Abstract:
The present invention relates to a method for adding background sound to mobile communication telephone talking and a communication system thereof. In the method of the present invention, a background sound system is added into corresponding talk at the time of establishing a talking link between the calling mobile communication terminal and the called mobile communication terminal based on contracting information of calling and/or called parties. In the communication system of the present invention, one or more than one background sound service system is introduced into conventional communication system, The background sound service system comprises at least a switching device, a background sound storage device, a background sound playing device and a control device that are connected to each other. According to the present invention, new telecommunications valued-added services may be added in existing mobile communication networks, making the talking between the calling and called parties more interesting and humanized. Meanwhile, a system capable of storing, managing and setting background sound data is provided to background sound providers, background sound subscribers and background sound service operators.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a method for adding background sound to mobile communication telephone talking and a communication system thereof. In particular, the present invention relates to a method for adding background sound to mobile communication telephone talking in which background sound of a non-talking party is played during mobile communication voice talking in order to make the talking more interesting, and corresponding communication system, thereof. The present invention pertains to the field of communication technology. 
       DESCRIPTION OF THE RELATED ART 
       [0002]    With the development of the system and market of communication technology, demands of people for communication have become more and more, diversified. Therefore, as for these diversified demands, various communication technologies have been developed and relevant, communication services have been produced and introduced to meet multilevel and multicolored requirements of people for communication. In the field of conventional voice talking, some communication enterprises have already provided sound-effect-based technologies and corresponding services. For example, one of such services is the coloring ring back tone service, which makes a calling party receiving the service hear the sound effect ordered by the called party after the calling is connected and before the talking, and changes the conventional monotonous ring back tone into colorful and individualized sound effect, adding new taste in the talking. 
         [0003]    Although more and more technologies for voice talking are introduced continuously, communication technologies which can change the sound effect in the actual talking have not been greatly improved. The existing voice talking technology is directed more to how to reduce the noise interference during the talking and how to improve the quality of talking voice signal. However, it never relates to changing sound effect during the talking. Actually, people have various demands and hope to play during the talking the sound generated by the non-talking parties, i.e. a background sound. 
         [0004]    Background sounds are those other sounds added to the sounds of respective parties of a talking. These sounds may be set depending on the people&#39;s demands, such as sounds of pets, funny popular words, feeling expressing voices, sounds of water of the nature and atmosphere effect sounds, etc. Playing these sounds generated by the non-talking parties may change the monotonous talking mode in which pure voice is listened, and add sounds enlivening the atmosphere. This will make routine telephone talking more interesting. 
       SUMMARY OF THE INVENTION 
       [0005]    This section is for the purpose of summarizing sonic aspects of the present invention and to briefly introduce some preferred embodiments. Simplifications or omissions in this section as well as the title and the abstract of this disclosure may be made to avoid obscuring the purpose of the section, the title and the abstract. Such simplifications or omissions are not intended to limit the scope of the present invention. 
         [0006]    One aspect of the present invention is to provide a method for adding background sound to mobile communication telephone talking. In the method according to the present invention, a talking link of a third party which is provided by a background Sound system is added and a three-party talking is established at the time of establishing a talking link between the calling mobile communication terminal and the called mobile communication terminal. Meanwhile, the sound effect of the background sound may be controlled by the contracted party through its mobile communication terminal, making the conventional mobile .telephone talking more interesting and humanized due to the background sound added. 
         [0007]    Another aspect of the present: invention is to provide a communication system for adding a background sound to the mobile communication telephone talking. By means of the communication system according to the present invention, subscribers may order, modify, adjust or cancel the background sound service, and operators can rapidly introduce the background sound service and manage the background sound data. 
         [0008]    Other aspects, features, and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings. 
