Efficient Hybrid UDP Multicast and Unicast Algorithm for ECU Firmware Updates
Kyung Dong Kwon, Seong Hyeon Lim, Young Soo Do, Sung Bhin Oh, Sung Keun Cha, Beom Gi Suh, Young Min Kim, Jae Wook Jeon · 2025
Efficient and scalable firmware updates are essential in modern vehicles as the number of Electronic Control Units (ECUs) continues to grow. This paper presents and evaluates three OTA update strategies—unicast, hybrid multicast-unicast, and delta-based hierarchical—using real firmware binaries and a chunk-level simulation framework. By segmenting each firmware into 512-byte chunks and analyzing chunk-level similarity across eight versions, multicast opportunities and clustering potential are identified. Simulation results show that while unicast requires 5,778 transmissions, the hybrid strategy reduces this to 1,927, and the hierarchical delta-based method minimizes it to just 2. These findings highlight the effectiveness of firmware clustering and delta optimization for OTA deployment in zonal automotive architectures.