JP3546563B2 - Facsimile machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a facsimile apparatus, and more particularly, to a facsimile apparatus capable of improving line use efficiency.
[0002]
[Prior art]
The G4 facsimile communication protocol is divided into seven layers in the OSI reference model. The facsimile apparatus has an independent control program corresponding to each layer in the communication control apparatus, and there is an interface between each control program for data transfer, protocol indication and notification, and the like. In data transmission, all data of layer 3 or higher is provided with a header and passed to a lower layer, and the data is supplied with a header and passed to a lower layer.
[0003]
For transmission of image information represented by a continuous octet string in page units, X.X.X is used for exchange of a document application profile defined in ITU-T T.503. The transfer syntax encoding rules defined in 209 apply. The image information is transmitted to ASN. 1 and encoded according to the transfer syntax encoding rule, and incorporated into the user information field of the session / document command CSUI / CDUI.
[0004]
FIG. FIG. 3 is a diagram illustrating an example of encoded data according to No. 1; In the figure, the transmitted document information D is converted into encoded data CD according to an abstract syntax and a transfer syntax rule based on the abstract syntax as shown in FIG. Of the encoded data CD, “04 Len XXX (t. 6 columns) XXX” is the actual image data and its header. The code (t.6 column) is the T. Code in which the image defines the MMR coding. It indicates that it is encoded according to Recommendation 6. The length field (Len) representing the length of the image data is specified as a maximum of 3 octets. Therefore, the maximum length of the image data is 64K (65535) octets. Note that the transmission data is already ASN. In the case of transmission data that has been appropriately encoded and stored in the memory means, or is code data that is not image information, that is, transmission data for file transfer, these data transmissions are performed in session / document. It is stored directly in the user information field of the command CSUI / CDUI.
[0005]
FIG. 8 is a schematic diagram showing a mode of data division when transmission data incorporated in the session layer (layer 5) is passed to the transport layer (layer 4) and further to the network layer (layer 3). The encoded data CD is incorporated in a user information field of a session / document command CSUI / CDUI. The data of the user information field is added to a header Hcsui / cdui (4 octets of information) and passed to the transport layer. At this time, data including the header Hcsui / cdui is divided according to the maximum size of the information field of the transport data TDT. In the example of the figure, it is divided into two. The default of the block length of the transport data TDT is 128 octets including the header Htra (3 octets), but options of 256, 512, 1024, and 2048 octets can be selected by negotiation.
[0006]
Further, the transport data is passed to the network layer and divided into the size of the information field of the data packet. Excluding the header, the information field of the network layer has a length of 128, 256, 512, 1024, 2048, and 4096 octets, and can be selected by negotiation as in the case of the transport data TDT.
[0007]
Since the size when the image data to be transmitted is incorporated in the user information field of the session / document command CSUI / CDUI, that is, the block size, is not specifically defined, one appropriate value generally within 64K octets is set. Or determine a value such that all session / document commands are included in the transport data according to the negotiation size of the transport layer.
[0008]
[Problems to be solved by the invention]
If the block size of the image data is determined as described above, the following problems may occur. First, when one appropriate value within 64K octets is set, there are the following problems. For example, when 2048 octets are set as one of the sizes of the transport data TDT, and the block size of the image data is determined in accordance with this, 2037 octets are selected in consideration of the header size. That is, the header Htra added to the transport data TDT is 3 octets, the header Hcsui / cdui added to the session / document command CSUI / CDUI is 4 octets, and the header Happ of the encoded image data in FIG. 7 is 4 octets. And these sum up to 11 octets. Therefore, the total length of the block of image data is determined to be 2037 octets so that the actual data part Pix of the image data and 10 octets of the header size are totaled to be 2048 octets.
[0009]
However, even if the block size of image data is determined in this way, if the block size is finally determined to be 1024 octets by transport negotiation, for example, the transport data TDT is as shown in FIG. Splitting occurs. That is, the data of 2037 octets is divided into three blocks (three stages in FIG. 9). As a result, an inefficient block TDT (3) in which the 3-octet header Htra is added to the 3-octet actual data Pix is generated. Such transmission data reduces the efficiency of use of the line.
[0010]
On the other hand, when the division size of the image data is determined according to the result of the transport negotiation, there are the following problems. FIG. 10 is a correspondence diagram between the block size TDBS of the transport data TDT determined based on the result of the negotiation and the block size of the image data matched to the transport data block size TDBS. The calculation formula is also described in the block size. The block size of image data is ASN. 1 and t. This is the size for assembling as 6 rows. In the figure, for example, when the TDBS is 2048 octets, the division size of the image information (the division size of the actual data) is set to 2037 octets. This 2037 octets is a numerical value obtained by subtracting the header of 11 octets from 2048 octets. Similarly, in the case of 1024, 512, 256, and 128 octets, the size of the actual data is determined as illustrated.
