Enhancing In-Vehicle Networks with CAN-FD: A study of Protocol Improvements over Classical CAN

Classical Controller Area Network (CAN) technology has been widely used in in-vehicle networks for decades. However, with the increasing complexity of modern vehicles, CAN's limitations in terms of data rates and packet sizes have become constraints. To overcome these limitations, CAN with Flexible Data Rate (CAN-FD) has been introduced as an enhanced protocol that is compatible with existing CAN networks. This paper provides a comparative study between classical CAN and CAN-FD protocols. The key differences include CAN-FD's ability to transmit larger payloads up to 64 bytes per packet and achieve higher bit rates up to 10 Mbps. Major protocol improvements include the flexible data rate for the data field in CAN-FD frames, bandwidth allocation for larger data segments, and a higher maximum baud rate for faster arbitration. These enhancements significantly improve the usable data throughput and latency compared to classical CAN. New capabilities enabled by CAN-FD include transmitting larger messages and software files for advanced automotive applications and reprogramming. Overall, CAN-FD provides substantial performance gains while maintaining compatibility with existing CAN networks, making it an attractive upgrade path for enhancing modern in-vehicle networks.