Mobile network architectures: everything you need to know about Open RAN

2023-09-19 20:14:37

Open RAN (open radio access network) technology is an evolution of mobile network architectures that allows operators to use non-proprietary solutions from a variety of vendors and governed by open, interoperable interfaces. Joe Barry, Vice President of Systems & Technology within the Communications & Cloud unit of Analog Devices, explains in detail for ViPress the ins and outs of Open RAN, as well as the state of its deployment, particularly in Europe.

How can we define Open RAN technology?

Joe Barry – Mobile networks are essentially made up of two elements: on the one hand, the “core” which controls the network and processes the data; on the other hand, the radio access network (RAN — Radio Access Network) which connects devices and terminals such as smartphones.

Joe Barry, Vice President of Systems & Technology, Communications & Cloud, Analog Devices

In traditional mobile networks, a single company, also called a “system integrator”, provides the entire network infrastructure (hardware and software), from the antennas mounted on the transmission towers to the technology built into the heart of the network. These “closed” infrastructures are characterized by specific functions and proprietary interfaces.

Open RAN (or O-RAN) networks are different in that they allow several providers to contribute to their operation by creating open interfaces between the different bodies that constitute the RAN network, in particular the radio unit (RU, Radio Unit), the Distributed Unit (DU) and the Centralized Unit (CU). Because protocols and interfaces are standardized, network operators can use equipment and software sold by different vendors. This “openness” makes the system more flexible and promotes innovation.

What are the objectives of Open RAN technology?

Joe Barry – The openness of the network allows operators to choose solutions that match their needs and to acquire, where applicable, hardware and software from different suppliers, but also to add new functionalities and continuously benefit from emerging technologies developed by third parties: in other words, this openness encourages the development of new and original applications and solutions while accelerating innovation.

Standardization of Open RAN interfaces and protocols will also support an increase in the number of providers in the market and make the network more flexible by giving operators the ability to deploy networks with a broader range of functions and services.

What types of networks is this technology intended for? For what applications? Does it concern both public and private networks?

Joe Barry – Designed for 4G, 5G and future generation networks, Open RAN technology applies to high-speed public and private cellular wireless infrastructures. It is important to emphasize that all network elements, except the radio unit (RU), can be virtualized, meaning they can run on a cloud server. Added to network flexibility, this virtualization helps make private 5G networks more attractive, the use cases of which cover many applications, from health to production tools.

What problems does this technology solve for equipment manufacturers and operators?

Joe Barry – Open RAN technology expands the choice of suppliers available to operators, encourages innovation and expands the market available to equipment manufacturers. In addition to radio access networks, it opens up the market as a whole.

Open RAN technology’s standard interfaces remove barriers to market entry, creating innovation space for new entrants who can develop new products with features that improve performance and efficiency. With this interoperability, equipment manufacturers can more easily integrate their products into different networks. Finally, the virtualization of radio access networks and the adoption of software solutions reduce dependence on proprietary equipment, allowing manufacturers to offer solutions that are both more flexible and more scalable.

On the operator side, this opening helps to stimulate the diversity of suppliers, improve the resilience of the supply chain and broaden the choice of products and services, resulting in an expansion of the offering of new products and services. In addition, the use of open and standardized interfaces saves operators from acquiring expensive proprietary solutions, thus encouraging the use of hardware and software available on the market. Operators can also opt for components that meet their specific needs by integrating new technologies or features. The modularity and interoperability of Open RAN technology also makes network upgrades easier: operators can introduce new features without interrupting network operations.

What are the main technological building blocks of an Open RAN network? How does an Open RAN network work? Is the network architecture changed? If yes, how ?

Joe Barry – Open RAN technology works in the same way as a traditional RAN radio access network but has open interfaces between different nodes. With technological evolution, the network architecture has become fragmented: in a classic network, a base band unit (BBU, Base Band Unit) is installed at the foot of a tower and connected to remote radio units ( RRU, Remote Radio Units) or radio units (RU, Radio Units) positioned at the top of the towers near the antennas. The whole constitutes the “base station” or “cell tower”.

© Analog Devices

4G has slightly separated baseband units (BBU) and radio units (RU). But with 5G, the BBU installed at the base of the tower is even more split and now consists of three elements: a distributed unit (DU, Distributed Unit) located near the top of the tower is connected to the radio unit (RU, Radio Unit) and a centralized unit (CU) which can be located several kilometers away. With Open RAN technology, RU, DU and CU units connect through open interfaces. It is also worth mentioning the “intelligent RAN controller”, an important new body that makes the network smarter by running applications at the edge, that is to say as close as possible to where the telephones or connected terminals.

