KR20000000913A - G3 facsimile data processing method in cdma pcs/dcn - Google Patents

Abstract

PURPOSE: A G3 facsimile data processing method in CDMA PCS/DCN is provided to communicate with public network member by mounting member's modem in a moving data communication controller. CONSTITUTION: The G3 facsimile data processing method in CDMA PCS/DCN comprises: a step identifying the spare source of a line data processor(25) and setting a facsimile by a moving data communication controller(20) according to the G3 fax data communication request through a moving terminal; a step sending pre-message informing the ability of the requested G3 fax data communication through the moving terminal according to the completion of the G3 fax setting; a step transmitting the G3 fax data through the moving terminal according to the pre-message; a step identifying whether or not the transmitted G3 fax data are successfully sent; and a step releasing the fax after the G3 fax data are transmitted.

Description

Method of processing G3 (X3) fax data in CDM PS / DCC

The present invention relates to a G3 fax data communication service in a CDMA Personal Communication Service / Digital Cellular Network. In particular, a modem that can be used by a mobile subscriber is installed in a mobile data communication control device. The present invention relates to a G3 fax data processing method for enabling G3 fax data communication with a public network subscriber by using the same.

Recently, mobile communication service providers have been providing wireless data communication services in an effort to overcome extremely limited communication services due to wireless environments and to satisfy the needs of communication subscribers.

The present invention aims to propose a more advanced method for processing G3 fax data for a fax data communication that has recently been proposed.

First, G3 (Group 3) refers to a third group fax communication, and refers to a fax communication that transmits an A4 version document in about one minute by a digital method using a public network. The G3 scans a document, converts it into a digital signal, applies a process for suppressing redundancy to the converted signal, and compresses and transmits the number of bits to about 1/10.

Using the A4 version as a standard, 3.85 lines / mm (Fine Mode is 7.7 lines / mm), and transmit at the number of pixels per scan line length of 1,728 / 215mm. Modified Huffman (MH) and Modified Read (MR) methods are used.

In addition, procedures for automatic setup of a call through a public network are standardized in ITU-T, and have transmission speeds of 2400, 4800 bps (standard) and 9600 bps (optional).

At present, most of the international document transmission is performed by such G3 fax communication.

1 is a block diagram showing the basic configuration of a fax data communication system according to the prior art.

Referring to FIG. 1, a conventional fax data communication system using a mobile communication network includes a first personal computer 1 equipped with a PCMCIA (hereinafter, referred to as PCMCIA) modem card, and A mobile terminal 2 connected to the first personal computer 1, a wireless base station 3 that transmits and receives a wireless signal to and from the mobile terminal 2, and a base control station 4 which is in charge of controlling the wireless base station 3; ), A mobile telecommunication switching center 5 which performs connection processing for exchanging fax data between mobile subscribers, and a G3 fax telephone 6 or PCMCIA modem card for exchanging fax data over the public network. And a second personal computer 7.

The fax data communication system according to the related art configured as described above has a fax call for fax data communication through a fax emulator (not shown) of a first personal computer 1 equipped with a PCMCIA modem card. When attempted, the mobile terminal 2 connected to the first personal computer 1 transmits a radio signal according to the attempted fax call to the radio base station 3.

The radio base station 3 receives radio signals for outgoing fax data communication, whereby the base control station 4 and the mobile switching center 5 are connected to a public network G3 fax telephone 6 or a second personal computer ( The data communication path with 7) is established.

At this time, the base station 4 and the mobile telecommunication switching center 5 provide the fax emulator (not shown) of the first personal computer 1 and the PCMCIA modem card to communicate the fax data through the mobile terminal 2. You will be notified that the setup is complete.

After the setting of the communication path is completed, the fax emulator (not shown) and the PCMCIA modem card of the first personal computer 1 are respectively referred to as Data Terminal Equipment (hereinafter, abbreviated as DTE) and data line termination (Data Circuit-). terminating equipment (hereinafter abbreviated as DCE).

Error detection and data flow control must be performed between the DTE and DCE for accurate fax data transmission. Through the error detection and data flow control for fax data transmission, the first personal computer 1 is connected to a second personal computer ( 7) or fax data to the G3 fax telephone (6).

The information exchange between the DTE and the DCE is divided into Class 1 and Class 2 according to the information exchange method. In general, the G3 FAX 6 uses a Class 1 information exchange method. use.

