Abstract: A system and a method for automatic establishment of a radio link for data transmission between two or more transmitter-receiver stations stores data of the frequency bands and access procedures authorized for each of the bands in a memory unit. A search receiver searches all available frequency bands. The frequency band and the access procedure are determined in an evaluation device. The address of the opposite or remote station is transmitted through the evaluation device. When the search receiver of the opposite or remote station receives its address, it switches its data receiver to "receive" in the frequency band using the appropriate access procedure, and data is subsequently transmitted between the calling station and the opposite or remote station.

Abstract: In an arrangement for suppressing spurious signals occurring in a reception signal in a receiver of a high-frequency message transmission system, these spurious signals resulting from at least one neighboring channel that neighbors the useful signal channel, the reception signal is distributed onto at least two branches. One of the branches has a summing element as well as a circuit for generating a signal with a frequency, phase and amplitude corresponding to the useful signal. The other branch also has a summing element as well as a circuit for generating a signal having a frequency, phase and amplitude corresponding to the spurious signal. The signals of these branches are respectively supplied anti-phase to the summing element of the respective other branch.

Abstract: For setting up LOS radio links between mobile calling transmitting/receiving stations and other mobile or stationary remote transmitting/receiving stations in a predetermined operating area, especially in the frequency range above 1 GHz, every mobile station is provided with an electronic memory with an associated processor. The memory stores the respective geographical and topographical data of the operating area. Prior to the setting-up of a radio link, the transmission loss between the stations is calculated in accordance with known model calculations on the basis of the geographical and topographical data stored in the memory by inputting into the processor the current location data of the calling station and the remote station.