Open RAN has gained a lot of attention during the past few years. The purpose is to transform RAN from a proprietary, fully integrated, and vendor-specific system to a component-like disaggregated system with open interfaces. Motivation forOpen RAN stems from technical, economic, and political reasons, and Open RAN is supported by leading industrial players and regulative bodies. Most importantly, however, Open RAN is driven by mobile operators with an intention to limit dependency on only few RAN vendors, make RAN deployments more flexible, and ensure that operators are fully equipped to reap the benefits of 5G.

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Open RAN divides the network into compliant building blocks

Current globalRAN markets are highly centralised with the three big ones, namely Ericsson, Nokia, and Huawei, controlling over 80 % of the market. Further, currentRAN systems are proprietary and therefore operators are forced to rely on one vendor only in any geographic area. Any possible change of vendors or introduction of a new vendor typically means a large-scale, costly, and one-off network swap. Both hardware and software are vendor specific and purpose-built.In practice, combination of market concentration and proprietary systems leads to strong vendor lock-in. This in turn increases risks of network investments which hampers deployment of new services. Operators want to have more choices and lower risks; they want to have a functional RAN market. Open RAN is a step in that direction.

Technically,Open RAN is expected to deliver open interfaces, decoupled HW and SW, compliance with Commercial Off-The-Shelf (COTS) hardware and cloud-based software. A standard 5G RAN structure eases the task since it divides RAN into key building blocks, namely radio unit (RU), distributed unit (DU) and centralised unit(CU). However, since the current market solution is to have closed interfaces between the units, i.e., CPRI in front haul (RU-DU), and F1 in mid-haul (DU-CU),RAN systems have remained integrated and vendor specific.

Open RAN goes a step further by making the interfaces open. This means that the building blocks delivered by different vendors can co-exist and HW and SW can be decoupled from each other. Further, with relative importance of software increasing, HW does not need to be purpose-built. In contrast, software can be run on general-purpose, or Commercial Off-the-Shelf (COTS), hardware. This can lead to big changes in the RAN ecosystem by lowering entry barriers to new players including e.g., highly specialised RAN software vendors or highly efficient HW vendors.Instead of having only few integrated RAN vendors, operators can have tens of different HW and SW vendors to choose from. This is an appealing change.

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Strong support by leading operators

Open RAN initiatives are led by leading operators in three continents. For example,O-RAN Alliance, formed in 2018, includes big ones, such as AT&T, ChinaMobile, Deutsche Telekom, NTT DOCOMO Orange, Vodafone, BT, Telefónica, and TIM.It also includes newer entrants, such as 1&1 in Germany, Dish in the USA, and Rakuten in Japan. The newer entrants in the list are sometimes referred to as native Open RAN operators since to them Open RAN is a starting point.

Open RAN is anew and evolving area and co-operation coalitions seem to be evolving, too. Asan example, a subset of the big ones in the O-RAN alliance, Deutsche Telekom, Orange, Telefónica, TIM and Vodafone, have signed a Memorandum of Understanding(MoU) to promote development of Open RAN in Europe. Among other activities, they have published Open RAN Technical Priority documents (Release 1 in June2021[i] and Release 2 in March2022[ii]) and a policy paper inNovember 2021[iii].The group is called ‘Open RAN MoU Group’. Other important consortiums aroundOpen RAN include Telecom Infra Project (TIP) and 5G Open RAN Ecosystem (OREC).

Operators withOpen RAN ambitions are too big and important for the big incumbent RAN vendors to ignore. Based on industry news, at least Nokia and Ericsson are showing commitment to Open RAN development; Huawei’s market commentaries seem less enthusiastic.

Practical deployments remain in trial phase, but plans are ambitious

Practical OpenRAN deployments are mostly trial-like or small-scale in nature. Big operators, such as Vodafone, Orange, Telefonica, and Deutsche Telekom, are building competence and forming partnerships with various vendors to advance practical development. For example, Vodafone in the UK switched on its first live 5G OpenRAN site in Bath in January earlier this year. Vodafone’s partners at the first site include Samsung, Wind River, Dell, Intel, Key sight Technologies and Capgemini Engineering.

Vodafone plans to have 2,500 Open RAN sites in Europe by 2027. More importantly, in accordance with its joint ambitions with the UK government, Vodafone plans to use Open RAN in 30 % of its European networks by 2030. Similarly, Orange has stated as an ambition to deploy only Open RAN equipment across Europe from 2025 onwards.Along with the big operator drivers another group of Open RAN supporters is formed by new emerging players. They can proceed with greenfield deployments without burden of legacy technologies. One such example is 1&1 in Germany, a new entrant in the mobile markets since 2019. The company plans to build a fully virtualised 5G network based on Open RAN, partnering with Rakuten.

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Concluding remarks

RAN is the critical link between mobile users and mobile services. With advent of 5G and numerous new use cases it is expected to deliver, operators need more flexibility in RAN deployments. New innovations may be developed outside the current concentrated RAN ecosystem, and operators must find a way to embed the min the networks as they become available. Open RAN with open interfaces and decoupled HW and SW is a promising solution; if it is to deliver its promise, operators may choose different HW and SW components like Lego bricks and build networks that give them the functionalities they need. In sum, operators are likely to get more options in mobile network deployments. While it is a positive change, it also asks for more co-ordination between different vendors, both technically and contractually.

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Our strengths

Omnitele is specialised in mobile network technologies and operational activities within the industry. We have solid project experience on different network solutions and technology generations and are thus well-equipped to address new initiatives within the industry, including Open RAN. We follow the development closely and are prepared to advice our clients in reviewing opportunities and risks involved in Open RAN. We work as an independent advisor with operators, equipment vendors and telecom regulators and policy makers alike.

[i] Open RAN Technical Priority Document

[ii] Open RAN Technical Priority “Release 2”Document

[iii] Building an Open RAN ecosystem for Europe  

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