JP3767000B2 - Communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication apparatus that performs communication using an abbreviated protocol, and more particularly to a communication apparatus that performs communication by determining a transmission rate of image information according to a line state.
[0002]
[Prior art]
Conventionally, in a communication apparatus such as a facsimile apparatus, much time is required for the fallback procedure for determining the transmission speed of image information.
[0003]
Various proposals have been made to shorten the fallback procedure.
[0004]
For example, Japanese Patent Laid-Open No. 3-154566 sends a 300 bps NSS (non-standard function setting signal) when detecting polarity inversion on the receiving side, and detects CED (called terminal identification signal) without detecting polarity inversion. A CED is stopped with a tone, and a 300 bps NSS is transmitted. As a result, the NSF (non-standard function identification signal) is omitted, so that the NSF FIF (facsimile information field) of the partner machine is stored at the time of the first communication, and the communication parameters are negotiated with the stored contents. Determine. The transmission speed of the image information is stored on the transmission side, and the speed is notified. As for the transmission speed of image information, a transmission speed history is stored on the transmission side, and the image information is transmitted at that speed. Transmission of TCF (training check) is omitted, and when CFR (reception preparation confirmation signal) is received, image information is transmitted at the notified speed.
[0005]
In this method, 300 bps NSF is omitted and TCF transmission is also omitted, so the previous protocol time can be shortened considerably. However, since the image information is communicated at the communication speed performed before that, the line status is If it fluctuates, it may cause interruption of transmission or image error. In addition, it is necessary to store the NSF FIF of the other party in the first communication, and it is also necessary to store a history of the communication speed, which is stored for each partner, leading to an increase in cost.
[0006]
In Japanese Patent Laid-Open No. 5-219334, when a CED is detected, the calling party sends a unique tone (DTMF) to stop the CED, and sends a 300 bps NSF for a shortened protocol (an NSF with some required capabilities omitted). To do. The original tone also functions to notify the transmission speed of image information. The image information parameters are transmitted at high speed before the image information at the speed notified by this unique tone, and then the image information is transmitted.
[0007]
In this method, image information is sent out to the 300 bps NSF at high speed. Therefore, in order to notify the transmission speed, the calling side can first notify the receiving side of the communication speed of the image information with a unique tone. However, there is a problem that there is no fallback procedure in the procedure of sending image information parameters at high speed before the image information and then sending out the image information. Considering the fallback procedure, it is necessary to consider command exchange at high speed. In addition, since the image information is transmitted at a predetermined transmission rate, there is a possibility that transmission may be interrupted or an image error may occur when the line state fluctuates. In addition, the communication speed needs to be stored in the first communication, and is stored for each destination, leading to an increase in cost.
[0008]
In JP-A-61-89770, transmission speed history is stored on the transmission side or reception side, and the fallback procedure is executed using the same or higher speed as the trial speed to determine the transmission speed of image information. To do.
[0009]
Also in this method, since the execution speed of the fallback procedure is determined based on the transmission speed of communication performed previously, fallback is likely to occur when the line state fluctuates. In addition, the communication speed needs to be stored in the first communication, and is stored for each destination, leading to an increase in cost.
[0010]
In Japanese Patent Laid-Open No. 2-92153, based on the reception state of a TCF (training check) signal received from the transmission side, an n (n> 0) stage fallback or fall-up instruction is given from the reception side to the transmission side.
[0011]
In this method, in some cases, it is necessary to execute a fallback procedure similar to that of normal communication, and the shortening effect is reduced.
[0012]
In Japanese Patent Laid-Open No. 3-68262, the calling party sends a tone after detecting the CED (called terminal identification signal), and the called party detects the tone and stops the CED. The calling side measures the length of the CED, and if it is smaller than the threshold value, sends the NSS at a high speed. In this method, negotiation in the pre-procedure is omitted and NSS is transmitted at high speed, so communication is performed using communication parameters (paper size, line density, compression method, etc.) determined in advance on the transmission side and reception side. Also, the start speed is determined in advance for the high-speed NSS communication speed, and retransmission is performed each time an error occurs. When an error occurs a specified number of times, communication is performed with a fallback from 9600 bps to 7200 bps, for example.
[0013]
Since this method transmits NSS and image information at a predetermined transmission rate, if the transmission rate does not match the state of the line, transmission is interrupted or an image error occurs, and retransmission and fallback operations are useless. May consume time. Moreover, it is necessary to memorize | store the transmission speed of communication, and it leads to a cost increase.
[0014]
As described above, there are still problems in the conventional procedure for determining the communication speed, and there is a possibility that the procedure for determining the communication speed can be shortened more than before by improving this procedure.
[0015]
[Problems to be solved by the invention]
As described above, there are still many problems with the method for determining the communication speed in a communication apparatus such as a conventional facsimile apparatus.
[0016]
[Problems to be solved by the invention]
  Therefore, in order to solve such a problem, the present invention eliminates fallback by transmitting a command signal on the transmission side and determining the transmission speed of the image information by the identification signal from the reception side in response to this. The purpose is to reduce the time required to determine the transmission rate.
[0017]
[Means for Solving the Problems]
  In order to achieve the above object, a communication apparatus according to claim 1 is a communication apparatus having a transmission / reception means for transmitting / receiving a facsimile signal between a transmission side apparatus and a reception side apparatus via a public line. The apparatus obtains in advance a table indicating a reception state for each line state corresponding to a plurality of transmission rates, and the transmission / reception meansFor a specific transmission rateA transmission rate determining means for determining a line state based on reception of an NSS (non-standard function setting) signal and determining a maximum allowable transmission rate of transmission / reception by the transmission / reception means by referring to the table based on the determined line state; Control means for setting information on the maximum allowable transmission speed determined by the transmission speed determination means to an NSF (non-standard function identification) signal and transmitting the NSF (non-standard function identification) signal by the transmission / reception means. It is characterized by.
[0018]
  Further, the communication device of the invention of claim 2 is the invention of claim 1,The transmission rate determining means includes channel quality judgment data storage means for previously collecting and storing line quality judgment data for discriminating a line state for each of a plurality of transmission speeds, and an NSS (non-standard) of a specific transmission speed by the transmission / reception means. (Function setting) circuit quality determination data extraction means for extracting line quality determination data in the signal reception process, and the line quality determination data storage means based on the line quality determination data extracted by the line quality determination data extraction means The line state is determined with reference to FIG.
[0019]
  The communication device of the invention of claim 3In the first or second aspect of the invention, the transmission-side device includes a control unit that sets a transmission rate based on information on a maximum allowable transmission rate included in the NSF (non-standard function identification) signal received by the transmission / reception unit. It is characterized by comprising.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a facsimile apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
[0028]
FIG. 1 is a block diagram showing the configuration of a facsimile apparatus in which the present invention is implemented.
