David A. Berkley
Acoust. Res. Dept., AT&T Bell Labs., 600 Mountain Ave., Murray Hill, NJ 07974-0636
Video teleconferencing, especially that supported by inexpensive low-bit rate connections, is an exploding area. It is clear that there are severe trade-offs to be made as bit-rate is lowered. However, although everyone agrees that audio is a vital part of audio/video teleconferencing, little is understood about what trade-offs are involved in optimizing the audio and the relationship between the audio and video on a specific type of conference link. The relationship between audio and video transmission delay, camera tracking errors and lag, audio bandwidth and other related issues are discussed. Implementation of experiments, based on the HuMaNet [D. A. Berkley and J. L. Flanagan, AT&T Tech. J. 69, 87--97 (1990)] platform, is also described.