Till Steinbach: Beware of the Hidden! Analyzing the Influences of Background Traffic on Competing Standards for In-Car Communication Based on Ethernet
Vortrag und Demo für die IEEE LCN 2015
- https://inet.haw-hamburg.de/events/inet-seminar/till_steinbach_beware_of_the_hidden
- Till Steinbach: Beware of the Hidden! Analyzing the Influences of Background Traffic on Competing Standards for In-Car Communication Based on Ethernet
- 2015-10-21T16:00:00+02:00
- 2015-10-21T18:30:00+02:00
- Vortrag und Demo für die IEEE LCN 2015
Oct 21, 2015 from 04:00 PM to 06:30 PM (Europe/Berlin / UTC200)
Real-time Ethernet is expected to become the core technology of future in-car communication networks. Following its current adoption in subsystems for info- and entertainment, broadband Ethernet promises new features in the core of upcoming car series. Its full potential will enfold when deploying Ethernet-based backbones that consolidate all automotive domains on a single physical layer at increased bandwidth but reduced complexity and cost. In such a backbone, traffic with a variety of real-time requirements and best-effort characteristics will share the same physical infrastructure. However, certain applications like online diagnosis, data- or firmware updates, and access to off-board backends will introduce bursty high traffic loads to the sensitive core of the cars communication network.
In this work, we analyze the robustness against cross-traffic of real-time Ethernet protocols. Based on a realistic in-car scenario, we demonstrate that background cross-traffic can have significant impact on in-car backbone networks—even for real-time protocols with strict prioritization. By comparing the real-time approaches Ethernet AVBs asynchronous credit based shaping with the time-triggered and rate-constrained traffic classes of Time-triggered Ethernet (AS6802) we quantify how different media access policies suffer from low priority bursts of applications such as diagnosis, online updates or backend-based services. Our simulation study of a realistic in-car backbone design and traffic model reveals that in a realistic in-car network design, cross-traffic may increase end-to-end latency by more than 500% while the jitter can become 14 times higher than for a network without background tasks. We discuss ways to mitigate these degrading effects.