Telephonic communications – Telephone line or system combined with diverse electrical... – To produce visual-graphic copy
Reexamination Certificate
2002-07-22
2003-08-12
Eng, George (Department: 2643)
Telephonic communications
Telephone line or system combined with diverse electrical...
To produce visual-graphic copy
C379S093320, C358S436000
Reexamination Certificate
active
06606375
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a data communication apparatus and a data communication method, which shortens the time needed for a previous-procedure to be performed prior to data communication using a modem, such as facsimile communication.
BACKGROUND ART
Recently, in data communication apparatus, data communication using a V.34 modem (33.6 kbps), which is conformed to recommends of the ITU-T. The ITU-T also recommends T30 ANEXF (so-called Super G3) as facsimile communication standards using the V.34 modem for facsimile apparatuses. A previous-procedure for facsimile communication is carried out according to the standards procedure, after which communication of image data is executed.
Such a communication protocol will be explained based on the sequence chart illustrated in FIG.
1
.
FIG. 1
is a control signal view for a communication protocol for facsimile communication according to prior art.
Referring to
FIG. 1
, reference character
19
a
denotes a communication procedure for selecting a modulation mode from among a V34 half-duplex, V34 full duplex, V17 half-duplex, etc. Reference character
19
b
denotes a communication procedure for line probing to check a line and determine various kinds of parameters. Reference character
19
c
denotes a communication procedure for modem training. Reference character
19
d
denotes a communication procedure for setting a modem parameter. Reference character
19
e
denotes a communication procedure for exchanging a facsimile control signal. And, reference character
19
f
denotes a data communication procedure for the primary channel. The upper side in the diagram is a sequence for a caller modem, and the lower side is a sequence on an answer modem, and the sequences progress from left to right.
The above communication protocols will be specifically described as follows:
First, in the communication procedure
19
a
for selecting a modulation mode, the selection of a modulation mode and communication procedure, which permit communication between a caller modem and an answer modem, through a V.21 modem (300 bps, full-duplex), is carried out after a line connection is established. A facsimile apparatus using a V.34 modem selects a V.34 modem as the modulation mode and facsimile communication as a communication procedure.
After that, in the communication procedure
19
b
for line probing, the caller modem transmits a line probing tone. The line probing tone is received by the answer modem, a line inspection is carried out, and a training parameter is selected based on the result of the line inspection.
In the communication procedure
19
c
for modem training, the caller modem sends training signals based on the training parameter selected under the line probing communication procedure
19
b
, while the answer modem receives the training signals, learns a filter coefficient for an adaptive equalizer for compensating the line characteristic and checks the reception quality of the training signals.
In the communication procedure
19
d
for selecting a modem parameter, modem parameters are negotiated between the caller modem and the answer modem in full-duplex communication at 1200 bps. As a result, an optimal modem parameter is selected from the modem parameters preset in the apparatus, the result of the line inspection and the inspection of the reception quality of the training signals.
In the communication procedure
19
e
for a facsimile control signal, negotiation of facsimile control signals NSF, CSI, DIS, TSI, DCS, CFR, etc. is executed in full duplex communication at 1200 bps.
Then, in the data communication procedure
19
f
, image data is transmitted from the caller modem in half-duplex communication at 2400 bps to 33.6 kbps. Image data is received by the answer modem. In the case of performing communication at the maximum communication rate of 33.6 kbps, image data can transmit in approximately three seconds per a sheet of paper of size A4.
The caller and answer modes, which execute the aforementioned communication protocol, carry out communication in accordance with the training parameter selected under the communication procedure
19
b
for communication line probing and the modem parameter selected under the communication procedure
19
d
for selection of a modem parameter. To compensate the line characteristic, the receiver modem executes communication using the filter coefficient that has learned in the modem training
19
b
. This ensures optimal data communication according to the line quality.
However, the above-described prior art structure involves five channels of a procedure before starting sending image data after line establishment, and thus requires about 7 seconds. By contrast, since electric transmission of a single sheet of image data at the maximum communication rate of 33.6 kbps takes about 3 seconds, the procedures requires over 60% of the entire time of 11 seconds required for transmission of one sheet of an original including the later-procedure about 1 second. This time needed for the previous-procedure gets greater as the number of transmission/reception lines increases, and generates wasteful time and communication cost.
DISCLOSURE OF INVENTION
In consideration of the above-mentioned problems, an object of the present invention is to provide a data communication apparatus which can shorten time for setting various kinds of parameters of a modem and time for a previous-procedure including time for modem training before the image transmission.
Also, an object of the present invention is to provide a data communication apparatus such that a supported short previous-procedure function appropriately operates even when a communication error rate is high or line characteristics are changed.
More specifically, there is provided a data communication apparatus comprising:
storing means for storing various kinds of modem control information for each destination in association with an operation key;
calling means for generating a call to said destination by-a transmission command from said operation key to start communication; and
communication control means for transmitting a shift notify signal indicative of the shift to a previous-procedure for short communication in a case of communication using said calling means, thereafter controlling the modem based on said various kinds of control information so as to shorten a previous-procedure and carry out data transmission.
The data communication apparatus according to the first aspect of the present invention comprise storing means for storing various kinds of modem control information for each destination in associate with an operation key,
calling means for generating a call to said destination by a transmission command from said operation key to start communication; and
communication control means for transmitting a shift notify signal indicative of a shift to a short previous-procedure in a case of communication using said calling means, thereafter controlling the modem based on said various kinds of control information so as to shorten a previous-procedure and carry out data transmission.
According to the above-mentioned structure, communication to the destination registered in the operation key is executed in the short previous-procedure based on control information stored in storing means, so that an operator can shorten communication time by considerably simple operation. Since it is unnecessary to obtain modem control information suitable for the destination by communication in the previous-procedure, time required for a previous-procedure can be greatly shortened. Control information described here is time for modem parameter or modem training.
The second aspect of the present invention, in the data communication apparatus of the first aspect, the communication control means transmits the shift notification signal that indicates shift to a short previous-procedure in place of a calling menu signal, in response to a deformed answer signal from an answer side apparatus with respect to a calling signal transmitted in previous-procedure configu
Eng George
Greenblum & Bernstein P.L.C.
Panasonic Communications Co. Ltd.
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