Multiplex communications – Special services – Conferencing
Reexamination Certificate
2011-08-23
2011-08-23
Cho, Hong (Department: 2467)
Multiplex communications
Special services
Conferencing
C370S286000
Reexamination Certificate
active
08005023
ABSTRACT:
A “Client-Side Echo Canceller” provides a unique system and method for reducing Multipoint Control Unit (MCU) computational overhead in a multi-point audio conference. In general, the local audio input signal of each client is transmitted in real-time to the MCU. The MCU then combines the audio input signals of all clients to create a single composite signal that is transmitted back to all clients in real-time. Each client then locally processes the composite signal to remove each client's local contribution to the composite signal prior to local playback in order to eliminate a local echo of each client's local audio input. In various embodiments, local cancellation of the local audio input from the composite signal is performed on either a time domain or a transform domain representation of the composite signal. Further, since each client receives the same signal, MCU transmission bandwidth can be reduced via multicast transmissions.
REFERENCES:
patent: 4707824 (1987-11-01), Kanemasa
patent: 4969144 (1990-11-01), Blackwell et al.
patent: 5305307 (1994-04-01), Chu
patent: 5434912 (1995-07-01), Boyer et al.
patent: 5796819 (1998-08-01), Romesburg
patent: 6327276 (2001-12-01), Robert et al.
patent: 6816592 (2004-11-01), Kirla
patent: 6931123 (2005-08-01), Hughes
patent: 6947773 (2005-09-01), Novorita
patent: 6987992 (2006-01-01), Hundal
patent: 2002/0123895 (2002-09-01), Potekhin
patent: 2003/0123399 (2003-07-01), Zhang et al.
patent: 2005/0094580 (2005-05-01), Kumar
patent: 2006/0247045 (2006-11-01), Jeong
patent: 1715669 (2006-10-01), None
patent: WO2006111370 (2006-10-01), None
Gentile, K., W. Daniel, L. Worthington, J. Blatnik, Audio conferencing quality of service issues within the transition from circuit-switched to packet-switched, Jul. 2008.
Gong, F., Multipoint Multipoint audio and video control for packet-based multimedia conferencing, Proc. of the 2nd ACM Int'l Conf. on Multimedia, 1994, San Francisco, California, United States, pp. 425-432.
Hirasawa, J., T. Amakasu, S. Yamamoto, Y. Yamaguchi, and A. Imamura, Cyber attendant system with spontaneous speech interface, Speech and Audio Signal Processing Technologies, NTT Technical Review, Special Feature, Mar. 2004, pp. 64-69, vol. 2, No. 3.
Hiwasaki, Y., T. Mori, H. Ohmuro, J. Ikedo, D. Tokumoto, and A. Kataoka, Scalable speech coding technology for high-quality ubiquitous communications, Speech and Audio Signal Processing Technologies, NTT Technical Review, Special Feature, Mar. 2004, pp. 53-58, vol. 2, No. 3.
ITU-T Rec. G.722.1, “Coding at 24 and 32 kbit/s for hands-free operation in systems with low frame loss,” Sep. 1999.
ITU-T Rec. H.323, “Packet-based multimedia communication systems,” Nov. 2000.
ITU-T Rec. P.800, “Methods for subjective determination of transmission quality,” Aug. 1996.
Mizuno, H., H. Asano, M. Isogai, M. Hasebe, and M. Abe, Text-to-speech sythesis technology using corpus-based approach, Speech and Audio Signal Processing Technologies, NTT Technical Review, Special Feature, Mar. 2004, pp. 70-75, vol. 2, No. 3.
Sakauchi, S., Y. Haneda, M. Okamoto, J. Sasaki, and A. Kataoka, Echo canceller with noise reduction provides comfortable hands'free telecommunication in noisy environments, Speech and Audio Signal Processing Technologies, NTT Technical Review, Special Feature, Mar. 2004, pp. 59-63, vol. 2, No. 3.
Smith, P. J., P. Kabal, M.L. Blostein, and R. Rabipour, Tandem free voip conferencing: A bridge to next-generation networks, IEEE Communication Magnize, May 2003, vol. 41, No. 5, pp. 136-145.
Smith, P. J., P. Kabal, and R. Rabipour, Speaker selection for tandem-free operation voip conference bridges, in Proc. IEEE Workshop Speech Coding, Oct. 2002, pp. 120-122.
Takahashi, S., M. Okamoto, and H. Ohara, Speech and audio signal processing for a user-friendly comfortable, convenient telecommunication environment, Speech and Audio Signal Processing Technologies, NTT Technical Review, Special Feature, Mar. 2004, pp. 50-52, vol. 2, No. 3.
Xu, X., L. He, D. Florencio, and Y. Rui, Pass: Peer-aware silence suppression for internet voice conferences, IEEE Int'l Conf. on Multimedia & Expo, 2006.
Florencio Dinei
He Li-wei
Li Junlin
Cho Hong
Lyon & Harr LLP
Microsoft Corporation
Watson Mark A.
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