KR19990038920A - A method for controlling the fax signal of a wireless data communication interlock device in a digital mobile communication network - Google Patents

Abstract

The present invention relates to a fax outgoing call control method of a wireless data communication interworking device in a digital mobile communication network. When transmitting data in a general mobile communication network, there is a problem that data is lost and a part of a fax image is damaged due to a deterioration of a wireless section or a handoff caused by a subscriber's movement. To solve this problem, the transport layer protocol is applied to recover the lost data, the protocol header is compressed at the data link layer to reduce the overhead of the protocol header, and the transmission protocol is satisfied when the fax data is transmitted. A method for controlling a fax call of a wireless data interworking device in a digital mobile communication network capable of performing a reliable fax transmission service by applying a cumulative response method and a flow using a sliding window is proposed.

Description

How to control fax outgoing call of wireless data communication interworking device in digital mobile communication network

The present invention relates to a fax outgoing call control method of a wireless data communication interworking device in a digital mobile communication network.

In general, a wireless data communication network is divided into a wireless local area network and a mobile data network. Mobile data networks are also classified into wireless data networks using dedicated packet networks and cellular mobile telephone networks. Wireless data services that can be provided by such cellular mobile telephone networks include asynchronous data, facsimile services, short message services, and packet data services.

The wireless data service in the conventional cellular network includes data communication in Advanced Mobile Phone System (AMPS), packet data communication in cellular digital packet data (CDPD), and data communication in IS-54 digital cellular network. And data communication in a global system for mobile communication (GSM).

AMPS is an analog mobile telecommunications network and provides fax service using a wireless modem. In addition, GSM, a digital mobile communication network, provides a fax service using a wireless data communication interworking device. In a code division multiple access (CDMA) mobile communication network, only a voice service is provided and a data service, which is a non-voice service, is not yet available. Not provided.

The digital mobile communication network has been developed for voice service, but according to the development of information communication technology and user's demand, the demand for wireless data service that can exchange necessary information as well as existing voice is increasing. In the transmission of such wireless data, the transmitted data may be lost due to deterioration and handoff of the wireless section due to the characteristics of the mobile communication network. In addition, when a fax service is provided as one of non-voice services, a call is cut or a part of a fax image is damaged due to a loss of a fax command.

Accordingly, the present invention applies a transport layer protocol to recover data lost when providing a fax transmission service to a mobile subscriber in a digital mobile communication network, so that even when the wireless section deterioration or handoff occurs, there is no loss of fax commands or data. Fax transmission service can be performed and fax transmission call of wireless data communication interworking device in digital mobile communication network is applied by applying cumulative response method and flow using sliding window to satisfy T.30 protocol when sending fax data. The purpose is to provide a control method.

In the digital mobile communication network according to the present invention for achieving the above object, a method for controlling a call originating by a wireless data communication interworking device may include a call type for a data interworking device requesting call setup to perform a resource state initialization and socket generation process. After determining the idle resources and initializing the selected resources, creating a socket which is an application program interface for communication with the data terminal, and determining the type of call to be serviced. Setting a shape of a protocol, performing a transmission control protocol connection setting process using the socket, and entering a transmission control protocol setting state; and analyzing modem commands received from a mobile subscriber to switch to a fax mode Fax received from subscriber Performing a fax status management and a fax command transmission / reception process for transmitting a command to the modem and receiving response data from the modem and transmitting the command data to the data terminal, and operates in a cumulative response method for packets received from the data terminal. Performing a message transmission and flow control process for performing flow control with the data terminal on the flow control signal of the modem, performing a call termination process after receiving a transmission end message from the data terminal, and terminating the call Disconnecting the transmission control protocol and the point-to-point protocol, and releasing the call in use, initializing the allocated resources, and terminating the resource to perform the protocol connection establishment termination and resource initialization process. It features.

1 is a structural diagram of a digital mobile communication system to which the present invention is applied.

2 is a structural diagram of a wireless data communication interworking apparatus to which the present invention is applied.

