Today, open radio access networks (O-RANs) have emerged as the buzzword in the global telecom domain. Telecom operators across the globe seem to be warming up to the idea of building O-RANs that are programmable, agile and flexible enough to facilitate innovative use cases. The key advantage of O-RAN technology is that it allows the disaggregation of hardware from software and enables the creation of an open ecosystem that can support multiple vendors. This allows telcos to reduce network deployment costs and offers greater flexibility in deploying networks. Going forward, O-RAN is expected to be the key technology that will help build flexible, robust and programmable 5G networks.

Key features

Unlike the traditional RAN, O-RAN decouples hardware and software, thereby giving operators more flexibility to deploy and upgrade their network architecture. Decoupling hardware and software functions reduces time-to-market, as it is quicker to deploy open networks as compared to traditional ones. Further, open networks can help diversify and reinvigorate the supply chain by promoting competition and innovation. For instance, operators can focus on building and operating a RAN based on mix-and-match components from different vendors.

Other benefits of the technology include the development of future-proof networks so that operators do not have to replace their infrastructure but undertake a simple software upgrade. In addition, O-RAN provides agility and scalability across all network components, allowing operators to deliver higher throughput without any coverage or capacity limitations.

Further, the technology is cost efficient as it reduces operators’ reliance on exclusive vendors and decreases the expenditure incurred on infrastructure. O-RAN standards offer significant cost savings to telcos. For instance, as per an industry report, the total cost of ownership in a greenfield network deployment scenario can be roughly 26 per cent lower for an O-RAN, based on more competitive pricing on radio equipment, maintenance contracts and software.

Network transformation

The deployment of O-RAN technology leads to significant transformation across the telecom network. It not only makes the network more software-driven, but also makes it interoperable among multivendor equipment suppliers, across different generations of networks.

It also ensures that more efficient equipment from different vendors enters the fray and helps telecom companies reduce their costs. O-RAN also allows standardisation of the network infrastructure, making it cheaper and easier for telecom companies to implement network changes. Apart from interoperability and disaggregation of hardware and software, O-RAN promotes self-healing, self-configuration and openness, which help service providers future-proof their investments. It makes deployments cloud-native, easy and affordable to install, maintain and upgrade to any future technology, resulting in a potential reduction in cost by up to 30 per cent.

With this approach, telcos no longer need to add a new layer for a new technology. By enabling a software upgrade, which does not require a site visit, telcos can upgrade the network whenever their subscribers are ready to adopt new technologies. It also makes it extremely easy for service providers to introduce new products and services to their subscribers.

Global adoption scenario

Owing to numerous benefits that O-RAN offers, telcos across the globe have started embracing this technology. Among global operators, greenfield networks that have embraced O-RAN technology include Rakuten, Vodafone, Telefonica and MTN, among others. The biggest example is Japan-based Rakuten, which has deployed more than 5,000 radio stations so far and has already upgraded its network from 4G to 5G, using a collection of at least 18 vendors, providing individual components of the network. Post deployment, Rakuten was able to sign up more than a million subscribers in its first three months. In the US, wireless newcomer Dish will begin the roll-out of the world’s second (after Rakuten) large, greenfield network, based entirely on O-RAN technology. With a commitment to cover 70 per cent of the US population by June 2023, this new network will be a further test of O-RAN’s carrier-grade capabilities and is bound to highlight further development areas.

Recently, Vodafone, NEC Europe and Altiostar jointly conducted the first voice call on an O-RAN on Vodafone’s network in the Netherlands. Going forward, Vodafone and NEC are planning to integrate solutions of O-RAN technology vendors, such as Altiostar and other radio vendors, including NEC’s own 5G radio products. The duo will use commercial off-the-shelf (COTS) hardware from third parties to enable Vodafone to transform its network to a software-based one.

In the Middle East and North Africa, Etisalat became the first operator to successfully launch open virtualised RAN (vRAN). The operator partnered with Altiostar, NEC, Cisco and other leading vRAN technology vendors for the deployment. In Africa, the MTN Group has deployed O-RAN at over 200 commercial rural sites. It has partnered with VANU, Parallel Wireless and NuRAN Wireless for the deployment and its operations in Uganda and Guinea Conakry are already benefiting from this technology. The operator now plans to deploy O-RAN at more than 5,000 sites in rural areas across its 21 areas of operation. In addition, Turkey-based telco Turkcell has joined hands with Mavenir to test and deploy an open vRAN system.

Some other operators have also committed to deployment using O-RAN standards to realise cost savings, future-proof their networks and add flexibility for vendor mixing (widening the supply chain). The trials conducted by these global majors so far indicate that the technology has reached a level of maturity that is ready for commercial deployment.

Indian telcos jump on the O-RAN bandwagon

In India, telcos have started jumping on the O-RAN bandwagon to modernise their networks. A recent report by Bernstein noted that the global pushback on China-based vendors as a provider of 5G networking components might allow O-RAN architecture to gain a stronger foothold in the existing operator networks.

