Deterministic delay analysis of AVB switched Ethernet networks using an extended Trajectory Approach

Li, Xiaoting; George, Laurent

doi:10.1007/s11241-016-9260-5

Cited by 21 publications

(12 citation statements)

References 31 publications

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“…A first solution to overcome these issues is to use traffic shaping policies, this is what is done in AVB with the Credit-Based Shaper (CBS) defined in IEEE 801.Qav. The reader can consult [1,5] and [6] for an analysis of the CBS mechanisms.…”

Section: Quality Of Service Protocols For Ethernetmentioning

confidence: 99%

Pre-Shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

Navet¹,

Migge²,

Villanueva³

et al. 2018

SAE Int. J. Passeng. Cars – Electron. Electr. Syst.

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The automotive industry is swiftly moving towards Ethernet as the high-speed communication network for in-vehicle communication. There is nonetheless a need for protocols that go beyond what standard Ethernet has to offer in order to provide additional QoS to demanding applications such as ADAS systems or audio/video streaming. The main protocols currently considered for that purpose are IEEE802.1Q, AVB with the Credit Based Shaper mechanism (IEEE802.1Qav) and TSN with its Time-Aware Shaper (IEEE802.1Qbv). AVB/CBS and TSN/TAS both provide efficient QoS mechanisms and they can be used in a combined manner, which offers many possibilities to the designer. Their use however requires dedicated hardware and software components, and clock synchronization in the case of TAS. Previous studies have also shown that the efficiency of these protocols depends much on the application at hand and the value of the configuration parameters. In this work, we explore the use of "pre-shaping" strategies under IEEE802.1Q for bursty traffic such as audio/video streams as a simple and efficient alternative to AVB/CBS and TSN/TAS. Pre-shaping means inserting on the sender side "well-chosen" pauses between successive frames of a burst (e.g., a camera frame), all the other characteristics of traffic remaining unchanged. We show on an automotive case-study how the use of pre-shaping for audio/video streams leads to a drastic reduction of the communication latencies for the best-effort streams while enabling to meet the timing constraints for the rest of the traffic. We then discuss the limitations of the pre-shaping mechanism and future works needed to facilitate its adoption.

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Section: Quality Of Service Protocols For Ethernetmentioning

confidence: 99%

Pre-Shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

Navet¹,

Migge²,

Villanueva³

et al. 2018

SAE Int. J. Passeng. Cars – Electron. Electr. Syst.

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“…Previous studies of Ethernet AVB can be found in e.g. Imtiaz et al (2009), Diemer et al (2012a), Diemer et al (2012b), Reimann et al (2013), Bordoloi et al (2014), Axer et al (2014), Ashjaei et al (2017) and Li and George (2017). In Imtiaz et al (2009), a single-hop timing analysis of Ethernet AVB is presented for a scenario in which a single frame is interfered by both high-and low-priority traffic, but no formal study is executed to prove that the resulting formulas match the worst-case in all possible scenarios.…”

Section: Related Workmentioning

confidence: 99%

“…The improvement done by Bordoloi et al (2014) is not considered in Ashjaei et al (2017), as the improved solution is too complicated to determine the network bandwidth reservation. Li and George (2017) present a schedulability analysis to compute the worst-case delay of messages from classes A and B using the trajectory approach (Martin and Minet 2006) in a multi-hop network. This work partially uses busy period analysis to limit the search space of time within which the worst-case delay upper bound can be found and it provides a tighter analysis compared to Diemer et al (2012b).…”

Section: Related Workmentioning

confidence: 99%

“…Besides the pessimism, another disadvantage of using busy period analysis is that a detailed traffic model is required, e.g., a periodic/sporadic model in Bordoloi et al (2014) and Li and George (2017) or arrival curves in Diemer et al (2012b) and Axer et al (2014). The dependence on a detailed traffic model makes the timing analysis quite complicated in terms of algorithmic complexity, and meanwhile not robust against traffic flow changes.…”

Section: Related Workmentioning

confidence: 99%

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Independent WCRT analysis for individual priority classes in Ethernet AVB

et al. 2018

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In the high-tech and automotive industry, bandwidth considerations and widely accepted standardization are two important reasons why Ethernet is currently being considered as an alternative solution for real-time communication (compared to traditional fieldbusses). Although Ethernet was originally not intended for this purpose, the development of the Ethernet AVB standard enables its use for transporting high-volume data (e.g. from cameras and entertainment applications) with low-latency guarantees. In complex industrial systems, the network is shared by many applications, developed by different parties. To face this complexity, the development of these applications must be kept as independent as possible. In particular, from a network point of view, progress of all communication streams must be guaranteed, and the performance for individual streams should be predictable using only information regarding the stream under study and the general parameters of the communication standard used by the network. Initial methods to guarantee latency for Ethernet AVB networks rely on the traditional busy-period analysis. Typically, these methods are based on knowledge of the inter-arrival patterns of both the stream under study and the interfering streams that also traverse the network. The desired independence is therefore not achieved. In this paper, we present an independent real-time analysis based on so-called eligible intervals, which does not rely on any assumptions on interfering priority classes other than those enforced in the Ethernet AVB standard. We prove this analysis is tight in case there is only a single higher-priority stream, and no additional information on interference is known. In case there are multiple higher-priority streams, we give conditions under which the analysis is still tight. Furthermore, we compare the results of our approach to the two most recent busy-period analyses, point out sources of pessimism in these earlier works, and argue that assuming more information on the sources of interference (e.g. a minimal inter-arrival time between interfering frames) has only limited advantages.

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“…is assumption is not necessarily true in all switch as frames get serialized from one switch to the other resulting in less blocking and smaller end-to-end delay with respect to what a local analysis can compute. To eliminate this pessimism an end-toend analysis needs to be proposed, for example a solution based on the trajectory approach [10]. is is one of our future objectives.…”

Section: Default Experimentsmentioning

confidence: 99%

Delay analysis of AVB traffic in time-sensitive networks (TSN)

Maxim

Song

2017

Proceedings of the 25th International Conference on Real-Time Networks and Systems

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Future autonomous vehicles and ADAS (Advanced Driver Assistance Systems) need real-time audio and video transmission together with control data tra c (CDT). Audio/video stream delay analysis has been largely investigated in AVB (Audio Video Bridging) context, but not yet with the presence of the CDT in the new TSN context. In this paper we present a local delay analysis of AVB frames under hierarchical scheduling of credit-based shaping and time-aware shaping on TSN switches. We present the e ects of time aware shaping on AVB tra c, how it changes the relative order of transmission of frames leading to bursts and worst case scenarios for lower priority streams. We also show that these bursts are upper-bounded by the Credit-Bases Shaper, hence the worst-case transmissions delay of a given stream is also upper-bounded. We present the analysis to compute the worst case delay for a frame, as well as the feasibility condition necessary for the analysis to be applied. Our methods (analysis and simulation) are applied to an automotive use case, which is de ned within the Eurostars RETINA project, and where both control data tra c and AVB tra c must be guaranteed. CCS CONCEPTS •Computer systems organization →Embedded systems; •Networks →Network reliability;

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Deterministic delay analysis of AVB switched Ethernet networks using an extended Trajectory Approach

Cited by 21 publications

References 31 publications

Pre-Shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

Pre-Shaping Bursty Transmissions under IEEE802.1Q as a Simple and Efficient QoS Mechanism

Independent WCRT analysis for individual priority classes in Ethernet AVB

Delay analysis of AVB traffic in time-sensitive networks (TSN)

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