JPH08195784A - Data transmission system and data transmission method - Google Patents

Abstract

PURPOSE: To set the operation of an analog data modem even when a channel between a terminal equipment and the analog data modem to be set for communication via a digital channel is not connected. CONSTITUTION: A terminal equipment DTE1 outputs an operation setting command to initialize an analog data modem 6. Then a modem control command analysis section 52 stores an operation setting command to a modem control command memory 51 and returns a reply signal to the terminal equipment DTE1. Then the terminal equipment DTE1 sends a transmission request command. Thus, an analog telephone line network SL selects a corresponding subscriber line and sends a received call to the analog data modem MOD20. Then the modem control command stored in the modem control command memory 51 is transferred to the analog data modem 6, in which a command is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission system and a data transmission system suitable for use in transmitting data of a personal computer using a transmission line slower than an analog transmission line or a transmission line with a relatively large number of line errors. It relates to a transmission method.

[0002]

2. Description of the Related Art When an analog data modem such as an MNP modem is connected via an analog line network, the modem is operated by inputting a predetermined command from a personal computer or the like directly connected to the analog data modem. Performs initial settings and control. Such modem control is similarly performed when the analog data signal is PCM-modulated and is artificially transmitted as a voice signal using the digital line network.

FIG. 9 shows a case where data is exchanged between data terminal devices connected to an analog data modem via an analog line network. DTE1 and DTE2 shown in this figure are terminal devices such as personal computers, respectively, and are analog data modems MOD1.
0, input and output of data via MOD20. The analog data modems MOD10 and MOD20 are, for example, M
It is an NP modem or the like and is connected via an analog telephone line network SL which is an analog transmission network.

Next, the terminal devices DTE1 and DT shown in FIG.
The data transfer sequence of E2 will be described with reference to FIG. Here, from the terminal device DTE1 to the terminal device D
Take the case of transferring data to TE2 as an example. First, the terminal device DTE1 transmits an operation setting command 21 to the analog data modem MOD10 to perform initial setting. The command transmitted at this time is, for example, "AT \ N2%
It is a code such as "C3 &K3". When the operation setting command 21 can be set, the analog data modem MOD10 sends the response signal (“OK”) 22 to the terminal device DT.
Return to E1. Next, the terminal device DTE1 sends a call request command 2 to the analog data modem MOD10.
3 is sent out. This command is, for example, "ATD03
123456 ”and the like. When the call request command 23 is supplied, the analog data modem MOD10 sends a call request 2 to the analog telephone line network SL.
4 is transmitted, and as a result, an incoming call signal 25 is output from the analog telephone line network SL to the analog modem MOD20. As a result, the analog data modem MOD20 outputs the incoming call display (RING) 26 to the terminal device DTE2 and executes the inter-modem negotiation process 27.

When the negotiation process 27 is successful, the analog data modem MOD10 sends a connection signal (CONNECT) 28 to the terminal device DTE1, and the analog data modem MOD20 sends a connection signal (CONNECT) 29 to the terminal device DTE2. Sent. As a result, the data transfer mode (reference numeral 30) is entered, and the transmission and reception of the data signal is started between the terminal devices DTE10 and DTE20. The terminal device DTE2
When the data is transferred from the terminal device DTE1 to the terminal device DTE1, the processes of DTE1 and DEE2 in the above-described sequence are simply exchanged.

By the way, in the data transfer mode, there has been proposed a method of changing the operation mode of the analog data modem and switching to the command mode during communication by a command from the terminal device, for example, Japanese Patent Publication No. 6-4674.
No. 1 is disclosed. Here, this method will be described with reference to FIG. In FIG. 11, 31 is an escape instruction, which is composed of a code indicating a predetermined symbol (+ symbol in the figure) and a no-data period of a predetermined period provided at least one of before and after this code. When the escape command 31 is supplied to the analog data modem MOD10 shown in FIG. 9, the analog data modem MOD10 sends the response signal 33 to the terminal device DTE.
It returns to 1 and switches from transparent mode to command mode.

In the in-communication command mode, when the command setting confirmation command 34 (for example, a code such as AT ¥ S) is output from the terminal device DTE1, the analog data modem MOD10 outputs the command list data 35 to the terminal device DT.
Send to E1. The terminal device DTE1 can know what command is set in the analog data modem MOD10 by decoding the command list data 35.

Next, when the terminal device DTE1 outputs the data mode restoration command 36 (for example, a code such as ATO), the analog data modem MOD10 causes the connection signal (C
CONNECT) 38 to the terminal device DTE1 and returns to the data transfer mode.

On the other hand, there has been proposed a data transfer system for transmitting a data signal of an analog data modem by using a low speed digital line having a transmission speed equal to that of the analog data signal. Such a system is shown, for example, in Japanese Patent Application No. 3-73016 (corresponding to claim 3 thereof), which uses a communication protocol for digital lines in the digital line section and modem communication in the analog line section. Use protocol. By adopting such a method, it is possible to suppress a significant decrease in data transmission efficiency due to a transmission error even in a low speed line such as a wireless transmission line for mobile communication.

FIG. 12 is a block diagram showing the structure of this type of data transmission system. In this figure, parts corresponding to those in FIG. 9 are designated by the same reference numerals. Now, the adapter devices ADP10 and ADP20 shown in FIG. 12 are connected by the digital line network DL, and the interface line I is connected to the adapter device ADP10.
The terminal device DTE1 is connected via L1. On the other hand, the terminal device DTE2 is an analog data modem MOD.
The analog telephone line network SL, which is an analog transmission network, is connected via 20 and the other end of the analog telephone line network SL is connected to the adapter device ADP20.

