KR100351735B1 - Private branch exchange apparatus using a data line of a public network and interfacing apparatus therefor - Google Patents

Abstract

The present invention implements a private switching device and a matching device therefor for providing a service of a digital private switch to a remote digital telephone subscriber using a data leased line of a public network. The apparatus of the present invention is matched between a private exchange, a public network, first and second digital service units connected to a data dedicated line of the public network, a digital subscriber line of the private exchange and the first digital service unit, Transceiving a digital line signal including a voice signal with a digital subscriber line of the private exchange and transmitting and receiving framed data having a predetermined structure with the first digital service unit and converting between the digital line signal and the framed data. A first matching means for performing a matching operation between the digital telephone of the remote digital telephone subscriber and the second digital service unit to transmit and receive the digital telephone signal to and from the digital telephone, and to the second digital service unit and the framed data. Transmitting and receiving the digital line signal and the data And second matching means for performing the conversion between the data.

Description

Private exchange device using data line of public network and matching device therefor {PRIVATE BRANCH EXCHANGE APPARATUS USING A DATA LINE OF A PUBLIC NETWORK AND INTERFACING APPARATUS THEREFOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital communication systems, and more particularly, to a private switching device and a matching device for providing a digital private switching service to a remote digital telephone subscriber using a data leased line of a public network.

In general, a private exchange device is a device that provides subscribers with various private exchange services in addition to the basic function of allowing a telephone subscriber within a certain area such as a company or a school to communicate only through a private exchange without a telephone station. For example, the private switching device provides a function for enabling a telephone call using only an extension number shorter than the original telephone number. The service provided by such a private exchange device is limited to a telephone connected to a private exchange within a certain area. However, in the case of analog phones, the connection method such as matching of analog phones and private exchange periods and signal standards is standardized. Even remote subscribers located in areas not directly connected to a private exchange could provide private exchange services via the telephone company's voice level transmission equipment.

On the other hand, digital phones, which can provide better quality calls and various services than analog phones, are increasingly used.

However, in the case of such a digital telephone, the connection method between the digital telephone and the private switching period is not standardized, unlike the analog telephone, so that the remote subscriber cannot be accommodated through the voice or data transmission equipment of the telephone station.

For example, a digital subscriber line of a private exchange and a digital telephone are connected at high speed using a time compression multiplexing (TCM) scheme, which has a solid line connection distance of about 1 km that can be used between the private exchange and a digital telephone. In addition, the connection between the private exchange and the digital telephone is not standardized. Thus, there has been a disadvantage that remote subscribers such as telecommuters located far away from the private exchange via the voice or data transmission equipment of the telephone station cannot use various functions provided by the private switching device.

It is therefore an object of the present invention to provide a private switching device and a matching device therefor, which are implemented to provide a digital private switching service to a remote digital telephone subscriber using a data leased line of a public network.

The purpose of the present invention is to implement a private switching device that can provide digital private switching services to remote digital telephone subscribers by matching the connection method of digital telephone subscriber lines accommodated by private exchanges to 64 Kbps data dedicated lines of telephone stations. Can be achieved.

In order to achieve the above object, the present invention provides a private exchange device for providing a digital private exchange service to a remote digital telephone subscriber,

With a private exchange,

Public Network,

First and second digital service units connected to a data dedicated line of the public network;

A digital line signal that is matched between the digital subscriber line of the private exchange and the first digital service unit, transmits and receives a digital line signal including a voice signal with the digital subscriber line of the private exchange, and transmits the framed data having a predetermined structure. First matching means for transmitting and receiving with a digital service unit and performing conversion between the digital line signal and the framed data;

Matched between the digital telephone of the remote digital telephone subscriber and the second digital service unit to transmit and receive the digital line signal to and from the digital telephone, and to transmit and receive the framed data to and from the second digital service unit; Provided is a private exchange device comprising second matching means for performing conversion between data.

1 is a block diagram showing a private exchange device according to the present invention;

FIG. 2 is a block diagram showing details of the exchange side and remote subscriber side matching devices of FIG. 1; FIG.