As described above, the fax data communication service using the conventional fax data communication system requires that a mobile subscriber always have a modem installed in his or her personal computer or a separate G3 fax telephone to transmit fax data. There was a problem.

In addition, there is a need for a study on a more specific method for processing G3 fax data for a G3 fax data communication service between a mobile subscriber and a public subscriber in a future CDMA mobile communication network.

The present invention has been made to solve the above problems, to install a modem in a mobile data communication control device for a G3 fax data communication service connected to the existing CDMA PCS / DCN communication system, such mobile data communication control It is an object of the present invention to provide a more advanced method for processing G3 fax data for G3 fax data communication between a mobile subscriber and a public subscriber in a CDMA mobile communication network.

A feature of the G3 fax data processing method in the CDMA PCS / DCN according to the present invention for achieving the above object is that the mobile data communication control device is an idle resource of the line data processing unit in response to a request for G3 fax data communication through the mobile terminal. Setting a fax call by confirming a message, and transmitting a connection message (Pre-Message) indicating that the requested G3 fax data communication is possible through the mobile terminal as the setting of the G3 fax call is completed, and the access message is delivered. And transmitting the G3 fax data through the mobile terminal, confirming whether the transmitted G3 fax data has been successfully transmitted, and releasing the fax call as the transmission of the G3 fax data is completed. It is done.

Preferably, before the G3 fax data transmission step, a specific data pattern is transmitted to prevent fax call disconnection due to a delay time between the mobile terminal and the modem.

Further, in the step of transmitting the G3 fax data as the access message is transmitted, when the G3 fax data is lost during transmission between the mobile terminal and the mobile data communication control device, requesting retransmission of the lost G3 fax data is requested. And periodically transmitting any data to keep the established fax call while waiting for the requested G3 fax data. Here, any data for continuing to hold the fax call is transmitted two or three times periodically for five seconds.

In addition, in the step of transmitting the G3 fax data as the access message is transmitted, a time for retransmission of error data generated due to a bad wireless environment existing between the mobile terminal and the mobile data communication control device (Retransmission Time Out) By reducing the time delay due to subsequent retransmissions, the fixed retransmission time is fixed such that no retransmission is performed for the error data more than three times.

Finally, in the step of transmitting the G3 fax data, the transmission speed for the G3 fax data transmitted between the mobile terminal and the mobile data communication control device maintains the initial speed regardless of the public network transmission state, and the transmitted G3 In the step of confirming that the fax data has been successfully delivered, the fax-only emulator provided in the personal computer transmits an 'EOP' indicating the end of the transmission G3 fax data, and then confirms the completion of transmission of the G3 fax data from the mobile data communication control device. The waiting time for a message is set to 30 seconds or more.

1 is a block diagram showing the basic configuration of a fax data communication system according to the prior art.

2 is a block diagram showing the basic configuration of a G3 fax data communication system according to the present invention;

Figure 3 is a block diagram showing the configuration of a mobile data communication control device in a G3 fax data communication system according to the present invention.

4 is a block diagram showing the configuration of a line data processing unit in the mobile data communication control apparatus according to the present invention;

5 is a block diagram showing the configuration of a virtual data terminal (DTE) and a virtual data line termination (DCE) for a G3 fax data communication service according to the present invention.

6 is a diagram illustrating a control process for establishing a fax call between a virtual data terminal (DTE) and a virtual data line termination (DCE) according to the present invention.

7 illustrates a control process for transmitting G3 fax data after completion of setting up a fax call between a virtual data terminal (DTE) and a virtual data line termination (DCE) according to the present invention.

a) shows the basic control procedure for transmitting each page of G3 fax data.

b) is a diagram illustrating a control process for a case where G3 fax data is lost on a virtual data terminal (DTE).

* Description of the symbols for the main parts of the drawings *

20: mobile data communication control device 21: mobile data path connection

22: public network data path connection 24: main processor

25: line data processing unit

Hereinafter, a preferred embodiment of a G3 fax data processing method in a CDMA PCS / DCN according to the present invention will be described with reference to the accompanying drawings.

First, service options used in the wireless data communication service include SO4, SO5, SO7, SO12, SO13, and SO15. Here, SO4 and SO12 indicate that the data used is asynchronous data, SO5 and SO13 indicate that the data used is G3 fax data, and SO7 and SO15 indicate that the data used is common point-to-point packet data Will be displayed.

