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Fan, Xing
Publications (10 of 12) Show all publications
Fan, X., Jonsson, M. & Jonsson, J. (2009). Guaranteed real-time communication in packet-switched networks with FCFS queuing. Computer Networks, 53(3), 400-417
Open this publication in new window or tab >>Guaranteed real-time communication in packet-switched networks with FCFS queuing
2009 (English)In: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 53, no 3, p. 400-417Article in journal (Refereed) Published
Abstract [en]

In this paper, we propose a feasibility analysis of periodic hard real-time traffic in packet-switched networks using first come first served (FCFS) queuing but no traffic shapers. Our work constitutes a framework that can be adopted for real-time analysis of switched low-cost networks like Ethernet without modification of the standard network components. Our analysis is based on a flexible network and traffic model, e.g., variable-sized frames, arbitrary deadlines and multiple switches. The correctness of our real-time analysis and the tightness of it for network components in single-switch networks are given by theoretical proofs. The performance of the end-to-end real-time analysis is evaluated by simulations. Moreover, our conceptual and experimental comparison studies between our analysis and the commonly used Network Calculus (NC) shows that our analysis can achieve better performance than NC in many cases.

Place, publisher, year, edition, pages
Amsterdam: North Holland, 2009
Keywords
Real-time, Real-time communication, packet-switching, First Come First Served (FCFS)
National Category
Computer Engineering
Identifiers
urn:nbn:se:hh:diva-2316 (URN)10.1016/j.comnet.2008.10.018 (DOI)000263631500012 ()2-s2.0-58549101883 (Scopus ID)2082/2718 (Local ID)2082/2718 (Archive number)2082/2718 (OAI)
Available from: 2009-02-19 Created: 2009-02-19 Last updated: 2018-03-23Bibliographically approved
Fan, X., Jonsson, J. & Jonsson, M. (2007). Guaranteed Real-Time Communication in Packet-Switched Networks with FCFS queuing: Analysis and Simulations. Halmstad: Halmstad University
Open this publication in new window or tab >>Guaranteed Real-Time Communication in Packet-Switched Networks with FCFS queuing: Analysis and Simulations
2007 (English)Report (Other academic)
Abstract [en]

In this report, we present a real-time analytical framework and the performance evaluation on our analysis. We propose a feasibility analysis of periodic hard real-time traffic in packet-switched networks using First Come First Served (FCFS) queuing but no traffic shapers. We choose switched Ethernet as an example to present the idea of our analysis and our experimental evaluations in this report.The remainder of the report is organized as follows. In Chapter 2, we define the network models, important concepts and terminology for real-time analysis. Chapter 3 presents our real-time analysis for isolated network elements. Chapter 4 gives end-to-end real-time analysis. Chapter 5 presents the performance evaluation of our results by simulation and comparison study and summarizes this report.

Place, publisher, year, edition, pages
Halmstad: Halmstad University, 2007. p. 42
Series
Technical Report ; IDE0701
Keywords
Real-Time Communication, Packet-Switched Networks
National Category
Engineering and Technology Computer Sciences
Identifiers
urn:nbn:se:hh:diva-1989 (URN)2082/2384 (Local ID)2082/2384 (Archive number)2082/2384 (OAI)
Available from: 2008-09-29 Created: 2008-09-29 Last updated: 2018-03-23Bibliographically approved
Fan, X. & Jonsson, M. (2007). Network component architectures from a real-time perspective. Halmstad: Halmstad University
Open this publication in new window or tab >>Network component architectures from a real-time perspective
2007 (English)Report (Other academic)
Abstract [en]

In this report, we survey different architectural features of network components for packet-switched networks. Especially, we have a real-time perspective in the study. We also discuss how different architectural features vary with different implementations of two standards, RapidIO and switched Ethernet.