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

1: Switchboard side digital telephone

2: private exchange (PBX)

3, 9: exchange side and remote subscriber side matching device

4, 8: Exchange side and remote subscriber side digital service unit (DSU)

5, 7: data transmission device

6: public network

10: remote digital telephone

1 is a block diagram showing a digital private exchange device according to an embodiment of the present invention. One embodiment of the private switching device is a switch-side digital telephone 1, a private branch exchange (PBX) 2, a switch-side matching device 3, a switch-side digital service unit (DSU) ( 4), exchange side data transmission device 5, public network 6, remote subscriber side data transmission device 7, remote subscriber side DSU 8, remote subscriber side matching device 9, remote digital telephone 10 It includes.

In the embodiment of Fig. 1, only one switch-side digital telephone 1 and one remote digital telephone 10 are shown for example, but a digital telephone used by a plurality of subscribers may be connected to the digital private switching device. The switch-side digital telephone 1 and the remote digital telephone 10 are digital telephones such as key-phones, and the private exchange 2 uses the digital telephones 1 and 10 for various services, including the extension exchange service. A private switch having a digital subscriber line for providing a digital telephone subscriber.

The digital telephones 1 and 10 can be connected to the digital subscriber line of the private switch 2 using dedicated protocols and signal standards.

The digital subscriber line of the private exchange 2 is connected to the switch-side matching device 3, and the remote digital telephone 10 is connected to the remote subscriber-side matching device 9.

The switch-side matching device 3 is connected to the switch-side DSU 4 and the remote subscriber-side matching device 9 is connected to the remote subscriber-side DSU 8 at, for example, RS-232C at a transmission rate of 64 Kbps. do.

The DSUs 4 and 8 are connected to data transmission devices 5 and 7 of telephone stations (not shown) provided with data dedicated lines, and the data transmission speed is 64 Kbps.

The data transmission devices 5 and 7 provided in the telephone station (not shown) are connected to the public public network 6.

Referring to FIG. 1, an embodiment of providing a private exchange service via a public network 6 to a subscriber using the remote digital telephone 10 will be described in detail. Below, the private exchange (2) is Meridian 1 from Nortel Networks, and the digital subscriber line of the private exchange (2) sends data including voice and control signals to the Bipolar Return-to-Zero (BPRZ-AMI). Alternate Mark Inversion) transmits and receives a digital line signal coded at 512 Kbps.

The remote digital telephone 10 is a digital telephone used by a remote subscriber such as a teleworker located in an area that cannot be directly connected to the digital subscriber line of the private switch 2. The remote digital telephone 10 transmits / receives a digital line signal coded with a BPRZ-AMI scheme of voice and control signals with the remote subscriber side matching device 9 at a transmission rate of 512 Kbps.

The remote subscriber side matching device 9 converts the digital line signal received from the remote digital telephone 10 into framed data having a predetermined frame structure, and then uses the remote subscriber side DSU 8 in the RS-232C manner. To be sent). In addition, the remote subscriber side matching device 9 converts the framed data received from the remote subscriber side DSU 8 in the RS-232C manner into a digital line signal coded in the BPRZ-AMI manner to convert the remote digital telephone 10. To send. That is, the matching device 9 separates the voice signal and the control signal from the digital line signal received from the remote digital telephone 10, compresses the voice signal in a PCM manner, converts the voice signal into a PCM compressed voice signal, and controls the PCM compressed voice signal and control. The framed data including the signal is generated and then transmitted to the DSU 8. In addition, the matching device 9 separates the control signal and the PCM compressed voice signal from the framed data received from the DSU 8, and decompresses and reproduces the PCM compressed voice signal as a voice signal. It generates a digital line signal containing and transmits it to the remote digital telephone (10).

The matching device 9 and the DSU 8 are connected by RS-232C at a known transmission rate of 64 Kbps.

