H04 ELECTRIC COMMUNICATION TECHNIQUE
Description
H04 – ELECTRIC COMMUNICATION TECHNIQUE This class encompasses the technical and engineering aspects of electrical communication systems, including signal transmission, reception, and processing across various media and frequencies. It covers wire-based communication (telephony, telegraphy, data transmission), wireless communication (radio, microwave, satellite), optical communication, and associated infrastructure such as switching, routing, and network control systems. The class includes technologies for analog and digital signal modulation, coding, multiplexing, and error detection/correction, as well as the hardware and methods for establishing and maintaining communication links. Adjacent classes within the broader electrical field provide related coverage of power distribution (H02), lighting (H05B), and specific electronic components used in communication systems.
Of 12 combined children, 11 exist in both systems.
1 codes are CPC-only extensions.
7 shared codes have differing titles between IPC and CPC.
Child Classifications
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- H04H BROADCAST COMMUNICATION (multiplex communication H04J; pictorial communication aspects of broadcast systems H04N) heading +1 CPC IPC+CPC Available in IPC and CPC
- H04J MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) heading +2 CPC IPC+CPC Available in IPC and CPC
- H04L TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) heading +7 CPC −1 IPC IPC+CPC Available in IPC and CPC
- H04M TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) heading +6 CPC IPC+CPC Available in IPC and CPC
- H04N PICTORIAL COMMUNICATION, e.g. TELEVISION heading +4 CPC −1 IPC IPC+CPC Available in IPC and CPC
- H04Q SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) heading +3 CPC IPC+CPC Available in IPC and CPC
- H04R LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) heading +17 CPC IPC+CPC Available in IPC and CPC
- H04T INDEXING SCHEME ASSOCIATED WITH CLASS H04, RELATING TO STANDARDS FOR ELECTRIC COMMUNICATION TECHNIQUE heading +3 CPC CPC only CPC only
- H04W WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) heading since 2009 IPC+CPC Available in IPC and CPC