developments and collaboration in an open RAN ecosystem
Amdocs leverages its knowledge and skillset in network optimization and adapts it to the requirements of open RAN, and specifically the RIC. It brings to the ARI-5G consortium the algorithms and deep multivendor understanding that is embedded in Amdocs' Network Optimization Suite.
With open RAN, Amdocs evolved to support rapid integration of multivendor apps into third-party network infrastructure, including the RIC. In particular, Amdocs adapted its CI/CD pipelines to meet the requirements of the ARI-5G ecosystem.
In the continuous deployment phase, xApps are tested before moving to production and deployment. If test scenarios fail, the xApp goes back to the development and quality assurance phase. In successful test scenarios, the xApp goes to the external repositories of ARI-5G partners in production mode.
The open CI/CD process can be leveraged during xApps upgrades and more broadly during xApps life cycles. It can also automatically test the impact of new RIC releases on xApps and the portability of xApps. As mentioned, conflicts between apps are a key concern for mobile operators. With open RAN CI/CD processes, it's possible to test the interactions between several apps, detect potential conflicts, and mitigate them.
For more information visit: www.amdocs.com/products-services/open-ran-automation
Foundation for the future
RIC along with AI/ML technologies will bring intelligence to the RAN. Mobile operators expect the RIC to deliver granular control on RAN infrastructure with a new automation approach. It will improve asset utilization, enable new services, and accelerate innovation in open ecosystems.
This is where the ARI-5G Consortium plays a crucial role in laying the foundations for multivendor RIC deployments. It focuses on critical use cases, such as the one supported by Amdocs, and delivers a testing framework for fast onboarding of new applications and new partners.