Abstract:
A multimedia-messaging-service (MMS) system and the service method thereof are provided. The MMS system integrates the mobility management scheme of a GSM/GPRS/UMTS mobile network and the broadband transmission service of a wireless LAN, and has a user authentication and a location management. The MMS system uses a MMS server to communicate with a wireless LAN, a GSM/GPRS/UMTS mobile network and an Internet for providing the MMS service including user registration, message submission, message forwarding, message notification, message retrieval and location update.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present relates to a multimedia messaging service (MMS) system and the service method thereof, in particular, to an MMS system and the service method thereof in which integrates mobility management mechanisms of GSM/GPRS/UMTS mobile network and wideband transmission services of wireless local area network (WLAN), and enables user authentication and location management. 
     2. Description of Related Art 
     GSM Short Messaging Service (SMS) has now become the most successful wireless data service ever since 1992. GSM short message service allows only mobile users to transfer and receive text short messages of no more than 160 characters. Accordingly, in order to create more revenue from current GSM networks, mobile phone operators promoted Enhanced Messaging Service (EMS), offering user features of enhanced messaging services for transferring and receiving combinations of texts, simple pictures and music, which can be considered as extensions of GSM short message service; that is, each enhanced short message is treated as a series of GSM short messages. Succeeding to the enhanced messaging service, era of Multimedia Messaging Service (MMS) emerges. 
     Multimedia messaging service provides message transmissions among mobile devices, as well as between applications and mobile devices, offering integral and various contents, including: texts, pictures, audio and video. Multimedia messaging system can join different networks and networks of different types, and integrate existing short messaging systems, forming the Multimedia Messaging Service Environment (MMSE). Now refer to  FIG. 1 , which illustrates a diagram of a multimedia messaging service system environment. As shown in  FIG. 1 , in a multimedia messaging service system environment  1 , a Multimedia Messaging Service Server (MMS Server)  10  joins a GSM/GPRS/UMTS mobile network  12  and Internet  14 , and integrates the short message service elements into these networks to provide user with services of multimedia messaging transmission. The GSM/GPRS/UMTS mobile network  12  comprises second generation (2G) mobile networks (e.g. GSM, GPRS) and third generation (3G) mobile networks (e.g. UMTS). In brief, the multimedia messaging service server  10  is responsible for handling multimedia messages, and takes advantage of data transmission services provided in various networks to send content-rich multimedia messaging. In addition, the multimedia messaging service server  10  also offers convergent functions between the Multimedia Messaging Service User Agent (MMS User Agent)  18  and the External Server  16 , such that various servers in different networks can be integrated. The multimedia messaging service server agent  18  provides multimedia message service user with functions for viewing, editing and processing multimedia messaging. The external server  16  is coupled to servers in various types of networks. For example, in the multimedia messaging service environment  1 , the GSM/GPRS mobile stations or UMTS user equipments consisting of the multimedia messaging service server agent  18  can utilize the mobile network services provided by the GSM/GPRS/UMTS mobile network  12 , submitting and retrieving multimedia messages via the multimedia messaging service server  10 . Besides, the GSM/GPRS mobile stations or UMTS user equipments can also receive emails from the external server  16  (e.g. email servers), or submit multimedia messaging to users of the external server  16 , through the multimedia messaging service server  10 . 
     The GSM/GPRS/UMTS mobile network  12  can actually provide data transmission rates of only 9.6/50/300 kbps, resulting in the contents which short message service can provide are not only lack of diversity, but expensive in service charge. Insufficiency of wireless bandwidth has now become one tough issue with which the GSM/GPRS/UMTS mobile network  12  is confronted for providing multimedia messaging service. Thus, in case the problem of bandwidth insufficiency can be solved, multimedia messaging service will facilitate to create a win-win result for both users and network service vendors. Among various wireless technologies currently used, wireless local are network (WLAN) is the only one which allows for wireless broadband transmission service, but, however, WLAN may not provide a good mobility management mechanism as the GSM/GPRS/UMTS mobile network  12  does. Hence, it is possible to provide mobile users with content-rich multimedia messaging service, supposing the mobility management mechanism of the GSM/GPRS/UMTS mobile network  12  and the broadband transmission service of WLAN can be well integrated. 