         [0009]    The first aspect of the present invention is achieved as follows: 
         [0010]    When a talking call is made by a calling mobile communication terminal to a called mobile communication terminal through a mobile communication base station and a mobile switching center of a calling party, the mobile switching center of the calling party, based upon the number of the called mobile communication terminal, sends the calling signal to the mobile switching center of the called party through mobile communication network; 
         [0011]    Upon receiving the calling signal, the mobile switching center of the called party judges the talking state of the called mobile communication terminal, and if the called mobile communication terminal is in an idle state, the mobile switching center of the called party sends a ringing signal to the called mobile communication terminal through a mobile communication base station and sends a ring back signal to the mobile switching center of the calling party through a mobile communication network; Otherwise, the mobile switching center of the called party sends an information that the called mobile communication terminal is in a non-idle, state to the mobile switching center of the calling party; 
         [0012]    Upon receiving the ring back signal sent by the mobile switching center of the called party, the mobile switching center of the calling party transfers the ring back signal to the calling mobile communication terminal through a mobile communication base station, and if the calling mobile communication terminal is a contracted subscriber of the background sound service, the mobile switching center of the calling party, upon receiving the off-hook signal of the called mobile communication terminal, establishes a three-party talking between the calling mobile communication terminal, the called mobile communication .terminal and the background sound service system and sends the information on the number of the calling mobile communication terminal to the background sound service system; The background sound service system plays the background sound ordered by the calling mobile communication terminal to the calling mobile communication terminal and the called mobile communication terminal through the mobile switching center of the calling party; 
         [0013]    If the calling mobile communication terminal is not a contracted subscriber of the background sound service, the mobile switching center of the calling party, upon receiving an off-hook signal of the called mobile communication terminal, establishes a two-party talking between the calling mobile communication terminal and the called mobile communication terminal; 
         [0014]    If the information that the called mobile communication terminal is in a non-idle state which is sent by the mobile switching center of the called party is received, the mobile switching, center of the calling party sends corresponding feedback signal to the calling mobile communication terminal according to relevant information .through a mobile communication base station and terminates this call: 
         [0015]    Upon on-hook of either of the calling mobile communication terminal or the called mobile communication terminal, the mobile switching center of the calling party and the mobile switching center of the called party release a corresponding talking link; If a three-party talking is made between the calling mobile communication terminal, the called, mobile communication terminal and the background sound service system by the mobile exchange of the calling party, the mobile switching center of the calling party releases simultaneously a corresponding talking link with the background sound, service system; The background sound service system ceases playing the background sound ordered by the calling mobile communication terminal to the calling mobile communication terminal and the called mobile communication terminal. 
         [0016]    When the mobile switching center of the called party sends a ringing signal to the called mobile communication terminal through a mobile communication base station, if the called mobile communication terminal is a contracted subscriber of the background sound service, the mobile switching center of the called party, upon receiving the off-hook signal of the called mobile communication terminal, establishes a three-party talking between the calling mobile communication terminal, the called mobile communication terminal and the background sound service system and sends information on the number of the called mobile communication terminal to the background sound service system; The background sound service system plays the background sound ordered by the called mobile communication terminal to the calling mobile communication terminal and the called mobile communication terminal through the mobile switching center of the called party; 
         [0017]    Upon on-hook of cither of the calling mobile communication terminal or the called mobile communication terminal, if a three-party talking is made, between the calling mobile communication terminal, the called mobile communication terminal and the background sound service system by the mobile exchange of the called party, the mobile switching center of the called party releases simultaneously a corresponding talking link with the background sound service system; The background sound service system ceases playing the background sound ordered by the called mobile communication terminal to the calling mobile communication terminal and the called mobile communication terminal. 
         [0018]    It should be noted that in the technical solution above, the calling mobile communication terminal and the called mobile communication terminal, may be or may not be a contracted subscriber of the background sound service; one may be a contracted subscriber of the background sound service while the other not; and both of them may be contracted subscribers of the background sound service. Thus, in the technical solution of the present invention, the background sound service system offers background sound playing services according to the contracting information only. In other words, even though the background sound service system has played background sound to the calling mobile communication terminal and the called mobile communication terminal according to the contracting state of the calling mobile communication terminal, it shall simultaneously play background sound to the calling mobile communication terminal and the called mobile communication terminal according to the contracting state of the called mobile communication terminal, so long as the called mobile communication terminal is also a contracted subscriber. If both of the calling mobile communication terminal and the called mobile communication terminal are contracted, when the calling mobile communication terminal and the called mobile communication terminal are engaged, two background sounds of the background sound service system can be heard in both the calling mobile communication terminal and the called mobile communication terminal. 
