JP5328624B2 - Image communication apparatus and program for controlling image communication apparatus - Google Patents

Description

  The present invention relates to data communication, and relates to a communication control procedure when an image communication apparatus performs communication via an IP network.

  In recent years, Internet connection services using ADSL (abbreviation of Asymmetric Digital Subscriber Line) and FTTH (abbreviation of Fiber To The Home) have become widespread in homes and small and medium-sized offices. Along with this, the network configuration has changed from a conventional dedicated line network to an IP network using VPN (Virtual Private Network: technology for creating a dedicated line on the Internet).

  In addition, IP telephones using these IP networks have also become widespread. The IP phone is a call means using a technology (VoIP: Voice over Internet Protocol) that transmits voice as an IP packet. As a result, a voice call can be performed with an inexpensive IP network / router or the like without using expensive equipment such as an exchange. With IP telephones, users with many long-distance calls can significantly reduce communication costs.

  With the development and popularization of these IP networks / IP telephones, the number of facsimile terminals connected to the IP network is increasing in businesses and homes, and facsimile communication via the IP network is increasing (FIG. 1).

  The facsimile communication via the IP network is increasing from the conventional facsimile communication only via the public telephone network (communication path (1) in FIG. 1). The facsimile communication via the IP network has the following forms. First, facsimile communication (communication path (2) in FIG. 1) connected to an ISP (Internet Service Provider) by a VoIP router and via the Internet. Next, facsimile communication (communication path (3) in FIG. 1) is connected to an IP network such as a private company line or VPN by a VoIP router and connected to a public telephone network via a VoIP gateway. Furthermore, communication between facsimiles connected in the IP network (communication path (4) in FIG. 1) and the like, and facsimile communication via the IP network in various connection forms.

  In conventional facsimile communication on the public telephone network, the necessary bandwidth on the transmission path is guaranteed, so that communication failure does not occur much. However, as the number of facsimile communications via the IP network increases with the spread of the IP network, communication failures caused by the IP network are gradually increasing.

  In facsimile communication via an IP network, a facsimile signal is divided into packets as voice signals and transmitted, and the reception side assembles the packets and decodes them into voice signals. In IP networks, there is no guarantee of signal transmission time, so when IP network is congested, voice signal bandwidth is not enough, and line failure due to frequency band loss or packet delay / loss occurs. There is a case.

  These failures are likely to occur in a corporate network with a large amount of data to be communicated, and are concentrated in a time zone where data communication is concentrated.

  The voice signal on the transmitter side is transmitted by analog-to-digital conversion, encoding, packet division, and signal transmission by a VoIP router (or a VoIP gateway between the public network and the IP network) before reaching the receiver side. The Routing relay / transfer is performed by a router in the IP network, and a packet is assembled, decoded, and digital-analog converted by a VoIP router (or VoIP gateway) on the receiver side to restore a voice signal.

  In the IP network, the transmission speed of the transferred packet is not constant, and the transferred packet has a difference (fluctuation) in the arrival timing to the VoIP router on the receiver side due to network congestion or failure in the intermediate IP network. ) Occurs (FIG. 2). If the degree of fluctuation is large or packet loss (packet loss) occurs in the IP network, the VoIP router may not be able to recover the signal waveform sampled on the transmitter side, and the voice signal may be momentarily interrupted. It is played back as it occurs.

  Signal interruptions caused by fluctuations in the IP network and packet loss affect facsimile communication.

  Facsimile communication is a communication method in which procedure signal / image data transfer is repeated while synchronizing between a modem on the transmitter side and a modem on the receiver side. In such a communication method that requires synchronization between the transmitter side and the receiver side, the loss of the communication signal due to a momentary interruption causes the modem to lose synchronization. It becomes difficult to maintain the procedure and continue receiving the image data.

