| 摘要 |
In a telephone connection which can also comprise wireless sections, speech encoding devices (18, 19) are looped into the end points, at least for these wireless sections. They are equipped with signal analysers (29, 22) which respond to audio frequency signals and can influence these encoding devices, for example switching between clear and scrambled operation. An audio frequency signal generator (23 to 25 and 26 to 28), which can be acoustically coupled to the microphones of the telephone stations (1 to 3 and 6 to 8), is used for remotely controlling the encoding devices mentioned from any telephone station as required. The signal transmitter is electrically independent of the telephone network, it is not station-related but person-related which results in great flexibility with minimum complexity. <IMAGE> |
