KR920003389B1 - Isdn still image telephone system - Google Patents

Abstract

The system includes a displaying device (12) for displaying the telephone number of the other party. A B-channel control means (15) performs exchange functions for the B-channel, and assigns functions to B1 and B2 channels. A data link control means (17) sets and detects flags, inserts and deletes zeros, processes errors, and controls the priority of a D-channel. A system control means (18) performs overall controls for the telephone, and a plurality of interfacing means (13), (14), (16), (21), (22) are connected to proper positions. The system can be applied to the existing telephones at a relatively cheap cost.

Description

ISDN still picture telephone system

1 is an overall configuration diagram of a conventional ISDN telephone.

2 is a block diagram of the present invention.

3 is a transmission switching control circuit diagram of a still picture telephone for transmission.

* Explanation of symbols for main parts of the drawings

10: handset 11: keypad

12: display device 13: input and output interface unit

14: audio interface unit 15: B channel control unit

16 line interface unit 17 data link control unit

18: system control unit 19: transmission dedicated still picture telephone

20: stationary stationary picture telephone 21: stationary input and output interface unit

RA, RB: Resistor C: Capacitor

T: Timer

The present invention relates to an ISDN still picture telephone system in which a still picture telephone operating on a general telephone line and a reference ISDN telephone are connected to enable simultaneous two-way communication of voice calls and still pictures on the ISDN.

A still image telephone is a device capable of communicating still images through a telephone line. The still image communication method of this apparatus transmits an image signal input from a camera by amplitude-phase modulation (carrier frequency: 1747.82 Hz) and transmits it through a telephone line. This device cannot talk with each other during still picture transmission because voice call and still picture communication cannot be done at the same time, and wait until the transmission operation is completed on one side after the other party cannot transmit still picture at the same time even during still picture communication. There was an inconvenience to be sent from one side.

In addition, when using still image telephones over ISDN, a TA (terminal adapter) must be used, which still suffers from the above problems of still image telephones operating on a telephone line.

The present invention transmits to ISDN telephone using only one B channel for voice call among basic access channels (2B + D: B: 64 Kbps, D: 16 kbps) provided by ISDN to solve the above problems of the prior art. Adds a function to connect two dedicated and receive-only still picture phones to the remaining B-channel, and automatically activates the transmission switch of an existing still picture phone that needs to be operated by hand to simultaneously perform voice calls and still pictures on ISDN. Its purpose is to configure the system to enable continuous communication.

To achieve the above object, the present invention provides a handset for voice input and output, a keypad as an input device for dialing numbers, a display device for displaying a dialing number or a counterpart phone number, and a connection to the handset, keypad and display device. And an input / output interface means for connecting to an external ISDN telephone, and connected to the input / output interface means to convert an analog voice signal into a digital signal for encoding, or to decode the digital signal to convert it into an analog signal. An audio interface means for generating various tones, a B channel control means connected to the audio interface means for performing a B channel switching function and a B1 and B2 channel assignment function, and a B channel control means connected to the B channel control means. Frame composition function, start / policy processing function, 100% AMI code processing function, clock Line interface means for DPLL function, frame rearrangement and recovery function for sphere, and connected to the line interface means for flag detection and generation, zero insertion and removal, FCS (Frame for error detection) data link control means for performing check sequence processing, D-channel priority control function, address checking, etc., connected to the data link control means, B-channel control means, audio interface means, and input / output interface means. System control means for overall control of the functional unit, a transmission-only still picture telephone, a reception-only still picture telephone, the transmission-only still picture telephone and a reception-only still picture telephone, and the same hardware structure as the input / output interface means for voice. And input / output for still image processing instead of audio signal It is connected to the interface means, the still input / output interface means and the audio interface means and the system control means and has the same hardware structure as the audio interface means for speech, and comprises a still audio interface for processing a video signal instead of a voice signal. have.