  In communication on an IP network, QoS (Quality of Service) is a technique for reserving a bandwidth for a specific communication or prioritizing a packet to guarantee a certain communication speed for the specific communication. There is. QoS is applied in communications that require real-time performance, such as voice and video conferencing. There are many IP network networks that require QoS in real time for procedure signals and image signals, and that implement this QoS even for facsimile communications that are vulnerable to momentary interruption due to packet loss or the like. If QoS is performed for facsimile communication, bandwidth guarantee and priority control are performed, so that communication failures due to packet delay and loss as described above do not occur.

  When performing QoS for facsimile communication, the VoIP router on the IP network side generally starts QoS upon detection of a CED signal first issued by a receiver or a CNG signal first issued by a transmitter. . Here, the CED signal is also called a called station identification signal for identifying the called station, and is a tone signal of 2100HZ. The CNG signal is a signal indicating that the calling side is a non-voice terminal, and is a 1100 HZ tone signal. Generally, the transmitter side stops the CNG signal when it detects the CED signal on the receiver side. However, if the CNG signal stops too early, the CNG signal cannot be detected when the IP network side uses only the CNG signal as a QoS trigger. As a result, there is a problem in that the IP network side cannot perform QoS control, and an instantaneous interruption or the like occurs in the line and communication ends in error.

  FIG. 17, V.R. 27ter, V.I. The communication error process that occurs when the IP network side cannot detect the CNG signal when facsimile communication is started in any of the 29 modulation modes is shown in chronological order from the state of the transmission / reception signal. FIG. The transmitter side detects the CED signal and stops the CNG signal before the VoIP router can detect the facsimile signal. For this reason, when the IP network side uses only the CNG signal as the QoS trigger, the CNG signal cannot be detected and the QoS control is not performed. As a result, a momentary disconnection or the like may occur on the line, and communication may end in an error.

  JP-A-5-30273 is known as a conventional example of a facsimile apparatus that interrupts / restarts a communication processing procedure. In this patent document, when an incoming call arrives at a facsimile apparatus connected to a telephone, call processing is performed by detecting a DTMF signal from the calling side. It is disclosed that when a facsimile apparatus detects a DTMF signal while sending a procedure signal, the procedure process is interrupted and a call request process is performed on the facsimile apparatus. Further, it is disclosed that the procedure process is resumed after a predetermined time has elapsed when there is no response to the call request.

  However, in this patent document, the calling facsimile apparatus does not control the signal transmission timing in order to operate the QoS function on the IP network side.

JP-A-5-30273

  As described above, when performing facsimile communication via the IP network, a line failure such as a momentary interruption is more likely to occur than in the conventional facsimile communication via the public line network, which often results in a communication error. turn into.

  Accordingly, an object of the present invention is to positively use the QoS function on the IP network side to secure a band for facsimile communication, and to maintain the quality of facsimile communication even in an IP network without guarantee of signal transmission time.

In order to solve the problems and problems described above, the present invention provides:
A determination means for determining whether the image communication apparatus is connected to the IP network; Connected to the IP network by a first detecting means for detecting a signal modulated by the 21 modulation method, a sending means for sending a signal indicating that the calling side is a non-voice terminal in accordance with line supplementation, and the judging means If it is determined that the first detection means has detected V.V. According to detection of a signal modulated by the 21 modulation method, the sending means sends a signal indicating that the calling side is a non-voice terminal again.

Furthermore, the present invention provides
In accordance with line supplementation, determination means for determining whether the image communication apparatus is connected to the IP network, second detection means for detecting a tone signal for identifying the called station from the called image communication apparatus, and , A sending means for sending a signal indicating that the calling side is a non-voice terminal; and when the judging means judges that the calling side is connected to the IP network, the second detecting means According to the detection of the tone signal for identification, the sending means sends a signal indicating that the calling party is a non-voice terminal again.

  According to the present invention, since a facsimile signal can be reliably detected on the IP network side, QoS control can be appropriately performed on the IP network side, and the quality of facsimile communication can be maintained.

