Abstract:
A method for managing codec information of Media Gateways (MGWS) in a Mobile Switching Center (MSC) server, comprising receiving a registration request from at least one or more MGWs, registering the request MGW, and transmitting a codec information request message to the registered MGW to thus update MGW codec information that the MSC server itself manages using the codec information received from the MGW.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2004-0097935, filed Nov. 26, 2004, the contents of which are hereby incorporated by reference herein in their entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an information managing method of a Mobile Switching Center (MSC) server, and particularly, to a codec information managing method Media GateWays (MGWs) in a MSC server.  
         [0004]     2. Background of the Related Art  
         [0005]     In general, a Universal Mobile Telecommunication System (UMTS) is a European-type third generation mobile communications system that has evolved from a Global System for Mobile communication (GSM). The UMTS is intended to provide various mobile communication services by combining Radio Access Network (RAN) with Wideband Code Division Multiple Access (W-CDMA) based on the GSM.  
         [0006]     The specification of the UMTS is currently being developed by a standardization group called as a Third Generation Partnership Project (3GPP). The 3GPP proposes standardization that has been stepwise developed to include more improved functions, and each development step for the standardization is divided as Release (R). Among them, in a 3GPP R4, a Mobile Switching Center/Visitor Location Resister (MSC/VLR) which is a core network node belonging to a circuit switched region is divided into Mobile Switching Center (MSC) servers and Media Gateways (MGWs).  
         [0007]      FIG. 1  is a view illustrating an exemplary structure of UMTS system described in a typical 3GPP R4.  
         [0008]     As illustrated in  FIG. 1 , the MSC server  10  is connected to the MGW  20  via an Mc interface. The MSC servers  10  are connected therebetween via an Nc interface, while the MGWs  20  are connected therebetween via an Nb interface. The MSC server  10  or the MGW  20  is connected to a Universal Mobile Telecommunications System Radio Access Network (UTRAN) via an lu interface. The MSC  10  and the MGW  20  may be connected to a Public Switching Telephone Network (PSTN) as well. Here, the UTRAN may include a Radio Network Controller (RNC)  30  and a user terminal (User Equipment: UE)  40 . The MSC server  10  uses a Media Gateway Control (MEGACO, ITU name is H.248) as a protocol for controlling the MGW  20 .  
         [0009]     The MSC server  10  includes a VLR function to perform a management of mobility of a terminal and a control for the MGW  20 . Also, the MSC servers  10  are connected to each other using a Bearer Independent Call Control (BICC), which is a signal protocol spec between soft switches to perform a transferring of a call signal and a voice data in a public telephone network or an intelligent network to a packet-based communications network. The BICC is used for an interworking between soft switches which are used to create a next generation network. Further, the MSC server  10  is connected to the RNC  30  via a Radio Access Network Application Part (RANAP).  
         [0010]     The MGW  20  performs a substantial switching function and an InterWorking (I/W) function of a network, and so on. The MGW  20  may additionally perform a function such as performing a conversion of a Voice over Internet Protocol (VoIP) call into a circuit switched packet as well as functions as a transcoder, an echo cancellation, a modem, and the like. A CN bearer between MGWs  20  and an lu bearer between the MGW  20  and the RNC  30  perform a signal processing using AAL2 and ALCAP. The RNC  30  is connected to the UE 40 via a radio bearer.  
         [0011]     A MGW codec information managing method in the UMTS system of 3GPP R4 having such construction will now be explained.  
         [0012]     Referring to  FIG. 1 , when a call is established between two terminals  40 , each MGW  20  generates a logical entity referred to as a termination for processing the corresponding call, and switches corresponding terminations to thus communicate between the two terminals  40 . At this time, the MSC server  10  must manage information of Coder and Decoder (Codec) of the MGW  20  in order to perform a Transcoder Free Operation (TrFO) function. Here, the termination refers to a logical entity for indicating a media stream used in each MGW  20 .  
         [0013]     The TrFO function refers to a function of matching codec information of a plurality of MGWs  20 , namely, a function of preventing a transcoder from being used as much as possible. That is, if each MGW  20  supports several codec, codec information of each MGW  20  is previously determined in order to fully select the same codec, and accordingly negotiation is progressed to select the best operating codec, such function being referred to as the TrFO. Therefore, the MSC server  10  performs the codec function together with the control function, and the MGW  20  performs the switching function of an actual termination.  
         [0014]     Accordingly, in the related art, the codec negotiation has been performed upon performing the TrFO function after creating codec information to be used between the MSC server and the MGW by a data process in a system. That is, the MSC server  10  performs the codec negotiation from a sending end to a receiving end using the codec information to match codec information between terminations used in each MGW  20 , thereby preventing the transcoder from being used.  
         [0015]     However, because the 3GPP standardization has not defined how to manage the codec information of MGW, the codec information has been managed by an individual operator. As a result, when the codec information of the MGW is varied, the operator had to manually match codec information of each MGW to match information between systems. Thus, in the related art, when the operator did not update the codec information of each MGW by mistake, the codec selected by the codec negotiation could not be used in the MGW.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0016]     Therefore, an object of the present invention is to provide a method for efficiently managing codec information of a MGW.  
         [0017]     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a MGW codec information managing method in a Mobile Switching Center (MSC) server which interworks with at least one or more Media GateWays (MGWs), the method comprising receiving a registration request from a MGW, registering the requested MGW, transmitting a codec information request message to the registered MGW to update MGW codec information using the codec information received from the corresponding MGW.  
         [0018]     Preferably, the MGW codec information is codec information used in each MGW.  
         [0019]     Preferably, the codec information request message is an AuditValue message used when the MSC server desires to know information with respect to a termination.  
         [0020]     Preferably, the codec information request message is constructed when a MGW is registered, the MSC server creates a new codec type using a Man Machine Command (MMC) command, or an operator manually requests an updating of the MGW codec information.  
         [0021]     The updating of the MGW codec information in the MGW codec information managing method may comprise a MMC command processing unit requesting the updating of the codec information from a MEGACO processing unit, the MEGACO processing unit transmitting the codec information request message to the MGW, the MGW transmitting a codec information reply message to the MEGACO processing unit, the MEGACO processing unit updating the codec information used in each MGW using several codec information contained in the codec information reply message, and notifying a completion of the codec information updating to the MMC command processing unit when the codec information is completely updated.  
         [0022]     Preferably, the codec information updating request is transmitted when the MGW is registered, the MMC command processing unit generates a new codec type, or an operator requests the updating of the codec information.  
         [0023]     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.  
         [0025]     In the drawings:  
         [0026]      FIG. 1  is a schematic view illustrating an exemplary construction of a typical UMTS system described in a 3GPP R4;  
         [0027]      FIG. 2  is a block diagram illustrating an interworking between a MSC server and a plurality of MGWs;  
         [0028]      FIG. 3  is a flow chart illustrating sequential steps of an exemplary MGW codec information managing method in a MSC server according to the present invention;  
         [0029]      FIG. 4  is a signal flow chart illustrating a MGW codec information managing method when a MSC server interworks with a plurality of MGWs;  
         [0030]      FIG. 5  is a view illustrating an exemplary construction of an AuditValue request message and an AuditValue reply message used in the present invention; and  
         [0031]      FIG. 6  is a signal flow chart illustrating an exemplary operation of each block within a MSC server when a MSC server manages MGW codec information 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0033]     The present invention is directed to a method for managing codec information of a plurality of MGWs in a MSC server, the MSC server interworking with the plurality of MGWs.  
         [0034]     Referring to  FIG. 2 , for example, a MGW  21  initially accesses the MSC server  10  interworking therewith, and performs a registration process. Upong completing the registration process, the MSC server  10  transmits an AuditValue message to the MGW  21  to receive codec information of the MGW  21  therefrom. Such operations are repeatedly performed, so as to match codec information according to MGWs  21 ,  22  and  23 . Here, the AuditValue denotes a message (or a command) used to recognize information with respect to a termination of the MGW.  
         [0035]      FIG. 3  is a flow chart illustrating an exemplary MGW codec information managing method in a MSC server according to the present invention.  
         [0036]     Referring to  FIG. 3 , first, the MGW  20  initially accesses the MSC server  10 , and requests its registration from the MSC server  10  (S 10 ). When the MGW  20  requests its registration, the MSC server  10  transmits a registration reply message to the MGW  20 (S 11 ), and then requests codec information from the MGW  20  using the AuditValue message transmitted between the MSC server  10  and the MGW  20 (S 12 ).  
         [0037]     The MGW  20  replies to the codec information request of the MSC server  10  to thus transmit its codec information to the MSC server  10 (S 13 ). The MSC server  10  then uses the received codec information of the MGW  20  to update the MGW codec information that the MSC server itself manages (S 14 ).  
         [0038]      FIG. 4  is a signal flow chart illustrating a MGW codec information managing method when the MSC server interworks with a plurality of MGWs in the present invention.  
         [0039]     When the MGW# 0   21  initially accesses the MSC server  10 , the MGW# 0   21  transmits a MGW registration request message to the MSC server  10  to request its registration therein (S 20 ). The MSC server  10  registers the MGW# 0   21  therein to thereafter transmit a MGW registration reply message to the MGW# 0   21  (S 21 ).  
         [0040]     Upon completing the registration process, the MSC server  10  transmits an AuditValue request message to the MGW# 0   21  to request its codec information (S 22 ). The MGW# 0   21  transmits its codec information to the MSC server  10  using an AuditValue reply message (S 23 ).  
         [0041]     Accordingly, the MSC server  10  uses the received codec information of the MGW# 0   21  to update the MGW codec information that the MSC server  10  itself manages (S 24 ).  FIG. 5  illustrates an exemplary construction of the AuditValue request message and the AuditValue reply message.  
         [0042]     When MGW# 1   22  and MGW# 2   23  initially access the MSC server  10 , the same operation as that of the MGW# 0   21  is performed. That is, when the MGW# 1   22  initially accesses the MSC server  10 , the MGW# 1  performs the registration process into the MSC server  10  (S 30  and S 31 ). When the registration process is completed, the MSC server  10  transmits the AuditValue request message to the MGW# 1   22  to request the codec information of the MGW# 1   22  (S 32 ). The MGW# 1   22  then transmits its codec information to the MSC server  10  using the AuditValue reply message (S 33 ). The MSC server  10  thus uses the received codec information of the MGW# 1   22  to update the MGW codec information that the MSC server  10  itself manages (S 34 ).  
         [0043]     When the MGW# 2   23  initially accesses the MSC server  10 , the MGW# 2   23  also performs the registration process into the MSC server  10  (S 40  and S 41 ). When the registration process is completed, the MSC server  10  transmits the AuditValue request message to the MGW# 2   23  to request the codec information of the MGW# 2   23  (S 42 ). The MGW# 2   23  transmits its codec information to the MSC server  10  using the AuditValue reply message (S 43 ). The MSC server  10  thus uses the received codec information of the MGW# 2   23  to update the MGW codec information that the MSC server  10  itself manages (S 44 ). That is, the MSC server  10  performs such processes to match codec information of the MGWs  21 ,  22  and  23  that it manages.  
         [0044]      FIG. 6  is a signal flow chart illustrating an exemplary operation of each block within the MSC server when the MSC server manages the MGW codec information. Here, the reference numeral  11  denotes a Man Machine Command (MMC) command processing unit, and the reference numeral  12  denotes a Media Gateway Control (MEGACO) processing unit.  
         [0045]     As illustrated in  FIG. 6 , after registering the MGW, when the MSC server  10  generates new codec information (a new codec type) using a MMC command or an operator manually requests an updating of the MGW codec information, the MMC command processing unit  11  requests the updating of the codec information from the MEGACO processing unit  12  (S 50  and S 51 ). The MEGACO processing unit  12  transmits the AuditValue request message to the MGW  20  in response to the updating request. At this time, a codec type which is actually used among the generated codec types is updated based on the codec information received from each MGW.  
         [0046]     The MGW  20  having received the AuditValue request message transmits the AuditValue reply message containing its codec information to the MEGACO processing unit  12  of the MSC server  10  (S 53 ). The MEGACO processing unit  12  updates the MGW codec information (S 54 ), and then notifies the MMC command processing unit  11  that the MGW codec information is completely updated (S 55 ).  
         [0047]     Accordingly, the MSC server  10  may generate codec types that it manages, and the corresponding (generated) codec types can be updated to be used by receiving the codec information from each MGW  20 . That is, when the MSC server performs the TrFO function, the MSC server  10  automatically manages codec information that the MGW interworking with the MSC server  10  can support.  
         [0048]     As described above, in the present invention, when the MSC server performs the TrFO function, the MSC server automatically manages the codec information that the MGW interworking with the MSC server  10  can support, whereby the codec information can be conveniently used and shortcomings caused in the related art when the operator did not update the codec information can be effectively prevented.  
         [0049]     As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.