         [0019]    The other aspect of the present invention is achieved through the communication system as follows: 
         [0020]    More than one mobile communication terminals are connected to a mobile switching center through a mobile communication base station, in which more than one mobile switching centers are connected to each other through a mobile communication network; one or more than one background sound service systems are connected to the mobile communication network; the background sound service system comprises at least a switching device, a background sound storage device, a background sound playing, device and a control device that arc connected to each other; wherein, 
         [0021]    the switching device is used to connect to the mobile-communication network, establish a corresponding talking link in response to the instruction of establishing a talking link sent by the mobile switching center; it sends data of background sound to be played, by the background sound playing, device after the talking link is established, receives the control demand sent to the background sound system by the mobile communication terminal and transfers the control demand to the control device; 
         [0022]    the background sound storage device is used to store the data of background sound and playing parameters of contracted subscribers of background sound; 
         [0023]    the background sound playing device is used to read out the data of background sound to be played from the background sound storage device, package and send through the switching device the data of background sound according to relevant playing parameters and transmission protocols of the mobile communication network; 
         [0024]    the control device is used to control the playing operations of the background sound playing device according to the control demand when the talking link is established, or control the background sound playing device to stop the playing of the background sound of when the talking link is released. 
         [0025]    For the subscribers of the background sound to order, modify, adjust or cancel the background sound service, the background sound service operators to rapidly introduce the background sound service and manage the background sound data, and the background sound providers to be able to transmit the data of background sound to and store them in the background sound service system, the background sound service system of the present invention is further provided with a background sound data management device and connected to the internet through the background sound data management device; the background sound providers store the background sound in the background sound storage device, under the control of the background sound data management device through the Internet; the subscribers of the background sound interact with the background sound data management device through the Internet to order, modify, adjust or cancel the background sound service: the operators of the background sound manage the background sound data through the background sound data management device. 
         [0026]    In summary, the present invention provides a technical solution for adding background sound during the talking based on a mobile communication network, wherein the background sound may be added to the talking between the calling and the called parties arid therefore, new telecommunications valued-added services may be added in existing mobile communication networks, making the talking between the calling and called parties more interesting and humanized. Meanwhile, a system capable of storing, managing and setting background sound data is provided to background sound providers, background sound subscribers and background sound service operators. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0027]    The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
           [0028]      FIG. 1  is the processing flowchart of the first embodiment of the present invention; 
           [0029]      FIG. 2  is the processing flowchart of the first embodiment of the present invention with the called party being a contracted subscriber; 
           [0030]      FIG. 3  is flowchart with the calling party being not a contracted subscriber and the called party being a contracted subscriber: 
           [0031]      FIG. 4  is processing flowchart of the calling party and/or the called party of the present invention at roaming state. 
           [0032]      FIG. 5  is a general block diagram of a mobile communication system with a background sound service system; 
           [0033]      FIG. 6  is a block diagram of another mobile communication system of the present invention with a background sound service system. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]    The present invention will be described in detail with reference to the figures and embodiments. The detailed description of the invention is presented largely in terms of procedures, steps, logic blocks, processing, and other symbolic representations that directly or indirectly resemble the. operations of data processing devices coupled to networks. These process descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Numerous specific details are set forth in Order to provide a thorough understanding of the present invention. However, it will become obvious to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the present invention. 
       Embodiment 1 
       [0035]    Referring to  FIG. 1 , in one embodiment of the present invention, a calling mobile communication terminal MT 1  is a contracted subscriber of a background sound service and a called mobile communication terminal MT 2  is not a contracted subscriber of a background sound service. The contracting information of the calling, mobile communication terminal MT 1  is stored in a home location register HLR 1  of the calling mobile communication terminal MT 1 , and a mobile switching center MSC 1  of the calling party may acquire relevant contracting information through making access to the home location register HLR 1  of the calling mobile communication terminal MT 1  and simultaneous provides background sound playing service through a background sound service system BST 1  connected to the mobile communication network at the time of establishing a talking link with-the called mobile communication terminal MT 2 . Following is the flowchart in detail: 
         [0036]    The calling mobile communication terminal MT 1  begins a call to the called mobile communication terminal MT 2  through a mobile communication base station BS 1  (not shown) and the mobile switching center MSC 1  of the calling party. The mobile switching center MSC 1  of the calling party, based the number of the called mobile communication terminal MT 2 , sends a calling signal to a mobile switching center MSC 2  of the called party through the mobile communication network. 
