Communication terminal apparatus and communication method for communicating data through a plurality of communication channels

When there are unused communication channels, it is checked whether an attribute of an image associated with transmission image data indicates color image data or monochrome image data. If the transmission image data is monochrome image data, the image data is transmitted through one of B channels of a line. If the transmission image data is color image data, and two B channels can be used, bulk transmission is performed by simultaneously using the two B channels. If it is determined that the two B channels cannot be simultaneously used, the image data is transmitted by using one of the B channels which is in a unused state.

BACKGROUND OF THE INVENTION 
The present invention relates to a communication terminal apparatus for 
performing communication upon determining the number of communication 
channels in accordance with transmission data, and a communication method 
therefor. 
In a conventional communication terminal apparatus, communication is always 
performed with a maximum number of channels through which the apparatus 
can perform communication, regardless of the type of data to be 
communicated. 
In the conventional communication terminal apparatus described above, since 
communication is always performed with the maximum number of channels 
regardless of the amount of data, communication cannot be performed with a 
communication channel count corresponding to the optimal cost for line 
usage or optimal communication time for the amount of transmission data. 
SUMMARY OF THE INVENTION 
The present invention has been made in consideration of the above 
situation, and has as its object to provide a communication terminal 
apparatus which can perform communication with an optimal number of 
channels for transmission data. 
In order to achieve the above object, according to the present invention, 
there is provided a communication terminal apparatus, accommodating a line 
having a plurality of communication channels, for transmitting/receiving 
data through the plurality of communication channels, comprising means for 
detecting unused states of the plurality of communication channels, 
judging means for judging a data attribute associated with the amount of 
transmission data, and determining means for determining the number of 
channels, of the communication channels, used for transmission of the 
transmission data on the basis of the unused states and the data 
attribute. 
In addition, according to the present invention, there is provided a 
communication terminal apparatus, accommodating a line having a plurality 
of communication channels, for transmitting/receiving data through the 
plurality of communication channels, comprising means for calculating a 
communication time on the basis of the amount of transmission data and the 
number of channels of the communication channels, means for calculating a 
usage for the line on the basis of charge information associated with the 
communication time and the line, and means for visually displaying the 
communication time and the usage, wherein an operator of the communication 
terminal apparatus selects the number of channels for transmitting the 
transmission data on the basis of visually displayed contents. 
Other features and advantages of the present invention will be apparent 
from the following description taken in conjunction with the accompanying 
drawings, in which like reference characters designate the same or similar 
parts throughout the figures thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The preferred embodiments of the present invention will be described in 
detail below with reference to the accompanying drawings. 
First Embodiment! 
FIG. 1 is a block diagram showing the overall arrangement of a 
color/monochrome facsimile apparatus (to be referred to as an apparatus 
hereinafter) according to the first embodiment of the present invention, 
which is connected to an integrated services digital network (ISDN) for 
providing two B channels at 64 kbits/s and one D channel at 16 kbits/s 
(commonly called 2B+D) as a user/network interface. Referring to FIG. 1, 
reference numeral 1 denotes a character generator (CG) circuit for 
generating characters to be printed on a report output from the apparatus; 
2, a CPU control circuit having a ROM 2a and a RAM 2b and controlling the 
overall apparatus; and 13, a direct memory access (DMA) control circuit 
for performing inter-memory transfer of image data without the mediacy of 
the CPU control circuit 2. 
Reference numeral 4 denotes a color/monochrome conversion circuit for 
converting C, M, Y, and K (cyan, magenta, yellow, and black) images into 
R, G, and B (red, green, and blue) images. The color/monochrome conversion 
circuit 4 has a .gamma. conversion circuit 3 for converting R, G, and B 
images into C, M, Y, and K images and also performs conversion from a 
color image into a monochrome image or from a multivalued image into a 
binary image. Reference numeral 5 denotes a pixel density conversion 
circuit for converting a density of image data and reference numeral 6 
denote a frame memory for developing image data in units of blocks. 
Reference numeral 7 denotes a communication control section for performing 
outgoing/incoming call control and image data transmission/reception 
control with respect to a distant station terminal apparatus through a 
communication line 20, accommodated from the ISDN, by using a 
predetermined communication protocol; and 8, an I/O control section for 
controlling a key input unit 9, a display unit 10, a scanner unit 11, and 
a printer unit 12. The key input unit 9 serves to receive an instruction 
input by a key input operation by a user, such as a key input instruction 
input by operating a start button or a stop button, a copy count 
designation, and a page number designation, and the like. The display unit 
10 displays a message on an LCD (not shown) and notifies the user of 
various information, e.g., a shortage of paper, a memory full state, and a 
shortage of ink, and various messages by turning on/off LDEs. The scanner 
unit 11 reads a document in accordance with designated modes, e.g., a 
paper size mode, a color/monochrome mode, and a density mode. The printer 
unit 12 serves to output image data and character data onto a recording 
sheet. 
