As automated and connected cars roll into dealerships over the next decade, they’ll need high-bandwidth networks to support these critical, data-hungry functions. Korean automaker Hyundai says it is committing to faster ethernet connectivity to power the core of its next-gen vehicles.
The Korean automaker has announced that it will “accelerate innovation, provide ‘over the air updates,’ and shorten the life cycle in bringing new capabilities to market” by using ethernet at up to 1 gigabit per second (Gbps). A collaboration with Cisco will see primarily ethernet-driven Hyundais hit the market starting in 2019.
Electronics in modern cars have become incredibly complex, but they’re slower—like, 10,000 times slower in data throughput—than a USB 3.1 port. Most cars connect their electronic control units (ECUs) via a controller area network, or CAN. Bosch introduced this standard in 1986 to reduce the weight and cost of heavy wiring harnesses, and it has proven to be a robust, reliable, and inexpensive network for in-car use. While initially meant for automobiles, CAN has moved into the marine, aerospace, and medical industries, where some hospital operating rooms rely on it. But CAN can’t manage adaptive suspensions and other drive-by-wire systems with precision. It also can’t process sensor data from radar, lidar, and visual cameras fast enough. For fully autonomous cars—or even for one pedestrian-detection alert—CAN just isn’t the answer.
As a serial interface, a CAN bus can only transmit or receive one bit of data at a time; compare this to the multiple packets of bits sent and received by your mobile phone. Speeds can top 1 megabit per second, which is essentially the gap between a 3G and 4G cellular network. CAN simply can’t keep up with sensors spewing out data greater than 100 times a second. Ethernet, by contrast, has a maximum data output that’s 1000 times faster than the fastest CAN interface.
But gigabit ethernet, despite how cheaply it can be embedded on computer motherboards, is expensive in a car. So far, it has been limited to infotainment systems like Jaguar Land Rover’s InControl Touch Pro and other similar uses; other leading in-car networks, such as FlexRay, have speeds of 10 megabits per second and can handle functions such as adaptive cruise control. Yet the fact remains that it’s neither simple nor cheap to make cars run as fast as our USB ports. Network security, electrical interference, cable length, and syncing dozens upon dozens of ECUs are things that keep automakers’ software developers and electrical engineers up all night.
Hyundai isn’t looking to replace CAN, nor is it suggesting the industry should. Many simple controls, such as for brake lights or window switches, will still be wired with CAN for many years to come. Until the R&D costs of ethernet (or another faster technology) come down, most cars will use a combination of CAN, FlexRay, and ethernet.