JPS5691553A - Initial synchronization system of two-wire two-way communication - Google Patents

Initial synchronization system of two-wire two-way communication

Info

Publication number
JPS5691553A
JPS5691553A JP16973879A JP16973879A JPS5691553A JP S5691553 A JPS5691553 A JP S5691553A JP 16973879 A JP16973879 A JP 16973879A JP 16973879 A JP16973879 A JP 16973879A JP S5691553 A JPS5691553 A JP S5691553A
Authority
JP
Japan
Prior art keywords
signal
terminal
sound
synchronizing signal
initial
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP16973879A
Other languages
Japanese (ja)
Inventor
Shigeru Asakawa
Fumio Sugiyama
Makoto Nakamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP16973879A priority Critical patent/JPS5691553A/en
Publication of JPS5691553A publication Critical patent/JPS5691553A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Abstract

PURPOSE:To establish initial synchronism in two-way secret communication using a telephone line, by returning a confirmation synchronizing signal from the 2nd terminal when a synchronizing signal sent from the 1st terminal is detected. CONSTITUTION:A sound transmission signal transmitted from transmitter 3 is inputted to secrecy device 11, which performs secrecy processing according to prescribed rules to make the input into a secrecy signal. This processing is performed by digitizing the sound signal and then by performing arithmetic using a binary random-number string. Sound detecting circuit 12 detects the output of device 11 to open gate switch circuit 13 and also permits gate switch circuit 14 to cut off the sound input from hybrid circuit 2. On arrival of a dial signal at this communication terminal from another communication terminal, transmission-reception control circuit 17 operates to set device 11 in initial sunchronizm mode, and initial synchronizing signal SYNC1, transmitted at intervals of a prescribed period, is received and confirmed by another terminal, which returns synchronizing signal SYNC2 to establish synchronism at the timing of its reception.
JP16973879A 1979-12-26 1979-12-26 Initial synchronization system of two-wire two-way communication Pending JPS5691553A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16973879A JPS5691553A (en) 1979-12-26 1979-12-26 Initial synchronization system of two-wire two-way communication

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16973879A JPS5691553A (en) 1979-12-26 1979-12-26 Initial synchronization system of two-wire two-way communication

Publications (1)

Publication Number Publication Date
JPS5691553A true JPS5691553A (en) 1981-07-24

Family

ID=15891923

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16973879A Pending JPS5691553A (en) 1979-12-26 1979-12-26 Initial synchronization system of two-wire two-way communication

Country Status (1)

Country Link
JP (1) JPS5691553A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61157039A (en) * 1984-12-28 1986-07-16 Fujitsu Ltd Subscriber line transmitter

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61157039A (en) * 1984-12-28 1986-07-16 Fujitsu Ltd Subscriber line transmitter

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