[0029]
In FIG. 1, 1 is a CPU that controls the entire apparatus, 2 is a RAM that is a work area used by the control program, 3 is an operation display device for operating the apparatus, 4 is a reading device that reads a transmitted document, and 5 Printing device for recording received images, etc. 6 is an image processing device for encoding, decoding, enlargement, reduction, etc. 7 is an image storage device for storing image information, 8 is a ROM for storing a program for controlling the device The system control unit 9 includes a ROM that stores a program for controlling communication suitable for a digital network, and the communication control unit 1 and 10 includes a ROM that stores a program for controlling communication suitable for an analog network. Communication control units 2 and 11 are digital network control devices for connecting communication to a digital network, 12 is a modem as a modem, and 13 is an application for connecting communication to an analog network. A log network controller having an automatic outgoing / incoming function, 14 is a system bus for exchanging data between functional blocks, and 15 is a line switch for connecting a plurality of external line interfaces and a plurality of internal communication lines. It is a control device.
[0030]
The CPU 1 reads a program from the ROM of the system control unit 8 when the power to the apparatus is turned on, and controls the entire apparatus by sending a control command to each component via the system bus 14 based on this program.
[0031]
The RAM 2 operates as a work area for the CPU 1.
[0032]
The operation display device 3 is constituted by a so-called touch panel or the like, and is input / output means for inputting an instruction to the device by touching the panel and displaying the current state of the device.
[0033]
The reading device 4 irradiates and scans a transmission original or a copy original with white light, quantizes the intensity of the reflected light, and converts it into a digital image signal.
[0034]
The printing device 5 prints out the received image signal on a recording sheet.
[0035]
The image processing device 6 encodes transmission data and decrypts reception data. Further, the transmission / reception data is enlarged or reduced as necessary.
[0036]
The image storage device 7 is a storage device that digitally stores image data of a document read by the reading device 4 and received image data for each file.
[0037]
The system control unit 8 is composed of a ROM that stores a control program for the CPU 1 that controls the apparatus. When the power to the apparatus is turned on, the program is read from the ROM by the CPU 1.
[0038]
The communication control unit 1 (9) is a control circuit for controlling the digital network control device 11 and executing a communication protocol suitable for the digital network, and has a ROM for storing a program for digital communication control therein. Yes.
[0039]
The communication control unit 2 (10) is a control circuit for controlling the analog network control device 13 and executing a communication protocol suitable for the analog network, and has a ROM for storing a program for analog communication control therein. Yes.
[0040]
The digital network control device 11 is a control device for accessing the digital network and controlling connection / disconnection of communication with the other communication device or detecting digital communication data.
[0041]
The modem 12 changes the analog data detected by the analog network to digital data and inputs the digital data to the device via the line switching device 15, and changes the digital data from the line switching device 15 to analog data to change the communication control unit 2 ( It plays the role of sending to 10).
[0042]
The analog network control device 13 is a control device for accessing the analog network and controlling connection / disconnection of communication with the other communication device or detecting analog communication data.
[0043]
The system bus 14 is a bus for transmitting / receiving data between the functional blocks constituting the communication device or for transmitting a control command.
[0044]
The line switching control device 15 is a switching circuit for selecting and switching between the digital network and the analog network to access and communicate, and is connected to the digital network control device 11 and the analog network control device 13. Are controlled.
[0045]
This facsimile apparatus is connected to the same apparatus as this apparatus through a communication network, to an apparatus that can be connected to only an analog network, or to an apparatus that can be connected to only a digital network, and performs facsimile communication therebetween. When this device is connected only to the analog network, the communication control unit 1 (9) and the digital network control device 11 can be omitted. When this device is connected only to the digital network, the communication control unit 2 (10) The modem 12 and the analog network control device 13 can be omitted.
[0046]
A basic transmission-side protocol procedure of the shortening protocol of the facsimile apparatus having such a configuration will be described with reference to FIGS.
[0047]
FIG. 2 shows a control flowchart of the transmission protocol of the facsimile apparatus of this embodiment.
[0048]
  First, when a call is made to the partner machine (step 101), it is checked whether or not this partner machine stores the short protocol reception capability (step 102).
  Here, whether or not the partner machine has the shortened protocol reception capability1Are stored in advance in the destination data list stored in a predetermined storage area of the RAM 2 in correspondence with, for example, the abbreviated number of the counterpart device.
[0049]
That is, in step 102, the destination data list in the RAM 2 is searched based on the abbreviated number of the calling party device, and it is checked whether or not the other device is stored as having a shortened protocol reception capability.
[0050]
Then, if it is stored that the partner apparatus has a shortened protocol reception capability (YES in step 103), transmission phase A is executed (step 112). Details of the transmission phase A will be described later with reference to FIG.
[0051]
When the transmission phase A ends, it is determined whether or not the transmission phase A has shifted to the shortened protocol (short professional) transmission (step 113). If the transmission phase A has shifted to the shortened protocol transmission (YES in step 113). Next, transmission phase B is executed (step 114). Details of the transmission phase B will be described later with reference to FIG.
[0052]
When the transmission phase B ends, it is determined whether or not the transmission phase B has shifted to the shortened protocol (short professional) transmission (step 115). If the transmission phase B has shifted to the shortened protocol transmission (YES in step 115). Next, the transmission phase C is executed (step 116). Details of the transmission phase C will be described later with reference to FIG.
[0053]
When the transmission phase C is completed, next, the transmission phase D is executed (step 117). Details of the transmission phase D will be described later with reference to FIG.
[0054]
When the transmission phase D is completed, it is checked whether or not the transmission phase D is shifted to the transmission phase C (step 118). Here, when shifting to the transmission phase C (YES in step 118), the process returns to step 116, and when not shifting to the transmission phase C (NO in step 118), next, in the transmission phase D, to the transmission phase B. It is checked whether or not to move (step 119). Here, when shifting to the transmission phase B (YES in step 119), the process returns to step 114, and when not shifting to the transmission phase B (NO in step 119), a low-speed DCN (disconnect command signal) is sent. This transmission protocol is terminated.
[0055]
  If it is determined in step 103 that the partner device does not have a shortened protocol reception capability, first, 1100 Hz CNG (calling tone) is transmitted (step 104), and then the partner device receives CED (called terminal). (Identification signal) or any command received (step 105). If CED or any command has not been received (NO in step 105), the process returns to step 104, and CNG is sent again. If a CED or any command has been received (YES in step 105), then it is checked whether an NSF (non-standard function identification signal) has been received from the partner machine (step 106), and an NSF has been received. If this is the case (YES in step 106), it is checked whether the received NSF is the company's NSF (step 108), and is the company's NSF. If the information indicating that there is a shortened protocol transmission capability is included in this NSF (step 108), and if the information indicating that there is a shortened protocol transmission capability is included (YES in step 108), Figure above1In the destination data list of the RAM 2 shown in FIG. 2, the fact that there is a shortened protocol reception capability corresponding to the shortened number of the partner machine is stored (step 109), and the process proceeds to step 114 to execute the transmission phase B.
