JPH118713A - Isdn terminal adapter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize communication with a DTE connected to an existed telephone network without switching the connection of the cable of the DTE and a call with the telephone set of an ISDN network by connecting the ISDN network with the existed telephone network and an analog terminal and connecting the terminal equipment with the existed telephone network and the analog terminal. SOLUTION: A DTE control part 3 discriminates whether the terminal of a connection destination is the ISDN network or a PSTN network through the ISDN network or a private telephone network by a calling command, a calling operation is executed and an inner speed adjusting part 12 and a modulation/demodulation part 18 are switched. A means for discriminating whether an incoming call is from the ISDN network or from the private telephone network when there is a call-in. A means for discriminating whether the call-in from the ISDN network is data of a speed matching system or modulation/demodulation data from the PSDN network through the ISDN network is provided. Furthermore, a means for discriminating the call-in from the private network and the call-in from the telephone set connected to the ISDN network and making it call-in at an external telephone set through a telephone control part 26 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ISDN (lnt
Egrated Service Digital N
ISD with digital speed matching function, modulation / demodulation function, telephone network connection interface, and existing telephone connection interface
Related to N terminal adapter.

[0002]

2. Description of the Related Art Conventionally, a coding / decoding section of this type of ISDN terminal adapter is directly connected to a modulation / demodulation section.
DTE (Data Terminal Equipment)
nt) The signal switching unit is switched to the speed matching unit, and is connected to the DTE via the DTE interface.

[0003] As a prior art, Japanese Patent Laid-Open Publication No.
And 1 SDN disclosed in JP-A-5-22475
There is a terminal adapter. FIG. 4 is a block diagram showing the configuration of such a conventional ISDN terminal adapter with a built-in modem.

In FIG. 1, an ISDN network control unit 76
It is connected to the ISDN line 77 to perform outgoing / incoming call control on the ISDN exchange, determine the contents of an incoming call message sent at the time of incoming call from the network, and send B channel data to the speed matching unit 62, Alternatively, it is switched between sending to the encoding / decoding unit 70. Similarly, the DTE signal switching unit 56 switches between the signal passed to the DTE control unit 53 and the data from the speed matching unit 62 or the signal from the modulation / demodulation unit 67.

At the time of calling, the DTE control unit 53 analyzes the calling command from the DTE 51 to determine whether the connection destination terminal is of the speed matching type or is connected to the modem. And the B channel of the ISDN network control unit 76 is switched. Speed matching unit 6
2 is located between the DTE control unit 56 and the ISDN network control unit 76, and converts the low-rate data sent from the DTE 51 to a B-channel communication speed of 64 kbit / s of the ISDN network.
s. Also, 64 kbi from the ISDN network
The t / s high-speed reception data is converted to the DTE 51 low-rate data.

[0006] Modulation / demodulation section 67 and coding / decoding section 70
Is the existing public telephone network (Publ) via the ISDN network.
ic Switched Telephone Net
This is used when performing opposite communication with a terminal device connected to the work. The other party's terminal device has a built-in modulation / demodulation unit similar to this device. The low-speed transmission data from the DTE 51 is modulated in a modulation / demodulation unit and converted into a signal in a voice band. And 64 kb in the encoding / decoding unit
It is converted to an it / s PCM code and transmitted to the ISDN network.

On the other hand, when a PCM-coded modulation code is received from the ISDN network,
The PCM code of 4 kbit / s is decoded into a signal in a voice band, and further converted into low-rate data by a modulation / demodulation unit 67 and passed to the DTE 51. The device control unit 64 includes:
The part that controls the entire ISDN terminal adapter.
CPU (Central ProcessingUni)
t), RAM (Random Access Memory)
ry) and a ROM (Read Only Memory) in which a program for controlling this apparatus is written.

