THE RING SERVICE SYSTEM AND METHOD Technical Field [1] This invention relates to ring service system and method, and more particularly, relates to the ring service system and method whereby provide recipient's mobile terminal with the ring tone which is assigned by an originator, the subscriber to the present ring service, as that of the recipient's mobile terminal. Background Art [2] Recently, the technology regarding the mobile communication in Korea has been growing rapidly enough to be the best in the world. People of all ages and both sexes carry the latest cellular phone, and also, subscribe to various supplementary services comprising enjoying a lot of contents such as game, video, etc. through the wireless Internet using the cellular phone. [3] As examples of those supplementary services, Calling Identification Display service, Lettering service, Coloring service, etc. are used to effectively show who is calling or unique individuality. [4] However, in the above Calling identification Display service or Lettering service, recipients cannot recognize who is calling without seeing the LCD screen of their own cellular phone through their eyes, and also, the recipients are not provided with an acoustic pleasure. In the meantime, the recipient may have in his own cellular phone the plurality of ring tones, each of which is associated with each of the plurality of phone numbers, whereby, at the time of calling from an originator with one of the phone numbers, the corresponding ring tone associated with the phone number are played from the recipient's cellular phone, and therefore, the recipient may enjoy an acoustic pleasure and also discriminate the originator. However, the setting which makes it possible can be performed only by the recipients, and therefore, it is somewhat restrictive. [5] The Coloring service enables the sound which is assigned by the recipient instead of usual ring back tone to be heard to originators who are calling to the recipient, so that the originators waiting for call connection are not tedious, and also, the sound rep¬ resenting the recipient's unique individuality is heard to the originators. However, this setting can also be performed only by the recipient, and therefore, it is somewhat re¬ strictive. Disclosure of Invention Technical Problem [6] The present invention is proposed to provide ring tone service system and method without any limits in the prior arts and provide unique amusement. The object of the present invention is to have an originator's unique individuality together with an acoustic pleasure to a recipient showed by ringing as ring tone of the recipient's mobile terminal the sound that is assigned by the originator, which is the reverse concept to the Coloring service. Technical Solution [7] The present invention discloses a ring service system for ringing, through the mobile communication networks, as a ring tone of the recipient's mobile terminal the sound which is assigned by an originator, the subscriber to the ring service, comprising: [8] a sound storage means for storing various sounds; [9] a sound assignment/setting means for the subscriber's assigning/setting the sound to be rung as the ring tone of the recipient's mobile terminal by selecting the sound from the sound storage means; [10] a subscriber-related information storage means for storing the subscriber's in¬ formation associated with the sound which is assigned by the subscriber; and [11] a control means for, in response to the established signal from the mobile com¬ munication networks according to call connection request from the mobile terminal of the originator of subscriber to the mobile terminal of the recipient, referring to the subscriber-related information storage means and sending the signal corresponding to the sound which is assigned by the subscriber to the ring service, through the mobile communication networks, [12] whereby, the signal corresponding to the sound which is assigned by the subscriber to the ring service is transmitted as call signal to the recipient's mobile terminal through the mobile communication networks and the sound which is assigned by the subscriber is reproduced from the call signal as the ring tone of the recipient's mobile terminal. [13] According to the above constitution of the present invention, the subscriber to the present ring service retrieves and selects the desired sound from the sound storage means for storing various sounds, through ARS, wired or wireless Internet, etc. using the sound assignment/setting means such as wired or wireless telephones, mobile terminals, PDAs, computers, etc. Thus assigned sound are reproduced as a ring tone of the recipient's mobile terminal when there is a call connection request from the mobile terminal which is carried by the subscriber to the ring service to the mobile terminal of the recipient. [14] The present invention also discloses a ring service system, in addition to the above constitution, wherein the subscriber to the ring service may assign the plurality of sounds depending upon the desired condition as the ring tone of the recipient's mobile terminal to be rung. [15] According to this, the subscriber to the present ring service may assign only one single sound so that the identical sound can be provided to all of the recipient's mobile terminals; may assign the plurality of sounds to have the ring tone of recipient's mobile terminal differentiated by time zone, namely, a designated classical sound in the morning, a designated popular song sound in the afternoon, etc.; and may have the sound designated differently by the number of recipient's mobile terminal. [16] The present invention also discloses a ring service system, in addition to the above constitutions, wherein the recipient may decide whether the sound which is assigned by the originator, the subscriber to the ring service, is allowed to be rung as the ring tone of the recipient's mobile terminal or not. [17] This determination by the recipient may be performed prior to providing the recipient, according to the present ring service, with the sound which is assigned by the