Abstract:
The invention discloses a call pickup method for a communication network system comprising a first terminal and a second terminal. The method comprise the steps of: (a) setting a common group extension in each of the first terminal and the second terminal; (b) transmitting a pickup request message via the common group extension from the second terminal while the first terminal is receiving an incoming call from a third terminal; (c) receiving the pickup request message from the second terminal via the common group extension at the first terminal; (d) transmitting a transfer message related to the pickup request message from the first terminal to the third terminal; (e) transmitting an invitation message from the third terminal to the second terminal; and (f) establishing the incoming call between the second terminal and the third terminal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a call pickup method, and more particularly, to a call pickup method for a communication network system. 
         [0003]    2. Description of the Prior Art 
         [0004]    Call pickup is a very useful function for a small and commercial private branch exchange (PBX) system. In detail, in a work group or in the same office, the call pickup is a function that allows one to answer a phone call to certain telephone used by someone else via said one&#39;s own telephone. 
         [0005]    Generally, the function of call pickup should be performed in a PBX system. In other words, a telephone does not have the function of call pickup without the support of the PBX server. In early days, when a user wanted to pick up an incoming call to a specific phone, the user had to dial the extension number of the phone. However, the user is required to memorize the extension number, and it is inconvenient. Currently, through another method, what the user has to do is to dial an access key merely. For example, the user just presses “ ” the button to pick up the incoming call without memorizing any extension number. 
         [0006]    Nevertheless, only complicated settings are accomplished in the PBX server, the above two conventional call pickup methods can be performed. Furthermore, different PBX servers have different settings, so it is impractical and confusing for users. 
         [0007]    From the view of this problem, the main scope of the invention is to provide a call pickup method for a communication network system. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, an aspect of the present invention is to provide a call pickup method for a communication network system comprising a first terminal and a second terminal. The call pickup method comprises the following steps according to one embodiment of the invention. 
         [0009]    First of all, a common group extension is set for the first terminal and the second terminal in each of the first terminal and the second terminal. A pickup request message from the second terminal is transmitted via the common group extension while the first terminal is receiving an incoming call from a third terminal. Then the pickup request message from the second terminal is received via the common group extension at the first terminal. Subsequently, a transfer message related to the pickup request message is transmitted from the first terminal to the third terminal. Next, an invitation message is transmitted from the third terminal to the second terminal. Afterwards, the incoming call is established between the second terminal and the third terminal to accomplish the purpose of call pickup. 
         [0010]    The other aspect of the present invention is to provide a communication network system. According to one embodiment of the invention, the communication network system comprises a server, a first terminal, and a second terminal. A common group extension, for the first terminal and the second terminal, is set in each of the first terminal and the second terminal. Besides, the first terminal and the second terminal can communicate with each other via the server. 
         [0011]    A pickup request message from the second terminal is transmitted via the common group extension to the first terminal while the first terminal is receiving an incoming call from a third terminal. Subsequently, the pickup request message from the second terminal is received via the common group extension at the first terminal. Then, a transfer message related to the pickup request message is transmitted from the first terminal to the third terminal. Next, an invitation message is transmitted from the third terminal to the second terminal. Afterwards, the incoming call is established between the second terminal and the third terminal to accomplish the purpose of call pickup. 
         [0012]    The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
         [0013]      FIG. 1  illustrates a function block diagram of a communication network system according to one embodiment of the invention. 
           [0014]      FIG. 2  illustrates a flowing path of signals among a caller, a callee, and a pickupper according to one embodiment of the invention. 
           [0015]      FIG. 3  illustrates a flow chart of a call pickup method according to another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Please refer to  FIG. 1 .  FIG. 1  illustrates a function block diagram of a communication network system  1  according to one embodiment of the invention. 
         [0017]    As shown in  FIG. 1 , the communication network system  1  comprises a server  10 , a first terminal  12 , a second terminal  14 , and a fourth terminal  16 . In practice, the first terminal  12 , the second terminal  14 , and the fourth terminal  16  communicate with each other via the server  10  through a local area network (LAN). Moreover, the network is not limited to LAN. In practice applications, the communication system  1  comprises a PBX server, and a session initiation protocol (SIP) is applied to the communication network system  1 . 
         [0018]    In the communication network system  1 , the first terminal  12 , the second terminal  14 , and the fourth terminal  16  are arranged into a group, and common group extensions ( 120 ,  140 , and  160 ) are set in the terminals ( 12 ,  14 , and  16 ) respectively. In addition to the common group extensions, the first terminal  12 , the second terminal  14 , and the fourth terminal  16  have their own extension numbers ( 122 ,  142 , and  162 ). For example, although a third terminal  20  is set outside the communication network system  1 , it still can selectively dial the extension numbers ( 122 ,  142 , and  162 ) of the terminals ( 12 ,  14 , and  16 ) in the communication network system  1  to communicate via a public switched telephone network (PSTN). 
         [0019]    It should be explained that the extension numbers ( 122 ,  142 , and  162 ) of the first terminal  12 , the second terminal  14 , and the fourth terminal  16  are different to each other; however, the common group extensions ( 120 ,  140 , and  160 ) of the three terminals are identical. Additionally, the first group extension  120 , the second extension  140 , and the fourth group extension  160  are standard for the PBX server. That is to say, the first terminal  12 , the second terminal  14 , and the fourth terminal  16  need not extra support of the PBX server. 
