An Open-Source 5G Sidelink for Reliable Device-to-Device Communication

This paper presents the design, implementation, and evaluation of open-source 5G NR Sidelink (SL) protocols for reliable device-to-device (D2D) communication, which were contributed to the OpenAirInterface (OAI) repository. The 5G SL capabilities are enhanced in the OAI software by integrating key physical (PHY) and medium access control (MAC) layer features, including the Physical Sidelink Feedback Channel (PSFCH) support, Hybrid Automatic Repeat Request (HARQ) processes, Channel State Information Reference Signal (CSI-RS) measurements, and CSI reporting mechanisms. Dynamic resource allocation is also integrated, supporting autonomous SL resource scheduling without the need for gNB coordination. The new features were tested using an open-source radio frequency simulator (RFSim), and an over-the-air (OTA) Software Defined Radio (SDR) testbed. We conducted comprehensive performance evaluations and validation experiments to demonstrate the reliability and practical viability of the system under diverse conditions.