Abstract:
A stable telephone call barge-in without operator intervention is described wherein a telephone line is provided with two separate directory numbers. One directory number is the usual directory number associated with the line. The second directory number is considered the priority directory number which also translates in circuit switched telephony as the same line ID. Therefore, when a call is in a stable state, a person dialing the regular directory number will receive a busy signal. The person can then disconnect and dial the priority number. When the priority number is received, advantageously, a password is entered into the system to verify that the user of the priority number has permission to barge in. If the password is valid, the existing call is disconnected and the party barging in is connected to the called party. The other call may be placed on hold or alternatively may be disconnected with or without an announcement.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to the field of telephony and, more specifically, to a system and method that permits a user to barge into a currently established telephone call without the intervention of the operator.  
         BACKGROUND OF THE INVENTION  
         [0002]    In modem telephony, a “busy signal” is becoming more rare and more common at the same time. A telephone line that is used primarily for voice frequently included call waiting, which provides a calling third party with an audible ring signal. The called party may choose to answer or ignore the call waiting signal. If ignored, the called party continues to receive the audible ring signal. On the other hand, lines that are used for modem connections frequently do not have call waiting or disable call waiting when the user causes the modem to dial. These calls frequently have line occupancy times of more than an hour; way above the average voice call of 2 minutes. Thus, a calling party has a better chance to “get through” to the called party on a voice call, but little or no chance on a data call.  
           [0003]    Furthermore, a calling party receives a busy signal when a telephone set is off-hook and not connected to a call. Dial-tone is sent over the off-hook line for a predetermined time, followed by a “howler” tone for a further time. The line is then shut down, which precludes anyone getting through (until the phone is placed on switch-hook again). The caller can call the operator to verify the state of the line (operator busy-verify) by bridging onto the line and listening for voice (a scrambler is put on the operator&#39;s receiver side for privacy). Further, the operator may barge in on an existing call if the calling party presents a case for such drastic action.  
           [0004]    A calling third party receives a busy signal, and, because of the long hold time of some voice and data calls, can receive a busy or audible ring tone for a long period of time. If a person must reach the user of the telephone line, he or she must call the operator to perform either an operator busy verify or, in emergency situations, operator barge in.  
           [0005]    With the rise in hold time of stable telephone calls, operator intervention is becoming expensive to the operating companies. In cases where there is one phone line in a residence and a personal computer is connected to the Internet via one telephone line, there is currently no manner to barge in or verify unless there is a dire emergency and the operator is involved.  
         SUMMARY OF THE INVENTION  
         [0006]    This problem is solved and a technical advance is achieved in the art by a system and method that provides for call barge-in and verify without operator intervention. According to one exemplary embodiment of this invention, a telephone line wherein the user subscribes to this feature is provided with two separate directory numbers. One directory number comprises the normal or “published” directory number associated with the line. The second directory number comprises a “priority” directory number. When a call is in a stable state on the telephone line, a calling party dialing the regular directory number receives a busy signal. The calling party can then disconnect from the busy signal and dial the priority number. When the priority number is received, advantageously, a password is entered to verify that the user of the priority number has permission to barge in. If the password is valid, the extant call is interrupted and the barge-in party is connected to the called party. The other call may be placed on hold, or, alternatively, may be disconnected with or without an announcement.  
           [0007]    According to another embodiment of this invention, a party may barge in by dialing a preemption number and password, which may advantageously cause a howler tone to be applied to the called line. The called party then knows to go on-hook, the original call is disconnected and the barge-in call is connected in the usual manner.  
           [0008]    According to a third embodiment of this invention, when a calling party receives a busy signal, the party disconnects and dials an 800 number. The calling party is then prompted for the destination directory number and a password. Call processing then proceeds according to one of the previous embodiments. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    A more complete understanding of the invention may be obtained from a consideration of the following description taken in conjunction with the drawings in which:  
         [0010]    [0010]FIG. 1 is a block diagram of a telephone network in which several embodiments of the current invention may be implemented;  
         [0011]    [0011]FIG. 2 is a flowchart of a first embodiment of this invention which may be implemented in the telecommunications system of FIG. 1;  
         [0012]    [0012]FIG. 3 is a second embodiment of the current invention which may be implemented in the telecommunications system of FIG. 1; and  
         [0013]    [0013]FIG. 4 is a flowchart of a third embodiment of the current invention which may be implemented in the telecommunications system of FIG. 1.  