     Still, current mobile application services are dominated by the system operators of the GSM/GPRS/UMTS mobile network  12  to an extremely high extent; thus, if only integrating the mobility management mechanism of the GSM/GPRS/UMTS mobile network  12  and the broadband transmission service of WLAN, though being effective for multimedia messaging service provision, the business model, user authentication and user location management thereof will surely become under the control of the operators of the GSM/GPRS/UMTS mobile network  12 , which is unfavorable for other competitors to participate, furthermore adversely effecting the promotion and application of multimedia messaging service as well. Therefore, for the purpose of providing multimedia messaging service and enhancing the promotion thereof as well as application, in addition to integrating the mobility management mechanism of the GSM/GPRS/UMTS mobile network  12  and the broadband transmission service of WLAN, it is required to design a set of user authentication and location management mechanism completely independent of the GSM/GPRS/UMTS mobile network  12 . 
     SUMMARY OF THE INVENTION 
     In view of this, the present invention provides a multimedia messaging service (MMS) system and the service method thereof, wherein the purpose the present invention is to integrate the mobility management mechanism of the GSM/GPRS/UMTS mobile network and the broadband transmission service of WLAN, and to propose an authentication and location management method independent of the GSM/GPRS/UMTS mobile network, allowing to establish a WG 2 U (WLAN and GSM/GPRS/UMTS) multimedia messaging service system having the following features: 
     1. Instant messaging notification: WG 2 U multimedia messaging service users will receive instantaneously notification for message arrival, relevant information of notification message, including: sender&#39;s address, message subject, class, size, priority and media type etc. 
     2. Content-rich and high-speed messaging access: WG 2 U multimedia messaging service users can rapidly submit and retrieve multimedia messaging with integral and diverse contents, including: texts, pictures, audio, video and the like. 
     3. Convergent messaging service: WG 2 U multimedia messaging service users can receive messaging from various types of servers, and submit messaging to thereto as well, including: email server, voice box server and so on. 
     4. Operator-independent user management: WG 2 U multimedia messaging service system offers user authentication and location management method independent of GSM/GPRS/UMTS mobile network, allowing business operations of multimedia messaging service, without restrictions from GSM/GPRS/UMTS mobile network system operators. 
     In summary, the multimedia messaging service system provided by the present invention can join a WG 2 U multimedia messaging service server (WG 2 U MMS Server), a wireless local area network (WLAN), a GSM/GPRS/UMTS mobile network and Internet. The multimedia messaging service system provided by the present invention takes advantage of features from WLAN and GSM/GPRS/UMTS mobile network, offering multimedia messaging service meeting users&#39; expectation, i.e. efficient, low-cost as well as content-rich multimedia messaging service. 
     Furthermore, multimedia messaging service users can use WG 2 U multimedia messaging service user agent (WG 2 U MMS User Agent) to process multimedia messaging, including: editing, submitting, retrieving, viewing, forwarding, deleting, saving. Besides, the WG 2 U multimedia messaging service user can also use WG 2 U multimedia messaging service user agent to, via the WG 2 U multimedia messaging service server, submit multimedia messaging to external servers, or receive various messages from external servers. External servers are servers coupled with different networks, comprising: email server, voice mail server, multimedia messaging service server from different operators. 
     In addition to multimedia messaging process functions, WG 2 U multimedia messaging service system also offers user authentication and location management independent of GSM/GPRS/UMTS mobile network. WG 2 U multimedia messaging service user authentication and location management comprises: registration procedure and location update procedure. By means of registration procedure, WG 2 U multimedia messaging service users first acquire authentication and authorization from WG 2 U multimedia messaging service server, then commence to use services provided by WG 2 U multimedia messaging service system. Furthermore, when the location of a WG 2 U multimedia messaging service user changes, it is possible to obtain services from the local WG 2 U multimedia messaging service server by means of location update procedure, reducing network transmission time and accelerating submission and retrieval of multimedia messaging. 
