Patent Publication Number: US-2007121862-A1

Title: Telephone exchange apparatus and incoming call control method for telephone exchange apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2005-271097, filed Sep. 16, 2005, the entire contents of which are incorporated herein by reference.  
     BACKGROUND  
      1. Field  
      One embodiment of the invention relates to a telephone exchange apparatus having a function in which after an operation of making an outgoing call is performed on a telephone terminal, an incoming call reservation key provided on the telephone terminal is pressed, whereby an incoming call which arrives from a telephone terminal which is a destination of the outgoing call is accepted, on a priority basis, on the telephone terminal which is a source of the outgoing call, and an incoming call control method for the telephone exchange apparatus.  
      2. Description of the Related Art  
      In a telephone exchange apparatus such as a key telephone apparatus, when an outgoing call is made from an internal line terminal to a network, an outgoing telephone number of the internal line terminal which is a source of the outgoing call is notified to a telephone terminal on the network side which is a destination of an incoming call. It is assumed that the telephone terminal on the network side uses the outgoing telephone number and makes an outgoing call to the internal line terminal included in the telephone exchange apparatus. Then, the telephone exchange apparatus uniformly distributes, according to the outgoing telephone number included in an incoming call, the incoming call to a plurality of internal line terminals in a preset group.  
      In the telephone exchange apparatus, however, the incoming call is received and distributed within the group under the same condition and thus a user who is different from a user of the internal line terminal from which the outgoing call is made to the telephone terminal on the network may answer the incoming call. In this case, the user having received the incoming call needs to first make conversion with a caller and ask the caller whom he/she wants to and then have the user whom the caller wants to speak to take over the service or transfer the incoming call to a desired internal line terminal, causing a troublesome operation.  
      In view of this, conventionally, a following technique is proposed. That is, after a user on an internal line terminal performs an operation of making an outgoing call to a network, a specific key provided on the internal line terminal is pressed, whereby when a returned incoming call is received from a telephone terminal on the network side, the incoming call is received only by the internal line terminal where the specific key operation is performed (for example, Jpn. Pat. Appln. KOKAI Publication No. 2002-209238).  
      In the aforementioned technique, however, the user on the internal line terminal where the special key operation is performed may be away from his/her desk or may be out of the office. In this case, even if a returned incoming call is made to the internal line terminal where the specific key operation is performed, the call cannot be answered. Although there is a technique for transferring a returned incoming call to an internal line terminal at a location where the user in transit is present, transfer registration needs to be made separately and thus it is inconvenient. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
      A general architecture that implements the various feature of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.  
       FIG. 1  is a block diagram showing a configuration of an exchange system according to a first embodiment of the present invention;  
       FIG. 2  is a diagram showing an example of contents stored in an outgoing history database shown in  FIG. 1 ;  
       FIG. 3  is a schematic sequence diagram showing an operation of transmitting/receiving, when an outgoing call is made from an internal line terminal to a public network, information between the internal line terminal, a main apparatus, and an external telephone terminal in the first embodiment;  
       FIG. 4  is a flowchart showing procedures of a control process of a central control unit performed upon making registration to transfer an incoming call in the first embodiment;  
       FIG. 5  is a schematic sequence diagram showing an operation of transmitting/receiving, when an incoming call from the external telephone terminal on the public network arrives, information between the internal line terminal, the main apparatus, and the external telephone terminal in the first embodiment;  
       FIG. 6  is a flowchart showing procedures of a control process of the central control unit performed upon transferring an incoming call in the first embodiment; and  
       FIG. 7  is a flowchart, according to a second embodiment of the present invention, showing steps of a control process of the central control unit performed when an internal line terminal which is a destination of transfer of an incoming call cannot receive the call.  
    
    
     DETAILED DESCRIPTION  
      Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, a telephone exchange apparatus which performs an exchange process between a plurality of telephone terminals, in which an operation of making an outgoing call is performed on a first telephone terminal among the plurality of telephone terminals and thereafter an incoming call reservation key provided on the first telephone terminal is pressed, whereby when an incoming call including a called party&#39;s ID which identifies a destination of the outgoing-call arrives, the first telephone terminal can accept the incoming call, the apparatus comprising: a memory which stores a management table in which a terminal ID of the first telephone terminal, the called party&#39;s ID, and a terminal ID of the second telephone terminal are associated with one another, when transfer registration is made to transfer the incoming call including the called party&#39;s ID to a second telephone terminal which is different from the first telephone terminal after the incoming call reservation key is pressed on the first telephone terminal; and a controller which refers to the management table based on the called party&#39;s ID and identifies the terminal ID of the first telephone terminal which is associated with the called party&#39;s ID based on a result of the reference, and performs incoming call control on the second telephone terminal which is associated with the terminal ID of the first telephone terminal, when the incoming call including the called party&#39;s ID arrives.  