The remote subscriber side DSU (8) connects the framed data received from the remote subscriber side matching device (9) by RS-232C method with the data dedicated line terminal of the data transmission device (7) of the remote subscriber side telephone station, It transmits to the exchange side data transmission apparatus 5 via the public network 6 at the transmission speed. Further, the framed data received from the exchange side data transmission device 5 is transmitted to the remote subscriber side matching device 9 in RS-232C manner at a transmission rate of 64 Kbps. For example, synchronous data having a network mode of point-to-point continuous connection mode and a transmission rate of 64 Kbps is transmitted and received with the data transmission device 7 of the telephone station.

The switch-side DSU 4 is connected to the data-only line terminal of the switch-side data transmission device 5 to transfer the framed data received from the switch-side data transmission device 5 to the switch-side matching device 3 of 64 Kbps. It converts and transmits by RS-232C system at a transmission rate, and transmits framed data received by RS-232C system from switch-side matching device 3 to switch-side data transmission device 5.

The exchange-side matching device 3 converts the framed data received from the exchange-side DSU 4 in the RS-232C scheme into a digital line signal coded in the BPRZ-AMI scheme and converts it into a digital subscriber line of the private exchange 2. The digital line signal received from the digital subscriber line of the private switch 2 is formed into framed data, and then transmitted to the switch side DSU 4 by RS-232C. That is, the matching device 3 separates the voice signal and the control signal from the digital line signal received from the digital subscriber line of the private switch 2, compresses the voice signal by the PCM method, converts the voice signal into a PCM compressed voice signal, and converts the PCM compressed voice. The framed data including the signal and the control signal is generated and transmitted to the DSU 8. In addition, the matching device 3 separates the control signal and the PCM compressed speech signal from the framed data received from the DSU 4, decompresses the PCM compressed speech signal, and reproduces the speech signal and the control signal. It generates a digital line signal that includes and transmits it to the digital subscriber line of the private exchange 2.

Therefore, in the private switching device of the present invention, the remote digital telephone 10 is a matching device 3 connected in the RS-232C manner with the DSUs 4 and 8 connected to the data dedicated line terminals of the data transmission devices 5 and 7. 9, the private exchange service can also be used at a remote location via the public network 6. In other words, the line between the remote digital telephone 10 and the private switching center 2 matches the digital subscriber line of the private switching system 2 with the data dedicated line of the telephone station and matches the data dedicated line of the remote digital telephone 10 with the telephone station. It can be extended.

FIG. 2 is a block diagram showing details of the matching devices 3 and 9 of FIG. The switch-side matching device 3 and the remote subscriber-side matching device 9 may be provided as the same device providing the RS-232C connection and the digital subscriber line connection.

As shown in FIG. 2, the matching devices 3 and 9 include a digital subscriber line connection terminal 11, a time compression multiplexing (TCM) line interface unit 12, a frame forming unit 13, and an RS-232C conversion unit. 14, the DSU connection terminal 15, the PCM processing unit 18, the power conversion unit 17, the DC power supply unit 16, the central processing unit 19, and the display unit 20.

The digital subscriber line connection terminal 11 is connected to the digital subscriber line of the switch 2 when the matching device is the switch-side matching device 3, and the digital telephone 10 of the remote subscriber is connected if the matching device 9 is the remote subscriber-side matching device 9. do. When the switch 2 used is Meridian 1, the transmission rate of the digital line signal is 512 Kbps and the coding method is the BPRZ-AMI method.

The TCM line interface unit 12 matches the impedance with the digital subscriber line or the remote digital telephone 10 of the private switch 2 connected to the digital subscriber line connection terminal 11.

The RS-232C converter 14 converts the framed data into framed data of the RS 232C method.

The DSU side terminals 15 are connected to the exchange side or the remote subscriber side DSUs 4 and 8 to transmit and receive framed data.

The frame forming unit 13 may be implemented by including a programmable gate array (PGA), and the digital line signal and the DSU (4, 8) for transmitting and receiving to and from the digital subscriber line or remote digital telephone 10 of the private exchange (2). Performs conversion between the framed data transmitted and received. That is, the frame forming unit 13 separates the control signal and the PCM compressed voice signal from the framed data received from the DSUs 4 and 8 through the RS-232C converter 14 to convert the PCM compressed voice signal to the PCM processing unit. After transmitting to (18), the voice signal reproduced from the PCM processing unit 18 is received to generate a digital line signal including the voice signal and the control signal. The digital line signal generated in the frame forming section 13 is transmitted to the digital subscriber line or the remote digital telephone 10 of the private switchboard 2 via the TCM line interface section 12.