The adapter device ADP20 includes an analog data modem 6, a digital line communication protocol control unit 5 and a frame synchronization control unit 4. The analog data modem 6 is an analog data modem MOD2.
A function of demodulating a modem signal transmitted from 0 through the analog telephone line network SL into digital data, and a digital data signal reproduced by the digital line communication protocol control unit 5 is converted into a modem signal to obtain an analog telephone line. It has a function of sending to the network SL.

Communication protocol control unit 5 for digital line
Performs control for connecting between the adapter devices ADP10 and ADP20 in accordance with a communication protocol dedicated to the digital transmission path. The frame synchronization control unit 4 has a function of adding a frame synchronization signal to the transmission digital signal transferred from the digital line communication protocol control unit 5 to form a data frame, and transmitting this data frame to the digital line network DL. , Has a function of receiving the data frame transmitted through the digital line network DL in synchronization, decomposing the received data frame, and transferring it to the digital line communication protocol control unit 5 as a received digital frame.

On the other hand, the adapter device ADP 10 includes a terminal device connection termination unit 1, a digital line communication protocol control unit 2, and a frame synchronization control unit 3. The terminal device connection termination unit 1 transmits / receives a data signal to / from the terminal device DTE, and converts the data signal format between the terminal device DTE1 and the digital line communication protocol control unit 2. The digital line protocol control unit 2 assembles the digital data signal transmitted from the terminal device DTE1 into a digital data signal in accordance with the communication protocol dedicated to the digital transmission line, and sends it to the digital line network DL via the frame synchronization control unit 3. When transmitting and receiving the digital data signal transmitted via the digital circuit network DL, the data signal is reproduced according to the communication protocol dedicated to the digital transmission line, and the terminal device is connected via the terminal device connection terminating unit 1. Send to DTE1. The frame synchronization control units 3 and 4 have the same function. According to the configuration described above, it is possible to suppress a decrease in data transfer efficiency by using different communication protocols for the digital line and the analog line.

[0014]

However, as shown in FIG.
The data transmission system shown in (1) has various problems to be improved as follows. First, in the above system, when the terminal device DTE1 is in a standby state before making a call to the terminal device DTE2, that is, the terminal device DTE1 and the analog data modem 6 in the adapter device ADP20 are connected via the digital line network DL. When it is not set, the modem operation settings necessary for communication cannot be set. In other words, the terminal device D
The operation setting command cannot be directly transmitted from the TE1 to the analog data modem 6. Therefore, the analog data modem 6 can be operated only in a preset setting state.

Next, in the data transfer mode after the communication protocol is established, a data error occurring in the digital line network DL between the digital line communication protocol control unit 2 and the digital line communication protocol control unit 4 is detected. It is recovered by ARQ (Automatic Retransmission Request Method). Therefore, when the data transmitted from the terminal device DTE1 is received by the analog data modem 6, the data is transmitted error-free, but the reception timing and the reception speed are in the state of the data error occurring in the digital line network DL. It changes every moment. Therefore, even if the escape command 31 shown in FIG. 11 is used, there is a possibility that the mode cannot be switched to the command mode. That is, the escape command 31 includes a no-data section of a predetermined length, but in a situation where the reception timing and the reception speed change momentarily, the no-data section of the predetermined length cannot be detected, so the escape instruction 31 is decoded. I can't
Could not switch modes.

The present invention has been made in view of the above-mentioned circumstances. A first object of the present invention is to provide an analog even when the terminal and the analog data modem are not connected via the digital line network DL. An object of the present invention is to provide a data transmission system capable of setting the operation of a data modem. A second object of the present invention is to provide a data transmission system capable of reliably switching the operation mode of an analog data modem even when the system is in a data transfer state.

[0017]

In order to solve the above problems, in the invention described in claim 1, there is provided a first analog-digital mutual conversion provided between an analog transmission line and a digital transmission line. Data transmission having a data relay device and a second data relay device provided on the other end side of the digital transmission path, and the first and second data relay devices being configured to perform incoming and outgoing call control. In the system, the first data relay device includes: (a) a modem unit that transmits and receives data to and from an analog data modem connected to the other end of the analog transmission line according to an analog communication protocol; The data transferred from the modem section is sent to the digital transmission line in accordance with the digital communication protocol, and the data is transmitted from the digital transmission line. And a first digital line control unit for transferring the received data in accordance barrel for communication protocols on the modem unit, the second data relaying apparatus,
(A) When the digital data supplied from the external terminal device is an operation setting command for setting the operation state of the modem unit, the modem imitation means for imitating the processing procedure in the modem unit and responding to the terminal device And (b) a command storage unit that stores an operation setting command that is a target to be imitated by the modem imitating unit; and (c) the command setting unit that responds to a command from the terminal device after the imitation by the modem imitating unit is completed. A call request request control means for making a call request to the first data relay device; and (d) the command stored in the command storage unit after the incoming call corresponding to the call request is made. Command transfer means for transferring to the modem section of the data relay device, and (e) data other than the command transferred from the terminal device is transferred in accordance with a digital communication protocol. A second digital line control unit for transmitting to the terminal device the data received from the digital transmission line in accordance with a digital communication protocol, and the analog data modem unit for transferring the command. When the command transfer is performed by the means, the analog data modem of the destination connected to the analog transmission line is negotiated to shift to the data transfer mode.

Further, in the invention described in claim 2,
In the data transfer mode, when the digital data supplied from the external terminal device is a command designating a mode in which the command should be responded, the command is converted into predetermined code information and the second digital line is converted. When the digital data supplied from the control unit and the external terminal device is a command for the modem unit, the processing procedure in the modem unit is imitated to respond to the terminal device, and Command processing imitating means for terminating the processing, wherein the command processing imitating means reproduces the code information sent by the second digital line control unit into a command by the first digital line control unit, and , And operates after the command is accepted by the modem unit.

