Overcoming Bandwidth Issues In Self-Driving Vehicles

Why harnessing the low cost/high bandwidth of Ethernet in autonomous vehicles makes sense.

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Drivers are already getting used to what used to be “cool new features” that have now become “can’t live without” technologies, such as the backup camera, blind spot alert or parking assist. Each of these technologies stream information, or data, within the car, and as automotive technology evolves, more and more features will be added. But when it comes to autonomous vehicles, the amount of technology and data streams coming into the car to be processed increases exponentially.

Autonomous vehicles gather multiple streams of information/data from sensors, radar, radios, IR sensors and cameras. This goes beyond the current Advanced Driver Assist Systems (ADAS) or In-Vehicle Infotainment (IVI). The autonomous car will be acutely aware of its surroundings, running sophisticated algorithms that will make decisions in order to drive the vehicle. However, self-driving cars will also be processing vehicle-to-vehicle communications, as well as connecting to a number of external devices that will be installed in the highway of the future as automotive communication infrastructures develop. All of these features and processes require bandwidth-and a lot of it: Start the car; drive; turn; red light, stop; – PEDESTRIAN – BRAKE! This would be a very bad time for the internal vehicle networks to run out of bandwidth.

Add to the driving functions the simultaneous infotainment streams for each passenger, vehicle Internet capabilities, etc. and the current 100 megabits-per-second (mbps) 100BASE-T1 Ethernet bandwidth used in automotive is quickly strained. This is paving the way (pun intended) for 1000BASE-T1 Gigabit Ethernet (GbE) for automotive networks. Ethernet has long been the economical volume workhorse with millions of miles of cabling in buildings the world over. Therefore, the IEEE 802.3 Ethernet Working Group has endorsed iGbE as the next network bandwidth standard in automotive.

From Car-jacking to Car-hacking—Security Critical
Another major factor for automotive networking is security. In addition to the many technology features and processes needed for driving and entertainment, security is a major concern for cars, especially autonomous cars. Science fiction movies where cars are hacked overriding the driver’s capabilities are scary enough, but in real life would be beyond a nightmare. Automotive security to prevent spyware, whether planted from a rogue mechanic or roving hack, will require strong authentication to protect privacy and passenger safety. Cars of the future will be able to reject any devices added that aren’t authenticated, as well as any external intrusion through the open communication channels of the vehicle.

This is why companies like Marvell have joined with organizations like IEEE to help create open standards, such as GbE for automotive, to keep moving automotive technologies forward. (For additional background or information on this topic view the IEEE 2014 Automotive Day presentation by Alex Tan on the Benefits of Designing 1000BASE-T1 into Automotive Architectures.)

Technology to Drive Next-Generation Automotive Networking
Next generations of automotive Ethernet Networking technology are capable of taking what used to be the separate domains of the car — infotainment, driver assist, body electronics and control — and connecting them together to provide a high-bandwidth standards-based data backbone for the vehicle. For example, new 1000BASE-T1 automotive Ethernet PHY transceivers compliant with the IEEE 802.3bp 1000BASE-T1 standard are already on the market. These types of products support the market’s highest in-vehicle connectivity bandwidth and are designed to meet the rigorous EMI requirements of an automotive system.

The 1000BASE-T1 standard allows high-speed and bi-directional data traffic and in-vehicle uncompressed 720p30 camera video for multiple HD video streams, including 4K resolution, all over a lightweight, low-cost single pair cable. Low-power PHY devices can also support 100BASE-T1 and compressed 1080p60 video for infotainment, data transport and camera systems. In addition, 7-port Ethernet switches are also now available to support these higher automotive networking standards to make it easier to keep up with the additional bandwidth demands for the connected vehicle.

Harnessing the low cost and high bandwidth of Ethernet brings many advantages to next-generation automotive architecture, including the flexibility to add new applications. In other words, allowing the possibility to build for features that haven’t even been thought up yet. Because while the car of the future may drive itself, it takes a consortium of technology leaders to pave the way.