The need for high bandwidth is primarily driving the use of Ethernet in cars, Mantsch explained. But another reason is cost. Rather than sticking to the automotive industry's proprietary network technologies such as MOST or FlexRay, which can get costly, Ethernet -- already used in huge volume in consumer electronics products -- could bring down the cost for automotive applications.
So, realistically speaking, how many Ethernet devices are there in cars these days?
Peter Hank, system architect for In-Vehicle Networking at NXP Semiconductors, who recently announced a collaboration with TTTech on an automotive Ethernet switch chip, explained to EE Times that cars in the premium segment are known to use about 20 to 30 Ethernet nodes, roughly half being switches.
Markus Plankensteiner, director of sales and marketing for TTTech's automotive Ethernet development, however, prefers a more conservative estimate. He said, "Up to 10 [Ethernet switches] are currently used in a premium car."
Perhaps more important, NXP's Hank added that many carmakers "will keep the existing networking architecture with LIN, CAN, and FlexRay while they introduce Ethernet for new applications such as Advanced Driver Assistance and camera systems."
Plankensteiner added, "For OEMs that have not yet introduced FlexRay, Ethernet could be a good option as they can leap-frog" others tied to existing in-car technologies proprietary to the automotive industry.
Meanwhile, for the compact car segment, "Ethernet is being introduced in the next few years," said Hank. The minimum number of electrical control units with Ethernet is in the range of two or three, he added. "The Central Gateway will have Ethernet interfaces to the diagnosis connector as well as to major ECUs -- for example, to allow fast software updates during service. The number of Ethernet devices will increase over the next years and replace systems such as existing infotainment solutions based on MOST."
So, where will Ethernet switches be placed?
According to Hank, "Electrical Control Units such as Central Gateway, Head Unit, and Surround View Processing Unit include Ethernet switches and are spread all over the car, mainly inside of the vehicle interior." While each device will be able to communicate with all the others, Hank noted that the target is to keep most communication traffic within such domains as driver assistance and infotainment. Ethernet switches will play a major role in transmitting data, such as camera data, audio, and video streams, inside a vehicle.