A multiplex audio signal from an exchange apparatus is demultiplexed by a first multiplexer/demultiplexer into demultiplexed signals that are supplied to a first switch circuit which switches between transmission paths to apply the demultiplexed signals to a plurality of audio coding circuits. Certain...http://www.google.fr/patents/US5425031?utm_source=gb-gplus-shareBrevet US5425031 - Mobile radio communication system