Place, publisher, year, edition, pages
Halmstad: Halmstad University, 2007. p. 11
Series
Research reports IDE ; IDE0777
Keywords
packet-switched networks, real-time perspective
National Category
Engineering and Technology Computer Sciences
Identifiers
urn:nbn:se:hh:diva-2147 (URN)2082/2542 (Local ID)2082/2542 (Archive number)2082/2542 (OAI)
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2018-03-23Bibliographically approved
Fan, X. (2007). Real-Time Services in Packet-Switched Networks for Embedded Applications. (Doctoral dissertation). Gothenburg: Chalmers university of technology
Open this publication in new window or tab >>Real-Time Services in Packet-Switched Networks for Embedded Applications
2007 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

Embedded applications have become more and more complex, increasing the demands on the communication network. For reasons such as safety and usability, there are real-time constraints that must be met. Also, to offer high performance, network protocols should offer efficient user services aimed at specific types of communication.

At the same time, it is desirable to design and implement embedded networks with reduced cost and development time, which means using available hardware for standard networks. To that end, there is a trend towards using switched Ethernet for embedded systems because of its hight bit rate and low cost. Unfortunately, since switched Ethernet is not specifically designed for embedded systems, it has several limitations such as poor support for QoS because of FCFS queuing policy and high protocol overhead.

This thesis contributes towards fulfilling these requirements by developing (i) real-time analytical frameworks for providing QoS guarantees in packet-switched networks and (II) packet-merging techniques to reduce the protocol overhead.

We have developed two real-time analytical frameworks for networks with FCFS queuing in the switches, one for FCFS queuing in the source nodes and one for EDF queuing in the source nodes. The correctness and tightness of the real-time analytical frameworks for different network components in a singel-switch neetwork are given by strict theoretical proofs, and the performance of our end-to-end analyses is evaluated by simulations. In conjunction with this, we have compared our results to Network Calculus (NC), a commonly used analytical scheme for FCFS queuing. Our comparison study shows that our anlysis is more accurate than NC for singel-switch networks.

To reduce the protocol overhead, we have proposed two active switched Ethernet approaches, one for real-time many-to-many communication and the other for the real-time short message traffic that is often present in embedded applications. A significant improvement in performance achieved by using our proposed active networks is demonstrated.

Although our approaches are exemplified using switched Ethernet, the general approaches are not limited to switched Ethernet networks but can easily be moified to other similar packet-switched networks.

Place, publisher, year, edition, pages
Gothenburg: Chalmers university of technology, 2007. p. 121
Series
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie, ISSN 0346-718X ; 2611
Keywords
embedded systems, real-time communication, packet-switching, swithed Ethernet, FCFS and EDF scheduling, schedulability analysis, active networking, protocol overhead
National Category
Computer Systems
Identifiers
urn:nbn:se:hh:diva-1984 (URN)2082/2379 (Local ID)978-91-7291-930-3 (ISBN)2082/2379 (Archive number)2082/2379 (OAI)
Public defence
(English)
Available from: 2008-09-29 Created: 2008-09-29 Last updated: 2018-03-23Bibliographically approved
Wang, B., Jonsson, M. & Fan, X. (2006). Analysis of Efficient TDMA Schedules via the Fat-Tree Network with Real-Time Many-to-Many Communication. In: Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks: as part of the 24th IASTED International Multi-Conference on Applied Informatics : February 14-16, 2006, Innsbruck, Austria. Paper presented at 24th IASTED International Multi-Conference on Applied Informatics, February 14-16, 2006, Innsbruck, Austria (pp. 192-197). Anaheim, CA: ACTA Press
Open this publication in new window or tab >>Analysis of Efficient TDMA Schedules via the Fat-Tree Network with Real-Time Many-to-Many Communication
2006 (English)In: Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks: as part of the 24th IASTED International Multi-Conference on Applied Informatics : February 14-16, 2006, Innsbruck, Austria, Anaheim, CA: ACTA Press, 2006, p. 192-197Conference paper, Published paper (Refereed)
Abstract [en]

The Real-Time Many-to-Many (RTM2M) communication pattern is widely used in many parallel and distributed computing applications with time constraints such as radar signal processing. In this paper, we propose how to use TDMA (Time Division Multiple Access) to achieve efficient support for RTM2M over the fat-tree network built up on 4×2 switches (four children and two parents). Moreover, we have compared four different TDMA schedules in terms of the end-to-end delay and network utilization [1] and presented two of them in detail hereby. The general formulas of the end-to-end delay of two of the most interesting schedules are derived and simulations are represented to both verify the formulas and provide support for the conclusion from the viewpoint of the network utilization.

Place, publisher, year, edition, pages
Anaheim, CA: ACTA Press, 2006
Series
Applied informatics, proceedings, ISSN 1027-2666
Keywords
Real time, Many-to-many communication, Fat-tree
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hh:diva-408 (URN)000236386800030 ()2-s2.0-34047104006 (Scopus ID)2082/732 (Local ID)0-88986-568-X (ISBN)2082/732 (Archive number)2082/732 (OAI)
Conference
24th IASTED International Multi-Conference on Applied Informatics, February 14-16, 2006, Innsbruck, Austria
Available from: 2007-01-18 Created: 2007-01-18 Last updated: 2018-03-23Bibliographically approved
Fan, X. & Jonsson, M. (2005). Admission control for switched real-time Ethernet: scheduling analysis versus network calculus. In: Proc. of the Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005. Paper presented at Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005 (pp. 4 s.).
Open this publication in new window or tab >>Admission control for switched real-time Ethernet: scheduling analysis versus network calculus
2005 (English)In: Proc. of the Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005, 2005, p. 4 s.-Conference paper, Published paper (Refereed)
Abstract [en]

Many approaches have been developed to give an estimation of the upper bound of the end-to-end delay or the response-time for real-time application, e.g., the Network Calculus (NC) model and the scheduling analysis. In this paper, we present an approach based on scheduling analysis to support guaranteed real-time services over standard switched Ethernet. Furthermore, we conduct a comparative study between these two admission control schemes, our novel algorithm and an NC-based algorithm. The simulation analysis shows that our feasibility analysis gives up to 50% higher utilization than the popular NC. Another advantage of our solution is that no additional hardware or software modification of the switch and the underlying standard. In our proposal, the traffic differentiation mechanism introduced by the IEEE 802.1D/Q standard and the standard hardware-implemented First Come First Served (FCFS) priority queuing are used in the switch and the source nodes. We have derived a feasibility analysis algorithm to ensure that the real-time requirements can be met. The algorithm also gives, as a sub-result, the needed buffer space in the end nodes and the switch. Moreover, our feasibility analysis supports variable-sized frames and switches with different bit-rates ports.

Keywords
real-time Ethernet
National Category
Computer Engineering
Identifiers
urn:nbn:se:hh:diva-2767 (URN)2082/3169 (Local ID)2082/3169 (Archive number)2082/3169 (OAI)
Conference
Swedish National Computer Networking Workshop (SNCNW’05), Halmstad, Sweden, Nov. 23-24, 2005
Available from: 2009-08-13 Created: 2009-08-13 Last updated: 2018-03-23Bibliographically approved
Fan, X. & Jonsson, M. (2005). Guaranteed real-time services over standard switched Ethernet. In: The IEEE Conference on Local Computer Networks, 30th Anniversary: proceedings, Sydney, Australia, November 15-17, 2005. Paper presented at 30th Annual IEEE Conference on Local Computer Networks (LCN'2005), Sydney, Australia, Nov. 15-17, 2005 (pp. 490-492). New York, NY: IEEE Computer Society
Open this publication in new window or tab >>Guaranteed real-time services over standard switched Ethernet
2005 (English)In: The IEEE Conference on Local Computer Networks, 30th Anniversary: proceedings, Sydney, Australia, November 15-17, 2005, New York, NY: IEEE Computer Society, 2005, p. 490-492Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we contribute with an approach to support guaranteed real-time services over standard switched Ethernet without additional hardware or software modification of the switch and the underlying standard. In our proposal, the traffic differentiation mechanism introduced by the IEEE 802.1D/Q standard and the standard hardware-implemented first come first served (FCFS) priority queuing are used in the switch and the source nodes. We have derived a feasibility analysis algorithm that can be used to ensure that the real-time requirements can be met. The algorithm also gives, as a sub-result, the needed buffer space in the end nodes and the switch. Moreover, our feasibility analysis supports variable-sized frames and switches with different bit-rates ports. The simulation analysis verifies our feasibility analysis.