According to the third aspect of the present invention, the command processing imitating means in the modem section when the digital data supplied from the external terminal device is a command requesting a list of setting commands. It is characterized in that the processing procedure is imitated, the list of commands in the command storage means is returned to the terminal device, and this processing is terminated.

According to another aspect of the invention, there is provided a first data relay device for analog-digital mutual conversion provided between the analog transmission line and the digital transmission line,
A second data relay device provided at the other end of the digital transmission line, and the first and second data relay devices are configured to perform incoming and outgoing call control, and the first data relay device is provided. (A) a modem unit for transmitting / receiving data to / from an analog data modem connected to the other end of the analog transmission line in accordance with an analog communication protocol; and (b) digital data transferred from the modem unit. A first digital line control unit for transmitting to the modem unit the data received from the digital transmission line according to the digital communication protocol according to the digital communication protocol, and the second data. The relay device (a) uses the data other than the command transferred from the terminal device according to the digital communication protocol. In the data transmission system having a second digital line control unit for transmitting the data received from the digital transmission line according to the digital communication protocol to the terminal device, When the digital data supplied from the terminal device is an operation setting command for setting the operation state of the modem unit,
A first step of responding to the terminal device by imitating the processing procedure in the modem section; and (b) a second step of storing in the storage means the operation setting command that is imitated by the imitating means in the first step. And (c) a third step of making a call request to the first data relay device in response to a command from the terminal device after the first step is completed, and (d) the call A fourth step of transferring the command stored in the storage means to the analog data modem section of the first data relay device after an incoming call corresponding to the call request is made.
And (e) after the completion of the fourth step, perform a negotiation between the destination analog data modem connected to the analog transmission line and the modem section to shift to the data transfer mode. Is characterized by.

Further, in the invention described in claim 5,
5. The data transmission method according to claim 4, wherein when the digital data supplied from the external terminal device is a command instructing a mode to respond to the command, the command is converted into predetermined code information and the first code information is converted into the predetermined code information. No. 2 digital line control unit, a code information sending process, a playing process of playing the code information sent by the second digital line control unit into a command by the first digital line control unit, and the playing process. After the command reproduced by is accepted by the modem section,
When digital data supplied from an external terminal device is a command to the modem unit, a command imitation process of responding to the terminal device by imitating a processing procedure in the modem unit and terminating this process is performed. It is characterized by having.

In a sixth aspect of the present invention, in the command imitation process, when the digital data supplied from the external terminal device is a command requesting a list of setting commands, the processing procedure in the modem section is performed. It is characterized in that the list of commands in the command storage means is imitated and returned to the terminal device, and this processing is terminated.

[0023]

According to the invention described in claims 1 to 6, when the external terminal device sends the operation setting command of the modem section, the second data relay apparatus responds to the terminal apparatus by an operation imitating the modem section. . Therefore, the terminal device operates as if a command was directly set in the modem section. Then, when the analog data modem as the communication partner receives the call and the digital transmission path between the first and second data relay devices is connected, the command to be imitated is read from the storage means, 2 is transferred to the modem section in the data relay device. As a result, the operation setting of the modem section is performed, and the data transfer mode is set through the negotiation process.

According to the second and fifth aspects of the present invention, when a mode to respond to a command is instructed from the external terminal device in the data transfer mode, the command indicating the instruction content is predetermined. It is converted into code information and transferred to the first digital line controller. And the first
In the digital line control unit, the transferred code information is reproduced as a command based on the transferred code information and transferred to the modem unit. As a result, the mode of the modem section is switched. When the command for the modem unit is supplied from the terminal device after the mode of the modem unit is switched, the first data relay device responds to the terminal device by imitating the processing procedure in the modem unit. , And terminate this process.

According to the third and sixth aspects of the present invention, when the command requesting the list of setting commands is supplied from the terminal device, the second data relay device imitates the processing procedure in the modem section, and The list of commands in the storage means is returned to the terminal device, and this processing is terminated. As a result, the terminal device performs the same process as when the command confirmation request is directly executed to the modem unit.

[0026]

【Example】

A: First Embodiment (Configuration of Embodiment) Next, an embodiment of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In addition, in this figure, FIG.
The same reference numerals are given to the portions corresponding to the respective portions, and the description thereof will be omitted. In addition, this embodiment is an embodiment in which the present invention is applied to a mobile communication system, in which the digital circuit network DL shown in FIG. 12 is replaced with a wireless digital circuit DL ', and the adapter device ADP20 is provided in the mobile communication switching center MCX. The major difference in the system is that it is provided in.

First, the configuration of the adapter device ADP10 in this embodiment will be described. First, reference numeral 50 indicates V.I. 24 is an interface unit, and the terminal device DTE
Data is exchanged between 1 and the modem control command analysis unit 52. In addition, the interface unit 50 and the terminal device D
It is connected to TE1 by a digital interface line.

The modem control command analysis section 52 analyzes the command transferred from the terminal device DTE1 via the interface 50 and sends a response signal or the like to the terminal device DTE1. Further, the modem control command analysis section 52 writes the command to be set in the analog data modem 6 in the modem control command memory 51. In this case, the modem control command analysis section 52 performs an operation imitating the analog data modem 6 in the adapter device ADP 20 (details will be described later). Next, 53 is a control unit that controls each unit of the apparatus, and controls the operations of the switching unit 54 and the digital mobile unit MS, for example, based on the analysis result of the modem control command analysis unit 52. Under the control of the control unit 53, the switching unit 54 connects either the modem control command memory 51 or the modem control command analysis unit 52 to the digital line communication protocol control unit 2.

