Flexible Multi-Operator RAN Sharing: Experimentation and Validation Using Open Source 4G/5G Prototype

In this paper, we present an open source Radio Access Network (RAN) sharing prototype, based on Open Air Interface (OAI) platform, which employs slicing features provided by an open source RAN controller, known as FlexRAN. Accordingly, this paper analyzes the benefits of employing network slicing in the RAN to introduce more flexibility in the configuration of RAN sharing architectures. The contribution of this paper is twofold. Firstly, we propose a flexible RAN sharing architecture where a specific radio slice is allocated to each operator that shares the same RAN, while considering specific Service Level Agreement (SLA) constraints. Secondly, we validate the proposed architecture via a simple radio resource allocation algorithm, which enables dynamic creation and configuration of radio slices, making it possible to transform on-the-fly a "Multi-Operator Core Network" (MOCN) sharing scenario, wherein the spectrum is shared by multiple operators, into a "Multi-Operator RAN" (MORAN) scenario, wherein the spectrum is isolated among the operators that share the same RAN. Emulation results show that the employment of the proposed algorithm enables a more flexible allocation of the radio resources among the sharing operators, providing better performance in terms of end-to-end latency and throughput compared to a static RAN sharing approach.