The ubiquitous CAN bus – a staple of automotive electronics for a long time now – runs at a snail’s pace by today’s standards. Automakers are already using much faster Ethernet for diagnostics and would like to use it for in-vehicle applications, but not with four pairs of wires, which would be required to achieve Gigabit Ethernet networking speeds via 1000BASE-T. Reducing the number of wire pairs – possibly from four to two – would cut the size and weight of Ethernet wiring in a vehicle.
The IEEE recently announced the formation of an 802.3™ Reduced Twisted Pair Gigabit Ethernet PHY study group. “With a tremendous expansion in the number of Ethernet nodes in automobiles forecasted, the efficiencies to be realized in reducing wire pairs to achieve Gigabit Ethernet networking speeds will be of growing importance,” says Steve Carlson, president of High Speed Design, Inc. and chairperson of the study group.
“For everything that automakers want to put in cars between now and 2020, there has to be a high-performance communications backbone, and that backbone is Ethernet,” Carlson says. “Electronic content in cars is going through the roof, and if nothing is done, wiring harnesses could be three times more complex and weigh three times more than they do now.” Carlson and others hope that by 2020 wiring harnesses will weigh about what they weigh today despite all of the anticipated additional functionality.
“It’s possible to do Gigabit Ethernet over fewer than four pairs. What we have to do is look at the different possible solutions and pick the one that is most optimum for performance and cost,” Carlson says.
Persons interested in high bandwidth for future automotive networks are invited to contribute to the study group, which is scheduled to meet at the IEEE 802.3 Ethernet Interim Session, May 14-18, 2012, at the Hilton Minneapolis. For more information visit http://www.ieee802.org/3/RTPGE/index.html.