Patent Publication Number: US-2005119021-A1

Title: Telephone apparatus and method for call transfer function

Description:
BACKGROUND OF THE INVENTION  
      This application claims the priority of Korean Patent Application No. 2003-85831, filed on Nov. 28, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.  
      1. Field of the Invention  
      The present invention relates to a telephone call transfer service, and more particularly, to a telephone apparatus with a call transfer function permitting a wired or wireless telephone subscriber to change a call forwarding telephone number using a telephone located at a remote location and a method therefor.  
      2. Description of the Related Art  
       FIG. 3  is a view for describing a call transfer method between a wired telephone and a wireless telephone according to a conventional technique. When a user stays at home, he/she sets a wired telephone  31  as a call receiver, and when he or she goes out, he/she sets a wireless telephone  32  as a call receiver. Thus, when an external telephone establishes a call with the wired telephone  31  in the state where a call transfer function is activated in the wired telephone  31 , a switching system  33  calls the wireless telephone  32  automatically and permits the external telephone to establish a call with the wireless telephone  32 .  
      According to the conventional technique, a user could set a call transfer only through a telephone (wired telephone  31  of  FIG. 3 ) with a call transfer function. Therefore, if the user does not set a call forwarding to the wireless phone using the wired telephone (for example, home telephone) when going out, he/she cannot receive any in-progress telephone call established with the wired telephone.  
     SUMMARY OF THE INVENTION  
      The present invention provides a telephone apparatus with a call transfer function permitting a user to change a call forwarding telephone number using a telephone located at a remote location, and a method therefor.  
      According to an aspect of the present invention, there is provided a telephone apparatus comprising: a memory, which stores a call forwarding telephone number and a user password; a DTMF identifier, which identifies a number received from an external telephone; a controller, which requires a caller to input a password, determines whether a password received from the caller is the same as that stored in the memory, receives a call forwarding telephone number from the caller, and stores the call forwarding telephone number in the memory; and a call transfer unit, which outputs a call transfer request signal and the call forwarding telephone number stored in the memory, to a switching system.  
      According to another aspect of the present invention, there is provided a call transfer method comprising: receiving a call from an external telephone; determining whether a caller of the external telephone is a valid user; receiving a call forwarding telephone number from the caller; and outputting a call transfer request signal and the received call forwarding telephone number to a switching system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:  
       FIG. 1  is a block diagram of a telephone system according to an embodiment of the present invention;  
       FIG. 2  is a flowchart illustrating a call transfer method according to an embodiment of the present invention; and  
       FIG. 3  is a view for describing a call transfer method between a wired telephone and a wireless telephone, according to a conventional technique. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Hereinafter, embodiments of the present invention will be described in detail with reference to the appended drawings.  
       FIG. 1  is a block diagram of a telephone system according to an embodiment of the present invention. Referring to  FIG. 1 , the telephone system includes a first telephone  10  with a call transfer function and a second telephone  20  as a call forwarding telephone. If an external caller establishes a call with the first telephone  10  in the state where a call forwarding to the second telephone  20  is set by the first telephone  10 , a switching system  30  automatically transfers the call to the second telephone  20 . Also, according to this embodiment, it is possible to transfer a call received through the first telephone  10  to the second telephone  20  or to an arbitrary different telephone (not shown) using a third telephone  40  located at a remote location.  
      Here, the first, second and third telephones  10 ,  20  and  40  are telephones allowing wired or wireless communication. Also, it is assumed in the above-description regarding  FIG. 1  that only the first telephone  10  has the call transfer function, however, only the second telephone  20  or both the first and second telephones  10  and  20  can have the call transfer function.  
      Hereinafter, a call transfer method between the first telephone  10  and the second telephone  20  will be described. The first telephone  10  with a call transfer function includes a memory  13  which stores a telephone number of a second telephone  20  as a call forwarding telephone, a dial unit  11  through which telephone numbers are input and functions are set, a controller  12  which receives a command signal such as a call transfer command, a telephone number, etc. from the dial unit  11  and reads contents stored in the memory  13 , and a call transfer unit  14  which outputs a call transfer signal to a switching system  30  under the control of the controller  12 .  
      Here, the call transfer signal is a signal defined in a telephone company and can be composed of “numeral or character (* or #) for call transfer+telephone number of a call forwarding telephone”. For example, the call transfer signal is *88+ telephone number+ * and a call transfer release signal is #88*.  
      Accordingly, if a user sets call transfer settings through the dial unit  11 , the controller  12  sets a call transfer mode, reads a telephone number of a call forwarding telephone (for example, second telephone  20 ) stored in the memory  13  and outputs the read telephone number to the call transfer unit  14 . Then, the call transfer unit  14  transmits a call transfer signal to the switching system  30 . If a caller establishes a call with the first telephone  10 , the switching system  30  allows the caller to establish a call with the second telephone  20 .  
      Hereinafter, a call transfer system in which a call transfer is performed by a different telephone (referred to as a third telephone  40 ) will be described.  