3 is a structural diagram of a transport protocol stack to which the present invention is applied;

4 (a) to 4 (d) is a flowchart illustrating a method for controlling a fax call from a wireless data communication interworking apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

11: data terminal 12: mobile terminal

13 base station 14 control station

15: mobile communication switch 16: subscriber location register

17: wireless data communication interlocking device 18: public telephone network

171: relay line matching and switching board 172: IWF management board

173: baud rate control and modem board

31: transmission control protocol 32: manganese protocol

33: subordinate dependent convergence function 34: link control protocol

35: manganese protocol control protocol

36: Point-to-Point Protocol 37: Wireless Link Protocol

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a structural diagram of a digital mobile communication system to which the present invention is applied.

An application program is mounted on the data terminal 11 which is a personal computer, and the mobile terminal 12 is a CDMA portable or vehicle subscriber terminal. The base station 13 is a subsystem for controlling radio matching in the CDMA system, and the control station 14 is a subsystem for controlling the routing of information, various call processing, and soft handoff between the base station 13 and the switching station 15. . The mobile communication exchange 15, which is an exchange station, provides a switching function, and the subscriber location register 16 is responsible for location management and operation of the mobile communication exchange 15 and the subscriber. The wireless data communication interworking device 17 is a device for providing an asynchronous data service, and the mobile communication exchange 15 interworks with the public data network.

2 is a structural diagram of a wireless data communication interworking apparatus to which the present invention is applied.

The wireless data communication interworking device (17 in FIG. 1) provides asynchronous data service to mobile subscribers in a digital mobile communication network, and is a control function for relay line matching with the mobile communication switch (15 in FIG. 1), various resource management, and system control. And a speed matching function for data transmission and reception with the control station 14, a protocol processing function for reliable transmission, and a modem processing function for controlling the modem. Trunk Interface & Switching Assembly (hereinafter referred to as TISA) board 171 performs a trunk circuit matching function, a switching function, and a function of exchanging various signaling with the exchange. The IWF management board (hereinafter referred to as INWA) board 172 is responsible for controlling the interworking function (IWF) system and managing various resources. Rate Adaptation & Modem Assembly (hereinafter referred to as RAMA) The board 173 performs transmission rate adjustment and modem control functions, and a protocol of a transport layer is implemented. The control signals of each board are transmitted through the VME bus through the Dual Port RAM (DPRAM) and the data signals are transmitted through the Serial-Telecommunication (ST) -Bus. The data exchange with the control station (14 in FIG. 1) adds a predetermined preamble to the data to be transmitted and transmits it to the control station (14 in FIG. 1), and transmits the preamble from the data received from the control station (14 in FIG. 1). Use it to find the beginning of the data.

3 is a structural diagram of a transport protocol stack to which the present invention is applied.

Transmission Control Protocol (hereinafter referred to as TCP) 31, which is a transport layer, provides a function of guaranteeing whether packets are lost or reliable delivery of packets and ensuring order, and is a network layer called Internet Protocol (hereinafter referred to as IP). 32 is in charge of routing and status information management in the Internet. Sub-Network Dependent Convergence Function (SNDCF) 33 performs a compression function on the TCP / IP header to increase transmission efficiency. The data link layer comprises a Link Control Protocol (LCP) 34, an Internet Protocol Control Protocol (IPCP) 35, and a Point-to-Point Protocol (PPP) 36. It consists of. This data link layer is used for end-to-end data exchange over a single line and negotiates the initial setup and capacity of the link and TCP / IP header compression. Radio Link Protocol (RLP) 37 is a protocol that supports selection and negative responses for error control of data traffic.

4 (a) to 4 (d) are flowcharts illustrating a method for controlling a fax transmission call of a wireless data interworking apparatus according to the present invention.

The method of controlling fax outgoing call in CDMA digital mobile communication network is largely divided into resource state initialization and socket creation process (41), protocol connection establishment process (42), fax state management and fax command transmission and reception process (43), message transmission and flow control. Process 44, call termination process 45, and protocol connection establishment termination and resource initialization process 46.

When the mobile subscriber selects the transmission speed and the remaining options of the data terminal's fax communication software and makes a dial, the mobile terminal temporarily stores the fax commands in the data interface's application interface layer and responds to the commands. The mobile terminal initiates a call when the data terminal of the mobile subscriber sends a call start modem command to the terminal. After receiving the call start, the mobile communication exchange determines whether it is in a fax service mode as a service option, and then requests a call setup from the wireless data communication companion device (401). The wireless data communication companion device initializes the resource state and creates a socket (41). Do this.