On the other hand, the digital radio base station BS receives the transmission signal from the digital mobile station MS and transfers it to the mobile communication switching center MCX, and at the same time, the mobile communication switching center MCX.
The signal sent from the mobile station is transferred to the digital mobile station MS. The mobile switching center MCX uses the adapter device ADP20.
And a control unit 63, and the adapter device ADP 20 includes a digital line communication protocol control unit 5, V.V. It has a 24 interface 61 and an analog data modem 6. The control unit 63 transfers the transmission control signal received by the digital radio base station BS to the analog telephone network SL.
Further, analog telephone network SL selects the subscriber line corresponding to the subscriber number included in the transmitted outgoing call control signal. In the above-described configuration, the digital mobile station MS and the digital radio base station BS each have a frame synchronization control unit (see reference numerals 3 and 4 shown in FIG. 12).

(Operation of Embodiment) Operation from Communication Standby State to Data Transfer Mode Next, the operation of this embodiment having the above-mentioned configuration will be described. First, the operation from the communication standby state to the data transfer mode will be described. To do. First, mobile communication switching center MC
In order to initialize the analog data modem 6 in X, the terminal device DTE1 outputs a modem control command.
That is, as shown in FIG. 2, the operation setting command (“AT ¥ N2% C3 & K3” in the illustrated example) 11 is output. Then, the operation setting command 11 is transferred to the modem control command analysis unit 52 via the interface unit 50, and is analyzed here. When it is determined in this analysis that the operation setting command 11 can be set, the modem control command analysis unit 52 stores the operation setting command 11 in the modem control command memory 51, and also, as shown in FIG. (“OK”) 12 to terminal device D
Return to TE1.

In this case, the modem control command analysis unit 52
, Which imitates the operation of the analog data modem 6, the terminal device DTE1 receiving the response signal 12 determines that the command setting for the analog data modem 6 has been normally performed. At this point, since the digital radio line DL 'is not connected, the terminal device DT
It is not possible for E1 to set commands directly in the analog data modem 6.

Next, the terminal device DTE1 sends a call origination request command ("ATD0312 in the illustrated example" as shown in FIG.
34567 ") 13 is transmitted. The transmission request command 13 is analyzed by the modem control command analysis section 52 and notified to the control section 53. As a result, the control unit 53
Creates a transmission control signal 14 (see FIG. 2) and transfers it to the digital mobile station MS. The digital mobile device MS is
The transmitted call control signal 14 is transferred to the digital wireless line D
It transmits to the digital radio base station BS via L '.

The digital radio base station BS which has received the transmission control signal 14 transfers it to the control unit 63 via the control line 58. As a result, the control unit 63 sends the transmission control signal 14 to the analog telephone line network SL, the analog telephone line network SL selects the corresponding subscriber line, and calls 15 to the analog data modem MOD20 (FIG. 2). ). Then, the analog data modem MOD20 outputs an incoming call display (RING) 16 to the terminal device DTE2, whereby the terminal device DTE2 knows the incoming call. A control signal transmission method for such an outgoing / incoming call is, for example, R, which is a Japanese standard for digital car telephone systems.
It is shown in CR-STD27C.

On the other hand, the control unit 53 in the adapter device ADP10 controls the switching unit 54 to connect the modem control command memory 51 and the digital line communication protocol control unit 2. Then, the digital line communication protocol control unit 2 reads the modem control command 11 stored in the modem control command memory 51 and outputs it as the command A from the digital mobile station MS. At this time, since the connection of the digital line is completed as described above, the command A is transmitted via the digital radio base station BS.
The data is transferred to the analog data modem 6 in the adapter device ADP20. As a result, command setting is performed in the analog data modem 6, and the response signal B to this is set
("OK") is transferred to the digital line communication protocol control unit 2 via the digital radio base station BS and the digital mobile station MS (see FIG. 2).

Then, the analog data modem 6 which has made the command setting negotiates 1 with the analog data modem MOD20 via the analog telephone line network SL.
7 (see FIG. 2). When this negotiation 17 ends, the analog data modem MOD20 transmits a connection signal (“CONNECT”) 19 to the terminal device DTE2, and similarly, the analog data modem 6 in the adapter device ADP20 sends the signal C indicating the connection to the digital radio. Control unit 53 via base station BS and digital mobile unit MS
Transfer to. As a result, the control unit 53 causes the modem control command analysis unit 52 to output a connection signal (“CONNECT”).
18 is output and transferred to the terminal device DTE1, and the switching section 54 is controlled to connect the digital line communication protocol control section 2 and the modem control command analysis section 52.

Through the above processing, both the terminal device DTE1 and the terminal device DTE2 receive the connection signal. As a result, as shown in FIG. 2, the data transfer mode is entered, and data transfer is performed between the terminal device DTE1 and the terminal device DTE2. By the above-mentioned operation, it is possible to shift from the terminal standby state to the data transfer mode, and a more general operation in this case is shown in FIG.

First, the processes from step SPa1 to step SPa8 shown in FIG. 3 are sequentially performed, whereby the operation from sending the response signal 12 to storing the command in the modem control command memory 51 shown in FIG. 2 is completed. At this time, the modem control command analysis unit 52, if the input command is not settable, the step SPa
Step SPa9 is executed instead of 7, 8 and the terminal device D
An error message (“ERROR”) is sent to TE1 and the process returns to step SPa1. As a result, the terminal device DTE
The operator of No. 1 knows the error of the command from the error message sent in step SPa9.

If the correct command is input, the process goes from step SPa1 to step SPa5 again, and then proceeds from step SPa5 to step SPa10.
Further, the processing of steps SPa11 to SPa15 is performed. This completes the operation shown in FIG. However,
When the modem control command analysis unit 52 cannot receive the response signal B shown in FIG. 2, the determination in step SPa12 is “NO”, and the process returns to step SPa1 again via step SPa9.

