One important aspect of O-RAN is the ability to detect and manage conflicting interactions between multi-vendor rApps or xApps on RIC platform without any degradation of network performance, generally labeled as “conflict management”. For example, Energy Savings and Traffic Steering use cases have very different goals and they optimize very different sets of parameters but could impact the functionality of each other.
An equally important opportunity is the coordination and cooperation between applications to provide service providers the flexibility to deliver new services and improved user experiences with greater agility and ease. For example, if the Energy Savings and Traffic Steering use cases cooperate with each other, they could jointly help save energy without any impact on the service quality. In the recent National Telecommunications and Information Administration (NTIA) RIC Forum, Juniper Networks, in partnership with Vodafone, AirHop, Rimedo Labs, and Keysight demonstrated multi-vendor rApp/xApp coordination with Energy Savings rApp and Traffic steering xApp and achieved 25% energy savings.
Diving into the NTIA RIC forum multi-vendor rApp/xApp coordination demo
The key objective of this demo was to showcase a real-world deployment where different use cases/apps from different application vendors can co-exist and cooperate with each other to achieve higher network performance and gains as compared to the impact of an individual application.
Another important goal was full adherence to open radio access networks (O-RAN) specifications and utilizing interfaces that are fully standards-based, rather than defining any vendor-specific extensions. O-RAN Alliance has made significant progress in standardization with highly mature O-RAN specifications and interfaces. Juniper, Rimedo, AirHop, and Keysight worked together to design the end-to-end use case flows based on standardized O1/A1/E2 interfaces and the relevant YANG models, E2 Service Models. AirHop, and Rimedo applications used Juniper’s O-RAN compliant Non-RT RIC R1 APIs and Near-RT RIC APIs to consume the RIC platform services and the O-RAN interfaces for their use cases.
An important pre-requisite in replicating a real-world scenario was real network data and Vodafone provided access to an anonymized real network topology along with the performance data from this large commercial cluster. Keysight provided their RICTest solution to emulate the RAN environment based on the real-world network data provided by Vodafone. Keysight RICTest emulates UEs (User Equipment), cells, nodes, control/user plane events and supports O-RAN E2 and O1 interfaces.
As part of the demo, Juniper provided its AI-Enabled Non-RT RIC and Near-RT RIC platforms, which were incubated in Juniper Beyond Labs and are now commercially available. Both the Juniper Non-RT RIC and the Near-RT RIC are based on a cloud-native microservices architecture and are fully compliant with O-RAN specifications and interfaces. They also support open APIs (R1 and RICAPI) for integration with any third-party O-RAN-compliant xApps or rApps, giving network operators greater flexibility and choice of suppliers. While the focus of this demo was the cooperation of multi-vendor applications through RIC platform services and O-RAN standards, Juniper RICs also provide conflict management and mitigation services to help prevent conflicts between applications.
AirHop implemented Dynamic Multi-Carrier Energy Savings Management rApp on top of Juniper Non-RT RIC platform. Service providers experience varied levels of service demand through the day and this rApp enables energy consumption to dynamically adapt to the mobile network service demand.
Typically, in any multi-carrier deployment, there is a coverage carrier with the ability to service broad area of coverage at some level of capacity. There are also additional capacity carriers that can handle the traffic demand by balancing the traffic load across the different carriers. AirHop’s Energy Savings rApp leverages AI-based learning and RAN programmability to predict when to turn RAN elements OFF/ON in the capacity carrier to minimize energy consumption. For example, the rApp can turn off one of the capacity carriers if the coverage carrier is not loaded. Also, if traffic starts to increase and coverage carrier becomes overloaded, the rApp can move the capacity carrier out of energy saving state to handle the increased traffic.
Traffic steering allows service providers to distribute network traffic between cells, for example, to equalize load or separate QoS flows. The traffic steering application is required to offload users to neighboring cells before any Energy Savings application can switch off the cells. Rimedo Labs implemented Traffic Steering xApp on top of Juniper Near-RT RIC platform. This app associates users with cells based on multiple factors, including: radio conditions, cell load, cell types, service type/QoS profile, per-user, per-slice association, etc. and the cell energy status.
The traffic steering application supports both service-based traffic offloading and load balancing. For example, in a network with a highly loaded macrocell and underutilized small cell, with service-based offloading the mobile broadband users can be offloaded to the small cell and the voice users are served by macro cell. With load-balancing approach, the load can be shared between the macro cell and the small cell. AirHop Multi-Carrier Energy Savings Management rApp and Rimedo Labs Traffic Steering xApp work in tandem to ensure that energy savings are achieved without impacting the user QoS.
Achieving energy savings of up to 25% with 99.999% accessibility
The demo successfully showcased cooperative multi-vendor applications (AirHop’s Energy Savings rApp & Rimedo’s Traffic Steering xApp) running on commercially available Non-RT RIC and Near-RT RIC platform from Juniper Networks. The interaction and the cooperation between AirHop’s Energy Savings rApp and Rimedo’s Traffic Steering xApp was achieved with E2SM-CCC’s (O-RAN E2 Service Model Cell Configuration and Control) inherent design principles.
The energy savings actions requested by AirHop Energy Savings rApp toward the candidate cell simulated by Keysight RICtest triggered E2SM-CCC notifications towards Juniper Near-RT RIC/Rimedo’s Traffic Steering xApp. Upon the receipt of this notification, Rimedo’s xApp started offloading the remaining users from this candidate energy saving cell to neighboring cells to minimize and eliminate any potential service impact. Once all the users were offloaded, the cell was set to energy savings state.
In terms of results, all the capacity carriers achieved energy savings of 25% with 99.999% accessibility based on the Vodafone anonymized dataset, as simulated by the Keysight RICtest. This is a great example of how service providers can achieve energy savings, while delivering a flawless experience.
Conclusion
There are many industry-wide learnings from this engagement. The demo highlights the importance of cooperation between applications as well as the importance of having well-defined standards, such as E2SM-CCC, to enable this cooperation. O-RAN specifications are highly mature and the availability of commercial grade RIC platforms like Juniper’s Non-RT and Near-RT RICs bring quantifiable benefits to O-RAN deployments today.