originator, and also, may be performed at any time, for example, by the recipient's later disapproval of enjoying the ring service or the recipient's change to decision whether to approve or not. [18] The present invention discloses a ring service method for ringing, through the mobile communication networks, as a ring tone of the recipient's mobile terminal the sound which is assigned by an originator, the subscriber to the ring service, by selection from a sound storage means for storing various sounds, comprising steps of: [19] the established signal from the mobile communication networks according to call connection request from the mobile terminal of the originator of subscriber to the mobile terminal of the recipient being received by a control means; [20] a subscriber-related information storage means for storing the subscriber's in¬ formation associated with the sound which is assigned by the subscriber being referred to by the control means; [21] the signal corresponding to the sound which is assigned by the subscriber to the ring service being sent through the mobile communication networks by the control means; [22] the signal corresponding to the sound which is assigned by the subscriber to the ring service being transmitted as call signal to the recipient's mobile terminal through the mobile communication networks; and [23] the sound which is assigned by the subscriber to the ring service being reproduced from the call signal as the ring tone of the recipient's mobile terminal. [24] According to the above constitution of the present invention, the subscriber to the present ring service retrieves and selects the desired sound from the sound storage means for storing various sounds, through ARS, wired or wireless Internet, etc. using the sound assignment/setting means such as wired or wireless telephones, mobile terminals, PDAs, computers, etc. Thus assigned sound are reproduced as a ring tone of the recipient's mobile terminal when there is a call connection request from the mobile terminal which is carried by the subscriber to the ring service to the mobile terminal of the recipient. [25] The present invention also discloses a ring service method, in addition to the above constitution, wherein the subscriber to the ring service may assign the plurality of sounds depending upon the desired condition as the ring tone of the recipient's mobile terminal to be rung. [26] According to this, the subscriber to the present ring service may assign only one single sound so that the identical sound can be provided to all of the recipient's mobile terminals; may assign the plurality of sounds to have the ring tone of recipient's mobile terminal differentiated by time zone, namely, a designated classical sound in the morning, a designated popular song sound in the afternoon, etc.; and may have the sound designated differently by the number of recipient's mobile terminal. [27] The present invention also discloses a ring service method, in addition to the above constitutions, wherein the recipient may decide whether the sound which is assigned by an originator, the subscriber to the ring service, is allowed to be rung as the ring tone of the recipient's mobile terminal or not. [28] This determination by the recipient may be performed prior to providing the recipient, according to the present ring service, with the sound which is assigned by the originator, and also, may be performed at any time, for example, by the recipient's later disapproval of enjoying the ring service or the recipient's change to decision whether to approve or not. Advantageous Effects [29] According to the present ring service system and method, the sound which is assigned by an originator, the subscriber to the ring service, is reproduced in real time, without being stored in recipient's mobile terminal, as the ring tone of the recipient's mobile terminal. Brief Description of the Drawings [30] Fig. 1 is a block diagram showing a schematic constitution of the present invention; and [31] Fig. 2 is a flow chart showing processes of the present invention. Mode for the Invention [32] An embodiment of the present invention is now described referring to the ac¬ companying drawings. [33] Fig. 1 is a block diagram showing a schematic constitution of the present invention. [34] The mobile communication networks(21) comprise Base Transceiver Station(BTS), Base Station Controller(BSC), Mobile Switching Center(MSC), Home Location Register(HLR), etc., which are not shown. [35] The Base Transceiver Station locates the originator's mobile terminal(22) and the recipient's mobile terminal(23), and transmits/receives voice signals and data signals between the mobile terminals(22, 23), wherein the BTS accepts call attempt from the originator's mobile terminal(22) to the recipient's mobile terminal(23) through the traffic channel of signaling channels, and then, forwards the accepted call attempt to Originating Base Station Controller. [36] The Base Station Controller performs the control of the Base Transceiver Station and various call process functions such as the support of inbound/outbound call at the Base Transceiver Station, message processing, etc., and forwards the call request received through the Base Transceiver Station to the Mobile Switching Center. [37] The Mobile Switching Center establishes the channel between different com¬ munication terminals such as mobile terminals(22, 23), controls overall traffic and call processes, and sends the signal which has a ring tone of the recipient's mobile terminal(23) rung at call request from the originator's mobile terminal(22). [38] The Home Location Register stores the subscriber's information such as the in¬ formation on the subscription to supplementary service. [39] In addition to the above constitution, the ring service system according to the present invention comprises a sound storage means(ll), a sound assignment/setting means(12), a subscriber-related information storage means(13) and a control means(14). [40] The sound storage means(l 1) stores various sounds such as music, curative sounds, functional sounds, natural sounds, voice, etc., and the subscriber to the present ring service searches the sound storage means(ll) for the desired sound using the sound assignment/setting means(12). [41] As the sound assignment/setting means(12), cellular phone, PDA, personal computer, wired telephone, etc. may be used, and anything that makes it possible to retrieve and assign/set the desired sound from the sound storage means(l 1) will do. [42] Not shown in detail, if the cellular phone or the wired telephone are used as the sound assignment/setting means(12) and the desired sound is assigned/set through the phone call, the sound assignment/setting means(12), the control means(14), etc. may communicate with each other, for example, through Public Switched Telephone Network(PSTN). Also not shown in detail, if the computer, the cellular phone or the PDA are used as the sound assignment/setting means(12) and the desired sound is assigned/set through the wireless or wired Internet, the sound assignment/setting means(12), the control means(14), etc. may communicate with each other, for example, through Internet Protocol(TP) networks. [43] The subscriber-related information storage means(13) stores, for example, the in¬ formation on phone number of mobile terminal of the subscriber to the present ring service, associated with the sound which is assigned by the subscriber. [44] The subscriber to the present ring service may assign only one single sound so that the identical sound is rung as the ring tone of all the recipient's mobile terminals; may assign the plurality of sounds depending upon the desired condition to have the ring tone of the recipient's mobile terminal rung differently by time zone, for example, a classical music in the morning, a pop in the afternoon, etc.; and may have the sound designated differently by the number of recipient's mobile terminal. [45] The control means(14) interconnects and controls the sound storage means(l 1), the sound assignment/setting means(12) and the subscriber-related information storage means(13), transmits/receives various signals to/from the mobile communication networks(21) and performs overall signal processing functions such as signal encoding/decoding. [46] Now, referring to Fig.2, the operation of the present ring service system is described as an example. [47] When, from the originator's mobile terminal(22) subscribing to the present ring service system, the call connection request to recipient's mobile terminal(23) managed by Receiving Mobile Switching Center is made, the Originating Mobile Switching Center requests the recipient location information to the Home Location Register while it reads out the stored information on originator's setting of the ring service, and then, if it is determined that the originator's mobile terminal(22) subscribes to the present ring service, the resultant signals containing the number of originator's mobile terminal(22) is transmitted to the control means(14), at step(Sl). [48] Then, at step(S2), the control means(14), in response to the received signals, refers to the subscriber-related information storage means(13), and then, at step(S3), transmits the signal corresponding to the sound that is assigned/set by the originator. [49] In the meantime, the Home Location Register requests routing information to the Receiving Mobile Switching Center in response to the request for recipient location in¬ formation from the Originating Mobile Switching Center. The Receiving Mobile Switching Center transmits the routing information(Temporary Local Directory Number; TLDN) to the Home Location Register, in response to the request signal for routing information received from the Home Location Register. Then, the Home Location Register transmits the recipient location information to the Originating Mobile Switching Center using the received routing information. [50] Then, at step(S4), the Mobile Switching Center transmits a call signal to the recipient's mobile terminal(23), where the Mobile Switching Center transmits the signal received from the control means(14), namely, the signal corresponding to the sound that is assigned/set by the originator, which is different from the general call signal. [51] The signal corresponding to the sound which is assigned/set by the originator is received at the recipient's mobile terminal(23) and the sound is reproduced as a ring tone through sequential processes by the relevant software and hardware built in the recipient's mobile terminal(23), at step(S5). [52] When the Mobile Switching Center recognizes the response from the recipient's mobile terminal(23), it transmits the established signal to the control means(14), and then, the control means(14), in response to the established signal, releases the transmission of the signal corresponding to the sound which is assigned by the originator. At the time of responding from recipient's mobile terminal(23), re¬ production of the sound is also released. [53] According to this constitution, the sound which is assigned/set by the originator, the subscriber to the present ring service, is reproduced in real time as the ring tone of recipient's mobile terminal. [54] Not shown, the present ring service system may be additionally constituted so that the recipient may decide whether the sound which is assigned by the originator, the subscriber to the ring service, is allowed to be rung as the ring tone of recipient's mobile terminal(23) or not. [55] This determination by the recipient may be performed prior to providing the recipient, according to the present ring service, with the sound which is assigned by the originator, and also, may be performed at any time, for example, by the recipient's later disapproval of enjoying the ring service or the recipient's change to decision whether to approve or not. [56] Although a preferred embodiment of the present invention has been described for il¬ lustrative purposes, various modifications are possible without departing from the scope and spirit of the invention. For example, although the present invention has been described with respect to mobile terminals, it is applicable to wired phones.