JP2001157013A - Image communications equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image communications equipment which can prevent sharp degradation of transmission rate and can reduce the time and labor required for communication. SOLUTION: This image communications equipment, which can be connected to an ISDN being a digital line network and a PSTN being a public analog line network, is provided with a modem for making an image communication even when the image communications equipment is connected to the ISDN or the PSTN and a transmission level control means for changing the transmission level of the modem in accordance with the modem being used for the ISDN or connected to the PSTN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image communication apparatus such as a facsimile apparatus, and its own machine or a partner machine is an ISDN.
The present invention relates to an image communication apparatus for setting the transmission level of its own modem signal when it is connected to an image communication apparatus.

[0002]

2. Description of the Related Art Conventionally, in a facsimile apparatus connected to an ISDN, which transmits an analog signal such as G3, quantization noise when the analog signal is converted to PCM is not taken into consideration. That is, the input level to the PCM encoder, that is, the transmission level of the modem is not set.

[0003] In addition, when the other party is a facsimile apparatus for an analog PSTN line connected to ISDN via a TA (terminal adapter) and a DSU (line terminating device), and when the TA is passed through the TA. TA in
The transmission level of the modem is not determined in consideration of the amount of attenuation of the modem.

[0004]

In the above-mentioned conventional example, the G3 modem, particularly, the ITU-ROM, whose level fluctuates greatly, is used.
T V. In the modem of Recommendation 34, a transmission level that is out of the dynamic range of the PCM codec may be selected.

[0005] In this case, there is a problem that a transmission error increases and a transmission rate drops significantly.

Further, when the other party is connected to the ISDN line via the TA and the DSU, the level of the modem signal is significantly reduced at the modem input section of the other party due to the effect of the attenuation at the TA. In some cases, the S / N ratio of the modem input signal with respect to the noise in the device of the partner machine or the noise on the runway is degraded, the transmission error is increased, and the transmission rate is greatly reduced.

[0007] If the transmission error of the modem increases, the communication is not performed normally, and even if the communication is performed, the transmission rate is reduced. Therefore, the communication time is increased, and the time and energy required for the communication are increased. I need. For this reason, there is a problem that the resource saving and the energy saving are greatly affected.

[0008] Further, since the communication time becomes longer, there is a problem that the communication cost increases and the disadvantage to the user is great.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image communication apparatus capable of preventing a large decrease in transmission rate and reducing the time and energy required for communication.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a digital network ISDN and a public analog network PSTN.
And a modem that performs image communication regardless of whether the image communication device is connected to the ISDN or the PSTN, and a case where the modem is used for the ISDN. And a transmission level control means for changing a transmission level of the modem when the modem is connected to the PSTN.

[0011]

FIG. 5 is a block diagram showing a communication circuit 100 including a modem in a facsimile apparatus according to one embodiment of the present invention.

In the communication circuit 100, a CPU 1 for performing data conversion such as JBIG encoding and decoding, and an SRAM
2, CGROM 3, bus 4, and DUAL PORT RA for exchanging data between buses 4 and 11 side.
M5 and a CPU 6 for controlling the entire communication circuit.

The communication circuit 100 includes a peripheral IC 7 that supports the CPU 6 and controls the communication circuit, and a ROM 8.
And a DRAM 9 for temporarily storing image information and the like, and a communication circuit 1
A communication IC 10 for communicating with parts other than 00, a CPU 6
And the like, a DTMF receiver 12 for detecting a DTMF signal from a line, and an SCA 13 which is a circuit for performing data format conversion and the like by the HDLC means 131 and the like.

Further, the communication circuit 100 includes HDLC means 131 included in the SCA 13 for converting data into HDLC format or extracting only a data portion from data in HDLC format, and a switch circuit SW1. , Modem MODEM1 and modem MO
HDLC means 15 included in the DEM 1 for converting data to HDLC format or conversely extracting only the data portion from HDLC format data
1, a switch circuit SW2, and a PCM codec COD
It has an EC1 and a switch circuit SW3.