[0011]
When the image data is divided in such a size, the inefficient fraction block TDT (3) as in the above example does not occur, but the protocol headers of all layers, that is, Htra, Hcsui, are included in each frame. Since / cdui and Happ are included, the size of the header portion increases in the entire transmission data, and the line use efficiency decreases. In the example of division shown in FIG. 9, the headers of all layers are added to the first block of the three blocks, but only the transport layer header Htra is added to the remaining two blocks. The fact that the header portion becomes large does not matter.
[0012]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a facsimile apparatus which can solve the above-mentioned problems and can improve line use efficiency.
[0013]
[Means for Solving the Problems]
The present invention for solving the above-mentioned problems and achieving the object is an ASN. In a facsimile apparatus configured to divide the transmission data or the transmission data for file transfer appropriately coded in 1 and issue a transmission instruction to a lower layer, the blocking size of the transmission data is set to “2N ( 7) .Ltoreq.N.ltoreq.16 ) octet "and a block size setting means for setting and registering, a negotiation means for determining a transport data block size by negotiation of a transport layer, and the registered block size (S). If the block size (TDBS) determined in the negotiation is larger than the above, the registered block size (S) is determined as the actual block size (T), and the registered block size (T) is determined. Is greater than or equal to the block size determined in the negotiation In this case, a first feature is that a block size calculating unit that calculates an actual block size (T) by the calculation formula 1 and a dividing unit that divides transmission data according to the calculated block size are provided. There is. Calculation formula 1 is as follows. T = S- (mxHtra + Hcsui / cdui). Here, m = S / TDBS, Htra = header size of transport data block, Hcsui / cdui = header size of session / document user information command.
[0014]
Further, the present invention includes a partner device determining means for determining whether or not the transmitting partner device is the same model as the own station. If the partner device is not the same model, the blocking size (T) is calculated by Expression 2. A second feature is that a calculation formula to be calculated is further provided in the block size calculation means. Calculation formula 2 is as follows. T = TDBS-Htra - Hcsui / cdui.
[0015]
Further, according to the present invention, the transmission data is ASN. If the data is not encoded in T.1, the T.1 encoded in the abstract syntax notation. The block size is obtained by subtracting the header size (Happ) required for code conversion of the encoded data of six columns by the transfer syntax rule from the calculated block size (T) to obtain the block size (T). There is a third feature in that the calculation means is configured.
[0016]
According to the above feature, the block size of the image data is determined in accordance with the block size of the transport data determined by the negotiation so that a block having a small size does not occur.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a block diagram showing a hardware configuration of the facsimile apparatus according to one embodiment of the present invention. In FIG. 1, an image storage device 1 is for storing transmission originals and received image information read by a reading device 2, and is a large-capacity storage device such as a DRAM or a hard disk. The image processing device 3 encodes or decodes image information and enlarges or reduces image information. The image information read by the reading device 2 is compressed by the image processing device 3 and stored in the image storage device 1. The printing device 4 prints out the image information read from the image storage device 1 and decompressed by the image processing device 3 and outputs it as a hard copy.
[0018]
The facsimile device further has communication control units 5 and 6, a modem 7, a digital network control device 8 and an analog network control device 9 as facsimile communication functions. The modem 7 is a modem having low-speed mode and high-speed mode functions, the analog network controller 9 is a device having a function of connecting to an analog network, and the digital network controller 8 is a function of connecting to a digital network such as an ISDN network. It is an apparatus provided with.
[0019]
The communication control unit 5 is a device for communication control suitable for digital networks such as G4, and the communication control unit 6 is a device for communication control suitable for analog networks such as G3. The substance of the communication control units 5 and 6 is a ROM storing a program.
[0020]
The above components are connected to the system bus 10 and controlled by the operation of the CPU 12 according to a program stored in the system control unit 11 in advance. The RAM 13 is used for storing control data for control by the CPU 12 and as a work area. The operation display device 14 includes an input unit including keys for an operator to input an instruction, and a display unit for displaying a result processed by the CPU 12 according to the instruction and the like. The display unit can be constituted by a known display means such as a liquid crystal panel.
