High-Assurance Video Conference System over the Internet

Masayuki ARAI  Hitoshi KUROSU  Mamoru OHARA  Ryo SUZUKI  Satoshi FUKUMOTO  Kazuhiko IWASAKI  

Publication
IEICE TRANSACTIONS on Communications   Vol.E86-B    No.10    pp.2940-2947
Publication Date: 2003/10/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (IEICE/IEEE Joint Special Issue on Assurance Systems and Networks)
Category: Network Systems and Applications
Keyword: 
video conference system,  convolutional codes,  H.323,  Xcast,  packet loss,  

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Summary: 
In video conference systems over the Internet, audio and video data are often lost due to UDP packet losses, resulting in degradation of assurance. In this paper we describe a high-assurance video conference system applying the following two techniques: (1) packet loss recovery using convolutional codes, which improves the assurance of communication; and (2) Xcast, a multicast scheme that is designed for relatively small groups, reducing the bandwidth required for a multi-point conference. We added these functions to a GateKeeper (GK), a device used in conventional conference systems. Encoding/decoding and Xcast routing were then implemented as the upper layer for the UDP. We examined the functions of the system over the Internet in a multi-point conference between three sites around Tokyo, as well as a conference between Tokyo and Korea. We also investigated the effectiveness of the proposed system in experiments using an Internet simulator. Experimental results showed that the quality of received picture was improved in comparison with the case where no encoding schemes were applied.