Methods and apparatus for push to talk type service

A method for key conversation type service. Disk (3) is invite first terminal (A) is provided with a key conversation type session's message from a terminal (B) of server (S). The information a second end (B) and during session to the media type list of the first terminal (A) transmission. Front, a first terminal (A) informs (1) server (S) following: informationOf at least media type of the media type or each media type, assigned lower parts condition, and with the electrode comprises, a terminal (A) to move of media type of the key conversation type session. A reception of invitation response message and based on the information, a server (S) inspection media type list, so that the number of omitting first terminal (A) is a to media type of the terminal (B) to move. A - comprising at least media type the list, wherein a to inspect the list invitation message to retransmit (5) is electrically connected with the first terminal. In one embodiment, invited message is session starting protocol of invitation a message, and Session Description Protocol parameter by to methods for media type list. Key conversation type service a base on the key conversation of cellular to serve (PoC). Key conversation type service can be a parliamentary service.