| 摘要 |
For avoiding the transmission of coded servicing signals on a transmission path between transmitting and receiving ends of a binary coded ciphered signal syste, each ciphered signal is formed, at the transmitting end, by first ciphering, in the sequence of the plain alphabet signals, a number of successive intelligence periods lower than the lower number of such period in any plain signal, and thereafter completing said lower number of ciphered periods up to said normal number by adding at least one additional intervening arbitrary period distinguishing the thus built up signal from any servicing signal pattern in the system. The additional arbitrary periods are canceled at the receiving end and the uncanceled periods are regrouped for normal deciphering operations. |