     FIRST EMBODIMENT  
       FIG. 1  is a block diagram showing the configuration of an exchange system according to a first embodiment of the present invention, in which reference numeral  1  denotes a main apparatus.  
      The main apparatus  1  includes an external line interface unit  11 , an internal line interface unit  12 , a time switch  13 , a central control unit  14 , and a storage unit  15 . Among them, the external line interface unit  11 , the internal line interface unit  12 , and the central control unit  14  are interconnected to one another via a control bus  16 . The external line interface unit  11 , the internal line interface unit  12 , and the time switch  13  are interconnected to one another via an audio bus  17 .  
      The external line interface unit  11  is connected to a public network PNW via a subscriber line SL and performs, for example, a process of establishing a call with the public network PNW.  
      The internal line interface unit  12  includes a plurality of internal lines EL 1  to ELm (m is a natural number). To the internal lines EL 1  to ELm are connected internal line terminals DKT 1  to DKTm, respectively. For the internal line terminals DKT 1  to DKTm, digital key telephones, for example, are used. The internal line interface unit  12  performs, for example, an incoming/outgoing call process on the internal line terminals DKT 1  to DKTm and a process of transferring a digital signal.  
      The time switch  13  performs, in response to an instruction from the central control unit  14 , channel switching on a digital signal to be transmitted between the external line interface unit  11  and the internal line interface unit  12  via the audio bus  17 .  
      The central control unit  14  performs, for example, an outgoing call process in response to a call request from the internal line terminals DKT 1  to DKTm, a normal incoming call process in response to an external incoming call from the subscriber line SL, and a transfer process between the internal line terminals DKT 1  to DKTm.  
      In the storage unit  15 , control data necessary for control processes of the central control unit  14  is stored.  
      In the meanwhile, the central control unit  14  is configured to include a table creation unit  141  and an incoming call control unit  142  in the first embodiment. The table creation unit  141  creates a table in which, when an operation of making an outgoing call to the public network PNW is performed on the internal line terminal DKT 1 , for example, and thereafter an incoming call reservation key  21  for making a reservation for an incoming call is pressed to make registration to transfer an incoming call to the internal line terminal DKTm, a terminal number ( 200 ) which serves as a terminal ID of the internal line terminal DKT 1 , a called party&#39;s dial number which serves as an ID of a called party to which the outgoing call is made, and a terminal number ( 299 ) of the internal line terminal DKTm which is a destination of transfer of the incoming call are associated with one another. Then, the table creation unit  141  stores the table in an outgoing history database  151  of the storage unit  15 . Note that in the outgoing history database  151 , a table such as the one shown in  FIG. 2  is stored.  
      When an incoming call including an outgoing telephone number arrives from the public network PNW, the incoming call control unit  142  determines whether the outgoing telephone number matches any of called parties&#39; dial numbers stored in the outgoing history database  151 . If it does, the incoming call control unit  142  identifies the terminal number of the internal line terminal DKT 1  which is associated with the called party&#39;s dial number and performs incoming call control on the internal line terminal DKTm which is associated with the terminal number of the internal line terminal DKT 1 .  
      Now, the operation of a system configured in the above-described manner will be described.  
       FIG. 3  is a schematic sequence diagram showing an operation of, when an outgoing call is made from the internal line terminal DKT 1  to the public network PNW, transmitting/receiving information among the internal line terminal DKT 1 , the main apparatus  1 , and an external telephone terminal TT 1 .  FIG. 4  is a flowchart showing the procedures of a control process of the central control unit  14  performed upon making registration to transfer an incoming call.  
      It is assumed that a user on the internal line terminal DKT 1  performs the operation of dialing a telephone number “042-585-3625” to make a call to a user on the external telephone terminal TT 1 . Then, a signal for requesting establishment of the communication is transmitted from the internal line terminal DKT 1  to the main apparatus  1 . Once the main apparatus  1  has received the communication establishment request signal, the main apparatus  1  transmits the communication establishment request signal to the public network PNW.  
      Once the public network PNW has received the communication establishment request signal, the public network PNW calls up the external telephone terminal TT 1  which is the destination of an incoming call. Here, it is assumed that the external telephone terminal TT 1 , the destination of an incoming call, is busy or not answered within a certain period of time.  