     Aforementioned summary as well as succeeding detail description are merely exemplary, which aim to further illustrate the claims of the present invention. Whereas other objects and advantages of the present invention will be construed in the following Description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description of the drawings: 
         FIG. 1  illustrates a diagram of a multimedia messaging service system environment; 
         FIG. 2  illustrates a multimedia messaging service system architecture diagram of the present invention; 
         FIG. 3  illustrates a flowchart for the registration method in the multimedia messaging service of the present invention; 
         FIG. 4  illustrates a flowchart for the messaging submission method in the multimedia messaging service of the present invention; 
         FIGS. 5A and 5B  illustrate a flowchart for messaging forwarding method of the multimedia messaging service of the present invention; 
         FIG. 6  illustrates a flowchart for the messaging notification method in the multimedia messaging service of the present invention; 
         FIGS. 7A and 7B  illustrate a flowchart for messaging retrieval method of the multimedia messaging service of the present invention; and 
         FIG. 8A to 8C  illustrate flowcharts of the user location update method in the multimedia messaging service of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 2 , wherein is shown a multimedia messaging service system architecture diagram of the present invention. The multimedia messaging service system  2  of the present invention provides a multimedia messaging service user (not shown) messaging-related service, in which the multimedia messaging service system  2  comprises: a multimedia messaging service server  20 , a wireless local area network  21 , a GSM/GPRS/UMTS mobile network  22 , Internet  24 , an external server  26  and a multimedia messaging service user agent  28 . 
     In  FIG. 2 , the multimedia messaging service user agent  28  is installed in the multimedia messaging service user, and the multimedia messaging service user uses the multimedia messaging service user agent  28  to connect in communication the wireless local area network  21  and the GSM/GPRS/UMTS mobile network  22 . The multimedia messaging service server  20  connects in communication the wireless local area network  21  and the GSM/GPRS/UMTS mobile network  22 , and the multimedia messaging service server  20  can perform a user registration procedure, a messaging submission procedure, a messaging forwarding procedure, a messaging notification procedure, a messaging retrieval procedure and a user location update procedure. The Internet  24  connects in communication with the multimedia messaging service server  20 , and the multimedia messaging service server  20  can link with a visited external server through the Internet  24 . 
     In  FIG. 2 , the multimedia messaging service server  20  can provide the multimedia messaging service user with services such as messaging submission, messaging forwarding, messaging notification, messaging retrieval through the wireless local area network  21 , the GSM/GPRS/UMTS mobile network  22  and the Internet  24 . 
     In addition to multimedia messaging process function, the multimedia messaging service system  2  of the present invention also offers user authentication and location management functions independent of the GSM/GPRS/UMTS mobile network  22 . The functions of the multimedia messaging service user authentication and location management of the present invention comprise: registration procedure and location update procedure. By means of registration procedure, the multimedia messaging service user first acquires authentication and authorization from the multimedia messaging service server  20 , then commences to use messaging-related services provided by the multimedia messaging service system  2  of the present invention. Furthermore, when the location of the multimedia messaging service user changes, it is possible to obtain services from the home multimedia messaging service server  20  by means of location update procedure, reducing network transmission time and accelerating submission and retrieval of multimedia messaging. 
     In accordance with  FIG. 2 , refer to  FIG. 3 , wherein a flowchart of registration method of the inventive multimedia messaging service is shown. In the multimedia messaging service system  2 , the home multimedia messaging service server  20  is responsible for administration and maintenance of multimedia messaging service users, comprising: authentication, server authorization, location update, service charging. Before starting to use services provided by the multimedia messaging service system  2 , the multimedia messaging service user is required to use the multimedia messaging service user agent  28  to perform registration procedure, in order to acquire the authentication and service authorization from the home multimedia messaging service server  20 . 
       FIG. 3  illustrates the flowchart of registration procedure for a multimedia messaging service user, whose registration steps are shown as below: initially, multimedia messaging service user uses the multimedia messaging service user agent  28  to execute Explicit_Login request procedure through the wireless local area network  21 , requesting to log in the home multimedia messaging service server  20  (S 10 ). Such a request comprises the following parameters: account, password and phone number (MSISDN) of the multimedia messaging service user. Next, the home multimedia messaging service server  20  verifies the account and password of the multimedia messaging service user, and determines if there are sufficient resources for serving the multimedia messaging service user. After user verification and resource determination, the home multimedia messaging service server  20  performs Explicit_Login response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  whether having successfully logged into the multimedia messaging service system  2  and completed registration (S 12 ). 
     In accordance with  FIG. 2 , refer to  FIG. 4 , wherein a flowchart of messaging submission method of the inventive multimedia messaging service is shown. After the multimedia messaging service user having completed the registration procedure and acquired the service authorization from the home multimedia messaging service server  20 , the multimedia messaging service user can use the multimedia messaging service user agent  28  to request multimedia messaging submission from the home multimedia messaging service server  20 . 
