"Opened" or "Closed" RAN in 5G

At the Kálmán Kandó Faculty of Electrical Engineering of the University of Óbuda we have been conducting mobile communication research for many years. In the 4G LTE laboratory of the Institute of Telecommunications, we continuously follow the standardization processes and examine the development trends. Nowadays, the 5G mobile standards became mature, therefore education of the fifth generation mobile network structures and components can be taken into engineering training. However, development trends are not crystal clear. Mobile operators try to make radio access networks (RANs) to be open, but the "openness" term has different meanings for different organizations. Additionally, economic interests can significantly influence the direction of development. Can true openness be achieved? Is it possible to operate "white box" hardware components and open source software in the RAN? Can individual components from different vendors be compatible and interchangeable? In this article, we cannot and do not want to answer all of these questions, but we are trying to provide objective technical analysis that go beyond economic interests. [1]

I. Introduction

Mobile operators decided and moved to the openness of the radio access network for mobile networks. Their main goal was to create independence from suppliers, therefore reduce investment costs. One of the guidelines was the basic elements of a RAN (Radio Access Network) should be "white box" hardware components and the software development should follow the open source method. The creators of 3GPP standards treat these requirements as low-priority, allowing freedom to manufacturers in the protocol elements that implement message exchange between individual network components and other elements. This freedom inevitably resulted manufacturerspecific protocols, which means manufacturer and developer dependency. Manufacturer dependency causes restrictions and limitations in network developments, updates and expansions. These dependencies can be solved only if network components are using open protocols and other standards. Open RAN alliances have been formed to achieve these goals. In addition to network operators, some device manufacturer and developer companies also members of the Open RAN alliances.