1. A form of
telegraphy for the
transmission of fixed images, with or without half-tones, with a view to their reproduction in a permanent form. In this definition the term telegraphy has the same general meaning as defined in the Convention. [
NTIA ] [
RR ]
2. The process by which fixed graphic images, such as printed text and pictures, are scanned, and the
information converted into electrical signals that may be transmitted over a telecommunications
system and used to create a
copy of the original, or an image so produced. (
188 )
Note 1: Wirephoto and
telephoto are facsimile via wire circuits. Radiophoto is facsimile via
radio .
Note 2: Technology now exists that permits the transmission and reception of facsimile
data to or from a
computer without requiring
hard copy at either end.
Note 3: Current facsimile systems are designated and defined as follows:
Group 1 Facsimile: The mode of black and white facsimile
operation , defined in
CCITT Recommendation T.2, that uses double
sideband modulation without any special measures to compress the
bandwidth . Note 1: A 216 × 279-mm document, i.e. , an 8½ × 11-inch document, may be transmitted in approximately 6 minutes via a
telephone -type
circuit . Additional modes in this group may be designed to operate at a lower
resolution suitable for the
transmission of 216 × 279-mm documents in 3 to 6 minutes. Note 2: The CCITT frequencies used are 1300 Hz for white and 2300 Hz for black. The North American
standard is 1500 Hz for white and either 2300 or 2400 Hz for black.
Group 2 Facsimile: The mode of black and white facsimile
operation , defined in
CCITT Recommendation T.3, that accomplishes
bandwidth compression by using encoding and vestigial
sideband , but excludes processing of the document
signal to reduce
redundancy . Note: A 216 × 279-mm document, i.e. , an 8½ × 11-inch document, may be transmitted in approximately 3 minutes using a 2100-Hz AM/PM/VSB, over a
telephone -type
circuit .
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