       FIG. 4  illustrates the flowchart of messaging submission procedure for a multimedia messaging service user, whose steps are shown as below: initially, the multimedia messaging service user agent  28  executes Submission request procedure via the wireless local area network  21 , requesting the home multimedia messaging service server  20  to submit messaging (S 20 ). Such a request comprises the following parameters: names of sender and receiver, phone number (MSISDN), messaging contents, messaging class, messaging capacity, messaging transfer priority, messaging legal period, and whether to reply transfer report or read note being requested. Next, after the home multimedia messaging service server  20  receives the request for messaging submission, it determines each parameter of the submission request to decide if to perform messaging submission or not. After the determination, the home multimedia messaging service server  20  executes Submission response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  if to accept messaging submission request (S 22 ). Additionally, if this multimedia messaging service server  20  is not the home multimedia messaging service server of the messaging receiver, then this multimedia messaging service server  20  will perform procedure for forwarding the messaging to the home multimedia messaging service server of the messaging receiver. 
     In accordance with  FIG. 2 , refer to  FIGS. 5A and 5B , wherein a flowchart of messaging forwarding method of the inventive multimedia messaging service is shown. The home multimedia messaging service server  20  provides the function of messaging convergence, which is, multimedia messaging service user can receive messages from various servers, and submit messages to various servers as well, including email servers, voice mail servers, multimedia messaging service servers from different operators. Messaging convergence function can be achieved by means of messaging forwarding procedure. There are two cases for the messaging forwarding procedure: (A) forwarding messages from the home multimedia messaging service server  20  to the external server  26 ; (B) forwarding messages from the external server  26  to the home multimedia messaging service server  20 . 
       FIG. 5A  discloses a messaging forwarding flowchart for forwarding messaging from the home multimedia messaging service server  20  to the external server  26 . The forwarding steps are: initially, the multimedia messaging service user requests from the home multimedia messaging service server  20  through the wireless local area network  21  to submit messaging to a user of the external server  26 ; next, the home multimedia messaging service server  20  will convert the messaging according to the format appointed by the external server  26 , and executes Forward_External request procedure via the Internet  24 , sending the name of the receiver (e.g. mail address) and contents of the message to the external server  26  (S 30 ); upon the reception of the messaging, the external server  26  executes Forward_External response through the Internet  24 , notifying the home multimedia messaging service server  20  the status of the messaging reception (S 32 ). 
       FIG. 5B  discloses a messaging forwarding flowchart for forwarding messaging from the external server  26  to the home multimedia messaging service server  20 . The forwarding steps include: initially, the user of the external server  26  requests to send messaging to the multimedia messaging service user, then the external server  26  will execute Forward_MMS request procedure through the Internet  24 , sending the name of the receiver (e.g. email address or phone number (MSISDN)) and the contents of the messaging to the home multimedia messaging service server  20  (S 31 ); next, the home multimedia messaging service server  20  will execute Forward_MMS response procedure via the Internet  24 , notifying the external server  26  the status of reception (S 33 ). Besides, after that the home multimedia messaging service server  20  successfully received the forwarded messaging, it will find out the corresponding phone number (MSISDN) according to the name of the receiver, notifying the multimedia messaging service user to retrieve the messaging. 
     In accordance with  FIG. 2 , refer to  FIG. 6 , wherein a flowchart of messaging notification method of the inventive multimedia messaging service is shown. Upon that the home multimedia messaging service server  20  agreed the request of messaging submission from multimedia messaging service user, if the receiver of the messaging is also one another multimedia messaging service user served by the home multimedia messaging service server  20 , then the home multimedia messaging service server  20  will execute messaging notification procedure to notify the other multimedia messaging service user retrieving the messaging. 
     Additionally, if the home multimedia messaging service server  20  received the messaging forwarded from the external server  26 , it will also activate the messaging notification procedure.  FIG. 6  discloses the notification method workflow of the inventive multimedia messaging, whose steps include: initially, the home multimedia messaging service server  20  executes the Notification request procedure in accordance with the receiver&#39;s phone number (MSISDN) through the GSM/GPRS/UMTS mobile network  22 , sending a messaging notification to the multimedia messaging service user agent  28  of the receiver (S 40 ). This messaging notification comprises: name of the sender, submission date and time, messaging title, messaging class, messaging capacity, messaging legal period and identification number. Next, upon the multimedia messaging service user agent  28  received the messaging notification, it will execute the Notification response procedure through the wireless local area network  21 , notifying the home multimedia messaging service server  20  if the messaging notification has been successfully received (S 42 ). 
