Patent Publication Number: US-2007121831-A1

Title: Apparatus and method for making call connection when parties try to sumultaneously call each other

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
      This application claims the benefit under 35 U.S.C. § 119(a) of a Korean Patent Application filed in the Korean Intellectual Property Office on Aug. 10, 2005 and assigned Ser. No. 2005-73234, the entire disclosure of which is hereby incorporated by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an apparatus and method for rejecting a call connection request. More particularly, the present invention relates to an apparatus and method for, when two parties try to call each other simultaneously, rejecting a call connection request from one of the parties in a predetermined rule and making a call connection between the two parties.  
      2. Description of the Related Art  
      In a call connection process over an existing wired/wireless telephone network, a caller dials a number of a called party and then the called number is passed to a local switch serving the called party via a local switch serving the caller. If the called party is not busy, a call connection signal is sent to the called party. When the called party answers the call, the call is set up and a conversation starts between the caller and the called party. If the called party is busy, a busy signal is sent to the caller to thereby indicate that the called party is not available.  
       FIG. 1  illustrates a configuration of a typical wired/wireless telephone network. Referring to  FIG. 1 , the typical wired/wireless telephone network includes Public Switched Telephone Network (PTSN) switches  116  and  118  for relaying calls to phones  100  and  102 , respectively, and Mobile Switching Centers (MSCs)  112  and  114  for relaying calls between mobile terminals  104  and  106  via antennas  108  and  110 . When the phones  100  and  102  or the mobile terminals  104  and  106  request a call connection, the PTSN switches  116  and  118  or the MSCs  112  and  114  communicate with the PSTN switch or the MSC of the called party.  
      When the phone  100  requests a call connection to the mobile terminal  106 , the PTSN switch  116  receives the call connection request signal from the phone  100  and determines whether the mobile terminal  106  is available through the MSC  114 . If the mobile terminal  106  is busy, the PTSN switch  116  sends busy tones to the phone  100 . If the mobile terminal  106  is available, the PTSN switch  116  sends a call connection signal to the mobile terminal  106  through the MSC  114 .  
      Since a determination is made as to whether a call connection can be set up by checking whether the called party is busy, if the called party is trying to call the caller at the same time, the call cannot be connected in a conventional call connection process over the wired/wireless telephone network. That is, when two terminals request a call connection to each other simultaneously, the call connection is not established between the two terminals.  
      Due to the development and proliferation of mobile terminals and phones, mobile terminals and phones have become a necessity. Particularly, a resulting increase in a number of calls often causes call drops in mobile terminals and phones. Accordingly, there is a need for an improved apparatus and method for establishing a call connection between two parties when the two parties make calls to each other simultaneously.  
     SUMMARY OF THE INVENTION  
      An aspect of exemplary embodiments of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide an apparatus and method for establishing a call connection between two parties when the two parties make calls to each other simultaneously.  
      Another aspect of exemplary embodiments of the present invention is to provide an apparatus and method for, when two parties try to call each other simultaneously, rejecting a call connection request from one of the parties in a predetermined rule and making a call connection between the two parties.  
      The above aspects are achieved by providing an apparatus and method for establishing a call connection when both parties try to simultaneously call each other.  
      According to one aspect of exemplary embodiments of the present invention, in a simultaneous call connection apparatus, a simultaneous signal comparator determines, upon receipt of a call connection request, whether a calling terminal and a called terminal are trying to call each other simultaneously, and if the calling terminal and the called terminal are busy when calling each other simultaneously, requests rejection of a call connection request from one of the calling terminal and the called terminal and setup of a call connection between the calling terminal and the called terminal. A switch rejects the call connection request from the one of the calling terminal and the called terminal and establishes the call connection between the calling terminal and the called terminal according to the request of the simultaneous signal comparator.  
      According to another aspect of exemplary embodiments of the present invention, in a simultaneous call connection method in a simultaneous call connection apparatus, upon receipt of a call connection request in a simultaneous call mode, information about a called terminal is verified. A determination is made as to whether the called terminal is requesting a call connection to a calling terminal simultaneously. If the calling terminal and the called terminal are busy when requesting the call connection to each other simultaneously, the call connection request from the called terminal is rejected, and a connection command is sent to a simultaneous call connection apparatus which has sent the call connection request from the calling terminal.  
      According to a further aspect of exemplary embodiments of the present invention, in a simultaneous call connection method in a simultaneous call connection apparatus, upon receipt of a call connection request in a simultaneous call mode, information about a called terminal is verified. A determination is made as to whether the called terminal is requesting a call connection to a calling terminal simultaneously in the simultaneous call mode by comparing the information about the called terminal and stored call connection information. If the calling terminal and the called terminal are busy in requesting the call connection to each other simultaneously, a terminal whose call connection request is rejected is selected in a method. If the simultaneous call connection apparatus includes a non-selected terminal, a simultaneous call connection apparatus including the selected terminal is requested to reject the call connection request from the selected terminal. The call connection is then established. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of certain exemplary embodiments of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings in which:  
       FIG. 1  illustrates a configuration of a typical wired/wireless telephone network;  
       FIG. 2  illustrates a configuration of a simultaneous call connection apparatus according to an exemplary embodiment of the present invention;  
       FIG. 3  is a diagram illustrating a signal flow for a simultaneous call connection operation in a communication system supporting a call connection for simultaneous call connection requests according to an exemplary embodiment of the present invention;  
       FIG. 4  is a diagram illustrating a signal flow for a simultaneous call connection operation in the communication system supporting a call connection for simultaneous call connection requests according to an exemplary embodiment of the present invention; and  
       FIG. 5  is a flowchart illustrating a simultaneous call connection operation in the simultaneous call connection apparatus when a call connection request is received in a simultaneous call mode according to an exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
      The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of exemplary embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.  
      Embodiments of the present invention are intended to provide an apparatus and method for establishing a call connection between two parties when the two parties make calls to each other simultaneously.  
      Before describing the present invention, terms used herein are defined as follows. “Simultaneous call connection” is a call connection established between both parties when the two parties make calls to each other simultaneously, “simultaneous call connection apparatus” is an apparatus for establishing the simultaneous call connection, and “simultaneous call mode” is a mode set to establish the simultaneous call connection.  
       FIG. 2  illustrates the configuration of a simultaneous call connection apparatus according to an exemplary embodiment of the present invention.  
      Referring to  FIG. 2 , the simultaneous call connection apparatus includes phones  200  and  202 , mobile terminals  204  and  206 , PTSN switches  216  and  218 , antennas  208  and  210 , MSCs  212  and  214 , and simultaneous signal comparators  220 ,  222 ,  224  and  226 .  
      When the PTSN switches  216  and  218  or the MSCs  212  and  214  receive a call connection request in a simultaneous call mode from the phones  200  and  202  or the mobile terminals  204  and  206 , the PTSN switches  216  and  218  or the MSCs  212  and  214  provide the call connection request to a corresponding simultaneous signal comparator, reject a call connection request from the caller or the called party upon request of the simultaneous signal comparator, and then establish a call connection between the caller and the called party.  
      Upon receipt of a call connection request signal from a PTSN switch or an MSC, each of the simultaneous signal comparators  220 ,  222 ,  224  and  226  determines whether a caller and a called party associated with the call connection request signal are attempting to call each other, that is, in a simultaneous busy state. If the caller and called party are busy simultaneously, the simultaneous signal comparator requests the PTSN switch or the MSC to reject a call connection request from the caller or the called party and makes a call connection between the caller and the called party. A detailed description of a call connection in the case of simultaneous call connection requests will be given later with reference to  FIGS. 3, 4  and  5 .  
      In an exemplary implementation, the PTSN switches  216  and  218  or the MSCs  212  and  214  may be configured to perform the functionality of the simultaneous signal comparators  220 ,  222 ,  224  and  226 , while the simultaneous signal comparators  220 ,  222 ,  224  and  226  are shown separately from the PTSN switches  216  and  218  and the MSCs  212  and  214 , for better understanding of the functionality of the simultaneous signal comparators  220  to  226 . In other words, the simultaneous signal comparators  220 ,  222 ,  224  and  226  can be incorporated into the PTSN switches  216  and  218  or the MSCs  212  and  214  or separately configured from the PTSN switches  216  and  218  and the MSCs  212  and  214 .  
       FIG. 3  is a diagram illustrating a signal flow for a simultaneous call connection operation in a communication system supporting a call connection for simultaneous call connection requests according to an exemplary embodiment of the present invention.  
      In  FIG. 3 , two terminals are attempting to make calls to each other simultaneously, in which one of the terminals makes a call in a simultaneous call mode. Referring to  FIG. 3 , when a first terminal  302  requests a first simultaneous signal comparator  306  to make a call connection to a second terminal  312  in the simultaneous call mode through a first switch  304  in step  314 , the first simultaneous signal comparator  306  stores call connection information, generates a call connection request signal containing the phone number of the called second terminal  312 , and sends the call connection request signal to a second simultaneous signal comparator  308  serving the second terminal  312 .  
      Without knowing the call attempt from the first terminal  302 , the second terminal  312  attempts to call the first terminal  302  through a second switch  310  in step  316 . The second switch  310  attempts the call to the first switch  304  in step  318 , and at the same time, the second terminal  312  is transitioned to a busy state.  
      Meanwhile, the second simultaneous signal comparator  308  searches for call connection information corresponding to the called number set in the call connection request signal received in step  320 . In the absence of the call connection information, the second simultaneous signal comparator  308  requests the second switch  310  to check the state of the called second terminal  312  in step  322  and receives a response for the state check request from the second switch  310  in step  324 . If the response indicates the second terminal  312  is attempting to call the first terminal  302 , the second simultaneous signal comparator  308  sends a connection command to the first simultaneous signal comparator  306  in step  326 . In step  330 , the second simultaneous signal comparator  308  sends a connection hold request to the second switch  310 .  
      The first simultaneous signal comparator  306  forwards the connection command to the first switch  304  in step  328 . In step  332 , the second simultaneous signal comparator  310  rejects the call connection request from the second terminal  312  and the second switch  310  sends a connection hold signal to the second terminal  312 .  
      Upon receipt of the connection command, the first switch  304  establishes a call connection with the second switch  310  in step  334  and thus, the first terminal  302  makes a conversation with the second terminal  312  in step  336 .  
       FIG. 4  is a diagram illustrating a signal flow for a simultaneous call connection operation in the communication system supporting a call connection for simultaneous call connection requests according to an exemplary embodiment of the present invention.  
      In the illustrated case of  FIG. 4 , two terminals try to call each other simultaneously in the simultaneous call mode. Referring to  FIG. 4 , when a first terminal  402  requests a first simultaneous signal comparator  406  to make a call connection to a second terminal  412  through a first switch  404  in the simultaneous call mode in step  414 , the first simultaneous signal comparator  406  stores call connection information and sends a call connection request signal including the phone number of the called second terminal  412  to a second simultaneous signal comparator  408  serving the second terminal  412  in step  418 .  
      Without knowing the call attempt from the first terminal  402 , the second terminal  412  attempts to call the first terminal  402  through a second switch  410  in the simultaneous call mode in step  416 . The second simultaneous signal comparator  408  stores call connection information associated with the call attempt and sends a call connection request signal including the phone number of the called first terminal  402  to the first simultaneous signal comparator  406  in step  420 .  
      Meanwhile, the second simultaneous signal comparator  408  searches for call connection information corresponding to the called number set in the call connection request signal received in step  418 . In the presence of the call connection information, the second simultaneous signal comparator  408  recognizes that the first and second terminals  402  and  412  have requested the call connection simultaneously and selects a terminal whose call connection request will be rejected. If the call connection request from the second terminal  412  is rejected, the second simultaneous signal comparator  408  receives a connection hold request from the first simultaneous signal comparator  406  in step  422  and forwards the connection hold request to the second switch  410  in step  426 .  
      The first simultaneous signal comparator  406  searches for call connection information corresponding to the called number set in the call connection request signal received in step  420 . In the presence of the call connection information, the first simultaneous signal comparator  406  recognizes that the first and second terminals  402  and  412  have requested the call connection simultaneously and selects a terminal whose call connection request will be rejected. If the call connection request from the second terminal  412  is rejected, the first simultaneous signal comparator  406  sends the connection hold request to the second simultaneous signal comparator  408  in step  422  and sends a connection command to the first switch  404  in step  424 . In step  428 , the second simultaneous signal comparator  408  rejects the call connection request from the second terminal  412  and the second switch  410  sends a connection hold signal to the second terminal  412 .  
      Upon receipt of the connection command, the first switch  404  establishes a call connection with the second switch  410  in step  430  and thus, the first terminal  402  converses with the second terminal  412  in step  432 .  
       FIG. 5  is a flowchart illustrating a simultaneous call connection operation in the simultaneous call connection apparatus illustrated in  FIG. 2  when a call connection request is received in the simultaneous call mode according to an exemplary embodiment of the present invention.  
      Referring to  FIG. 5 , upon receipt of a call connection request from a calling terminal in step  500 , the simultaneous call connection apparatus checks a called number in step  502  and determines whether a called terminal is attempting a call by searching stored call connection information in step  504 .  
      If the called terminal is attempting to call the calling terminal, the simultaneous call connection apparatus determines whether the calling terminal and the called terminal associated with the call connection request are requesting call connection to each other simultaneously by comparing the call connection request signal with the stored call connection information in step  506 . If they are not attempting to call each other at the same time, the simultaneous call connection apparatus sends a call unavailable signal to the calling terminal in step  520 .  
      On the other hand, if both the calling terminal and the called terminal are trying to call each other simultaneously, the simultaneous call connection apparatus selects one of the terminals of which the call connection request is to be rejected in a predetermined method in step  508 . The predetermined method can be to select a terminal whose phone number is larger or less than that of the other terminal by comparing the phone numbers of the two terminals partially or wholly.  
      In step  510 , the simultaneous call connection apparatus determines whether the calling terminal and the called terminal belong to different simultaneous call connection apparatuses and the selected terminal belongs to the simultaneous call connection apparatus. If the calling terminal and the called terminal belong to different simultaneous call connection apparatuses and the selected terminal belongs to the simultaneous call connection apparatus, a control operation for simultaneous call connection is carried out in the other simultaneous call connection apparatus.  
      If the simultaneous call connection apparatus includes the calling terminal and the called terminal or does not include the selected terminal, the simultaneous call connection apparatus requests the other simultaneous call connection apparatus to reject the call connection request from the selected terminal and output a connection hold signal to the selected terminal in step  512  and establishes the call connection in step  522 .  
      Meanwhile, if the called terminal is not attempting a call in the simultaneous call mode in step  504 , the simultaneous call connection apparatus determines whether the called terminal is busy in step  514 . If the called terminal is not busy, the simultaneous call connection apparatus establishes the call connection in step  522 .  
      If the called terminal is busy in step  514 , the simultaneous call connection apparatus determines whether the calling terminal and the called terminal are requesting the call connection to each other simultaneously in step  516 . If they are not, the simultaneous call connection apparatus sends the call unavailable signal to the calling terminal in step  520 .  
      If the calling terminal and the called terminal are requesting the call connection to each other simultaneously, the simultaneous call connection apparatus rejects the call connection request from the called terminal and sends the connection hold signal to the called terminal in step  518  and establishes the call connection by sending a connection command to a simultaneous call connection apparatus that has sent the call connection request signal in step  522 .  
      Exemplary embodiments of the present invention can also be embodied as computer-readable codes on a computer-readable recording medium. The computer-readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer-readable recording medium include, but are not limited to, read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, can carrier waves (such as data transmission through the Internet via wired or wireless transmission paths). The computer-readable recording medium can also be distributed over network-coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. Also, functional programs, codes, and code segments for accomplishing the present invention can be easily construed as within the scope of the invention by programmers skilled in the art to which the present invention pertains.  
      As described above, the exemplary embodiments of present invention provides an apparatus and method for, when two parties try to call each other simultaneously, rejecting a call connection request from one of the parties in a predetermined rule and making a call connection between the two parties. Therefore, when phone users attempt to call each other at the same time, a call can be made between the phone users, thus increasing user convenience.  
      While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.