Exploring the worst-case timing of Ethernet AVB for industrial applications

Diemer, Jonas; Rox, Jonas; Ernst, Rolf; Chen, Feng; Kremer, Karl-Theo; Richter, Kai

doi:10.1109/iecon.2012.6389389

Cited by 12 publications

(4 citation statements)

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“…A possible candidate could be camera traffic. Experiments with realistic automation control traffic show that this approach is reasonable and achieves the required latency bounds required for automotive applications [9] [19]. For less time-critical traffic or traffic that is not that well defined, a "less-than worst-case" design principle is then possible on the lower priorities, just like found in ECU or CAN bus designs.…”

Section: Mac Address Managementmentioning

confidence: 92%

“…However, this is only possible if the switch allows a partitioning of memory that explicitly ties memory partitions to individual priorities or queues and ports. The effects of different schedulers on delay and thus generated backlog for switched Ethernet have been studied extensively in [21,20,18,6,9]. The importance thus not only is on the appropriate port scheduler but also on the fact if and how buffer space can be reserved for specific queues that transport high critical streams to ensure freedom from interference.…”

Section: Mac Address Managementmentioning

confidence: 99%

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Invited - Towards fail-operational ethernet based in-vehicle networks

Mostl

Thiele

Ernst

2016

Proceedings of the 53rd Annual Design Automation Conference

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In the future, vehicles are expected to act more and more autonomously. The transition towards highly automated and autonomous driving will push the safety requirements for in-vehicle networks. Such networks must support isolation between mixed-critical traffic (e.g. critical control and noncritical infotainment) and must be fail-operational. This paper will present new concepts and mechanisms to achieve these goals in Ethernet-based networks. It will cover advanced topics such as software defined networking (SDN) to implement isolation, fault recovery, and controlled degradation, e.g. to maintain (degraded) operation until the driver takes over or to reach a safe stop.

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Section: Mac Address Managementmentioning

confidence: 92%

Section: Mac Address Managementmentioning

confidence: 99%

Invited - Towards fail-operational ethernet based in-vehicle networks

Mostl

Thiele

Ernst

2016

Proceedings of the 53rd Annual Design Automation Conference

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“…Existing methods can be divided into four kinds: Compositional Performance Analysis (CPA), Network Calculus (NC), Trajectory Approach (TA) and miscellaneous methods. The first set of papers concern CPA method [ 23 , 24 , 25 , 26 , 27 ]. CPA is based on an iterative approach to seek the maximal stable delays in a busy period according to worst-case arrival sequences of all interfering flows.…”

Section: Introductionmentioning

confidence: 99%

Impact Analysis of Flow Shaping in Ethernet-AVB/TSN and AFDX from Network Calculus and Simulation Perspective

Zhao

2017

Sensors

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Ethernet-AVB/TSN (Audio Video Bridging/Time-Sensitive Networking) and AFDX (Avionics Full DupleX switched Ethernet) are switched Ethernet technologies, which are both candidates for real-time communication in the context of transportation systems. AFDX implements a fixed priority scheduling strategy with two priority levels. Ethernet-AVB/TSN supports a similar fixed priority scheduling with an additional Credit-Based Shaper (CBS) mechanism. Besides, TSN can support time-triggered scheduling strategy. One direct effect of CBS mechanism is to increase the delay of its flows while decreasing the delay of other priority ones. The former effect can be seen as the shaping restriction and the latter effect can be seen as the shaping benefit from CBS. The goal of this paper is to investigate the impact of CBS on different priority flows, especially on the intermediate priority ones, as well as the effect of CBS bandwidth allocation. It is based on a performance comparison of AVB/TSN and AFDX by simulation in an automotive case study. Furthermore, the shaping benefit is modeled based on integral operation from network calculus perspective. Combing with the analysis of shaping restriction and shaping benefit, some configuration suggestions on the setting of CBS bandwidth are given. Results show that the effect of CBS depends on flow loads and CBS configurations. A larger load of high priority flows in AVB tends to a better performance for the intermediate priority flows when compared with AFDX. Shaping benefit can be explained and calculated according to the changing from the permitted maximum burst.

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“…In this paper, we focus on the latter. A discussion about the gap between the observed latencies from a simulation and the latency guarantees from a formal CPA analysis in the Ethernet context can be found in [6].…”

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confidence: 99%

Formal worst-case timing analysis of Ethernet TSN's time-aware and peristaltic shapers

Thiele

Ernst

Diemer

2015

2015 IEEE Vehicular Networking Conference (VNC)

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Ethernet is considered as a future communication standard for distributed embedded systems in the automotive and industrial domains. A key challenge is the deterministic low-latency transport of Ethernet frames, as many safety-critical real-time applications in these domains have tight timing requirements. Time-sensitive networking (TSN) is an upcoming set of Ethernet standards, which (among other things) address these requirements by specifying new quality of service mechanisms in the form of different traffic shapers. In this paper, we consider TSN's time-aware and peristaltic shapers and evaluate whether these shapers are able to fulfill these strict timing requirements. We present a formal timing analysis, which is a key requirement for the adoption of Ethernet in safety-critical real-time systems, to derive worst-case latency bounds for each shaper. We use a realistic automotive Ethernet setup to compare these shapers to each other and against Ethernet following IEEE 802.1Q. I. INTRODUCTION Packet-switched Ethernet will be used in next-generation automotive communication architectures, as traditional buses such as CAN or FlexRay cannot keep pace with the increasing bandwidth and scalability requirements of advanced driver assistance and infotainment systems. As a switched network, Ethernet provides a scalable, high-speed, and cost-effective communication platform, which allows arbitrary topologies. However, as each switch output port is a point of arbitration, Ethernet exhibits a complex timing behavior, which must be verified thoroughly before it can be used in timing-and safety-critical systems. Ethernet is anticipated to serve as an in-vehicle communication backbone, where is must be able to transport traffic streams of mixed-criticality. This requires quality of service (QoS) mechanisms, in order to provide deterministic timing guarantees to critical traffic. Standard Ethernet following IEEE 802.1Q introduced 8 traffic classes. These classes can be used to prioritize traffic, which is typically implemented by a static-priority non-preemptive (SPNP) scheduler at each output port in each switch and endpoint. This limited number of classes requires that multiple traffic streams share a class. Traffic within a shared class is usually scheduled in FIFO order. Ethernet AVB [1] introduced standardized traffic shaping by using a credit-based shaper (CBS) to ensure that shaped traffic classes do not exceed their preconfigured bandwidth bounds. This CBS, however, only shapes the highest priorities, i.e. it introduces additional shaping delays to the most critical ones, which is undesirable for latency-sensitive traffic. Currently, a new set of Ethernet QoS mechanisms is being evaluated for standardization under the name of time-sensitive networking (TSN) [2]. One of TSN's goals is the development of new traffic shapers, which offer tight and deterministic end-to-end latencies for real-time This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement ...

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Exploring the worst-case timing of Ethernet AVB for industrial applications

Cited by 12 publications

References 11 publications

Invited - Towards fail-operational ethernet based in-vehicle networks

Invited - Towards fail-operational ethernet based in-vehicle networks

Impact Analysis of Flow Shaping in Ethernet-AVB/TSN and AFDX from Network Calculus and Simulation Perspective

Formal worst-case timing analysis of Ethernet TSN's time-aware and peristaltic shapers

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