The network relationship figure which shows the increase in facsimile communication via an IP network. FIG. 3 is a mechanism diagram showing the occurrence of voice quality degradation in an IP network. V. 27ter, V.I. 29, V.R. The sequence diagram which showed the process in which the line failure generate | occur | produces when transmission is performed by the conventional process in any communication mode of 17 modulation systems, and it complete | finishes an error. It is a block diagram which shows the structure of the communication apparatus concerning Example 1 of this invention. In Example 1 of the present invention, V.I. 27ter, V.I. 29, V.R. The sequence diagram which showed a mode that the line | wire failure in one of the communication modes of 17 modulation systems was avoided. V. The sequence diagram which showed the process which a line failure generate | occur | produces and carries out an error end when transmitting in the communication mode of 34 modulation system. In Example 1 of the present invention, V.I. The sequence diagram which showed a mode that the line | wire failure in the communication mode of 34 modulation system was avoided. The flowchart which shows the transmission process in Example 1 of this invention.

Example 1
Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings based on the embodiments shown in FIGS.

  FIG. 4 is a block diagram showing the configuration of the image communication apparatus according to one embodiment of the present invention.

In FIG.
101: The CPU is a system control unit and controls the entire apparatus.
102: The ROM stores a control program for the CPU.
103: The RAM is composed of SRAM or the like, and is used for storing image data.
104: The image memory is constituted by a DRAM or the like, and is used for storing image data.
105: The resolution conversion processing unit performs resolution conversion control such as milli-inch resolution conversion of raster data.
106: A reading / recording coding / decoding processing unit (reading / recording codec) performs coding / decoding processing of image data handled by the communication apparatus.
107: The clock unit measures an operation interval and the like and is configured by an IC or the like.
108: The modem receives and demodulates the modulated signal from the line, and conversely modulates the signal from the apparatus and sends it to the line. The modem 108 is connected to the V.C. 27ter, V.I. 29, V.R. 17, V. It corresponds to a modulation method such as 34.
109: The line i / f unit is a network control unit configured by an NCU or the like. When the telephone has two connection terminals, each connection terminal has a hook detection circuit in order to detect off-hook / on-hook at each terminal.
110: The telephone is a handset (telephone having no dialer) or an external telephone (such as an answering machine) connected to the telephone line through a line i / f unit (NCU).
111: A VoIP router that connects an IP network and a terminal. The VoIP router connects an IP network and a communication device with an analog port.
112: An IP network such as VPN.
113: The image processing unit performs correction processing on the image data read by the scanner and outputs high-definition image data.
114, 115: A sheet scanner and a book scanner are composed of a CS image sensor, a document transport mechanism, and the like, and optically read a document and convert it into electrical image data. Scan double-sided originals.
116: The operation unit includes a keyboard, a display unit, and the like, and is used by the operator to perform various input operations. Indicates that immediate dialing is possible when the handset is off-hook. When the external telephone is off-hook, it displays that communication is in progress and that communication reservations can be accepted.
117: The line buffer is. This is a line buffer used when image data transfer control is performed.
118: The print buffer is a buffer memory for one page for storing the character code for printing.
119: The printer is a printer such as an LBP that records received images and file data on plain paper, and can perform double-sided recording.

  FIG. 5 is a diagram illustrating V.V. in the embodiment of the present invention. 27ter, V.I. 29, V.R. 17 shows a sequence for avoiding a line failure when performing communication in a modulation mode of a modem having any one of 17 communication speeds. The timing of stopping the CNG signal on the transmission side is switched to the timing of detecting the flag or frame of the DIS signal (digital identification signal) instead of the timing of detecting the conventional CED signal. For this reason, the stop timing of the CNG signal extends to a range where the facsimile signal can be detected on the IP network side. As a result, the IP network can determine that this communication is facsimile communication and perform QoS control, and subsequent communication is normally performed.