[0021]
Next, the operation of the facsimile apparatus having the above configuration at the time of transmission will be described with reference to the flowchart of FIG. The contents of communication between the transmitting side and the receiving side corresponding to the operation of the flowchart are shown in the sequence diagram of FIG. In FIG. 3, in step S1, it is determined whether or not there is a transmission request. If a transmission request is input from the operation display device 14, for example, the process proceeds to step S2 to execute a line (channel) connection process. It is determined in step S3 that the connection has been completed. If the channel connection has been completed, the process proceeds to step S4. In step S4, a data link connection process of layer 2 is executed. It is determined in step S5 that the connection has been completed. If the connection has been completed, the process proceeds to step S6. In step S6, a layer 3 network (IS8208) connection process is executed. It is determined in step S7 that the connection has been completed. If the connection has been completed, the process proceeds to step S8. In step S8, a layer 4 transport connection process is executed. It is determined in step S9 that the connection has been completed, and if the connection has been completed, the process proceeds to step S10. In step S10, the size of the transport data TDT selected by the layer 4 negotiation is set in the parameter TDBS. Hereinafter, the parameter TDBS is referred to as a nego size TDBS.
[0022]
Subsequently, the process proceeds to the process of FIG. 4, and in step S11, a layer 5 session connection process is executed. It is determined in step S12 that the connection has been completed, and if the connection has been completed, the process proceeds to step S13. In step S13, it is determined whether or not the transmission partner is the same model as the transmitter. If they are the same model, the process proceeds to step S14, and it is determined whether or not the value of the nego size TDBS is larger than the parameter S. The parameter S is a transmission data division size (referred to as a setting block size) arbitrarily set under the condition of 2 N (7 ≦ N ≦ 16). If the nego size TDBS is larger than the set block size S, the process proceeds to step S15, where the set block size S is actually incorporated into the user information field of the session / document command CSUI / CDUI. T). For example, if the set block size S is 1024 octets and the nego size TDBS is 2048 octets, 1024 octets will be the determined block size T. ASN. The transmission data appropriately encoded in step S1 and stored in the image information storage device 1 is divided into blocks in units of 1024 octets and incorporated into the user information field of the session / document command CSUI / CDUI.
[0023]
On the other hand, if the determination in step S14 is negative, that is, if the set block size S is equal to or larger than the nego size TDBS, the process proceeds to step S16 to calculate the determined block size T. The formula for calculating the determined block size T is “T = S− (m × Htra + Hcsui / cdui)”. Here, it is assumed that m = S / TDBS. For example, when the set block size S is equal to the nego size TDBS, m = 1, so the determined block size T is a value obtained by subtracting the header Htra and the header Hcsui / cdui from the set block size S. .
[0024]
If the set block size S is larger than the nego size TDBS, for example, if the set block size S2048 octets and the nego size TDBS are 512 octets, m = 4, so the determined block size T is the set block size S Is a value obtained by subtracting the size of the header Htra four times the size of the header Htra and the header Hcsui / cdui. That is, data having a setting block size S of 2048 octets is divided into four blocks, one of which has a header Htra and a header Hcsui / cdui added thereto, and the other three blocks each have only the header Htra. Is added. Therefore, the data size included in the transport information field is determined by subtracting the size of all the headers from the set block size S.
[0025]
In step S17, data is cut out using the determined block size T and stored in the user information field of the session / document command CSUI / CDUI. In step S18, transmission is instructed to the lower layer, that is, the transport layer. It is determined in step S19 whether or not the transmission has been completed. If the transmission has been completed, the process proceeds to step S20, where disconnection processing of each layer is performed. In step S21, a line (channel) disconnection process is performed.
[0026]
Further, if it is determined in step S13 that the transmission destination stations are not the same model, the process proceeds to step S22, where the determined block size T is set to a value obtained by subtracting the header Htra and the header Hcsui / cdui from the nego size TDBS. That is, when the partner device does not accept the data in the divided format, that is, the data may not be accepted unless it is the transmission data assembling method described in the second example of the prior art (FIG. 10). The division format is such that the header Htra and the header Hcsui / cdui are added. As a result, it is possible to prevent communication from being disabled even when the transmission destination is not the same model.
[0027]
The above description of the operation has already been made in ASN. 1 or transmission data in a file format. On the other hand, when the transmission data is only facsimile-coded, the header Happ of the image data is included. Therefore, the size of this header Happ, that is, a value obtained by further subtracting 3 octets from the nego size TDBS, is determined as the block size Must be T. FIG. 5 shows a process of calculating the block size T by a calculation formula for further subtracting the size of the header Happ (steps S16a and 22a), and dividing the divided data into ASN. 6 is a flowchart including a process (Step S17a) of incorporating the information into the information field of the session / document command CSUI / CDUI into the transfer syntax of No. 1 and the same step numbers as those in FIG.