The communication circuit 100 is a digital service unit that interfaces with the ISDN.
A network controller NCU1 between the SU19 and the PSTN, and a PCM used for so-called on-hook dialing for checking a voice signal from a partner in an on-hook state when making a call.
CODE CODEC 21 which is a CODEC, a modem MODEM2, and data included in the modem MODEM2.
HDLC means 221 for extracting only the data portion from the data in the C format, and a switch circuit SW4
, PCM CODEC 24 and a telephone, etc.
SLIC25 having the same function as the exchange, PCM
CODEC 26 and network control circuit NC connected to PSTN
U2.

In FIG. 5, a portion indicated by a broken line is a detachable portion, and the portion to be connected is changed depending on whether the line to be connected is PSTN, ISDN, or both. Things.

FIG. 6 is a block diagram showing the facsimile main body 300 to which the communication circuit section 100 is connected.

The facsimile main unit 300 controls a facsimile main unit 301, a reading unit 302 for reading image information for transmission or copying, a recording unit 303 for printing or copying a received image, and the entire main unit. A central control unit 304, a communication circuit unit, and the IEEE 12
A communication IC 305 that communicates with the Vicentronics interface defined by 84, an operation panel 306 that displays the status of the device to the user, and determines the operation of the device according to the user's instruction, and an image memory that stores received images and the like. And RO for storing a program for controlling the device
A communication circuit 100 includes a memory 307 including a RAM for storing M, a telephone number, and the like.

The communication circuit 100 has a communication IC 10,
The communication IC 10 is a bicentronics interface defined by the IEEE 1284, and is a communication IC that communicates with the main unit.

FIGS. 1, 2, 3 and 4 are flowcharts showing the operation of the communication circuit portion 100 and the facsimile main body 300 of the above embodiment.

FIG. 7 shows the PCM C in the above embodiment.
FIG. 3 is a diagram illustrating a dynamic range of ODEC.

FIGS. 8 to 13 are explanatory diagrams of a pre-communication information notification service such as a number display service (a service for knowing the telephone number of the other party's calling terminal before communication).

FIG. 8 is a diagram showing the connection operation in the above embodiment.

FIG. 9 is a diagram showing the signal format of the information receiving terminal activation signal (CAR) in the above embodiment.

The information and other signals used in the number display service and the like are based on ITU-TV. M according to 23
This is based on the ODEM signal. That is, it is a start-stop synchronous FSK (frequency shift keying),
The transmission speed is 1200 bps, and the FO (characteristic frequency) is 1700 Hz. Fz (frequency of mark = 1) is 1300 Hz. FA (frequency of space = 0) = 2100 Hz, and the transmission level is -14d
Bm to -32 dBm. Character composition is JIS
7 unit code. The maximum transmission block length is 128 bytes. Character parity is even parity. The start bit is one bit of 0. The stop bit is one bit of one.

The check bits are in a cyclical code system (CRC), and the control codes are DLE, SOH, S
TX, ETX, SI, SO.

FIG. 10 is a diagram showing a data format in the above embodiment.

A mark bit is a sequence of ones for 60 ms or more.

DLE is a transmission mode control signal (prepared before the control signal).

The SOH indicates the start of the heading of the information message.

The header is a binary signal indicating the start of the heading of the information message.

STX indicates the start of text and the end of heading.

The service type is a binary signal indicating a pre-communication information notification service.

The message content length is a binary signal indicating the total number of bytes from parameters (1) to (n), 1 to 117 bytes.

ETX indicates the end of the text.

SI indicates that a graphic character for Roman characters is used.

SO indicates that katakana characters for graphic characters are used.

The CRC converts the 16 bits of the operation result to the upper 8 bits.
Bit, lower 8 bits.

