| 1. |
- Ashjaei, Seyed Mohammad Hossein, 1980-, et al.
(author)
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Modeling and Timing Analysis of Vehicle Functions Distributed over Switched Ethernet
- 2017
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In: IECON 2017 - 43RD ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY. - 9781538611272 ; , s. 8419-8424
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Conference paper (peer-reviewed)abstract
- This paper proposes an approach to model switched Ethernet communication within a model- and component-based software development framework for vehicular distributed embedded systems. The paper also presents a method to extract the network timing model from the systems that use switched Ethernet networks. In order to provide a proof of concept, an existing industrial component model and its tool suite, namely RCM and Rubus-ICE respectively, are extended by implementing the modeling technique, the timing model extraction method and response-time analysis of the Ethernet AVB protocol. The extensions to RCM are backward compatible with the modeling and end-to-end timing analysis of traditional in-vehicle networks and legacy (previously developed) vehicular distributed embedded systems. Furthermore, the paper discusses the implementation and test strategy used in this work. Finally, the usability of the modeling approach and implemented timing analysis is demonstrated by modeling and time analyzing a vehicular application case study with the extended component model and tool suite.
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| 2. |
- Bujosa Mateu, Daniel, et al.
(author)
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Clock Synchronization in Integrated TSN-EtherCAT Networks
- 2020
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In: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728189567 ; , s. 214-221
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Conference paper (peer-reviewed)abstract
- Moving towards new technologies, such as Time Sensitive Networking (TSN), in industries should be gradual with a proper integration process instead of replacing the existing ones to make it beneficial in terms of cost and performance. Within this context, this paper identifies the challenges of integrating a legacy EtherCAT network, as a commonly used technology in the automation domain, into a TSN network. We show that clock synchronization plays an essential role when it comes to EtherCAT-TSN network integration with important requirements. We propose a clock synchronization mechanism based on the TSN standards to obtain a precise synchronization among EtherCAT nodes, resulting to an efficient data transmission. Based on a formal verification framework using UPPAAL tool we show that the integrated EtherCAT-TSN network with the proposed clock synchronization mechanism achieves at least 3 times higher synchronization precision compared to not using any synchronization.
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| 3. |
- Bujosa Mateu, Daniel, et al.
(author)
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HERMES : Heuristic Multi-queue Scheduler for TSN Time-Triggered Traffic with Zero Reception Jitter Capabilities
- 2022
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In: ACM International Conference Proceeding Series. - New York, NY, USA : Association for Computing Machinery. - 9781450396509 ; , s. 70-80
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Conference paper (peer-reviewed)abstract
- The Time-Sensitive Networking (TSN) standards provide a toolbox of features to be utilized in various application domains.The core TSN features include deterministic zero-jitter and low-latency data transmission and transmitting traffic with various levels of time-criticality on the same network. To achieve a deterministic transmission, the TSN standards define a time-aware shaper that coordinates transmission of Time-Triggered (TT) traffic. In this paper, we tackle the challenge of scheduling the TT traffic and we propose a heuristic algorithm, called HERMES. Unlike the existing scheduling solutions, HERMES results in a significantly faster algorithm run-time and a high number of schedulable networks. HERMES can be configured in two modes of zero or relaxed reception jitter while using multiple TT queues to improve the schedulability. We compare HERMES with a constraint programming (CP)-based solution and we show that HERMES performs better than the CP-based solution if multiple TT queues are used, both with respect to algorithm run-time and schedulability of the networks.
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| 4. |
- Bujosa Mateu, Daniel, et al.
(author)
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Introducing Guard Frames to Ensure Schedulability of All TSN Traffic Classes
- 2023
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In: IEEE Int. Conf. Emerging Technol. Factory Autom., ETFA. - : Institute of Electrical and Electronics Engineers Inc.. - 9798350339918
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Conference paper (peer-reviewed)abstract
- Offline scheduling of Scheduled Traffic (ST) in Time-Sensitive Networks (TSN) without taking into account the quality of service of non-ST traffic, e.g., time-sensitive traffic such as Audio-Video Bridging (AVB) traffic, can potentially cause deadline misses for non-ST traffic. In this paper, we report our ongoing work to propose a solution that, regardless of the ST scheduling algorithm being used, can ensure meeting timing requirements for non-ST traffic. To do this, we define a frame called Guard Frame (GF) that will be scheduled together with all ST frames. We show that a proper design for the GFs will leave necessary porosity in the ST schedules to ensure that all non-ST traffic will meet their timing requirements.
