The invention relates to telecommunication.

In particular, the invention relates to a new and ad- vanced method of transmitting messages containing mul- timedia information between mobile station terminals.

PRIOR ART The use of short messages in communication between mobile stations has become common for the past few years. The maximum length for a short message is up to 160 characters. The transmission of messages does not require that the mobile station is switched on. If the mobile station cannot be reached, the mes- sage is saved to the short message service centre. The short message service centre saves the message for several days, and if the mobile station receiving the message is activated in the area of the mobile net- work, then the message is sent to the mobile station.

Messages are being transmitted either in the area of the same cell or to other cells by means of the roam- ing feature of the mobile station. Typically, short messages are being transmitted in a pan-European digi- tal mobile network (GSM, Global System for Mobile Com- munications).

As known, short messages may only be used for sending messages in a text form. The quick development of technology has lead to the fact that in the near future, the consumers will be offered also a possibil- ity to the use of multimedia messages consisting of different media components. Multimedia messages have not, however, been standardized in any way, so it is apparent that the solutions to be offered are opera- tor-/device manufacturer-specific. The consequence of this is the problem that multimedia messages cannot be sent between different operators, or the transmission is going to be a difficult and expensive process.

OBJECTIVE OF THE INVENTION The objective of the present invention is to disclose a new kind of method and system that elimi- nate the drawbacks referred to above or at least sig- nificantly alleviate them. One specific objective of the invention is to present a method and a system that enable the transmission of messages containing multi- media information between different operators.

SUMMARY OF THE INVENTION In the present invention, a multimedia mes- sage is transmitted in a telecommunication network.

The created multimedia message is sent from the first mobile station terminal, is transmitted further on, a notification informing about the multimedia message that came in is sent to the receiving second mobile station terminal, and the multimedia message is re- trieved on the second mobile station terminal device.

A multimedia message is used to mean a message, which advantageously consists of several different media components, such as an image, voice, text and/or graphics.

According to the invention, a multimedia mes- sage is sent from the first mobile station terminal to the first multimedia message server using the mobile communication network, the multimedia message is saved on the first multimedia message server to the mailbox of the sender; if necessary, the address information of the second multimedia message server is found out using the first address database arranged in conjunc- tion with the first multimedia message server, an e- mail message is created based on the multimedia mes- sage, the e-mail message is transmitted from the first multimedia message server to the second multimedia message server using the IP network, a multimedia mes- sage is created based on the received e-mail message

using the second multimedia message server, the multi- media message is saved on the second multimedia mes- sage server to the mailbox of the receiver; if neces- sary, the address of the second terminal device is found out by means of the second address database ar- ranged in conjunction with the second multimedia mes- sage centre, and a notification informing about the multimedia message that came in is sent from the sec- ond multimedia message server to the second terminal device using the mobile communication network. If nec- essary, the message may also be created a mailbox of its own. Multimedia message servers may be implemented as separate units, or they may be integrated with the already existing network components, e. g. with the short message server. A digital mobile network is, e. g. a GSM network. The IP network is used to mean a telecommunication network that uses the IP protocol (Internet Protocol, IP) for data transfer. This kind of network is, e. g. the public Internet network.

In an embodiment of the invention, an e-mail message is created based on the multimedia message by coding the multimedia message in question into an e- mail message in the MIME form, e. g. in such a way that the text part to be sent is attached to serve as the plain message body and the other parts of the message are attached to the attachment part of the message.

MIME (Multipurpose Internet Mail Extensions, MIME) is a way of combining attachments to e-mail messages known in itself.

In an embodiment of the invention, informa- tion is maintained in the first address database that relates to the correlation between the DNS addresses (Domain Name Server, DNS) and MSISDN numbers (Mobile Subscriber ISDN, MSISDN) of multimedia message serv- ers.

In an embodiment of the invention, informa- tion is maintained in the second address database that

relates to the correlation between the MSISDN numbers and e-mail addresses belonging to the sphere of the second multimedia message server.

In an embodiment of the invention, a multime- dia message is sent from the first mobile station ter- minal using a browser-type user interface in the ter- minal device in question. Advantageously, this kind of browser-type user interface has been implemented using the WAP technology (Wireless Access Protocol, WAP) In an embodiment of the invention, the multi- media message is retrieved on the second mobile sta- tion terminal using a browser-type user interface in the terminal device in question. Advantageously, this kind of browser-type user interface has been imple- mented using the WAP technology.