         [0037]    Upon receiving, the calling signal, the mobile switching center MSC 2  of the called party judges the talking state of the called mobile communication terminal MT 2 . If the called mobile communication terminal MT 2  is in an idle state, the mobile switching center MSC 2  of the called party sends a ringing signal to the called mobile communication terminal MT 2  through a mobile communication base station BS 2  (not shown) and sends a ring back signal to the mobile switching center MSC 1  of the calling party through the mobile communication network. Otherwise, the mobile switching center MSC 2  of the called party sends to the mobile switching center MSC 1  of the calling party the information that the called mobile communication terminal MT 2  is in a non-idle state. 
         [0038]    Upon receiving the ring back signal sent by the mobile switching center MSC 2  of the called party, the mobile switching center MSC 1  of the calling party transfers the ring back signal to the calling mobile communication terminal MT 1  through the mobile communication base station BSI (not shown). If the calling mobile communication terminal MT 1  is a contracted subscriber of a background sound service, the mobile switching center MSC 1  of the calling party, upon receiving the off-hook signal of the called mobile communication terminal MT 2 , establishes a three-party talking between the calling mobile communication terminal MT 1 . the called mobile communication terminal MT 2  and the background sound service system BST 1  and sends the information on the number of the calling mobile communication terminal MT 1  to the background sound, service system BST 1 . The background sound service system BST 1  plays corresponding, background sound ordered by the calling mobile communication terminal MT 1  to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  through the mobile switching center MSC 1  of the calling party; 
         [0039]    If the information that the called mobile communication terminal MT 2  is in a non-idle state which is sent by the mobile switching center MSC 2  of the called party is received, the mobile switching center MSC 1  of the calling party; based upon relevant information, sends corresponding feedback signal to the calling mobile communication terminal MSC 1  through the mobile communication base station BS 1  (not shown) and terminates the call; 
         [0040]    Upon on-hook of either of the calling mobile communication terminal MT 1  or the called mobile communication terminal MT 1 , the mobile switching center MSC 1  of the calling party and the mobile switching center MSC 2  of the called party release a corresponding talking link. If a three-party talking is made between the calling mobile communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 1  by the mobile exchange MSC 1  of the calling party, the mobile switching center MSC 1  of the calling party releases simultaneously a corresponding talking link with the background sound service system BST 1 . The background sound service system BST 1  ceases playing the background sound ordered by the calling mobile communication terminal MT 1  to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . 
         [0041]    In the embodiment above, when the mobile switching center MSC 1  of the calling party judges whether the calling mobile communication terminal MT 1  is a contracted subscriber, the mobile switching center MSC 1  of the calling party makes access to the home location register HLR 1  of the calling mobile communication terminal Mil to obtain the information on the contracting of background sound service of; the calling mobile communication terminal MT 1 . Actually, the information on the contracting of background sound service of the Calling mobile communication terminal MT 1  is stored in the home location register HLR 1  of the calling mobile communication terminal MT 1 . When the mobile switching center MSC 1  of the calling party makes access to the home location register HLR 1 , it reads out a series of service sign information including the sign information on the background sound service, from which the mobile switching center MSC 1  of the calling party seeks out the sign indicating the contracting state of the background sound service, and makes judgment to acquire whether the calling mobile communication terminal MT 1  is contracted. 