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

1 is an overall configuration diagram of an existing ISDN telephone, which includes a handset 1, a keypad 2, a display device 3, an input / output interface 4, an audio interface 5, a B channel control 6, and a line. It consists of an interface unit 7, a data link control unit 8, and a system control unit 9, and FIG. 2 is a block diagram of the present invention, and includes a handset 10, a keypad 11, a display device 12, Input / output interface unit 13, audio interface unit 14, B channel control unit 15, line interface unit 16, data link control unit 17, system control unit 18, transmission-only still picture telephone unit 19, It consists of a reception-only still picture telephone 20, a still picture input / output interface unit 21, and a still picture audio interface unit 22. FIG. 3 is a transmission switching control circuit diagram of a still picture telephone for transmission, and FIG. Shows a transmission switching circuit diagram of a still image telephone of The transfer switching circuit diagram is shown, and the b diagram is composed of two resistors (RA, RB), a timer (T), and a capacitor (C).

In FIG. 1, the handset 1, the keypad 2 and the display device 3 are connected to the input / output interface 7 and the handset 1 has a microphone and a speaker for voice input and output, and the keypad 2 ) Is an input device for dialing numbers, and the display device 3 is an output device for displaying a screen of dialing numbers or a screen for displaying a telephone number of the other party.

The input / output interface unit 4 is connected to the handset 1, the keypad 2, the display unit 3, the audio interface unit 5, and the system control unit 9 to connect the handset 1, the keypad 2 and the display unit. (3) It performs connection function with external and ISDN telephone.

The audio interface unit 5 is connected to the input / output interface unit 4, the B channel control unit 6 and the system control unit 9, and digitally receives the analog voice signal input from the handset 1 via the input / output interface unit 4. The signal is converted into a signal, encoded, and then transmitted to the B channel controller 6, or the digital signal transmitted from the B channel controller 6 is decoded, converted into an analog signal, and then output through the handset 1 (4). ), And also generates a variety of tones required for the phone.

The B channel control unit 6 is connected to the audio interface unit 5, the line interface unit 7 and the system control unit 9, and is composed of a B1 and B2 channel selector and a B1 and B2 channel switch. In response to the command of 9), the B channel switching function and the B1 and B2 channel allocation functions are performed in the signal input / output with the line interface unit 7.

The line interface unit 7 is connected to the B-channel control unit 6 and the data link control unit 8 to configure the frame structure, activation / deactivation processing, 100% AMI code processing, and clock recovery. Performs DPLL (Digital Phase Locked Loop) rearrangement and recovery. The data link control unit 8 is connected to the line interface unit 7 and the system control unit 9, and is composed of a D-channel controller and a LAPD controller to detect and generate a flag, insert and remove zero, and detect an error. It performs FCS (Frame check sequence) processing, D channel priority control function and address check.

The system control unit 9 is connected to the input / output interface unit 4, the audio interface unit 5, the B channel control unit 6, and the data link control unit 8 to perform overall functions of controlling all functional units of the ISDN telephone.

2 shows a handset 10, a keypad 11, a display device 12, an input / output interface 13, an audio interface 14, a B-channel control unit 15, a line interface unit 16 of an ISDN telephone. To connect the still picture telephone to the data link control unit 17 and the system control unit 18, the control program of the system control unit 18 is changed, and the still image input / output interface unit 22 and the still image audio interface unit 22 are added. You have to.

The operation of the ISDN still picture telephone is as follows.

The transmission-only still picture telephone 19 and the reception-only still picture telephone 20 are the same as the existing still picture telephone. The transmission-only still picture telephone 19 operates only in the transmission mode, and the reception-only still picture telephone ( 20) operates only in the reception mode.

The still image input / output interface unit 21 and the still image audio interface unit 22 have the same hardware (H / W) structure as the input and output interface unit 13 and the audio interface unit 14 configured for voice. The difference is that the video signal is processed instead. The transmission dedicated still picture telephone 19 and the reception dedicated still picture telephone 20 are connected to two audio input terminals and two output terminals of the still input / output interface unit 21, respectively. The video signal transmitted from the transmission-only still picture telephone unit 19 is transmitted to the still picture audio interface unit 22 through the still picture audio interface unit 22, where it is converted into a digital signal, encoded, and then the B channel control unit 15. Is delivered).

On the other hand, the digital video signal transmitted from the B channel control unit 15 to the still image audio interface unit 22 is decoded and converted into an analog signal, and then received only through the still image input / output interface unit 21. 20) to be displayed on the screen. When the still picture is transmitted and received at the same time, sidetone removal measures are taken so that the still picture transmitted by the transmission-only still picture phone 19 is not displayed on the reception-only still picture phone 20 as it is.