[0056]
  If it is determined in step 106 that no NSF has been received, that is, if a DIS (digital identification signal) has been received (NO in step 106), it is determined that the NSF received in step 107 is not the company's own NSF. If it is determined in step 107 (NO in step 107) or if it is determined in step 108 that the NSF of the company does not include information indicating that there is a shortened protocol transmission capability (NO in step 108),1In the destination data list of the RAM 2 shown in FIG. 6A, it is stored that there is no shortened protocol reception capability corresponding to the shortened number of the counterpart (step 110), normal transmission is performed (step 111), and this transmission protocol is terminated.
[0057]
When it is determined in step 113 that the transmission phase A has not been shifted to the shortened protocol transmission (NO in step 113), or in step 115 it is determined that the transmission phase B has not been shifted to the shortened protocol transmission. (NO in step 115), it is determined that the transmission is normal, and the process proceeds to step 106 to check whether the NSF is received from the partner machine.
[0058]
FIG. 3 shows details of processing in the transmission phase A of step 112 shown in FIG. In this transmission phase A, first, it is checked whether or not the counterpart device has a polarity reversal detection function (step 121). Here, whether or not the counterpart device has a polarity reversal detection function is stored in advance in the destination data list of the RAM 2 shown in FIG.
[0059]
That is, in step 121, the destination data list in the RAM 2 is searched based on the abbreviated number of the calling partner device, and it is checked whether or not the partner device has a polarity reversal detection function.
[0060]
Here, if the counterpart device has a polarity reversal detection function (YES in step 121), a CNG (calling tone) transmission start timer is started (step 127), and then it is checked whether polarity reversal is detected. (Step 127). Here, as will be described in detail later, polarity reversal detection is determined based on whether or not the number of polarity reversals has reached the number of polarity determinations learned during the previous communication with this partner machine. When the number of times of polarity determination learned at the previous communication with the machine has been reached (YES in step 127), the process proceeds to a shortened protocol (short professional) transmission (step 133).
[0061]
If the polarity reversal is not detected in step 127, that is, the number of polarity reversals has not reached the number of polarity determinations learned during the previous communication with this partner (NO in step 127), then CNG transmission is performed. It is checked whether the start timer has timed out (step 128). If the CNG transmission start timer has not timed out (NO in step 128), the process returns to step 127, and if the CNG transmission start timer has timed out (step 128). 128 is YES), CNG (calling tone) is transmitted (step 129), and it is checked again whether polarity inversion is detected (step 130). As will be described in detail later, this polarity reversal detection is also determined by whether or not the number of polarity reversals has reached the number of times of polarity determination learned during the previous communication with this counterpart device. If polarity reversal is detected here, that is, if the number of polarity reversals has reached the number of times of polarity determination learned during the previous communication with this partner machine (YES in step 130), a shortened protocol (short pro) transmission is performed. (Step 133).
[0062]
If no polarity reversal is detected in step 130, that is, if the number of polarity reversals does not reach the number of polarity determinations learned during the previous communication with this partner (NO in step 130), then CED (called) Whether or not the terminal identification signal has been received is checked (step 131). If CED is received (YES in step 131), the process shifts to short protocol (short professional) transmission (step 133).
[0063]
If it is determined in step 131 that no CED has been received (NO in step 131), it is checked whether a low speed command has been received (step 132). If no low speed command has been received (in step 132). NO), returning to step 129, CNG (calling tone) is sent again, and if it is determined that a low speed command has been received (YES in step 132), the routine proceeds to normal transmission (step 125).
[0064]
If it is determined in step 121 that the counterpart device does not have the polarity reversal detection function (NO in step 121), CNG (calling tone) is transmitted (step 122), and then CED (called terminal identification) is sent. It is checked whether or not (signal) has been received (step 123). If CED has been received (YES in step 123), the process proceeds to short protocol (short pro) transmission (step 133).
[0065]
If it is determined in step 123 that no CED has been received (NO in step 123), it is checked whether a low speed command has been received (step 124). If no low speed command has been received (in step 124). NO), return to step 122, send CNG (calling tone) again, and if it is determined that a low speed command has been received (YES in step 124), shift to normal transmission (step 125).
[0066]
FIG. 4 shows details of the processing in the transmission phase B of step 114 shown in FIG. In this transmission phase B, first, it is checked whether or not polling is performed (step 141). If polling is not performed, signal transmission instructing a shift to a shortened protocol (step 142) and high-speed NSS (non-standard function setting signal) transmission are performed. (Step 143) is performed, and then it is checked whether a response is received from the partner machine
(Step 144).
[0067]
If a response is received from the partner machine (YES in step 144), it is then checked whether a high speed NSF (non-standard function identification signal) has been received (step 148). If a high speed NSF is received (step 148) (YES in 148), the process proceeds to a shortened protocol (short professional) transmission (step 150).
[0068]
In step 148, if the high-speed NSF is not received, that is, if a low-speed command such as NSF / DIS is received (NO in step 148), the process proceeds to normal transmission (step 149).
[0069]
If no response is received from the partner machine in step 144 (NO in step 144), it is checked whether polarity inversion is detected (step 145).
[0070]
As will be described later in detail, the detection of polarity reversal here is determined by whether or not the number of polarity reversals has reached the number of times of polarity determination learned during the previous communication with this counterpart device.
[0071]
If no polarity reversal is detected in step 145 (NO in step 145), the fallback parameter is set (step 146), the process returns to step 142, and a signal is sent again to instruct the transition to the shortened protocol (step 142). High-speed NSS (non-standard function identification signal) transmission (step 143) is performed.
[0072]
If polarity inversion is detected in step 147 (YES in step 147), the communication speed of the initial value is reset (step 147), the process returns to step 142, and a signal is sent to instruct the transition to the shortened protocol again. (Step 142), high-speed NSS (non-standard function identification signal) transmission (Step 143) is performed.
[0073]
In other words, if the partner device is equipped with the polarity reversal detection function, it detects polarity reversal even when waiting for a response from the partner device, and if it detects polarity reversal, it sets the initial communication speed. Perform the process again.
[0074]
If it is determined in step 141 that polling is performed (YES in step 141), a signal for instructing a shift to the shortened protocol is transmitted (step 151), and a high-speed NSC (non-standard function command signal) is transmitted (step 152). Next, it is checked whether a response has been received from the partner machine (step 153).
[0075]
If a response is received from the partner machine (YES in step 153), it is then checked whether a high-speed NSS (non-standard function setting signal) is received (step 157). If a high-speed NSS is received (step 157) (YES in 157), the process proceeds to reception phase B described later in FIG. 8 (step 159).
[0076]
In step 157, when the high-speed NSS is not received, that is, when a low-speed command such as NSS / DIS is received (NO in step 157), the process proceeds to normal transmission (step 158).
[0077]
If no response is received from the counterpart device at step 153 (NO at step 153), it is checked whether polarity inversion is detected (step 154).