     
    
     DETAILED DESCRIPTION  
       [0014]    Turning now to FIG. 1, a block diagram of a telephone network  10 , in which several embodiments of the current invention may be implemented, is illustrated. Telephone network comprises a plurality of local telephone switching systems (“local switches”) represented by local switches  12 ,  14  and  16 . All local switches are connected to the public switched telephone network (PSTN)  18 . An Internet service provider (ISP)  20  is also connected to PSTN  18  and to the Internet  21 . Further, each local switch  12 ,  14 , and  16  is connected to a signaling network  22 . Signaling network  22  comprises, for example, Signaling System  7  (SS 7 ) network as is well known in the art. A network control point  24  is connected to signaling network  22 .  
         [0015]    In order to explain the exemplary embodiments of this invention, three telephones are illustrated connected to telephone network  10 . Telephone  26  is connected to local switch  12  by line  28  and has a telephone number (directory number or DN) of 630-555-1234. Telephone  30  is connected to local switch  14 . Telephone  32  is connected to local switch  16  and has an exemplary DN of 312-555-3124. To complete the description of the exemplary embodiment, caller ID display  34  and personal computer (PC) are also connected to line  28 , as is known in the art.  
         [0016]    The general principles of this invention are illustrated in telephone network  10  in which telephone  26  subscribes to a feature for telephone call barge-in without operator intervention. For purposes of explaining this invention, users of telephone  26  and  30  are engaged in a telephone call. The user of telephone  32  (“calling party”) wishes to contact the user of telephone  26  (“called party”). The calling party dials the normal DN (630-555-1234) of telephone  26 , the call is routed through local switch  16 , PSTN  18 , and local switch  12  as is known in the art. Local switch  12  checks the status of line  28  and reports that line  28  is busy. This busy state is reported back to local switch  16  which provides a busy signal to the calling party. According to the prior art, if telephone  26  does not subscribe to call waiting or, alternatively, chooses to ignore call waiting, the user of telephone  32  has only the option of calling the operator and asking for intervention.  
         [0017]    According to this invention, the user of telephone  32  may dial a special directory number, 630-555-4321 in this exemplary embodiment, associated with telephone line  28 . When this number is dialed, a call is set up between local switch  16  and local switch  12  according to the prior art. However, instead of reporting busy signal back to local switch  16 , the established call is disconnected. The connection to telephone  30  is disconnected by putting the connection on hold or dropping the call. Advantageously, an announcement may be made from local switch  12  and a message displayed on caller I) display  34  of the calling telephone number (312-555-3124) that the special directory number has been dialed, giving the called party an opportunity to either disconnect the call to telephone  30  or alternatively put the interrupted call on hold.  
         [0018]    For purposes of explaining an alternative embodiment of this invention, PC  36  is connected to the Internet  21  via ISP  20 . The calling party at telephone  32  receives a busy signal when trying to call telephone  26  on its DN (630-555-1234) for the duration of the PC connection. The user then dials an 800 telephone number, for example 1-800-BARGEIN. Local switch  16  sends a message through signaling network  22  to a network control point  24  to determine instructions for setting up a call when this number is dialed, as is known in the art. Network control point  24  prompts the user of telephone  32  for the desired telephone to be barged into, (i.e., 630-555-1234 for telephone  26 ) and advantageously a PIN or a password. The signaling network then causes the call between telephone  26  and ISP  20  to be suspended or dropped and a call completed between local switch  16  and local switch  12  through PSTN  18  according to normal practice. In this manner, a user may barge into a home phone or alternatively to someone else&#39;s phone provided they have enough information (preferably including a password or a PIN). This is quite useful in today&#39;s lengthening hold times and would be most useful in cases where the user of telephone  26  is connected to an Internet service provider  20 . Optionally, a determination may be made whether modem signaling is present on the line. If it is, a disconnect signal may be sent in both directions, clearing the line for the barge-in call.  
         [0019]    [0019]FIG. 2 is a flow diagram of actions taken in local switch  12  to provide the feature of telephone call barge-in without operator intervention. In FIG. 2, a stable call, for example between telephone  26  and  30 , is established in box  200 . In action box  202 , a new incoming call arrives from for example telephone  32 . A determination is made in decision diamond  204  whether the dialed number is the preemption DN number (630-555-4321). If the dialed number is not the preemption number then the normal call treatment for that particular telephone, i.e., call waiting, busy, voice mail routine as is known in the art is performed in action box  206 .  