In FIG. 3a, the transmission mode operation is performed in the internal circuit of the switch of the still picture telephone when the switch is connected to the ground. In this method, there is a problem in that the switch must be continuously operated by hand in order to continuously transmit still pictures. To solve this problem, a circuit as shown in FIG. 3b is used. This circuit outputs a square wave having a certain period by using the timer T. When the output signal is connected to the switch internal circuit, the transmission-only still picture telephone automatically transmits still pictures continuously. At this time, the still image transmission period can be arbitrarily determined by adjusting the values of the non-resistance RA and RB and the capacitor C. FIG.

When ISDN services become commercially available, ISDN phones that inevitably provide voice calls over ISDN will generally become popular. At this time, if the still picture telephone used in the existing telephone line is connected to the ISDN telephone as in the present invention, it is possible to solve the problem of the still image telephone service in the telephone line at a relatively low price, and at the same time provide an expensive video phone system. It will replace the effect of ISDN service to some extent.

Claims (5)

A handset 10 for voice input and output, a keypad 11 as an input device for dialing numbers, a display device 12 as a screen display device for dialing numbers or counterpart phone numbers, the handset 10 and a keypad 11 And an input / output interface means 13 connected to the display device 12 to perform an external connection with an ISDN telephone, and connected to the input / output interface means 13 to convert an analog voice signal into a digital signal for encoding. Audio interface means 14 which decodes and converts a digital signal into an analog signal and generates various tones required for a telephone, and is connected to the audio interface means 14 to assign a B channel switching function and B1 and B2 channels. B channel control means 15 for performing a function, and connected to the B channel control means 14, ＂S＂ frame configuration function, start / political processing function, 100% AMI code processing function, clock recovery A line interface means 16 for performing DPLL functions, frame rearrangement and recovery functions, and connected to the line interface means 16 for flag detection and generation, zero insertion and removal, and error detection. Data link control (17) means for performing functions such as FCS (Frame check sequence) processing, D channel priority control function and address checking, and the data link control 17 means and B channel control means 16; A system control means 18 connected to the audio interface means 14 and the input / output interface means 13 for overall control of all functional parts of the ISDN telephone, a transmission-only still image telephone 19, and a reception-only still image telephone 20 And the still image telephone 19 and the reception-only still image telephone 20, have the same hardware structure as the input / output interface means 13 for voice, and process video signals instead of audio signals. The same hardware as that of the audio interface means 14, which is connected to the still image input / output interface means 21, the still input / output interface means 21, the audio interface means 14, and the system control means 18, for speech. ISDN still picture telephone system having a structure and consisting of a still audio interface means for processing a video signal instead of a voice signal. The transmission-only still picture telephone (19) according to claim 1, wherein the transmission-only still picture telephone (19) is provided with a timer (T) connected to two resistors (RA, RB) and a capacitor (C) to automatically operate a transmission switch to continuously transmit a still picture. ISDN still picture telephone system, characterized in that configured. The line terminal of the transmission-only still picture telephone (19) according to claim 1, wherein the transmission-only still picture telephone (19) and the reception-only still picture telephone (20) are connected to the still picture input / output interface means (21). Is connected to the voice input terminal of the still input / output interface means 21, and the line terminal of the reception-only still picture telephone 20 is connected to the voice output terminal of the still input / output interface unit 21. Featured ISDN still picture telephone system 4. The transmission-only still picture telephone (19) and the reception-only still picture telephone (20) are respectively connected to a voice input terminal and a voice output terminal of the still input / output interface unit (21). In order to prevent the still image transmitted from the transmission-only still image telephone 19 from being displayed on the reception-only still image telephone 20 by the side tone effect, the still input / output interface means 21 removes the sidetone. ISDN still picture telephone system comprising a means. 2. The still picture input / output interface means 21 and still picture audio interface means 21 are input / output interface means 13 and 13 and audio interface means 13 and 14 used in existing ISDN telephones. ISDN still picture telephone system characterized in that it has the same hardware structure).

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