[0078]
As will be described later in detail, the detection of polarity reversal here is determined by whether or not the number of polarity reversals has reached the number of times of polarity determination learned during the previous communication with this counterpart device.
[0079]
If no polarity reversal is detected in step 154 (NO in step 154), the fallback parameter is set (step 155), the process returns to step 151, and a signal is sent again to instruct the transition to the shortened protocol (step 151). High-speed NSC (non-standard function setting signal) transmission (step 152) is performed.
[0080]
If polarity inversion is detected in step 154 (YES in step 154), the initial communication speed is reset (step 156), the process returns to step 151, and a signal is sent to instruct the transition to the shortened protocol again. (Step 151) and high-speed NSC (non-standard function setting signal) transmission (Step 152).
[0081]
FIG. 5 shows the details of the processing in the transmission phase C of step 116 shown in FIG. In this transmission phase C, it is first checked whether or not the image information is to be retransmitted (step 161). If it is determined that the image information is not to be retransmitted (NO in step 161), NSS ( (Non-standard function setting signal) is sent and sent (step 162), then the picture information is sent in a frame (step 163), and then it is checked whether the picture information has been sent (step 164). If not completed (NO in step 164), the process returns to step 163. If completed (YES in step 164), the content of the post message command is put in an RCP (partial page control return) frame and transmitted (step). 165), and then returns.
[0082]
If the image information is to be retransmitted at step 161 (YES at step 161), the image information to be retransmitted is sent in a frame (step 166), and then it is checked whether the retransmission of this image information has been completed. (Step 167) If not completed (NO in Step 167), return to Step 166. If completed (YES in Step 167), the content of the post message command is displayed in the RCP (partial page control return signal) frame. Put in and send out (step 165), then return.
[0083]
FIG. 6 shows the details of the processing in the transmission phase D of step 117 shown in FIG. In this transmission phase D, it is first checked whether or not a response from the partner device has been received (step 171). If no response has been received (NO in step 171), a low-speed post by PPS-Q or PPS-PriQ is performed. The message command is transmitted and the process returns to step 171.
[0084]
If a response from the partner machine is received in step 171 (YES in step 171), it is then checked whether a low-speed MCF (message confirmation signal) has been received (step 173). If a low-speed MCF is received (step 173). YES), the process proceeds to step 186.
[0085]
If it is determined in step 173 that the low-speed MCF has not been received (NO in step 173), it is then checked whether a low-speed PPR (partial page request signal) has been received (step 174). If a PPR has been received (YES in step 174), it is checked whether CTC (correction continuation signal) needs to be sent (step 177). If necessary (YES in step 177), a low-speed CTC is sent (step 178). When the low-speed CTR (correction continuation response signal) is received (YES in step 179), the process proceeds to the transmission phase C (step 187).
[0086]
If it is determined in step 177 that it is not necessary to send a CTC (correction continuation signal) (NO in step 177), then it is checked whether it is necessary to send an EOR (retransmission end signal) (step 180). If necessary (YES in step 180), low-speed EOR is transmitted (step 181), and if low-speed ERR (retransmission end response signal) is received (YES in step 182), the process proceeds to step 186.
[0087]
If it is determined in step 182 that low-speed ERR (retransmission end response signal) is not received, it is next checked whether low-speed PIN (procedure interruption negative signal) has been received (step 183). (YES in 183), the line hold procedure is performed (step 184), and the process proceeds to step 186.
[0088]
If the low-speed PPR is not received at step 174 (NO at step 174), it is checked whether a low-speed PIP (procedure interruption affirmative signal) is received next (step 175). If the low-speed PIP is received (step 175) (YES in 175), the line hold procedure is performed (step 185), and the process proceeds to step 186.
[0089]
If no low-speed PIP is received at step 175 (NO at step 175), predetermined error processing is performed (step 176), and the process proceeds to step 186.
[0090]
In step 186, it is determined whether the next procedure is any one of the transmission phase C, the transmission phase D, and the transmission phase E based on the sent post message command. If it is determined that the next procedure is the transmission phase C, the process proceeds to the transmission phase C (step 189). If it is determined that the next procedure is the transmission phase D, the process proceeds to the transmission phase D (step 190). When it is determined that it is the transmission phase E, the process proceeds to the transmission phase E (step 191).
[0091]
Next, the reception operation of the facsimile apparatus of this embodiment will be described with reference to the reception protocol control flowcharts shown in FIGS.
[0092]
FIG. 7 is a control flowchart showing the reception protocol of the facsimile apparatus of this embodiment.
[0093]
When there is an incoming call from the partner machine (step 201), a timer of 1.8 seconds is started (step 202), and it is checked whether a signal for instructing a shift to the shortened protocol is received (step 203).
[0094]
If a signal is received (YES in step 203), the reception phase B is first executed. Details of the reception phase B will be described later with reference to FIG.
[0095]
When reception phase B ends, reception phase C is executed next. Details of the reception phase C will be described later with reference to FIG.
[0096]
When reception phase C ends, reception phase D is then executed. Details of the reception phase D will be described later with reference to FIG.
[0097]
When the reception phase D ends, it is checked whether or not the reception phase D is shifted to the reception phase C (step 207). Here, in the case of shifting to the reception phase C (YES in step 207), the process returns to step 205. In the case of not shifting to the reception phase C (NO in step 207), in the reception phase D, the reception phase B (Step 208), if it is the transition to the reception phase B (YES in step 208), the process returns to step 204, and if it is not the transition to the reception phase B (NO in step 208), the reception phase Since it is a transition to E, a low-speed DCN (disconnect command signal) is received (step 209), and this reception protocol is terminated.
[0098]
If it is not determined in step 203 that the signal is not for instructing the shift to the shortened protocol (NO in step 203), then it is checked whether CNG (calling tone) is received (step 210). (NO in step 210), it is checked whether the timer of 1.8 seconds is timed out (step 211). If not timed out (NO in step 211), the process returns to step 203, and if timed out (YES in step 211) , CED (called terminal identification signal) is transmitted (step 212).
[0099]
If it is determined in step 210 that CNG has been received, the process proceeds to step 212, where a CED (called terminal identification signal) is transmitted.
[0100]
When CED is transmitted in step 212, it is checked again whether the signal for instructing the shift to the shortened protocol is received (step 213). Here, when it is determined that the signal for instructing the shift to the shortened protocol is received (YES in Step 213), the CED transmission is stopped (Step 214), and the reception phase B of Step 204 is executed.
[0101]
If it is determined in step 213 that the signal is not received for instructing the shift to the shortened protocol, it is checked whether CED transmission is completed (step 215). If CED transmission is not completed (NO in step 215), step Returning to step 212, when it is determined that CED transmission has been completed (YES in step 215), NSF / DIS is transmitted (step 216), and it is further checked whether a signal for instructing the shift to the shortened protocol is received (step 217). . If it is determined that the signal reception is instructed to shift to the shortened protocol (YES in step 217), the process proceeds to step 204 and the reception phase B is executed.
