The first Ethernet applications for the automotive industry are On-Board Diagnostics (OBD) and the update of ECU flash memories. For the reading-out of diagnostics data and the updating of software within a given time frame, the performance of existing in-vehicle bus systems such as CAN and FlexRay was not sufficient. Ethernet 100Base-TX with CAT 5 has been chosen for the interface between the vehicle and the diagnostics test equipment. The higher bandwidth of Ethernet saves costs in service and production. ISO 13400 and ISO 14229 utilize existing industry standards and define a long-term stable state-of-the-art diagnostics standard. Products and components are already available from versatile suppliers as automotive requirements such as robustness and temperature tolerances have been relaxed for this specific use case.
2.2 Generation 2: Driver assistance systems and infotainment
The second generation of Automotive Ethernet will address infotainment and camera systems for surround view applications. Today’s rear-view camera solutions often use LVDS for the transfer of video data, which works well for single cameras. In future systems, this will consist of more cameras and fuse with sensor data from short/long-range radar, for example (Figure 3). An LVDS-based system becomes inefficient in terms of wiring harness and expensive cables and connectors. Switched Ethernet allows video cameras to be connected to a central control unit for synchronization and further processing.
Ethernet cameras can further benefit from “Energy-Efficient Ethernet” (IEEE 802.3az), which introduces a Low- Power Idle (LPI) mode and wake-up functionality to save energy when the cameras are not being used. Additionally, solutions for Power over Ethernet (PoE) are preferred to further reduce wiring harness. The demand for higher bandwidth and lower latency is obvious. Multiple high-resolution cameras for uses such as object detection require uncompressed data transfers, for example to avoid compression artefacts for obstacle detection, and are a strong driver of higher bandwidth.
Figure 3: Camera and radar for Driver Assistance Systems
Recent infotainment solutions are mainly based on proprietary and non-scalable technologies. Automotive Ethernet addresses this emerging application field in a cost-effective manner by making use of the AVB standard. Synchronized transmission of video and audio data with guaranteed latency can already be achieved with existing AVB Gen 1 Ethernet components. However, both applications fields will benefit from current AVnu standardization activities and the most recent Switch and PHY developments based on the BroadR-Reach physical layer.