Automotive Ethernet
Published: 2023-11-22 10:22:35

Hello readers, 👋😍 My name is Nagaraj B H and I work at Luxoft India  as a junior software engineer. Luxoft gave me several opportunities to work on many projects that made me discuss important strategies for the development of the Ethernet protocol. Here we talk about Automotive Ethernet in detail.
**Introduction:**
The internal network of vehicles is developing rapidly thanks to the development of autonomous driving and connectivity, which are driving the automotive industry forward. More features must be supported to improve efficiency, safety and of course the driving experience. Therefore, the requirements for data bandwidth and the number of cables; and factors such as complexity, flexibility and cost-effectiveness become even more challenging. To enable autonomous driving, the combination of technologies must be well integrated into the car. This includes long-range radar, short/medium-range radar, LIDAR, cameras, ultrasonic sensors and GPS, all operating at different data rates and communication protocols. As a result, these decentralized networks are becoming more and more centralized network architectures. Automotive Ethernet is a special form of Ethernet network adapted to vehicles, which enables fast data transmission between different car components. It is designed to meet car-specific requirements such as electromagnetic compatibility and uses advanced Phy receivers to reduce cable costs. This system enables higher transfer rates compared to traditional automotive networks and facilitates the integration of Internet Protocol (IP) technologies, improving operational security and cyber security.
 **Why Automotive Ethernet? :**
Automotive Ethernet is a new physical layer standard that uses the Ethernet standard as an in-vehicle networking technology. It offers high protection, less cable and high data transfer speed. High noise immunity and minimal cabling are two key innovations that helped bring Ethernet into the vehicle. Without high immunity, the standard Ethernet 100Base-T and 100Base-TX we know would not withstand the harsh electromagnetic environment of the vehicle. picture description.
 
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Figure 1. Dual simplex PHY I/O vs full duplex PHY I/O Figure 1 shows a high-level overview of the physical (PHY) layer. As you can see, standard Ethernet 100Base-Tx is a dual simple configuration with two twisted pairs. In comparison, Automotive Ethernet 100Base-T1 is a single twisted-pair bidirectional link capable of transmitting 100 megabits per second (Mbps) in each direction. This means that 200 Mbps aggregate communication is theoretically possible between nodes. The same improvement can be seen with 1000Base-T1. The difference is huge when comparing Ethernet speeds to CAN, CAN-FD, LIN and FlexRay speeds which run at bits per second or kilobits per second. This clearly shows the benefits of Ethernet in the automotive industry as it can meet the higher bandwidth demand of autonomous vehicles (AV).
 
**Ethernet vs. Automotive Ethernet:**
Standard Ethernet, widely used in LANs and WANs since its release in 1980 and IEEE standardization in 1983, was initially unsuitable for use in the automotive industry because it was susceptible to noise and interference. However, Automotive Ethernet is specifically tailored for vehicles to meet these challenges. The main difference between regular Ethernet and Automotive Ethernet is in their physical layers. Automotive Ethernet uses single twisted pair cables for two-way data transmission, which are lighter and can be either shielded or unshielded, as opposed to standard Ethernet twisted pair cables. This adaptation reduces weight by 30% compared to traditional CAN/LIN harnesses and is less sensitive to automotive environmental issues. Automotive versions of Ethernet, such as 100Base-T1 and 1000Base-T1, operate as switched networks optimized for the data transmission needs of vehicles. Another variant, 10Base-T1S, works as a multi-drop bus like CAN networks. These features are essential to meet the increased bandwidth and lower latency requirements of today's and today's vehicles. Unlike Diagnostics over IP (DoIP), which uses a standard 100Base-TX Ethernet connection to the vehicle's SAE J1962 diagnostic interface, Automotive Ethernet is a special solution. It meets the stringent requirements of in-vehicle communication networks, paving the way for better connectivity and advanced vehicle functions.
**Key features and specifications of Automotive Ethernet:** 
**Point-to-point network:** Automotive Ethernet connects nodes directly, unlike bus technology. 
**Switch Integration:** Allows multiple ECUs to communicate and control traffic using physical addresses.
**Standards (100Base-T1 and 1000Base-T1):** Designed specifically for automotive networking requirements.
**Cable:** 100Base-T1 uses an unshielded single twisted pair for 100 Mbps data, supporting audio-video bridging (AVB). 
**Audio Video Bridging (AVB):** Standards for better synchronization, lower latency and reliability in Ethernet networks.
**Limitations of CAN/CAN-FD:** Not suitable for automotive audio-video applications due to 1-8 Mbps capacity. 
**Cost-effectiveness:** Automotive Ethernet, with an initial speed of 100 Mbps, is cheaper than other protocols. 
**Energy efficiency:** lighter cables reduce energy consumption, reduce connection costs by up to 80% and reduce weight by 30%.