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Crosstalk in Automotive Networking

Published Date
Author Cadence PCB Solutions

Key Takeaways

  • Some automotive network protocols are the local interconnect network (LIN), controller area network (CAN), media-oriented system transport (MOST), and FlexRay. 

  • The automotive Ethernet offers a cost-effective, lightweight communication solution in automobiles using single unshielded twisted-pair (UTP) cabling. 

  • The bundling of cables in an automotive communication network can initiate crosstalk interference.

 Automotive networking

The future of the automobile industry lies in autonomous vehicles. For cyber-secured connectivity, the automotive industry uses Ethernet networking. Automotive Ethernet networks are a necessary part of in-vehicle infotainment, diagnostics, and the connection of remote sensors. Automotive Ethernet networks offer more benefits than commonly-used networking protocols such as controller area networks (CANs) or FlexRay. The crosstalk in networking is also comparatively less for automotive Ethernet networks. In this article, we will discuss automotive network protocols and the crosstalk interference affecting automotive networks.  

Automotive Networking Will Become Increasingly Critical

Conventional internal combustion engine vehicles are being replaced by autonomous vehicles. In fact, the growing demand for autonomous vehicles is so high that most of the leading automobile manufacturers have advanced into the autonomous vehicle production sector. Autonomous vehicles rely on electronic systems rather than mechanical or hydraulic systems. The size, weight, and reliability of the electronic control units used in autonomous vehicles are better than their conventional counterparts.

The electronic control units in autonomous vehicles are modular stand-alone units that communicate with each other and with a central system. The in-vehicle network needs to be capable of transferring data at a faster rate and lower latency than existing solutions for driver safety. Automotive networks should be capable of handling heavy data traffic with greater bandwidth. Different protocols have been developed exclusively for automotive networking. We will discuss a few of them in the upcoming section. 

Automotive Networking Protocols

Some automotive network protocols are the local interconnect network (LIN), controller area network (CAN), media-oriented system transport (MOST), and FlexRay.

Local Interconnect Network (LIN) - LIN is a serial network protocol used in automobiles to communicate between various components in vehicles. It is a low-cost networking standard used in automobiles that offer low-end multiplexed communication. The LIN bus utilizes a commander/responder approach for communication and is implemented with a single wire.

Controller Area Network (CAN) - CAN is a balanced differential two-wire serial communication protocol that addresses the need for high bandwidth in automotive networking. It allows the electronic control units in autonomous vehicles to share control data seamlessly. CAN is a priority-driven communication protocol.

Media-Oriented System Transport (MOST) - This is a high-speed multimedia network used in automobiles for the distribution of information within vehicular components. A MOST bus uses optic fiber links as the primary communication medium.

FlexRay - FlexRay is a serial communication protocol that offers reliable communication in safety-critical systems and adaptive cruise control of automobiles. High data rates, high data transmission capabilities, and time-triggered communications are some of the advantages of FlexRay.

Automotive Ethernet - Previously mentioned automotive networking protocols don’t offer everything vehicles might need. Present-day vehicles require vehicle-to-everything (V2X) connectivity along with greater bandwidth. Automotive Ethernet protocol satisfies automotive networking demands and is widely adopted by the automotive industry. The automotive Ethernet is a fast four-wire standard communication protocol that offers protection for in-vehicle systems. Automotive Ethernet offers a cost-effective, lightweight communication solution in automobiles using single unshielded twisted-pair (UTP) cabling. 

Crosstalk in the Networking Used in Automobiles

The automotive high-speed communication bus is designed to operate in harsh electromagnetic environments. The emissions from automotive networks should not interfere with on-board or off-board devices. The automotive network should also be insusceptible to external noise. If the automotive data network becomes vulnerable to electromagnetic issues, it will affect the safety and reliability of the vehicle.

Considering all these aspects, electromagnetic compatibility is given top priority in automotive network design. Electromagnetic interference constraints are introduced into the design of the electrical and electronic architecture of automobiles to achieve electromagnetic compatibility.

Crosstalk in automotive networking is one of the common failure modes. Crosstalk is undesirable, as it impacts the safety of the vehicle. The crosstalk phenomenon causes unwanted coupling of energy from one line to another in the communication buses present in automobiles and degrades the signal integrity of the automotive data network.

The bundling of cables in an automotive communication network can initiate crosstalk interference and can be observed as definite dB values of alien crosstalk or power sum alien near-end crosstalk. The multiple pairs in the wiring harness for data communication are detrimental to the crosstalk immunity of automotive networks. A single twisted pair cable—which is the most common type of Ethernet cable—can bring down the effect of crosstalk.

The crosstalk in networking that establishes communication in autonomous vehicles significantly influences the functioning of the electrical and electronic architecture of vehicles. Compared to other communication protocols, the automotive Ethernet provides better performance, signal integrity, and crosstalk immunity.

Cadence software offers a variety of IPs to support automotive Ethernet applications. Subscribe to our newsletter for the latest updates. If you’re looking to learn more about how Cadence has the solution for you, talk to our team of experts.