In addition, the frame forming unit 13 separates the control signal and the voice signal from the digital line signal received from the digital subscriber line of the private switchboard 2 or the remote digital telephone 10 through the TCM line interface unit 12 to generate a voice. After transmitting the signal to the PCM processing unit, the PCM processing unit 18 receives the PCM compressed speech signal to form framed data including the control signal and the PCM compressed speech signal. The framed data formed in the frame forming unit 13 is transmitted to the DSUs 4 and 8 via the RS-232C conversion unit 14.

The PCM processing unit 18 compresses the voice signal separated by the frame forming unit 13 by the PCM method to form a PCM compressed voice signal, and then transmits the generated voice signal to the frame forming unit 13, which is separated from the frame forming unit 13. The PCM compressed speech signal is decompressed and restored to the speech signal. In addition, the PCM processing unit 18 adjusts the level of the audio signal.

The DC power supply device 16 receives a commercial power source of, for example, AC 100 / 220V, outputs DC 24V 600mA, and applies it to the power converter 17.

The power conversion unit 17 receives a DC 24V voltage from the DC power supply unit 18, converts the voltage into DC + 5V, -5V, and + 12V voltages, and applies it to each block of the matching devices 3 and 9.

The central processing unit 19 controls and matches the asynchronous transmission rate of the digital line signals in order to manage the digital line signals transmitted and received by the digital subscriber line of the private exchange 2 and the telephones of the remote digital telephone 10. In addition, the operation state of the entire matching device 3, 9 is monitored and the display of the display unit 20 is controlled.

The display unit 20 displays a power input state of the apparatus, a driving state of the central processing unit 19, a connection state, and a state of transmitting and receiving data. For example, the display unit 20 may include a PWR lamp indicating a power input state, a SYS lamp indicating a normal operation of the central processing unit 19, data with a digital subscriber line of the private switchboard 2 or the digital telephone 10. FIG. And a TEL lamp indicating whether transmission and reception is normal, a TxD lamp indicating a data transmission state, and an RxD lamp indicating a data reception state.

The PWR lamp is turned on when the matching devices 3 and 9 are supplied with power, and the SYS lamp is turned on and the TxD lamp is turned on when the central processing unit 19 is in a normal state. When the exchange side matching device 3 is connected to the digital line of the exchanger 2, the TEL lamp of the exchange side matching device 3 lights up. At this time, after the control signal is sent from the switch-side matching device 3 to the remote subscriber-side matching device 9 and receives a response signal from the remote subscriber-side matching device 3, the matching device 3 , RxD lamp of 9) lights up. After the RxD lamp and the SYS lamp of the remote subscriber side matching device 9 are lit, the remote digital telephone 10 is connected. If the digital telephone 10 is not connected, the TEL lamp flashes. When the digital telephone 10 is connected, the TEL lamp is lit and the display panel of the digital telephone 10 displays the current time of the private exchange 2 after a while.

The voice signal and the control signal of the remote digital telephone 10 are coded into a digital line signal according to the connection scheme of the digital subscriber line of the private switch 2 and transmitted to the remote subscriber side matching device 9. The remote subscriber side matching device 9 converts the digital line signal into framed data and transmits it to the remote subscriber side DSU 8 in the RS-232C manner. The transmitted framed data is transmitted from the remote subscriber side DSU 8 to the exchange side DSU 4 using a data leased line of the public network. The exchange side DSU (4) transmits data to the exchange side matching device (3) in the RS-232C manner, and the exchange side matching device (3) converts the data into digital line signals to the digital subscriber line of the private exchange (2). send. Therefore, subscribers using digital telephones can be provided with private switching services even at remote locations.