The mobile communication exchange receives a call setup request from the mobile subscriber and makes a line connection request to the wireless data communication interworking device if the current outgoing call is a fax service call. Upon receiving the connection request, the wireless data communication interworking apparatus recognizes that the requested call is an outgoing call, allocates necessary resources, and connects the call path with the exchange through line signaling. In more detail, the wireless data communication interworking device that is requested to set up a call determines a type of a call by using a number of trunks required for occupancy (402) and selects an idle resource (403) to start a service control procedure. The interrupt of the selected pair of modems and speed matcher is then activated (404) and the state of the modem and various environmental variable values are initialized (405). After the initialization process, one socket for exchanging information with the protocol stack module is created (406), the call type is determined (407), and the incoming call control procedure is performed in the case of an incoming call. Perform a manual OPEN (408) to wait for a TCP connection establishment request from the mobile terminal. Thereafter, the protocol connection establishment process 42 is performed.

In the protocol connection establishment process 42, end-to-end connection is performed between the data terminal and the wireless data communication companion device. The end-to-end connection is a negotiation for the configuration of the data link layer and the network layer such as the maximum frame size with the mobile subscriber, the compression content for the protocol header and the assignment of the Internet address. In more detail, after the communication path is established between the wireless data communication interworking device and the mobile terminal, the LCP configuration settings such as the maximum packet size and protocol field compression and stuffing information between the mobile subscriber's data terminal and the wireless data communication interworking device are set. Perform 409. After the LCP shape setting is completed, the IPCP shape setting 410 such as an IP allocation problem and compression is performed between the mobile terminal and the wireless data communication companion device. When negotiating the IPCP configuration, the IP address of the data terminal is assigned by the wireless data interworking device and negotiates the TCP / IP header compression option for effective data transmission in the low-speed radio section. In step 411, the wireless data communication interworking device which has been manually opened performs the TCP connection setup process (412) and then enters the TCP setup state (413). Thereafter, the fax status management and the fax command transmission and reception process 43 are performed.

In the fax status management and fax command transmission / reception process 43, modem setting information is received from a mobile subscriber to recognize a fax transmission mode, the received information is transmitted to the modem, and data is received from the modem and sent to the data terminal. When the receiving party answers and connects to the power station, the modem negotiates with the modem of the power station using the setting information on the fax transmitted from the data terminal. When the negotiation is over and the acknowledgment signal is received, it informs the data terminal that the image can be transmitted. That is, the wireless data communication companion device receiving the fax commands temporarily stored in the data terminal of the mobile subscriber (414) analyzes the received modem commands to specify whether the data is a fax class 2, that is, the fax transmission mode. It is determined whether the command represents (415). As a result of the determination, when the received data is in the fax transmission mode, the system switches to the fax mode, designates the fax status as phase A (416), and analyzes the fax status transmitted and received to manage the status of the fax. Thereafter, the received fax command is transmitted to the modem (417). If the received data is not in the fax transmission mode as a result of the determination in step 415, the received fax command is directly transmitted to the modem without changing the fax status (417). do. Receiving data from the modem receiving the fax command (418) determines whether the fax state is phase A and if a called party identification signal has been received from the power station (419), and if the called party identification signal is received, sends the fax status to phase B If it is switched to 420 and a called party identification signal is not received, the fax state is not switched. Then, using the commands received from the mobile station to negotiate the function identification and reception conditions with the power and transmits the result value to the data terminal. After the negotiation is finished, it is determined whether an acknowledgment signal or a message acknowledgment signal has been received from the power (421). If one of these signals is received, the fax state is switched to phase C (422). Do not. The received data is then sent to the modem (423) and it is determined (424) whether the fax status is phase C. If it is determined that the fax status is not phase C, the process proceeds to receiving data from the mobile subscriber's data terminal (414) or receiving data from a modem (418). The response method is designated as a cumulative response method (425). Thereafter, the message transmission and flow control process 44 is performed.

