The Impact of Different Compatibility Schemes on the Static Bus Load in Vehicle Networks

The automotive industry is currently facing significant transformations with the shift toward electric vehicles, automated driving, and the increasing connectivity (between vehicles and smartphones, the Internet, and infrastructure like traffic lights). This results in an increase in complexity of the electric/electronic (E/E) architecture, measurable, for example, by the number of signals (i.e., pieces of information transmitted) in in-vehicle networks, which show an exponential growth. Improvements to the development processes, to tackle the resulting challenges, are part of active research. One of the recently proposed concepts is the introduction of backward compatible interfaces between the electronic control units (ECUs). Backward compatibility is achieved, by transmitting both new and old versions of the signals of an ECU, which results in increased bandwidth usage. To assess the applicability of this concept, for the cost-sensitive automotive industry, we analyzed the increase in bandwidth consumption in detail. By using historic data of a real-world vehicle network development process, we simulated development processes following two different backward compatibility schemes and calculated the bandwidth consumption caused by each of them. Our results show that the concepts are applicable within some limits, and that a hierarchical backward compatibility scheme induces a smaller increase than a simple backward compatibility scheme.