Place, publisher, year, edition, pages
New York, NY: IEEE Computer Society, 2005
Series
Conference on local computer networks, ISSN 0742-1303 ; 30
Keywords
Local area networks, Queueing theory, Switching networks, Telecommunication standards, Telecommunication traffic
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hh:diva-410 (URN)10.1109/LCN.2005.73 (DOI)000235161300068 ()2-s2.0-33751435868 (Scopus ID)2082/734 (Local ID)0-7695-2421-4 (ISBN)2082/734 (Archive number)2082/734 (OAI)
Conference
30th Annual IEEE Conference on Local Computer Networks (LCN'2005), Sydney, Australia, Nov. 15-17, 2005
Note

©2005 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Available from: 2007-01-18 Created: 2007-01-18 Last updated: 2018-03-23Bibliographically approved
Fan, X., Jonsson, M. & Hoang, H. (2004). Efficient Many-to-Many Real-Time Communication Using an Intelligent Ethernet Switch. In: D.F. Hsu, K. Hiraki, S. Shen, H. Sudborough (Ed.), Proceedings of the 7th International Symposium on Parallel Architectures, Algorithms and Networks, 2004: . Paper presented at 7th International Symposium on Parallel Architectures, Algorithms and Networks, Hong Kong, China, 10-12 May, 2004 (pp. 280-287). Piscataway, N.J.: IEEE
Open this publication in new window or tab >>Efficient Many-to-Many Real-Time Communication Using an Intelligent Ethernet Switch
2004 (English)In: Proceedings of the 7th International Symposium on Parallel Architectures, Algorithms and Networks, 2004 / [ed] D.F. Hsu, K. Hiraki, S. Shen, H. Sudborough, Piscataway, N.J.: IEEE , 2004, p. 280-287Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a solution for efficient many-to-many communication over switched Ethernet. The performance of using an ordinary switch and an intelligent switch is compared, and the results of the analysis based on 100 Mbit/s fast Ethernet show that an intelligent switch used to handle many-to-many communication can give better performance (shorter latency and higher utilization) than an ordinary switch. We also extend the network to serve many-to-many traffic with real-time demands by adding a thin software layer to the intelligent Ethernet switch and the end-nodes. Earliest deadline first (EDF) scheduling is used.

Place, publisher, year, edition, pages
Piscataway, N.J.: IEEE, 2004
Series
International Symposium on Parallel Architectures, Algorithms and Networks, ISSN 1087-4089 ; 7
Keywords
Local area networks, Real-time systems, Scheduling, Telecommunication switching, Telecommunication traffic
National Category
Computer Systems
Identifiers
urn:nbn:se:hh:diva-387 (URN)10.1109/ISPAN.2004.1300493 (DOI)000222086800046 ()2-s2.0-3543078803 (Scopus ID)2082/711 (Local ID)0-7695-2135-5 (ISBN)2082/711 (Archive number)2082/711 (OAI)
Conference
7th International Symposium on Parallel Architectures, Algorithms and Networks, Hong Kong, China, 10-12 May, 2004
Note

