A method in a communication system, a communication system and a communication device wherein in the method media streams are transmitted from a sending communication device to a receiving communication device at least partly via a wireless communication network. At least one media stream is selected to be transmitted to the receiving communication device. QoS requirements for transmitting the selected at least one media stream are defined, transmission resources are reserved from the wireless communication network for the transmission of at least one media stream, and a setup procedure is performed between the receiving communication device and the sending communication device for activating the one packet data transmission connection.