The message transmission and flow control process 44 operates in a cumulative response manner at the transport layer in order to prevent the modem from being disconnected because there is no data to transmit and to efficiently use a low speed communication path. The flow control between the data terminals of the control using the window of the TCP. In more detail, data is received from the mobile terminal (426) to determine whether the received data is a page break command (427). If the page stop message is received as a result of the determination, the TCP response method, which was a cumulative response method, is deactivated (429), and it is determined whether the command received from the data terminal is the end of the page (439). If the command indicates that the page is at the end of the judgment result, the fax state is changed to phase D. If the command is not the end of the page, the fax state is changed to phase B and data received from the data terminal is transmitted to the modem. (433). In step 427, it is determined whether the data received from the mobile terminal is a page stop command. If the data is not a page stop command, the data received from the data terminal is transmitted 433 to the modem. Data is received from the modem (434), and it is determined whether the data is XOFF as flow information (435). If the result of the determination is that the data received from the modem is XOFF, setting the size of the TCP window to 0 (436) and determining whether the fax state is phase C (440), and determining whether the data received from the modem is XOFF. If the data received from the modem from 435 is not XOFF, it is determined whether the data received from the modem is XON (437). If it is determined that the received data is XON, the size of the TCP window is restored (438), and it is then determined whether the fax state is phase C (440). If the received data is not XOFF or XON, the data is transmitted to the mobile terminal (439), and then it is determined whether the fax state is phase C (440). If it is determined that the fax status is phase C, the process proceeds to step 426 of receiving data from the mobile terminal. If the status is not phase C, it is determined whether the fax status is phase B. Receiving a fax command proceeds to step 414, if not phase B, the call termination process is performed.

In this way, if the transmission termination is received from the mobile subscriber after the transmission of the image is completed, the procedure termination message is transmitted to the power station and the call termination process 45 is performed. That is, the terminal receives the transmission end data from the data terminal (442) and transmits the message end signal to the modem (443). Receiving the data from the modem receiving the message termination signal (444), it is determined whether the data is a message acknowledgment signal (445). In the case of transmitting data to the mobile terminal. Then, it is determined whether the fax status is phase E, that is, whether the call is terminated (448). If the fax status is not phase E, the process proceeds to step 442 of receiving message transmission end data from the mobile terminal. The process terminates the protocol connection establishment and resource initialization process 46.

In the protocol connection establishment termination and resource initialization process 46, the wireless data communication companion device releases the transport layer connection with the data terminal and then disconnects the data link layer. The wireless data communication interworking device terminates the protocol connections and then releases the allocated resources and disconnects the call path with the mobile terminal. More detailed description is as follows. First, the TCP of the wireless data communication companion device releases the connection setting by requesting the connection release to the data terminal (449). When the TCP connection release is completed, the connection establishment of the PPP is terminated (450). When the PPP connection establishment is released, the call release is performed by the mobile communication exchange (451). Thereafter, the allocated resources are initialized (452) and terminated.

As described above, according to the present invention, a mobile subscriber can transmit a fax to a subscriber of a fixed or mobile network capable of receiving a fax by using a data terminal on which a fax program is mounted, and deterioration of a wireless section or movement of a mobile subscriber. In the event of a handoff due to the present invention, it is possible to provide a fax transmission service without losing a fax command or data transmitted. In addition, there is an excellent effect of increasing the success rate of fax transmission by operating the wireless data interlocking device as a dynamic fax server when data transmission is delayed due to a temporary failure of the wireless section.

Claims (4)

