3878322

Information

• Patent Grant
• 3878322

• References
• Source

• Patent Number

  3,878,322

• Date Filed

  Not available

• Date Issued

  Tuesday, April 15, 1975
  49 years ago

• CPC

  • H04Q9/12 - using combinations of frequencies
  • G08B26/00 - Alarm systems in which substations are interrogated in succession by a central station
  • G08B26/003 - replying the identity and the state of the sensor
  • H04H60/21 - Billing for the use of broadcast information or broadcast-related information
  • H04H60/32 - Arrangements for monitoring conditions of receiving stations
  • H04H60/43 - for identifying broadcast channels
  • H04H60/96 - CATV systems
  • H04N7/17309 - Transmission or handling of upstream communications
  • H04N2007/17372 - the upstream transmission being initiated or timed by a signal from upstream of the user terminal

• US Classifications

  • 725 - Interactive video distribution systems
  • 340 - Communications: electrical
  • 348 - Television