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| 5. |
- Bujosa Mateu, Daniel, et al.
(author)
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LETRA : Mapping Legacy Ethernet-Based Traffic into TSN Traffic Classes
- 2021
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In: 26th IEEE International Conference on Emerging Technologies and Factory Automation ETFA 2021. - Västerås, Sweden : IEEE. - 9781728129891
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Conference paper (peer-reviewed)abstract
- This paper proposes a method to efficiently map the legacy Ethernet-based traffic into Time Sensitive Networking (TSN) traffic classes considering different traffic characteristics. Traffic mapping is one of the essential steps for industries to gradually move towards TSN, which in turn significantly mitigates the management complexity of industrial communication systems. In this paper, we first identify the legacy Ethernet traffic characteristics and properties. Based on the legacy traffic characteristics we presented a mapping methodology to map them into different TSN traffic classes. We implemented the mapping method as a tool, named Legacy Ethernet-based Traffic Mapping Tool or LETRA, together with a TSN traffic scheduling and performed a set of evaluations on different synthetic networks. The results show that the proposed mapping method obtains up to 90% improvement in the schedulability ratio of the traffic compared to an intuitive mapping method on a multi-switch network architecture.
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| 6. |
- Bujosa Mateu, Daniel, et al.
(author)
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The Effects of Clock Synchronization in TSN Networks with Legacy End-Stations
- 2022
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Conference paper (peer-reviewed)abstract
- In this paper, we present our ongoing work on proposing solutions to integrate legacy end-stations into Time-Sensitive Network (TSN) communication systems where the legacy end-stations are synchronized via their legacy clock synchronization protocol. To this end, we experimentally identify the effects of lacking synchronization or partial synchronization in TSN networks. In the experiments we show the effects of clock synchronization in different scenarios on jitter and clock drifts. Based on the experiments, we propose preliminary solutions to overcome the identified effects.
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| 7. |
- Danielsson, Jakob, et al.
(author)
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Performance Evaluation of Network Convergence Time Measurement Techniques
- 2017
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In: International Conference on Emerging Technologies And Factory Automation ETFA'17. - 9781509065059 ; , s. 1-7
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Conference paper (peer-reviewed)abstract
- In this paper we evaluate solutions that provide measurements for the network convergence time in switched Ethernet networks when links failures happen. We evaluate three solutions to measure the network convergence time in a faulty situation. Compared to the commercially available solutions, our proposals are cost-effective, portable, and open source. Thus, they are easy to deploy on many testbeds. We show the performance of the solutions by measuring different metrics including jitter, network convergence time and packet loss during the network recovery time. Our measurements indicate that it is possible to accurately measure the network convergence time using a packet sender which does not suffer interference from the overlying operating system. Furthermore, we noticed that the packet sniffer TShark did not suffer from kernel interrupts from overlying operating systems.
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| 8. |
- Hallmans, Daniel, et al.
(author)
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Analysis of the TSN Standards for Utilization in Long-life Industrial Distributed Control Systems
- 2020
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In: The 25th International Conference on Emerging Technologies and Factory Automation ETFA2020. - Vienna, Austria.
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Conference paper (peer-reviewed)abstract
- Large complex industrial Distributed Control Systems (DCS), e.g., power distribution systems, are expected to function for long time, up to 40 years. Therefore, besides having a long system verification phase for all subsystems, the design phase should consider various aspects when it comes to selection of which technologies to utilize when implementing such systems. In this paper, we study and investigate key challenges of using the Time Sensitive Networking (TSN) technology when it comes to design, maintenance and evolution of long life-span complex DCS. We also identify issues and challenges, and propose mitigation strategies for using the TSN technology in long-life system design. Our investigation and analysis shows that many of the TSN standards are in their evolution phase and may as a consequence be subject to different interpretations and implementations. Therefore, achieving a full capacity of using the TSN technology may not be possible, in particular when it comes to design of systems having an expected long life.
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