Driven by IEEE Standards, Ethernet Hits the Road in 2016
Automotive chip suppliers’ expectations are running high for Tier Ones and car OEMs to start embracing Ethernet switches to connect safety sensors, 360-degree camera systems, infotainment, head units and dashboards. For this scenario to become reality, the Open Alliance led by Broadcom has paved the way by developing BroadR-Reach, a 100Mbit per second Ethernet physical-layer standard specifically designed for automotive connectivity applications BroadR-Reach can run high-bandwidth data over a single-pair unshielded twisted-pair copper wire, cutting cable and connector costs, while reducing the weight of the wiring harness inside a car.
The BroadR-Reach-based automotive Ethernet is already designed into several BMW models and series, as well as Jaguar and Volkswagen’s Passat. However, the number of automakers and car models that has embraced automotive Ethernet remains limited.
Two factors are coming into play to change that landscape in 2016 — the completion of IEEE standards and a roadmap for the future. The completion of IEEE 100BASE-T1 and 1000BASE-T1 standards are both expected next year. Some automotive industry observers view this as critical for the proliferation of automotive Ethernet chips and design wins.
For example, Broadcom licenses today the BroadR-Reach technology to other chip suppliers, including NXP. Micrel and Marvell developed their own family of automotive Ethernet PHYs and switches (with Micrel is now a part of Microchip) but neither is a member of the Open Alliance. With the completion of IEEE 100BASE-T standard, expect more chip vendors to follow the automotive Ethernet trend.
There is some concern that the BroadR-Reach spec and IEEE 100BASE-T standard will be identical. In an interview with EE Times, Timothy Lau, director of automotive at Broadcom, predicted that the upcoming 100BASE-T1 standard will be based on BradR-Reach spec. The industry will not make “different flavors of automotive Ethernet,” he noted. The 100BASE-T standard won’t be the end of the story for automotive Ethernet. Gigabit Ethernet is also coming in 2016.
The emergence of the 1000BASE-T1 standard in mid-2016 provides a roadmap for automotive Ethernet evolution. Marvell in late 2015 became the first to develop Gigabit automotive Ethernet PHY transceiver chip based on 1000BASE-T1 draft standard.
Why gigabit Ethernet in cars?
The automotive industry is known for its conservatism. It’s also notorious for letting automotive-specific, dedicated connectivity technologies to proliferate inside cars.
A vehicle today, for example, consists of such separate domains as Infotainment, Advanced Driver Assistance System (ADAS) and control domains, each using separate pre-defined connectivity technologies including MOST, Flexray, CAN, LIN, LVDS and Ethernet.
Alexander Tan, Marvell’s automotive solutions group product line manager, told EE Times, “The missing link in connecting those different domains is a low-latency, high-speed bus,” said Tan. The single-pair gigabit Ethernet based on the 1000BASE-T1 spec can fill the gap, he said, while making it easy for multiple in-vehicle systems to simultaneously access information. Other obvious places to use 1000BASE-T1 include in connecting multiple cameras, and in a variety of infotainment systems.
The automotive Ethernet — 100BASE T-1 and 1000BASE T-1 included — isn’t like LVDS (Low-Voltage Differential Signaling) which is point-to-point serial connectivity. The automotive Gigabit Ethernet is capable of handling multiple video streams from many cameras.
MOST (Media Oriented Systems Transport) currently dominates as a dedicated high-speed multimedia network technology for car infotainment systems The MOST bus, based on a ring topology, uses synchronous data communication to transport audio, video and voice signals. With Gigabit Ethernet, “We can now support many more streams [than MOST] at a higher data rate in higher resolution,” explained Tan.
The bottom line: Barring an unforeseen technology hitch, the growing imperative to connect cars to the outside world will steadily propel the automotive Ethernet, starting in 2016, as the dominant in-vehicle network backbone.
Junko Yoshida is Chief International Correspondent, EE Times.
Article originally posted on EE Times.