[0008]

The conventional ISDN terminal adapter has the following problems. That is, the first problem is that the modulation / demodulation unit is built in the device,
DTE connected to an existing public telephone network (PSTN) or a private telephone network (PBX) with a similar interface
When communicating with the DTE 51, a modem having a network control function is provided separately from this device, and a connection cable 52 of the DTE 51 is provided.
It is necessary to reconnect. The second problem is that, despite the fact that the present apparatus has an encoding / decoding unit 70, it cannot be received when a call is received from a telephone connected to the ISDN network. It is necessary to connect to 77.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to replace existing DTE connection cables without using an ISDN telephone, and to use existing ISDN telephones. An object of the present invention is to provide an ISDN terminal adapter capable of communicating with a DTE connected to a public telephone network or the like and receiving an incoming call from a telephone connected to an ISDN network.

[0010]

In order to solve the above-mentioned problems, the present invention provides a DTE control unit in which a connection destination terminal is an ISDN network or an ISD
In this system, a calling operation is performed by determining whether the network is a PSTN network via an N network or a private telephone network, and an internal speed matching unit and a modulation / demodulation unit are switched. In addition, at the time of an incoming call, there is provided means for determining whether the call is from the ISDN network or from the private telephone network. It has means for discriminating between data of the matching system and modulation / demodulation data from the PSDN network via the ISDN network. Also, incoming calls from the private telephone network, incoming calls from telephones connected to the ISDN network, and PST via the ISDN network.
It has a means for judging an incoming call from a telephone in the N-network and receiving an external telephone via a telephone control unit.
Therefore, by using the ISDN terminal adapter of the present invention including the analog signal switching unit, the telephone network control unit, and the telephone control unit between the modulation / demodulation unit and the encoding / decoding unit, the DTE cable connection change and the ISDN interface cable are performed. No need to change the connection.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an ISDN terminal adapter according to the present invention. In the figure, DTE (Data Terminal Equipment)
1) is a terminal device having an existing V-series or X-series serial interface. D
The TE 1 is connected to the DTE control unit 3 via the connection cable 2.

The DTE control section 3 converts TTL level transmission / reception data and control signals in the present apparatus to signal levels defined by the interface specifications in order to interface with the DTE 1. In addition, data transmission / reception control and OFF / ON of a control signal and OFF / ON of a control signal from a partner.
Monitor ON. The DTE signal switching unit 6 switches whether to connect the signal from the DTE 1 to the speed matching unit 12 or the modulation unit / demodulation unit 18. Here, the data received from the SDN line 35 is a DTE
The signal is passed from the signal switching unit 6 to the DTE control unit 3. Also, D
The transmission data 5 from the DTE 1 via the TE control unit 3 is passed to the DTE signal switching unit 6.

The speed matching unit 12 adjusts the communication speed of the existing DTE 1 to the communication speed of the B channel of the ISDN line, receives the low-speed transmission data 7 from the DTE signal switching unit 6, and sets the speed to 64 kbit / s. The speeds are matched and passed to the ISDN network control unit 34 as high-speed transmission data 29.

The data received from the ISDN is ISDN
Via the network control unit 34, the data enters the speed matching unit 12 as high-speed data 30. The speed matching unit 12 speed-matches the communication speed of the DTE 1 to the low-speed reception data 8.
It is passed to the DTE control unit 3 via the TE signal switching unit 6,
It is passed to DTE 1 via cable 2. The device control unit 14 controls the entire ISDN terminal adapter, and includes, for example, a microprocessor, a ROM (Re
ad 0nly Memory), RAM (Rando)
m Access Memory) and controls each functional block.

The ISDN network controller 34 has an ISDN line 35
In order to connect to the network, a physical interface of layer 1 is provided, and protocol control of layers 2 and 3 is performed. Further, a B channel that can be used as an ISDN data channel is switched. The B channel is connected to the speed matching unit 1
2 or the encoding / decoding unit 20 is switched.

The analog control section 37 is a section which is connected to the existing public telephone network and functions when communicating with the DTE via the modem. It is a public switched telephone network (PSTN) that is interconnected with an ISDN network.
HTE (TelephoneNetwork). The analog control unit 37 includes a modulation / demodulation unit 18, an analog signal switching unit 19, a coding / decoding unit 20,
It comprises a telephone network control unit 25 and a telephone control unit 26.