Among Indian telcos, Airtel was the first operator to commercially deploy a vRAN solution, based on disaggregated and open architecture defined by the O-RAN ALLIANCE. It deployed Altiostar’s open vRAN solution across multiple cities in India. Further, Airtel recently hosted India region’s first Plugfest for the O-RAN ALLIANCE. During the event, Airtel partnered with leading players such as Altiostar, Altran, ASOCS, Mavenir, NEC, STL, VIAVI Solutions, VVDN and Xilinx to demonstrate multiple technology use cases including 5G. According to the telco, it is further committed to O-RAN solutions by supporting a number of disruptive and innovative partners, helping them develop solutions capable of addressing the scale and complexity of its network and that of other brownfield operators around the world.

Recently, Airtel and Qualcomm Technologies announced their collaboration for accelerating deployment of O-RAN-based 5G networks in India. Through Airtel’s network vendors and device partners, Airtel will utilise Qualcomm 5G RAN platforms to roll out virtualised and O-RAN-based 5G networks. The operator stated that it is committed to driving the success of O-RAN and is working with Qualcomm Technologies to explore and implement the O-RAN approach for India. Further, Airtel and Qualcomm highlighted that the flexible and scalable architecture of O-RAN will create new opportunities for small- and medium-sized businesses to become viable players in the deployment of 5G networks.

Reliance Jio has been quite vocal about its plans to accelerate deployment of an O-RAN-centric disaggregated RAN solution. In 2018, Reliance Industries acquired the US-based Radisys, which has a presence in Bengaluru. The start-up, which had built expertise in open systems and virtualisation, is now reportedly working on Jio’s O-RAN software stack. In 2019, Reliance Jio teamed up with a group of international telecom service providers, vendors and integrators for the Open Test and Integration Centre initiative to facilitate testing and integration of O-RAN architecture and interfaces. In fact, a recent industry report by Bernstein stated that Reliance Jio’s plans to build its own 5G software stack and embrace O-RAN techniques will help the telco save money that it gives to existing 4G network suppliers as premium payouts.

Further, Vodafone Idea Limited has been leveraging Mavenir’s O-RAN solutions for 4G to scale up adoption. Vodafone Idea has also been engaged with partners within the O-RAN space for developing a robust solution to cater to traffic requirements on its network.

Testing and measurement for O-RAN

The creation of seamless and flexible interoperability in a multivendor, open ecosystem introduces new test, management and integration challenges that require diligence and cooperation to overcome. Key challenges that operators need to address while considering O-RAN are interoperability, ownership accountability, troubleshooting and isolation of problems, and managing and orchestrating all multivendor virtual network functions and physical network functions on a common cloud infrastructure, which may also be multivendor.

Further, the number of test cases operators and network equipment manufacturers need to go through and the amount of testing required is much greater with O-RAN as compared to traditional RAN. This is because of a larger combination of vendors under the O-RAN system, which dramatically increases the cycle time for testing every software release, every regression and implementing testing automation.

To address these challenges, an open test and integration centre (OTIC) has been established in Berlin, Germany, as a collaborative hub for commercial O-RAN development and interoperability testing. The operator-led OTIC initiative benefits from the support of global telecom organisations with a shared commitment to verification, integration, testing and validation of disaggregated RAN components.

The OTIC lab provides a structured environment with common test platforms and practices that enable software developers, equipment manufacturers and system integrators to verify functional compliance to O-RAN ALLIANCE specifications. The lab enables interoperability of disaggregated 5G access infrastructure elements to be fully validated prior to network deployment. However, operators must take responsibility for multivendor, disaggregated elements and make sure they undertake collaborative efforts to maintain quality of experience standards for O-RAN. Further, telcos would need to integrate robust multivendor testing processes from the lab to the field, and beyond, to fully realise and reap open network architecture benefits.

Opportunities and outlook

The concept of building open networks seems to be gaining traction among global as well as Indian telecom operators. The year 2021 will be critical in the O-RAN space as laboratory experiments and field trials for O-RAN are expected to give way to commercial deployments. With full-scale greenfield O-RAN network deployments under way in Japan and the US, along with smaller-scale deployments being planned in Europe, the deployment of O-RAN technology in telecom networks is set to expand rapidly.

As per industry experts, the number of O-RAN-based radio units (RUs) deployed by operators and private networks will grow to more than 800,000 in 2025 from only 122,000 RUs in 2020. In the coming years, O-RAN is expected to save money in multiple market segments, including both high capacity applications and coverage-limited applications. When this happens, telcos would look to apply the O-RAN business model to both rural as well as urban areas in many mainstream markets. However, this open network expansion would depend on the continued growth of a healthy ecosystem that would require adding new suppliers and innovations to this developing market.