In-Car Ethernet Speeds Up Autonomy Support
Autonomous vehicle developers talk a lot about things like lasers and artificial intelligence, but some underlying technologies are just as important.
One of these, automotive Ethernet, may lack sizzle but is set to gain a lot of speed. In March, the engineering group behind the technology said it would have a standard for multi-gigabit in-car networks by 2020.
Level 4 AVs, designed to drive totally on their own in certain areas, will need faster internal networks, ABI Research analyst James Hodgson told The Connected Car.
“In-vehicle communications is one of the most overlooked technologies to support autonomous driving,” Hodgson said.
Bringing these cars into mass production may be what drives a cautious auto industry to more fully embrace the network protocol that enterprises have been built on for decades. Up until now, automotive Ethernet has been gaining acceptance, but mostly for diagnostic and infotainment uses.
To get all the sensors and components in a vehicle to communicate, automakers until now have mostly used networks designed specifically for cars. The main system, the Controller Area Network Bus, or CAN Bus, is used in most cars today to link multiple engine control units, or ECUs. But some cars have other networks for specific systems, such as infotainment.
Scale, speed and standardization are what make Ethernet an attractive technology for use in cars. While the major in-car networks may ship in the tens of millions each year, Ethernet gear rolls out in even greater volumes, so economies of scale can make it less expensive, Hodgson said. The overall workforce of engineers who understand Ethernet is also bigger, and the Institute of Electrical and Electronics Engineers (IEEE) has a long track record of producing faster versions of Ethernet, from 10 Mbit/s (megabits per second) in the 1980s to 400 Gbit/s (gigabits per second) last year.
Automotive Ethernet emerged around 2011, spearheaded by networking chip maker Broadcom. It developed a system called BroadR-Reach that allowed Ethernet to go over thinner cables — crucial for reducing space and weight, which are important factors in cars. Broadcom helped turn automotive Ethernet into a standard, so makers of different components could be sure their products would work with those from other vendors, said Ali Abaye, Broadcom’s senior director of marketing for automotive Ethernet. The specification got a speed boost to 1 Gbit/s in 2016 and is now headed for up to 10 Gbit/s. According to the IEEE’s timeline, the multi-gigabit standard should be completed by September 2020.
That would be good timing for the broad introduction of self-driving cars, Hodgson says. For example, BMW plans to ship vehicles in 2021 that are capable of Level 4 or Level 5 autonomy. It was an early adopter of Ethernet.
Automotive Ethernet does have one rival for multi-gigabit performance, Hodgson said. HDBaseT, or IEEE 1911, has an automotive version with speeds up to 6 Gbit/s. Mercedes-Benz parent company Daimler has said it will use HDBase-T in some vehicles.
Cars with Level 4 and 5 automation will need faster networks to feed powerful, central onboard computers, Hodgson said. Those computers will take in high-definition data streams from onboard sensors, map data from the cloud, and information from nearby infrastructure such as smart signs. They will use that to make split-second driving decisions, which the car needs to carry out instantly. Lower levels of automation, such as current advanced driver assistance systems, allow for some processing of data at the edge, but more advanced systems will need full data streams from around the car, Hodgson said.
A video stream from a 4K camera in the front of a car would require 6 Gbit/s to 8 Gbit/s of bandwidth, Broadcom’s Abaye says.
Self-driving equipment makers are already getting started with Ethernet. The Nvidia Drive Pegasus, an onboard AI computer scheduled to be available to car companies later this year, will include an automotive Ethernet switch from Marvell with 1 Gbit/s capability.
