Communication and bandwidth requirements increase as more and more complex applications appear in the car, for example for enhanced safety and entertainment solutions. End users expect the same level of entertainment functions in the car as known from their home environment. Furthermore, existing vehicle control networks such as the LIN, CAN and FlexRay standards are not designed to cover these increasing demands in terms of bandwidth and scalability that we see with various kinds of Driver Assistance Systems (DAS). Future networking technology should re-use as much as possible from consumer and other non-automotive domains, while taking into account the automotive-specific requirements. This includes hardware components as well as software stacks. Communication solutions for higher bandwidth, such as MOST, are available but expensive for a broader usage in automotive networking systems. Today, in-vehicle networking architecture appears as a heterogeneous system as a result of its historically grown nature (see the left schematic in Figure 1).
Figure 1: Domain architecture, today and in the futureClick on image to enlarge
A new in-vehicle networking system built from scratch and without legacy would most likely have the architecture as shown in the right schematic of Figure 1. Here, ECUs are structured in a hierarchical architecture where application domains are connected through a data highway. Ethernet provides all the prerequisites for such a holistic approach. It could be used as a backbone bus to connect the various application domains as well as for sub-networks that just require higher bandwidth. Today, switched Ethernet networks rely on a point-to-point communication where the available bandwidth is more efficiently used compared to broadcast systems like CAN or FlexRay. The switching concept can be advantageously applied to bridge the domain boundaries without time-consuming packing and re-sorting of the transmitted messages or packages as needed in a complex gateway.
The usage of Ethernet in the car means a paradigm shift in the design of next-generation in-vehicle networking systems: connecting different domain networks, transporting different kinds of data (control data, streaming, etc.) and fulfilling the stringent robustness demands in terms of extended temperature range and EMC performance.