IE interfaces (산업공학)

Korean Institute of Industrial Engineers (대한산업공학회)
권호 표지

Robust Design Methodology for Optimizing Perceived QoS of VoIP

인터넷 전화의 사용자 관점 품질 최적화를 위한 강건 설계 기법 연구

  • 윤협상 (KT 중앙연구소) ;
  • 최수현 (런던대학교 컴퓨터과학과) ;
  • 김성준 (노스캐롤라이나주립대학교 컴퓨터과학과)
  • Received : 2008.07.02
  • Accepted : 2009.01.23
  • Published : 2009.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

During the past few years, design of experiments (DOE) has been gaining acceptance in the telecommunications research community as a mean for designing and analyzing experiments economically and efficiently. In addition, the need for introducing a systematic robust design methodology (i.e., one of the most popular DOE methodologies) to network simulations has been increasing. In this paper, we present an architecture of voice over IP (VoIP) application and the E-Model for calculating the perceived quality of service (QoS). Then, we apply the Taguchi robust design methodology to optimize the perceived QoS of VoIP application, and describe the detailed step-by-step procedures. We have used ns-2 simulator to collect experimental data in which the SN ratio, a robustness measure, is analyzed to determine an optimal design condition. The analysis shows that "initial delay time in playout buffer" is a major control factor for ensuring robust behaviors of the perceived QoS of VoIP. Finally, we verify the proposed optimal design condition using a confirmation experiment.

Keywords

References

  1. Atzori, L. and Lobina,M. L. (2006), Playout buffering in IP telephony : a survey discussing problems and approaches, IEEE Communication Surveys Tutorial, 8(3), 36-46 https://doi.org/10.1109/COMST.2006.253269
  2. Bacioccola, C., Cicconetti, C., and Stea, C. (2007), User-level performance evaluation of VoIP using ns-2, Proceedings of Workshop on Network Simulation Tools 2007, Nantes, France
  3. Blake, S., Black, D., Carlson, M., and Davies, E. (1998), An architecture fordifferentiated services. IETF RFC 2475
  4. Cole, R. G. and Rosenbluth, J.H. (2001), Voice over IP performancemonitoring, ACM CCR, 31(2), 9-24 https://doi.org/10.1145/505666.505669
  5. Gendy,M. E., Bose, A.,Wang, H., and Shin, K. G. (2003), Statistical characterization for per-hop QoS. Proceedings of International Workshop on Quality of Service, 21-40
  6. Heidemann, J. andMills, K. (2001), Expanding confidence in network simulations,IEEE Network, 15(5), 58-63 https://doi.org/10.1109/65.953234
  7. ITU-T Recommendation G.107. (2005), The E-model, a computational model for use in transmission planning
  8. Liao, W. (1999), Mobile Internet telephony protocol : an application layer protocol for mobile Internet telephony services, Proceedings of IEEE International Conference on Communications ICC ’99, 1, 339-343
  9. Montgomery, D. C. (2005), Design and Analysis of Experiments, 6th ed., Wiley : New York, NY
  10. Myers, R. H. andMontgomery, D. C. (1995), Response SurfaceMethodology : Process and Product Optimization Using Designed Experiments, Wiley-Interscience : New York, NY
  11. Myers, R. H., Khuri, A. I., and Vining, G. (1992), Response surface alternatives to the Taguchi parameter design approach, The American Statistician, 46(2), 131-139 https://doi.org/10.2307/2684183
  12. NS-2. (2008), http://nsnam.isi.edu/nsnam/index.php/Main_Page
  13. Phadke, M. S. (1989), Quality Engineering Using Robust Design, Prentice Hall : Englewood Cliffs, NJ
  14. Taguchi, G. (1986), Introduction to Quality Engineering, Asia Productivity Organization : Tokyo
  15. Taguchi, G. and Konishi, S. (1959), Design of Experiments Using Orthogonal Tables, Union of Japanese Scientists and Engineers : Tokyo, Japan
  16. Taguchi, G. and Konishi, S. (1992), Taguchi Methods : Research and Development, ASI Press : Dearborn, MI
  17. Taguchi, G. and Yokoyama, Y. (1993), Taguchi Methods : Design of Experiments, ASI Press : Dearborn, MI
  18. Yoon, H. S. and Yum, B. J. (2007), Robust design of communication systems : The case of expedited forwarding of voice traffic in differentiated services networks, International Journal of Communication Systems, 20, 1131-1154 https://doi.org/10.1002/dac.866
  19. Ziviani, A., Rezende, J. F., and Duarte,O. C.M. B. (2002), Evaluating the expedited forwarding of voice traffic in a differentiated services network, International Journal of Communication Systems, 15, 799-813 https://doi.org/10.1002/dac.564