Le blog À propos Automotive Ethernet Drives Invehicle Connectivity Revolution

In the grand blueprint of the automotive industry, software-defined vehicles (SDVs), autonomous driving technologies, and continuously evolving consumer experiences are converging at an unprecedented pace. A scalable, high-speed, and reliable in-vehicle network is no longer optional but a critical factor determining the competitiveness of future vehicles. Automotive Ethernet, as an emerging in-vehicle network technology, is gradually becoming the cornerstone of modern vehicle architecture. Particularly when combined with Time-Sensitive Networking (TSN) technology, automotive Ethernet provides original equipment manufacturers (OEMs) with the bandwidth, flexibility, and interoperability needed to support next-generation vehicle systems.

Automotive Ethernet didn't emerge out of thin air but represents a deeply customized and optimized version of standard Ethernet technology tailored for automotive-specific requirements. Compared to traditional in-vehicle communication protocols (such as CAN, LIN, or FlexRay), Ethernet supports higher data transmission rates and adopts IP-based communication, providing a more powerful platform for data exchange between various electronic control units (ECUs) within vehicles.

However, unlike CAN and FlexRay, Ethernet doesn't inherently possess deterministic bandwidth or latency characteristics. While a two-second buffering delay when watching online videos might not cause significant user discomfort, even brief delays in a vehicle's rearview camera system could lead to serious accidents. To address Ethernet's limitations in determinism, the IEEE 802.1 working group developed a series of Time-Sensitive Networking (TSN) standards. These standards add time synchronization, traffic scheduling, and redundancy capabilities to Ethernet, enabling it to meet the requirements of safety-critical and connected vehicle applications.

• High Bandwidth: Automotive Ethernet supports data transmission rates ranging from 10 Mbps to 10 Gbps or higher, meeting the growing data transmission demands within vehicles.
• Cost-Effective Cabling: The use of single-pair twisted-pair cables (such as 100BASE-T1, 1000BASE-T1) significantly reduces cable weight and cost, which is crucial for automakers pursuing lightweight design and cost control.
• IP Addressing: Using Internet Protocol (IP) addressing provides a universal and interoperable addressing structure for devices on in-vehicle networks. This is essential for the cloud connectivity expected in software-defined vehicles (SDVs).

• Time Synchronization: All devices on the network can synchronize to a common reference clock, ensuring precision and consistency in data transmission.
• Traffic Classification and Shaping: Message traffic can be organized into different categories to achieve smooth and reliable audio/video operations.
• Deterministic Shaping: Through time-aware shaping and preemption technologies, critical traffic for safety-critical and vehicle control functions can be guided, achieving deterministic and guaranteed latency, typically with end-to-end precision in microseconds.
• Redundancy: Networks can be built with redundancy so that the loss of any link (or even any network node) won't interfere with message traffic between remaining links and nodes.

As vehicles integrate more ECUs, sensors, cameras, and infotainment systems, traditional bus protocols are increasingly unable to meet growing bandwidth demands. Ethernet provides a unified and scalable platform, allowing OEMs to consolidate multiple communication domains into a single backbone network. This integration not only simplifies vehicle electrical architecture but also reduces wiring harness complexity and weight.

Automotive Ethernet operates in full-duplex mode, allowing data to be transmitted simultaneously in both directions over a single twisted pair. This feature, absent in buses like CAN or LIN, increases data throughput and reduces cable weight in vehicles. Full-duplex communication is crucial for applications requiring high bandwidth and low latency, such as ADAS and autonomous driving.

ADAS, autonomous driving functions, and high-resolution infotainment systems generate up to gigabytes of data per second. Ethernet's bandwidth can efficiently handle this data, enabling smoother and safer driving experiences. For instance, autonomous driving systems need to process data from multiple sensors in real-time to make accurate decisions. Automotive Ethernet provides sufficient bandwidth to support these data-intensive applications.

Ethernet is inherently IP-friendly, enabling easy communication with cloud services, OTA platforms, V2X, and mobile devices. This integration is crucial for software-defined vehicles (SDVs), which require frequent data exchange and software updates with the cloud. Automotive Ethernet provides SDVs with a reliable and secure communication channel.