[0102]
If it is determined in step 217 that the signal is not received for instructing the shift to the shortened protocol (NO in step 217), normal reception is performed (step 218), and this reception protocol is terminated.
[0103]
FIG. 8 shows the details of the processing in the reception phase B of step 204 shown in FIG. In this reception phase B, first, it is checked whether high-speed NSS (non-standard function setting signal) is received (step 211). If a high-speed NSS is received (YES in step 211), a high-speed NSF (non-standard function identification signal) is transmitted (step 222), and the process returns.
[0104]
If the high speed NSS is not received at step 211 (NO at step 211), it is checked whether the high speed NSC (non-standard function command signal) is received (step 223). If the high-speed NSC is not received (NO in step 223), the process returns to step 221. If the high-speed NSC is received (YES in step 223), it is checked whether it is polled OK (step 224). Here, if it is polled OK (YES in step 224), the process proceeds to the transmission phase B shown in FIG. 5 (step 225). If it is not polled OK (NO in step 224), predetermined error processing is executed (step 224). Step 226).
[0105]
FIG. 9 shows the details of the processing in the reception phase C of step 205 shown in FIG. In this reception phase C, it is first checked whether an FCD (facsimile encoded data) frame is received (step 231). If an FCD frame is received (YES in step 231), the NSS of the frame with frame number 0 is checked.
It is checked whether information (non-standard function setting signal) is received (step 232). If it is NSS information reception (YES in step 232), the NSS is analyzed (step 235), and the process returns to step 231.
[0106]
If it is determined in step 232 that NSS information has not been received (NO in step 232), the received image information is stored (step 233), and it is then checked whether frame reception has ended (step 234). If the frame reception has not ended (NO in step 234), the process returns to step 231. If the frame reception has ended (YES in step 234), the process returns.
[0107]
If it is determined in step 231 that the FCD frame has not been received (NO in step 231), the RCP frame is received, so the content of the post message command in this RCP frame is analyzed (step 236), and then Return.
[0108]
FIG. 10 shows details of the process in the reception phase D of step 206 shown in FIG. In this reception phase D, it is first checked whether an RCP (partial page control return signal) frame is received (step 241). If an RCP frame is received (YES in step 241), the process proceeds to step 243. If it is determined in step 241 that an RCP frame has not been received (NO in step 241), then it is checked whether a low speed command has been received (step 242), and if a low speed command is received (in step 242). YES), go to step 243.
[0109]
In step 243, it is checked whether the FCD (facsimile coded data) frame is OK. If the FCD frame is OK (YES in step 243), then it is checked whether it is line hold (step 244). YES in step 244), the line hold procedure is executed (step 246), and the process proceeds to step 256.
[0110]
If it is determined in step 244 that it is not line hold (NO in step 244), a low-speed MCF (message confirmation signal) is sent (step 245), and the process proceeds to step 256.
[0111]
If it is determined in step 243 that the FCD frame is not OK (NO in step 243), a low-speed PPR (partial page request signal) is transmitted (step 247), and then CTC (correction continuation signal) is received. In step 248, when a CTC is received (YES in step 248), a low-speed CTR (correction continuation response) is sent (step 249), and the process proceeds to reception phase C (step 250).
[0112]
If CTC is not received in step 248 (NO in step 248), it is checked whether EOR (retransmission end signal) is received next (step 251). If EOR is not received here (step 251). NO), the process proceeds to reception phase C (step 252).
[0113]
If it is determined in step 251 that an EOR has been received (YES in step 251), then it is checked whether it is line hold (step 253). If it is line hold (YES in step 253), line hold The procedure is executed (step 255) and the process proceeds to step 256.
[0114]
If it is determined in step 253 that the line hold is not set (NO in step 253), a low-speed ERR (retransmission end response signal) is transmitted (step 254), and the process proceeds to step 256.
[0115]
In step 256, it is determined from the received post message command whether the next procedure is reception phase C, reception phase D, or reception phase E (step 256). When it is determined that the next procedure is the reception phase C, the process proceeds to the reception phase C (step 257). When it is determined that the next procedure is the reception phase D, the process proceeds to the reception phase D (step 258). If it is determined that it is the reception phase E, the process proceeds to the reception phase E (step 259).
[0116]
The part related to the mode transition from the basic protocol procedure to the shortened protocol will be described in more detail with reference to the sequence charts shown in FIGS. Here, FIG. 11 to FIG. 13 show basic transmission / reception protocol procedures in three cases of mode transition to the shortened protocol.
[0117]
First, the transmission side will be described.
[0118]
FIG. 11 shows a first case of mode transition to the abbreviated protocol. In this first case, the transmitting side first makes a call (Calling) and stores the transmitting side storage means (FIG. 1). In the RAM 2 (destination data list), it is checked whether or not there is a shortened protocol receiving capability stored in correspondence with the shortened number of the other party (receiving side) (step 103 in FIG. 2). If this is the case, check whether the opposite device (reception side) is equipped with the polarity reversal detection function (step 121 in FIG. 3). If the polarity reversal detection function is implemented, check the polarity reversal. (Steps 127 and 130 in FIG. 3), when polarity reversal is detected, a signal instructing the shift to the shortened protocol is sent (Step 142 in FIG. 4). Migrated, executes simplified protocol.
[0119]
On the other hand, at the receiving side, when a call is received, it is checked whether a signal instructing the transition to the shortened protocol is received from the transmitting side until CED (called terminal identification signal) is transmitted (step 203 in FIG. 7). When a signal instructing the transition to the shortened protocol is received, the transition to the shortened protocol is performed and the shortened protocol is executed.
[0120]
After shifting to the abbreviated protocol, the transmitting side first sends a high-speed NSS (non-standard function setting signal) following a signal indicating the communication speed of the high-speed command (a signal for instructing the transition to the abbreviated protocol) ( Step 143 in FIG. 4) waits for a high-speed NSF (non-standard function identification signal) from the counterpart device (reception side), and receives a high-speed NSF from the counterpart device (reception side) (step 148 in FIG. 4), The process proceeds to the information transmission phase (transmission phase C shown in FIG. 5).
[0121]
When the receiving side receives a high-speed NSS indicated by the signal indicating the communication speed of the high-speed command from the transmitting side (signal for instructing the shift to the shortened protocol) (step 221 in FIG. 8), the receiving side Is sent (step 222 in FIG. 8), and the process proceeds to the image information reception phase (reception phase C shown in FIG. 9).
[0122]
In the image information transmission phase (transmission phase C) on the transmission side, the image information is divided into frames by ECM (error correction mode) and transmitted. Here, the following image information parameters are set in the first frame of the ECM frame, and the image information is inserted into the second and subsequent frames (FCD frames) and transmitted. The first frame may be the content of the NSS sent out first, or only the parameter indicating the image information to be sent out.
