Abstract:
An improved video conferencing system debundles the audio and the video and allows for a user to select which other conference stations will receive audio, which will receive video and which will receive both.

Description:
TECHNICAL FIELD 
     The present invention relates to video conferencing, and more specifically, to an improved technique of providing flexible video conferencing systems by allowing a party to the conference to specify various portions of a signal being transmitted from its conference station which are to be received by other conference stations. 
     BACKGROUND OF THE INVENTION 
     Video conferencing systems have come into widespread use in the past several years, particularly with the merging of computers and telecommunications. Specifically, there are now numerous personal computer type devices which can enable video conferencing over a telephone and/or data network. With Internet use growing at the rapid rate recently exhibited, it is expected that video conferencing systems will be even more widely used. 
     Basic video conferencing involves capturing audio and video information and transmitting the captured signals to one or more of other users in the conference. Each user in the conference receives and views one or more images, one being transmitted from each of the other conferees. The audio information from any conferee is typically broadcast to all other conferees. 
     In prior art video conferencing systems, the image and audio from a plurality of video cameras are merged by a conference bridge and transmitted to the numerous conference participants. Typically, the conference bridge and network indiscriminately mix all of the signals from each of the different video camera stations and transmit a composite image to the other stations. There exists no known technique of allowing any one or more users to control the particular signals received by any other conference station. 
     SUMMARY OF THE INVENTION 
     The above problems are overcome in accordance with the present invention which relates to a technique of permitting conferees to selectively transmit different portions of signals to different conferees. Specifically and with reference to FIG. 1, an exemplary conference among conference stations  101  through  104  is shown implemented via a conference bridge and connections  106  through  109 . Such connections may be facilitated over a data network. 
     In operation, each conference station  101  to  104  may debundle its outgoing signals so that the video and audio, as well as any other portions thereof, are separable by conference bridge  105 . Each of the conference stations  101  through  104  may then transmit signals indicating which of the other conferees should receive the audio, which should receive the video, and which should receive both. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts a plurality of conference stations  101  through  104  interconnected via a conference bridge  105 ; and 
     FIG. 2 depicts a high level functional diagram of an exemplary bridging arrangement for implementing the techniques of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a conference bridge  105  interconnecting a plurality of conference stations  101  through  104 . Although the conference stations are shown as each being connected to the conference bridge via a separate, dedicated connection, in fact, each may be connected via the telephone or a data network. 
     FIG. 2 shows a high level block diagram of an exemplary arrangement for implementing the techniques of the present invention. The system of FIG. 2 includes a conference bridge  201 , an exemplary demultiplexer  202 , audio and video processing  203  and  204 , respectively, and a bridging circuit  205 . Additionally, shown therein are three exemplary conference station interfaces  206 ,  207  and  208 . 
     In a practical system, there would be both a conference station interface (i.e.,  206 ) and a demultiplex, audio, and video block for each conferee. For purposes of explanation and simplicity, FIG. 2 does not show all of these items as associated with each conference station. 
     In operation, a signal arrives from a conference station over a communications link  108  and is demultiplexed by demultiplexer  202 . The demultiplexer is arranged to separate the audio from the video and may operate in accordance with theories of frequency division multiplexing, time division multiplexing, or any other technique. The video and audio are sent separately for processing to blocks  204  and  203  respectively, as indicated in FIG.  2 . 
     The bridging circuit  205  then receives both audio and video signals and, based upon its configuration as previously programmed, routes either the video, the audio, or both over communications lines  209  through  214  to conference station interfaces  206  through  208 . Each of the conference station interfaces  206  through  208  then multiplexes the audio and video signals together and transmits it out onto the communications lines  106 ,  107  and  109  for transmission to its corresponding conference station. 
     Bridging circuit  205  is a microprocessor controlled interconnection which is programmed via any suitable technique. For example, selection signals may be sent from the conference stations  101  through  104  at the beginning of the conference. Based upon such selection signals, the system determines which audio and video signals should be routed to which conference stations. For example, at the start of the conference, bridging circuit  205  could sequentially prompt each of the conference stations. First, the telephone numbers or data network addresses of all of the conference stations are obtained or inputted to bridging circuit  205  in accordance with any conventional technique. Bridging circuit  205  then sends a message to conference station  106  listing the three other conference stations and requesting a response regarding whether each of the conference stations should receive audio, video, or both. This prompting can be done via the telephone and touchtone entries, or via the computer interface with the user of each conference stations filling out a template. 
     After receipt of the appropriate information from each of the conference stations  101  through  104 , bridging circuit  205  is then configured to convey the appropriate connections such that the video and audio are transmitted to the appropriate other conference stations. For example, if conference station  101  requests that its audio be sent to all other conference stations but its video only be sent to conference station  104 , then bridging circuit  205  would configure itself to accomplish the same. Specifically, bridging circuit  205  would receive the input from video and audio processing  204  and  203  and transmit the audio to lines  209 ,  211  and  213 . The video, however, would only be transmitted to line  214 , but not line  210  and  212  such that the multiplex signal on lines  106  and  107  will contain no video. 
     In addition to prompting the users, the bridge may be configured in advance or the bridging circuit may actually be resident at one of the conference stations. The “master conference station” would then determine which conference stations receive audio and which receive video from each of the other conference stations. 
     While the above describes the preferred embodiments, various other modifications and additions will be apparent to those of skill in the art.