Incremental Over-the-Air Update for Software-Defined Vehicles with C-V2X

Software-defined vehicles (SDVs) rely on intricate software systems distributed across multiple electronic control units (ECUs), making errors inevitable and costly to address via conventional recalls. Software over-the-air (OTA) update offers a real-time, cost-efficient solution while enabling software customization. This paper presents a comprehensive OTA framework for SDVs, utilizing a robotic vehicle and an industry-grade roadside unit (RSU). The framework leverages Docker to create isolated environments and Docker Compose to manage rolling updates, minimizing disruptions and enabling rollbacks. We also propose RSU- and vehicle-side mechanisms for incremental update and evaluate the performance of Cellular Vehicle-to-Everything (C-V2X), including V2X and 5G, alongside Wi-Fi for OTA transmission. Our study of model weight (ResNet) and software package (YOLO, UFAST) updates shows that C-V2X achieves over $30 \times$ faster transmission than Wi-Fi. Using 5G within C-V2X further reduces transmission by up to $2339 \times$ compared to V2X, establishing it as a highly effective OTA solution. Incremental updates enhance efficiency by cutting delays by $2 \times$ versus full updates, with a 32 KB chunk size yielding the highest success rate and shortest times across distances. Incremental update also reduces transmission by up to $5000 \times$ using C-V2X, enabling package downloads even while the SDV is in motion.