GB1448272A - Data transmission systems - Google Patents
Data transmission systemsInfo
- Publication number
- GB1448272A GB1448272A GB4127473A GB4127473A GB1448272A GB 1448272 A GB1448272 A GB 1448272A GB 4127473 A GB4127473 A GB 4127473A GB 4127473 A GB4127473 A GB 4127473A GB 1448272 A GB1448272 A GB 1448272A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signal
- unit
- binary
- synchronizing
- switch
- 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.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
- H04K1/00—Secret communication
- H04K1/02—Secret communication by adding a second signal to make the desired signal unintelligible
Abstract
1448272 Monitoring and synchronizing secret communication systems SIEMENS AG 3 Sept 1973 [23 Nov 1972] 41274/73 Heading H4L A secret communication system in which a transmitting station is associated with one or more receiving stations includes, in each of the latter, a device for detecting faulty deciphering and operative, on occurrence of a criterion signifying faulty deciphering, to cause the receiving station cipher generator to be reset in accordance with a setting-up signal in the received signal. As described, the system employs a radio relay link, or the phase modulator of a radio link, or the line equipment section of a transmission line 21 to act as a link unit 17 in which a binary ciphered signal GTS is converted into a form suitable for transmission in terms of amplitude or phase, but the unit 17 may be replaced by a direct connection between the transmitter and each receiver. For transmission of telephone conversations, input channels K1 ... Kn are connected to a plain-language unit 15 utilizing pulse code modulation and operating on the time-division multiplex principle. In unit 15, channels K1 ... Kn pass to A-D converter 1 supplied with a bit train T from pulse generator 2 and frame synchronizing signals from a frame pulse generator 3. The binary plain-language signal KTS passes to an enciphering unit 16 where it is converted, in encoder 6 to the ciphered signal GTS, e.g. by modulo-2 addition with a binary cipher signal from cipher generator 5. The ciphered signal GTS passes to one input terminal of a changeover switch 7 to whose other input terminal an output carrying synchronizing information from a synchronizing device 6 is supplied. The switch 7 normally connects the encoder output directly to the link unit 17. but is moved, at intervals, to connect the synchronizing signals from device 6 to the unit 17. The device 6 receives, from the cipher generator 5, its particular setting information so that when switch 7 is in its last-mentioned state, the setting information is transmitted. This is preferably preceded by a short pulse train in Barker code derived from device 6. At the receiver a link unit 18 (corresponding to transmitter link unit 17) recovers the bit train T (from its section 18<SP>1</SP>) and passes the received enciphered binary signal GTE to decoder 8, e.g. modulo-2 adder receiving a binary cipher signal from cipher generator 9. Plain-language binary text KTE is supplied from the decoder 8 to D-A converter 10 which distributes the signal between output channels K1<SP>1</SP> ... Kn<SP>1</SP>. The frame synchronizing signal required for the D-A conversion and resolution of the TDM-frame is supplied from a unit 11, the frame synchronizing signal from unit 11 also being compared (in a synchronism monitor section of unit 11) with the binary plain-language signal KTE. If the frame synchronizing signal in the received signal KTE corresponds with that generated locally in unit 11, correct deciphering is assumed; but, if there is a lack of correspondence a change-over switch 13 is operated to connect an analyser unit 12 to the output of link unit 18. The unit 12 includes a circuit which responds to reception of the Barker code signal to prepare the unit for the reception of the transmitted setting information. When the latter is received, unit 12 relays it directly to cipher generator 9 to reset the same whereby synchronism is restored and switch 13 returned to its normal position. The switch 7 at the transmitter may be operated to pass setting-up signals from the synchronizing device 6 at regular intervals, e.g. after each second or third pulse frame or, alternatively, only at those instants when, as a function of the plain-language signal being transmitted, there are gaps in the information flow. It is also possible for a return line 14 to be provided between the receiver and transmitter whereby demand information, calling for transmission of the setting-up signal, can be sent to the transmitter.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19722257361 DE2257361C1 (en) | 1972-11-23 | 1972-11-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1448272A true GB1448272A (en) | 1976-09-02 |
