Broadcom Tackles 5 Questions on Ethernet in Cars
Frequently asked questions about automotive Ethernet include its specific applications inside a car and whether it has enough bandwidth to meet ADAS requirements. There’s also concern about Broadcom’s intellectual property, and most important, which car OEMs — other than BMW — are already using Ethernet. We sat down with Timothy Lau, director of automotive at Broadcom.
EE Times: Besides BMW, who else in the auto industry is on board with the use of Ethernet in their cars?
Timothy Lau: Based on our direct engagement with automotive OEMs and Tier One’s, we see multiple OEMs developing Ethernet network solutions based on BroadR-Reach technology. Beyond the 2014 and 2015 BMW X5, those that are public now include the 2015 Jaguar Land Rover XJ and the 2015 Volkswagen Passat.
EE Times: For what specific applications are they using Ethernet in their models?
Lau: BMW has begun using automotive Ethernet to connect cameras to the optional surround-view system electronic control unit in the BMW X5. The Jaguar Land Rover is using automotive Ethernet in its infotainment network. The Volkswagen Passat is using Ethernet for a parking assistant. The Passat is a good example that illustrates BroadR-Reach is now rapidly moving into mass-market cars.
EE Times: What’s prompting a car maker to use BroadR-Reach for parking assist?
Lau: For parking assist, cost is the driving force. For example, car makers are adding several surround-view cameras in addition to a soon-to-be mandated backup camera. Previously, they used analog cameras, connecting them via LVDS [low-voltage differential signaling] over coaxial cables. Now as they transition from analog to digital cameras, BroadR-Reach turns out to be a less costly solution. BroadR-reach lets multiple in-vehicle systems simultaneously access information over unshielded single twisted pair cable.
EE Times: I’ve always thought the infotainment network inside a car would be the first place where BroadR-Reach would move in. But aside from Land Rover, we haven’t seen many examples yet. Is that because MOST is too well established a bus in the in-vehicle infotainment network, and automakers are less inclined to replace it?
Lau: Our sense is that automotive OEMs will start embracing automotive Ethernet as more stuff – like heads-up displays, digital amplifiers, rear-seat entertainment, information clusters, etc. – begin hanging off the infotainment network. MOST will eventually run out of network bandwidth, because it’s based on a ring network. Its network architecture forces newly added clusters to share bandwidth. In contrast, Ethernet is based on a switched network — not a shared network like MOST – so that it can adapt to adding more complex, higher performance systems to the network.
EE Times: I hear often ADAS is what’s fueling carmakers to embrace Ethernet. But take an example of the number of cameras installed at the front end of a vehicle. They’re there to detect objects running in front of a vehicle, and to determine what they are. My understanding is that automotive OEMs wouldn’t like you to compress that video. If that’s the case, the 100Mbits offered by Ethernet is not going to help ADAS.
Lau: That’s a good question. We see there are two types of ADAS –passive and active. Ethernet is perfect for passive ADAS, which includes applications like parking assist. But for active ADAS, you’re correct, car OEMs want video to be lossless so that images captured can be sent uncompressed to an image cognition block, in which its algorithm determines what it is.
IEEE standard’s coming
EE Times: So, as I understand it, IEEE is putting together an automotive Ethernet standard, 802.3bw (also known as 100BASE-T1), slated to come out at the end of this year. Assume I’m a chip vendor. Shouldn’t I wait for the IEEE standard to get completed, rather than jumping the gun to become a member of OpenAlliance (which promotes BroadR-Reach)?
Lau: Nobody wants different flavors of automotive Ethernet. The industry has made it very clear that there should be one standard. BroadR-Reach is that standard and you’re assured that 802.3bw will be based on BroadR-Reach spec. They are equal.
EE Times: What about IP issues, then? I understand that even when I become a member of OpenAlliance, I still need to license Broadcom’s IP. I wonder if I can get a better deal if I wait for the IEEE standard, when its terms of conditions for licensing become available.
Lau: The licensing fees for the BroadR-Reach specification are the same, regardless if it is obtained via the OPEN Alliance SIG or the IEEE.
Once the IEEE 802.3bw standard is final, the same RAND (Reasonable and non-discriminatory) terms will apply. The Letter of Assurance is available on the