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Journal of Computer Networks and Communications
Volume 2013 (2013), Article ID 614157, 10 pages
http://dx.doi.org/10.1155/2013/614157
Research Article

Characteristics of Video Traffic from Videoconference Applications: From H.261 to H.264

1Multimedia Technology Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens “NTUA”, Zographou 15780, Attiki, Greece
2National Center for Scientific Research “DEMOKRITOS”, Institute of Informatics and Telecommunications, Ag. Paraskevi 15310, Attiki, Greece

Received 10 September 2012; Accepted 4 December 2012

Academic Editor: Rui Zhang

Copyright © 2013 S. Domoxoudis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper presents modelling results for H.26x video traffic generated by popular videoconference software applications. The analysis of videoconference data, that were measured during realistic point-point videoconference sessions, led us to the general conclusion that the traffic can be distinguished into two categories: unconstrained and constrained. In the unconstrained traffic, there is a direct relation between the encoder and the form of the frequency histogram of the frame-size sequence. Moreover, for this type of traffic, strong correlations between successive video frames can be found. On the other hand, where bandwidth constraints are imposed during the encoding process, the generated traffic appears to exhibit similar characteristics for all the examined encoders with the very low autocorrelation values being the most notable one. On the basis of these results, this study proposes methods to calculate the parameters of a widely adopted autoregressive model for both types of traffic.