Cloud RAN: Deployment Focus and Standardization

As of June 2021, Ericsson updated its Cloud Radio Access Network (RAN) solution to include mid-band spectrums and massive Multiple Input Multiple Output (MIMO) capability, which paves the way towards providing more comprehensive and highly performed cloud-native virtualized network services to cover widely expanded use cases in both the consumer and the enterprise markets. In this announcement, Ericsson explained its new Cloud RAN solution can be integrated into Communications Service Providers’ (CSPs) existing network infrastructure and capitalize on the full interworking between vertically integrated solution and cloud-native architecture. Driven by its Cloud Link solution, Ericsson unveils the new concept named Bluefield deployment, allowing CSPs to leverage their existing network infrastructure, in addition to advanced network functions, such as dynamic spectrum sharing, uplink booster, and carrier aggregation, to deploy the new cloud-native network in a timely manner.

By disaggregating software from hardware and running network functions on Commercial-Off-The-Shelf (COTs) processors, cloud-native network architecture allows CSPs to achieve greater efficient network operation by automating network functions and monitoring performance. The development of open interfaces and reference designs takes one step further toward more flexible and sustainable network deployment. However, Ericsson’s Cloud RAN is still limited to the single radio vendor solution with propitiatory fronthaul interface design due to performance and operational complexity concerns, but the solution does enable an open cloud infrastructure, allowing customers to build a network in any field, any site, any cloud, any server, and any Ericsson radio.

Rapidly increasing data traffic and various connectivity requirements have surged major Tier-One CSPs to deploy 5G networks globally in the fields since 2019, where most of them are still vertically integrated solutions with purpose-built hardware. With the advent of cloud-native network architecture, including in the RAN domain, one key deployment challenge is how to combine new services with CSPs’ legacy networks. To solve the problem, advanced RAN coordination via a gateway server, such as Ericsson’s Cloud Link solution, can be implemented and allow CSPs to extend the cloud solution with the existing purpose-built hardware. However, due to the proprietary nature of interfaces being used in most of the existing 5G networks, such a strategy only works well for a single vendor solution. For those CSPs having cloud-native network deployment demands, but with other vendors’ radio equipment, the transformation to this multi-vendor interoperable cloud-native architecture will not be accessible, therefore limiting the expansion of a flexible and healthy telco ecosystem.

Traditionally, high-performance standards in 5G require purpose-built hardware for baseband, especially for Distributed Unit (DU) and Radio Unit (RU). The cloud-native platform has been built for a central data centre to run virtualized core network functions. Shifting towards Cloud RAN, key stakeholders are still struggling to develop a cost-effective RAN with virtualization before moving to containerized cloud-native architecture, considering most RAN functions require real and/or near-real-time executions. This requires the platform vendors to work intensively with chipset suppliers to develop energy-efficient and highly performed acceleration solutions to address the computing hungry RAN processing needs. For Ericsson's Cloud RAN solution, the company leveraging Intel’s rich portfolio of processors, accelerators, and foundational software creates new opportunities for CSPs to deliver network services with agility and scalability. However, before the solution can get recognized, more successful field trials and commercial deployments are still required to verify its maturity.

According to ABI Research’s market research, the global telecom cloud revenue will grow to US$29.3 billion by 2025, at a 5-year Compound Annual Growth Rate (CAGR) of 27%. In comparison to a Cloud Core network, Cloud RAN can offer new capabilities that allow CSPs to manage their network services to further improve end-user's Quality of Experience (QoE) with granularity. However, as mentioned before, RAN vendors should start focusing on the development of RAN virtualization first, compliant with standards in terms of performance and deployment cost. Apart from that, they also need to closely work with traditional cloud platform suppliers to ensure the applicability of cloud-native architecture in the RAN domain.

Ericsson’s Cloud RAN solution sets a great example for other vendors who pursue the end-to-end cloud-native network architecture and offer CSPs new capabilities to manage their networks. For those customers looking to upgrade Cloud RAN, especially for 5G mid-band network deployment, Ericsson’s solution can offer broad deployment use cases and leverage the selected hardware accelerators to achieve high performance in the combined footprint with reduced time to market. However, the current version of its Cloud RAN can only support its own radio units, which means the solution can only work in the greenfield deployment, or in the brownfield with Ericsson’s radios being deployed. In reality, CSPs are looking for fully opened and multi-vendor interoperable solutions for their future plans. To achieve this goal and unlock a handful of incumbent vendors dominated telecom supply chain, key stakeholders should innovate the advanced processing capability to support massive MIMO alike virtualized RAN performance in a cost-effective manner. Meanwhile, standard bodies also need to speed up the standardization process to lower the threshold for smaller and new vendors to enter the market and simplify the network deployment process. With the advent of open interface and open network solutions for multi-vendor use cases, a competent, highly motivated, and affordable system integrators also play a key role to help CSPs guarantee Quality of Service (QoS), reduce the Total Cost of Ownership (TCO), and create new business models.