Among these service options, SO4, SO5, and SO7 belong to Rate Set 1, which provides 9.6 kbps, and SO12, SO13, and SO15, Rate 2, which provides 14.4 kbps. It belongs to Set 2).

The service options used in the G3 fax data communication system according to the present invention are SO5 and SO13, which informs each mobile communication network element that the corresponding fax call is for G3 fax data.

In addition, in the present invention, Class 2 or Class 2.0 is used as a facsimile mode for exchanging information, which is based on the fax specification IS-592. This mode is controlled. Class 2 is a fax mode that is based on IS-592 but some commands can be modified by the fax modem manufacturer. In addition, in the present invention, G3 FAX Class 1 on the mobile subscriber side is not provided.

2 is a block diagram showing the basic configuration of a G3 fax data communication system according to the present invention.

Referring to Figure 2, the configuration of the G3 fax data communication system according to the present invention comprises a mobile data communication control device 20 equipped with a fax modem so that the mobile subscribers can perform G3 fax data communication do. Therefore, the personal computer 10 does not have to be separately provided with a modem for transmitting fax data through the mobile terminal 11.

The G3 fax data communication system configured as described above installs a fax modem in the mobile data communication control device 20 to provide a G3 fax data communication service to a desired mobile communication subscriber.

The first personal computer 10 and the mobile terminal 11 are connected to a serial input / output port (SIO port) according to RS-232E, and the traffic channel setting of the existing mobile communication is established between the mobile terminal 11 and the wireless base station 12. The method is used as it is.

When the mobile subscriber inputs the telephone number of the called party's public network subscriber through the fax-only emulator (not shown) of his first personal computer 10, the previously entered telephone number is transferred to the first mobile terminal 11. It is converted into an outgoing message on the radio and transmitted to the radio base station 12. At this time, the first mobile terminal 11 uses the service option SO5 or SO13 used for the G3 fax data communication service.

When the outgoing message is delivered to the mobile communication switching center 14 via the wireless base station 12, the mobile communication switching center 14 confirms whether the outgoing message is a message requesting a G3 fax data communication service.

When it is determined that the mobile communication subscriber requests G3 fax data communication, the mobile communication switching center 14 connects a fax call with the mobile data communication control device 20.

Accordingly, the mobile communication switching center 14 inputs to the fax-only emulator (not shown) of the first personal computer 10 as the fax call setting for the G3 fax data communication with the mobile data communication control device 20 is completed. Will try to connect to the phone number.

At this time, when the connection with the other party's public network subscriber for G3 fax data communication is completed, the mobile communication subscriber transmits the fax content file to be transmitted through the fax-only emulator (not shown) of the first personal computer 10. After creating a Fax Encoding File with a Scanning Coding Algorithm based on ITU-T T.4, it is possible to transmit a Fax Encoding File through a mobile data path and a public network data path.

As such, the G3 fax data communication system according to FIG. 2 is based on the data service standard in the CDMA PCS / DCN, and the mobile terminals 11 and 18 have a protocol stack, a fax call processing module, and an RLP for the G3 fax data communication service. (Radio Link Protocol) should be added. In addition, the radio base station 12, 19 and the base station 13 are capable of changing the fax data of the RLP (Radio Link Protocol) and Vocoder of the SVM (Selector & Vocoder Module) included in the base stations 12, 19. Should be added.

The mobile communication switching center 14 analyzes the signals transmitted from the base stations 12 and 19 and the base station 13, and changes the path to the mobile data communication control device according to the service options in the mobile terminals 11 and 18. A switching function must be added to make this possible.

Figure 3 is a block diagram showing the configuration of a mobile data communication control device in a G3 fax data communication system according to the present invention.

Referring to FIG. 3, as the mobile communication switching center described with reference to FIG. 2 requires a fax call setup for G3 fax data communication with the mobile data communication control apparatus 20, the mobile data path connecting portion 21 is set to the main. This is reported to the processing unit 24.

Accordingly, the main processor 24 allocates one effective channel for G3 fax data communication, and then checks whether an idle resource is prepared from the line data processor 25 to determine whether an idle modem is prepared. Perform This establishes a mobile data path for G3 fax data communication between the first personal computer (not shown) and the mobile data communication control device 20.

