KR950013622B1 - Digital cellular system - Google Patents

Abstract

The device consits of a PCM unit which converts analog signals to pulse code modulation signals, a telephone station which has conventional converter, a mobile communication converter which is connected with the conventional converter, a voice codifying unit which changes transmission rate low, a modem demodulator which demodulates modulated modem determination signals, a fax demodulator which demodulates modulated fax determination signals, a signals detecting unit which is to determine transmission speed and transmission line, a function selecting unit which switches the one of the signals from the voice codifying unit, the modem demodulator, and the fax demodulator, a framer which forms a frame by connecting with the function selecting unit, a modulator which modulates the output of the framer, a digital cellular remote station which transmits the output signals of the modulator, a receiving antenna which receives modulated voice signals, a demodulator which demodulates modulated voice signals, a deframer which gets original information data from a frame, a voice demodulator which demodulates to analog voice signals, a modem modulator which modulates demodulated modem determination signals, a fax modulator which modulates demodulated fax determination signals, a speaker which transmits the output of the voice demodulator, and a jack which connects selectively the output of the modem and the fax modulators with phone lines.

Description

Digital cellular system with non-voice government service function

1 (a) is a block diagram of a conventional digital cellular base station,

(b) is a block diagram of a conventional digital cellular terminal,

2 (a) is a block diagram of a digital cellular base station according to the present invention;

(b) is a block diagram of a digital cellular terminal according to the present invention;

3 is an example of a frame structure in the present invention.

* Explanation of symbols for main parts of the drawings

2: telephone station 3A: digital cellular base station

21 pulse code modulator (PCM) 22 general switch

31: mobile communication switch 32: voice encoder

33: modulator 41: demodulator

42: voice decoder 311: carrier signal detector

312: modem demodulator 313: fax demodulator

314: framer 412: modem modulator

413: Fax modulator SW1 to SW5: Function selector switch

414: DEFRAMER

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-voice information service apparatus in a digital cellular system, and more particularly, to a non-voice information service in a digital cellular system capable of providing voice / non-voice information service regardless of connection information status to a general subscriber.

Conventional digital cellular systems have a PCM 21 and a pulse code at the PCM 21 which converts the analog voice signal of the general subscriber 1 into a 64 (Kbps) pulse code modulation (PCM) signal in FIG. A telephone station 2 having a general exchange 22 for switching a modulated voice signal, a mobile communication exchange 31 interconnected with the general exchange 2, and an output from the mobile communication exchange 31 A speech encoder 32 for converting the 64 (Kbps) PCM signal to a lower transmission rate, a modulator 33 for modulating the output of the speech encoder 32 over a wireless channel, and the modulator 33 It consists of a digital cellular base station 3 equipped with a transmitting antenna ANT1 for transmitting an output signal.

In addition, the conventional digital cellular terminal recovers a modulated voice signal input through the receiving antenna ANT2 and a receiving antenna ANT2 for receiving a modulated voice signal in a wireless channel as shown in FIG. A demodulator 41 to convert the encoded speech information through the demodulator 41 into an analog speech signal, and a speaker for outputting the output of the speech demodulator 42 as a speech signal ( SP).

In the conventional digital cellular system configured as described above, the analog voice signal from the general subscriber 1 is converted into 64 (Kbps) PCM coded voice information via the PCM 21 inside the telephone station 2, and then the digital switch 22 and the digital switch. A call is set up so as to be able to talk to the corresponding terminal through the mobile communication switch 31 inside the cellular base station 3.

Subsequently, the speech encoder 32 converts the signal into a 32 (kbps) analog / digital conversion PCM signal having a lower transmission rate than the 64 (Kbps) signal or a speech coded signal such as an 8 (Kbps) cellular pulse (CELP) and transmits it to a wireless channel. In order to do this, the modulated signal is transmitted through the antenna ANT1.

In this manner, the modulated speech signal is demodulated by the demodulator 41 to restore the encoded speech signal back to the original 64 (Kbps) PCM signal through the speech decoder 42, and then digitally / analog converted. The analog voice signal is transmitted through the speaker SP to enable a call.

