IPC 7 English version H04J !A-H04J 15/00

H04J-H04J01500

SECTION H – ELECTRICITY

H 04

ELECTRIC COMMUNICATION TECHNIQUE

H 04 J

MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L 5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N 7/08; in exchanges H04Q 11/00; stereophonic systems H04S)

Note

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.

Frequency-division multiplex systems (H04J 14/00 takes precedence) [5]

Details

Frequency-transposition arrangements

using digital techniques [3]

Arrangements for supplying the carrier waves

Arrangements for combining channels

Intermediate station arrangements, e.g. for branching, for tapping-off

Arrangements for reducing cross-talk between channels

Arrangements providing for calling or supervisory signals

Monitoring arrangements

in which all the carriers are amplitude-modulated (H04J 1/02 takes precedence) [3]

in which at least one carrier is angle-modulated (H04J 1/02 takes precedence) [3]

Time-division multiplex systems (H04J 14/00 takes precedence; relay systems H04B 7/14; selecting techniques H04Q) [4,5]

Details (electronic switching or gating H03K 17/00)

Distributors combined with modulators or demodulators

Synchronising arrangements

using pulse stuffing for systems with different or fluctuating information rates [3]

Intermediate station arrangements, e.g. for branching, for tapping-off

Arrangements for reducing cross-talk between channels

Arrangements providing for calling or supervisory signals

Monitoring arrangements

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) [4]

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]

using frequency compression and subsequent expansion of the individual signals

using resonant transfer [2]

in which the sources have different rates or codes [4]

in which the allocation is indicated by an address (H04J 3/17 takes precedence; in computers G06F 12/00, G06F 13/00) [4]

in which the information and the address are simultaneously transmitted [4]

Combined time-division and frequency-division multiplex systems (H04J 13/00 takes precedence) [2]

Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels

in which the polarity of the amplitude is characteristic

Multiplex systems in which each channel is represented by a different type of modulation of the carrier

11/

Orthogonal multiplex systems (H04J 13/00 takes precedence) [2]

13/

Code multiplex systems [2]

13/

using spread spectrum techniques [6]

13/

using direct sequence modulation [6]

13/

using frequency hopping [6]

14/

Optical multiplex systems (optical coupling, mixing or splitting, per se G02B) [5]

14/

Wavelength-division multiplex systems [5]

14/

Mode multiplex systems [5]

14/

Polarisation multiplex systems [5]

14/

Time-division multiplex systems [5]

15/

Multiplex systems not otherwise provided for [2]