         [0042]    When the calling mobile communication, terminal MT 1  is a contracted subscriber of the background sound service, the mobile switching center MSC 1  of the calling party establishes the three-party talking through the procedures as follows: 
         [0043]    The mobile switching center MSC 1  of the calling party sends to the background sound service system BST 1  instructions to establish a talking link at the time of establishing a talking link between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . The instruction is actually a call signaling sent to the switching device in the background sound service system. When the background sound service system BST 1  receives the call signaling sent, by the mobile, switching center MSC 1  of the calling party, as long as there is an idle channel in the switching device, the switching device will make response to the call signaling, and send off-hook signal to the mobile switching center MSC 1  of the calling party after the response is made. Upon receiving the response signal and the off-hook signal, the mobile switching center MSC 1  of the calling party adds the background sound service channel provided by the background sound service system BST 1  to the talking link between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 , to establish a three-party talking. 
         [0044]    During the playing of background sound ordered by the calling mobile communication terminal MT 1  by the background sound service system BST 1 , the background sound service system BST 1 , based upon the number information of the calling mobile communication terminal MT 1 , for example, “13901234567”, seeks out the contracting information on the calling mobile communication terminal MT 1  in the background sound service system BST 1  and acquires the playing parameters and playing contents from such information. Then it packages the playing contents and corresponding playing parameters in a format of mobile communication data and sends them to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  through the mobile switching center MSC 1  of the calling party. The calling mobile communication terminal MT 1 . and the called mobile communication terminal MT 2 , according to relevant protocols of mobile communication, processes respectively the received playing data, restores the data to corresponding audio signals and plays the signals together with corresponding voices. 
         [0045]    In order to control the background sound played during the talking, the Calling subscriber may press corresponding control buttons on the calling mobile communication terminal MT 1 . The values of such buttons are transferred by the calling mobile communication terminal MT 1  to the background sound service system BS 1  through the mobile communication base station BS 1  (not shown) and the mobile switching center MSC 1  of the calling party. The control device in the background sound service system BST 1  calls the functions corresponding to these values upon receiving relevant values of the buttons, to achieve the control of the playing of the background sound. 
         [0046]    For example, if the value of the button “*” corresponds to the function of pausing the playing of the background sound, the control device in the background sound service system BST 1 , upon receiving, value of the button “*” from the calling mobile communication terminal MT 1 , gives instructions to pause the playing for a period of time, for example, 5 seconds, to the playing device in the background sound service system BST 1 . Then the playing device in the background sound service system BST 1  pauses the playing of the background sound for that period of time. 
         [0047]    For another example, if the value of the button corresponds to the function of faster playing of the background sound, the control device in the background sound service system BST 1 . upon receiving value of the button “#” from the calling mobile communication terminal MT 1 , gives instructions to faster play the background sound, to the playing device in the background sound service system BST 1 . Then the playing device in the background sound service system BST 1  increases the speed of playing the background to the set speed. 
         [0048]    For a further example, if the value of a button corresponds to a certain level of volume of the background sound, the control device in the background sound service system BST, upon receiving value of the button from the calling mobile communication terminal MT 1  gives instructions to adjust the volume corresponding to the button, to the playing device in the background sound service system BST 1 . Then the playing device in the background sound service system BST 1  plays the background sound at that level of volume, when the corresponding data package is received by the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . 
         [0049]    All the control and adjustment above are based upon the operations of the buttons and their corresponding functions, and may be but not be limited to the contents as described above. They may also be the background, sound to be selected to play, adjusting the effect of the playing of the background sound, or controlling the start or stop of the playing of the background sound, etc. 
