Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System
Time-triggered Ethernet (TTE) is designed as a deterministic real-time network for mixed-critical real-time systems, such as industrial automation, aerospace, and aviation. Due to asynchrony between tasks and the network in end systems (ESes), time-triggered (TT) messages have to spend uncertain tim...
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| Format: | Article |
| Language: | English |
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IEEE
2020-01-01
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| Series: | IEEE Access |
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| Online Access: | https://ieeexplore.ieee.org/document/8974276/ |
| _version_ | 1818664568741691392 |
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| author | Jun Lu Huagang Xiong Feng He Rongwei Wang |
| author_facet | Jun Lu Huagang Xiong Feng He Rongwei Wang |
| author_sort | Jun Lu |
| collection | DOAJ |
| description | Time-triggered Ethernet (TTE) is designed as a deterministic real-time network for mixed-critical real-time systems, such as industrial automation, aerospace, and aviation. Due to asynchrony between tasks and the network in end systems (ESes), time-triggered (TT) messages have to spend uncertain time in waiting for being scheduled after they are generated. The waiting time uncertainly increases end to end delays for TT messages and will degrade the real-time and determinacy of TT messages sequentially. The contribution of this paper is to present a new architecture SDTTE to minimize the end to end delays, so as to enhance real-time and determinacy of TT messages. More specifically, a frame-based network model is built to describe distributed network resources. Under the network model, the end to end delay model with asynchrony between tasks and the network is analyzed. To match the generated time with the triggered time for TT messages, the triggered mechanism of the TT traffic in ESes is regarded as event strategy to detect the generated time of TT messages automatically. Based on this, the software defined TTE (SDTTE) is presented to optimize TT schedule online in switches. Furthermore, a simplified algorithm based on Satisfiability Modulo Theories (SMT) is proposed to satisfy real-time computing requirements. Finally, experiments with three network sizes verify the availability of SDTTE and analyze its performance. The results show that end to end delays for TT messages in SDTTE are decreased by about 95% compared with those in TTE. And the delays for rate-constrained and best-effort messages in SDTTE are almost as well as those in TTE. The processing time is less than 10s. In general, SDTTE provides a method to optimize end to end delays for TT messages in TTE, thus SDTTE has more determinacy and real-time than TTE. Meanwhile, SDTTE makes dynamic reconfiguration possible in practice. |
| first_indexed | 2024-12-17T05:34:49Z |
| format | Article |
| id | doaj.art-bb20c03e178842a1ae60bc1c73645f59 |
| institution | Directory Open Access Journal |
| issn | 2169-3536 |
| language | English |
| last_indexed | 2024-12-17T05:34:49Z |
| publishDate | 2020-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Access |
| spelling | doaj.art-bb20c03e178842a1ae60bc1c73645f592022-12-21T22:01:39ZengIEEEIEEE Access2169-35362020-01-018237202373110.1109/ACCESS.2020.29702668974276Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical SystemJun Lu0https://orcid.org/0000-0003-2086-0158Huagang Xiong1https://orcid.org/0000-0002-9980-5161Feng He2https://orcid.org/0000-0001-5128-3061Rongwei Wang3https://orcid.org/0000-0002-9895-4122School of Electronic and Information Engineering, Beihang University, Beijing, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing, ChinaTime-triggered Ethernet (TTE) is designed as a deterministic real-time network for mixed-critical real-time systems, such as industrial automation, aerospace, and aviation. Due to asynchrony between tasks and the network in end systems (ESes), time-triggered (TT) messages have to spend uncertain time in waiting for being scheduled after they are generated. The waiting time uncertainly increases end to end delays for TT messages and will degrade the real-time and determinacy of TT messages sequentially. The contribution of this paper is to present a new architecture SDTTE to minimize the end to end delays, so as to enhance real-time and determinacy of TT messages. More specifically, a frame-based network model is built to describe distributed network resources. Under the network model, the end to end delay model with asynchrony between tasks and the network is analyzed. To match the generated time with the triggered time for TT messages, the triggered mechanism of the TT traffic in ESes is regarded as event strategy to detect the generated time of TT messages automatically. Based on this, the software defined TTE (SDTTE) is presented to optimize TT schedule online in switches. Furthermore, a simplified algorithm based on Satisfiability Modulo Theories (SMT) is proposed to satisfy real-time computing requirements. Finally, experiments with three network sizes verify the availability of SDTTE and analyze its performance. The results show that end to end delays for TT messages in SDTTE are decreased by about 95% compared with those in TTE. And the delays for rate-constrained and best-effort messages in SDTTE are almost as well as those in TTE. The processing time is less than 10s. In general, SDTTE provides a method to optimize end to end delays for TT messages in TTE, thus SDTTE has more determinacy and real-time than TTE. Meanwhile, SDTTE makes dynamic reconfiguration possible in practice.https://ieeexplore.ieee.org/document/8974276/End to end delaydeterminacyreal-timesoftware defined networktime-triggered ethernet |
| spellingShingle | Jun Lu Huagang Xiong Feng He Rongwei Wang Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System IEEE Access End to end delay determinacy real-time software defined network time-triggered ethernet |
| title | Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System |
| title_full | Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System |
| title_fullStr | Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System |
| title_full_unstemmed | Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System |
| title_short | Enhancing Real-Time and Determinacy for Network-Level Schedule in Distributed Mixed-Critical System |
| title_sort | enhancing real time and determinacy for network level schedule in distributed mixed critical system |
| topic | End to end delay determinacy real-time software defined network time-triggered ethernet |
| url | https://ieeexplore.ieee.org/document/8974276/ |
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