         [0020]    If, in decision diamond  204 , the dialed DN is the preemption DN an announcement is played to the caller to enter a password or PIN in action box  208 . The PIN is captured in action box  210  and a determination is made in decision diamond  212  whether the PIN or password is valid. If the password is not valid, then call waiting, voice mail, etc. is performed in action box  206 .  
         [0021]    If the password is valid then processing moves to action box  214  where an announcement is provided to the stable call (both front party and back party). For example, “Your call is being interrupted” or alternative a tone or some other method is shown and/or a caller ID display  34  is alerted. Processing moves to action box  216  where the stable call is disconnected; that is, the connection to telephone  30  is ended.  
         [0022]    A call is then connected between telephone  30  and telephone  26  in action box  218 . Processing waits until disconnect is received in decision diamond  220 . If disconnect is received, i.e., the user of telephone  26  put the receiver on hook, then power ring is applied to the line and the call is connected to telephone  30  in action box  222 . If disconnect is not received within a predetermined time, the call is automatically connected in action box  224 .  
         [0023]    Turning now to FIG. 3, another exemplary embodiment of this invention is shown. This embodiment of this invention takes place in local switch  12 . In the flowchart of FIG. 3, line  28  is a “high and wet” line, meaning line  28  to telephone  26  is off-hook but not connected to any party. Processing moves to action box  302  where a new incoming call arrives for the high and wet line  28 . A determination is made in decision diamond  304  if the dialed number is the preemption number (630-555-4321). If not, processing continues to action box  306  where normal line busy activity is performed for that particular subscriber (i.e., voice mail, busy, call waiting, call waiting with caller ID, etc.) If, in decision diamond  304 , the dialed DN is the preemption number then processing moves to action box  308  where an announcement is played to the caller to enter a password or PIN. Processing moves to action box  310  where the PIN is captured and then to decision diamond  312  where a determination is made if the password is valid. If the password is not valid, then the normal line busy treatment is performed in action box  306 .  
         [0024]    If, in decision diamond  312 , the password is valid then processing moves to action box  314  where, for example, a howler tone as is known in the art is provided to the line to telephone  26 . Other forms of interruption such as a call waiting tone or call waiting on caller ID is displayed on  34  may also be provided. The local switch  12  then waits for an on-hook from telephone  26  for a predetermined time period.  
         [0025]    A determination is made in decision diamond  318  to determine whether an on-hook was received. If an on-hook was received, then processing proceeds to action box  320  where power ring is applied to the line and the call is connected to telephone  32  through telephone network  10 .  
         [0026]    If on-hook is not received within a predetermined period of time it is determined in decision diamond  318  that an announcement is played to the caller. Processing proceeds to action box  322  where an announcement is played to the caller that the call is being connected to a line that is already off hook. A call is then established from telephone  26  to telephone  32  in action box  324 . This embodiment is useful to replace operator busy-verify.  
         [0027]    Turning now to FIG. 4, another alternative embodiment of the present invention is shown. In this embodiment, the user of telephone  32  receives a busy signal in the action box  400 . The user of telephone  32  hangs up and then dials an 800 number in action box  402 . The 800 number is routed from local switch through PSTN and signaling network to network control point  24 . Network control point  24  then prompts the user of telephone  32  for the DN which is calling for barge-in service. In decision diamond  406 , a determination can be made whether the desired DN has permission to use the service and whether the DN is valid. If the DN is not valid, then the call may be ended or the caller may be prompted to try again in action box  408 .  
         [0028]    If the DN is valid in decision diamond  406 , then the user is prompted by network control point  24  for a PIN or password in action box  410 . The PIN or password is then validated in decision diamond  412 . If the PIN or password is not valid, then the call may be ended or the user prompted to try again in action box  408 .  
         [0029]    If the PIN is valid in decision diamond  412 , then network control point  24  directs the end office (local switch  12 ) to interrupt the call. The call interrupt may be a howler tone as described above, a voice interrupt or other tone as is known in the art. In action box  416 , the network control point  24  waits for an on-hook signal back from telephone  26 . If an on-hook is received as determined by decision diamond  18 , then power ring is applied to line for telephone  26  and the call is connected from telephone  30  through telephone  26 . Network control point  28  then drops off the call. If on-hook is not received in decision diamond  418 , then an announcement is made in  422  that the caller is being connected to a line that is off hook and in action box  424  the call is connected.  
         [0030]    It is to be understood that the above-described invention embodiments are merely aspects of the invention and that many variations may be made by those skilled in the art. For example, the call that is barging in may be bridged onto the line as a third party. It is, therefore, intended that such variations be included within the scope of the following claims.