     In accordance with  FIG. 2 , refer to  FIGS. 7A and 7B , wherein a flowchart of messaging retrieval method of the inventive multimedia messaging service is shown. The home multimedia messaging service server  20  is responsible for the storage of the messaging. When the multimedia messaging service user is located in the service range of the home multimedia messaging service server  20 , in case messaging retrieval is required, it will execute the procedure for retrieving messaging from the home multimedia messaging service server  20 , as shown in  FIG. 7A , in order to retrieving messaging from the local server  20 . 
     But, when the multimedia messaging service user is located outside of the service range of the home multimedia messaging service server  20 , when messaging retrieval is required, it will execute a procedure for retrieving messaging from the visited multimedia messaging service server (not shown), as illustrated in  FIG. 7B , wherein the visited multimedia messaging service server in which the multimedia messaging service user is currently located will first acquire the messaging saved in the home multimedia messaging service server  20 , then send the messaging to the multimedia messaging service user. 
     Refer to  FIG. 7A , wherein disclosed the procedure of messaging retrieval for the multimedia messaging service user from the home multimedia messaging service server, whose steps are listed as below: initially, the multimedia messaging service user executes Retrieval request procedure by means of the multimedia messaging service user agent  28  through the wireless local area network  21 , requesting messaging retrieval from the home multimedia messaging service server  20  (S 50 ). Such a request comprises the following parameters: identification number of the messaging and name of the multimedia messaging service user. Next, the home multimedia messaging service server  20  finds out the messaging that the multimedia messaging service users would like to view, and executes the Retrieval response procedure via the wireless local area network  21 , sending the messaging to the multimedia messaging service user agent  28  (S 52 ). Then the multimedia messaging service user agent  28  executes the Retrieval_Ack request procedure through the wireless local area network  21 , notifying the home multimedia messaging service server  20  if the messaging has been successfully retrieved (S 54 ). 
     Refer to  FIG. 7B , wherein disclosed the procedure of messaging retrieval for the multimedia messaging service user from the visited multimedia messaging service server, whose steps comprise: initially, the multimedia messaging service user executes Retrieval request procedure by means of the multimedia messaging service user agent  28  through the wireless local area network  21 , requesting the messaging retrieval from the visited multimedia messaging service server (S 51 ). Such a request comprises the following parameters: identification number of the messaging and phone number (MSISDN) of the multimedia messaging service user. Next, upon reception of such request, the visited multimedia messaging service server will execute the Retrieval_Forward request procedure via the Internet  24  in accordance with the identification number of the messaging, phone number of the multimedia messaging service user and the address of the home multimedia messaging service server  20 , requesting the home multimedia messaging service server  20  to forward the messaging that the multimedia messaging service user wants to view (S 53 ). 
     Then, the home multimedia messaging service server  20  finds out the messaging the multimedia messaging service users would like to view according to the identification number of the messaging, and executes the Retrieval_Forward response procedure via the wireless local area network  24 , forwarding the messaging to the visited multimedia messaging service server (S 55 ). Furthermore, the visited multimedia messaging service server executes the Retrieval response procedure through the wireless local area network  21 , sending the multimedia messaging to the multimedia messaging service user agent  28  (S 57 ). Then the multimedia messaging service user agent  28  executes the Retrieval_Ack request procedure through the wireless local area network  21 , notifying the visited multimedia messaging service server if the messaging has been successfully received (S 58 ). Finally, the visited multimedia messaging service server executes Retrival_Ack_Forward request through the Internet  24 , informing the home multimedia messaging service server  20  of the status of messaging retrieval (S 59 ). 
     In accordance with  FIG. 2 , refer to  FIG. 8A to 8C , wherein a flowchart of the user location update method of the inventive multimedia messaging service is shown. When the multimedia messaging service user is roaming from the service range of one home multimedia messaging service server  20  to the service range of another multimedia messaging service server (not shown), the multimedia messaging service user agent  28  will automatically execute the location update procedure, acquiring the services of the multimedia messaging service server in which the user currently located, reducing network transmission time and accelerating multimedia messaging submission and retrieval. According to the moves of the multimedia messaging service user, three possible situations might occur to the user location update procedure: (A) moving from the home multimedia messaging service server  20  to a visited multimedia messaging service server (as shown in  FIG. 8A ); (B) moving from a visited multimedia messaging service server to the home multimedia messaging service server  20  (as shown in  FIG. 8B ); (C) moving from one visited multimedia messaging service server to another visited multimedia messaging service server (as shown in  FIG. 8C ). 
