Implementing More Effective In-Vehicle Network Infrastructure

For decades automotive networking was dependent on protocols like CAN and LIN. Unprecedented demand for elevated data rates has led to the widespread adoption by automobile manufacturers of Ethernet interconnection technology. This offers orders of magnitude increases in the bandwidth that can be supported. It is not just a matter of raising speeds though. Other aspects now need to be addressed.

Since Ethernet does not offer deterministic operation, the inclusion of additional protocols has been required for it to be applicable in an automotive context. Time sensitive networking (TSN) has meant that safety-critical data can be prioritized, so that it is not detrimentally affected by data traffic congestion. Alongside this, audio video bridging (AVB) has meant that the audio and video streams needed by infotainment systems are all correctly synchronised - thereby ensuring that quality of service (QoS) expectations are maintained.

Another issue is the cable harnessing. This is one of the biggest contributors to the overall weight and cost of a vehicle, and as new capabilities are added to automotive designs, there is the prospect for this to increase still further.

In order to reduce the cable harnessing involved in next generation vehicle models, the domain-oriented networking architectures that have been previously used are set to be gradually replaced by a more operationally efficient zonal approach. This will have centralised high performance computing (HPC) resources connected to a distribution of zone ECUs via multi-Gigabit automotive Ethernet technology. It gets away from everything being related to the function, which meant that cabling was needed to link sensors, imaging devices and actuators with ECUs that could be quite a large distance away (possibly right over the other side of the car). Instead, the new arrangement keeps all of the necessary hardware in close proximity, with responsibility being assigned to the nearest zone ECU.