[0028]
Subsequently, the main function of the present invention in this embodiment for determining the determined block size T will be described. In FIG. 1, a set block size S for dividing transmission data is registered in a block size setting unit 15. The set block size S is represented by octets, and can be set to any value determined by 2 N (7 ≦ N ≦ 16). (7 ≦ N ≦ 16) is determined according to JT-T521 and T.T. According to 70 recommendations. The block size negotiation unit 16 determines the block size of the transport data TDT in the transport layer by negotiation with the partner station. The block size determined in the negotiation is referred to as a negotiation size TDBS as described above. The nego size TDBS and the set block size S are input to the comparing unit 17.
[0029]
The comparison unit 17 compares the nego size TDBS with the set block size S, and inputs the magnitude relationship to the block size calculation unit 18. The block size calculation unit 18 calculates the determined block size T by selecting the calculation formula of step S15, S16 or S16a of the above-described flowchart according to the comparison result from the comparison unit 17. The dividing unit 19 divides the transmission data according to the calculated block size T and incorporates the data into the session / document command.
[0030]
In addition to the comparison result of the comparison unit 17, the block size calculation unit 18 selects a calculation formula according to the determination result when the transmission partner device is determined to be a different model based on the determination result of the partner device determination unit 20. Calculate the determined block size T. The calculation formula at this time is shown in steps S22 and S22a of the above-described flowchart.
[0031]
【The invention's effect】
As apparent from the above description, according to the first to third aspects of the present invention, the transmission data is divided by the blocking size determined according to the block size of the transport layer, so that a fractional block is generated. Absent. Therefore, the use efficiency of the line can be improved, and the communication time can be reduced.
[Brief description of the drawings]
FIG. 1 is a functional block diagram of a main part of a facsimile apparatus according to an embodiment.
FIG. 2 is a block diagram showing a hardware configuration of a control unit of the facsimile apparatus according to the embodiment.
FIG. 3 is a flowchart showing a transmission operation according to the embodiment.
FIG. 4 is a flowchart showing a transmission operation according to the embodiment.
FIG. 5 is a flowchart showing a transmission operation according to the embodiment.
FIG. 6 is a sequence diagram showing a transmission protocol.
FIG. 7 is a diagram illustrating an example of encoded data.
FIG. 8 is a diagram showing a frame configuration for each layer according to the related art.
FIG. 9 is a diagram showing an example of division of transmission data according to a conventional technique.
FIG. 10 is a diagram illustrating another example of division of transmission data according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image storage device, 2 ... Reading device, 15 ... Block size setting part, 16 ... Block size negotiation part, 17 ... Comparison part, 18 ... Block size calculation part, 19 ... Division part, 20 ... Counterpart device discrimination part

Claims (3)

ASN. In a facsimile apparatus configured to divide transmission data or transmission data for file transfer appropriately encoded in 1 and issue a transmission instruction to a lower layer,
Block size setting means for setting and registering a block size of the transmission data in a range of “2 N ( 7 ≦ N ≦ 16 ) octets”;
Negotiation means for determining a block size of transport data by negotiation of a transport layer,
If the block size (TDBS) determined in the negotiation is larger than the registered block size (S), the registered block size (S) is used as the actual block size (T). If the determined block size is greater than or equal to the block size determined in the negotiation, a block size calculation unit that calculates the actual block size (T) using Equation 1;
A facsimile apparatus comprising: a dividing unit that divides transmission data according to the calculated block size.
T = S− (m × Htra + Hcsui / cdui) Formula 1
Here, m = S / TDBS, Htra = header size of transport data block, Hcsui / cdui = header size of session / document user information command. Equipped with a partner device determining means for determining whether the transmitting partner device is the same model as the own station,
2. The facsimile apparatus according to claim 1, wherein, when the partner machines are not the same model, a calculation formula for calculating the block size (T) by the calculation formula 2 is further provided in the block size calculation means.
T = TDBS-Htra - Hcsui / cdui Formula 2 The transmission data is ASN. If the data is not encoded in T.1, the T.1 encoded in the abstract syntax notation. The block size is obtained by subtracting the header size (Happ) required for code conversion of the encoded data of six columns by the transfer syntax rule from the calculated block size (T) to obtain the block size (T). 3. The facsimile apparatus according to claim 1, wherein said facsimile apparatus comprises a calculating means.

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