[0123]
  When the transmission of the image information is completed in this way, an RCP frame in which the content corresponding to the post message command is set in the facsimile information field is transmitted (step 165 in FIG. 5), and the response is sent.TheThe process proceeds to the command waiting phase (transmission phase D shown in FIG. 6).
[0124]
  In the image information reception phase (reception phase C) on the reception side, the image information divided and transmitted from the transmission side by the ECM frame is received. When the reception of the image information is completed, an RCP frame in which the content corresponding to the post message command is set in the facsimile information field is received, and the content of the post message command of this RCP frame is analyzed (step 236 in FIG. 9). ResponsibleTheThe process proceeds to the command waiting phase (reception phase D shown in FIG. 10).
[0125]
  The sender's responseTheIn the command waiting phase (transmission phase D), when MCF (message confirmation signal) is received (step 173 in FIG. 6), an image information transmission frame (in accordance with the content of the post message command set in the destination RCP frame) It is determined whether to shift to transmission phase C), transmission phase B, or transmission phase E (step 186 in FIG. 6), and shift to each transmission phase is performed.
[0126]
  In addition, the receiver's responseTheIn the command waiting phase (transmission phase D), when an MCF (message confirmation signal) is transmitted (step 245 in FIG. 10), an image information reception frame (in accordance with the content of the post message command set in the received RCP frame) It is determined whether to shift to reception phase C), reception phase B, or reception phase E (step 256 in FIG. 1010), and shift to each reception phase is performed.
[0127]
Then, when the transmission side shifts to the transmission phase E, DCN (disconnect command signal) is sent (step 120 in FIG. 2), and this transmission protocol is terminated.
[0128]
On the receiving side, when the process proceeds to the receiving phase E, the receiving protocol is terminated when the DCN from the transmitting side is received.
[0129]
FIG. 12 shows a second case of mode transition to the shortened protocol. In this second case, the transmitting side first makes a call and also stores the transmitting side storage means (FIG. 1). In the RAM 2 (destination data list), it is checked whether or not it is stored as having a shortened protocol reception capability corresponding to the shortened number of the other party (reception side) (step 102 in FIG. 2). If this is the case, check whether the opposite device (reception side) is equipped with the polarity reversal detection function (step 121 in FIG. 3). If the polarity reversal detection function is implemented, check the polarity reversal. (Step 127 in FIG. 3 and Step 130), and CED (Called Terminal Identification Signal) is detected before detecting the polarity reversal (Step 131 in FIG. 3), By sending a signal for instructing the line shifts to the simplified protocol (step 142 in FIG. 4), to perform the simplified protocol.
[0130]
In addition, when the opposite device (reception side) does not have the polarity reversal detection function, CED detection is performed while sending CNG (calling tone) (steps 122 and 123 in FIG. 3). A signal instructing the shift to is sent (step 142 in FIG. 4), the shift to the shortened protocol is performed, and the shortened protocol is executed.
[0131]
On the other hand, at the receiving side, when a call is received, it is checked whether a signal instructing the transition to the shortened protocol is received from the transmitting side until CED (called terminal identification signal) is transmitted (step 203 in FIG. 7). If the CED must be sent without receiving the signal, the CED is sent (step 212 in FIG. 7), and it is checked whether a signal instructing the transition to the shortened protocol is received while sending the CED. (Step 213 in FIG. 7) When the signal for instructing the shift to the shortened protocol is received, the transmission of the CED is stopped, the shift to the shortened protocol is performed, and the shortened protocol is executed.
[0132]
The processing after shifting to the shortened protocol is the same as that shown in FIG.
[0133]
FIG. 13 shows a third case of mode transition to the abbreviated protocol. In this third case, the transmitting side first makes a call and calls the transmitting side storage means (FIG. 1). In the RAM 2 (destination data list) is checked whether it is stored as having a shortened protocol reception capability corresponding to the shortened number of the other party (receiving side) (step 102 in FIG. 2), and stored as having no shortened protocol receiving capability. If a CED or command is detected while sending CNG (step 105 in FIG. 2) and NSF (non-standard function identification signal) is received (step 106 in FIG. 2), the received NSF is 2 is checked (step 107 in FIG. 2), and in the case of the in-house NSF, it is checked whether it has the ability to receive a shortened protocol (step in FIG. 2). 108) If there is abbreviated protocol reception capability, the storage means (destination data list in RAM 2 in FIG. 1) stores that there is abbreviated protocol reception capability corresponding to the abbreviated number of the other party (reception side) ( Step 109 in FIG. 2), then, a signal instructing the shift to the shortened protocol is transmitted (step 142 in FIG. 4), the shift to the shortened protocol is performed, and the shortened protocol is executed. If the above conditions are not met, transmission is performed using a normal protocol.
[0134]
On the other hand, at the receiving side, when a call is received, it is checked whether a signal instructing the transition to the shortened protocol is received from the transmitting side until CED (called terminal identification signal) is transmitted (step 203 in FIG. 7). If the CED must be sent without receiving the signal, the CED is sent (step 212 in FIG. 7), and it is checked whether a signal instructing the transition to the shortened protocol is received while sending the CED. (Step 213 in FIG. 7) When the CED transmission is completed without receiving the signal, NSF and DIS (CIS if necessary) indicating that the shortened protocol reception capability is available are transmitted (Step 216 in FIG. 7). Further, it is checked whether or not a signal for instructing the transition to the shortened protocol has been received (step 217 in FIG. 7). To run the col. If the above conditions are not met, reception is performed using a normal protocol.
[0135]
The processing after shifting to the shortened protocol is the same as that shown in FIG.
[0136]
The basic part of the three protocol procedures related to the transition to the shortened protocol has been described above, but other procedures (for example, the ECM frame retransmission procedure, etc.) can be performed as shown in FIGS. T Recommendation It operates according to 30.
[0137]
Next, some basic methods for determining the transmission rate of image information will be described.
[0138]
FIG. 14 is a flowchart showing a first method for determining the transmission rate on the receiving side. FIG. 15 is a sequence chart at this time.
[0139]
First, when high-speed NSS reception starts on the receiving side (step 301), line quality determination data is extracted in the process of reception of this NSS (step 302). When reception of the high-speed NSS is completed (step 303), the maximum allowable transmission rate of image information is determined from the extracted line quality determination data (step 304).
[0140]
Next, the determined maximum allowable transmission rate is set in the NSF, this NSF is transmitted to the transmission side (step 305), and the process ends.
[0141]
In order to determine the maximum allowable transmission rate of image information from the line quality determination data extracted in step 304, it is necessary to collect the following data in advance. Here, the speed can be selected from six types of 14.4 kbps, 12.0 kbps, 9600 bps, 7200 bps, 4800 bps, and 2400 bps.
[0142]
  (1) First, as shown in FIG. 16, the line quality judgment data for the line state for each transmission rate is collected.
  Line quality judgment dataThe smaller the number, the better the line condition.
  In the case of 9600 bps, the line state deteriorates in the order of a, b, c, d.
