Design and Implementation of Softwarized Radio Access Network System Using ETSI-Standard Software Reconfiguration Framework

Abstract

This dissertation presents a method of applying a software reconfiguration framework which was developed by European Telecommunications Standards Institute (ETSI) technical committee Reconfigurable Radio System (RRS) in radio access network (RAN) system. The ETSI RRS software framework enables network operator to achieve platform-independent software reconfiguration. The RAN system under consideration in this dissertation applies software-defined RAN (SDRAN) and cloud RAN (C-RAN), which are representative software-based RAN technologies. Furthermore, it is assumed that the hardware platform for the RAN system is composed of heterogeneous hardware platforms. Since hardware platforms are provided from different vendors, the software interface for managing each platform is also platform-dependent, and radio applications developed by 3rd parties are not guaranteed to be portable. In particular, as the data plane of RAN system requires a lot of computation compared to the control plane, it is common to perform data plane processing with a heterogeneous hardware platform. Consequently, this dissertation aims to solve software portability issues and manage platform-independently radio applications in data plane of RAN system. In this dissertation, to solve the above-mentioned issues, the ETSI RRS software reconfiguration framework, which was applicable only to the mobile device, was redesigned and applied to the RAN system. First, to resolve the software portability issue, the proposed framework employs a specific (radio) virtual machine as well as a radio library; the heterogeneous hardware platforms are abstracted, enabling the joint optimization of the radio application code and hardware platform. Second, to achieve platform-independent software management, the proposed data plane framework adopts a double-layered structure enabling users to exploit high-level software management for the SDRAN data plane The feasibility of the proposed framework is verified through a proof-of-concept (PoC) system with the proposed double-layered structure. Based on this PoC system, we show that users can efficiently perform software management. According to the numerical results obtained from the PoC system, the proposed double-layered structure introduces negligible additional footprint in terms of computational resources, memory requirements, and latency.