After the mobile data path is established, a link layer and a transport layer for G3 fax data communication between the line data processing unit 25 of the mobile data communication control device 20 and the first personal computer (not shown). A communication protocol stack consisting of a layer, a network layer, and an application interface layer must be constructed.

Further, after the main processing unit 24 receives the confirmation of the idle resource from the line data processing unit 25 in the process of establishing the mobile data path, the main processing unit 24 immediately attempts to establish a communication connection with the public network communication subscriber through the public network data path connection unit 22. do.

When the communication connection with the public network communication subscriber is successfully completed, the main processing unit 24 of the mobile data communication control device 20 enables G3 fax data communication between the first personal computer (not shown) and the line data processing unit 25. Do it.

As shown in FIG. 3, the line data processing unit, as illustrated in FIG. 4, communicates a communication protocol between the data processing main controller 210, the application interface control module 220, and a first personal computer (not shown). According to the configuration of the transport and network layer protocol (230) and the point-to-point protocol (240) to establish and the protocol stack established for the aforementioned G3 fax data communication, G3 fax data communication is performed. It comprises a modem control unit 250 and a modem 260 to perform.

Referring to the circuit data processing unit 200 configured as described above in more detail, when there is an idle resource allocation request for G3 fax data communication from the main processing unit 100, the line data processing unit 200 performs a data processing main control unit 210. And the idle resource occupancy state of the modem 260 through the application interface control module 220 and reporting the previously confirmed result to the main processor 100, thereby the modem 260 of the line data processor 200. Is initialized with default configuration values, which will eventually enable G3 fax data communication over the mobile data path and the public network data path.

5 is a block diagram showing the configuration of a virtual data terminal (DTE) and a virtual data line termination (DCE) for a G3 fax data communication service according to the present invention.

5, in a basic configuration of the G3 fax data communication system according to the present invention described with reference to FIG. 2, the data terminal (DTE) 500 may be a personal computer, a mobile terminal, a wireless base station, and a base station. And all elements other than the modem embedded in the mobile telecommunication switching center and the mobile data communications control device.

In addition, the virtual data line termination (DCE) 600 will include a modem embedded in the mobile data communication control device.

As described above, the virtual data terminal (DTE) 500 of the G3 fax data communication system according to the present invention includes a fax call (delay) of a fax encoding file, which is a subscriber's transmission request data file transmitted from a fax-only emulator of a personal computer. In order to eliminate truncation of the fax call, the transmission delay time of the fax encoded file is compensated.

To this end, during the transmission delay time of the fax encoding file, the virtual data terminal (DTE) sends a specific data pattern, not a transmission request data file of the mobile subscriber, to the modem of the virtual data line termination (DCE), It will keep the call.

6 and 7 illustrate a control process for a G3 fax data communication service between the virtual data terminal (DTE) and the virtual data line termination (DCE) of FIG. 5. To illustrate this, a protocol stack for the G3 fax data communication service is illustrated. Briefly mentioned,

The mobile terminal may be referred to as an application interface layer (hereinafter referred to as AI), a transmission control protocol layer (hereinafter referred to as TCP), and an internet protocol layer (hereinafter referred to as IP). Point-to-point protocol layer (hereinafter referred to as PPP), and a radio link protocol layer (hereinafter referred to as RLP). The mobile data communication control device configures AI, TCP, and IP.

Here, the RLP defined in IS-99 converts a frame transmitted between the mobile terminal and the PPP of the mobile data communication control device according to an interface section Um formed between the mobile terminal and the mobile data communication control device. In the PPP frame transmission, an error processing capability due to a wireless environment is enhanced. This RLP is a protocol established between the mobile terminal and the base station.

PPP almost corresponds to the link layer of the seven layers defined by the Open System Interconnection (OSI), and according to the present invention, the mobile data communication control device (not shown) and the mobile terminal described with reference to FIG. It provides point-to-point communication according to the capability between 710 and performs reliable G3 fax data transmission through HDLC (High level Data Lick Control; hereinafter abbreviated as HDLC) frame.

TCP corresponds to a transport layer among the seven layers defined by the Open System Interconnection (OSI). In the present invention, reliable G3 fax data transmission and flow control of G3 fax data through error detection are provided. In charge. In addition, TCP plays a role of preventing time delay and degradation of system efficiency due to excessive retransmission when a lot of errors occur in a wireless environment.