However, in the conventional digital cellular system described above, it is impossible to discriminate when a general subscriber is connected to a non-voice connection, and in the case of a voice coder having a transmission rate lower than 64 (Kbps), a modulated signal and a fax through a modem are used. Since the modulated signal of the subscriber cannot be transmitted in the original signal state, the non-voice information service area of the general subscriber is limited.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and includes a carrier signal detector, a modem and a fax demodulator and a framer capable of processing digital signals in an existing digital cellular system. By installing a deframer, a simple digital circuit configuration allows a general subscriber to communicate with a terminal of a digital cellular system via a modem or a fax, and at the same time, automatically discriminates and distributes processing in a corresponding channel section without being controlled by a digital cellular base station. Accordingly, an object of the present invention is to provide a digital cellular system having a non-voice information service function that can improve system utility.

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

Figure 2 (a) shows a block diagram of a digital cellular base station according to the present invention, which is analog from the general subscriber 1, the data terminal 1a via the modem 10 and the fax 1b. A PCM 21 for converting a signal into a pulse code modulated signal, a telephone station 2 having a general switch 22 for switching a pulse code modulated signal at the PCM 21, and the general switch 22 A mobile communication switch (31) interconnected with the mobile communication switch, a voice code (ghk32) for converting the PCM signal output from the mobile communication switch (31) to a lower transmission rate, and a modem discrimination signal modulated at the output of the mobile switch (31). A modem demodulation section 312 for demodulating a signal; a demodulation section 313 for demodulating a modulated fax discrimination signal from a mobile communication exchanger output; on A carrier signal detector 311 for distinguishing whether an input connected to the modem / fax is connected and determining a transmission rate and a transmission line, and the voice encoder 32 according to the transmission line determination of the carrier signal detector 311. It is connected to the function selection switch (SW1, SW2) for switching the input and output signals of the modem demodulator 312, the fax demodulator 313, and the function selection switch (SW2) to record and identify the type of information received by the terminal A framer 314 constituting a frame, a modulator 33 for modulating the framer 314 output to a wireless channel, and a transmitting antenna ANT1 for outputting the modulator 33 output signal are provided. Digital cellular base station 3A.

Also, FIG. 2 (b) shows a block diagram of a digital cellular terminal according to the present invention, which includes a receiving antenna ANT2 for receiving a modulated voice signal in a wireless channel and a receiving antenna ANT2. A restoring unit 41 for restoring the modulated voice signal inputted through the frame, and a form of the frame information output from the demodulating unit 41 to control the selection operation of the function selection switches SW3 to SW5 and simultaneously A demodulator 414 for extracting original information data from the voice signal, a voice decoder 42 for restoring the encoded voice information passed through the deframer 414 into an analog voice signal, and a modem demodulated at the output of the deframer 414. The modem modulator 412 modulates the discrimination signal, the facsimile modulator 413 modulates the fax discrimination signal demodulated at the output of the deframer 414, and the voice demodulator under control of the deframer 414. Speaker SP for transmitting the function selection switch SW3 to SW5 for switching the input / output signals of the firearm 42, the modem modulator 412, and the fax modulator 413, and the output of the voice decoder 42 as a voice signal. And a jack J for selectively connecting the output of the modem modulator 412 and the fax modulator 413 to a telephone line.

Referring to the operation and effect of the present invention configured as described above in detail.

First, the voice or non-voice signal is converted from the general subscriber 1, the data terminal apparatus 1a via the modem 10, or the fax 1b into a PCM signal by the PCM machine 21 of the telephone station 2. General exchange 22 and the mobile communication exchange 31 is connected to each other to set up a call to talk to the terminal, the carrier signal detector 311 determines the type of information of the general subscriber to voice, modem, fax It is divided into.

First, when discriminated by voice signal

The function selector switches SW1 and SW2 are connected to operate the speech coder 32 to convert the PCM signal into a speech coded signal having a lower data rate, and the framer 314 records the information as speech and modulates it into a frame. Will be sent to the terminal.