In an embodiment of the invention, the e-mail to be transmitted is encrypted. For the encryption, an encryption method PGP (Pretty Good Privacy, PGP) known in itself may be used.

In an embodiment of the invention, the e-mail message is transmitted using the SMTP protocol (Simple Message Transfer Protocol, SMTP).

In an embodiment of the invention, a billing ticket is generated based on the multimedia message.

As compared with prior art, the present in- vention provides the advantage that it makes it possi- ble to send multimedia messages between different op- erators. Since the invention utilizes existing gener- ally known e-mail practices, the solution in accor- dance with the invention is easy to implement and widen. Further, the solution in accordance with the invention does not require the building of dedicated connections between the multimedia message servers be- cause one may use the public Internet. Due to the pos- sibility of encryption, the information security is not endangered either.

BRIEF DESCRIPTION OF THE DRAWINGS In the following section, the invention will be described by the aid of attached examples of em- bodiments with reference to the accompanying drawing, in which Fig. 1 schematically represents one system in accordance with the invention; and Fig. 2 schematically represents one method in accordance with the invention.

DEATAILED DESCRIPTION OF THE INVENTION Fig. 1 is a block diagram representing, by way of example, the components of one system in accor- dance with the invention. As shown by Fig 1, the sys- tem comprises a mobile station terminal MSA for send- ing the multimedia message, a second mobile station terminal MSB for receiving the multimedia message, and a digital mobile network GSM. According to the inven- tion, the system comprises a first multimedia message server SMSCA for saving the multimedia message, trans- forming it into an e-mail message and for sending the e-mail message in question to the second multimedia message server SMSCB, a first address database DBA for maintaining the address information of the multimedia message servers, which first address database DBA is arranged in conjunction with the first multimedia mes- sage server SMSCA, an IP network IP for transmitting the e-mail message in question from the first multime- dia message server SMSCA to the second multimedia mes- sage server SMSCB; a second multimedia message server SMSCB for transforming the received e-mail message into a multimedia message, for saving the multimedia message and for sending a notification of the multime- dia message that came in to the second terminal device MSB, and a second address database DBB for maintaining the address information of mobile subscribers belong-

ing to the sphere of the second multimedia message server SMSCB, which second address database DBB has been arranged in conjunction with the second multime- dia message server SMSCB. In addition, the system com- prises a coder MIME for coding the multimedia message into an e-mail message in the MIME form as well as an encrypting method PGP for encrypting the e-mail mes- sage to be transmitted. The first terminal device MSA comprises a browser-type user interface WAPA. In addi- tion, the second terminal device MSB comprises a browser-type user interface WAPB.

Fig. 2 is a flow chart representing, by way of example, one method in accordance with the inven- tion, by means of which method a short message is sent between two different operators via the IP network. At first, the user of the mobile station writes a short message, block 21. The short message is sent to the short message service centre, block 22. In the short message service centre, the short message is temporar- ily saved to the mailbox of the sender, block 23. A billing ticket is sent to the database, block 24. The address of the message is, e. g. of the form +358400123456@mmm. operator. com. Based on the country code of the message and the operator code, +358400, the e-mail server of the recipient becomes clear, block 25. For finding out the country code, operator code and the address of the e-mail server, a specific database is maintained in the short message service centre. The message is transmitted via the IP network to the server of the recipient, block 26. For the pe- riod of the data transfer, the multimedia information is coded by a multipurpose Internet mail extension (MIME, Multipurpose Internet Mail Extension), and for the transfer itself, a simple message transfer proto- col (STMP, Simple Message Transfer Protocol) is used.

The address of the message is being further examined on the receiving server. The receiving server is

equipped with a database using which the address of the message +358400123456@mmm. operator. com may be transformed into the form of an e-mail message of the recipient First name. Family name@mmm. operator. com, block 27. After this, the message is saved to the electronic mail box of the recipient, block 28. If there is no electronic mail box, a new electronic mail box is created. A billing ticket is created based on the message that is sent to the server that sent the message, and after this the receiver of the message is sent the whole message or a part of the message, blocks 29 and 210. The transmission type of the mes- sage is selected based on the features of the terminal device of the recipient and the network.

The invention is not restricted merely to the embodiments referred to above, instead many variations are possible within the scope of the inventive idea defined by the claims.