The invention relates to a method for sending messages in an energy self-sufficient radio system, wherein an electric power for the radio system is provided by an energy converter that converts nonelectrical primary energy from the environment into electric power. The method comprises the steps of storage of at least two transmission channels in the radio system, presetting of a transmission unit of the radio system to a preferred stored transmission channel, checking of a use of the preferred transmission channel by other radio systems and if necessary changing from the preferred transmission channel to another stored transmission channel if the preferred transmission channel is in use, and sending of a predetermined radio message by the transmission unit on the preferred or the other transmission channel. The energy converter is excited by a mechanical operation of an operating element of the radio system, as a result of which electric power for performing the method is provided, and wherein each operation of the operating element prompts the performance of at least one portion of the above method. In addition, a reception method and also a radio system and a receiver system for performing the corresponding methods are described. One conceivable application described is an initialization method.