The companies — Deutsche Telekom, Orange, Telefónica, TIM and Vodafone — announced their open RAN collaboration earlier this year, initially without TIM, saying at the time they planned a speedy implementation. TIM has already claimed the first deployment, in the city of Faenza.
But now a new document from the five show the details of the plans, and it sets out stringent requirements for vendors.
“Energy efficiency is a global requirement encompassing various domains of Open RAN,” they say. “Hardware should be the most energy efficient as possible, starting with radio transmitters, but also considering RAN infrastructure, where energy efficiency will be a criterion in the choice of accelerators.”
They add: “Vendors should also implement features to reduce the energy consumption in both networks and devices in low load situations.”
They also demand high security, noting: “Security is a global priority for the operators requiring strict policies and features across all entities of the open RAN network, which raises new challenges due to the multiplication of vendor solutions and open interfaces.”
But what will focus the minds of open RAN vendors is the speed the operators want to move. “In terms of timeframe, the operators wish to ensure the readiness of open RAN solutions for large scale network roll-out from 2022 onwards,” it reveals.
And not for just a few test installations: “Macro deployment is identified as the primary target for the operators.”
So far the five have moved carefully into open RAN, which is seen as away of releasing them from being tied in to Ericsson and Nokia as radio access network vendors, especially now that they are restricted from buying from Huawei or ZTE in many parts of the world.
The five operators say they “consider further standardisation is required” and they do not plan to define any open RAN standards. “Standardisation will be subject to the established standard-setting bodies such as the O-RAN Alliance.”
They say that “to become a competitive alternative to traditional RAN, the operators require solutions that will not compromise on network quality, security, high energy efficiency, as support for 4G and 5G …, efficient RAN sharing and legacy band support.”
They want flexibility “to match various network topologies” including centralised and virtual RAN deployments. They want to use edge or regional cloud for centralised RANs.
“Small cell deployment for both outdoor and indoor scenarios is being targeted with different architectural splits and centralisation options. Indoor deployment does also include a multi-operator scenario with shared or dedicated infrastructure,” say the five operators.
“Efficient RAN sharing management is required to allow sufficient independence between operators.”
Though open RAN is aimed at 4G and 5G, operators need to continue to operate 2G and 3G, so there will need to be “inter-operability between 2G/3G baseband units and RUs [radio units], based on proprietary interfaces, since no open interface has been specified successfully.”
They want a Kubernetes-based open cloud platform supporting the necessary RAN software.
The five say that “vendors should provide a comprehensive set of features for open RAN solutions to be on par with the best-in-class traditional RAN networks” and they should “minimize any potential gaps in [the] features roadmap of interest for Europe”.
They add: “RAN features should support high performance in terms of user throughput, capacity and latency”.