     Refer to  FIG. 8A , wherein the location update procedure for the multimedia messaging service user when moving from the service range of the home multimedia messaging service server to the service range of the visited multimedia messaging service server is disclosed, whose steps comprise: initially, the multimedia messaging service user agent  28  executes the Alive request procedure through the wireless local area network  21 , allowing the home multimedia messaging service server  20  to determine the current location of the multimedia messaging service user by means of the IP address in the connection information (S 600 ), and to decide if to activate location update procedure based on this location information. Next, to determine if the multimedia messaging service user is located in the service range of the home multimedia messaging service server  20 ; if yes, then the home multimedia messaging service server  20  executes the Alive response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  that it is allowed to continue to use the multimedia messaging service, and the execution of the location update procedure ends. 
     Contrarily, in case the multimedia messaging service user is located in the service range of the visited multimedia messaging service server, then the home multimedia messaging service server  20  will execute the Alive response procedure via the wireless local area network  21 , informing the multimedia messaging service user agent  28  of the IP address of the visited multimedia messaging service server as well as the temporary password of the multimedia messaging service user (S 602 ). Upon appreciating the IP address of the visited multimedia messaging service server, the multimedia messaging service user agent  28  executes the Implicit_Login request procedure through the wireless local area network  21 , requesting to log in the visited multimedia messaging service server (S 604 ). This request comprises the following parameters: account, temporary password and phone number (MSISDN) of the multimedia messaging service user. 
     If there are sufficient system resources for serving the multimedia messaging service user about to log in, then the visited multimedia messaging service server will execute Update request procedure through the Internet  24 , requesting the home multimedia messaging service server  20  to authenticate the account and password (S 606 ). This request comprises the following parameters: account, temporary password and phone number (MSISDN) of the multimedia messaging service user. Following this, the home multimedia messaging service server  20  executes the Update response procedure via the Internet  24 , informing the visited multimedia messaging service server of the authentication result concerning the multimedia messaging service user, meanwhile the home multimedia messaging service server  20  updates accordingly the location information of the multimedia messaging service user (S 608 ). Finally, the visited multimedia messaging service server executes Implicit_Login response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  whether the multimedia messaging service user can login and use the multimedia messaging services (S 610 ). 
     Refer to  FIG. 8B , wherein the location update procedure for the multimedia messaging service user when moving from the service range of the visited multimedia messaging service server to the service range of the home multimedia messaging service server is disclosed, whose steps comprise: initially, the multimedia messaging service user agent  28  executes the Alive request procedure through the wireless local area network  21 , allowing the visited multimedia messaging service server to determine the current location of the multimedia messaging service user by means of the IP address in the connection information (S 601 ), and to decide if to activate location update procedure based on this location information. Next, to determine if the multimedia messaging service user is located in the service range of the visited multimedia messaging service server; if yes, then the visited multimedia messaging service server executes the Alive response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  that it is allowed to continue to use the multimedia messaging service (S 603 ), and the execution of the location update procedure ends. 
     Contrarily, since the visited multimedia messaging service server only appreciates the multimedia messaging service user is already not in its service range, but no idea about the server address within which the multimedia messaging service user currently located; hence, via the Internet  24 , the Alive_Forward request will be executed to inquire the server address at which location the multimedia messaging service user currently located from the home multimedia messaging service server  20  (S 605 ). This inquiry comprises the following parameters: IP address, temporary password and phone number (MSISDN) of the multimedia messaging service user. After authentication of password, the home multimedia messaging service server  20  updates the location information about the multimedia messaging service user, meanwhile, the home multimedia messaging service server executes the Alive_Forward response procedure through the Internet  24 , informing the visited multimedia messaging service server that the multimedia messaging service user is located in the service range of the home multimedia messaging service server  20  (S 607 ). Finally the visited multimedia messaging service server executes the Alive response procedure via the wireless local area network  21 , forwarding the address of the home multimedia messaging service server  20  to the multimedia messaging service user agent  28 , then the multimedia messaging service user can start to use services provided by the home multimedia messaging service server  20  (S 609 ). 