The modulation / demodulation unit 18 is used to transmit digital transmission data from the DTE 1 to an opposite party via a modem (hereinafter, referred to as a modem) connected to an existing public telephone network. The analog signal switching section 19 transmits the transmission data from the DTE 1 via the modulation / demodulation section 18 to the public telephone network (including the private telephone network 38) via the telephone network control section 25.
Or by converting the analog signal into a 64 kbit / s digital signal by the encoding / decoding
Switching to send to the network control unit 34 is performed.

The analog signal switching unit 19 is provided with an ISD
An analog signal obtained by converting the digital data received from the N-network control unit 34 by the encoding / decoding unit 20 into a telephone control unit 26
Through the DTE signal switching unit 6 and the DTE control unit 3 after being output to an external telephone 39 (including a facsimile) via the DTE, or converted into a low-speed digital signal via the modulation / demodulation unit 18. To send to DTE1. The DSU 36 is a line termination device having a function of terminating an ISDN line.

Now, the operation of the ISDN terminal adapter configured as described above will be described with reference to the calling operation flow of FIG. When the DTE 1 makes a call (in the case of “Y” in step S1), the DTE 1 sends a call command to the adapter. At this time, the DTE 1 sends information on which network is connected to the connection partner. Upon receiving the outgoing call command, the DTE control unit 3 analyzes the content of the command and determines which network to connect to (step S2).

Here, when the connection partner is not the PSTN,
That is, in the case of the ISDN network, the DTE control unit 3
The DTE signal switching unit 6 is switched to connect the DTE control unit 3 to the speed matching unit 12 (Step S3). Next, under the control of the device control unit 14 having received the information from the DTE control unit 3 via the DTE signal switching unit 6, the ISDN network control unit 34 switches to the speed matching unit 12 and issues a call based on the telephone number from the DTE 1. A call operation is performed (step S4). Then, it waits for a certain period of time until the other party answers (steps S5 and S6), and when the other party answers, it goes online (step S5).
7). When the online state is established, the DTE 1 can communicate with the opposing DTE via the ISDN network.

If the online communication is terminated and disconnected from the connection partner, or if a disconnection command is received from the DTE 1 ("Y" in step S8), I
The SDN network control unit 34 performs a disconnection process (step S
9). Subsequently, the DTE control unit 3 performs an end process with the DTE 1 under the control of the device control unit 14 (step S1).
0).

On the other hand, if the connection destination specified by the call command from DTE 1 is determined by DTE control unit 3, and the connection destination is PSTN (“Y” in step S 2), DTE control is performed. The unit 3 connects the DTE signal switching unit 6 to the modulation / demodulation unit 18 (Step S11),
Further, the DTE control unit 3 determines whether the other party is via ISDN or PSTN (step S12).

If the connection partner is via lSDN ("Y" in step S12), the DTE controller 3
The analog signal switching unit 19 is connected to the encoding / decoding unit 20 by the device control unit 14 having received the result of the determination through the DTE signal switching unit 6 (step S13). Next, under the control of the device control unit 14, the ISDN network control unit 34
The channel switching is connected to the encoding / decoding unit 20 to execute a calling process based on the telephone number of the other party specified by the calling command sent from the DTE 1 (step S4).

Then, a predetermined time is waited until the other party answers (steps S5 and S6).
An online state is established between E1 and the other party's connection destination to enable communication (step S7). After calling processing,
If the other party does not respond after waiting a certain time (step S6
Is “Y”), the ISDN network controller 34 performs a disconnection process (step S9). Further, the DTE signal switching unit 6 of the device control unit 14 controls the DTE
An end process is executed in the control unit 3 (step S1).
0). In addition, when the online communication is terminated and disconnected from the partner DTE, or when termination processing is performed in response to the termination of the communication of the DTE 1 ("Y" in step S8)
Also executes the disconnection process.