Further, the modem control command analysis section 52
If the connection signal C shown in FIG. 2 cannot be received, the process proceeds to step SPa16, and the terminal device DTE1 displays “NO”.
The CARRIER signal is transmitted to notify that the connection with the analog data modem 6 has failed. Then, the process proceeds to step SPa17, shifts to the command mode, sends a list of setting commands to the terminal device DTE1, and then shifts to step SPa1. In this case, step SPa1
By the process of 7, the terminal device DTE1 can confirm what command has been set, and if an inappropriate setting is made, this is corrected in step SPa1.

On the other hand, when the digital mobile unit MS receives the incoming signal, the determination in step SPa2 is "YES".
Then, move to step SPa20, and "automatic incoming call permission"
Is determined. If this determination is “NO”, the processing of step SPa2 and step SPa20 is cycled. If the automatic incoming call is permitted, the process proceeds from step SPa20 to step SPa21, and the terminal device D
Send an incoming call indication (RING) to TE1. After that, the processing proceeds to step SPa11, and the same processing as in the case of the above-mentioned transmission is performed.

Command Mode Switching Operation in Data Transfer Mode Next, the process of shifting to the command mode while the data transfer mode is set will be described. First, as shown in FIG. 4, the escape instruction 31 is sent from the terminal device DET1 to the adapter device ADP10. The escape command 31 is the same signal as that described in FIG. 11, and is transferred to the modem control command analysis unit 52 and analyzed. When the modem control command analysis section 52 decodes the escape instruction 31, it causes the digital line communication protocol control section 2 to issue an escape notification D. That is, as shown in FIG. 4, the digital line communication protocol control unit 52 transmits the notification D indicating that the escape command has been received using the digital line communication protocol. This notification D is issued by the digital mobile device M.
S is transferred to the digital radio base station BS,
It is input to the communication protocol control unit 5 for digital line. The digital line communication protocol control unit 5 reproduces the escape command 31 and supplies it to the analog data modem 6 via the interface unit 61. As a result, the analog data modem 6 transmits a response signal (“OK”) 32 indicating that the reception has been confirmed to the digital line communication protocol control unit 5 and shifts to the command mode. The response signal 32 is converted into a response notification E in the communication protocol control unit 5 for digital line (see FIG. 4) and transmitted from the digital radio base station BS according to the protocol for digital line. Then, the response notice E is received by the digital mobile unit MS and transferred to the digital line communication protocol control unit 2. Then, the response notification E is demodulated as the response signal 33 and supplied to the terminal device DTE1 via the modem control command analysis unit 52. As a result, the terminal device DTE1 knows that the analog data modem 6 has accepted the escape command.

Next, when the command setting confirmation command ("AT \ S") 35 is output from the terminal device DTE1, the modem control command analysis section 52 stores the command set at the start of communication from the modem control command memory 51. reading,
This is transferred to the terminal device DTE1. This allows the terminal to know what command the DTE 1 has set. In this case, the terminal device DTE1 receives the command list stored in the modem control command memory 51, which is the same as the command set in the analog data modem 6 (see command A in FIG. 2). For the DTE 1, it is the same as receiving the command list directly from the analog data modem 6. Since the command setting confirmation instruction 35 is completed by being processed by the modem control command analysis unit 52, it is not transferred to the analog data modem 6 side.

Next, when the terminal device DTE1 outputs a return command ("ATO") 36, this is transferred to the digital line communication protocol control unit 2 via the modem control command analysis unit 52, where the digital line is transmitted. Is converted into a return instruction F according to the protocol for. And
The return instruction F is transmitted to the digital line communication protocol control unit 5 via the digital line DL, where it is demodulated by the return instruction 36 and transferred to the analog data modem 6. As a result, the analog data modem 6 returns to the data transfer mode, and the connection signal (“CONN
ECT ") 37 is output. This connection message 37
Is converted into a connection signal G in the digital line communication protocol control unit 5 and transferred to the digital communication protocol control unit 2 via the digital radio line DL.
In the digital communication protocol control unit 2, the connection signal G is demodulated into a connection signal (“CONNECT”) 38 and the terminal device DT is passed through the modem control command analysis unit 52.
Transfer to E1. As a result, the terminal device DTE1 knows that the terminal device DTE2 has accepted the shift to the transfer mode, and thereafter the data transfer mode is restarted.

By the above-mentioned operation, the data transfer mode can be shifted to the command mode, and a more general operation in this case is shown in FIG. First, step SP
In b1, it is determined whether or not communication is in progress, and if "NO", the flow shifts to the subroutine shown in FIG. That is, in this case, since the communication is on standby, the above-described operation is performed.

On the other hand, in step SPb1, "YE
S ", and further steps SPb2 to SPb6
By performing the processing of 1, the transition to the command mode is performed. Then, the setting command list 35 (see FIG. 4) is transferred to the terminal device DTE1 by the processing of steps SPb7 and SPb8. After that, return command 36
The process of steps SPb7 and SPb9 is circulated until is output, and when the return command 36 is output, the process proceeds to step SPb10 to transfer the return command F to the digital wireless line DL '.

Thereafter, steps SPb7, SPb9, SPb10, S are executed until the connection signal G (see FIG. 4) is received.
The process of Pb11 is circulated. When the connection signal G is received, the process proceeds to step SPb12 and the terminal device DTE
The connection signal is transmitted to 1 and the mode returns to the data transfer mode (step SPb13). The processing shown in FIG. 4 is executed by the above processing.

On the other hand, if the response signal E cannot be received, the determination at step SPb4 becomes "NO" and the process returns to step SPb1. If the escape instruction cannot be detected, the process returns to step SPb1. . here,
The process of step SPb2 for determining whether the signal output from the terminal device DTE1 is the escape instruction will be described. FIG. 6 is a flowchart showing the processing of step SPb2 in more detail. Step SP shown in this figure
In c1, first, it is determined whether or not the character "+" used in the escape command is received. That is, in this embodiment, since the escape instruction as shown in FIG. 7 is used, it is determined whether or not the used character "+" is detected. In FIG. 7, α is a no-data period placed before and after the used character string, and needs to be a period of a predetermined length or more. Further, β is a period between the used characters and needs to be a period of a predetermined length or less. Here, for the periods α and β, conditions (1), (2), (3), and (4) are set as shown in FIG. 7.

