Puneet Sethi, Senior Vice-President and General Manager, RAN Business Unit, Mavenir

The telecommunications industry is changing rapidly and an open virtualised radio access network (open vRAN) is the future of network technol­ogy. It offers flexibility and a variety of options, which are its key strengths.

So, what is Open vRAN? Open vRAN is a disaggregated RAN functionality built using open interface specifications between elements. It can be implemented in vendor-neutral hardware and software-defined te­­ch­nology based on open interfaces and co­mmunity-based standards.

The architecture adapts to the assets and the requirements of the carrier as opposed to providing a black box solution, where the carrier must adapt. This is one of the leading value propositions of Open  vRAN. The architectural choices will de­pend on the kind of spectrum owned by communication service providers (CSPs), or whether they want to leverage cloud infrastructure, and if so, what type (public, private, hybrid), and what type of transport they have at each site. With Open vRAN, the architecture can vary with each operator and even vary at each si­te of the same op­erator. Operators can make different ch­oices based on each site. Multiple architectures can coexist within a single network. With the right architecture choices, Open vRAN allows the delivery of key perform­a­nce indicators (KPIs) that match or exceed the existing black box solutions.

One of the greatest flexibilities that Open vRAN offers is the ability to use commercial-off-the-shelf (COTS) hardware and open interfaces. This means that the evolution of the network is not locked into past choices. Open interfa­ces en­ab­le the selection of radio unit (RU), or centralised unit (CU)/distributed unit (DU) products, based on which product is best in class and not because they rely on proprietary interfaces or come from the same ve­ndor. Open vRAN gives the ch­oice and flexibility to de­sign the network based on individual CSP requirements. In contrast, in legacy solutions, the black box solution is fixed and adjustments are required to deploy, manage and evolve the network.

The mobile network industry is evolving and growing continuously. The industry is now several years into the development and deployment of vRANs. With Open vRAN, the evolution of RAN is taking place. With live networks in operation and ongoing trials, Open vRAN technol­ogy has been shown to work effectively on a commercial scale worldwide. The industry is also getting closer to being competitive with traditional RAN systems. A key development under way is the move to “cloud-native” RAN, where baseband so­ft­ware is deployed in containers and

ma­­­na­­ged using cloud orchestration tools. At the same time, through the O-RAN Alli­­ance, operators are collaborating with the wider ecosystem to create open interfaces between RU, DU, CU, RAN intelligent controllers (RICs), and the O-Cloud infrastructure layer (i.e., the O-RAN cloudification and orchestration platform) to specify an open RAN architecture.

Today, in addition to 4G and 5G products, there are multi-G solutions to meet the 2G and 3G requirements. In the fu­t­u­re, we expect to see more radio access te­chnologies that support the evolution from 5G to 6G, as well as more options in the Open vRAN product ecosystem. The fu­tu­re may also bring in more products such as virtualised cell-site routers. Ima­gine a cell site router that exists as a separate box and could potentially run on the same COTS server as the DU, especially at the cell site.

The use of public, private and hy­br­id clouds is gaining traction. CSPs may sta­rt se­eing deployment of bo­th  CU and DU in the public or hybrid cloud as well as private networks and new services. We are also entering the new phase of DU optimisation. The availability of new silicon solutions that support the DU and transport fu­nctionality enables a lower cost of the DU, which is essential for the Open RAN eco­system and for reducing power consumption.

Open vRAN should further evolve using advanced technologies such as artificial intelligence (AI) and machine learning (ML), with different optimisations and use cases. For example, AI/ML can be incorporated into RICs, schedulers and beamforming. In addition, we expect to see the evolution of Open vRAN to non-terrest­rial networks, with a global network based on satellites built around 5G Open vRAN architectures.

Open vRAN is also at the centre of the launch of 5G networks, given its ability to support a plethora of 5G use cases. It is gaining popularity as 5G roll-outs are picking up pace and operators are looking forward to lowering their capex and opex amidst rising capital intensity and subdued subscriber and revenue growth. Open vRAN solutions will also allow mobile network operators to design new and high-value services. It will enhance customer experience and foster a more connected relationship with consumers as more personalised services emerge with 5G.

Going forward, we will see microservices-based vDU architectures, and more advanced 3GPP use cases as the standards evolve.