Timeliness of real-time IP communication in switched industrial Ethernet networks

Through several giant evolutionary steps, Ethernet has become an almost ubiquitous technology for communication. Being versatile enough to be employed in new and various fields of application, it is now making inroads in factories. However, automated systems are different from many other applications of Ethernet,first and foremost because they require the network technology to deliver real-time performance. In the present study, a number of critical aspects of Ethernet, usually referred to as an Industrial Ethernet, are examined. More specifically, there is a focus on the application-to-application delay and jitter characteristics of such networks, when using Internet protocols such as UDP and TCP. It is demonstrated how important it is to take control of the latency in the station nodes, since the main communication delays occur inside the nodes, and different solutions are presented for controlling these delays. In particular, a priority-based protocol stack is assessed. The results show that real-time, Ethernet-based IP communication is now adequate even for demanding automated applications. In this paper, substation automation (power distribution) is used as an example of a demanding automation system.

[1]  Hermann Härtig,et al.  Low-latency hard real-time communication over switched Ethernet , 2004, Proceedings. 16th Euromicro Conference on Real-Time Systems, 2004. ECRTS 2004..

[2]  Adam Dunkels,et al.  Full TCP/IP for 8-bit architectures , 2003, MobiSys '03.

[3]  T. Skeie,et al.  The road to an end-to-end deterministic Ethernet , 2002, 4th IEEE International Workshop on Factory Communication Systems.

[4]  Rene L. Cruz,et al.  A calculus for network delay, Part II: Network analysis , 1991, IEEE Trans. Inf. Theory.

[5]  Hoai Hoang,et al.  Switched real-time Ethernet in industrial applications - deadline partitioning , 2003, 9th Asia-Pacific Conference on Communications (IEEE Cat. No.03EX732).

[6]  I. Nikolaidis The switch book: the complete guide to LAN switching technology [Book Review] , 2000, IEEE Network.

[7]  Anis Koubaa,et al.  Switched Ethernet for real-time industrial communication: modelling and message buffering delay evaluation , 2002, 4th IEEE International Workshop on Factory Communication Systems.

[8]  Marzuki Khalid,et al.  Tuning of a neuro-fuzzy controller by genetic algorithm , 1999, IEEE Trans. Syst. Man Cybern. Part B.

[9]  Jean-Yves Le Boudec,et al.  Network Calculus , 2001, Lecture Notes in Computer Science.

[10]  J. Loeser,et al.  Low-latency hard real-time communication over switched Ethernet , 2004 .

[11]  T. Skeie,et al.  Ethernet in substation automation , 2002 .

[12]  Lucia Lo Bello,et al.  Improving the real-time behavior of ethernet networks using traffic smoothing , 2005, IEEE Transactions on Industrial Informatics.

[13]  Kang G. Shin,et al.  Achieving real-time communication over Ethernet with adaptive traffic smoothing , 2000, Proceedings Sixth IEEE Real-Time Technology and Applications Symposium. RTAS 2000.

[14]  Peter Neumann,et al.  Deterministic real-time communication with switched Ethernet , 2002, 4th IEEE International Workshop on Factory Communication Systems.

[15]  Rich Seifert,et al.  The Switch Book: The Complete Guide to LAN Switching Technology , 2000 .

[16]  Sudhakar Yalamanchili,et al.  Interconnection Networks: An Engineering Approach , 2002 .

[17]  Baek-Young Choi,et al.  Probabilistic approach to switched Ethernet for real-time control applications , 2000, Proceedings Seventh International Conference on Real-Time Computing Systems and Applications.

[18]  Eric Rondeau,et al.  How to be sure that switched Ethernet networks satisfy the real-time requirements of an industrial application? , 2002, Industrial Electronics, 2002. ISIE 2002. Proceedings of the 2002 IEEE International Symposium on.

[19]  Charles L. Seitz,et al.  Myrinet: A Gigabit-per-Second Local , 1995 .

[20]  L. Lo Bello,et al.  Performances analysis of Ethernet networks in the process control , 2000, ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543).

[21]  Jonas Berge,et al.  FOUNDATION^^ Fieldbus High Speed Ethemet , 2002 .

[22]  Magnus Jonsson,et al.  Efficient many-to-many real-time communication using an intelligent Ethernet switch , 2004, 7th International Symposium on Parallel Architectures, Algorithms and Networks, 2004. Proceedings..

[23]  Mathai Joseph,et al.  Finding Response Times in a Real-Time System , 1986, Comput. J..

[24]  Edward W. Knightly,et al.  Egress admission control , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[25]  E. Douglas Jensen Asynchronous Decentralized Real-Time Computer Systems , 2000 .

[26]  Charles L. Seitz,et al.  Myrinet: A Gigabit-per-Second Local Area Network , 1995, IEEE Micro.

[27]  Rene L. Cruz,et al.  A calculus for network delay, Part I: Network elements in isolation , 1991, IEEE Trans. Inf. Theory.

[28]  Jürgen Jasperneite,et al.  Switched Ethernet for factory communication , 2001, ETFA 2001. 8th International Conference on Emerging Technologies and Factory Automation. Proceedings (Cat. No.01TH8597).

[29]  Paul Innella Asynchronous Transfer Mode , 2001 .

[30]  Binoy Ravindran,et al.  Time-utility function-driven switched Ethernet: packet scheduling algorithm, implementation, and feasibility analysis , 2004, IEEE Transactions on Parallel and Distributed Systems.

[31]  James W. Layland,et al.  Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment , 1989, JACM.

[32]  Suk Lee,et al.  Performance evaluation of switched Ethernet for networked control systems , 2002, IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02.

[33]  A. Koubaa,et al.  Evaluation and improvement of response time bounds for real-time applications under non-pre-emptive Fixed Priority Scheduling , 2004 .

[34]  Scott Shenker,et al.  Endpoint admission control: architectural issues and performance , 2000, SIGCOMM.

[35]  Paulo Pedreiras,et al.  Characterizing the Real-Time Behavior of Prioritized Switched-Ethernet 1 , 2003 .

[36]  Olav Lysne,et al.  Achieving Flow Level QoS in Cut-Through Networks Through Admission Control and DiffServ , 2004, PDPTA.

[37]  Z. Hanzalek,et al.  Simulation of Ethernet for real-time applications , 2003, IEEE International Conference on Industrial Technology, 2003.

[38]  Wilton R. Abbott,et al.  Network Calculus , 1970 .

[39]  Eric Rondeau,et al.  Evaluation of switched Ethernet in an industrial context by using the Network Calculus , 2002, 4th IEEE International Workshop on Factory Communication Systems.

[40]  Ray Jain,et al.  The art of computer systems performance analysis - techniques for experimental design, measurement, simulation, and modeling , 1991, Wiley professional computing.

[41]  Olav Lysne,et al.  Admission Control for DiffServ Based Quality of Service in Cut-Through Networks , 2003, HiPC.

[42]  Chung Laung Liu,et al.  Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment , 1989, JACM.

[43]  John P. Lehoczky,et al.  Fixed priority scheduling of periodic task sets with arbitrary deadlines , 1990, [1990] Proceedings 11th Real-Time Systems Symposium.