What is a smart RAN controller?

Joe Barry – As its name suggests, the objective of a RAN Intelligent Controller (RIC) is to make a RAN intelligent, that is to say more flexible and more responsive to the evolution of the network and to user needs.

The RIC controller enhances traditional Remote Radio Management (RRM) functions by leveraging data processed by machine learning and artificial intelligence tools. This intelligence allows the network to dynamically allocate and manage radio resources, optimize traffic flow and improve overall performance. Additionally, the RIC can make real-time decisions based on network status, user requirements, and other relevant factors to ensure an efficient and seamless experience.

What does Open RAN technology change in terms of cost, security and cybersecurity?

Joe Barry – Simply put, Open RAN technology will drive innovation and competition among providers, which generally results in lower costs. When it comes to security, open platforms that rely on strong developer communities have been shown to be more secure than closed environments due to the diversity of users who create and test code. L’Alliance O-RAN deals directly with security issues through a working group.

Where are we in the deployment of Open RAN technology?

Joe Barry – It is already being deployed worldwide. While Japan has extensive coverage, Open RAN networks are also deployed in Europe, North America and other parts of Asia.

Where is Europe in terms of advancement and deployment of Open RAN technology?

Joe Barry – Several European operators have launched programs, including 1&1 and Deutsche Telekom in Germany, and Vodafone in the United Kingdom. Until now, these operators have focused on creating infrastructure in areas that were not previously covered. However, the situation could change with new investments in favor of the Open RAN movement.

According to one study recently published by Dell’Orothe global turnover of Open RAN technology is expected to represent more than 15% of RAN technology by 2027, specifying that the European market could exceed 1 billion dollars by the same deadline.

What are the main Open RAN projects carried out in Europe? Is Europe ahead or behind? Is there a risk of dependence on Asian or American equipment manufacturers?

Joe Barry – Although they are in the lead in terms of objectives, European operators are showing relative caution, because we are still at the beginning of 5G which represents a considerable financial challenge for operators. THE recent white paper written by the five main European operators (Deutsche Telekom, Orange, Telecom Italia (TIM), Telefónica and Vodafone) also reflects this sentiment. For example, while emphasizing that Orange is committed to exclusively using products compliant with O-RAN technology during network upgrades from 2025, the document specifies that commitments made under contracts already concluded with suppliers continue to slow the transition to Open RAN technology. When these contracts end, namely from 2025, Europe should be able to catch up quickly.

© Analog Devices

That said, we are seeing progress in Europe. For example, Vodafone launched the first 5G Open RAN site in Bath (UK) early last year, and has since worked with Samsung to promote Open RAN technology across Europe, including Germany and in Spain, both in the form of pilot projects and by deploying virtual RAN networks (vRAN).

Moving forward, we believe that collaboration and adopting a partnership approach will play a key role in driving innovation across the sector.

What are the challenges facing Open RAN technology, whether in technology, deployment or adoption?

Joe Barry – The O-RAN Alliance has made significant progress in defining stable interface standards and creating reference designs for multiple network nodes, including Radio Units (RUs), Distributed Units (DUs), and the RIC Intelligent Controller. The test protocols are also being standardized. Even if these programs will by definition always be evolving as the network is constantly improved, it should be noted that many interfaces are stable. In the radio unit for example, an area where Analog Devices is directly involved, the interface between the small cell and macro cell radio units is very stable. In addition, other suppliers are emerging in this market. When it comes to adoption, generational change in hardware-focused markets is slower than in software-focused segments.

How will Open RAN technology change the mobile network ecosystem, and with which new players?

Joe Barry – The number of suppliers present on the market will increase, as will the product offering. Several newcomers already offer radios, complete network stacks, applications, etc. The O-RAN Alliance has more than 300 contributing companies, a number that has grown significantly over time, from around 40 initially.

Where does Analog Devices stand on Open RAN technology?

Joe Barry – As a pioneer of this technology, a contributing member of the O-RAN Alliance and an active member of other organizations dedicated to Open RAN networks, Analog Devices believes that supplier diversification is healthy for long-term stability, security and innovation of cellular wireless infrastructure.

#Mobile #network #architectures #Open #RAN

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