Now, in FIG. 6, when the determination at step SPc1 is "YES", the routine proceeds to step SPc2,
Data transmission to the digital radio line DL is held. Then, steps SPc3, SPc4, SPc5,
In sPc6, the above-mentioned conditions (1), (2),
It is determined whether (3) and (4) are satisfied.
If all the conditions are met, step SPc
7, the escape command is determined, the escape character string (+++++) is deleted, and the process proceeds to step SPb3 shown in FIG.

On the other hand, if "NO" is determined in any of the steps SPc3 to SPc6, the process proceeds to step SPc8 to release the data transmission hold to the digital radio line DL ', and then proceeds to step SPc9.
If "NO" is determined in step SPc1, the process immediately proceeds to step SPc9. In step SPc9, the data received from the terminal device DTE1 is sent to the digital radio line DL '. This is because the received data is not the escape command and the terminal device D
This is because it is normal data to be transferred to the TE2 side.
After the processing of step SPc9, the process returns to step SPb1 shown in FIG.

B: Second Embodiment (Structure of Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is an embodiment in which the system of the first embodiment described above is applied to a digital mobile phone system. In the figure, 100 is a mobile device, 200 is a radio base station, 300 is a mobile communication switching center, 4
00 is a telephone network, and 500 is an analog data modem. A telephone 101 and a data signal converter 105 are connected to the mobile device 100, and the data signal converter 1
A data terminal 102 is connected to 05. In this case, the data signal converter corresponds to the adapter device ADP10 in the first embodiment described above.

The mobile unit 100 also includes a voice signal conversion circuit 104, a control device 106, and a communication wireless transmission / reception circuit 10.
7. Control wireless transmission / reception line 108 and switching circuit 109
have. The mobile switching center 300 has switch circuits 301a and 301b. The two adapter devices ADP310 are provided between these switch circuits.
Also, the ADP 311 and one audio signal control unit 312 are provided in parallel, and any one of them is selected by the switch circuits 301a and 301b. In this case, the switch circuits 301a and 301
The switching operation of b is controlled by the control device 309.

The audio signal control unit 312 includes a signal conversion circuit (type A) 302, an audio signal conversion circuit 305 and P.
The adapter device A including the CM code decoding circuit 308
The DP 310 includes a signal conversion circuit (type B) 303, a modulation / demodulation device (type B) 306, and a PCM code decoding circuit 3.
08. The adapter device ADP 311 includes a signal conversion circuit (type C) 304 and a modulation / demodulation device (type C) 3.
07 and a PCM code decoding circuit 308. Next, the analog data modem 500 has a network control device 504 and a modulation / demodulation device 503. A telephone 501 is connected to the network control device 504, and the modulation / demodulation device 50 is connected.
A data terminal 502 is connected to 3.

(Operation of Embodiment) Next, the operation of this embodiment having the above-mentioned structure will be described. First, in the digital mobile phone system, since a voice call is a basic service, the mobile device 100 normally uses the voice signal conversion circuit 104, and the data signal conversion device 105 is switched by the switching circuit 109 to be used. It Also,
Even in the mobile switching center 300, the voice signal conversion circuit 302 and the data signal conversion devices 303 and 304 are appropriately switched and used. In this case, the data signal converters 303 and 304 are switched and used according to the type of the data signal converter 105 on the mobile device side. The switching operation of the audio signal control unit 312 and the adapter devices ADP 310 and 311 in the system shown in FIG. 8 will be described below.

First, the data to be transmitted to the data terminal 502 on the public communication network side is the data terminal 10 on the mobile unit 100 side.
The case of occurrence in 2 will be described. In this case, the data signal conversion device 105 connected to the data terminal device 102 having the data information to be transmitted controls the same type as the modulation / demodulation device 500 used by the data terminal 502 of the communication partner via the control line 110. To the device 106. As a result, the control device 106 controls the switching circuit 109,
The data signal converter 105 is connected to the mobile device 100.
Then, the call is made after the connection is completed. In this case, the call control between the mobile device 100 and the mobile communication switching center 300 is performed, for example, in the same manner as the connection control for the car telephone exchange, but the mobile device 100 uses the call signal for the other terminal. Information including the type of the modulator / demodulator is included and transmitted via the control wireless transmission / reception circuit 108.

The information indicating the type of the modulation / demodulation device transmitted from the mobile unit 100 is transmitted via the control radio transmitting / receiving circuit 202 of the radio base station 200, the base station control circuit 204 and the control line 205 to the mobile communication switching center. It is received by the control device 309 of 300. As a result, the adapter device ADP310 or AdP corresponding to the type of the modem device is used.
Any one of 311 is selected. Also, if necessary, the control device 309 transmits information indicating this type to the radio base station 200 via the control line 205. The information indicating the type of the modulation / demodulation device may be detected by the wireless base station at the time of relay instead of being notified from the mobile communication switching center to the wireless base station.

When the mobile communication switching control circuit 309 receives the information indicating the type of the modulation / demodulation device from the mobile device 100 via the radio base station 200, it selects either the adapter device ADP310 or ADP311 as described above. To do. In this processing, by controlling the switch circuit 301a, the communication line from the radio base station 200 is connected to the designated incoming line of the adapter device ADP310 or 311 and the switch circuit 301b is controlled to control the adapter device. This is done by connecting the outgoing line of the and the public communication network. As a result, the same type as the modulation / demodulation device 503 used by the data terminal 502 is selected also in the mobile communication switching center 300, and end-to-end communication can be performed between the data terminal 102 and the data terminal 502. .

On the other hand, when the mobile device 100 makes a call, the telephone 10
When the communication by 1 is designated, the mobile communication switching control circuit 309 controls the switch circuits 301a and 301b to connect the communication line from the wireless base station 200 and the incoming of the voice signal control unit 312 with. The outgoing line of the voice signal control unit 312 is connected to the public communication network.

Next, the data terminal 502 on the telephone network 400 side.
A case in which an incoming call arrives at the mobile device 100 from will be described. When the mobile device 100 having the automatic incoming call function has an incoming call to the mobile device 100 when either the telephone or the data terminal 102 is set by the switching circuit 109, the incoming call is received between the mobile device 100 and the mobile switching center 300. Although the control is performed, the mobile device 100 transmits the incoming call response signal including the information indicating the set communication type. After that, the operation based on this communication type information is performed, but this operation is exactly the same as the case of the above-mentioned mobile station call connection.

C: Modification (1) When a wireless line is used, a 64 kbps digital line is time-divided into, for example, 9.6 kbps × 6 channels, and 6 lines at the connection point with the analog telephone network are used. A method of terminating the analog data modem can be considered. When this is applied to the first embodiment, the wireless line DL 'may be replaced with a digital line of 64 kbps. Further, in actual use, the total communication charge can be reduced by transmitting a long distance with a digital leased line of 64 kbps and making a local connection with an analog telephone network.

(2) Further, in each of the above-mentioned embodiments, the digital line is a wireless line, but it may be a wired line.

(3) Further, in the in-communication command mode in the above-described embodiment, the command requesting the command list is accepted, but it goes without saying that another command can be executed. That is, after shifting to the in-communication command mode, the analog data modem 6 is in a state of executing the supplied command, and therefore accepts all commands other than the unexecutable command. Here, a case of accepting a command to disconnect the communication line will be described. First, FIG. 13 shows a sequence up to the disconnection of communication of a general modem, and shows processing in the system shown in FIG. In FIG. 13, the escape instruction 31 is the analog data modem M.
When supplied to OD10, analog data modem MOD
10 returns the response signal 33 to the terminal device DTE1 and switches from the transparent mode to the communication command mode.

Then, in the command mode during communication,
The command "ATH0" for disconnecting the communication line is the terminal device D.
When supplied from TE1, this command is accepted by the analog data modem MOD10, the communication line is disconnected (on-hook), and the "NO CARRIER" signal is transferred to the terminal device DTE1.

Next, the processing of the present invention corresponding to the processing of FIG. 13 will be described with reference to FIG. Note that this process is a process executed in the system shown in FIG. First, as shown in FIG. 14, the escape instruction 31 is sent from the terminal device DET1 to the adapter device ADP10, transferred to the modem control command analysis unit 52, and analyzed. When the modem control command analysis section 52 decodes the escape instruction 31, it causes the digital line communication protocol control section 2 to issue an escape notification D. That is, as shown in FIG. 14, the digital line communication protocol control unit 52 transmits the notification D indicating that the escape command has been received, using the digital line communication protocol. This notification D is for the digital mobile device M.
S is transferred to the digital radio base station BS,
It is input to the communication protocol control unit 5 for digital line. The digital line communication protocol control unit 5 reproduces the escape command 31 and supplies it to the analog data modem 6 via the interface unit 61. As a result, the analog data modem 6 transmits a response signal (“OK”) 32 indicating that the reception has been confirmed to the digital line communication protocol control unit 5 and shifts to the command mode. The response signal 32 is converted into a response notification E in the communication protocol control section 5 for digital lines (see FIG. 14), and is transmitted from the digital radio base station BS according to the protocol for digital lines. Then, the response notice E is received by the digital mobile unit MS and transferred to the digital line communication protocol control unit 2. And
The response notification E is demodulated as the response signal 33 and supplied to the terminal device DTE1 via the modem control command analysis unit 52. As a result, the terminal device DTE1 knows that the analog data modem 6 has accepted the escape command.

In this way, when the terminal device DTE1 outputs the command "ATH0" for instructing the line disconnection after shifting to the in-communication command mode, the modem control command analysis unit 52 analyzes this and controls it. It is transmitted to the part 53. As a result, the control unit 57 outputs a control signal for disconnecting the communication to the control line 57. This control signal is transmitted via the digital mobile unit MS and the digital radio base station BS, and is further supplied to the control unit 63 via the control line 58. Then, the control unit 63 outputs a control signal for disconnecting communication to the analog telephone line network SL, whereby the line of the analog data modem MOD20 is disconnected. Since the command "ATH0" is completed by being processed by the modem control command analysis unit 52, it is not transferred to the analog data modem 6 side. On the other hand, the modem control command analysis unit 52 transmits a "NO CARRIER" signal to the terminal device DTE1 to notify that the line is disconnected.

[0065]

As described above, according to the present invention, the line between the terminal device and the analog data modem, which are set to communicate via the digital line, is not connected. At any time, the operation settings of the analog data modem can be set (claim 1
6).

Further, in the inventions according to claims 2 and 5, even when the system is in the data transfer state, the operation mode of the analog data modem can be surely switched and various commands can be sent to the modem. Can be executed.

Further, in the inventions according to claims 3 and 6, even when the system is in the data transfer state, the operation mode of the analog data modem is surely switched and the command set in the modem is known. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a sequence diagram showing an operation of the embodiment.

FIG. 3 is a flowchart corresponding to the sequence shown in FIG.

FIG. 4 is a sequence diagram showing a mode switching operation in the same embodiment.

FIG. 5 is a flowchart corresponding to the sequence shown in FIG.

FIG. 6 is a flowchart showing escape sequence determination processing shown in FIG.

FIG. 7 is a diagram showing an example of an escape instruction.

