MADISON, Wis. — The introduction of Ethernet inside the electronic heart of the late-model automobile is inevitable, according to many experts in the automotive chip industry. But when it comes to how Ethernet will be phased into cars and what role it will play, opinions are divided.
Peter Hank, system architect for in-vehicle networking at NXP Semiconductors, is a big believer in automotive Ethernet. He told us recently that carmakers' interest is real. "Many of us are having in-depth discussions with carmakers on Ethernet. Those interested include both US and European car companies."
He does not necessarily agree with Ali Abaye, senior director of product marketing for Broadcom's infrastructure and networking group. Abaye told us last week: "We will start seeing automotive Ethernet replacing CAN in eight to 10 years."
But Hank says that, even though Ethernet will become a car's "system bus" or "backbone" over time, subnetworks below the domain controllers are likely to remain CAN, LIN, FlexRay, and in some cases Ethernet. The point is that the communication network inside a car will be organized hierarchically (see the diagram below), with Ethernet serving as a higher-bandwidth bus allowing different domain controllers to interact with one another.
Ethernet backbone in domain architecture.
"As a system architect, I need to think about communication paths for different domain controllers," Hank said. "For those paths, we know we'll need a much higher bandwidth" than what's available right now.
NXP defines phase 1 of this process as Ethernet being used for reading on-board diagnostics data and updating ECU flash memories. Phase 2 will be driven mostly by camera systems used by advanced driver assistance systems, he said. "OEMs prefer Ethernet" for the camera systems, "because it's a low-risk implementation for them." For example, carmakers can implement cameras with proven Ethernet capability and the 360-degree surround view necessary for parking assistance.
But when car cameras start handling higher-risk jobs like lane departure warnings, reading traffic signals, or spotting pedestrians in the crosswalk, carmakers don't want visual information to be sent as compressed video, according to Hank. For such applications, OEMs are beginning to look to Gigabit Ethernet. "In 2020, there will be cars equipped with Gigabit Ethernet."
Concerns over Ethernet
Phase 2 -- where Ethernet is used inside the car's subnetworks -- will eventually escalate to phase 3, where Ethernet will function as a system bus inside the car. That will be "a paradigm shift for carmakers," but before that happens, Ethernet has to be optimized for automotive applications.