©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Available from: 2007-01-12 Created: 2007-01-12 Last updated: 2018-03-23Bibliographically approved
Fan, X. & Jonsson, M. (2004). Efficient Support for High Traffic-Volumes of Short-Message Real-Time Communication Using an Active Ethernet Switch. In: Proceedings of the 10th International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04): . Paper presented at International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04), Göteborg, Sweden, Aug. 25-27, 2004 (pp. 517-533).
Open this publication in new window or tab >>Efficient Support for High Traffic-Volumes of Short-Message Real-Time Communication Using an Active Ethernet Switch
2004 (English)In: Proceedings of the 10th International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04), 2004, p. 517-533Conference paper, Published paper (Refereed)
Abstract [en]

There are several different types of communication traffic with real- time demands apparent in distributed industrial and embedded systems, for example, group communication and process synchronization. The length of these messages is often very short but the traffic volume might be really high. Standard network protocols do not normally reach very high utilization for such small messages. This paper presents a solution to efficiently support real-time short message communication over switched Ethernet. In our proposal, the Ethernet switch and the end-nodes are enhanced to combine several short messages into an Ethernet frame to improve the performance, and to give the short-message traffic real-time support on two levels, short-frame level and Ethernet frame level. Earliest Deadline First (EDF) scheduling is used in the switch and in the source nodes on both these two levels. We have characterized the performance of the network in terms of channel utilization and the number of accepted real-time channels, by simulations of the network assuming Fast Ethernet. We also show, by example, that we can reach an improvement of the possible short-message rate of 66%.

Keywords
Real-time, Real-time communication, Real-time systems, Ethernet switches
National Category
Computer Systems
Identifiers
urn:nbn:se:hh:diva-395 (URN)2082/719 (Local ID)2082/719 (Archive number)2082/719 (OAI)
Conference
International Conference on Real-time and Embedded Computing Systems and Applications (RTCSA’04), Göteborg, Sweden, Aug. 25-27, 2004
Available from: 2007-01-12 Created: 2007-01-12 Last updated: 2018-03-23Bibliographically approved
Fan, X. & Jonsson, M. (2004). Guaranteed Real-Time Services in Switched Ethernet Networks with Deadline Scheduling in the End Nodes. In: : . Paper presented at 2nd Swedish National Computer Networking Workshop (SNCNW'04), Karlstad University, Karlstad, Sweden, 23-24 November, 2004.
Open this publication in new window or tab >>Guaranteed Real-Time Services in Switched Ethernet Networks with Deadline Scheduling in the End Nodes
2004 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This paper proposes a switched Ethernet network that supports real-time communication with guaranteed bit rate and end-to-end delay bound. In our proposal, the source nodes use Earliest Deadline First (EDF) scheduling, while the switch uses First Come First Served (FCFS) to control periodic real-time traffic belonging to logical realtime connections. The schedulability condition is drawn and the end-to-end worst-case delay bound is derived for guaranteed real-time traffic, which also gives, as a sub-result, the needed buffer space in the switch. Moreover, different traffic classes are prioritized and put into different output queues in the end nodes and the switch, which minimizes the interference with other traffic when transmitting periodic time-critical messages. The solution requires no additional hardware or software modifications of the switch and the underlying standard. It is based purely on software implementation in the end nodes. Furthermore, the EDF scheduling strategy used in the source nodes allows good resource utilization, while the FCFS scheduling used in the switch limits the switch processing overhead. The paper presents simulation analysis for Fast Ethernet, which verifies our approach of guaranteeing real-time transmission at the same time as achieving high utilization.

Keywords
real-time Ethernet
National Category
Computer Engineering
Identifiers
urn:nbn:se:hh:diva-2751 (URN)2082/3153 (Local ID)2082/3153 (Archive number)2082/3153 (OAI)
Conference
2nd Swedish National Computer Networking Workshop (SNCNW'04), Karlstad University, Karlstad, Sweden, 23-24 November, 2004
Available from: 2009-08-12 Created: 2009-08-12 Last updated: 2018-03-23Bibliographically approved
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