Transmitting service information without establishing a connection

The invention relates to a radio system which transmits packet traffic and to a method of transmitting service information flexibly between a network part and a terminal in a radio system which transmits packet traffic and in which a connection set-up process is activated by means of a session management arrangement when a connection is established between the terminal (402) and the network part (400). When service information is transmitted between the network part and the terminal, the party needing service activates the connection set-up process and during activation the party needing service indicates the need for service information and the quality of service with a message (602). The party providing service responds with one or more messages (606) which include service information. The connection set-up process is finished without establishing a connection. This way radio path resources can be saved.