Automotive Ethernet is governed by IEEE 802.3 and IEEE 802.1 TSN extensions, ensuring cross-vendor compatibility. This is essential for OEMs integrating solutions from multiple tier-one suppliers and software providers. Standardization and interoperability reduce integration complexity and allow OEMs to select optimal components and solutions.

Not all Ethernet in vehicles is the same. Key standards include:

• 100BASE-T1 (IEEE 802.3bw): Entry-level bandwidth suitable for body electronics and ADAS sensors.
• 1000BASE-T1 (IEEE 802.3bp): Mid-level bandwidth suitable for infotainment systems and high-resolution cameras.
• 10GBASE-T1 (IEEE 802.3ch): High-performance backbone suitable for autonomous driving and zone controllers.

These standards allow OEMs to design zonal architectures where fewer, smarter gateways manage data across vehicle domains. Zonal architectures can reduce wiring harness complexity and weight while improving overall vehicle performance.

Real-time fusion of camera, radar, and lidar data requires deterministic Ethernet TSN for safe decision-making. For example, automatic emergency braking systems need to process data from multiple sensors in real-time to detect potential collisions and take appropriate action. Ethernet TSN provides the required low latency and high reliability to ensure system safety.

HD streaming, gaming, and mirroring require AVB and gigabit Ethernet. Automotive Ethernet provides sufficient bandwidth to support these data-intensive applications, delivering rich entertainment experiences for passengers.

OEMs rely on Ethernet to quickly and securely deliver large software packages, which is crucial for SDVs. OTA updates allow OEMs to improve and update software throughout a vehicle's lifecycle without recalls. Automotive Ethernet provides a reliable and secure communication channel for OTA updates.

Connecting ECUs via zone hubs over high-speed Ethernet backbones reduces wiring complexity and cost. Zonal architectures divide vehicle electronic systems into multiple zones, each managed by one or more zone controllers. Zone controllers communicate via Ethernet backbones, reducing wiring harness complexity and weight while improving overall vehicle performance.

• Determinism for safety-critical systems: TSN adoption is crucial. OEMs must ensure their automotive Ethernet networks meet the low-latency and high-reliability requirements of safety-critical applications.
• Security risks: IP-based systems must incorporate encryption, authentication, and intrusion detection mechanisms. As vehicles become more connected, they face increasing cybersecurity risks. OEMs need appropriate security measures to protect vehicles from cyberattacks.
• Testing and validation complexity: Gigabit networks require new simulation and diagnostic tools. Automotive Ethernet's complexity presents new challenges for testing and validation. OEMs need new tools and techniques to ensure proper network operation.
• Interoperability: During transition, OEMs must integrate Ethernet with existing CAN/LIN systems. Automotive Ethernet must interoperate with legacy CAN and LIN networks in vehicles. OEMs must ensure seamless integration.

Rather than replacing CAN, it's more about extending it. Individual ECUs or smart sensors may remain on CAN buses for some time. However, Ethernet provides higher bandwidth, deterministic performance, and scalability for backbone networks connecting high-performance computers and multiple CAN bus clusters, suitable for ADAS and SDVs. Due to its technical and cost advantages, automotive Ethernet may eventually replace CAN over time through multi-generation designs.

100BASE-T1, 1000BASE-T1, and 10GBASE-T1—each serving different vehicle domains.

• 802.1AS (gPTP): For clock alignment
• 802.1Qav: (Credit-based shaper) For traffic classification and shaping
• 802.1Qb: (Time-aware shaper) For deterministic latency and bandwidth for critical traffic
• 802.1Qbu/802.3br: (Frame preemption) For protecting priority traffic from low-priority long-frame traffic
• 802.1Qci: (Ingress policing), guard bands, VLAN PCP priorities, per-port rate limiting.
• 802.1CB: (Frame replication and elimination for reliability) For traffic deduplication and automatic switching when building redundant network links

BMW, Volkswagen, and Tesla have been early pioneers—integrating Ethernet into infotainment, ADAS, and OTA platforms. More OEMs now use automotive Ethernet in certain parts of their product lines.

Automotive Ethernet, combined with Time-Sensitive Networking (TSN), SOME/IP, and DoIP, forms the backbone of future connected, autonomous, and software-defined vehicles. OEMs adopting it today are building future-proof platforms.