Method and apparatus for transmitting media data

1. A method of transmitting media data from a first communication session and media data from a second communication session, wherein a communication terminal participates in the first communication session and in the second communication session, the method comprising:

receiving the media data from the first communication session and the media data from the second communication session by a unit in the communication network, wherein each of the first communication session and the second communication session is a half-duplex communication session;

combining, based on prescribed and stored combination rules, the media data in the unit in the communication network to form at least one combined media data stream which contains media data of a media data type from the first communication session and the media data of the media data type from the second communication session; and

transmitting the at least one combined media data stream to the communication terminal, so that media data from different communication sessions are sent to the communication terminal,

wherein the combination rules are prescribed by a subscriber on the communication terminal and stored in a file of a memory located in a server, and

wherein the prescribed and stored combination rules indicate, for each type of media data, the media data from which of the first communication session and the second communication session is to be combined.

2. The method according to claim 1 , further comprising producing and transmitting to the communication terminal a respective combined media data stream per medium.

3. The method according to claim 1 , wherein each of the first communication session and the second communication session is a push-to-talk communication session.

4. The method according to claim 3 , wherein each of the first communication session and the second communication session is a push-to-talk over cellular communication session.

5. The method according to claim 4 , wherein the unit in the communication network is a push-to-talk over cellular participating server unit.

6. The method according to claim 1 , wherein each of the first communication session and the second communication session is an Internet-based communication session.

7. The method according to claim 1 , further comprising transmitting the at least one combined media data stream via a mobile radio interface to the communication terminal.

8. The method according to claim 1 , further comprising:

setting up, between the unit and the communication terminal, at least one useful data communication link and at least one control data communication link, respectively, for each communication session;

transmitting the useful data using only one useful data communication link from a plurality of useful data communication links; and

transmitting communication-session-specific control data using the respective control data communication link for the communication session to which the respective control data relate.

9. The method according to claim 1 , further comprising:

setting up, between the unit and the communication terminal, at least one useful data communication link for a plurality of communication sessions and at least one respective control data communication link for each communication session;

transmitting the useful data using the useful data communication link; and

transmitting communication-session-specific control data using the respective control data communication link for the communication session to which the respective control data relate.

10. A communication network unit transmitting media data from a first communication session and media data from a second communication session, wherein a communication terminal participates in the first communication session and in the second communication session, the communication network unit comprising:

a receiver receiving media data from the first communication session and media data from the second communication session, wherein each of the first communication session and the second communication session is accomplished according to a half-duplex communication session protocol;

a media data combiner combining, based on prescribed and stored combination rules, the media data to form at least one combined media data stream which contains media data of a media data type from the first communication session and media data of the media data type from the second communication session; and

a transmitter transmitting the at least one combined media data stream to the communication terminal, so that media data from different communication sessions are transmitted to the communication terminal,

wherein the combination rules are prescribed by a subscriber on the communication terminal and stored in a file of a memory located in a server, and

wherein the prescribed and stored combination rules indicate, for each type of media data, the media data from which of the first communication session and the second communication session is to be combined.

11. The communication network unit according to claim 10 , wherein the media data combiner produces a respective combined media data stream per medium.

12. The communication network unit according to claim 10 , which communicates based on a push-to-talk communication session protocol.

13. The communication network unit according to claim 12 , which communicates based on a push-to-talk over cellular communication session protocol.

14. The communication network unit according to claim 13 , set up as a push-to-talk over cellular participating server unit.

15. The communication network unit according to claim 10 , which communicates based on an Internet-based communication session protocol.

16. The communication network unit according to claim 10 , further comprising:

a communication link setup unit which respectively sets up a useful data communication link and a control data communication link to the communication terminal for each communication session,

wherein the transmitter transmits the useful data using only one useful data communication link from a plurality of useful data communication links; and

wherein the transmitter transmits communication-session-specific control data using the respective control data communication link for the communication session to which the respective control data relate.

17. The communication network unit according to claim 10 , further comprising:

a communication link setup unit which sets up a common useful data communication link for a plurality of communication sessions and sets up a respective control data communication link to the communication terminal for each communication session,

wherein the transmitter transmits the useful data using the common useful data communication link, and

wherein the transmitter transmits communication-session-specific control data using the respective control data communication link for the communication session to which the respective control data relate.

18. A processor executing a computer program element for transmitting media data from a first communication session and media data from a second communication session, wherein a communication terminal participates in the first communication session and in the second communication session, which comprises instructions that make the processor perform:

receiving the media data from the first communication session and of the media data from the second communication session by a unit in the communication network, wherein each of the first communication session and the second communication session is a half-duplex communication session;

combining, based on prescribed and stored combination rules, the media data in the unit in the communication network to form at least one combined media data stream which contains media data of a media data type from the first communication session and the media data of the media data type from the second communication session; and

transmitting the at least one combined media data stream to the communication terminal, so that media data from different communication sessions are sent to the communication terminal,

wherein the combination rules are prescribed by a subscriber on the communication terminal and stored in a memory located in a server, and

wherein the prescribed and stored combination rules indicate, for each type of media data, the media data from which of the first communication session and the second communication session is to be combined.

19. A communication network unit transmitting media data from a first communication session and media data from a second communication session, wherein a communication terminal participates in the first communication session and in the second communication session, the communication network unit comprising:

a receiving means for receiving media data from the first communication session and media data from the second communication session, wherein each of the first communication session and the second communication session is accomplished according to a half-duplex communication session protocol;

a media data combining means for combining, based on prescribed and stored combination rules, the media data to form at least one combined media data stream which contains media data of a media data type from the first communication session and media data of the media data type from the second communication session; and

a transmitter means for transmitting the at least one combined media data stream to the communication terminal, so that media data from different communication sessions are transmitted to the communication terminal,

wherein the combination rules are prescribed by a subscriber on the communication terminal and stored in a file of a memory located in a server, and

wherein the prescribed and stored combination rules indicate, for each type of media data, the media data from which of the first communication session and the second communication session is to be combined.