  FIG. This is a description of a communication error that occurs when the IP network side cannot detect a CNG signal when facsimile communication is started in the communication mode 34. The transmitter side detects the ANSam signal (a tone signal obtained by amplitude-modulating 2100HZ with 15HZ), thereby obtaining V.V. Eight procedures (V.34 Phase 1) are performed. The ANSam signal is also an example of a called station identification signal for identifying the called station. In FIG. 5, the CNG signal is stopped before the IP network can detect the facsimile signal. For this reason, when the IP network side uses only the CNG signal as the QoS trigger, the CNG signal cannot be detected and the QoS control is not performed. As a result, a momentary disconnection or the like may occur on the line, and communication may end in an error.

  FIG. 7 is a diagram illustrating V.V. in the embodiment of the present invention. FIG. 34 is a sequence diagram showing how a line failure is avoided in 34 communication modes. The transmitting side controls to continue sending CNG signals without sending CM signals even if ANSam sent from the receiving side is detected. For this reason, the receiver side times out ANSam and V. Shift to a low-speed procedure using the 21 modulation method and send a DIS signal. The stop timing of the CNG signal extends to a range where the facsimile signal can be detected on the IP network side. Therefore, the IP network can determine that this communication is facsimile communication and perform QoS control. After this, the transmitter side transmits the V.V. 8 Confirm the capability and send out CI signal. Start 8 procedures and 34 procedures can be performed, and communication is performed normally. Here, the ANSam timeout occurs at the receiver side and V. An example of shifting to a low speed procedure using the 21 modulation method has been described. However, V.V. In such a case, it is necessary to spend time before using the 34 procedure. 34 communication is prohibited. 27ter, V.I. 29, V.R. You may control to perform any one of 17 communication.

  FIG. 8 is a flowchart showing the transmission processing in the embodiment of the present invention. This flowchart is executed by the CPU 101 in accordance with a program stored in the ROM 102.

  When the transmission instruction is given, the CPU 101 instructs the NCU (109) to supplement the line (S1). Subsequently, the destination telephone number is dialed (S2). A T1 timer (60 seconds) for detecting an initial identification signal after dialing is set (S3). Subsequently, a timer value is set in the CNG off timer so that a CNG signal is transmitted after one second (S4).

  From (S5) to (S15), a loop process for sending a CNG signal while detecting a signal is performed. When the CPU 101 detects the timeout (T1 timeout) of the timer for detecting the initial identification of the facsimile (S5), an IP network route flag is set (S6). Here, the reason why the IP network via flag is set is that the cause of the T1 timeout is that the CNG signal could not be detected on the IP network side, and communication could not be established because necessary QoS control was not performed. is there. Thereafter, redial set (S7) is performed to release the line. A busy tone is sent when the other party cannot answer because the other party is busy. When a busy tone is detected (S8), the line is opened by setting redial (S7) without setting the IP network flag. . Here, it is clear that the reason why the communication with the other party is not established is that the IP network via flag is not set not because the QoS control is not performed on the IP network side, but the other party is busy. Because.

  In (S9), an IP network flag for determining whether to perform control for enabling the QoS function of the IP network is confirmed. When the IP network flag is off, the ANSam signal from the called terminal is confirmed in (S10). If the ANSam signal can be detected, V. Eight procedures (V.34 phase 1) are processed and V. 8 Wait for the end of the procedure. As a result of 8 procedures, V. If communication is possible in 34 communication modes (S21) The process proceeds to 34 phase 2 processing. V. As a result of 8 procedures, V. If communication in 34 mode is not possible, the process proceeds to (B). A low speed procedure using the 21 modulation scheme is performed.

  If the ANSam signal cannot be detected in (S10), it is confirmed whether a tone signal indicating a CED signal is detected from the called terminal (S11). If the CED signal can be detected (normal transmission of V.17 or lower), the CNG signal is stopped (S23).

