Deutsche Telekom-led consortium demos multi-supplier non-real-time RAN optimisation

Just as rivals across Europe were announcing key evolutions in their roadmaps for the advancement of open radio access network technology in their newest networks, comms giant Deutsche Telekom has revealed an ongoing commitment to the development of Open RAN technology, by announcing details of a multi-supplier trial around programmable radio access networks that it said demonstrates the potential of a non-real-time RAN Intelligent Controller (RIC) and a third-party RAN applications (rApp) concept to automate and optimise disaggregated RAN.

The RIC, a software-defined component of the Open RAN architecture, is responsible for controlling and optimising RAN function behaviour, and enables fast onboarding of rApps that automate and optimise RAN operations at scale. It also supports innovative use cases while providing lower introduction time and ultimately lower total cost of ownership, as well as enhancements to customers’ quality of experience (QoE).

Specifically, the telco and partners AirHop, Juniper Networks, VIAVI Solutions and VMware have been working on a non-RT RIC project that brings intelligence, agility and programmability to disaggregated radio access networks and enables rApps that can perform closed-loop automation and optimisation of RAN elements and resources.

To date, the partners have completed a RAN closed-loop optimisation proof of concept (PoC) in Deutsche Telekom’s lab environment in a multi-supplier setup based on specifications from orchestration, management and network automation, and edge computing services platform ONAP and RAN operators’ alliance O-RAN. Closed loop rApp algorithms were onboarded and deployed on partners’ Non-RT RIC.

During the PoC, partners successfully executed two use cases: physical cell identifier (PCI) optimisation focused on the detection and resolution of PCI confusion and collision scenarios; and energy savings for dynamic multi-carrier management (ESMC) using an artificial intelligence and machine learning (AI/ML) model, trained to determine the optimum time to enable and disable sleep-mode on capacity cells to save energy while maintaining user quality of experience.

Initial tests were performed in a real end-to-end lab setup using a small O-RAN network to validate end-to-end configuration and performance management integration for a real network environment. Most tests were executed on a more complex network setup using an O1 network emulator (RIC tester) to validate rApp logic and stress test the RIC components to benchmark the various solutions.

As part of the setup, Deutsche Telekom provided a self-developed SMO framework along with a Non-RT RIC offering based on the O-RAN SC Non-RT RIC. Juniper Networks and VMware integrated their Non-RT RIC products into DT’s SMO framework while AirHop integrated two rApps for PCI optimisation and ESMC as each Non-RT RI VIAVI provided their RIC tester to emulate the O1 interface.

However, Deutsche Telekom cautioned that the multi-supplier integration of Non-RT RIC, rApps and SMO introduces challenges that must be addressed, and that the multi-supplier framework presents integration issues to solve.

However, the telco said the PoC has also shown from a high-level perspective that the adoption of the SMO, Non-RT RIC and rApp framework is promising in how it allows for the decoupling of optimisation algorithm development, the supporting platform development and the system integration, so that components from different parties can form a truly disaggregated RAN optimisation concept.

“With this PoC, we set out to assess the technical integration complexity of the components delivered by each party, the level of customisation required, to gauge the maturity of products and to identify potential future standardisation requirements,” said Petr Ledl, vice-president and head of network trials and the integration lab at Deutsche Telekom (DT).

“At DT, our primary focus is always on driving innovation to support the best customer experience. The RIC and rApps are key to programmability, automation and optimisation in radio access networks. Taking the learnings from this successful trial, we will now continue the work with our ecosystem partners to accelerate Non-RT RIC/rApp development towards production readiness.”

A detailed outline of these challenges, as well as customisations and future standardisation requirements, plus areas of further focus, are detailed in a trial White Paper.