       Embodiment 2 
       [0050]    Referring to  FIG. 2 , in the second embodiment of the present invention, the calling mobile communication terminal MT 1  is a contracted subscriber of background sound service and the called mobile communication terminal MT 2  is also a contracted subscriber of background sound service. The contracting information of the calling mobile communication terminal MT 1  is stored in the home location register HLR 1  of the calling mobile communication terminal MT 1  and the contracting information of the called mobile communication terminal MT 2  is stored in the home location register HLR 2  of the called mobile communication terminal MT 2 . The corresponding contracting information may be acquired by the mobile switching center MSC 1  of the calling party through making access to the home location register HLR 1  of the calling mobile Communication terminal MT 1  and by the mobile switching center MSC 2  of the called party through making access to the home location register HLR 2  of the called mobile communication terminal MT 2 . The background sound service may be offered through the background sound service system BST 2  connected to the mobile communication network at the time of establishing a talking link with the. called mobile communication terminal MT 2 . Following is the detailed flowchart: 
         [0051]    The calling mobile communication terminal MT 1  makes a call to the called mobile communication terminal MT 2  through the mobile switching center MSC 1  of the calling party, establishes a three-party talking with the background sound service system BST 1 , acquires the contracting information on the calling mobile communication terminal MT 1  through the home location register HLR 1  of the calling mobile communication terminal MT 1 , and controls the playing of the background sound through the buttons. All the above steps are similar to those described in embodiment 1. What is different in embodiment 2 from embodiment 1 is that if the called mobile communication terminal MT 2  is also a contracted subscriber of background sound service, following procedures shall be carried out besides those as mentioned above: 
         [0052]    When the mobile switching center MSC 2  of the called party sends a ringing signal to the called mobile communication terminal MT 2  through the mobile communication base station BS 2  (not shown), if the called mobile communication terminal MT 2  is a contracted subscriber of the background sound service, the mobile switching center MSC 2  of the called party, upon receiving the off-hook signal of the called mobile communication terminal MT 2 , establishes a three-party talking between the calling mobile communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 2  and sends the information on the number of the called mobile communication terminal MT 2  to the background sound service system BST 2 , for example, “ 13901234567 ”. The background sound service system BST 2  plays the background sound ordered by the called mobile communication terminal MT 2  to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  through the mobile switching center MSC 2  of the called party; 
         [0053]    Upon on-hook of either of the calling mobile communication terminal MT 1  or the called mobile communication terminal MT 2 , if a three-party talking is made between the calling mobile communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 2  by the mobile exchange MSC 2  of the called party, the mobile switching center MSC 2  of the called party releases simultaneously a corresponding talking link with the background sound service system BST 2 . The background sound service system BST 2  ceases playing the background sound ordered by the called mobile communication terminal MT 2  to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . 
         [0054]    In the embodiment above, when the mobile switching center MSC 2  of the called party judges whether the called mobile communication terminal MT 2  is a contracted subscriber, the mobile switching center MSC 2  of the called party makes access to the home location register HLR 2  of the called mobile communication terminal MT 2  to obtain the information on the contracting of background sound service of the called mobile communication terminal MT 2 . Actually, the information on the contracting of background sound service of the called mobile communication terminal MT 2  is stored in the home location register HLR 2  of the called mobile communication terminal MT 2 . When the mobile switching center MSC 2  of the called party makes access to the home location register HLR 2 , it reads out a series of service sign information including the sign information on the background sound service, from which the mobile switching center MSC 2  of the called party seeks out the sign indicating the contracting state of the background sound service and makes judgment, to acquire whether the called mobile communication terminal MT 2  is contracted. 
         [0055]    When the called mobile communication terminal MT 2  is a contracted subscriber of the background sound service, the mobile switching center MSC 2  of the called party establishes the three-party talking through the procedures as follows: 
         [0056]    The mobile switching center MSC 2  sends the background sound service system BST 2  instructions to establish a talking link at the tithe of establishing a talking link between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . The instruction is actually a call signaling sent to the switching device in the background sound service system BST 2 . When the background sound service system BST 2  receives the call signaling sent by the mobile switching center MSC 2  of the called party, as long as there are idle, channels in the switching device, the switching device will make response to the call signaling, and send off-hook signal to the mobile switching center MSC 2  of the called party, after the response is made. Upon receiving the response signal and the off-hook signal, the mobile switching center MSC 2  of the called party adds the background sound service channel provided by the background sound service system BST 2  to the talking link between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 , to establish a three-party talking. 
         [0057]    During the playing of background sound ordered by the called mobile communication terminal MT 2  by the background sound service system BST 2 , the background sound service system BST 2 , based upon the number information of the called mobile communication terminal MT 2 , for example, “ 13901234567 ”, seeks out the contracting information on the called mobile communication terminal MT 2  in the. background sound service system BST 2  and acquires the playing parameters and playing contents from such information. Then it packages the playing contents and corresponding playing parameters in a format of mobile communication data and sends them to; the calling mobile, communication terminal MT 1  and the called mobile communication terminal MT 2  through (lie mobile switching center MSC 2  of the called party. The calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  processes respectively the received playing data according to relevant protocols of mobile communication, restores the data to corresponding audio signals and plays the signals together with corresponding voices. 