      Then, it is assumed that in this state the user on the internal line terminal DKT 1  presses the incoming call reservation key  21 . In response to this, the central control unit  14  proceeds from block ST 4   a  to block ST 4   b  where input of data on the destination of transfer of the incoming call by the user is accepted.  
      Here, the user inputs, for example, “299” which is the terminal number of the internal line terminal DKTm. The central control unit  14  displays the inputted terminal number “299” on an LCD of the internal line terminal DKT 1 . When, in this state, the user presses the incoming call reservation key  21  on the internal line terminal DKT 1 , the central control unit  14  proceeds from block ST 4   c  to block ST 4   d  where a table is created in which the terminal number ( 200 ) of the internal line terminal DKT 1 , the called party&#39;s dial number, and the terminal number ( 299 ) of the internal line terminal DKTm which is the destination of transfer of the incoming call are associated with one another, and the table is stored in the outgoing history database  151  of the storage unit  15 .  
      Thereafter, when the user presses the incoming call reservation key  21  on the internal line terminal DKT 1 , the central control unit  14  proceeds from block ST 4   e  to block ST 4   f  where the table which is stored in the outgoing history database  151  and in which the terminal number ( 200 ) of the internal line terminal DKT 1 , the called party&#39;s dial number, and the terminal number ( 299 ) of the internal line terminal DKTm which is the destination of transfer of the incoming call are associated with one another is deleted.  
      On the other hand, if, in the block ST 4   e , the user places the internal line terminal DKT 1  on hook state, the central control unit  14  ends the process with the aforementioned table being registered in the outgoing history database  151 .  
      If, in the block ST 4   a , the user places the internal line terminal DKT 1  on hook without pressing the incoming call reservation key  21 , the central control unit  14  ends the process there. If, in the block ST 4   b , after pressing the incoming call reservation key  21  on the internal line terminal DKT 1  the user places the internal line terminal DKT 1  on hook without inputting data on the destination of transfer of the incoming call, the central control unit  14  makes a setting as usual such that a returned incoming call from the external telephone terminal TT 1  is received on the internal line terminal DKT 1  (block ST 4   g ).  
       FIG. 5  is a schematic sequence diagram showing an operation of, when an incoming call from the external telephone terminal TT 1  on the public network PNW arrives, transmitting/receiving information among the internal line terminal DKT 1 , the main apparatus  1 , and the external telephone terminal TT 1 .  FIG. 6  is a flowchart showing the procedures of a control process of the central control unit  14  performed upon transferring an incoming call.  
      Now, for example, as shown in  FIG. 5 , it is assumed that in response to an outgoing call from the external telephone terminal TT 1 , an incoming call which includes an outgoing telephone number arrives on the main apparatus  1  from the public network PNW.  
      In this case, the central control unit  14  of the main apparatus  1  determines whether an outgoing telephone number is included in the incoming call (block ST 6   a ). If an outgoing telephone number is included (present), the central control unit  14  extracts the outgoing telephone number from the incoming call and determines whether the outgoing telephone number matches any of called parties&#39; dial numbers stored in the outgoing history database  151  (block ST 6   b ). In this example, since the dial number of the external telephone terminal TT 1  is registered so as to be associated with the terminal number of the internal line terminal DKT 1 , the central control unit  14  reads from the outgoing history database  151  the destination of the incoming call which is associated with the outgoing telephone number (block ST 6   c ) and transmits incoming call data to the internal line terminal DKTm which is the destination of the incoming call and allows the internal line terminal DKTm to generate an incoming call alarm. In this case, a ringtone different from that of the internal line terminal DKT 1  sounds or a special message is displayed on a LCD.  
      If, in the block ST 6   a , an outgoing telephone number cannot be received or if, in the block ST 6   b , the outgoing telephone number is not registered in the outgoing history database  151 , the central control unit  14  allows a destination of an incoming call specified by a usual function setting or the like to sound (block ST 6   d ).  
      As described above, in the first embodiment, when an operation of making an outgoing call to the external telephone terminal TT 1  is performed on the internal line terminal DKT 1  and thereafter the incoming call reservation key  21  provided on the internal line terminal DKT 1  is pressed to make transfer registration to transfer an incoming call including an outgoing telephone number of the external telephone terminal TT 1  to the internal line terminal DKTm, the central control unit  14  of the main apparatus  1  stores a table in which the terminal number of the internal line terminal DKT 1 , a called party&#39;s dial number, and the terminal number of the internal line terminal DKTm which is the destination of transfer of the incoming call are associated with one another, in the outgoing history database  151  and manages the table. Then, when an incoming call including an outgoing telephone number from the external telephone terminal TT 1  arrives, the central control unit  14  determines whether the outgoing telephone number matches any of called parties&#39; dial numbers stored in the outgoing history database  151 . If it does, the incoming call is automatically transferred to and received on the internal line terminal DKTm which is the destination of transfer of the incoming call.  
