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.