Adaptive Estimation of Clock Skew and Different Types of Delay in the Internet Network
The end-to-end delay is often used to analyze network performance. There are different types of delay in the network: (artificial) delay due to unsynchronized clocks, transmission and propagation delays, and delay jitter. First, we show how to obtain a least-squares estimate of the clock skew (i.e. difference between the sender and receiver clock frequencies) and the fixed delay. We then show that the linear programming algorithm proposed elsewhere to estimate the clock ratio is equivalent to the maximum likelihood estimator if the delay jitter is modeled as an independent, identically distributed random process with an exponential probability density function. Finally, we show how to estimate the delay jitter and propose an unbiased recursive least-squares algorithm to estimate the clock skew and fixed delay.
KeywordsQuartz Microwave Eter Acoustics Estima
Unable to display preview. Download preview PDF.
- 1.O. Hodson, C. Perkins, and V. Hardman, “Skew detection and compensation for Internet audio applications,” in Proc. IEEE ICME, 2000, vol. 3, pp. 1687– 1690.Google Scholar
- 2.S. B. Moon, P. Skelly, and D. Towsley, “Estimation and removal of clock skew from network delay measurements,” in Proc. IEEE INFOCOM, 1999, vol. 1, pp. 227 - 234.Google Scholar
- 3.T. Trump, “Estimation of clock skew in telephony over packet switched networks,” in Proc. IEEE ICASSP, 2000, vol. 5, pp. 2605 - 2609.Google Scholar
- 4.P. Deleon and C. J. Sreenan, “An adaptive predictor for media playout buffering,” in Proc. IEEE ICASSP, 1999, vol. 6, pp. 3097 - 3100.Google Scholar
- 5.H. Schulzrinne and J. Rosenberg, “The IETF internet telephony architecture and protocols,” IEEE Network, vol. 13, pp. 18-23, May/June 1999.Google Scholar
- 6.S. Haykin, Adaptive Filter Theory. Fourth Edition, Prentice Hall, Upper Saddle River, N.J., 2002.Google Scholar