Cordless telephone set

Abstract

Abstract 1. Cordless telephone set as well as fixed relay station which exclusively corresponds with the telephone set or with telephone sets of one subscriber station connected in parallel, for telephone calls using the public network, said telephone set as well as said relay station, which is directly connected to the telephone network, each comprising a radio transmitter and a radio receiver, and the transmitters exchanging identification signals for avoiding wrong connections, characterized in that the transmitters (4, 14) are provided with a coding device (7, 17) for generating the identification signal or -signals in order to transmit a code on a channel identified as being idle by the corresponding receiver (3, 13), the code of the transmitters (4, 14) being invariable and independent from the dialled telephone number of a subscriber station, that the receivers (3, 14) are provided with a scanner for distinguishing between free and busy channels from a plurality of present communication channels or pairs of communication channels respectively, and that a comparator (9, 19) is located after the receivers (3, 13) which seizes the transmitted invariable code and compares it with the receiver-side code, as well as a circuit to establish the cordless connection especially in duplex operation between the telephone set and the telephone relay station in case of code identity detected in the comparator (9, 19) circuit.

Inventors

• 👤 Klaus Dipl. Ing. Dr. Kerschbaumer
• 👤 Heinz Ing. Resch
• 👤 Franz Ing. Machl
• 👤 Helmut Ing. Ullrich

Bibliographic Details