Second, if it is determined by modem signal

The function demodulation switch SW1 and SW2 are connected so that the modem demodulator 312 operates so that the modulated data signal is demodulated again to restore the original data signal to the framer 314. As shown in FIG., The data is modulated into a frame and sent to the terminal.

Third, if it is determined by FAX

Connect the function selection switches SW1 and SW2 so that the fax demodulator 313 operates so that the modulated image information is demodulated again to restore the original image signal to the framer 314. As shown in the figure, it is recorded, modulated into a frame form, and sent to the terminal.

In this state, the terminal receives the modulated signal, demodulates it through the demodulator 41 shown in FIG. 2 (b), restores the frame signal, and decodes the information in the deframer 414. In this case, only the original traffic information is extracted by removing the start flag START FLAG and the type from the frame.

In this state, first, when it is determined that the voice signal, the function selection switch (SW3, SW4) is connected to operate the voice decoder 42 and the speaker SP to restore the voice signal.

Second, when discriminating with a modem signal, the function selection switches SW3 and SW5 are connected to operate the modem modulator 412 so that the modem modulator 412 is set to the type of frame information. To modulate the data signal and output it to the external connection terminal jack (J).

Third, when discriminating with a fax signal, the function selection switches SW3 and SW5 are connected to operate the fax modulator 413 so that the fax modulator 413 is set appropriately for the type of frame information and the image signal. Is modulated and output to the external connection terminal jack (J).

As described above, according to the present invention, in the digital cellular system, the general subscriber can communicate with the digital cellular system terminal through a modem, a fax machine, or the like, and is automatically determined by the corresponding channel unit even if not controlled by the central control unit of the digital cellular system. By separating, the processing is possible, which improves the service function of the system.

Claims (1)

Pulse code modulation in PCM 21 and PCM 21 for converting analog signals from general subscriber 1, data terminal 1a and fax 1b via modem 10 into pulse code modulated signals. The telephone station 2 is provided with a general switch 22 for switching the signal and the mobile communication switch 31 in contact with the general switch 22, and the PCM signal output from the mobile switch 31 Speech coder 32 for converting to a lower baud rate, modem demodulation section 312 for demodulating the modem discrimination signal modulated at the output of mobile communication exchange 31, and fax discrimination at the output of mobile communication exchange 31 A fax demodulator 313 which demodulates a signal and discriminates between an analog voice signal and a non-voice signal and distinguishes whether an input connected to a carrier frequency is a modem / fax according to a carrier frequency when the non-voice signal is used. Decided Switching one of the input and output signals of the voice coder 32, the modem demodulator 312, and the fax demodulator 313 according to the carrier signal detector 311 and the transmission line of the carrier signal detector 311. A function selector switch (SW1, SW2), a framer (314) connected to the function selector switch (SW2) to form a frame to record and identify the type of information received by the terminal, and a framer (314) output wirelessly. A digital cellular base station 3A comprising a modulator 33 for modulating for transmission on a channel, and a transmission antenna ANT1 for transmitting an output signal of the modulator 33; A reception antenna ANT2 for receiving a modulated voice signal in a wireless channel, a demodulator 41 for restoring a modulated voice signal input through the reception antenna ANT2, and an output from the demodulator 41; By identifying the form of the frame information, controlling the selection operation of the function selection switches SW3 to SW5, and simultaneously extracting the encoded speech information through the deframer 414 and the deframer 414, which extracts original information data from the frame. A modem modulator 412 for modulating the modem discrimination signal demodulated at the output of the voice decoder 41 and the deframer 414 for restoring the speech signal, and a demodulated fax discrimination signal at the output of the deframer 414. Selecting a function of switching an input / output signal to any one of the voice decoder 42, the modem modulator 412, and the fax modulator 413 under the control of the fax modulator 413 and the deframer 414. Jacks for selectively connecting the position (SW3, SW5), the speaker (SP) which outputs the voice decoder 42 output as a voice signal, and the output of the modem modulator 412 and the fax modulator 413 to a telephone line. A digital cellular system having a non-voice information service function, comprising a digital cellular terminal composed of (J).