The private switching device of the present invention provides a digital private switching service to a remote digital telephone subscriber by implementing a digital subscriber line of a private exchange connecting to a digital telephone using a dedicated protocol and signal specification to be extended using a data dedicated line of a public network. can do.

Although the invention has been particularly shown and described by the foregoing detailed description, it will be appreciated that various changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims. It is self-evident.

Claims (9)

A private switching device for providing a digital private exchange service to a remote digital telephone subscriber, With a private exchange, Public Network, First and second digital service units connected to a data dedicated line of the public network; A digital line signal matched between the digital subscriber line of the private exchange and the first digital service unit and transmitting and receiving a digital line signal including a voice signal to and from the digital subscriber line of the private exchange and storing the framed data having a predetermined structure. First matching means for transmitting and receiving with a digital service unit and performing conversion between the digital line signal and the framed data; Matched between the digital telephone of the remote digital telephone subscriber and the second digital service unit to transmit and receive the digital line signal to and from the digital telephone, and to transmit and receive the framed data to and from the second digital service unit; Second matching means for performing conversion between the data Private exchange device comprising. The method of claim 1 wherein each of the first and second matching means First connection means for selectively connecting a digital subscriber line of said private exchange and said remote digital telephone to transmit and receive said digital line signal; Second connecting means for selectively connecting one of the first and second digital service units to transmit and receive the data; The framed data including the PCM compressed voice signal after separating the voice signal from the digital line signal received from the digital subscriber line of the private exchange and the selected one of the remote digital telephones and converting the voice signal into a PCM compressed voice signal. And decomposing the PCM compressed speech signal from the framed data received from the first or second digital service unit and restoring the speech signal to form the digital line signal including the speech signal. Conversion means, Central processing means for controlling a transmission rate of the digital line signal and monitoring an operating state of the matching means; Display means for displaying an operating state of the matching means Private exchange device comprising a. 3. The digital line signal according to claim 2, wherein the digital line signal is coded in a Bipolar Return-To-Zero-Alternate Mark Inversion (BPRZ-AMI) scheme and is 512 Kbps between the digital subscriber line of the private exchange or between the digital telephone and the first access means. Private switching device that transmits and receives at baud rate. 3. The private exchange device of claim 2, wherein the framed data is transmitted and received between the first or second digital service unit and the second access means in RS-232C manner at a transmission rate of 64 Kbps. The method of claim 1, First transmission means including a data dedicated line terminal to which the first digital service unit is connected at a 64 kbps transmission rate; And a second transmission means having a data-only line terminal to which the second digital service unit is connected at a 64 kbps transmission rate. A matching device for a private switching system for extending a connection between a digital subscriber line of a private exchange and a remote digital telephone through a data-only line of a public network in order to provide a private exchange service to a remote digital telephone subscriber. First connection means selectively connected to said digital subscriber line of said private exchange and said remote digital telephone to transmit and receive digital line signals including voice signals; Second connection means connected to a digital service unit connected to the data dedicated line and transmitting and receiving framed data including a PCM compressed voice signal and having a predetermined structure; Separating the voice signal from the digital line signal received from the digital subscriber line of the private exchange and the selected one of the digital telephones and converting the voice signal into the PCM compressed voice signal to form the framed data, and the digital service unit Conversion means for separating the PCM compressed speech signal from the framed data received from the speech signal and restoring the speech signal to form the digital line signal; Central processing means for controlling a transmission rate of the digital line signal and monitoring an operating state of the matching device; Display means for displaying an operating state of the matching device Matching device for a private exchange system comprising a. 7. The private switched system according to claim 6, wherein the digital line signal is coded in a BPRZ-AMI scheme, and is transmitted and received at a 512 Kbps transmission rate between a digital subscriber line of the private exchange and a selected one of the remote digital telephones and the first access means. Matching device for. 7. The matching device of claim 6, wherein the framed data is transmitted and received between the digital service unit and the second access means in RS-232C at a transmission rate of 64 Kbps. 7. The matching device of claim 6, wherein the digital service unit is connected to the data dedicated line at a 64 kbps transmission rate.