An image coding/decoding circuit 14 compresses/expands color and monochrome 
image data. A small computer system interface (SCSI) 15 provides the 
interface with a hard disk (HD) unit 16 as a nonvolatile memory. Reference 
numeral 17 denotes an image bus serving as a transmission path for image 
data; and 18, a system bus associated with the overall control of the 
apparatus. 
The operation of the apparatus of the embodiment, especially determination 
of the number of channels used for data communication, will be described 
next. &lt;Determination of the number of channels in accordance with the type 
of data&gt; 
FIG. 2 is a flow chart showing the procedure for determining the number of 
channels, in the apparatus according to the embodiment, depending on 
whether transmission image data is color image data or monochrome image 
data. 
When the apparatus is set in the transmission mode, it is checked in step 
S11 whether any unused communication channels are present. If NO in step 
S11, the flow advances to step S16 to set the apparatus in a transmission 
standby state, thus terminating the operation. 
If YES in step S11, the flow advances to step S12 to check an attribute of 
an image associated with the transmission image data, i.e., check whether 
the transmission image data is color image data (or data including color 
image data) or monochrome image data. If it is determined in step S12 that 
the transmission image data is monochrome image data, the flow advances to 
step S15 to transmit the image data by using one B channel, thus 
terminating the operation. 
If it is determined in step S12 that the transmission image data is color 
image data, it is checked in step S13 whether the two B channels can be 
used. If NO in step S13, the flow advances to step S15 to transmit the 
image data by using one B channel. Thereafter, the operation is 
terminated. 
If YES in step S13, i.e., if it is determined that the two B channels can 
be used, the flow advances to step S14 to transmit the image data by 
simultaneously using the two B channels, i.e., transmit the image data by 
a bulk transmission scheme. Thereafter, the operation is terminated. 
&lt;Determination of the number of channels in accordance with resolution&gt; 
FIG. 3 is a flow chart showing the procedure for determining the number of 
channels, in the apparatus of the embodiment, depending on whether the 
resolution of transmission image data is 400 dpi. 
When the apparatus of the embodiment is set in the transmission mode, it is 
checked in step S21 whether any unused communication channels are present. 
If NO in step S21, the flow advances to step S26 to set the apparatus in a 
transmission standby state, thus terminating the operation. If YES in step 
S21, the flow advances to step S22 to check whether the resolution of the 
transmission image data is 400 dpi (or more), or lower than 400 dpi. If it 
is determined in step S22 that the resolution of the transmission image 
data is lower than 400 dpi, the flow advances to step S25 to transmit the 
image data by using one B channel, thus terminating the operation. 
If it is determined in step S22 that the resolution of the transmission 
image data is 400 dpi, it is checked in step S23 whether the two B 
channels can be used. If NO in step S23, the flow advances to step S25 to 
transmit the image data by using one B channel. Thereafter, the operation 
is terminated. 
If YES in step S23, i.e., if it is determined that the two B channels can 
be used, the flow advances to step S24 to transmit the image data by 
simultaneously using the two B channels, i.e., transmit the image data by 
the bulk transmission scheme. Thereafter, the operation is terminated. 
&lt;Determination of the number of channels in accordance with the size of 
data&gt; 
FIG. 4 is a flow chart showing the procedure for determining the number of 
channels depending on whether the size of transmission image data is A3 or 
B4, or A4 or B5. 
When the apparatus of the embodiment is set in the transmission mode, it is 
checked in step S31 whether any unused communication channels are present. 
If NO in step S31, the flow advances to step S36 to set the apparatus in a 
transmission standby state, thus terminating the operation. 
If YES in step S31, the flow advances to step S32 to check whether the size 
of the transmission data is A3 or B4, or A4 or B5. If it is determined 
that the size of the transmission image data is A4 or B5, the flow 
advances to step S35 to transmit the image data by using one B channel, 
thus terminating the operation. 
If it is determined in step S32 that the size of the transmission image 
data is A3 or B4, it is checked in step S33 whether the two B channels can 
be used. If NO in step S33, the flow advances to step S35 to transmit the 
image data by using one B channel. Thereafter, the operation is 
terminated. 
If YES in step S33, the flow advances to step S34 to transmit the image 
data by simultaneously using the two B channels, i.e., transmit the image 
data by the bulk transmission scheme. Thereafter, the operation is 
terminated. &lt;Determination of the number of channels in accordance with 
the number of pages of transmission image data&gt; 
FIG. 5 is a flow chart showing the procedure for determining the number of 
channels depending on whether the number of pages of transmission image 
data exceeds a specified number of pages. 
