Table of Contents
Advertisement
special signal called an "EOL" for distinguishing the delimiter of each
line. The start of the 1st line is also prefixed with an EOL. For this reason,
each coded line is enclosed by EOLs in each scanline in the horizontal
scanning direction. EOL is a bit pattern of 12 bits 000000000001
(expressed as 001 in Hex).
• RTC (Return To Control)
This special signal is appended onto the coded data of the final line to
show the end of a single page in the document. RTC comprises six consec-
utive EOLs.
• Data
This is the image data of one coded line. The data length of a line before it
is coded is determined by the size of the document, and all of the lines of
the document are the same length. However, as the data obtained by coding
those lines is uneven depending on the image of each line, the length of the
data is not fixed.
• Fill
This signal is for adjusting the time to be inserted to prevent the transmis-
sion time of a single line from being shorter than the minimum transmis-
sion time) described later when the time obtained by combining the data
and EOL is shorter than the minimum transmission time. Fills are a string
of 0 bits, and their length is not fixed. These signals are removed from the
image signal at reception.
3.2
Transmission Time
"Transmission time" is the time required to transmit image signals.
To determine the transmission time, the following three factors must be
considered:
These three factors are inter-related so the transmission time cannot be
determined by any single factor. Even if one is improved, it does not mean
that the transmission time will be shortened.
3.2.1 Transmission speed
The transmission speed of a MODEM is determined by the currently
adopted modulation system, and is expressed as bps (bits per second), in
other words, by how many bits that can be sent in a second. When the same
size of data is transmitted, the faster this transmission speed, the shorter
the transmission time becomes. Normally, multiple transmission speeds
• Transmission speed (determined by modulation system)
• Image data compression method (determined by coding scheme)
• Minimum transmission time (determined by product specifications)
G3 FACSIMILE COMMUNICATIONS
1
2
3
4
5
6
ït
çi
5–5
Advertisement
Table of Contents