Family
ID=5862482
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB4127473A Expired GB1448272A (en) | 1972-11-23 | 1973-09-03 | Data transmission systems |
Country Status (9)
Country | Link |
---|---|
BE (1) | BE805334A (en) |
CA (1) | CA1023486A (en) |
DE (1) | DE2257361C1 (en) |
DK (1) | DK146989B (en) |
FR (1) | FR2296974A1 (en) |
GB (1) | GB1448272A (en) |
IT (1) | IT1001671B (en) |
NL (1) | NL156877B (en) |
NO (1) | NO137802C (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2719545C1 (en) * | 2019-05-14 | 2020-04-21 | Федеральное государственное казенное военное образовательное учреждение высшего образования "Военный учебно-научный центр Военно-воздушных сил "Военно-воздушная академия имени профессора Н.Е. Жуковского и Ю.А. Гагарина" (г. Воронеж) Министерства обороны Российской Федерации | System of information transmitting |
-
1972
- 1972-11-23 DE DE19722257361 patent/DE2257361C1/de not_active Expired
-
1973
- 1973-09-03 GB GB4127473A patent/GB1448272A/en not_active Expired
- 1973-09-26 BE BE136059A patent/BE805334A/xx not_active IP Right Cessation
- 1973-10-15 NO NO3984/73A patent/NO137802C/en unknown
- 1973-11-08 IT IT31093/73A patent/IT1001671B/en active
- 1973-11-13 FR FR7340275A patent/FR2296974A1/en active Granted
- 1973-11-13 DK DK611773A patent/DK146989B/en unknown
- 1973-11-15 CA CA185,827A patent/CA1023486A/en not_active Expired
- 1973-11-21 NL NL7315914.A patent/NL156877B/en not_active IP Right Cessation
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2719545C1 (en) * | 2019-05-14 | 2020-04-21 | Федеральное государственное казенное военное образовательное учреждение высшего образования "Военный учебно-научный центр Военно-воздушных сил "Военно-воздушная академия имени профессора Н.Е. Жуковского и Ю.А. Гагарина" (г. Воронеж) Министерства обороны Российской Федерации | System of information transmitting |
Also Published As
Publication number | Publication date |
---|---|
DK611773A (en) | 1982-04-27 |
NL156877B (en) | 1978-05-16 |
FR2296974B1 (en) | 1979-03-09 |
DE2257361C1 (en) | 1976-07-22 |
NO137802B (en) | 1978-01-16 |
NO137802C (en) | 1978-04-26 |
DK146989B (en) | 1984-03-05 |
NL7315914A (en) | 1976-03-31 |
FR2296974A1 (en) | 1976-07-30 |
IT1001671B (en) | 1976-04-30 |
NO398473L (en) | 1976-01-12 |
BE805334A (en) | 1975-12-15 |
CA1023486A (en) | 1977-12-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4449246A (en) | Orderwire communication system | |
US4167700A (en) | Digital voice protection system and method | |
JPS62262530A (en) | Radio communication equipment | |
US4442518A (en) | Channel switching system for use in a digital communication system | |
US4258433A (en) | Digital data communication network having differing data transmission rate capabilities | |
KR890001476B1 (en) | Digital radio relay system | |
US2154921A (en) | Signaling system | |
GB1448272A (en) | Data transmission systems | |
GB952570A (en) | Data transmission apparatus | |
JPS6046861B2 (en) | Digital transmission relay method | |
US3944745A (en) | Secret signaling system with means for preventing key disclosure | |
US2471333A (en) | Phase reversal telegraph system | |
GB757612A (en) | Improvements in or relating to synchronising arrangements in electric telegraph systems | |
ES8602322A1 (en) | A method for cryptographic transmission of speech signals and a communication station for performing the method. | |
SU886277A2 (en) | Device for monitoring state of radio relay communication line stations | |
JPS58696B2 (en) | TDMA | |
AU593888B2 (en) | Apparatus for inserting locally derived analogue service signals into digital service channels in a radio relay station | |
US1480209A (en) | Carrier-wave call-signaling system | |
GB841412A (en) | Improvements in or relating to teleprinter systems | |
JP2944344B2 (en) | Call connection communication method | |
GB1502255A (en) | Network radio systems | |
JPH01140850A (en) | Line terminal equipment | |
GB1508971A (en) | Teleprinter systems | |
GB861249A (en) | Improvements in or relating to telegraph transmission systems | |
GB1187958A (en) | Improvements in or relating to Telecommunications Systems. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |