April 28, 2021
Back to the Future – Automotive network run at speed of 10Gbps
By
Amir Bar-Niv, VP of Marketing, Automotive Business Unit, Marvell
In the classic 1980s “Back to the Future” movie trilogy, Doc Brown – inventor of the DeLorean time machine – declares that "your future is whatever you make it, so make it a good one.” At Marvell, engineers are doing just that by accelerating automotive Ethernet capabilities: Earlier this week, Marvell announced the latest addition to its automotive products portfolio – the 88Q4346 802.3ch-based multi-gig automotive Ethernet PHY.
This technology addresses three emerging automotive trends requiring multi-gig Ethernet speeds, including:
- The increasing integration of high-resolution cameras and sensors
- Growing utilization of powerful 5G networks
- The rise of Zonal Architecture in car design
1.
Cameras are now upgrading from resolutions of 720p to 1080p, moving to 4K and even 8K within a few years. In addition, the pixel size (color depth) has increased to 16 and 24 bits per pixel, with the refresh rate moving to 60 frames per second. The result? The bandwidth needed to carry the high-resolution video will need to grow correspondingly. While 1Gbps used to be sufficient, there are now many use cases that require data rates up to 10Gbps and beyond (see Figure 1).
Figure 1
Infotainment and high-resolution displays are also driving the need for high-speed video over the in-vehicle backbone. At last year’s CES in Las Vegas (remember those big trade shows, before Covid?) the Byton M-Byte's jumbo, 48-inch interior screen grabbed headlines. But the revolution in car displays is really just starting. Dashboard displays with integrating touchscreen, controls and ambient lighting in complex 3D forms will be common features in future cars. Holograms and Changeable Surface Textures are new technologies that automotive designers are integrating into display screens.
Technologies such as Apple CarPlay and Android Auto, as well as Google-based infotainment suites, effectively transform these displays into extensions of our smartphones and smart homes, including support for video-conferencing that combines high-res displays and cameras.
- The cost of sensor modules
- The heat dissipation that pre-processing units in the sensor create, which degrades sensor performance.
- The latency created by the pre-processing algorithms (improve detection and response time).
Figure 2
To support this trend, these sensors are already upgrading from 100Mbps to 1Gbps Ethernet links, and within a few years are expected to require multi-gigabit rates.
2.
Until now, vehicles had to communicate via a distant server. With 5G, vehicles can communicate directly with each other, exchanging key information about accidents, road conditions and other alerts. This 5G network is critical to autonomous transportation, which is designed to be safer, more efficient, and more sustainable. It will also offer passengers a rich experience in the car and better ways to use their time while on the road. This includes using interactive applications, watching movies, playing games or preparing for meetings as easily as they do at home.
Figure 3
3.
That’s because many of today’s new vehicles are still built around the concept of Domain Architecture, where extensive cable harnesses connect independent domains such as Body, Telematics, ADAS, Infotainment and Powertrain directly to components that are spread all over the car. Figure 4 offers a simplified diagram of a typical harness system.
Figure 4
Shedding the constraints of traditional wired harnesses, the most advanced vehicle designers are shifting toward Zonal Architecture, which leverages Ethernet as the backbone protocol between the car’s different zones. To support this concept, each zone of the car includes a Zonal Gateway – a switch that utilizes Ethernet to convert and aggregate the different domains and protocols, while preserving each protocol’s desired performance and quality of service (QoS). As Figure 5 illustrates, Zonal Architecture dramatically streamlines automotive wiring requirements, reducing cable, labor and energy costs.
Figure 5
With a backbone that can leverage the speed and the benefits of Ethernet (switching, QoS, security, virtualization) and the growing computing power of the latest CPUs, many OEMs are now gravitating toward a central processing architecture (see Figure 6).
Figure 6 – Zonal architecture with Central Processing
Along with the central processing comes the need for central storage, to store the most relevant data in a way that is secure, fast, easy and reliable to access.
To be able to aggregate the high bandwidth data of each zone over the zonal architecture, the Ethernet backbone needs to support data speeds of 10Gbps and higher.
Marvell track record with Multi-gig Ethernet
Marvell was the first company to introduce 10G Automotive Ethernet PHY (AQV107), in 2018, which supported 2.5G, 5G and 10Gbps speeds over automotive cables. Next, Marvell supported the development of a new IEEE standard for Multi-gigabit Ethernet Automotive PHY (IEEE’s 802.3ch), and is now sampling to customers the 88Q4346, IEEE compliant 10GBASE-T1 PHY.
In addition, the new line of automotive Ethernet switches that Marvell introduced in 2020 included multi-gigabit ports. The 88Q5072 is a highly integrated 11-port managed secured switch that support 2.5Gbps and 5Gbps ports, and the 88Q6113 supports two ports of 10Gbps.
标签： Automotive Ethernet PHY, automotive Ethernet switches, domain architecture IVN, multi-gig automotive Ethernet, Multi-gig Ethernet
