Abstract:
During a conference call, identifying a communication terminal, and inhibiting transmission of audio signals to the conference call by the identified communication terminal in response to operations performed by another communication terminal.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to telephones in general, and in particular, to the capability of controlling conference calls.  
         BACKGROUND OF THE INVENTION  
         [0002]    Within the prior art, conference calls are well known. The problem that can arise during a conference call is that one of the parties to the conference call may be performing an act or their telephone may be performing an act that is disrupting the conference call. One such situation is when a party puts the call on hold and music-on-hold is active. The rest of the parties of the conference call have a difficult time communicating over the music until the person reenters the conference call and removes the call on hold feature. Another situation is when a user is on a cellular telephone which is generating noise. The cellular telephone user may not be aware that the cellular telephone is even causing a problem for others on the conference call or may not be able to mute their cellular phone because of environmental conditions or because the phone does not have this capability. In these types of situations, all of the parties to the conference call experience degradation in the quality of the communications.  
         SUMMARY OF THE INVENTION  
         [0003]    This invention is directed to solving these and other problems and disadvantages of the prior art. According to an embodiment of the invention, a user to the conference call can identify a party that is disrupting the conference call and inhibit the transmission of audio signals from the identified party. Advantageously, only a simple digital telephone station with an alphanumeric display is required to perform these activities. Advantageously, the user of the telephone that is disrupting the conference call still can hear the telephone call; and if they wish to reenter the conference call, they can press a key on their telephone which will send a multi-frequency tone that enables them to speak on the conference call.  
           [0004]    These and other advantages and features of the present invention will become apparent from the following description of an illustrative embodiment of the invention taken together with the drawing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0005]    [0005]FIG. 1 illustrates, in block diagram form, an embodiment of a telecommunication system utilizing the present invention; and  
         [0006]    [0006]FIGS. 2 and 3 illustrate, in flowchart form, the steps performed by the control computer in implementing an embodiment of the invention.  
     
    
     DETAILED DESCRIPTION  
       [0007]    [0007]FIG. 1 illustrates an embodiment of a system for implementing the invention. PBX  100  (also referred to as an enterprise communication switching system or a business communication switching system) is illustrated as having a number of telephones interconnected to switching network  102  via line circuits  114  and  117 . In addition, PBX  100  is interconnected to cellular switching system  118  via digital trunk  104 . One skilled in the art would realize that the interconnection to cellular switching system  118  could well be through the public telephone network. In addition, PBX  100  could interconnect to telephones connected to the public switching system. Cellular telephone  119  is in communication with cellular switching system  118 . In addition, PBX  100  has a conference circuit  106  and tone detector  116 . Both of these circuits are well known to those skilled in the art.  
         [0008]    To better understand the operation of PBX  100  with respect to conference calls, consider the following example. Station set  103 , station set  127 , and station set  128  are engaged in a conference call with cellular telephone  119 . The conference call is enabled by conference circuit  106  under control of control computer  101 . Switching network  102  provides the necessary paths between the participating telephones on the conference call and conference circuit  106 . Assume, that cellular telephone  119  is at a distance from cellular switching system  118  and the radio communication between cellular telephone  119  and cellular switching system  118  is disrupted on a periodic basis. This causes interference with the conference call because of noise being transmitted to the conference call from cellular switching system  118 . In response to cellular telephone  119  disrupting the conference call, the user of station set  103  presses button  111  which is the “conference display” button. Each time the user presses button  111 , another participant in the conference call is displayed by name and telephone number on alphanumeric display  109 . When information for cellular telephone  119  is displayed on alphanumeric display  109 , the user of station set  103  activates button  108  which is the “far end mute” button. Control computer  101  is responsive to this actuation to transmit control messages to conference circuit  106  to inhibit the audio samples being received from cellular telephone  119  from being part of the conference call. In addition, control computer  101  enables a tone detector  116  to receive the audio samples from cellular telephone  119  via switching network  102 . If the user of cellular telephone  119  wants to speak on the conference call again, the user of cellular telephone  119  presses the “#” key. Tone detector  116  is responsive to the actuation of the “#” key to transmit a control message to control computer  101 . In response, control computer  101  transmits a control message to conference circuit  106  to enable the audio samples being received from cellular telephone  119  to once again be part of the conference call. In addition, control computer  101  removes tone detector  116  from monitoring the audio samples from cellular telephone  119  by controlling switching network  102 .  
