H
SECTION H — ELECTRICITY
 H04
ELECTRIC COMMUNICATION TECHNIQUE
 H04

Note(s)

This class covers electrical communication systems with propagation paths employing light (optical communication), infra-red, ultrasonic, sonic, or infrasonic waves.

 H04J
MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L 5/00; systems for transmitting television signals simultaneously or sequentially H04N 7/08; in exchanges H04Q 11/00; stereophonic systems H04S)
 H04J

Note(s)

This subclass covers:

  • circuits or apparatus for combining or dividing signals for the purpose of transmitting them simultaneously or sequentially over the same transmission path;
  • monitoring arrangements therefor.

 H04J 1/00
Frequency-division multiplex systems
 H04J 1/02
·  Details
 H04J 1/04
·  ·  Frequency-transposition arrangements
 H04J 1/05
·  ·  ·  using digital techniques  [3]
 H04J 1/06
·  ·  Arrangements for supplying the carrier waves
 H04J 1/08
·  ·  Arrangements for combining channels
 H04J 1/10
·  ·  Intermediate station arrangements, e.g. for branching, for tapping-off
 H04J 1/12
·  ·  Arrangements for reducing cross-talk between channels
 H04J 1/14
·  ·  Arrangements providing for calling or supervisory signals
 H04J 1/16
·  ·  Monitoring arrangements
 H04J 1/18
·  in which all the carriers are amplitude-modulated (H04J 1/02 takes precedence)  [3]
 H04J 1/20
·  in which at least one carrier is angle-modulated (H04J 1/02 takes precedence)  [3]
 H04J 3/00
Time-division multiplex systems (relay systems H04B 7/14; selecting techniques H04Q)
 H04J 3/02
·  Details (electronic switching or gating H03K 17/00)
 H04J 3/04
·  ·  Distributors combined with modulators or demodulators
 H04J 3/06
·  ·  Synchronising arrangements
 H04J 3/07
·  ·  ·  using pulse stuffing for systems with different or fluctuating information rates  [3]
 H04J 3/08
·  ·  Intermediate station arrangements, e.g. for branching, for tapping-off
 H04J 3/10
·  ·  Arrangements for reducing cross-talk between channels
 H04J 3/12
·  ·  Arrangements providing for calling or supervisory signals
 H04J 3/14
·  ·  Monitoring arrangements
 H04J 3/16
·  in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted (H04J 3/17, H04J 3/24 take precedence)
 H04J 3/17
·  in which the transmission channel allotted to a first user may be taken away and re-allotted to a second user if the first user becomes inactive, e.g. TASI  [4]
 H04J 3/18
·  using frequency compression and subsequent expansion of the individual signals
 H04J 3/20
·  using resonant transfer  [2]
 H04J 3/22
·  in which the sources have different rates or codes  [4]
 H04J 3/24
·  in which the allocation is indicated by an address (H04J 3/17 takes precedence; in computers G06F 12/00, G06F 13/00)  [4]
 H04J 3/26
·  ·  in which the information and the address are simultaneously transmitted  [4]
 H04J 4/00
Combined time-division and frequency-division multiplex systems (H04J 13/00 takes precedence)  [2]
 H04J 6/00
( transferred to H04J 3/17, H04J 3/24 )
 H04J 6/02
( transferred to H04J 3/17 )
 H04J 7/00
Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels
 H04J 7/02
·  in which the polarity of the amplitude is characteristic
 H04J 9/00
Multiplex systems in which each channel is represented by a different type of modulation of the carrier
 H04J 11/00
Orthogonal multiplex systems (H04J 13/00 takes precedence)  [2]
 H04J 13/00
Code multiplex systems  [2]
 H04J 15/00
Multiplex systems not otherwise provided for  [2]