IP almost corresponds to the network layer of the seven layers defined by the Open System Interconnection (OSI).

6 is a diagram illustrating a control process for establishing a fax call between a virtual data terminal (DTE) and a virtual data line termination (DCE) according to the present invention, and FIG. 7 is a virtual data terminal (DTE) and virtual data according to the present invention. A diagram illustrating a control process for transmitting G3 fax data after completion of setting a fax call between line terminations (DCE), and for a G3 fax data communication service according to the present invention shown in FIGS. 6 and 7. All control processes can be defined as five phases: Phase A, Phase B, Phase C, Phase D, and Phase E.

Referring to FIG. 6, once a file to be transmitted through a fax-only emulator (not shown) of the personal computer 700 is made into a fax encoding file and then transferred to the mobile terminal 710, the mobile terminal 710 may do so. It is found that the request is a fax call (S1).

The mobile terminal 710 transmits an outgoing message for the previously requested fax call to the wireless base station using the service option SO5 or SO13 (S2), and the previously transmitted message is transmitted through the base control station and the mobile communication switching center. It is used as a message for requesting a fax call to the main processor 720 of the communication control device.

When the main processing unit 720 receives the fax call request from the mobile terminal 710, the main processing unit notifies the fax call request by receiving an idle resource for the G3 fax data communication from the line data processing units 730 and 740 (S3). . Accordingly, the line data processing unit 730, 740 generates a line data processing task 730 related to the line data processing modem 740 for G3 fax data communication, and the pre-generated line data processing task 730 is a main processing unit ( In response to the facsimile call request of 720, a line data processing modem 740 having an initial configuration value is assigned.

The generated line data processing task 730 performs protocol negotiation between the mobile terminal and the PPP and TCP / IP layers.

It is based on a protocol stack configured in each network element to provide a G3 fax data communication service. Each protocol layer has been described above.

When the protocol negotiation between the PPP and TCP / IP layers between the line data processing task 730 and the mobile terminal is completed, the mobile terminal 710 receives the AT for G3 fax received from the fax-only emulator (not shown) of the personal computer 700. The command, ATDT, and public network subscriber number are transmitted to the generated line data processing task 730 (S5). Accordingly, the line data processing task 730 transmits an AT command for G3 fax data communication to the line data processing modem 740 allocated above (S6), and transmits the public network subscriber to the main processing unit 720. Pass the phone number (S7).

Thus, the main processor 720 calls the public network subscriber number to the public network data path connection unit, and when the connection with the public network subscriber is made, the circuit data processing task 730 requests a connection to the circuit data processing modem 740. Will be performed.

When the fax call is established through the public network data path, the main processor 720 notifies the line data processing task 730 that the fax call through the public network data path is established, and also makes a request for carry detection (S8). . Accordingly, the line data processing task 730 transmits an AT command to the line data processing modem 740 (S9).

In step S8 and S9, the modem carry is detected from the line data processing modem 740 of the line data processing unit and the modem of the personal computer (not shown) of the G3 fax telephone (not shown) or the public network subscriber, and the line data processing is performed. The line data processing task 730, which has received + FCON, + FDIS; OK from the modem 740, transmits the line data processing modem 740 connection confirmation message to the main processor 720 (S10 and S11). In addition, the line data processing task 730 transmits + FCON, + FDIS; OK to the personal computer 700 to notify the line data processing modem connection confirmation (S12).

Through the steps S1 to S12, the phase 1 of setting a fax call is completed.

When the phase 1 is finished, a process of exchanging parameters for checking the modem performance of the public network subscriber, etc. is performed (S13 and S14). First, the fax-only emulator of the personal computer 700 passes through all network elements and the line data processing modem. Forwards the 'AT + FDT' message to the 740, and the line data processing modem 740 forwards the 'FDCS; CONNECT' message to the fax-only emulator of the personal computer 700, thereby providing a preceding message (Pre). -Message) Phase 2, the delivery phase, ends.

As described above, as Phase 2 ends, it enters Phase 3 which transmits G3 fax encoded data.

FIG. 7 illustrates a control process for transmitting G3 fax data after completion of setting up a Fax call between a virtual data terminal (DTE) and a virtual data line termination (DCE) according to the present invention. FIG. FIG. 7B is a diagram illustrating a basic control procedure for transmitting each page of data, and FIG. 7B is a diagram illustrating a control procedure when G3 fax data is lost on a virtual data terminal (DTE).

Referring to FIG. 7A, first, a process of exchanging parameters for checking modem performance of a subscriber of a public network, which is Phase 2, is performed (S100 and S110).

At this time, the line data processing modem 830 checks the status of the other party's subscriber modem and provides the XON (Ox11) character to the fax-only emulator of the personal computer 800 to start transmission of the G3 fax data (S120). .

The fax-only emulator that receives the XON character transfers the G3 fax encoding data to be transmitted to the line data processing task 820 through the mobile terminal 810 (S140, S150), and the line data processing task 820 again receives G3. The fax encoding data is transmitted to the line data processing modem 830 (S160).

At this time, between the mobile terminal 810 and the line data processing task 830, the G3 fax encoding data is included in the TCP packet and transmitted.

As such, the fax call must be maintained in the process of delivering G3 fax encoded data. However, in order to normally provide the fax encoding data provided from the fax-only emulator of the personal computer 800 to the line data processing modem 830, a large amount of time is initially required, and the fax call is released due to such a large amount of time. To prevent this, perform 'Zero Fill' processing.

The 'Zero Fill' process means that the line data processing task 820 periodically transmits a specific data pattern that the modem 830 of the public network subscriber can recognize as G3 fax encoding data (about 5 to 6 bytes). (S130).

In the present invention, the specific data pattern is transmitted at intervals of about 1 to 2 times every 5 seconds. The zero fill process is to compensate for the delay time at the beginning of phase 3 and to prevent a "data underflow" error.

The line data processing modem 830 adjusts the window size of the TCP frame packet based on the RTC / CTS hardware flow control according to the state, and uses the adjusted window size and the line data processing modem with the personal computer 800. In operation S170, S180, and S190, the control of the G3 fax data communication between 830 may be performed.

In addition, the line data processing task 820 checks the state of the RTS / CTS, and causes the mobile terminal 810 to control the G3 fax data using a window size already set in the header information of the TCP frame packet. (S200, S210, S220).

This is except that the initial CTS off is set from the line data processing modem 830, and after that, when TCP / IP is set, the data is transmitted with the already set window size (S210), and the mobile terminal 810 corresponding to the corresponding window size. ) Sets the CTS off to the fax emulator (S220), and transmits the G3 fax encoded data to be transmitted to the line data processing task 820 (S240). This is again provided to the line data processing modem 830 to be delivered to the other subscriber's G3 fax phone (not shown) and personal computer (not shown) (S250).

However, when the line data processing task 820 confirms that the CTS on is set from the line data processing modem 830, the G3 fax is not transmitted to the mobile terminal 810 but the window size is "0". The data is transmitted in a TCP frame packet including the data (S180), and the mobile terminal 810 temporarily stops transmitting G3 fax data by transmitting XOFF to the fax-only emulator.

However, if the G3 fax data transmitted between the mobile terminal 810, which is a virtual data terminal (DTE), and the line data processing task 820, may be lost during the transmission process.

At this time, data lost by TCP / IP can be compensated, but the fax modem 830 of the line data processing unit is time sensitive, so if there is no transmission of G3 fax data for a specific time, the fax call is released.

For this reason, the G3 fax data processing method according to the present invention retransmits lost data to delay the release of a fax call when G3 fax data is lost between the mobile terminal 810 and the line data processing modem as described above. During the request process (S380) and the process of re-transmitting the previously requested data (S420), the 'Zero Fill' process is performed from the line data processing task 820, and the line data processing modem 830 as much as the data lost a specific data pattern. To send periodically.

This allows the fax call to continue to be maintained until an 'End Of Page' indicating that all G3 fax data has been transmitted is transmitted to the line data processing modem 830.

In addition to the elements of the present invention described above, another aspect for realizing an efficient G3 fax data communication service is described below.

RLP, mentioned above, is a protocol established between the mobile terminal and the SVM (Selector & Vocoder Module) of a wireless base station. The RLP frame is sent only through a traffic channel in a wireless environment, and G3 fax only when receiving 'Negative Acknowledge' It will retransmit the data.

If the mobile terminal receives a 'NAK' and retransmits a PPP frame due to an error in data transmitted through a wireless section, the time required for transmitting the PPP frame normally is 32 bytes for each frame. Since it is 20ms per second, it takes 60ms to transmit the required PPP frame again, resulting in a 40ms delay due to retransmission.

