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DIFF Subgroup
H04L 27/26

Systems using multi-frequency codes (H04L27/32 takes precedence)

Introduced: September 1968

Title

Titles differ between systems:

IPC: Systems using multi-frequency codes

CPC: Systems using multi-frequency codes (H04L27/32 takes precedence)

Full Title

Full titles differ between systems:

IPC:

Modulated-carrier systems > Systems using multi-frequency codes

CPC:

Modulated-carrier systems > Systems using multi-frequency codes (H04L27/32 takes precedence)

Of 3 combined children, 2 exist in both systems.

1 codes are CPC-only extensions.

Child Classifications

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  • H04L 27/28 with simultaneous transmission of different frequencies each representing one code element IPC+CPC Available in IPC and CPC
  • H04L 27/30 wherein each code element is represented by a combination of frequencies IPC+CPC Available in IPC and CPC