         [0058]    In order to control the background sound played during the talking, the called subscriber may press corresponding control buttons on the called mobile communication terminal MT 2 , and the values of such buttons are transferred by the called mobile communication terminal MT 2  to the background sound service system BST 2  through the mobile communication base station BS 2  (not shown) and the mobile switching center MSC 2  of the called party. The control device in the background sound service system BST 2  calls the functions corresponding to these values upon receiving relevant values of the buttons, to achieve, the control of the playing of the background sound. 
         [0059]    The manner in which the called mobile communication terminal MT 2  plays the background sound through control of the background sound service system BST 2  by the buttons is substantially the same as that in embodiment 1 and is not described further. 
         [0060]    It can be seen from the embodiment 2 above that, when both the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  are contracted subscribers of background sound service, if a talking link is made between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 , both of the calling and called panics can hear the background sound ordered by both the parties, and the calling and called parties can control or adjust the playing effect of respective background sound. 
       Embodiment 3 
       [0061]    Referring to  FIG. 3 , if the calling mobile communication terminal MT 1  is not a contracted subscriber of background sound service, the mobile switching center MSC 1  of the calling party, upon receiving the on-hook signal of the called mobile, communication terminal MT 2 , only establishes a two-party talking link between the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2 . If the called mobile communication terminal MT 2  is also not a contracted subscriber of background sound service, the said talking link is an ordinary voice talking link. But, if the called mobile communication terminal MT 2  is a contracted subscriber of background sound service, according to the method described in embodiment 2 above the mobile switching center MSC 2  of the called party will establish a three-party talking between the calling mobile, communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 2 . The background sound service system BST 2  plays background sound to the calling mobile communication terminal MT 1  and the called mobile communication terminal MT 2  simultaneously and is controlled only by the called mobile communication terminal MT 2 . 
       Embodiment 4 
       [0062]    Referring to  FIG. 4 , when the calling mobile communication terminal MT 1  is at roaming state, the mobile switching center MSC 1  of the calling party, making a call to the calling mobile communication terminal MT 1  according to the communication and switching standards of mobile communication networks, is actually the switching center MSCX 1  of the roamed location of the calling party. At this time, if the calling mobile communication terminal MT 1  makes a call to the called mobile communication terminal MT 2 , the switching center MSCX 1  of the roamed location of the calling party, instead of the mobile switching center MSC 1  of the calling party, establishes a talking link with, the called mobile communication terminal MT 2  and the background sound service system BST 1 . At this time, the information on the contracting sign of the calling mobile communication terminal MT 1  is stored in the visitor location register VLR 1  (not shown) of the roamed location of the calling mobile communication terminal MT 1 . In other words, when a three-party talking between the calling mobile communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 1  is establishing, the switching center MSCX 1  of the roamed location of the calling party needs to firstly make, access to the visitor location register VLR 1  (not shown) of the roamed location of the calling mobile communication terminal MT 1  to acquire the information on the contracting state of the calling mobile communication terminal MT 1 . 
         [0063]    Similar to the calling mobile communication terminal MT 1 , when the called mobile communication terminal MT 2  is at roaming state, the mobile switching center MSC 2  of the calling party, making a call lo the called mobile communication terminal MT 2  according to the communication and switching standards of mobile communication networks, is actually the switching center MSCX 2  of the roamed location of the called party. At this time, if the calling mobile communication terminal MT 1  makes a call to the called mobile communication terminal MT 2 , the Switching center MSCX 2  of the roamed location of the called party, instead of the mobile switching center MSC 2  of the called party, establishes a talking link with the calling mobile communication terminal MT 2 . At this time, the information on the contracting sign of the called mobile communication terminal MT 2  is stored in the visitor location register VLR 2  (not shown) of the roamed location of the called mobile communication terminal MT 2 . In other words, when the switching center MSCX 2  of the roamed location of the called party establishes a three-party talking between the calling mobile communication terminal MT 1 , the called mobile communication terminal MT 2  and the background sound service system BST 2 , the switching center MSCX 2  or the roamed location of the called party needs to first make access to the visitor location register VLR 2  (not shown) of the roamed location of the called mobile communication terminal MT 2  to acquire the information on the contracting state of the called mobile communication terminal MT 2 . 