  If the CED signal cannot be detected in (S11), V.D. is detected in order to detect the DIS signal transmitted from the receiver side at an early stage or at least. 21H carrier (carrier frequency of the procedure signal) is detected (S12). Similarly, when the IP network flag is ON in (S9), V. The 21H carrier is detected (S12). V. When the 21H carrier is detected, the timer until the CNG signal is transmitted again for detection of the DIS signal is extended (S22), and the CNG signal is stopped (S23). When the CNG off timer times out (S24), a CNG signal indicating that the calling side is a non-voice terminal is sent again in (S14). As described above, since the transmitter transmits the CNG signal even after detecting the DIS signal, the transmitter can reliably notify the IP network that the facsimile communication is executed. If the DIS signal can be detected (S25), the V.V. The 8 capability bits are confirmed (S26). V. 8 If the ability is not confirmed, V. In order to perform communication of 17 or less, T.17. Move to 30 node A. This causes the transmitter to send a DCS signal and The facsimile communication can be started at 17 or less. V. If 8 abilities can be confirmed, V. Since communication in the 34 mode is possible, the CI signal transmission mode is set (S27). Hereinafter, V. Facsimile communication in 34 mode is executed.

  Since the DIS signal is detected by skipping (S10) and (S11) in the determination of (S9), it can be determined that the QoS function on the IP network side has already been enabled, so the IP network flag is reset (S28). To do.

  A modification of the flowchart described in FIG. 8 will be described below. Hereinafter, some of the West knife variations may be executed in combination with the flowchart of FIG.

  Here, an example has been described in which the IP network via flag is set in (S6) when a T1 timeout occurs in (S5), but the present invention is not limited to this. When the user knows that the transmitter is connected to the IP network, the user may be caused to set the IP network flag via the operation unit 116. In this case, in (S1), the user sets an IP network flag, and in (S8), the CPU 101 can determine that the IP network is passed even if the T1 timeout in S5 does not occur. Similarly, when the other party number starts with 050, the CPU 101 may determine that it is connected to the IP network and set the IP network via flag.

  Further, when the IP network flag is on in (S9), V. Although the example which detects a 21H carrier was demonstrated, it is not restricted to this. (S12) Instead of detecting the 21H carrier, a tone signal indicating a CED signal may be detected as in (S11). However, in this case, the CED signal is detected, and the CNG off timer is extended as in (S22). As a result, the CNG can be sent again, so that the QoS function can be surely activated. However, when the IP network flag is off, if a CED signal is detected in (S11), CNG transmission is stopped without extending the CNG off timer.

  Further, the DIS signal is detected in (S25), and V. is detected in (S26). If it is confirmed that there are 8 capabilities, execute (S27), The example in which facsimile communication is executed in 34 has been described, but is not limited thereto. (S26) Even if it is confirmed that there are 8 capabilities, if the IP network flag is set, V. 8 mode, V. Communication in the 34 mode is prohibited. You may make it transfer to 30 node A. That is, only when the IP network flag is not set, You may make it perform communication in 34 mode. By doing so, it is possible to prevent the pre-procedure from being executed many times and to shorten the communication time.

  Furthermore, as shown in (S22), V. Although the timing for sending the CNG signal is controlled by controlling the CNG off timer after detecting the 21H carrier, the present invention is not limited to this. In order to reliably detect CNG signals on the IP network side, V. The number of transmissions after detecting the 21H carrier may be increased, or control may be performed so as to increase the ON time of the CNG signal. In short, even if an identification signal from the called party is detected, if the CNG signal transmission can be continued at least once without stopping the transmission of the CNG signal immediately, the QoS function is surely performed on the IP network side. Can be done.

  Further, although an example in which a single CPU executes the flowchart of FIG. 8 is described here, the present invention is not limited to this. A plurality of CPUs may be executed in a distributed manner.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

101 CPU
102 ROM
103 RAM
104 Storage memory (image memory)
105 Resolution conversion processing unit 106 Coding decoding processing unit for reading and recording 107 Clock unit 108 Modem 109 NCU (line if unit)
DESCRIPTION OF SYMBOLS 110 Telephone 111 VoIP router 112 IP network 113 Image processing part 114 Sheet scanner 115 Book scanner 116 Operation part 117 Line buffer 118 Print buffer 119 Printer

Claims (13)

Determining means for determining whether the image communication apparatus is connected to the IP network;
The V.V. First detection means for detecting a signal modulated by the 21 modulation method;
Sending means for sending a signal indicating that the calling side is a non-voice terminal according to the line supplement;
When it is determined by the determination means that the connection is made to the IP network, the first detection means determines the V.P. 21. An image communication apparatus according to claim 21, wherein in response to detection of a signal modulated by the 21 modulation method, the sending means sends again a signal indicating that the calling side is a non-voice terminal. Second detection means for detecting a tone signal for identifying a called station from the image communication apparatus on the called side;
When it is not determined by the determining means that the terminal is connected to the IP network, the sending means indicates that the calling side is a non-voice terminal according to the detection of the tone signal by the second detecting means. The image communication apparatus according to claim 1, wherein transmission of the image is stopped. Determining means for determining whether the image communication apparatus is connected to the IP network;
Second detection means for detecting a tone signal for identifying a called station from the image communication apparatus on the called side;
Sending means for sending a signal indicating that the calling side is a non-voice terminal according to the line supplement;
When it is determined by the determining means that it is connected to the IP network, the transmitting means re-sends in response to detection of a tone signal for identifying the called station by the second detecting means. An image communication apparatus for transmitting a signal indicating that a caller is a non-voice terminal.   When it is not determined by the determining means that the terminal is connected to the IP network, the sending means indicates that the calling side is a non-voice terminal according to the detection of the tone signal by the second detecting means. The image communication apparatus according to claim 3, wherein transmission of the image is stopped. A third detecting means for detecting the ANSam signal;
When it is determined by the determining means that it is connected to the IP network, the sending means confirms that the calling side is a non-voice terminal again according to the ANSam signal detected by the third detecting means. 5. The image communication apparatus according to claim 1, wherein a signal to be transmitted is transmitted.   A fourth detection unit for detecting a digital identification signal from the image communication apparatus on the called side; and when the determination unit determines that it is connected to the IP network, the fourth detection unit In accordance with the detection of the digital identification signal from the called image communication apparatus, V. The image communication apparatus according to claim 5, wherein eight procedures are executed.   When it is determined by the determining means that it is not connected to the IP network, the sending means indicates that the calling side is a non-voice terminal according to the ANSam signal being detected by the third detecting means. Stop sending signals, The image communication apparatus according to claim 5, wherein eight procedures are executed.   When the determination means determines that the image communication apparatus is connected to the IP network, 5. The image communication apparatus according to claim 1, wherein execution of eight procedures is prohibited.   9. The determination unit according to claim 1, wherein the determination unit determines that a connection to the IP network is established because communication with the image communication device on the called side is not established. Image communication device. It further has setting means for setting whether or not it is connected to the IP network,
9. The determination unit according to claim 1, wherein the determination unit determines that the connection unit is connected to the IP network when the setting unit is set to be connected to the IP network. Image communication device.   The apparatus further comprises fifth detecting means for detecting whether the destination number is a number starting with 050, and the determining means is configured to detect that the destination number is a number starting with 050 by the fifth detecting means. The image communication apparatus according to claim 1, wherein the image communication apparatus is determined to be connected to an IP network. A determination step of determining whether the image communication means is connected to the IP network;
The V.V. A first detection step of detecting a signal modulated by the 21 modulation method;
A sending step of sending a signal indicating that the calling party is a non-voice terminal according to the line supplement;
If it is determined by the determination step that the connection to the IP network is established, V.V. A program for controlling an image communication apparatus, characterized in that, in response to detection of a signal modulated by the 21 modulation method, the sending means sends a signal indicating that the calling side is a non-voice terminal again. . A determination step of determining whether the image communication means is connected to the IP network;
A second detection step of detecting a tone signal for identifying a called station from the called image communication device;
A sending step of sending a signal indicating that the calling party is a non-voice terminal according to the line supplement;
When it is determined by the determination step that it is connected to the IP network, the transmission step is started again according to the detection of the tone signal for identifying the called station by the second detection step. A program for controlling an image communication apparatus, characterized in that a signal indicating that a caller is a non-voice terminal is transmitted.

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