The advent of the 5G era has put the spotlight on building open radio access networks (RAN) that are programmable, agile and flexible enough to facilitate innovative use cases. Unlike the traditional RAN, open RAN decouples hardware and software, giving operators more flexibility to deploy and upgrade their network architecture. Decoupling the hardware and software functions reduces the time-to-market since it is quicker to deploy open networks vis-à-vis traditional ones. Further, the technology is cost efficient as it reduces operators’ reliance on exclusive vendors and decreases the expenditure incurred on infrastructure. Owing to these benefits, operators across the globe have started working towards building open networks. Going forward, the 5G world is expected to witness extensive deployment of virtualised and automated networks based on the concept of open RAN.

Role of open RAN in 5G

A key factor driving the adoption of open RAN is its role in facilitating 5G networks. According to industry reports, 5G deployment costs are expected to fall by 30 per cent between 2019 and 2022, if a network is built in the traditional way, and by 50 per cent if it is based on open architecture. Further, open RAN enables operators to increase the number of their network infrastructure partners, and deliver better and more cost-effective 5G networks. By adopting open infrastructure, which comprises open source software, non-proprietary hardware and multivendor collaboration, telecom operators can create a fully virtualised infrastructure capable of delivering critical 5G-based services. Open RAN can thus help operators to reduce deployment costs, improve interoperability between vendors, and bring intelligent computing to the edge of the network, thereby improving performance and unlocking new 5G capabilities.

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. Moreover, these are futureproof networks that do not need replacement of infrastructure but only a simple software upgrade. They also provide agility and scalability across all network components, allowing operators to deliver higher throughput without any coverage or capacity limitations. In addition, network capacity augmentation and optimisation is enhanced by the simplification of nodes and the usage of new automated methods and artificial intelligence (AI) algorithms.

Global activity in the open RAN space

Since telecom stakeholders have recognised the key benefits that open networks bring to the table, the global open RAN space has been beaming with activity. The operator community, vendors as well as other stakeholders are actively engaged in forming collaborative alliances to help drive uptake. One of these alliances, the OpenRAN Project Group focuses on developing a vendor-neutral hardware and software-defined technology based on open interfaces and community-developed standards. Another such group is the O-RAN ALLIANCE, which was founded by telecom operators to clearly define requirements and help build a supply chain ecosystem to realise the twin objectives of openness and intelligence. Members of the O-RAN ALLIANCE include AT&T, Deutsche Telekom, Intel, Verizon and SK Telecom. In fact, in 2018, India’s Reliance Jio and Bharti Airtel also joined the O-RAN ALLIANCE. Apart from this, there is the Open virtual RAN (vRAN) initiative, which is backed by Cisco and was formed with a vision to accelerate the viability and adoption of open vRAN solutions and ensure their extension to the broader network architecture. Recently, a group of over 30 companies formed the Open RAN Policy Coalition to push governments to take measures for increasing the development and adoption of open RAN technology.

Further, telcos across the globe have started scaling up the adoption of open RAN. In October 2019, Rakuten successfully implemented the world’s first virtualised and distributed open RAN in Japan. Another Japan-based operator, NTT DOCOMO recently launched pre-commercial 5G trials using open RAN fronthaul interfaces on a part of its network. The UK-based Vodafone Group was among the first operators to announce trials for the deployment of open RAN in over 100 rural locations in the UK in October 2019. The operator has conducted extensive field trials in the UK with Mavenir and in Ireland with Parallel Wireless. Recently, Vodafone, NEC Europe and Altiostar jointly conducted the first voice call on an open RAN on Vodafone’s network in the Netherlands.

In Europe, Telefonica recently announced its plans for conducting open RAN trials in Brazil, Germany, Spain and the UK. Ahead of these trials, the operator had entered into partnerships with Altiostar, Gigatera Communications, Intel, Supermicro and Xilinx, Inc. to foster the development of open RAN technologies in 4G and 5G. In the Middle East and North Africa, Etisalat became the first operator to successfully launch open vRAN. The operator partnered with Altiostar, NEC, Cisco and other leading vRAN technology vendors for the deployment. In Africa, the MTN Group has deployed open RAN at over 200 commercial rural sites.

Opportunities for Indian telcos

In India too, telcos have started jumping on the open RAN bandwagon to modernise their networks. A recent report by Bernstein noted that the global push-back on China’s Huawei as a provider of 5G networking components might allow open RAN architecture to gain a stronger foothold in the existing operator networks.

In fact, Airtel was the first operator in India to commercially deploy a vRAN solution based on disaggregated and open architecture defined by the O-RAN ALLIANCE. To this end, 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 open 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.

Reliance Jio too has been quite vocal about its plans to accelerate deployment of an open RAN-centric disaggregated RAN solution where AI, cloud infrastructure, blockchain and augmented/virtual reality  form the essential building blocks for new-generation programmable digital infrastructure. 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 open 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 open 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 open RAN techniques will help the telco save the money that it gives to existing 4G network suppliers as premium payouts.

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

The way forward

Net, net, the concept of building open networks seems to be gaining traction among global as well as Indian telecom operators. However, even as open RAN deployments pick up pace, issues such as ensuring interoperability of networks and the possibility of telcos interchanging vendors’ software and hardware while being able to achieve the same performance remain unresolved. These issues are expected to be resolved as more and more operators transition from the trial phase to the commercial deployment phase. Further, telcos would need to integrate robust multivendor testing processes from the lab to the field and beyond to fully realise and reap the benefits of open network architecture.