If the retransmission operation is continued, the RTO (Retransmission Time Out) value is continuously increased, which causes a large time delay in transmitting G3 fax data. Thus, the RTO value is fixed so as not to perform the retransmission operation three or more times.

During fax encoding data transmission, if the transmission speed from the virtual data line termination (DCE) to the called party decreases depending on the public network condition, the fax-only emulator of the personal computer will decrease the transmission speed of the fax data to the mobile terminal. In the present invention, by processing the parameters of the fax-only emulator to fix the transmission speed of the G3 fax data to the value at the time of setting the communication channel (usually 9600bps), even if the public network transmission speed is lowered in the virtual data terminal (DTE) section in FIG. As much as possible to transmit data at the fixed transmission rate (9600bps), it is possible to compensate for the transmission rate inversion in the RLP interval.

The third suggestion is that when the fax-only emulator of a personal computer sends an end of page (EOP) to the mobile data communication control device, the mobile data communication control device sends an 'OK' response. In this case, the waiting time for the 'OK' response after the EOP transmission is about 5 seconds in the case of a wired line. If the 'OK' response is not received within the 5 seconds, the emulator transmits a command for session termination and sends a fax. The call is released.

In the present invention, the time to wait for the 'OK' response after the EOP transmission to at least 30 seconds to secure the release of the fax call as the 'OK' response is delayed by the time delay after the EOP transmission. Here, the waiting time is derived by experiment about 100 seconds.

According to the G3 fax data processing method according to the present invention, using the CDMA mobile communication network provides a G3 fax data processing method using a mobile data communication control device that allows a mobile subscriber to receive a G3 fax data communication service In addition, even when data is lost in the process of transmitting G3 fax data, it is effective to maintain a fax call for G3 fax data communication. In addition, it is expected that G3 fax data communication between mobile subscribers and public subscribers will be possible in future CDMA mobile communication networks.

Claims (8)

In response to a request for G3 fax data communication through the mobile terminal, the mobile data communication control apparatus confirming an idle resource of the line data processing unit and setting up a fax call; Transmitting, via the mobile terminal, a connection message (Pre-Message) indicating that the requested G3 fax data communication is possible as the setting of the G3 fax call is completed; Transmitting the G3 fax data via a mobile terminal as the access message is delivered; Confirming whether the transmitted G3 fax data was successfully delivered; And releasing a fax call as the transmission of the G3 fax data is completed. The G3 fax data processing in a CDMA PCS / DCN according to claim 1, characterized in that a specific data pattern is transmitted to prevent fax call disconnection due to a delay time between a mobile terminal and a modem before the G3 fax data transmission step. Way. 2. The method of claim 1, wherein in the step of transmitting the G3 fax data as the connection message is delivered: Requesting retransmission of the lost G3 fax data when G3 fax data is lost during transmission between the mobile terminal and the mobile data communication control device; Periodically transmitting any data for continuously maintaining the set fax call while waiting for the requested G3 fax data. 4. The method of claim 3, wherein any data for continuing to maintain the fax call is transmitted two or three times periodically for five seconds. The method of claim 1, wherein the transmitting of the G3 fax data as the access message is transmitted, retransmitting the error data generated by the failure of a wireless environment existing between the mobile terminal and the mobile data communication control device. A method of processing G3 fax data in a CDMA PCS / DCN characterized by reducing the time delay caused by subsequent retransmissions by fixing the Retransmission Time Out. 6. The method of claim 5, wherein the fixed retransmission time is fixed such that no retransmission is performed three or more times for the error data. 2. The method of claim 1, wherein in the step of transmitting the G3 fax data, the transmission rate for the G3 fax data transmitted between the mobile terminal and the mobile data communication control device maintains an initial rate regardless of the public network transmission state. A method of processing G3 fax data in a CDMA PCS / DCN. 2. The method of claim 1, wherein in the step of confirming whether the transmitted G3 fax data is successfully delivered, after the fax-only emulator provided in the personal computer transmits an 'EOP' indicating the end of the transmission G3 fax data, the movement data is transmitted. A method for processing G3 fax data in a CDMA PCS / DCN, wherein the waiting time for waiting for a transmission completion confirmation message for G3 fax data from the communication control device is 30 seconds or more.