Continental details in-car Ethernet plans
The increasing bandwidth requirements, driven by next-generation camera-based driver assistance systems in the first place, make Ethernet the ideal means for data networks in vehicles, Continental said. With a robust bandwidth of 100 Mbit/s and the usage of simple, cost-effective unshielded two-wire copper cable, Ethernet will connect all relevant ECUs, antennas and sensors, the company explained. With this position, Continental was among the first tier ones to commit to Ethernet; the company already announced support for Ethernet earlier this year.
Now Continental has submitted a kind of roadmap for the roll-out of Ethernet. In the first step, the electronics provider plans to equip the Interior and chassis and safety domains with Ethernet since in these domains wiring is a relatively easy task. Later, the cars could be networked entirely with Ethernet, doing away with technologies today in use but with much lower performance. In terms of introducing Ethernet, the relatively long automotive design cycles apply. First products will be available in 2015. Gradually, Ethernet will conquer all automotive domains. "Around 2020, we can imagine having the first pre-development projects with Ethernet in all domains", Continental writes in a press release.
Ethernet would make a multitude of benefits available to carmakers – benefits that other segments of the IT world already could use for decades but were not accessible for in-car networking designers because of the extreme EMC requirements in vehicles. "Ethernet will help to reduce the total vehicle costs and at the same time increase functionality," explained Continental board member Helmut Matschi.
In a cost comparison against MOST, Ethernet would allow one to implement solutions 15 to 20% cheaper, Continental said. The comparison included the electric and electronic components as well as the cabling. And pricing is not the only advantage of Ethernet over MOST. The optical networks used in MOST applications are much more difficult to handle because of their relatively high diameter and bending radius. "Handling MOST cables in a car is a nightmare," said a design engineer who asked for anonymity.
From Continental’s perspective, Ethernet will affect the networking topology in cars. Since today’s 100 MBit/s Ethernet anticipates a star topology instead of a bus topology, cars will need to be equipped with a number of switches. In part, these will be integrated into ECUs or other domain controllers. Further, there will be a central gateway with an Ethernet interface. This gateway also terminates existing CAN, FlexRay and MOST network segments and connects them to the Ethernet world. In this context, Continental already is talking of IP communication – the communication scheme in widespread use in commercial and technical networking.
One of the first components for in-car Ethernet communications has already been developed by Continental development partner Kathrein. This is an intelligent module with multiple antennae for wireless communications between car and infrastructure as well as for the communication between the car and any computers or smartphones inside the vehicle. The module also contains the related receiver and transmitter circuitry. All data received can be digitized and be fed onto the internal IP based network for further processing. This, Continental said, is an important building block to turn the vision of "Always On" for cars into reality.