In step S41 in FIG. 5, a transmission data page count is compared with a 
page count boundary value stored in the ROM 2a in the CPU control circuit 
2 in advance. If it is determined in step S42 that the transmission data 
page count is larger than the page count boundary value, the flow advances 
to step S43 to transmit the transmission data by simultaneously using the 
two B channels. 
If it is determined in step S42 that the transmission data page count is 
smaller than the page count boundary value, the flow advances to step S44 
to transmit the image data by using one B channel, thus terminating the 
operation. 
In this manner, as the number of pages of transmission data increases, a 
larger number of communication channels are used, and vice versa. 
As described above, the number of communication channels is determined in 
accordance with the attributes of an image associated with transmission 
image data. For example, a larger number of communication channels are 
used when color image data is transmitted than when monochrome image data 
is transmitted, thereby saving the cost for line usage and realizing 
effective use of the line. 
In the above-described embodiment, in determining the number of channels in 
accordance with the resolution of transmission data, when the resolution 
is lower than 400 dpi, one B channel is used. However, the present 
invention is not limited to the embodiment described above. For example, 
when the resolution is lower than 300 dpi, one B channel may be used. 
It is apparent that an image size as a criterion is not limited to the 
above-mentioned size. In addition, a color/monochrome facsimile apparatus 
is used as a facsimile apparatus in the above-described embodiment. 
However, the present invention can be applied to a monochrome facsimile 
apparatus. 
In the above-described case where the number of channels is determined in 
accordance with the number of pages of transmission image data, the number 
of page count boundary values is not limited to one. For example, two page 
count boundary values may be set for color image data transmission and 
monochrome image data transmission, respectively. In addition, as in the 
case where 23B+D channels are supplied as interfaces for an ISDN, if three 
or more communication channels are available, a plurality of page count 
boundary values may be prepared in a stepwise manner. 
Second Embodiment! 
The second embodiment of the present invention will be described below. 
Since the arrangement of a facsimile apparatus according to the second 
embodiment is the same as that of the facsimile apparatus according to the 
first embodiment, its illustration and description will be omitted. 
FIG. 6 is a flow chart showing the operation of the apparatus of this 
embodiment in the transmission mode. In step S51 in FIG. 6, a CPU control 
circuit 2 of the apparatus calculates the cost for line usage and 
communication time corresponding to the number of channels used on the 
basis of the amount of transmission data and the transmission rate of a 
communication line. For example, a communication time in the use of n 
channels is calculated as follows: 
##EQU1## 
In step S52, for example, a communication time per 10 yen is obtained by 
referring to the communication time table shown in FIG. 7, which is stored 
in the ROM 2a of the CPU control circuit 2 in advance, on the basis of the 
communication time calculated in step S51, the area code of a data 
transmission destination, input by the operator, and the subscriber's 
telephone number of the apparatus. Thereafter, the cost for line usage per 
channel is calculated by the following equation, based upon the 
communication time obtained above. 
##EQU2## 
It is apparent that when n channels are used, the cost for line usage 
obtained by equation (2) is multiplied by n. 
In step S53, the cost for line usage and the communication time calculated 
in steps S51 and S52 are displayed on the LCD of the display unit 10. In 
step S54, the operator is caused to select the number of communication 
channels through the key input unit 9. In step S55, a line corresponding 
to the number of communication channels selected in step S54 is connected. 
In step S56, data is transmitted by using the line connected in step S55. 
Upon completion of the data transmission, the line is disconnected in step 
S57, thus terminating the operation. 
In this manner, the cost for line usage and a communication time are 
calculated and displayed, and the operator is caused to select the number 
of communication channels on the basis of the calculated data, thereby 
allowing communication with a desired cost for line usage and a desired 
communication time. With this operation, a reduction in the cost for line 
usage and effective use of the line can be realized. 
In the above-described embodiment, determination of the number of 
communication channels and connection of a line may be performed in an 
arbitrary order. In addition, as a facsimile apparatus, either a 
color/monochrome facsimile apparatus or a monochrome facsimile apparatus 
may be used. 
Note that the present invention may be applied to both a system constituted 
by a plurality of units and an apparatus constituted by a single unit. In 
addition, as is apparent, the present invention can be applied to a case 
where the above-described operation can be realized by supplying programs 
to a system or an apparatus. 
As many apparently widely different embodiments of the present invention 
can be made without departing from the spirit and scope thereof, it is to 
be understood that the invention is not limited to the specific 
embodiments thereof except as defined in the appended claims.