GB1494671A - Pilot controlled data transmission systems - Google Patents
Pilot controlled data transmission systemsInfo
- Publication number
- GB1494671A GB1494671A GB708/75A GB70875A GB1494671A GB 1494671 A GB1494671 A GB 1494671A GB 708/75 A GB708/75 A GB 708/75A GB 70875 A GB70875 A GB 70875A GB 1494671 A GB1494671 A GB 1494671A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pilot
- band
- pilots
- detected
- faulty
- 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
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/46—Monitoring; Testing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
- H04B3/10—Control of transmission; Equalising by pilot signal
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
- Selective Calling Equipment (AREA)
- Radio Relay Systems (AREA)
Abstract
1494671 Transmission systems SIEMENS AG 8 Jan 1975 [18 Jan 1974] 708/75 Heading H4R Data exchanged between a first station Ul and a second station not shown is accompanied by a pilot whose frequency depends on the state of the transmission path in the opposite direction and which is detected to automatically raise the upper limit of a pilot band-stop filter when the pilot frequency exceeds a predetermined value. Pilots of 300, 315 or 330 Hz indicate that none or either of duplicate send and receive lines such as B1, B2 and Cl, C2 is faulty. The pilots are transmitted below the data band which starts at 360 Hz and are detected to change over a switch at the remote station to connect to the non-faulty line and return an appropriate pilot to U I to change over a similar switch 10. The filters such as 22 attenuate the pilots by 40 dB to prevent interference in monitoring the band below the data band. If both lines are faulty a pilot of 345 Hz is transmitted and this is detected to switch impedances in the filters to raise the cut-off to 360 Hz.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19742402451 DE2402451C2 (en) | 1974-01-18 | Message transmission device for transmitting a message transmission band, which is accompanied by a pilot with switchable frequency |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1494671A true GB1494671A (en) | 1977-12-07 |
Family
ID=5905140
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB708/75A Expired GB1494671A (en) | 1974-01-18 | 1975-01-08 | Pilot controlled data transmission systems |
Country Status (8)
Country | Link |
---|---|
JP (1) | JPS5330608B2 (en) |
BE (1) | BE824501A (en) |
FR (1) | FR2258749B1 (en) |
GB (1) | GB1494671A (en) |
IL (1) | IL46447A (en) |
IT (1) | IT1028339B (en) |
NL (1) | NL163927C (en) |
SE (1) | SE394782B (en) |
-
1975
- 1975-01-08 GB GB708/75A patent/GB1494671A/en not_active Expired
- 1975-01-14 IT IT19233/75A patent/IT1028339B/en active
- 1975-01-15 FR FR7501090A patent/FR2258749B1/fr not_active Expired
- 1975-01-15 SE SE7500405A patent/SE394782B/en unknown
- 1975-01-16 IL IL46447A patent/IL46447A/en unknown
- 1975-01-17 BE BE152473A patent/BE824501A/en not_active IP Right Cessation
- 1975-01-17 NL NL7500609.A patent/NL163927C/en not_active IP Right Cessation
- 1975-01-17 JP JP764975A patent/JPS5330608B2/ja not_active Expired
Also Published As
Publication number | Publication date |
---|---|
JPS5330608B2 (en) | 1978-08-28 |
BE824501A (en) | 1975-05-15 |
DE2402451A1 (en) | 1975-07-03 |
IT1028339B (en) | 1979-01-30 |
JPS50108807A (en) | 1975-08-27 |
NL163927B (en) | 1980-05-16 |
SE7500405L (en) | 1975-07-21 |
NL163927C (en) | 1980-10-15 |
IL46447A (en) | 1977-07-31 |
FR2258749A1 (en) | 1975-08-18 |
IL46447A0 (en) | 1975-04-25 |
NL7500609A (en) | 1975-07-22 |
DE2402451B1 (en) | 1975-07-03 |
SE394782B (en) | 1977-07-04 |
FR2258749B1 (en) | 1977-11-18 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |