Explore Latency and TSN in Software-Defined Vehicles

Developing Software-Defined Vehicles poses numerous challenges to bring them into reality. One of the areas is managing the prioritized communication to the controllers and edge sensors in vehicle networks for applications such as software updates or data collection.  

While embracing the use of new software frameworks such as docker containers, SDVs are also driving increased use of Ethernet for connectivity of all network nodes within a vehicle network. Some of the nodes carry time sensitive data that has to reach their intended destinations promptly e.g. ADAS, object detection alerts. For time criticality to succeed, latency management becomes essential.  For such applications, TSN (Time-Sensitive Network) protocols have advanced the management of time critical data within an automotive network. Automotive architectures have begun to actively deploy TSN within their network. In the last few years, they have been predominantly used to manage infotainment.  But now they have gradually begun to manage critical vehicle communications.  

 

Understanding Latency in TSN 

Simply put, Latency in Time-Sensitive Networking (TSN) refers to the delay or time lapse between the initiation of a data transmission and its reception at the destination within a network. With SDVs, the quest for optimal performance and safety hinges on one critical factor, latency. The ability of a Software Defined Vehicle to make split-second decisions, avoid collisions, and seamlessly interact with its environment relies on low and predictable latency.  

Why Latency is Crucial in SDVs 

In Software-Defined Vehicles (SDVs), Time-Sensitive Networking (TSN) is essential for enhancing safety, similar to how features like forward collision warning and automatic emergency braking (AEB) reduce collisions. TSN can significantly contribute to safer SDVs. 

 

Understanding Low Latency in the Context of SDVs  

Real-Time Decision-Making 

SDVs operate in dynamic environments where decision-making within the span of microseconds is essential. Low latency ensures that critical connected vehicle data, such as sensor readings, camera object detection and other control commands and alerts, reach the vehicle's systems and enable swift responses to changing road conditions. 

Autonomous Driving Systems

Some cities have begun a trail for autonomous taxies. Autonomous by its very natures requires several stimuli to be evaluated to prevent collisions and proper recognition of obstacles and to avoid them.

Collision Avoidance 

In the pursuit of safety, Connected Vehicles heavily depend on systems that can swiftly detect and respond to potential collisions. V2X technology, utilizing DSRC (Dedicated Short-Range Communications), is being employed to avoid collisions and requires low-latency feedback for the car control systems to prevent accidents.

Interaction with Infrastructure 

SDVs are not isolated entities; they interact with smart infrastructure. Low latency is crucial for swift communication with traffic signals, road signs, and other intelligent systems, optimizing traffic flow and responsiveness to changing conditions.

 

How Excelfore’s Ethernet TSN Tech Impacts Software-Defined-Vehicles 

Guaranteed Latencies 

Excelfore’s Ethernet TSN stack provides the ability to manage latency when deployed into critical connected vehicle data transmissions. This assurance minimizes delays, ensuring that time-sensitive information traverses the network with precision. 

Prioritization of Critical Data 

When streams are tagged for priority, such as emergency commands, object detection from cameras, and sensor alerts, the TSN stack can ensure that these crucial pieces of data experience minimal latency.

Synchronization Across Systems 

Precise synchronization of clocks across SDV systems is facilitated by TSN and is performed through the use of gPTP (generalized precision time protocol, 802.1AS). This synchronization is pivotal for orchestrating actions among diverse components, contributing to the overall efficiency and safety of the vehicle. 

Dynamic Network Adaptation 

Advanced In Vehicle Network support offered by Excelfore’s TSN for dynamic network adaptation enables communication networks to be modified in real-time. This adaptability ensures that the network can be managed for efficiency and rapid responsiveness, even in the face of varying workloads. 

Excelfore's TSN stack has been deployed in various automotive systems for over a decade across varied platforms, operating systems and has been AVNU certified for end points and bridges. This makes the Excelfore TSN stack as one of the very few to have certification for compliance.  Click here to know more about Excelfore’s TSN tech. 

 

Conclusion 

In the era of Software-Defined Vehicles (SDVs), the centrality of Time-Sensitive Networking (TSN) in managing latency, the temporal delay in data transmission, is well established. Low latency communication helps SDVs in executing real-time decisions, averting collisions, and seamlessly interacting with their environment. TSN offers guaranteed latencies but also prioritizes critical data, synchronizes various vehicle systems, and dynamically adapts to the exigencies of network demands. This technology enhances vehicle safety and efficiency, mirroring the impact of advanced safety features in reducing collisions in modern automobiles.