Requirements Engineering

, Volume 9, Issue 2, pp 121–131 | Cite as

Acquiring and incorporating state-dependent timing requirements

Original Article

Abstract

Some real-time systems are designed to deliver services to objects that are controlled by external sources. Their services must be delivered on a timely basis, and the system fails when some services are delivered too late. In general, the timing requirements of the system may change when the states of the objects monitored by the system change. Such a system may fail if the timing requirements which it is designed to meet are erroneous. It may underutilize resources and consequently be costly or unreliable if the requirements are too stringent. Hence, one must identify how changes in object states call for changes in system requirements and how these changes should be incorporated into the design and implementation of the system. This paper first describes a methodology to determine timing requirements and to take into account requirement changes at runtime. The method is based on several timing requirement determination schemes. Simulation data show that these schemes are effective for applications such as mobile IP hand-offs. The paper then discusses how to incorporate this methodology in the system architecture and in the development process.

Keywords

Real-time requirements Requirement capture and update Real-time software architecture 

Notes

Acknowledgements

This work is supported in part by a grant from the MURI program N00014-01-0576, in part by ONR N0004-02-0102, and in part by Lockheed Martin Corporation 1-5-36137.

References

  1. 1.
    Buttazzo G, Lipari G, Abeni L (1998) Elastic task model for adaptive rate control. In: Proceedings of the IEEE real-time systems symposium, Dec 1998, pp 286–295Google Scholar
  2. 2.
    Liu CL, Layland J (1973) Scheduling algorithms for multiprogramming in a hard real-time environment. J ACM 20:46–61CrossRefGoogle Scholar
  3. 3.
    Han C, Lin K (1992) Scheduling distance-constrained real-time tasks. In: Proceedings of the IEEE real-time systems symposium, Dec 1992, pp 300–308Google Scholar
  4. 4.
    Sprunt B, Sha L, Lehoczky J (1989) Aperiodic task scheduling for hard-real-time systems. Real-time Syst J 1:27–60Google Scholar
  5. 5.
    Liu JWS, Shih WK, Lin KJ, Bettati R, Chung JY (1994) Imprecise computations. Proc IEEE 82:83–94CrossRefGoogle Scholar
  6. 6.
    Tai TS, Deng Z, Shankarand M, Storch M, Sun J, Wu LC, Liu JWS (1995) Probabilistic performance guarantee for real-time tasks with varying computation times. In: Proceedings of the IEEE real-time technology and application symposium, 1995, pp 164–173Google Scholar
  7. 7.
    Shih CS, Liu JWS (2002) State-dependent deadline scheduling. In: Proceedings of the IEEE real-time systems symposium, Austin, TX, USA, 2002, pp 3–14Google Scholar
  8. 8.
    Stankovic JA, Lu C, Son SH, Tao G (1999) The case for feedback control real-time scheduling. In: Proceedings of the 11th Euromicro conference on real-time systems, 1999, pp 11–20Google Scholar
  9. 9.
    Caccamo M, Buttazzo G, Sha L (2000) Elastic feedback control. In: Proceedings of the 12th Euromicro conference on real-time systems, 2000, pp 121–128Google Scholar
  10. 10.
    Caccamo M, Buttazzo G, Sha L (2000) Capacity sharing for overrun control. In: Proceedings of the IEEE real-time systems symposium, Orlando, FL, USA, 2000, pp 295–304Google Scholar
  11. 11.
    Abeni L, Butazzo G (1999) QoS guarantee using probabilistic deadlines. In: Proceeding of the 11th Euromicro conference on real-time systems (ECRTS99), York, England, 1999, pp 242–251Google Scholar
  12. 12.
    Martin RC (2002) Agile software development, principles, patterns, and practices. Prentice Hall, Upper Saddle River, NJGoogle Scholar
  13. 13.
    Lutz RR, Mikulski IC (2003) Resolving requirements discovery in testing and operations. In: Proceedings of the 11th IEEE international requirements engineering conference (RE’03), 2003, Monterey Bay, CA, USA, , pp 33–41Google Scholar
  14. 14.
    Dubois E, Pohl K (2003) RE 02: A major step toward a mature requirements engineering community. IEEE Software 20:14–15CrossRefGoogle Scholar
  15. 15.
    Perkins CE, Wang KY (1999) Optimized smooth handoffs in Mobile IP. In: Proceedings of the IEEE international symposium on computers and communications, July 1999, pp 340–346Google Scholar
  16. 16.
    Lee KD, Kim S (1999) Traffic model and analysis for handoff performance in microcellular networks with directed retry. In: Proceedings of the IEEE TENCON’99, vol 1, 1999, pp 39–42Google Scholar
  17. 17.
    Ghazalie TM, Baker TP (1995) Aperiodic servers in a deadline scheduling environment. Real-Time Syst J 9:31--67Google Scholar

Copyright information

© Springer-Verlag London Limited 2004

Authors and Affiliations

  1. 1.Department of Computer ScienceUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  2. 2.Microsoft CorporationRedmondUSA

Personalised recommendations