FIG. 8 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 9 is a block diagram showing an example of a conventional data transmission system.

FIG. 10 is a sequence diagram showing processing from a standby state to a data transfer mode in a general modem.

FIG. 11 is a sequence diagram showing a mode switching operation in a general modem.

FIG. 12 is a block diagram showing another example of a conventional device.

FIG. 13 is a sequence diagram showing execution of a command to disconnect the line in the conventional system.

14 is a sequence diagram showing execution of a command for disconnecting a line in the system shown in FIG.

[Explanation of symbols]

2 Digital line communication protocol control unit (second digital line control unit: command transfer means: control unit) 5 Digital line communication protocol control unit (first digital line control unit) 6 Analog data modem (modem unit) 51 Modem control command memory (command storage means) 52 Modem control command analysis section (modem mimicking means: processing mimicking means) 53 Controlling section (call request control means) 400 Telephone network (analog transmission line) SL Analog telephone line network (analog transmission) Line) SL 'digital wireless line (digital transmission line) ADP10 adapter device (first data relay device) MS digital mobile unit (first data relay device) ADP20 adapter device (second data relay device) MOD analog data modem

Claims (6)

[Claims] 1. A first analog-digital mutual conversion converter provided between an analog transmission line and a digital transmission line.
Data relay device and a second data relay device provided on the other end side of the digital transmission path, and the first and second data relay devices are configured to perform incoming / outgoing call control. In the transmission system, the first data relay device includes: (a) a modem unit that sends and receives data to and from an analog data modem connected to the other end of the analog transmission path according to an analog communication protocol; A first digital line control unit for transmitting the data transferred from the modem unit to the digital transmission line according to the digital communication protocol and transferring the data received from the digital transmission line according to the digital communication protocol to the modem unit. And the second data relay device includes (a) a device supplied from an external terminal device. When digital data is an operation setting command for setting the operation state of the modem unit, a modem mimicking unit that imitates a processing procedure in the modem unit and responds to the terminal device; and (b) imitation of the modem mimicking unit. Command storage means for storing a target operation setting command, and (c) the first device according to a command from the terminal device after the imitation by the modem imitation means is completed.
Call request control means for making a call request to the data relay device, and (d) the command stored in the command storage unit after the incoming call corresponding to the call request is made. Command transfer means for transferring to the modem section of the device, and (e) sending data other than the command transferred from the terminal device to the digital transmission line according to the digital communication protocol, and from the digital transmission line to the digital communication protocol. A second digital line control unit for transferring the data received according to the second digital line control unit to the terminal device, and the analog data modem unit is connected to the analog transmission line when the command transfer by the command transfer unit is performed. The feature is that the above analog data modem is negotiated to shift to the data transfer mode. Data transmission system to be. 2. In the data transfer mode, when the digital data supplied from an external terminal device is a command indicating a mode in which the command should be responded,
A control unit for converting the command into predetermined code information and sending it to the second digital line control unit, and the modem unit when digital data supplied from an external terminal device is a command for the modem unit. And a command processing mimicking means for terminating this processing by responding to the terminal device by imitating the processing procedure in the above, and the command processing mimicking means sends the code sent by the second digital line control unit. 2. The data transmission system according to claim 1, wherein the information is reproduced into a command by the first digital line control unit, and is operated after the command is accepted by the modem unit. 3. The command processing imitating means imitates a processing procedure in the modem section when the digital data supplied from an external terminal device is a command requesting a list of setting commands. 3. The data transmission system according to claim 2, wherein the list of commands in the above is returned to the terminal device and the processing is terminated. 4. A first analog-to-digital mutual conversion provided between an analog transmission line and a digital transmission line.
And a second data relay device provided on the other end side of the digital transmission path, and the first and second data relay devices are configured to control incoming and outgoing calls. The first data relay device includes (a) a modem unit for transmitting and receiving data to and from an analog data modem connected to the other end of the analog transmission line in accordance with an analog communication protocol, and (b) the modem unit. A first digital line control unit for transmitting the transferred data to the digital transmission line in accordance with the digital communication protocol and transferring the data received from the digital transmission line in accordance with the digital communication protocol to the modem unit. The second data relay device (a) digitizes data other than the command transferred from the terminal device. In a data transmission system having a second digital line control unit for transmitting to the terminal device the data received from the digital transmission line according to the digital communication protocol in accordance with the communication protocol for communication, ) When the digital data supplied from the external terminal device is an operation setting command for setting the operation state of the modem section,
A first step of responding to the terminal device by imitating the processing procedure in the modem section; and (b) a second step of storing in the storage means the operation setting command that is imitated by the imitating means in the first step. And (c) a third step of making a call request to the first data relay device in response to a command from the terminal device after the first step is completed, and (d) the call A fourth step of transferring the command stored in the storage means to the analog data modem section of the first data relay device after an incoming call corresponding to the call request is made.
And (e) after the completion of the fourth step, perform a negotiation between the destination analog data modem connected to the analog transmission line and the modem section to shift to the data transfer mode. Data transmission method characterized by. 5. In the data transfer mode, when the digital data supplied from an external terminal device is a command indicating a mode in which the command should be responded,
A code information sending step of converting the command into predetermined code information and sending it to the second digital line control unit, and the code information sent by the second digital line control unit to the first digital line control unit. A reproducing step of reproducing a command by a section, and when the command reproduced by the reproducing step is received by the modem section and digital data supplied from an external terminal device is a command for the modem section, 5. A command mimicking process which responds to the terminal device by imitating the processing procedure in the modem section and terminates this processing.
Described data transmission method. 6. In the command mimicking process, if the digital data supplied from an external terminal device is a command requesting a list of setting commands, the processing procedure in the modem section is imitated in the command storing means. Returns a list of commands to the terminal, and
The data transmission method according to claim 5, wherein the processing is terminated.