[0143]
(2) Next, as shown in FIG. 17, the reception state for each transmission rate for each line quality determination data is collected. In the figure, the circle mark is good and the x mark is bad. As can be seen from the figure, in the case of 9600 bps, the line state deteriorates in the order of a, b, c, d.
[0144]
In this figure, for example, when the line quality determination data of “3” is extracted in the process of NSS reception of 9600 bps, the reception state is poor at 14.4 kbps from the chart of FIG. 17, but good at 12.0 kbps. I understand that Therefore, the maximum allowable transmission rate of image information in this case is 12.0 kbps.
[0145]
FIG. 18 is a flowchart showing a second method for determining the transmission rate on the receiving side. FIG. 19 is a sequence chart at this time.
[0146]
When high-speed NSS reception starts on the receiving side (step 311), line quality determination data is extracted in the process of reception of this NSS (step 312). When reception of the high-speed NSS is completed (step 313), it is determined whether or not the transmission speed of the high-speed NSS is the maximum speed (9600 bps) (step 314). When it is the maximum speed (9600 bps) (YES in step 314), the maximum allowable transmission speed of the image information is determined from the extracted line quality determination data (step 315). In this case, the maximum allowable transmission rate is one of 14.4 kbps, 12.0 kbps, and 9600 bps. If it is less than the maximum speed (9600 bps) (NO in step 314), the transmission speed of the high-speed NSS is set as the maximum speed of the image information (step 316). In this case, the maximum allowable transmission rate is one of 7200 bps, 4800 bps, and 2400 bps.
[0147]
Next, the determined maximum allowable transmission rate is set to NSF, this NSF is transmitted to the transmission side (step 318), and the process is terminated.
[0148]
In the communication apparatus having the procedure control as described above, specific examples of the control procedure for determining the communication speed on the transmission side will be described below.
[0149]
FIG. 20 is a flowchart of the first embodiment.
[0150]
(1) First, a call is made (step 321), and after dialing, the polarity is reversed and a facsimile signal from the partner machine is detected (step 322).
[0151]
(2) When polarity inversion is detected or a facsimile signal from the partner machine is detected, an instruction for the communication speed (14.4 kbps) is set in NSS (step 323), and a high-speed NSS is sent (step 324). Wait for reception of high-speed NSF, which is a response from.
[0152]
(3) If a high-speed NSF that is a response signal from the partner machine cannot be detected within a certain time (YES in step 333), the communication speed instruction determined excluding the communication speed to be excluded is set in the NSS (step 334), the high-speed NSS is transmitted again at the communication speed determined in accordance with the fallback procedure (step 324), and the reception of the high-speed NSF that is a response from the partner machine is awaited.
[0153]
When a high-speed NSF as a response signal is received, the process proceeds to an image information transmission procedure.
[0154]
(4) While the procedure shown in the above (3) is repeated, polarity inversion is detected or a facsimile signal from the partner machine is simultaneously detected (steps 327 and 328).
[0155]
(5) When polarity reversal is detected in the procedure shown in (4) above, the communication speed (14.4 kbps) is set to NSS by returning to the predetermined communication speed sent when polarity reversal is detected. (Step 332), the high-speed NSS is sent again (Step 324), and the above-described procedures (3) and (4) are repeated. The predetermined communication speed here is generally the initial communication speed (communication speed of the first high-speed NSS: 14.4 kbps), but is not necessarily the communication speed.
[0156]
(6) When a facsimile signal is detected by the procedure shown in (4) above, the communication speed is returned to a predetermined communication speed transmitted when the facsimile signal is detected.
The instruction (14.4 kbps) is set in the NSS (step 332), the high-speed NSS is sent again (step 324), and the above-described procedures (3) and (4) are repeated. The predetermined communication speed here is generally the initial communication speed (communication speed of the first high-speed NSS: 14.4 kbps), but it is not necessarily the communication speed.
[0157]
The facsimile signal here is ITU-T recommendation T.30. 30 is a CED or preamble described in FIG. Among these, for the preamble, the contents of the HDLC frame following the preamble are analyzed, and the ITU-T recommendation T.264 is analyzed. If it is determined that the command is a normal command described in 30, it may be determined that the preamble is received.
[0158]
FIG. 21 is a detailed flowchart of polarity reversal or CED check in step 327 of FIG.
[0159]
In (5) of the example of FIG. 20, when polarity inversion is detected (YES in step 341), the count number is stored in a storage means such as a memory for storing the number of detections (step 342), and the number is preset. (Step 343).
[0160]
If the numbers match as a result of this comparison (YES in step 344), it is assumed that polarity reversal has been detected (step 345). If CED is detected without detecting polarity reversal (NO in step 341) (step 346), CED is detected (step 348).
[0161]
When polarity inversion or CED is detected, the process proceeds to step 332 in FIG. 20, and the high speed NSS is sent again after returning to the predetermined communication speed to be transmitted at the time of polarity inversion or CED detection. 3) The control of (4) is performed. The predetermined communication speed here is generally the initial communication speed (communication speed of the first high-speed NSS: 14.4 kbps), but it is not necessarily the communication speed.
[0162]
FIG. 22 is a detailed flowchart of the preamble check in step 329 of FIG.
[0163]
In (6) of the example of FIG. 20, when a preamble is detected as a facsimile signal (step 351), it is determined whether reception of NSF has been completed (step 352), and storage means such as a memory for storing the number of times the preamble has been detected The count number is stored (step 353), and it is determined whether it is the first time (step 354). In the case of the first time, the process proceeds to step 332 in FIG. 20, the transmission speed is returned to the predetermined transmission speed when the facsimile signal is detected, and the high-speed NSS is transmitted again, and (3) and (4) in the example of FIG. Take control. The predetermined communication speed here is generally the initial communication speed (communication speed of the first high-speed NSS: 14.4 kbps), but it is not necessarily the communication speed.
[0164]
When the number of preamble detections is the second or later, the process proceeds to step 334 in FIG. 20, and the high speed NSS is set to the communication speed determined by excluding the communication speed determined to be excluded in advance, and the high speed NSS is transmitted again. Then, the controls (3) and (4) in the example of FIG. 20 are performed.
[0165]
Here, the communication speed determined to be excluded in advance is considered as follows. For example, if the first high-speed NSS is transmitted at 9600 bps, the response signal does not return to the high-speed NSS. Therefore, it is determined that communication cannot be performed at a communication speed of 9600 bps or higher under this line condition. Therefore, if the maximum speed is a communication device of 14.4 kbps, it is determined that communication cannot be performed at a communication speed in the range of 14.4 kbps to 9600 bps, and the communication speed is determined to 7200 bps by excluding the communication speed in that range in advance. It is.
[0166]
FIG. 23 shows another specific example of the control procedure for determining the communication speed in place of FIG.
[0167]
(1) First, a call is made (step 361), and after dialing, the polarity is reversed and the facsimile signal from the partner machine is detected (step 362).
