Cloud RAN goes prime time as Nokia and AT&T prove fully virtualized capabilities
An open and programmable Radio Access Network (RAN) enables the introduction of many new capabilities for the use of 5G networks. Together with virtualization and network automation it is expected to result in significant improvements in the way Communications Service Providers (CSPs) manage their networks and deliver new services. Furthermore, it fosters innovation by supporting the introduction of advanced capabilities such as artificial intelligence (AI) and machine learning (ML). Open and programmable RAN promises benefits such as improved network performance, accelerated time-to market of new services and functions, more flexible and agile networks, and CAPEX and OPEX efficiencies.
To deliver the innovative technologies and services that will help win new business with 5G, CSPs need extreme scalability, agility to adapt to emerging 5G applications, low latency, high performance, and huge capacity, as well as new operational models in their 5G networks. It is Cloud RAN and Open RAN that are emerging as the key technologies that will enable CSPs to get 5G right.
AT&T and Nokia drive open and virtualized RAN forward - achieve fully cloudified data calls in a limited trial
The latest achievement by AT&T and Nokia is a successful end-to-end L3 data call over a fully virtualized Cloud RAN.
The over-the-air call was achieved at the AT&T facility in New Jersey, USA using Nokia’s next generation vRAN2.0 with virtualized Distributed Unit (vDU) and virtualized Centralized Unit (vCU). Testing included different data transfer profiles such as web surfing, video playback, and network speed test measurements.
“This proof-of-concept is an integral part of the joint effort by AT&T and Nokia to drive forward an open, programmable and virtualized RAN, which sits at the heart of AT&T’s 5G network evolution strategy,” said Mazin Gilbert, vice president of network automation and analytics at AT&T.
“The joint AT&T and Nokia team demonstrated the maturity of the fully virtualized Cloud RAN architecture. This is important because it paves the way for Nokia and AT&T for the next steps in the verification of Cloud RAN technology as well as further advances the development of scalable and intelligent 5G networks. The successful completion of this project also overcame challenges posed by the ongoing COVID pandemic and so the team can be proud of this joint achievement.” said Pasi Toivanen, Head of Edge Cloud Platforms BU at Nokia.
The proof-of-concept was enabled by:
- AirScale Cloud RAN vRAN2.0 baseband with vDU and vCU running in the cloud
- Fronthaul conversion with Nokia’s Fronthaul Gateway to convert and connect existing CPRI-based radios to the Ethernet-based standard eCPRI 7-2x that is the basis for interoperability specification by the O-RAN Alliance.
- Nokia 1830 Time-sensitive Packet Switch (TPS)-24 for fronthaul CPRI-RoE (Radio over Ethernet)-CPRI conversion and Ethernet transport also providing class-C sync for fronthaul
- Nokia 7250 IXR-X1 as Carrier Aggregation Switch (CAS) for switching and routing of fronthaul, midhaul and backhaul
- Commercial 5G device
AirScale Cloud RAN vRAN2.0: Both CU & DU fully cloud based
Programmability and innovation
The fully cloudified and disaggregated Cloud RAN used in the trial is optimal for Open RAN (O-RAN), splitting the base station into Radio Unit (RU), virtualized Distributed Unit (vDU), virtualized Centralized Unit (vCU) and O-RAN compliant interfaces between these elements.
The near-real time RAN Intelligent Controller (near-RT RIC) that AT&T and Nokia are co-creating in alignment with the O-RAN Alliance, has previously been tested on the same edge platform. The flexible compute resources available on the cloud platform are enabling the creation of a powerful 5G optimization platform that brings programmability to the RAN and enables AI and ML capabilities to optimize and improve system performance. The two companies are building on this successful proof-of-concept to trial advanced xApp-based RAN optimization capabilities using ML based per-UE guidance.
Flexibility and Automation
Another key benefit that Cloud RAN solutions unlock for CSPs such as AT&T, is the ability to create a uniform hardware infrastructure across their footprint. A common infrastructure will allow different RAN (and core) functions such as the CU-UP, CU-CP, and DU to be dynamically right sized to the demands of new 5G workloads as they emerge in verticals such as broadband, IoT, and URLLC. Adding automation will also allow a more graceful response to failures. Such flexibility and automation will provide customers and end user applications with a more reliable 5G network that is tailored to them. This trial is enabling AT&T to build the models necessary to enable such automation.
Fully cloudified 5G AirScale Cloud RAN
Prime time for Cloud RAN
As Phil Marshall, Chief Research Officer of Tolaga Research, said recently: “Significant progress has been made to disaggregate and virtualize radio functions, which results in greater flexibility for centralizing and distributing radio functions depending on design preferences and the availability of fronthaul resources. With virtualization maturing, 5G emerging and Cloud RAN technology advancing to deliver economic benefit, industry stakeholders are engaging - it is now prime-time for Cloud RAN.”
This means CSPs can be assured that as they build their 5G network their investment can be scaled accordingly to meet the demand of their customers and provide a platform to grow their business.
Joint effort
Nokia and AT&T will continue to collaborate in the joint 5G Cloud RAN initiative to further advance the development of open and virtualized RAN. The ongoing joint work on the near-RT RIC and an open ecosystem of applications to leverage RIC capabilities brings programmability, intelligence, and innovation to the way CSPs build 5G networks.
