JPH04119744A - Terminal adapter for digital communication line - Google Patents

Abstract

PURPOSE:To attain data communication through the use of an economical and efficient exchange without notice of it by the user by selecting properly a line exchange and a packet exchange network depending on a time zone automatically. CONSTITUTION:A packet exchange changeover time is read from a packet exchange changeover time storage area 25a in a memory 25 by a CPU 29 and the time is compared with a current time obtained from a clock section 23, and when the current time is within the packet exchange changeover time, a packet exchange network is selected. When the current time is at the outside of the range of the packet exchange changeover time, the CPU 29 reads the line exchange changeover time in a line exchange changeover time storage area 25b in the memory 25 and compares it with the current time obtained from the clock section 23, and when the current time is within the range of the line exchange changeover time, the CPU 25 selects the line exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a terminal adapter used in connection with an integrated service digital network.

(Prior Art) In recent years, with the advancement of communication technology and the diversification of communication forms, various communication network systems have been developed.
egrated 5erv1ces dlgital
network). This l5DN provides telephone, data, facsimile communication, and various communication processing services in a digital communication line.
A communication system using N is configured as shown in FIG. 4, for example.

That is, this system has a digital communication line exchange 14 to which a digital line switching network 11, a packet switching network 12, a common line signal network 13, etc. are connected, and the subscriber! The I9 is connected to a network termination device 8 in the user's home, and the network termination device 8 is connected to the home bus 10 in the user's home, and the home bus 10 is equipped with telephone devices, facsimile devices, voice mail devices, printing devices, etc.
A communication terminal device 6 such as a personal computer is connected. Then, a plurality of communication channels are selectively used for each subscriber line 9 to perform desired communication between communication terminal devices.

For example, a basic interface with a transmission rate of 192 bits/second has two B channels of 64 bits/second and one
time-division multiplexing of 6 kbit/s D channels,
These channels are used to transmit data, etc.

There is a terminal adapter device called a terminal adapter (TA) as a terminal connected to the home bus 10 in a line like 2. This TA is used to replace existing communication terminal equipment that does not have a signal conversion function called the D channel protocol, which is a protocol for the 15DN user/network interface.
This is an adapter that allows you to connect to and use a 5DN line, and is equipped with multiple existing terminal interfaces.
One of these existing terminal interfaces can be used to connect an existing terminal connected to that existing terminal interface by converting one channel of the 15DN line and sending and receiving signals.
This allows it to be connected to a 5DN line and used for communication.

The basic interface of l5ON allows up to 8 communication terminals to be connected to the home bus, and in addition to the subscriber telephone number for that line, these terminals are connected by adding a sub-address for each terminal set by the user. By calling, it is possible to have the call arrive at the communication terminal specified by the subaddress.

FIG. 5 is a block diagram showing an example of the configuration of a conventional terminal adapter. In the figure, 1 is the terminal adapter body, 2 is a CPU (processor), 3 is an existing terminal interface, 4 is an 15DN line interface, and 5 is a memory. , 6 is an existing terminal, 7 is a printing device, 8 is a network termination device, and 9 is a digital subscriber line.

In the case of a basic interface, the digital subscriber line 9 is composed of two 84 kbps B channels and one 16 kbps D channel.

Existing terminal interface 3 is connected to the CPIJ bus,
It sends and receives data to and from existing terminals. For example, if the existing terminal has an R5232C standard interface as a communication interface, this existing terminal interface 3 may be the well-known USART (Universa
l 5ynchronus/Asynchronous
Receiver Transmitter:Inte
It is composed of integrated circuit elements such as 8251A from one company,
In the case of a printer, it is constructed from integrated circuit elements such as the well-known PIO (peripheral input/output circuit).

l5DN line interface 4 is USART and l5DN
It consists of 5 ICs (5-point interface; 8 points refer to service access points). This SIC is, for example, a circuit element that includes a parallel port and two 64 kbps serial ports, and uses the parallel port to send and receive D channel signals, and the serial port to send and receive B channel signals.

When making a call to the 15DN, the CPU 2 writes necessary data (telephone number, etc.) to the parallel port (Dch) of the SIC. When sending data from an existing terminal to the line, write the data to [l5ART, LISAl? T to S
Sent to the IC's serial port.

The memory 5 includes a data buffer for transmitting and receiving data, and a C
Execution programs etc. of PU 2 are stored, and the CPU
2 is in charge of controlling the entire system. Also, C
When the PU 2 receives a call from a terminal, it waits for dial input information from that terminal, and when it receives the dial input information, it sends it to the subscriber line 9, which is a central office line, via the ISDN line interface 4, and connects it to the 15DN network. send to When a call is received from the 15DN network via ISDN line interface 4,
If there is a sub-address, the CPU 2 processes the call so that it will arrive at an existing terminal corresponding to the sub-address, and if there is no sub-address, it processes the call in accordance with each existing terminal and allows the call to arrive at each existing terminal. perform the action.

