Classifications

• • 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
• • 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
  • H04M1/677—Preventing the dialling or sending of predetermined telephone numbers or selected types of telephone numbers, e.g. long distance numbers

Landscapes

• Engineering & Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Transmission Devices (AREA)
• Mobile Radio Communication Systems (AREA)
• Telephone Set Structure (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4516927

Family Applications (1)

Country Status (7)

Families Citing this family (2)

• 0
  • BE BE423200D patent/BE423200A/xx unknown
  • NL NL48597D patent/NL48597C/xx active
• 1936
  • 1936-08-19 CH CH195491D patent/CH195491A/fr unknown
• 1937
  • 1937-08-18 US US159790A patent/US2216850A/en not_active Expired - Lifetime
  • 1937-08-19 FR FR825777D patent/FR825777A/fr not_active Expired
  • 1937-08-19 GB GB22774/37A patent/GB500971A/en not_active Expired
  • 1937-08-20 DE DE1937M0138992 patent/DE690679C/de not_active Expired

Also Published As

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