         [0020]    Please refer to  FIG. 1  together with  FIG. 2 .  FIG. 2  illustrates a flowing path of signals among a caller, a callee, and a pickupper according to one embodiment of the invention. In the embodiment, the third terminal  20  represents the caller; the first terminal  12  represents the callee; the second terminal  14  represents the pickupper. In order to further understand the concept of the invention, examples in the following are described in detail. 
         [0021]    While the first terminal  12  receives an incoming call from the third terminal  20 , the third terminal  20  transmits a message “INVITE # 1 ” to the first terminal  12 . Then the first terminal  12  transmits a message “RING # 1 ” to the third terminal  20  and generates a ring message simultaneously. At the same time, dependent on a user U 2  of the second terminal  14 , a pickup request message (as INVITE # 2  shown in  FIG. 2 ) can be transmitted to the first terminal  12  via the common group extension  140 . 
         [0022]    For example, the second terminal  14  can transmit the pickup request message after the first terminal  12  idles for a first predetermined time or after the first terminal  12  rings for a second predetermined time. The first predetermined time represents the passed time since the user U 1  of the first terminal  12  ends the last call, e.g. 10 seconds. During the first predetermined time, if the user U 1  does not leave the first terminal  12 , it can not be allowed that the pickup request message is transmitted to the first terminal  12  via the second group extension  140  by the user U 2  of the second terminal  14  in order not to disturb the user U 1  to answer the incoming call. It is noted that the first predetermined time and the second predetermined time are designed according to practical demands. 
         [0023]    After the second terminal  14  transmits the pickup request message to the first terminal  12 , the pickup request message from the second terminal  14  is received via the common group extension  120  at the first terminal  12 . Because the second terminal  14  transmits the pickup request message to the first terminal  12  via the common group extension  140 , the first terminal  12  can start a call pickup procedure automatically by recognizing that the second terminal  14  asks for the call pickup. 
         [0024]    In one embodiment, the pickup request message comprises first identification information. In practice, the first identification information can be in a package header of the pickup request message. After the pickup request message from the second terminal  14  is received, the first terminal  12  transmits a transfer message (as “REFER” shown in  FIG. 2 ) comprising the first identification information to the third terminal  20 . 
         [0025]    After the transfer message from the first terminal  12  is received, the third terminal  20  transmits a message “OK # 1 ” to the first terminal  12 , indicating that the second terminal  14  is authorized to pick up the incoming call. Besides, after receiving the message “OK # 1 ”, the first terminal  12  terminates the ring message. Subsequently, the third terminal  20  transmits an invitation message (as INVITE # 3  shown in  FIG. 2 ) to the second terminal  14 . 
         [0026]    It is noted that after the invitation message “INVITE # 3 ” is transmitted to the second terminal  14 , the second terminal  14  further judges if the second identification information corresponds to the first identification information or not. If YES, the second terminal  14  transmits a “CANCEL” message to the first terminal  12  and asks the first terminal  12  to be in an idle state. Afterwards, the second terminal  14  transmits a message “RING # 2 ” to the third terminal  20 . 
         [0027]    After receiving the message “RING # 2 ” from the second terminal  14 , the third terminal  20  transmits a message “OK # 2 ” to the second terminal  14 . Subsequently, the second terminal  14  transmits a message “ACK” to the third terminal  20  in order to establish the incoming call between the second terminal  14  and the third terminal  20 . 
         [0028]    It is noted that if the third terminal  20  terminates the incoming call or a user U 3  of the fourth terminal  16  of the communication network system  1  picks up the incoming call via the common group extension  160 , the second terminal  14  can be controlled to be in an idle state. 
         [0029]    Please refer to  FIG. 3 .  FIG. 3  illustrates a flow chart of a call pickup method according to another embodiment of the invention. The call pickup method is suitable for a communication network system comprising a first terminal and a second terminal. 
         [0030]    First of all, step S 100  is performed and a common group extension is set, for the first terminal and the second terminal, in each of the first terminal and the second terminal. The common group extension is shared by the first terminal and the second terminal. 
         [0031]    When the first terminal receives an incoming call from a third terminal, step S 102  is performed to transmit a pickup request message from the second terminal via the common group extension. It is remarkable that in step S 102 , the second terminal transmits the pickup request message after the first terminal idles for a first predetermined time or after the first terminal rings for a second predetermined time. 
         [0032]    Subsequently, S 104  is performed to receive the pickup request message from the second terminal via the common group extension at the first terminal. Subsequently, the step S 106  is performed to transmit a transfer message related to the pickup request message from the first terminal to the third terminal. 
         [0033]    In one embodiment, the pickup request comprises first identification information, and a transfer message comprising the first identification is transmitted to the third terminal in step S 106 . Additionally, a ring message of the first terminal can be terminated by the method after the transfer message is transmitted. 
         [0034]    Next, step S 108  is performed to transmit an invitation message from the third terminal to the second terminal. For the mentioned first identification information, the invitation message comprising second identification information is transmitted to the second terminal. Additionally, the first terminal can be returned to an idle state by the method after the invitation message is transmitted. 
         [0035]    Afterwards, step S 110  is performed to judge if the second identification information corresponds to the first identification information or not. If YES in step S 110 , the step S 112  is performed to establish the incoming call between the second terminal and the third terminal. If NO in step S 110 , the method returns to step S 102 . 
         [0036]    To sum up, the call pickup method of the invention is to set a common group extension for a terminal group in a communication network system. Thus, the group can have the function of call pickup. Because the mentioned group extension is standard for a PBX server, the call pickup method of the invention needs not extra support or complicated settings of the PBX server. Additionally, another advantage of the invention is that a user can pick up the incoming call to some phone without remembering the extension number of the phone. 
         [0037]    With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.