In order to perform the resource state initialization and socket creation process, the data interworking device requested call setup determines socket type, selects idle resource, initializes the selected resource, and creates socket which is an application program interface for computer-to-computer communication. Steps, Determining the type of call to be serviced and, in case of an outgoing call, setting the shape of a link control protocol and a network protocol control protocol; Entering a transmission control protocol setting state after performing a transmission control protocol connection setting process using the socket; It analyzes modem commands received from mobile subscribers, switches to fax mode, transmits fax commands received from mobile subscribers to modem, and performs fax status management and fax command transmission / reception processes for receiving data from modem and transmitting to data terminal. Steps, Performing a message transmission and flow control process that operates in a cumulative response manner to a packet received from a mobile terminal and performs flow control with a data terminal on a flow control signal of a modem; Performing a call termination process after receiving the transmission termination message from the mobile subscriber; Disconnecting a transmission control protocol and a point-to-point protocol to perform a protocol connection establishment termination and resource initialization process after the call terminates; And releasing a call in use, initializing the allocated resource, and terminating the allocated resource. The method of claim 1, wherein the facsimile state management and the facsimile command transmission and reception process are performed. Receiving fax instructions that were temporarily stored on a mobile subscriber's data terminal; Analyzing the received modem command to determine whether the command indicates a fax transmission mode; Determining whether the data is in the fax transmission mode, and when the received data is in the fax transmission mode, switching to the fax mode and specifying a fax status as phase A; Transmitting the received fax command to a modem; If it is determined that the fax transmission mode is not the fax transmission mode, transmitting the received fax command directly to the modem without changing the fax status; Receiving data from a modem receiving the fax command; Determining whether the data received from the modem is a called station identification signal; Determining whether the called party identification number is received, and when the called party identification number is received, switching the fax state to phase B; If it is determined that the called party identification number has not been received, maintaining the fax state without switching the status; Negotiating function identification and receivable conditions with the power station using instructions received from the mobile station; Determining whether an acknowledgment signal or a message acknowledgment signal has been received from a large country after the negotiation is finished; If the multipage signal and the message acknowledgment signal are received as a result of the confirmation of the received signal, switching the fax status to phase C; otherwise, not switching the fax status; If it is determined that the fax status is phase C and the fax status is not phase C, the steps of receiving fax commands of the data terminal of the mobile subscriber and receiving data from a modem; And determining that the fax status is phase C, and if the fax status is phase C, designating a response method of a transmission control protocol as a cumulative response method. To control fax outgoing calls on your computer. The method of claim 1, wherein the message transmission and flow control process comprises: checking whether data received from the data terminal is a page stop command; Deactivating a transmission control protocol response method which was a cumulative response method when a page stop message is received as a result of the confirmation of the received message; Determining whether the data received from the data terminal is a command indicating the end of a page; If it is determined that the data received from the data terminal is a command for indicating the end of the page, the step of switching the fax state to phase D; If it is determined that the data received from the data terminal is a command for indicating the end of the page, and if it is not a command indicating the end of the page, switching the fax state to phase B and transmitting the data received from the data terminal to the modem; , Checking whether the data received from the data terminal is a page stop command; if not a page stop command, transmitting data received from the data terminal to a modem; Receiving data from the modem to determine whether the data is XOFF which is flow information; If the data received from the modem is XOFF as a result of determining whether the data of the modem is flow information, determining whether the fax state is phase C after setting the size of the transmission control protocol window to 0; Determining whether the data received from the modem is XON if the data received from the modem is not XOFF; Judging whether the data received from the modem is XON, and if the received data is XON, determining whether the fax state is phase C after restoring the size of the transmission control protocol window; Judging whether the data received from the modem is XON, and if the received data is not XON, determining whether the fax state is phase C after transmitting the data received from the modem to the data terminal; Determining that the fax status is phase C, and if the fax status is phase C, proceeding to receiving data from a data terminal; Determining whether the fax is in phase B when the fax is not in phase C as a result of determining whether the fax is in phase C; Determining that the fax status is phase B, and if the fax status is phase B, proceeding to a fax status management and a fax command transmission and reception process; And determining that the fax status is phase B, and if the fax status is not phase B, performing a call termination process. The method of claim 1, wherein the call termination process comprises: receiving a message transmission termination signal from a data terminal; Transmitting the message transmission end signal to a modem; Determining whether the data received from the modem is a message acknowledgment signal by receiving data from the modem receiving the message transmission end signal; Determining whether the data received from the modem is a message acknowledgment signal, and if the message acknowledgment signal is a message acknowledgment signal, switching the fax state to phase E and transmitting the data to the data terminal; If it is determined that the data received from the modem is a message acknowledgment signal, and if it is not a message acknowledgment signal, transmitting a response to the data terminal directly; Determining whether the fax status is phase E, Determining that the fax status is phase E, and if the fax status is not phase E, proceeding to receiving message transmission end data from a data terminal; And determining that the fax status is phase E. If the status E is phase E, the call is terminated. The method of claim 1, further comprising the step of ending the call.