     Refer to  FIG. 8C , wherein the location update procedure for the multimedia messaging service user when moving from the service range of one visited multimedia messaging service server to the service range of another visited multimedia messaging service server is disclosed, whose steps comprise: initially, the multimedia messaging service user agent  28  executes the Alive request procedure through the wireless local area network  21 , allowing the visited multimedia messaging service server to determine the current location of the multimedia messaging service user by means of the IP address in the connection information (S 700 ), and to decide if to activate location update procedure based on this location information. Next, to determine if the multimedia messaging service user is located in the service range of the visited multimedia messaging service server; if yes, then the visited multimedia messaging service server executes the Alive response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  that it is allowed to continue to use the multimedia messaging service (S 702 ), and the execution of the location update procedure ends. 
     Contrarily, since the visited multimedia messaging service server only appreciates the multimedia messaging service user is already not in its service range, but no idea about the server address within which the multimedia messaging service user currently located; hence, via the Internet  24 , the Alive_Forward request procedure will be executed to inquire the server address within which the multimedia messaging service user currently located from the home multimedia messaging service server  20  (S 704 ). This inquiry comprises the following parameters: IP address, temporary password and phone number (MSISDN) of the multimedia messaging service user. After the password authentication, the home multimedia messaging service server  20  determines, according to the IP address of the multimedia messaging service user, the current location of the multimedia messaging service user is located in the service range of another visited multimedia messaging service server. Next, the home multimedia messaging service server  20  executes Alive_Forward response procedure via the Internet  24 , notifying the visited multimedia messaging service server that the multimedia messaging service user is located in the service range of another visited multimedia messaging service server (S 706 ). Following this, the visited multimedia messaging service server executes Alive response procedure through the wireless local area network  21 , forwarding the IP address of another visited multimedia messaging service server to the multimedia messaging service user agent  28  (S 708 ). 
     Upon appreciating the IP address of another visited multimedia messaging service server, the multimedia messaging service user agent  28  executes the Implicit_Login request procedure through the wireless local area network  21 , requesting to log in the other visited multimedia messaging service server (S 710 ). This request comprises the following parameters: account, temporary password and phone number (MSISDN) of the multimedia messaging service user. If there are sufficient system resources for serving the multimedia messaging service user about to log in, then another visited multimedia messaging service server will execute Update request procedure through the Internet  24 , requesting the home multimedia messaging service server  20  to authenticate the account and password (S 712 ). This request comprises the following parameters: account, temporary password and phone number (MSISDN) of the multimedia messaging service user. Following this, the home multimedia messaging service server  20  executes the Update response procedure via the Internet  24 , informing another visited multimedia messaging service server of the authentication result concerning the multimedia messaging service user, meanwhile the home multimedia messaging service server  20  updates accordingly the location information of the multimedia messaging service user (S 714 ). Finally, another visited multimedia messaging service server executes Implicit_Login response procedure through the wireless local area network  21 , notifying the multimedia messaging service user agent  28  whether the multimedia messaging service user can login and use the multimedia messaging services (S 716 ). 
     In summary of the aforementioned discussions, the multimedia messaging service system of the present invention uses the multimedia messaging service server  20  to connect in communication with the wireless local area network  21 , the GSM/GPRS/UMTS mobile network  22  and the Internet  24 , realizing the procedures of user registration, messaging submission, messaging forwarding, messaging notification, messaging retrieval and location update, with a view to construct the WG 2 U (WLAN and GSM/GPRS/UMTS) multimedia messaging service system consisting of the following features: 
     1. Instant messaging notification: WG 2 U multimedia messaging service users will receive instantaneously notification for message arrival, relevant information of notification message, including: sender&#39;s address, message subject, class, size, priority and media type etc. 
     2. Content-rich and high-speed messaging access: WG 2 U multimedia messaging service users can rapidly submit and retrieve multimedia messaging with integral and diverse contents, including: texts, pictures, audio, video and the like. 
     3. Convergent messaging service: WG 2 U multimedia messaging service users can receive messaging from various types of servers, and submit messaging to thereto as well, including: email server, voice box server and so on. 
     4. Operator-independent user management: WG 2 U multimedia messaging service system offers user authentication and location management method independent of GSM/GPRS/UMTS mobile network, allowing business operations of multimedia messaging service, without restrictions from GSM/GPRS/UMTS mobile network system operators. 
     However, the above-mentioned illustrations merely represent the detailed descriptions and drawings for one of the preferred embodiments of the present invention, and any one skilled in field of the art can easily consider the variations or modifications encompassed by spirit and range of the following claims of the application.