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This page displays all 「FI」 in main group H04K1/00. |
HB:Handbook | ||||
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CC:Concordance | |||||
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Secret communication (ciphering or deciphering apparatus per se; systems with reduced bandwidth or suppressed carrier H04B 1/66; spread spectrum techniquesH04B 1/69; by using a sub-carrier H04B 14/08; by multiplexing H04J; transmission systems for secret digital information H04L 9/00; secret or subscription television systems H04N 7/16, H04N 21/00) | HB | CC | 5J104 | |
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changing the carrier frequency | HB | CC | 5J104 | |
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Others, e.g. scramble communication | HB | CC | 5J104 | |
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.by adding a second signal to make the desired signal unintelligible | HB | CC | 5J104 | |
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.by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band | HB | CC | 5J104 | |
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.by transmitting the information or elements thereof at unnatural speeds or in jumbled order or backwards | HB | CC | 5J104 | |
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.by varying the polarisation of transmitted waves | HB | CC | 5J104 | |
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.by using two signals transmitted simultaneously or successively | HB | CC | 5J104 | |