GB2037540A - Monitoring device for monitoring telephone calls coming through a subscriber station - Google Patents

Monitoring device for monitoring telephone calls coming through a subscriber station

Info

Publication number
GB2037540A
GB2037540A GB8003187A GB8003187A GB2037540A GB 2037540 A GB2037540 A GB 2037540A GB 8003187 A GB8003187 A GB 8003187A GB 8003187 A GB8003187 A GB 8003187A GB 2037540 A GB2037540 A GB 2037540A
Authority
GB
United Kingdom
Prior art keywords
monitoring
subscriber station
telephone calls
station
calls coming
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.)
Granted
Application number
GB8003187A
Other versions
GB2037540B (en
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.)
DE TOLEDO P
Original Assignee
DE TOLEDO P
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 DE TOLEDO P filed Critical DE TOLEDO P
Publication of GB2037540A publication Critical patent/GB2037540A/en
Application granted granted Critical
Publication of GB2037540B publication Critical patent/GB2037540B/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • H04M1/663—Preventing unauthorised calls to a telephone set
    • H04M1/665—Preventing unauthorised calls to a telephone set by checking the validity of a code

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Signal Processing (AREA)
  • Interface Circuits In Exchanges (AREA)
  • Telephonic Communication Services (AREA)
  • Monitoring And Testing Of Exchanges (AREA)
  • Alarm Systems (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Devices For Supply Of Signal Current (AREA)

Abstract

The object of the device is to monitor telephone calls coming through a subscriber station before they are transmitted to this station. It comprises switching means (RL1, RL2, RL3) aimed at being connected to the subscriber line, reception and detection means (RF1, RF3, RF5) of a coded sound frequency signal transmitted by the subscriber line and control means for controlling the switching means, associated to the detection means altogether assembled so as to connect the subcriber line to the station after reception and detection of the coded signals. The device is aimed at being connected on any subscriber station.
GB8003187A 1978-05-30 1979-05-25 Monitoring device for monitoring telephone calls coming through a subscriber station Expired GB2037540B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH587878A CH623695A5 (en) 1978-05-30 1978-05-30

Publications (2)

Publication Number Publication Date
GB2037540A true GB2037540A (en) 1980-07-09
GB2037540B GB2037540B (en) 1982-08-18

Family

ID=4300837

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8003187A Expired GB2037540B (en) 1978-05-30 1979-05-25 Monitoring device for monitoring telephone calls coming through a subscriber station

Country Status (5)

Country Link
CH (1) CH623695A5 (en)
FR (1) FR2427748A1 (en)
GB (1) GB2037540B (en)
SE (1) SE420555B (en)
WO (1) WO1979001145A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2203614A (en) * 1987-04-09 1988-10-19 British Broadcasting Corp Control of access to a telephone
GB2240903A (en) * 1990-02-13 1991-08-14 Proton Communications Automatic telephone call interceptor and interrogator devices

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4439638A (en) * 1982-01-28 1984-03-27 International Mobile Machines Corp. Sound-activated code-controlled detection system for telephones and the like

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3829616A (en) * 1974-06-28 1974-08-13 Int Mobile Machines Ringer blocking attachment for telephones

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2203614A (en) * 1987-04-09 1988-10-19 British Broadcasting Corp Control of access to a telephone
GB2240903A (en) * 1990-02-13 1991-08-14 Proton Communications Automatic telephone call interceptor and interrogator devices
GB2240903B (en) * 1990-02-13 1994-07-13 Proton Communications Automatic telephone call interceptor and interrogator devices

Also Published As

Publication number Publication date
SE8000586L (en) 1980-01-25
SE420555B (en) 1981-10-12
FR2427748B1 (en) 1982-06-11
CH623695A5 (en) 1981-06-15
GB2037540B (en) 1982-08-18
WO1979001145A1 (en) 1979-12-27
FR2427748A1 (en) 1979-12-28

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee