Ethernet tackles automotive EMI challenge

January 09, 2013 // By Mike Jones, Micrel
Ethernet has already been widely accepted by the automotive industry as the preferred interface for on-board-diagnostics (OBD) and has been deployed in various car models. It provides increased bandwidth over traditional automotive buses, resulting in a reduction in software download times from hours to minutes compared to traditional methods. This adoption will be accelerated with the introduction of a standardized IP Diagnostics interface, as specified in ISO 13400, using Ethernet as the physical layer.

The expansion of Ethernet-based networks in the automotive industry has continued with next-generation infotainment and driver assistance systems. Originally found in only luxury high-end vehicles, such applications are fast becoming differentiating features on mid-range and even basic models. These new applications have, in tandem, generated demand for greater system bandwidth, which continues to rapidly rise, as shown in the timeline below:

• 1981: CAN @1000 Kbps

• 2005: FlexRay @ 10 Mbps

• 2001: MOST @ 50 Mbps

• 2008: Ethernet @100 Mbps

• Ethernet @ 1000 Mbps (RTPGE IEEE802.3bp)

Advanced Driver Assistance Systems (ADAS) constitutes one of the fastest growing applications within the automotive market. Driven by government legislation and a desire for enhanced in-vehicle safety camera sensor networks are becoming commonplace. By 2017, camera-based module sales are expected to increase to 34 million in total, from 6.1 million in 2010 (IMS Research). This is in part due to the National Highway Traffic Safety Administration (NHTSA) ruling requiring every car sold in the United States from 2014 be fitted with at least a single rear view camera or sensor.

System costs are significantly lowered using Ethernet connectivity for multi-camera sensor networks in the car. Traditional proprietary methods are making way for open standard Ethernet. This has been reflected in the ISO 17215 Video Communication Interface for Cameras (VCIC) specification, defining Ethernet connectivity for use in vehicle camera and/or sensor applications.

Ethernet is emerging as the preferred network of choice for this new generation of networked vehicles, continuing to be the de facto networking bus for all other markets, thanks to an offering of ample bandwidth and open standardization. True standardization results in multiple interoperable supplier solutions, rapidly driving down costs.

This is in contrast to current popular infotainment networking technologies, for example MOST. The proprietary nature of MOST has often been blamed for failing to deliver the cost needs of car makers, as reported in the Hansen report, November

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