      Referring to  FIG. 1 , in order to perform a call transfer using an arbitrary third telephone  40  located at a remote location, a first telephone  10  includes a memory  13  which stores a telephone number of a call forwarding telephone and a user password, a controller  12  which requires a caller to input a password if the first telephone  10  receives a call under circumstances that an automatic call transfer function is set, determines whether the password input from the caller is the same as that stored in the memory, receives a call forwarding telephone number from the caller and stores the received telephone number in the memory  13 , and a call transfer unit  14  which outputs a call transfer request signal with the call forwarding telephone number stored in the memory  13  to a switching system  30 . A DTMF identifier  16  identifies a telephone number received from the external third telephone  40  and provides the telephone number to the controller  12 .  
       FIG. 2  is a flowchart illustrating a call transfer method in which a call transfer is performed in the first telephone  10  through a call from a third telephone  40 , according to an embodiment of the present invention.  
      Referring to  FIG. 2 , when a caller establishes a call with the first telephone  10  using the third telephone  40  in step  22 , the first telephone  10  with an automatic call transfer function activates its automatic call transfer function the first telephone  10  is not answered within a predetermined time. Meanwhile, a user can set an operation state of the first telephone  10  in advance so that a call forwarding telephone number can be changed.  
      If a mode of changing a call forwarding telephone number is activated using the third telephone  40 , the first telephone  10  requests the caller to input a password in step  24 . Requesting the password is to check whether or not the caller is a valid user of the first telephone  10 . If such a user authentication is not performed, an arbitrary third party may set call forwarding to a different telephone for a valid user&#39;s first telephone.  
      If the password input by the third telephone  30  is the same as that stored in the first telephone  10  in step  25 , the first telephone  10  requires the caller to input a telephone number to be used as a call forwarding telephone number. If the user presses numerals corresponding to a call forwarding telephone number and an input terminating indicator (for example, #) using the third telephone  40 , the first telephone  10  identifies the telephone number input from the third telephone  40  and stores the telephone number in the memory  13  in step  26 . Identifying the telephone number can be performed by the switching system  30  or the DTMF identifier  16  of the first telephone  10 . The call forwarding telephone may be the second telephone  20  or the third telephone  40  or may be a different telephone.  
      The call transfer unit  14  of the first telephone  10  creates a call transfer request signal and a call transfer signal (for example, *88+telephone number+*) based on the received call forwarding telephone number, and automatically transmits the call transfer signal to the switching system  30  so that the switching system  30  permits the first telephone  10  to perform a call forwarding to the call forwarding telephone when a call transfer request is issued, in step  27 .  
      The memory  13  of the first telephone  10  stores a password for identifying a caller when a call transfer request is received from the third telephone  40  and stores a message to be used for requiring a password or a telephone number.  
      A telephone which requests a call transfer at a remote location may be the second telephone  20 . Also, when the second telephone  20  requests an automatic call forwarding to the second telephone  20 , to the first telephone  10 , a telephone number pre-stored in the memory  13  can be used. Also, when the third telephone  30  requests an automatic call forwarding to the second telephone  20 , to the first telephone  10 , a telephone number pre-stored in the memory  13  can be used. Meanwhile, if the first telephone  10  has an Automatic Number Identification (AN I) function, that is, if the first telephone  10  can identify the telephone number of the third telephone  30 , the first telephone  10  can perform the automatic call forwarding to the third telephone  30  using a telephone number stored therein without receiving a separate telephone number.  
      In this disclosure, a call transfer for the first telephone  10  using the third telephone  40  has been illustrated. However, it is also possible that the user performs a call forwarding to a different telephone number for the second telephone  20  which is basically set to perform a call forwarding function with the first telephone  10 , using the third telephone  40 . That is, if the user sets an automatic call forwarding to the second telephone  20  for the first telephone  10 , the third telephone  40  establishes an in-progress telephone call with the second telephone  20  when the third telephone  40  calls the first telephone  10 . At this time, the third telephone  40  can perform a call forwarding to an arbitrary different telephone through the second telephone  20  instead of the first telephone  10 .  
      The present invention may be embodied as a program stored on a computer readable medium that can be run on a general computer. Here, the computer readable medium includes but is not limited to storage media such as magnetic storage media (e.g., ROM&#39;s, floppy disks, hard disks, etc.), optically readable media (e.g., CD-ROMs, DVDs, etc.), and carrier waves (e.g., transmission over the Internet). The present invention may also be embodied as a computer readable program code unit stored on a computer readable medium, for causing a number of computer systems connected via a network to affect distributed processing.  
      As described above, according to the conventional technique, a call transfer is performed by activating a call transfer function in advance for a telephone with the call transfer function. However, according to the present invention, by allowing a user to perform a call forwarding to a desired telephone number using an arbitrary telephone, a subscriber using a call transfer function can freely change a call forwarding telephone number using an arbitrary telephone at any location, so that the subscriber can receive all calls through the arbitrary telephone at any location.  
      Also, according to the conventional technique, when a telephone with a call transfer function receives a call, a call forwarding to a predetermined call forwarding telephone number is performed after the telephone rings a predetermined number of times. However, according to one embodiment of the present invention, a subscriber can set or change a call forwarding telephone number selectively and conveniently regardless of his/her location.  
      While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.