      Accordingly, on the internal line terminal DKT 1 , processes from making an outgoing call to the external telephone terminal TT 1  to setting transfer to the internal line terminal DKTm can be performed at once. Therefore, with a small number of operations, a returned incoming call from the external telephone terminal TT 1  can be received on the internal line terminal DKTm which is registered for transfer, whereby responses to individual callers can be efficiently made.  
      In addition, in the first embodiment, optimal incoming call control can be performed according to a registered called party&#39;s dial number in the central control unit  14  of the main apparatus  1 . That is, when an outgoing telephone number included in an incoming call matches any of called parties&#39; dial numbers stored in the outgoing history database  151 , incoming call control can be performed on the internal line terminal DKTm which is registered for incoming call transfer. When it does not match, incoming call control is performed on a destination of an incoming call specified by a usual function setting or the like.  
     SECOND EMBODIMENT  
       FIG. 7  is a flowchart, according to a second embodiment of the present invention, showing the procedures of a control process of the central control unit  14  performed when the internal line terminal DKTm which is the destination of transfer of an incoming call cannot receive the call.  
      It is assumed that an outgoing call is made from the external telephone terminal TT 1  and in response thereto an incoming call including an outgoing telephone number arrives on the main apparatus  1  from the public network PNW. In this case, the central control unit  14  extracts the outgoing telephone number from the incoming call and makes a determination on the internal line terminal DKTm which is associated with the outgoing telephone number and which is the destination of the incoming call on the basis of the table in the outgoing history database  151 .  
      Here, it is assumed that the internal line terminal DKTm is busy. Then, the central control unit  14  proceeds from block ST 7   a  to block ST 7   b  where the central control unit  14  transmits, with reference to the table in the outgoing history database  151 , incoming call data to the internal line terminal DKT 1  which is a source of transfer of the incoming call and allows the internal line terminal DKT 1  to generate an incoming call alarm.  
      On the other hand, if the internal line terminal DKTm which is the destination of transfer of the incoming call is not busy but is not answered within a certain period of time, the central control unit  14  proceeds from block ST 7   c  to block ST 7   b  where the central control unit  14  transmits, with reference to the table in the outgoing history database  151 , incoming call data to the internal line terminal DKT 1  which is the source of transfer of the incoming call and allows the internal line terminal DKT 1  to generate an incoming call alarm.  
      If, in the block ST 7   c , the internal line terminal DKTm is answered within the certain period of time, the central control unit  14  establishes a communication link between the internal line terminal DKTm and the external telephone terminal TT 1  (block ST 7   d ).  
      As described above, according to the second embodiment, when, for example, the user on the internal line terminal DKT 1  is returned to a location where the internal line terminal DKT 1  is installed from a location where the internal line terminal DKTm is installed, the user can answer a returned incoming call from the external telephone terminal TT 1  on the internal line terminal DKT 1 .  
     OTHER EMBODIMENTS  
      The present invention is not limited to the foregoing embodiments. For example, in the first and second embodiments, an example is described in which, when the destination of an outgoing call is busy and cannot answer the call, an incoming call reservation key on an internal line terminal which is a source of the outgoing call is pressed, whereby registration is made to transfer an incoming call to another internal line terminal. The present invention is, however, not limited thereto, and it is also possible that a call is made to the destination of the outgoing call and after the call is finished an incoming call reservation key on an internal line terminal which is a source of the outgoing call is pressed to make registration to transfer an incoming call to another internal line terminal.  
      Moreover, although in the foregoing embodiments an example in which an internal line terminal is specified as the destination of transfer of an incoming call, is described, it is also possible to specify a telephone terminal on a public network as the destination of transfer of an incoming call. By doing so, in the case in which the destination of transfer of an incoming call is a mobile phone, whatever the location, responses to individual callers can be made.  
      For the type (a PBX may be used instead of the main apparatus) and configuration of a telephone exchange apparatus, the type of an internal line terminal, the registration procedures for the destination of transfer of an incoming call, the procedures of controlling a returned incoming call, and the like, various modifications can be made without departing from the scope of the present invention.  
      While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.