GB2205216B - Circuit arrangement for monitoring a telephone line - Google Patents
Circuit arrangement for monitoring a telephone lineInfo
- Publication number
- GB2205216B GB2205216B GB8810646A GB8810646A GB2205216B GB 2205216 B GB2205216 B GB 2205216B GB 8810646 A GB8810646 A GB 8810646A GB 8810646 A GB8810646 A GB 8810646A GB 2205216 B GB2205216 B GB 2205216B
- Authority
- GB
- United Kingdom
- Prior art keywords
- monitoring
- telephone line
- circuit arrangement
- telephone
- arrangement
- 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 - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/68—Circuit arrangements for preventing eavesdropping
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/66—Substation equipment, e.g. for use by subscribers with means for preventing unauthorised or fraudulent calling
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M17/00—Prepayment of wireline communication systems, wireless communication systems or telephone systems
- H04M17/02—Coin-freed or check-freed systems, e.g. mobile- or card-operated phones, public telephones or booths
- H04M17/023—Circuit arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Telephonic Communication Services (AREA)
- Monitoring And Testing Of Exchanges (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19873715580 DE3715580A1 (en) | 1987-05-09 | 1987-05-09 | CIRCUIT ARRANGEMENT FOR MONITORING A TELEPHONE CONNECTION LINE |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8810646D0 GB8810646D0 (en) | 1988-06-08 |
GB2205216A GB2205216A (en) | 1988-11-30 |
GB2205216B true GB2205216B (en) | 1991-01-23 |
Family
ID=6327224
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8810646A Expired - Lifetime GB2205216B (en) | 1987-05-09 | 1988-05-05 | Circuit arrangement for monitoring a telephone line |
Country Status (3)
Country | Link |
---|---|
CH (1) | CH674784A5 (en) |
DE (1) | DE3715580A1 (en) |
GB (1) | GB2205216B (en) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4989239A (en) * | 1989-09-15 | 1991-01-29 | Mars Incorporated | Method and apparatus for preventing pay telephone fraud and reducing handset vandalism |
EP0454262A1 (en) * | 1990-04-26 | 1991-10-30 | Koninklijke KPN N.V. | Electronic circuit for signalling and/or preventing improper use of a telephone subscriber line |
EP0474172A3 (en) * | 1990-09-06 | 1993-03-03 | Teletron Ltd. | Telephone line monitoring apparatus and method |
FR2672757B1 (en) * | 1991-02-08 | 1999-02-26 | France Telecom | DEVICE FOR DETECTING AN UNAUTHORIZED CONNECTION ON A SUBSCRIBER TELEPHONE LINE. |
FR2674397A1 (en) * | 1991-03-20 | 1992-09-25 | Regnier Marc | Device for monitoring a subscriber line allowing detection and recording of electrical signals related to an illicit tapping |
SG44843A1 (en) * | 1992-10-14 | 1997-12-19 | Philips Electronics Nv | Device for detecting the activation of a parallel connected telephone set |
JPH0795284A (en) * | 1993-09-20 | 1995-04-07 | Fujitsu Ltd | Communications terminal provided with function for detecting and preventing lie branching |
DK11995A (en) * | 1994-05-02 | 1995-11-03 | Christian Henri Krause | Telephone system fuse |
DE4421615C1 (en) * | 1994-06-21 | 1996-12-05 | Matthias Dipl Ing Viehmann | Circuit arrangement for external interference protection for the wired telephone network |
DE19650007A1 (en) * | 1996-11-23 | 1998-06-04 | Ekkehard Dr Ing Dreetz | Telecommunication path protection method |
GB2330270B (en) * | 1997-10-09 | 2002-08-07 | Inventec Corp | Pay phone security protection circuit |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1278530B (en) * | 1965-07-28 | 1968-09-26 | Siemens Ag | Circuit arrangement for telecommunication switching systems, in particular of telephone extension systems with test circuits |
-
1987
- 1987-05-09 DE DE19873715580 patent/DE3715580A1/en active Granted
-
1988
- 1988-05-03 CH CH165388A patent/CH674784A5/de not_active IP Right Cessation
- 1988-05-05 GB GB8810646A patent/GB2205216B/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
DE3715580A1 (en) | 1988-11-24 |
CH674784A5 (en) | 1990-07-13 |
GB2205216A (en) | 1988-11-30 |
DE3715580C2 (en) | 1992-02-06 |
GB8810646D0 (en) | 1988-06-08 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19940505 |