Next, the call command from DTE 1 is
When the control unit 3 determines that the connection destination is a PSTN network that does not pass through the ISDN network (in the case of "N" in step S12)
Switches the DTE signal switching unit 6 to the modulation / demodulation unit 18 and then switches the analog signal switching unit 19 to the telephone network control unit 25 under the control of the device control unit 14 (step S1).
4). Then, the analog signal switching unit 1 of the device control unit 14
9, the telephone network control unit 25 performs a calling process to the PSTN (step S15).

Here, a predetermined time is waited until the other party answers (steps S16 and S17). When the other party answers, the other party terminal and the DTE 1 are brought online (step S18). If the other terminal has not responded (in the case of “Y” in step S17), the telephone network control unit 25 performs a disconnection process (step S20), and then the DTE control unit under the control of the device control unit 14. The end process is performed in step 3 (step S10). On the other hand, also when the online communication is completed (in the case of “Y” in step S19), the disconnection process is similarly performed by the telephone network control unit 25 (step S20), and then the termination process is performed by the DTE control unit 3 (step S20) S10).
Thus, the ISDN terminal adapter is provided with an interface for connecting to the existing PSTN or private telephone network 38 and an interface for connecting to the existing telephone 39 in addition to the ISDN network. Allows the user to select which interface to use.

Next, the operation of the present adapter when receiving a call will be described with reference to FIG. When there is an incoming call (step S2
1) The device control unit 14 confirms and determines whether the incoming call is from the ISDN network by the ISDN network control unit 34 and the telephone network control unit 25 (step S22). Where ISDN
For an incoming call from the network, the ISDN network control unit 34 determines whether the other terminal is a terminal directly connected to the ISDN network or a terminal connected to an inter-network from the PSTN network (step S23).

If the incoming call is from a terminal directly accommodated in the ISDN network, the information is received from the ISDN network control unit 34 and the ISDN network control unit 34 is controlled by the device control unit 14 to perform speed matching. Connect to the unit 12 (step S2
4) Next, the speed matching unit 12 and the DTE signal switching unit 6 are connected (Step S25). Then, under the control of the device control unit 14, the DTE control unit 3 performs incoming call control (step S26), and notifies the DTE 1 that there is an incoming call. The DTE control unit 3 monitors whether the DTE 1 responds to the request for a predetermined time (step S2).
7, S28).

If the DTE 1 responds, it goes online with the partner terminal (step S29). Also, if DTE1 does not respond after waiting for a certain time,
Release processing is performed in the DTE control unit 3 (step S3).
1) Subsequently, a disconnection process is performed in the ISDN network control unit 34 under the control of the device control unit 14 (step S33).
At the end of online communication ("Y" in step S30)
), The same release processing and disconnection processing are performed.

Next, when the incoming call is not via the ISDN, that is, when the incoming call is from the private telephone network 38, the incoming call processing is first performed in the telephone network control unit 25 (step S34). ). Next, the telephone network control unit 25 and the analog signal switching unit 19 are connected under the control of the device control unit 14 having received the incoming call information via a path (not shown) (step S35). It is detected whether the terminal is a modem (modem) (step S36). If a signal from the modem is detected, the analog signal switching unit 19 and the modulation / demodulation unit 18 are connected under the control of the device control unit 14 having received the detection information (step S37). Part 18 and DTE
The signal switching unit 6 is connected (Step S38).

Subsequently, DT is controlled by the device control unit 14.
The E control unit 3 performs incoming call control and notifies the DTE 1 that there is an incoming call (step S26). here,
Wait for DTE1 to respond for a fixed time (step S2
7, S28), when the DTE1 response is received, the state is changed to the online state (step S29). If the DTE 1 does not respond, the DTE control unit 3 performs a release process (step S31), and then performs a disconnection process in the telephone network control unit 25 under the control of the device control unit 14 (step S39).

If the analog signal switching unit 19 cannot detect the modem signal from the partner terminal ("N" in step S36), the analog signal switching unit 19 is controlled by the telephone under the control of the device control unit 14. Connect to the unit 26 (step S40). Subsequently, under the control of the device control unit 14 via the analog signal switching unit 19, the telephone control unit 26 controls the incoming call to notify the externally connected telephone 39 of the incoming call (step S41). And phone 3
Wait until there is a response of 9 (step S42). If there is a response, the line is held (step S43), and a telephone call with the partner terminal by the telephone 39 can be made.

Next, the telephone control section 26 detects the on-hook of the externally connected telephone 39 (step S44). When the on-hook is detected, the telephone control section 26 performs a release process (step S45), and furthermore, the apparatus control section. Under the control of 14, the telephone network control unit 25 performs a disconnection process and ends (step S39). In addition, PS via ISDN
In the case of an incoming call from the TN network, first, the ISDN network control unit 3
In 4, the B channel is connected to the encoding / decoding unit 20 (step S46), and the above-described control processing after step S36 is similarly performed. As described above, when an incoming call is received, it is possible to determine whether to connect to the DTE 1 or to the telephone 39 based on the determination of the incoming call message and the detection of the modem signal.

[0034]

As described above, according to the present invention, I
It can communicate with the terminal adapter using the speed matching method connected to the SDN network, can communicate with the DTE with a built-in modem connected to the PSTN network via the ISDN network, and can be connected to the private telephone network. It can also communicate with the DTE with a built-in modulator / demodulator without cable connection and setting change. Further, it is possible to make a telephone call with a digital telephone connected to an ISDN network, a telephone connected to a PSTN network via an ISDN network, and a telephone connected to a private telephone network without changing the connection.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an ISDN terminal adapter according to the present invention.

FIG. 2 is a flowchart showing an operation of the adapter at the time of calling.

FIG. 3 is a flowchart showing an operation of the adapter when receiving a call;

FIG. 4 is a block diagram showing a configuration of a conventional ISDN terminal adapter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DTE, 3 ... DTE control part, 6 ... DTE signal switching part, 12 ... speed matching part, 14 ... Device control part, 18 ... Modulation / demodulation part, 19 ... Analog signal switching part, 20 ... Code / decoding part, 25: telephone network controller, 26: telephone controller, 34
... Analog network controller, 38 ... Private telephone network, 39 ... Telephone.

Claims (5)

[Claims] 1. A speed matching unit for matching a communication speed between a terminal device and an ISDN network, a terminal control unit for controlling the terminal device, and a terminal signal switch for switching a signal input / output to the terminal device. Unit, an ISDN network control unit for controlling the ISDN network, an encoding / decoding unit for encoding a signal to the ISDN network and decoding a signal from the ISDN network, and modulating a signal from the terminal device and the terminal device An ISDN terminal adapter for connecting the terminal device, which is a non-ISDN terminal, to an ISDN network, comprising: a modulation / demodulation unit for demodulating a signal to the ISDN network; An analog signal switching unit for switching signals; a telephone network control unit connected to the analog signal switching unit for controlling an existing telephone network different from the ISDN network; and an existing network connected to the analog signal switching unit. An analog terminal control unit for controlling an analog terminal, wherein connection between the ISDN network and an existing telephone network and an analog terminal, and connection between the terminal device and an existing telephone network and an analog terminal are enabled. ISDN terminal adapter. 2. The terminal control unit according to claim 1, wherein upon receiving a call command from the terminal device, the terminal control unit identifies a network in which a connection destination terminal is accommodated, performs a call operation, and outputs a signal from the terminal device. ISDN terminal adapter for switching a signal path for transmitting a signal to the identified network side. 3. The system according to claim 1, wherein the ISDN network control unit determines an incoming call message at the time of an incoming call and determines whether the data is to be sent to a speed matching unit or to a modulation / demodulation unit. ISDN terminal adapter. 4. The incoming call from an ISDN telephone set accommodated in an ISDN network and an incoming call from a telephone set accommodated in an existing telephone network via an ISDN network by the ISDN network control unit. Characterized in that the analog terminal receives a call when it is determined to be one of the following. 5. The method according to claim 1, wherein the presence or absence of a modem signal is detected when a call is received from an existing telephone network,
An ISDN terminal adapter for receiving a call to one of a terminal device and an analog terminal.