The parameter types include the outgoing telephone number, the outgoing telephone number extended information, the reason for not transmitting the outgoing telephone number, the called number information, the extended information of the called number information, the transfer source telephone number, the transfer source telephone number extended information, and the name of the transmitting company. (Name) information, originating company name (Name) non-notification reason, public telephone information, etc.

The information content length indicates the content length of each piece of information.

The information content may be a fixed number indicating the information content or a JIS 7 unit code for Roman characters or a JIS 7 unit code for katakana, which may represent a character or a number.

FIGS. 11 to 13 show the above embodiment.
FIG. 3 is a diagram illustrating a transmission format of information and the like.

FIG. 11 is a diagram showing the first mark bit and the DLE part of the transmission signal in the above embodiment.

FIG. 12 shows the SOH, header, DLE, STX, information, DLE, ET that follow in the above embodiment.
FIG. 7 is a diagram illustrating X and other control signal portions.

FIG. 13 is a diagram showing a CRC part in the above embodiment.

FIG. 14 to FIG.
It is explanatory drawing of SDN.

FIG. 14 is a diagram showing an image of an ISDN user and an inter-network protocol.

The ISDN adopts an out-band system in which number information and the like are transferred on a channel (D channel) different from a channel (B channel or H channel) for transmitting telephone voice and the like.

FIG. 15 shows the PSTN in the above embodiment.
FIG. 1 is a diagram showing a state in which a facsimile machine for ISDN and a facsimile machine for ISDN are connected to ISDN.

Here, DSU is NT, and an ISDN terminal directly connected to TE like G4 facsimile is sometimes called TE.

The signal on the ISDN line is 192 Kbp
s signal. This is 250 μS (1/40)
00), two 16 bits included in each 48-bit frame.
B-channel signal of 4 bits, D-channel signal of 4 bits, FA and FB bits for frame synchronization, E (echo) bit for controlling competition, and L bit for DC balance for maintaining electric balance on the line And so on.

FIG. 16 is a diagram showing transmission codes on a line in the above embodiment.

This transmission code is 100% AMI (Alternate
ate Mark Inversion).

0 is expressed by + or = level, and 1 is no signal. Adjacent 0s are those whose polarity is inverted.

FIG. 17 is a diagram for explaining the ISDN protocol.

In FIG. 17, it is assumed that an intermediate system such as an exchange has only a function up to layer 3.

ISDN is based on OSI (Open System Interc
onnection (open system interconnection) as a reference model.

The protocol is a communication protocol for exchanging information between layers.

An access point receiving a service from a lower layer is defined as a service access point (SAP: Service Acquisition).
The information exchanged between layers is called a primitive and a parameter associated with the primitive. There are four types of primitives: requests and responses from upper layers, and instructions and confirmations from lower layers.

A connection is a connection relationship between layers that communicate with each other.
It is provided as a communication path connecting P to one another.

The OSI reference model is composed of seven layers.

Layer 1 is a physical layer, which provides a function of transmitting a “bit string” via a physical medium. The physical condition, electrical condition, mechanical condition, and the like necessary for bit transmission are provided. Has been established.

Layer 2 is a data link layer, which detects a bit error occurring on a transmission path between adjacent communicating systems and recovers the bit error so that the other system can communicate with the other system.
Data block composed of bit strings (frame)
Is a layer that guarantees that data is transferred reliably.

Layer 3 is a network layer, which uses various communication networks such as a data communication network and a telephone network, and has a relay and routing function for establishing a communication path with a terminal system as a communication partner. Manage and guarantee data transmission between end-end systems. In this case, a communication path is set which realizes the throughput and transmission delay required by the upper transport layer with the optimum performance.

Layer 4 is a transport layer that guarantees reliable data transfer between processes that are actually communicating in the final system at both ends of the communication network.

Layer 5 is a session layer. In communication between processes, information having a predetermined meaning is usually transferred while taking a period with each other. The layer 5 manages how to send information required by these processes, and manages synchronization and resynchronization between processes (collectively referred to as dialog management).

Layer 6 is a presentation layer.