[0168]
(2) When polarity inversion is detected or a facsimile signal from the partner machine is detected, an instruction for the communication speed (14.4 kbps) is set in NSS (step 363), and a high-speed NSS is sent (step 364). Wait for reception of high-speed NSF, which is a response from.
[0169]
(3) If a high-speed NSF that is a response signal from the partner machine cannot be detected within a certain time (YES in step 369), the high-speed NSS is set to the communication speed determined by excluding the communication speed determined to be excluded in advance. It is set (step 370), high-speed NSS is sent again (step 364), and reception of high-speed NSF which is a response from the partner machine is waited for.
[0170]
Here, the communication speed determined to be excluded in advance is considered as follows. For example, if the first high-speed NSS is transmitted at 9600 bps, the response signal does not return to the high-speed NSS. Therefore, it is determined that communication cannot be performed at a communication speed of 9600 bps or higher under this line condition. Therefore, if the maximum speed is a communication device of 14.4 kbps, it is determined that communication cannot be performed at a communication speed in the range of 14.4 kbps to 9600 bps, and the communication speed is determined to be 7200 bps by excluding the communication speed in that range in advance. It is.
[0171]
In addition, when a signal requesting fallback is received from the receiving side as well as the preamble, the communication speed is determined according to normal fallback control, the communication speed is determined, the high speed NSS is set to the determined communication speed, The high speed NSS is sent again, and the above controls (2) and (3) are performed.
[0172]
FIG. 24 is a flowchart of communication speed determination on the receiving side, which changes to FIG. In FIG. 24, the same step number is assigned to the same function as FIG.
[0173]
(1) When an incoming call is received, reception of a high-speed NSS is waited for (step 311).
[0174]
(2) Next, line quality judgment data is extracted while receiving the high-speed NSS (step 312).
[0175]
(3) When reception of the high speed NSS is completed (step 313), the transmission speed is determined from the speed of the high speed NSS and the line quality determination data (steps 314 to 316). If it cannot be determined (YES in step 381), a response signal indicating that it could not be determined is transmitted (step 382), and a high-speed NSS is awaited.
[0176]
Thereafter, the above (2) and (3) are repeated.
[0177]
【The invention's effect】
As described above, according to the present invention, the communication speed is determined by the response signal from the counterpart device with respect to the test signal for determining the communication speed in the communication device that performs communication using the shortened protocol.
[0178]
This eliminates the need to execute a fallback procedure, suppresses transmission interruptions and image errors, simplifies the apparatus, and shortens the time required to determine the communication speed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a facsimile apparatus according to the present invention.
FIG. 2 is a control flowchart showing a transmission protocol of the facsimile apparatus shown in FIG.
FIG. 3 is a flowchart showing details of processing in transmission phase A in the transmission protocol shown in FIG. 2;
FIG. 4 is a flowchart showing details of processing in transmission phase B in the transmission protocol shown in FIG. 2;
FIG. 5 is a flowchart showing details of processing in transmission phase C in the transmission protocol shown in FIG. 2;
6 is a flowchart showing details of processing in transmission phase D in the transmission protocol shown in FIG. 2;
7 is a control flowchart showing a reception protocol of the facsimile apparatus shown in FIG.
FIG. 8 is a flowchart showing details of processing in reception phase B in the reception protocol shown in FIG. 7;
FIG. 9 is a flowchart showing details of processing in reception phase C in the reception protocol shown in FIG. 7;
FIG. 10 is a flowchart showing details of processing in reception phase D in the reception protocol shown in FIG. 7;
11 is a sequence chart showing a first case of mode transition to a shortened protocol in the facsimile apparatus shown in FIG.
12 is a sequence chart showing a second case of mode transition to the shortened protocol in the facsimile apparatus shown in FIG. 1. FIG.
13 is a sequence chart showing a third case of mode transition to the shortened protocol in the facsimile apparatus shown in FIG. 1. FIG.
14 is an example of a basic flowchart of a receiving side image information maximum allowable transmission rate determination protocol in the facsimile apparatus shown in FIG. 1;
FIG. 15 is a sequence chart for determining a transmission rate corresponding to the flowchart of FIG. 14;
FIG. 16 is a chart showing line quality judgment data with respect to a line state.
FIG. 17 is a chart showing a reception state for each transmission rate for each line quality determination data.
FIG. 18 is another example of a basic flowchart of the image information maximum allowable transmission rate determination protocol on the receiving side in the facsimile apparatus shown in FIG. 1;
19 is a sequence chart for determining a transmission rate corresponding to the flowchart of FIG.
20 is an example of a basic flowchart of a transmission-side image information maximum allowable transmission rate determination protocol in the facsimile apparatus shown in FIG. 1;
FIG. 21 is a detailed flowchart of polarity inversion / CED check in the flowchart of FIG. 20;
FIG. 22 is a detailed flowchart of preamble check in the flowchart of FIG. 20;
FIG. 23 is another example of a basic flowchart of an image information maximum allowable transmission rate determination protocol on the transmission side in the facsimile apparatus shown in FIG. 1;
FIG. 24 is still another example of a basic flowchart of the image information maximum allowable transmission rate determination protocol on the receiving side in the facsimile apparatus shown in FIG. 1;
[Explanation of symbols]
1 CPU
2 RAM
3 Operation display device
4 Reader
5 Printing device
6 Image processing device
7 Image storage device
8 System controller
9 Communication control unit 1
10 Communication control unit 21
11 Digital network controller
12 Modem
13 Analog network controller
14 System bus
15 Line switching control device

Claims (3)

In a communication apparatus having a transmission / reception means for transmitting / receiving a facsimile signal between a transmission side apparatus and a reception side apparatus via a public line,
The receiving side device
A table indicating the reception state for each line state corresponding to a plurality of transmission rates is obtained in advance, and the line state is determined based on reception of an NSS (non-standard function setting) signal at a specific transmission rate by the transmission / reception means. A transmission rate determining means for determining a maximum allowable transmission rate of transmission / reception by the transmission / reception means by referring to the table based on the line state that is made;
Control means for setting information on the maximum allowable transmission speed determined by the transmission speed determination means to an NSF (non-standard function identification) signal and transmitting the NSF (non-standard function identification) signal by the transmission / reception means. A communication device characterized by the above. The transmission rate determining means is
  Line quality determination data storage means for collecting and storing in advance line quality determination data for determining a line state for each of a plurality of transmission rates;
  Channel quality determination data extracting means for extracting channel quality determination data in the process of receiving an NSS (non-standard function setting) signal of a specific transmission rate by the transmission / reception means;
  Further comprising
  Based on the line quality determination data extracted by the line quality determination data extraction means, the line quality determination data storage means is referred to determine the line state.
  The communication apparatus according to claim 1. The transmitting device is:
  Control means for setting a transmission rate based on information on the maximum allowable transmission rate included in the NSF (non-standard function identification) signal received by the transmission / reception unit
The communication apparatus according to claim 1, further comprising:

Images