Class Notes

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use



Classification: 370/

A. This is the generic class for multiplexing or duplexing systems, methods, or apparatus.

(1) Note. Multiplexing includes for example, time division multiplexing (TDM) frequency division multiplexing (FDM), orthogonal and quasiorthogonal multiplexing techniques, phantom connections and plural channel adaptive systems.

(2) Note. Selective or telemetering systems which may be analogous to multiplexing techniques are not classified here but elsewhere. (See References to Other Classes, below.)

(3) Note. The distinction between multiplexing and selective or telemetry is: in multiplexing, the information is unrestricted as to content, e.g., a teletype-writer which uses an alphabet to transmit unlimited information, whereas in selective or telemetry devices, the information is restricted as to content, e.g., a transducer measuring a single parameter.

B. This class includes elements and circuits forming subcombinations having a utility unique to multiplexing such as rotary distributors used as multiplexers, synchronizers used to control distribution of multiplexed channels, bridge duplex circuits, resonant circuits having a special utility in a frequency division multiplexing system.

(1) Note. Multiplex modulators, per se, are not classified in this class. See classification elsewhere. (See References to Other Classes, below.)


A. Electrical circuits which may be used in multiplexing systems but are not unique to multiplex communications are classified in the appropriate class for such circuits. (See References to Other Classes, below.) B. Significantly claimed multiplex techniques in combination with the subject matter of Class 178, Telegraphy, Class 375, Pulse or Digital Communications, Class 379, Telephonic Communications, or Class 455 Telecommunications are classified in Class 370, Multiplex Communications.

C Significantly claimed apparatus external to this class, claimed in combination with apparatus under the class definition, which perform multiplexing operations, are classified in the class appropriate to the external device. (see paragraph B above). (See References to Other Classes, below for examples.)

D Nominally claimed apparatus external to this class in combination with apparatus under the class definition, is classified in this class unless provided for in the appropriate external class. For example, a nominally recited coupled network which includes significant multiplexing operations is classified herein.

E. Multiplexing systems and related devices found in other classes, for which see below



73, Measuring and Testing, appropriate subclass for significantly claimed apparatus external to this class (370) which perform multiplexing operations.

246, Railway Switches and Signals, appropriate subclass for multiplexed railway signalling information.

318, Electricity: Motive Power Systems,

562, for multiplexed data-transmission links utilized in a servo systems.

324, Electricity: Measuring and Testing, appropriate subclass for significantly claimed apparatus external to this class (370) which perform multiplexing operations. 327, Electrical Transmission or Interconnection Systems,

407+, and 415+ for converging and diverging signal switched paths, respectively.

329, Demodulators,

300+, for frequency shift keying demodulator; subclasses 304+ for phase shift keying demodulator; subclasses 311+ for pulse demodulator; subclasses 315+ for frequency modulation demodulator; subclasses 345+ for phase modulation demodulator; and subclasses 347+ for amplitude modulation demodulator.

332, Modulators,

100+, for frequency shift keying modulator; subclasses 103+ for phase shift keying modulator; subclasses 117+ for frequency modulator; and subclasses 149+ for amplitude modulator.

332, Modulators,

106+, for multiplex pulse modulation, subclasses 119+ for multiplex frequency modulation, subclasses 144+ for multiplex phase modulation, and subclasses 151+ for multiplex amplitude modulation.

333, Wave Transmission Lines and Networks,

1, for plural transmission lines or networks; subclass 4 for balanced transmission lines; subclass 117 for hybrid-type networks; and subclasses 165 through 167 for wave filters.

340, Communications: Electrical, 853.1+, for geophysical systems which may include multiplexing means; subclasses 825+ for selective systems analogous to multiplexing systems; subclasses 870.11+ for telemetering which may include multiplexing means.

341, Coded Data Generation or Conversion,

141, for multiplex in analog to or from digital conversion.

342, Communications: Directive Radio Wave System and Devices (e.g., Radar, Radio Navigation),

1, 25 for radar systems which may include multiplexing systems.

345, Computer Graphics Processing, Operator Interface Processing, and Selective Visual Display Systems, appropriate subclasses for display communications which may include multiplexing means.

348, Television, appropriate subclasses for television signal transmission which may use multiplexing techniques.

358, Facsimile,

425, for multiplex facsimile information.

359, Optics: Systems (Including Communication) and Elements,

113+, for duplex optical communication and subclasses 115+ for multiplex optical communication.

360, Dynamic Magnetic Information Storage or Retrieval, 18+, for multiplex magnetic information.

365, Static Information Storage and Retrieval,

189.01+, and 230.01+, for a static memory system with the handling of signal information or the addressing of memory locations respectively analogous to multiplexing techniques particularly subclasses 189.02 and 230.02 for such a system having multiplexed signals in each of the respective systems.

369, Dynamic Information Storage or Retrieval,

102, for plural information signals multiplexed on an optical storage track..

381, Electrical Audio Signal Processing Systems and Devices,

1+, for stereo, especially subclasses 2+ for broadcast and

multiplex stereo.

385, Optical Waveguides,

1+, 4+, or 16+ for optical waveguides with modulation or switching.

702, Data Processing: Measuring, Calibrating, or Testing, Class appropriate subclasses for significantly claimed apparatus external to this class (370) which perform multiplexing operations.

709, Electrical Computers and Digital Processing Systems: Multiple Computer or Process Coordinating, 200.3+, for general purpose programmable computers which may include multiplexing techniques wherein data is transferred between the computers and processing of the data by the computers occurs before or after the data transfer operation.

710, Electrical Computers and Digital Data Processing Systems: Input/Output,

131+, for data processing intrasystem connection which may use a bus switch.

714, Error Detection/Correction and Fault Detection/Recovery,

3+, for replacement with spare devices, subclass 4 for reconfiguring transmission facility, and subclasses 712+ for transmission facility testing.



The simultaneous transmission of two or more information signals in either or both directions over a common (same) transmission medium in such a manner that the information signals may be discretely recovered.