       Embodiment 5 
       [0064]    Referring to  FIG. 5 , for the subscribers of the background sound to order, modify, adjust or cancel the back ground, sound service, the background sound service operators to rapidly introduce the background sound service and, manage the background sound data, and the background sound providers to be able to transmit the data of background sound to and store them in the background sound service system, it is required by the existing mobile communication system to incorporate a background sound service system to make the existing mobile communication system have a function of providing background sound playing. As an example of the present invention, the mobile communication system is characterized in that: more than one mobile communication terminals MT are connected to a mobile switching center MSG through a mobile communication base station BS (not shown), wherein more than one mobile switching centers MSC are connected to each other through a mobile communication network MW; one or more than one background sound service systems BST are connected to the mobile communication network MW; the background sound service system BST comprises at least a switching device BSTS, a background sound storage device BSTM, a background sound playing device BSTB and a control device BSTC that are connected to each other; wherein, 
         [0065]    The switching device BSTS is used to connect to the mobile communication network MW. establish a corresponding talking link in response to the instruction of establishing a talking link sent by the mobile switching center MSC. It sends data of background sound to be played by the background sound playing device BSTB after the talking link is established, receives the control demand sent to the background sound system by the mobile communication terminal MT and transfers the control demand to the control device BSTC. 
         [0066]    The background sound storage device BSTM is used to store the data of background sound and playing parameters of contracted subscribers of background sound. 
         [0067]    The background sound playing device BSTB is used to read out the data of background sound to be played from the background sound storage device BSTM; package and send through the switching device BSTS the data of background sound according to relevant playing parameters and transmission protocols of the mobile communication network MW. 
         [0068]    The control device BSTC is used to control the playing operations of the background sound playing device BSTB according to the control demand when the talking link is established, or control the stop of the playing of the background sound of the background sound playing device BSTB when the talking link is released. 
         [0069]    The switching device BSTS is provided in the mobile communication network MW and may be an existing switching device in the mobile communication network, or a switching module particularly provided in the background sound service system. Regardless of a switching device or a switching module, the switching, device BSTS is provided with a port for connecting to the mobile communication network MW according to mobile communication protocols, as well as ports interacting with the control device BSTC and the background sound playing device BSTB. 
         [0070]    The background sound playing device BSTB is connected to the control device BSTC for analyzing the control demand sent by the control device BSTC, and selecting the background sound to be played according to the analyzed demand, adjusting the speed, volume or effect of playing of the background sound, or controlling the start or stop of playing of the background sound. 
       Embodiment 6 
       [0071]    Referring to  FIG. 6 , for the background sound data in the background sound service system BST to be managed, the background sound providers to be able to store the data of background sound in the background sound service system BST and the subscribers of the background sound to order, modify, adjust or cancel the background sound service, a background sound data management device BSTMA is provided in the background sound service system BST. The background sound data management device BSTMA is connected to the internet and by means of which, the background sound service operators may manage the background sound service system BST and the data in it. The background sound providers store the background sound data in the background sound storage device BSTM under the control of the background sound data management device BSTMA through the Internet. The subscribers of the background sound interact with the background sound data management device BSTMA through the Internet to order, modify, adjust or cancel the background sound service. The operators of the background sound manage the background sound data through the background sound data management, device. 
         [0072]    It should be noted that the embodiments above are only for the illustration of the present invention and not intended to limit the present invention. Therefore, though the present invention has been describe in detail with reference to the embodiments above, it should be understood by those skilled in the art, that any modification or equivalent replacement may be made to the present invention without departing from the spirit and scope of the present invention that are set forth in the appended claims.