Generally, different processes handle different data structures. Therefore, in the communication between processes, it is necessary to transfer the data in a common data structure that can be transmitted and received by both processes. For this purpose, the layer 6 determines the data structure (syntax) to be transferred between the processes, and performs conversion between a data structure unique to each process and a common data structure necessary for the transfer as necessary.

The layer 7 is an application layer.
The part of the process that communicates with the partner process
In the I environment, manage communication general functions according to various business contents.

FIGS. 18 and 19 show the above embodiment.
It is a figure showing a situation of starting of ISDN.

FIG. 18 shows an example in which the ISDN
FIG. 9 is a diagram showing a case in which is activated (activated) from a TE.

FIG. 19 shows an example in which the ISDN
Is a diagram showing a case in which is started from NT.

As shown in the figure, the IN between TE and NT
An electric signal of a specific bit pattern called FO (info) is exchanged.

The stop (activation) is normally performed only from the NT, and the transmission is stopped immediately by setting the transmission signal to a no signal (INFO0).

In the case where TE has come off, for example, NT is set to INF.
O0 is accepted, but it stops after confirming that the state continues for a while.

Layer 2 of ISDN is based on LAP (Link Acc
ess Procedure) -D.

FIG. 20 shows the LAP-D in the above embodiment.
FIG. 3 is a diagram showing a format of a frame.

This is basically based on HDLC (High-Level D
Ata Link Procedure).

The example shown in FIG. 20 includes a start flag, an address section, a control section, an information section (I field), a frame check sequence (FCS), and an end flag.

On the other hand, DISC (Disconnect: disconnect instruction)
In a frame or the like, the I field is not included.

FIG. 21 is a diagram showing the types of frames in the above embodiment.

FIG. 22 is a diagram showing the structure of a layer 3 message in the above embodiment.

Layer 3 has a protocol identifier, a call number, and a message type code as common parts, followed by an essential information element and an additional information element as individual parts.

FIG. 23 is a diagram showing the ISDN in the above embodiment.
FIG. 2 is an explanatory diagram of a protocol of G3 FAX communicating via the Internet.

SABME is an extended unbalanced synchronous mode setting signal. This signal is transmitted first when layer 2 is set. Here, layer 2 is a data link layer, commonly called LAP-D (Link Access Procedure on D).
-channel: link access procedure for D channel). It has the function of overcoming transmission errors and transferring information between the user and the network with high reliability in units of bit strings called frames.

UA (Unnumbered Acknowledge) is an unnumbered acknowledgment signal, and is a response message to SABME and DISC. If the network can be linked, U
Responds with A. If link setup is not possible, DM
(Disconnect Mode) Responds with a signal.

One frame for information transfer is a frame used for transferring layer 3 information in the multi-frame mode, and is used only as a command. The control unit includes a transmission frame sequence number N (R) indicating the number of a frame to be transmitted by itself, and a reception frame sequence number N (R) used for confirming reception of an I frame from the other party.

Layer 3 is a network layer. On the logical link for signal transfer set on the D channel,
A call control message is sent out to perform call control from the beginning to the end of each communication.

The UI (Unnumbered Information) is a frame used for control such as link setting and disconnection, and is used for information transfer in the non-confirmation type information transfer mode.

SETUP is a call setting signal, and the calling side transmits first after setting layer 2 when setting up a call. (I (SETUP)) On the called side, this signal is the first signal received when a call is set up. (UI (SE
TUP)) Thereby, telephone number information, communication terminal attributes, and the like are set.

I (CALLPRO: CALL PROCeeding)
Is a call setting acceptance signal, and the SETUP of the calling side is I
This is an optional message meaning that the message has been accepted by the SDN.

Thus, the fact that the process for call setting is in progress is notified.

I (CONN: CONNect) is a response signal, which is received on the calling side when the partner terminal responds. The called side transmits the SETUP when it can respond to the received SETUP.

I (CONNACK = CONNect ACKnowledg
e) is a response confirmation signal, which is a confirmation signal for I (CONN).

The calling side transmits to the received CONN. On the called side, ISD is sent to the transmitted CONN.
N sends.

I (DISC) is a disconnection signal. Sent when layer 3 is released.

I (REL) is an open signal. Sent when layer 3 is released or when DISC is received.

I (RELCOMP) is an open completion signal. Sent when REL is received. RE sent
ISDN is transmitted to L.

DISC is a disconnection signal. Sent when layer 2 is released.

From CNG to DCN, ITU-T
T. This is a signal defined by 30.

Each analog signal is converted into a digital signal to produce an ISD
This is sent to the other party via N.

When transmitting a modem signal to the ISDN, the above transmission level is selected in a dynamic range which is a portion of the PCM codec where the SN of the input level to the SN ratio is high and the influence of quantization noise is low. .

When the connection is made to the PSTN, FIG.
When the partner device is connected to the ISDN via the TA using the pre-communication information notification service shown in FIG. 13, it detects this by the pre-communication information and optimizes the transmission level.

Further, when connected to ISDN, as shown in FIG. 14 to FIG. 23, information (I frame) from the ISDN side indicates that the other party is connected to ISDN via TA. , Detect it and optimize the transmission level.

More specifically, the transmission level of the training FAX message shown in FIG. 23 is optimized.

That is, the above embodiment is directed to an image communication apparatus which can be connected to both an ISDN which is a digital network and a PSTN which is a public analog network, wherein the image communication apparatus is connected to either the ISDN or the PSTN. A modem for performing image communication even when connected, and transmission level control means for changing a transmission level of the modem depending on whether the modem is used for the ISDN or when the modem is connected to the PSTN. It is an example of an image communication device having the following.

In the above-described embodiment, the image communication apparatus connected to the ISDN via the PSTN or the terminal adapter and the line terminator is connected to the PSTN and to the image communication apparatus connected to the ISDN. This is an example of an image communication apparatus having transmission level control means for changing the transmission level of a modem.

Further, in the above embodiment, the detecting means for detecting whether the receiving image communication apparatus is connected to the ISDN line or the PSTN via the terminal adapter and the line terminating device, This is an example of an image communication apparatus having transmission level control means for changing a transmission level of a modem when the reception image communication apparatus is connected to the ISDN line and when it is connected to the PSTN.

[0109]

According to the present invention, it is possible to prevent a significant reduction in the transmission rate, and to reduce the time and energy required for communication.

[Brief description of the drawings]

FIG. 1 shows a communication circuit portion 100 according to an embodiment of the present invention;
6 is a flowchart showing the operation of the facsimile main body side 300.

FIG. 2 is a flowchart showing an operation of the communication circuit portion 100 and the facsimile main body 300 according to the embodiment.

FIG. 3 is a flowchart showing an operation of the communication circuit portion 100 and the facsimile main body 300 according to the embodiment.

FIG. 4 is a flowchart showing operations of the communication circuit portion 100 and the facsimile main body 300 according to the embodiment.

FIG. 5 is a block diagram showing a communication circuit 100 including a modem in the facsimile apparatus according to one embodiment of the present invention.

FIG. 6 is a block diagram showing a facsimile main body side 300 to which the communication circuit section 100 is connected.

FIG. 7 is a diagram for explaining a dynamic range of a PCM codec in the embodiment.

FIG. 8 is a diagram showing a connection operation in the embodiment.

FIG. 9 is a diagram showing a signal format of an information receiving terminal activation signal (CAR) in the embodiment.

FIG. 10 is a diagram showing a data format in the embodiment.

FIG. 11 is a diagram showing a first mark bit and a DLE part of a transmission signal in the embodiment.

FIG. 12 is a diagram illustrating the following SOH, header, DLE, STX, information, DLE, ETX, and other control signal portions in the embodiment.

FIG. 13 is a diagram showing a CRC part in the embodiment.

FIG. 14 is a diagram showing an image of an ISDN user and an inter-network protocol.

FIG. 15 is a block diagram showing a configuration in which the facsimile apparatus for PSTN and the facsimile apparatus for ISDN are ISDs in the embodiment.
FIG. 7 is a diagram illustrating a state where the connection is made to an N.

FIG. 16 is a diagram illustrating transmission codes on a line in the embodiment.

FIG. 17 is a diagram illustrating an ISDN protocol.

FIG. 18 is a diagram illustrating a case where ISDN is activated (activated) from a TE in the embodiment.

FIG. 19 is a diagram showing a case where ISDN is started from NT in the above embodiment.

FIG. 20 is a diagram showing a format of a LAP-D frame in the embodiment.

FIG. 21 is a diagram showing types of frames in the embodiment.

FIG. 22 is a diagram showing a configuration of a layer 3 message in the embodiment.

FIG. 23 is an explanatory diagram of a G3 FAX protocol for communicating via ISDN in the above embodiment.

[Explanation of symbols]

 100 communication circuit, 300 facsimile main body, 1, 6 CPU, 2 SRAM, 3 CGROM, 4, 11 bus, 7 peripheral IC, 8 ROM, 12 DTMF receiver, 13 SCA, 131 Reference numeral 151: HDLC means, SW1, SW2, SW2: switch circuit, 100: communication circuit part, 300: facsimile main body side, 301: facsimile main body part, 302: reading section, 303: recording section.

Continued on front page F-term (reference) 5C062 AA30 AA34 AB42 AC21 AC40 AE14 AF03 5C075 AB03 AB08 CB03 CD07 CD25 FF04 FF05 5K030 HB02 HC02 HC05 JA03 JA08 JA09 JT04 KA19 LE17 5K101 KK01 LL01 LL03 MM05 NN12 CC06 NN06 CC06

Claims (9)

[Claims] 1. An image communication apparatus connectable to both an ISDN which is a digital network and a PSTN which is a public analog network, regardless of whether the image communication apparatus is connected to either the ISDN or the PSTN. A modem for performing image communication; and transmission level control means for changing a transmission level of the modem when the modem is used for the ISDN and when the modem is connected to the PSTN. An image communication device characterized by the above-mentioned. 2. The transmission level of the modem when the image communication apparatus is connected to the ISDN according to claim 1, wherein the transmission level of the modem is determined by the S / M due to quantization noise of a PCM CODEC provided on the output side of the modem. An image communication apparatus characterized by a transmission level at which the influence of the N ratio is reduced. 3. An image communication apparatus connected to an ISDN via a PSTN or a terminal adapter and a line terminator, wherein a modem is connected to the PSTN and a modem is connected to the ISDN. An image communication apparatus comprising transmission level control means for changing a transmission level of a video signal. 4. A detecting means for detecting whether the other party's receiving image communication device is connected to the ISDN line or the PSTN via a terminal adapter and a line terminating device; and , The above ISDN
An image communication apparatus, comprising: transmission level control means for changing a transmission level of a modem when connected to a line and when connected to the PSTN. 5. The information processing apparatus according to claim 4, wherein the detecting means is configured to receive an IT signal from the image receiving apparatus.
U-T T. 30. An image communication apparatus, comprising: means for detecting based on a response signal including a DIS signal and an NSF signal. 6. The image communication apparatus according to claim 4, wherein said detecting means is means for detecting based on information obtained by a pre-communication information notification service. 7. The image communication apparatus according to claim 4, wherein said detecting means is a means connected to an ISDN line and detecting based on information obtained from the ISDN side. 8. The communication system according to claim 4, wherein the other party's reception image communication device is connected to an ISDN line via a terminal adapter and a line termination device.
The information as to whether or not the mobile phone is connected to the PSTN is stored along with the telephone number of the other image communication apparatus stored in the memory, and the transmission level is changed based on the stored information. Image communication device. 9. The image communication device according to claim 1, wherein the image communication device is a facsimile device.