         [0009]    In this example, the users of station sets  103 ,  127 , and  128  can also unmute cellular telephone  119 . To unmute cellular telephone  119 , the user of station set  103  again presses button  111  until the name and telephone number for cellular telephone  119  are displayed on alphanumeric display  109 . When the information for cellular telephone  119  is displayed on alphanumeric display  109 , the user of station set  103  again activates button  108  which is the “far end mute” button. Control computer  101  is responsive to this second actuation to transmit control messages to conference circuit  106  to again make cellular telephone  119  part of the conference call. In addition, control computer  101  disables tone detector  116 .  
         [0010]    [0010]FIGS. 2 and 3 illustrate, in flow chart form, the steps performed by control computer  101  in implementing one embodiment of the invention. After being started, decision block  201  checks to see if a conference call is being set up. A conference call would be set up in a manner well known to those skilled in the art. If the answer is no, control is transferred to block  202  that performs normal processing before returning call control back to decision block  201 . If the answer is yes in decision block  201 , block  203  sets up the conference call before transferring control to decision block  204 . Decision block  204  determines if the “conference display” button has been actuated on any of the telephones that are part of the conference call. If the answer is yes, control is transferred to block  206  which displays another telephone on the conference to the telephone that actuated the “conference display” button. Note, that the functions of block  206  are to take the other telephones on the conference sequentially in some manner so that all of them are displayed in response to each actuation of the “conference display” button. After execution of block  206 , decision block  207  determines if the “far end mute” button has been actuated on the telephone that actuated the “conference display” button. If the answer is no, control is transferred back to decision block  204  to once again determine if the user has actuated the conference display button. The user repeatedly activates the conference display button so as to step through all of the telephones on the conference call.  
         [0011]    Returning to decision block  207 , if the “far end mute” button has been actuated on the telephone whose “conference display” button is actuated, control is transferred to decision block  208  of FIG. 2. Decision block  208  determines if the displayed telephone is already marked as being muted. If the answer is no, control is transferred to block  209 . Block  209  mutes the displayed telephone on the conference so that the displayed telephone can no longer input audio information into the conference. Then, block  211  initiates a tone detector on the path from the muted telephone. One skilled in the art can readily see that the signaling from the muted telephone could be other than multi-frequency tones and that block  211  could be suitably adjusted to handle these other kinds of signals. After execution of block  211 , control is transferred back to decision block  204  of FIG. 2. Returning to decision block  208 , if the answer in decision block  208  is that the telephone has already been muted, control is transferred to block  212  which unmutes the displayed telephone on the conference. This unmuting know allows the displayed telephone to speak on the conference call. Next, block  213  removes the tone detector from monitoring the displayed telephone before returning control back to decision block  204 .  
         [0012]    Returning to decision block  204 , if the answer is no that the “conference display” button has not been actuated on any of the telephones that are party to the conference, control is transferred to decision block  309  of FIG. 3. Decision block  309  determines whether the conference display operation has exceeded a predefined time. Advantageously, this predefined time may be 60 seconds. Once the user has actuated the conference display button, the user has 60 seconds to proceed with the operations of displaying the next conference member or muting the currently displayed telephone telephone. If the user fails to perform any additional operations, control is transferred from decision block  309  to block  311 . However, if the decision is made in decision block  309  that the predefined amount of time has not been exceeded, control is transferred back to decision block  204  of FIG. 2. If the decision is made in decision block  309  that the predefined time has been exceeded, control is transferred to block  311 . Block  311  turns off the conference display LED, and block  312  returns the telephone that had actuated the conference display button to the normal state before transferring control to decision block  303 .  
         [0013]    The decision block  303  determines if the “#” has been actuated on the muted telephone. If the answer is yes, control is transferred to block  304  which enables the muted telephone back on the conference before transferring control back to decision block  204 . If the answer in decision block  303  is no, control is transferred to decision block  306 . Decision block  306  determines if the conference call has been terminated in a manner well known to those skilled in the art. If the answer is no that the conference call has not been terminated, block  307  performs normal processing before transferring control back to decision block  204  of FIG. 2. If the conference call has been terminated, block  308  performs normal processing before returning control back to decision block  201  of FIG. 2.  
         [0014]    Of course, various changes and modifications to the illustrative embodiment described above will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the following claims except in so far as limited by the prior art.