In this way, the terminal adapter 1 described above performs normal IS communication between an existing terminal connected to its built-in existing terminal interface and a partner terminal connected to the 15DN network.
It is possible to perform communication based on the DN system. In addition, some terminal adapters 1 are built into existing terminals, thereby making it possible to use existing terminals that are not for ISDN as terminals for I5DN. In any case, this terminal adapter is inserted between an existing terminal and the Integrated Services Digital Network (ISDN), and by converting the interface between the terminal and the ISDN, it becomes possible to exchange data between the terminal and the ISDN. It is something to do.

By the way, in the 15DN, it is possible for the communication terminal device to select, for example, either a circuit switching network or a packet switching network, and data is transmitted from the communication terminal device through the selected switching network. be able to. In the circuit switched network, charges are made according to communication time, so it is more economical to select this switched network when a large amount of data is to be communicated in a short period of time. On the other hand, packet-switched networks charge fees according to the amount of data transmitted.
When communicating a small amount of data, it is more economical to select this packet switching network.

Here, call control procedures for circuit switching and packet switching will be described.

To begin with, circuit-switched call control is performed on the D channel, and when a calling user sets up a call to the network, the network accepts the call setting for the calling user, and also requests the called user to set up the call. When a response is received from the called user, the network returns the response to the calling user, thereby enabling communication.

Then, when the line is disconnected, steps are taken to release the line and terminate communication.

On the other hand, in packet switching, the B channel packet procedure and the D channel packet procedure are used.
There is a channel packet procedure, and in the B channel packet procedure, the B channel is first
A channel is set, and then communication is performed using a B channel according to a predetermined packet communication procedure (link level, packet level). In addition, in the D channel packet procedure, after the link is established by layer 2, a predetermined packet level
Packet communication is performed using the protocol.

Packet communication requires a device for assembling and disassembling packets, but even if this is provided, the call control described above is required to enable the selection of either circuit switching or packet switching. Requires a change in procedure.

Therefore, it is complicated for the user to select between the circuit switching network and the packet switching network at any given time, and errors are inevitable, leading to confusion.

Terminal adapters are often used to connect terminals such as personal computers installed at various locations to a central host computer using an I5DN. However, in such cases, since the user is not an expert in L5DN, it is difficult to perform the task of switching to the desired network that is considered optimal between the circuit switching network and the packet switching network depending on the amount of data. Of course.

Therefore, even if 15DN is used, efficient data communication cannot be performed because the terminal is set to fixed line switching when installed.

(Problems to be Solved by the Invention) As described above, in the I5DN, it is possible for the communication terminal device to select either the circuit switching network or the packet switching network, and the selected Data can be transmitted from the communication terminal through a switched network. Circuit-switched networks charge according to the communication time, so they are advantageous when transmitting large amounts of data in a short period of time, while packet-switched networks charge according to the amount of data transmitted, so they are advantageous when transmitting small amounts of data. This is advantageous when

Therefore, it is economical to select the network to be used depending on the amount of data, but in order to be able to select between circuit switching and packet switching, it is necessary to switch call control procedures according to each. .

This switching is too complicated and confusing to leave to general users, so in the past, for the convenience of general users, when installing a terminal, the network to be used was either circuit-switched or packet-switched. Since the setting is fixed to one side, there is a problem that efficient data communication cannot be performed.

In other words, it is not possible to choose a circuit-switched network when the amount of communication data is large, and a packet-switched network when the amount of communication data is small, so you are forced to use uneconomical communication, and it is not rational. Not on point.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a terminal adapter that allows switching networks easily and selects and uses efficient data communication.

Our goal is to provide the following.

[Configuration of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. In other words, in a terminal adapter that transmits and receives signals by interposing a circuit-switched network and a packet-switched network between a digital communication line that can be used and a communication terminal, a digital communication line that connects to a digital communication line and transmits and receives signals. an interface, a clock means for generating time information, assembling transmission data obtained from the communication terminal into a packet for packet transmission, providing it as a transmission output to the digital communication line interface, and obtaining the data via the digital communication line interface. a packet disassembly and assembling means for disassembling received packets and extracting them as data for the communication terminal; and a packet disassembly and assembly means for disassembling received packets and extracting them as data for the communication terminal; and outputting transmission data from the communication terminal in accordance with regulations for a circuit switched network and outputting the data to the digital communication line interface as a transmission output. a converting means for line switching which converts the received signal obtained from the digital communication line interface into data for the communication terminal and obtains the received data as received data, and the time information obtained from the clock means and a preset packet switching network. The packet switching switching time information indicating the transition to the circuit switching network and the circuit switching switching time information indicating the transition to the circuit switching network are compared, and the switching network to be used is determined. The converting means for circuit switching is controlled to be operable during the usage period of the circuit switching network.

(Function) This device with such a configuration is used by being interposed between a digital communication line and a communication terminal, but the digital communication line can use a circuit switching network or a packet switching network, and the communication terminal When the terminal is a data terminal, it is best to select and use the most suitable one of the above two switching networks with different billing systems depending on the amount of data to be exchanged. In this device, the clock means generates time information, and the control means uses the time information obtained from the clock means, packet switching switching time information indicating transition to a preset packet switching network, and line information indicating transition to a circuit switching network. The switch switching time information is compared with that to determine the switching network to be used, and the packet disassembling and reassembling means is controlled to be operable during the usage period of the packet switching network, and the circuit switching converting means is operated during the usage period of the circuit switching network. control to enable operation.

As a result, the data transmitted from the communication terminal to the digital communication line is input to the operable one of the packet disassembly and assembly means and the circuit switching conversion means, and is processed before being transferred to the digital communication line via the digital communication line interface. sent to the communication line. Therefore, if the packet disassembly/assembly means is operational, the packet switching network is used, and if the circuit switching conversion means is operational, the circuit switching network is used. Data will be transmitted.

Therefore, in a communication terminal device connected to a digital communication line such as 15DN via a terminal adapter, it is possible to automatically select one of multiple types of switching networks depending on the time, and this automatic selection is possible. Data can be sent and received through a switched network.

In data communication on data terminals such as computers, there is often a correlation between the time of day and the amount of data communication, with the amount of data being generally high during the day and being low at night. If the characteristics are clear, this characteristic can be used to automatically select the appropriate circuit-switched network or packet-switched network depending on the time of day, allowing users to perform efficient data communication without being aware of it. becomes possible.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a terminal adapter according to the present invention, and shows a personal computer (hereinafter referred to as a personal computer) as an existing terminal and an l5D.
This shows an example in which this terminal adapter 20, which serves as an interface between N12, is inserted.

The terminal adapter 20 includes a serial input/output unit 24 that exchanges serial data with the personal computer 31, a memory 25 that temporarily holds data exchanged via the serial input/output unit 24, and timer time information, and a line exchange. A V,120 circuit 26 that performs framing in accordance with the "V,120" procedure recommended by the CCITT (International Telegraph and Telephone Consultative Committee) used when communicating using a packet-switched network, and a packet data disassembly and assembling unit 27 that disassembles the received packet to extract necessary data and assembles the transmitted data into a predetermined packet;
5DN 22, a processor (hereinafter referred to as CPU) 29 that centrally controls the terminal adapter 20, and a clock section 23 that generates time information. The 8-point interface 28 is similar to the ISDN line interface 4 described in the prior art section.

When such a terminal adapter 20 communicates through a circuit-switched network, the V.120 circuit 26 inputs data to be transmitted and performs CC control on this data.
Framing is performed in accordance with the ITT Recommendation V.120 procedure, and the processed data is transferred to the 8-point interface 28.
It is sent to l5DN22 via.

In addition, when the data received from the 15DN 22 via the 8-point interface 28 is input to the V,120 circuit 26, the data is processed in the opposite manner to the previous processing, and the data obtained thereby is sent to the serial input/output section. 24 to the personal computer 21.

On the other hand, when communicating through a packet switching network, the packet data disassembly and assembly unit 27 receives data to be transmitted, assembles this data into packet data, and sends the assembled packet data to the l5DN 32 via the 8-point interface 28. Send to.

Further, the packet data disassembly and assembly section 27 sends the data obtained from the 1sDN 22 via the 8-point interface 28 to the personal computer 31 via the serial input/output section 24.

The clock unit 23 counts the time and reports the current time in response to a command from the CPU 29. This terminal adapter 2
0 has an exchange network switching timer function and an exchange network selection function. The exchange network switching timer function is realized by the CPU 29, memory 25, and clock section 23. The timer settings and the initial settings of the clock section 23 are performed by sending specific commands from the personal computer 31 via the serial input/output section 24. Further, these settings may be made by manually inputting an input section and a display section for the CPU 29 by separately providing the input section and display section.

The switching network selection function is realized by the CPU 29 and the memory 25. Then, to enable switching network selection, V, 1
20 circuit 26 and packet data disassembly and assembly section 27 are CPU
According to instructions from 29, when one is in an active state, the other is placed in an inactive state.

The CPU 29 compares the current time obtained from the clock unit 23 with the packet switching switching time data and line switching switching time data set in the memory 25, and determines if the current time is within the packet switching switching time. performs packet switching switching, and when the current time is within the circuit switching switching time, activates the switching network selection function to perform circuit switching switching. This is the switched network switching timer function.

Further, the switching network selection function is a switching control function provided to the CPU 29, and the packet switching switching is performed by the CPU 29 enabling the packet data disassembly and assembly section 27 to operate.V, 120
The circuit 26 is made inactive, and the CPU 29 makes the packet data disassembly and assembly section 27 inactive for line switching switching.V, 1
This is done by enabling the 20 circuit 26 to operate.

By storing a program etc. that implements such processing in the memory 25 and having it executed by the CPU 29, the terminal adapter is provided with a switched network switching timer function and a switched network selection function, and communication between the connected terminal and the 15DN is performed. is possible.

FIG. 2 is a memory map within the memory 25.

25a is a packet switching switching time storage area, and after this time, communication is performed via the packet switching network.

Reference numeral 25b is a circuit switching switching time storage area, and communication is thereafter performed using the circuit switching network. The received data storage area 25c stores data from the personal computer 21. 25d is a transmission data storage area, which is used to store data to be sent to the personal computer 21.

In addition, there is a processing program area 25e for an exchange network switching timer function and an exchange network selection function.

The operation of this device having such a configuration will be explained.

To explain the switching network selection function in this device, as shown in the flowchart of FIG.
reads the current time from the clock section 23 (STI). and,
The CPU 29 reads the packet exchange switching time from the packet exchange switching time storage area 25a in the memory 25,
This is compared with the current time obtained from the clock section 23 (Sr2
), if it is within the packet switching switching time range, the packet switching network is selected (Sr3). As a result, the packet disassembly/assembly section 27 becomes active from the next communication, and communication via the packet disassembly/assembly section 27 becomes possible.

As a result of the comparison in Sr2, if it is outside the range of the packet switching switching time, the process moves to step ST4, and the CPU 29 reads out the line switching switching time stored in the line switching switching time storage area 25b in the memory 25, and compares this with the clock section. The current time obtained from step 23 is compared, and if it is within the line switching switching time range, line switching is selected (Sr1). As a result, the V,120 circuit 26 is made active from the next communication, and communication via the circuit switching network is enabled using the V,120 circuit 26.

When transmitting data from the personal computer 31, when the data is received from the personal computer 31 via the serial input/output section 24, the CPU 29 temporarily stores it in the transmission data storage area 25d in the memory 25, and then transmits the data via the data bus. V, 120 circuit 26 and packet disassembly/assembly unit 27, but since only one of these is active depending on the time, it is taken into the active state and formatted. 8-point interface 28 and 8-point interface 2
8 to l5DN32. This allows you to set in advance whether to use a packet-switched network or a circuit-switched network depending on the time of day, and automatically select either the packet-switched network or the circuit-switched network depending on the time of day when sending data. and then use it.

When receiving a call, it can be determined whether the call is received using a packet switching network or a circuit switching network based on the incoming call information from the network.
Based on this information, the PU 29 activates the necessary one of the V120 circuit 26 and the packet disassembly/assembly unit 27, restores the data, and stores the received data storage area 25c in the memory 25.
Once stored in the serial input/output section 24, it is read out and
and sends it to the computer 31.

In data communication for computers, etc., there is a correlation between the time of day and the amount of data communication, such that the amount of data communication is generally high during the day and low at night. By automatically selecting an appropriate circuit-switched network or packet-switched network depending on the time of day, efficient data communication can be easily performed.

As explained above, since the timer automatically switches between packet switching and line switching, efficient data communication can be easily performed. In data communication for computers, etc., there is a correlation between the time of day and the amount of data communication, with data communication being generally high during the day and low at night. automatically selects the appropriate circuit-switched network and packet-switched network. Therefore, it becomes possible to easily perform efficient data communication.

In this way, this device connects to a digital communication line using a terminal adapter that performs signal exchange by interposing a digital communication line such as 15DN that can use a circuit-switched network and a packet-switched network and a communication terminal. A digital communication line interface (8-point interface) for sending and receiving signals, a clock means for generating time information, assembling the transmission data obtained from the communication terminal into a packet for packet transmission, and transmitting and outputting it to the digital communication line interface. packet disassembly and assembly means (packet disassembly and assembly unit) which disassembles the received packets and extracts them as data for the communication terminal; A converter for line switching that outputs the signal in accordance with network regulations and provides it as a transmission output to the digital communication line interface, and converts the received signal obtained from the digital communication line interface into data for the communication terminal to obtain the received data. means (V, 120 circuits), time information obtained from the clock means, packet switching switching time information indicating transition to a preset packet switching network, and circuit switching switching time information indicating transition to a circuit switching network. The comparison is made to determine the switching network to be used, and the packet disassembling and reassembling means is controlled to be operational during the usage period of the packet switching network, and the circuit switching converting means is controlled to be operational during the usage period of the circuit switching network. It is configured to include a control means (CPU).

In such a configuration, the digital communication line is used by being interposed between the digital communication line and the communication terminal, but the digital communication line can use a circuit switching network and a packet switching network, and when the communication terminal is a data terminal. It is best to select and use the most suitable one of the above two exchange networks with different charging systems depending on the amount of data to be exchanged. In this device, the clock means generates time information, and the control means uses the time information obtained from the clock means, packet switching switching time information indicating transition to a preset packet switching network, and line information indicating transition to a circuit switching network. The switch switching time information is compared with that to determine the switching network to be used, and the packet disassembling and reassembling means is controlled to be operable during the usage period of the packet switching network, and the circuit switching converting means is operated during the usage period of the circuit switching network. It is intended to control the system so that it can be operated.

Therefore, the data transmitted from the communication terminal to the digital communication line is input to the operable one of the packet disassembly and assembly means and the line switching conversion means, and is processed before being transferred to the digital communication line via the digital communication line interface. If the packet disassembly/assembly means is operable, the packet switching network is used, or if the circuit switching conversion means is operable, it is sent to the line. This allows data to be transmitted using a switched network.

Therefore, in a communication terminal device connected to a digital communication line such as 15DN via a terminal adapter, one of multiple types of switching networks can be automatically selected depending on the time, and this automatically selected Data can be sent and received through a switching network. In data communication on data terminals such as computers, there is often a correlation between the time of day and the amount of data communication, with the amount of data being generally high during the day and being low at night. If the characteristics are clear, this characteristic can be used to automatically select the appropriate circuit-switched network or packet-switched network depending on the time of day, allowing users to perform efficient data communication without being aware of it. becomes possible.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope without changing the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, in a communication terminal device that is connected via a terminal adapter to a digital communication line such as an IS network that can utilize a circuit switching network and a packet switching network. , for users who have a correlation between the time of day and the amount of data traffic, this feature can be used to automatically select the appropriate circuit-switched network or packet-switched network depending on the time of day. It is possible to provide a terminal adapter for a digital communication line, which has the feature that data communication can be carried out unconsciously using an economically efficient switching network.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a memory map used in the device of the present invention, and FIG. 3 is a flowchart showing the main functions of the device of the present invention. , FIG. 4 is a diagram for explaining the conceptual system configuration of I5DN, and FIG. 5 is a block diagram for explaining an example of the configuration of a conventional terminal adapter. 11...Personal computer, 12...l5D
N. 20...Terminal adapter, 23...Clock part,
24... Serial input/output section, 25... Memory, 26
...V, 120 circuits, 27...Packet disassembly and assembly section, 28...8-point interface, 29...CPU
.

Claims (1)

[Scope of Claims] A terminal adapter for transmitting and receiving signals by interposing a circuit-switched network and a packet-switched network between a digital communication line and a communication terminal, and for transmitting and receiving signals by connecting to the digital communication line. a digital communication line interface, a clock means for generating time information, assembling the transmission data obtained from the communication terminal into a packet for packet transmission, giving it as a transmission output to the digital communication line interface, and using the digital communication line interface. packet disassembly and assembly means for disassembling received packets obtained through the communication terminal and extracting them as data for the communication terminal; and a packet disassembly and assembly means for disassembling the received packets obtained through the communication terminal and extracting them as data for the communication terminal; a converting means for line switching, which is provided as a transmission output to the digital communication line interface and converts the received signal obtained from the digital communication line interface into data for the communication terminal to obtain the received data; and time information obtained from the clock means and set in advance. Packet switching switching time information indicating transition to a packet switching network and circuit switching switching time information indicating transition to a circuit switching network are compared to determine the switching network to be used, and the packet switching time information indicating transition to a circuit switching network is determined. A terminal adapter for a digital communication line, comprising control means for operatively controlling a disassembly and assembling means, and operatively controlling the line switching converting means during a period of use of a line switching network.