Abstract:
Provided is an apparatus and method for Call Completion to Busy Subscriber (CCBS) service in a mobile communication system. The method includes determining if a MT is in a telephony possibility state, determining if the MT is using the CCBS service, sending a request for a priority of a Mobile Originator (MO) to the MT, transmitting a response to the network apparatus, storing information on a call of the MO in a queue of the network apparatus, and sending a notification of telephony possibility to the MO.

Description:
PRIORITY 
       [0001]    This application claims priority under 35 U.S.C. §119 to an application filed in the Korean Intellectual Property Office on Jul. 31, 2006 and assigned Serial No. 2006-71951, the contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to a mobile communication system, and in particular, to an apparatus and method for applying a priority to a call and sending a notification to a user of a preset high-priority call, in Call Completion to Busy Subscriber (CCBS) service. 
         [0004]    2. Description of the Related Art 
         [0005]    When a Mobile Terminal (MT) is in a Network Determined User Busy (NDUB) state, that is, when the receiver is in communication with other MTs or when a call fails because there is not enough of a communication path for the MT, a CCBS service stores information on the call experiencing the telephony failure in a queue of a network apparatus and after the MT is converted to a telephony possible state (that is, when it is out of the NDUB state), informs a sender that the MT is in the telephony possible state. In other words, the CCBS service is a service for providing to the sender then time when a telephony possibility exists. 
         [0006]      FIG. 1  illustrates a conventional CCBS service procedure. 
         [0007]    Referring to  FIG. 1 , in step  130 , a Mobile Originator (MO)  100  transmits a setup request message (SETUP) and attempts a telephony setup to a MT  120 . In step  140 , a network apparatus  110 , receiving the setup request message transmits a circuit disconnect message (DISCONNECT) to the MO  100  to signal a disconnect. 
         [0008]    In step  150 , the network apparatus  110  transmits to the MO  100  a setup possibility notification message (RECALL) when the MT  120  is out of the NDUB state. In step  160 , the MO  100 , receiving the setup possibility notification message (RECALL), resumes a setup procedure when the MT  120  is in a telephony possibility state. 
         [0009]    The CCBS service is provided using a message format used in a general call setting procedure. For example, specialized values for CCBS are added to a message such as SETUP, DISCONNECT, etc. and are forwarded to the appropriate entity. Networks generally provide a CCBS service in which a queue can be set for a maximum of five calls per user. However, because the number of calls that can be stored in the queue is five, it is impossible to provide a CCBS service for six or more calls. 
         [0010]    The CCBS service is similar with “Call Waiting Supplementary Service”, which is a call waiting service, in that the service informs a MT that another call is generated during a call. However, the call waiting service can allow the MT to check Call Line Identity Presentation (CLIP) information (that is, a sender&#39;s telephone number) and perform selective call conversion, whereas the CCBS service does not have a selective call attempt notification function. 
         [0011]    In other words, there is a drawback that despite a call that a user preferentially desires to receive, a user cannot be provided with a CCBS service based on a priority because of the absence of a procedure to provide this information. 
       SUMMARY OF THE INVENTION 
       [0012]    An aspect of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, an aspect of the present invention is to provide an apparatus and method for a CCBS service, for applying a priority to a specific telephone number in a mobile communication system. 
         [0013]    Another aspect of the present invention is to provide a network apparatus and method for providing notice of a higher-priority call to a mobile terminal when a call having a higher priority than a previously setup call stored in a given queue is setup. 
         [0014]    A further aspect of the present invention is to provide an apparatus and method for providing a high-priority telephone number, thereby receiving a notification of an earlier setup than a low-priority telephone number when a call from the high-priority telephone number is setup. 
         [0015]    According to one aspect of the present invention, there is provided a method for Call Completion to Busy Subscriber (CCBS) service in a mobile communication system. The method includes determining if a Mobile Terminal (MT) is in a telephony possibility state when a network apparatus receives a setup request for the MT from a Mobile Originator (MO); when the MT is not in a telephony possibility state, determining if the MT is in use of CCBS service; when the MT is in use of CCBS service, sending to the MT a request for a priority of the MO; transmitting to the network apparatus by the MT, a response to the request for priority including the priority; storing, by the network apparatus receiving the response, information on a call of the MO in a queue of the network apparatus according to the priority included in the response; and when the MT is in a telephony possibility state, sending, by the network apparatus, a notification of possible calls in a sequence of the call information stored in the queue to the MO. 
         [0016]    According to another aspect of the present invention, there is provided a network apparatus for CCBS service in a mobile communication system. The apparatus includes a priority comparator, a priority control unit, and a controller. The priority comparator determines if a MT that is not in a telephony possibility state is in use of the CCBS service by a control and provision information of the controller. The priority control unit stores call information on an MO in a queue for the CCBS service according to a priority by the control and provision information of the controller. Upon receipt of a setup request for the MT from an MO, the controller controls the priority comparator to determine if the MT is in use of the CCBS service. The controller sends a request for a priority of the MO to the MT. The controller receives and provides a response to the priority control unit. The controller controls the priority control unit to store the call information according to the priority. When the MT is in a telephony possibility state, the controller sends a notification of possible calls in a sequence of the call information stored in the queue to the MO. 
         [0017]    According to a further aspect of the present invention, there is provided a mobile terminal for CCBS service in a mobile communication system. The terminal includes a priority analyzer, a priority comparator, and a controller. The priority analyzer acquires information on a MT by a control and provision information of the controller. The priority comparator decides a priority of the MT on the CCBS service by the control and provision information of the controller. Upon receipt of a request for the priority of the MT from a network apparatus, the controller controls the priority analyzer to provide information on the MT. The controller controls the priority comparator to provide the priority of the MT on the CCBS service. The controller provides a response to the priority request including the received priority. 
         [0018]    According still another aspect of the present invention, there is provided a system for CCBS service in a mobile communication system. The system includes an MO, a network apparatus, and a MT. The MO sends a setup request to communicate with a MT. When the MT is in a telephony impossible state and has a high priority on the CCBS service, the MO receives a notification of preferential possible calls after the MT is converted to a telephony possible state. The network apparatus receives a setup request for the MT from the MO. The network apparatus sends a request for a priority of the MO on the CCBS service to the MT when the MT is in use of the CCBS service. The network apparatus receives the priority as a response. The network apparatus stores information on a call of the MO in a queue for CCBS service according to priority. The network apparatus sends to the MT a notification that the MT is in a telephony possibility state when the MT is in a reception possible state. The MT receives the request for the priority of the MO from the network apparatus and provides the priority as a response. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
           [0020]      FIG. 1  illustrates a conventional CCBS service procedure; 
           [0021]      FIG. 2  illustrates a CCBS service procedure according to an exemplary embodiment of the present invention; 
           [0022]      FIG. 3  is a block diagram of a network apparatus for CCBS service according to an exemplary embodiment of the present invention; 
           [0023]      FIG. 4  is a block diagram of a mobile terminal for CCBS service according to an exemplary embodiment of the present invention; 
           [0024]      FIG. 5  is a flowchart of a procedure of operating a network apparatus for CCBS service according to an exemplary embodiment of the present invention; and 
           [0025]      FIG. 6  is a flowchart of a procedure of operating a mobile terminal for CCBS service according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. 
         [0027]    Information, which represents a priority proposed in the present invention, is applicable to not only a CCBS service but also other supplementary services. 
         [0028]    According to the present invention, in a CCBS service, a mobile terminal sets a priority to a telephone number to be processed preferentially. This is listed and referred to as a priority set. 
         [0029]      FIG. 2  illustrates a CCBS service procedure according to an exemplary embodiment of the present invention. 
         [0030]    Referring to  FIG. 2 , in step  230 , a Mobile Originator (MO)  200  transmits a setup request message (SETUP) and attempts to connect a call to a Mobile Terminal (MT)  220 . After receiving the setup request message (SETUP), a network apparatus  210  determines whether to apply the CCBS service to the MT  220  when the MT  220  is presently in a Network Determined User Busy (NDUB) state. In step  232 , the network apparatus  210  transmits to the MT  220  a priority request message (FACILITY) requesting a priority value of the MO  200  when applying the CCBS service. The priority request message (FACILITY) can include “NotifySS” for requesting a priority of the MO  200  on the CCBS service. The “NotifySS” can include “SS-Code” that represents the CCBS service and an address (a telephone number, etc.) of the MO  200 . In other words, the network apparatus  210  transmits the priority request message (FACILITY) of step  232 , for example, in the form of “Invoke=NotifySS(SS-Code=CCBS, Address of A)”. 
         [0031]    The MT  220  receiving the priority request message (FACILITY) searches the priority set. In step  243 , the MT  220  includes a priority value of the MO  200 , which is included in the priority request message (FACILITY), in a priority response message (FACILITY) and transmits the priority response message (FACILITY) to the network apparatus  210 . 
         [0032]    The priority response message (FACILITY) can include “PrioritySS” that represents a priority of the MO  200  on the CCBS service. The “PrioritySS” can include “SS-Code” that represents the CCBS service and a priority value of the MO  200 . In other words, the MT  220  transmits the priority response message (FACILITY) of step  234 , for example, in a form of “ReturnResult=Priority(SS-Code=CCBS, PriorityValue, etc)”. 
         [0033]    After receiving the priority response message (FACILITY) and detecting the priority of the MO  200 , the network apparatus  210  stores in a queue according to the detected priority information on a call initiated by the MO  200 . For example, a call initiated by the MO  200  is stored in a first position of the queue when a priority of the call initiated by the MO  200  is detected as “0” in a situation where a priority is all detected as “1”. 
         [0034]    In step  240 , the network apparatus  210  transmits a circuit disconnect message (DISCONNECT) to the MO  200  and notifies that the MT  220  is in the NDUB state. 
         [0035]    In step  250 , the network apparatus  210  transmits to the MO  200  a setup possibility notification message (RECALL) in case where the MO  200  is out of the NDUB state and there is call information on the MO  200  in the queue for the CCBS service. In step  260 , the MO  200  receiving the setup possibility notification message (RECALL) can resume a call procedure when the MT  220  is in the telephony possibility state. 
         [0036]      FIG. 3  is a block diagram of the network apparatus for the CCBS service according to an exemplary embodiment of the present invention. 
         [0037]    Referring to  FIG. 3 , the network apparatus includes a controller  310 , an interface module  320 , a storage unit  330 , a priority comparator  340 , and a priority control unit  350 . 
         [0038]    The controller  310  controls a general operation for the CCBS service. For example, the controller  310  controls a priority comparator  340  to determine if a MT is using the CCBS service and receive the determination result. The controller  310  transmits a priority request message requesting a priority of an MO to the MT, receives a priority response message from the MT, provides the priority response message to the priority control unit  350 , and stores call information on the MO in a queue for the CCBS service according to the priority. The controller  310  transmits a setup possibility notification message (RECALL) to the MO according to the priority when the MT is out of the NDUB state. 
         [0039]    The priority comparator  340  determines if the MT is using the CCBS service by control and provision information of the controller  310 , and provides the determination result to the controller  310 . 
         [0040]    The priority control unit  350  stores call information on the MO in a queue for the CCBS service according to the priority by the control and provision information of the controller  310 . 
         [0041]    The storage unit  330  stores a program for controlling a general operation of the apparatus and temporary data generated during the execution of various programs. Particularly, the storage unit  330  includes a queue for the CCBS service according to the present invention. 
         [0042]    The interface module  320 , a module for communicating with other nodes, can include a wired processor and a baseband processor. The wired processor receives an optical communication signal or other wired signals through an optical cable, converts the optical communication signal or other wired signals into a baseband signal, and provides the baseband signal to the baseband processor. The wired processor receives a baseband signal from the baseband processor, converts the baseband signal into an optical signal or other wired signals, and transmits the optical signal or other wired signals by a wired path. 
         [0043]    In the above construction, the controller  310  can perform both functions of the priority comparator  340  and the priority control unit  350 . Such separate construction and illustration of the present invention is to distinguish and describe the respective functions. Thus, when a product is actually realized, it can be either constructed for the controller  310  to process all of the functions of the priority comparator  340  and the priority control unit  350  or can be constructed for the controller  310  to process only a part of the functions. 
         [0044]      FIG. 4  is a block diagram of the MT for the CCBS service according to an exemplary embodiment of the present invention. 
         [0045]    Referring to  FIG. 4 , the MT includes a controller  410 , an interface module  420 , a storage unit  430 , a priority comparator  440 , and a priority analyzer  450 . 
         [0046]    The controller  410  controls the overall operation for providing the CCBS service. For example, the controller  410  receives a priority request message from the network apparatus and provides the priority request message to the priority analyzer  450 . The controller  410  controls the priority analyzer  450  to analyze and provide information (e.g., a telephone number) on a MO that is included in the priority request message. The controller  410  provides the information on the MO to the priority comparator  440  and controls the priority comparator  440  to compare the information on the MO with a priority set and provide a priority value of the MO. The controller  410  transmits to the network apparatus through the interface module  420  a priority response message including the priority value. 
         [0047]    The priority analyzer  450  analyzes the information on the MO by control and provision information of the controller  420  and provides the analysis result to the controller  420 . 
         [0048]    The priority comparator  440  performs a comparison with a priority set by the control and provision information of the controller  410 , decides the priority value of the MO, and provides the decision result to the controller  410 . 
         [0049]    The storage unit  430  stores a program for controlling the overall operation of the apparatus and temporary data generated during the execution of programs. Particularly, the storage unit  430  stores a priority set for a MO according to the present invention. 
         [0050]    The interface module  420 , a module for communicating with other nodes, includes a Radio Frequency (RF) processor and a baseband processor. The RF processor receives a signal through an antenna, converts the signal into a baseband signal, and provides the baseband signal to the baseband processor. The RF processor receives a baseband signal from the baseband processor, converts the baseband signal into an RF signal for actual transmission through the air, and transmits the RF signal through the antenna. 
         [0051]    In the above construction, the controller  410  can perform both functions of the priority comparator  440  and the priority analyzer  450 . Such separate construction and illustration of the present invention is to distinguish and describe the respective functions. Thus, when a product is actually realized, it could be either constructed for the controller  410  to process all of the functions of the priority comparator  440  and the priority analyzer  450  or could be constructed for the controller  410  to process only part of the functions. 
         [0052]      FIG. 5  is a flowchart of a procedure of operating the network apparatus for the CCBS service according to an exemplary embodiment of the present invention. 
         [0053]    Referring to  FIG. 5 , in step  510 , the controller of the network apparatus receives a setup request message from an MO. In step  512 , the controller controls the priority comparator of the network apparatus to determine if an MT is using the CCBS service, and receives the determination result. 
         [0054]    In step  515 , the controller transmits to the MT a priority request message including information (e.g., a telephone number) on the MO and requests a priority value of the MO, when the MT is using the CCBS service. 
         [0055]    In step  545 , the controller transmits a circuit disconnect message (DISCONNECT) to the MO and signals that the MT is in the NDUB state, when the MT is not using the CCBS service. 
         [0056]    In step  520 , the controller receives from the MT a priority response message including the priority value, provides the priority response message to the priority control unit of the network apparatus, and stores call information on the MO in a queue according to the priority. In the case where the MO has the highest priority, the call information on the MO is stored in a first position of the queue. 
         [0057]    In step  525 , the controller transmits a circuit disconnect message to the MO and signals that the MT is in the NDUB state. 
         [0058]    In step  530 , the controller determines if the MT is out of the NDUB state. In step  540 , the controller transmits a setup possibility notification message to the MO in a sequence of the call information stored in the queue, when it is determined that the MT is out of the NDUB state. 
         [0059]    In step  535 , the controller performs a general function (e.g., CCBS processing for another MO), when it is determined that the MT is in the NDUB state. 
         [0060]    The process according to the present invention is terminated. 
         [0061]      FIG. 6  is a flowchart of a procedure of operating the MT for the CCBS service according to an exemplary embodiment of the present invention. 
         [0062]    Referring to  FIG. 6 , in step  605 , the controller of the MT is assumed to be in a call connection state with a MO. 
         [0063]    In step  610 , the controller determines if it receives from the network apparatus a priority request message requesting a priority value of the MO. In step  615 , the controller provides the priority request message to the priority analyzer and controls the priority analyzer to provide information (e.g., a telephone number) on the MO, when receiving the priority request message. 
         [0064]    In step  620 , the controller receives the information on the MO, provides the received information to the priority comparator, and controls the priority comparator to decide and provide a priority value of the MO according to a priority set. 
         [0065]    In step  625 , the controller transmits to the network apparatus a priority response message including the priority value of the MO. 
         [0066]    The process according to the present invention is then terminated. 
         [0067]    As described above, the present invention can apply a priority to a given CCBS service and thus, upon setting of a high priority to a call of a MT, can receive a notification about the call even when a capacity of a queue for storing information on a call not received in the NDUB state is exceeded. Also, information, which is the representation of a priority according to the present invention, is applicable to not only the CCBS service but also other supplementary services. 
         [0068]    Alternate embodiments of the present invention can also comprise computer readable codes on a computer readable medium. The computer readable medium includes any data storage device that can store data that can be read by a computer system. Examples of a computer readable medium include magnetic storage media (such as ROM, floppy disks, and hard disks, among others), optical recording media (such as CD-ROMs or DVDs), and storage mechanisms such as carrier waves (such as transmission through the Internet). The computer readable 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 construed by programmers of ordinary skill in the art to which the present invention pertains. 
         [0069]    While the invention has been shown and described with reference to certain preferred 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.