JPH0946311A - Time division multiple access communication system for picture communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain small-scale and highly reliable communication by mixing data from a facsimile(FAX) equipment connected to a general public telephone network with sound data from a telephone set and multiplexing these data with a radio frame. SOLUTION: A FAX mode detecting part 161 always monitors 64Kbps PCM data, judges whether the data are sound data or FAX data and output its corresponding detection signal to control an ADPCM CODEC part 151 and a multiplexing circuit part 191 . When the PCM data are FAX data based upon the detection signal, the circuit part 191 inputs the PCM data as they are and inserts them into a time slot corresponding to each frame. In the case of sound data, the circuit part 191 input 32Kbps ADPCM data, inserts the data into a time slot corresponding to several frames and integrates the data in a time division multiple(TDMA) signal. In the circuit part 191 , the 64Kbps PCM data and 32Kbps ADPCM data having respectively different transmission speeds are multiplexed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time-division multiple access communication system, and more particularly to a communication system in which voice data and facsimile data are mixed and placed on a radio frame for communication.

[0002]

2. Description of the Related Art Image data signals for facsimile or the like are transferred to 32
ADPCM (adaptive diffe) of Kbps
It is said that the method of encoding and transmitting by using the local PCM (adaptive differential PCM) only supports low-speed data transmission. However, there is a demand for high-speed data transmission, and it is necessary to meet this demand.

As a method for solving this, Japanese Patent Laid-Open No. 4-1
Japanese Patent No. 54251 discloses a facsimile communication method. FIG. 4 shows the configuration diagram. This communication system uses a high-speed digital leased line 31a to 31c for exchanges (P
BX) 22, 27 and multimedia multiplexers 23, 28
Is a facsimile communication system for performing data communication between the facsimile devices 21 and 26. When the facsimile mode signaling sent from the facsimile devices 21 and 26 is detected by the facsimile mode detectors 25 and 30, data compression is performed without multiplexing the signaling with the data input from the exchanges (PBX) 22 and 27. When the data is sent out and sent, or when the data is sent from the other party's multimedia multiplexers 26, 25 to the facsimile machines 26, 21 via the exchanges (PBX) 27, 22, it is demodulated and sent out without performing the signaling separation process. A scheme has been proposed.

However, this system is compatible with a network using a high-speed digital leased line that multiplexes signaling in real data and transmits it to a telephone or a facsimile machine to separate it into real data and signaling. However, it does not support a system that attempts to connect a facsimile device to a general telephone network.

[0005]

In the conventional method, since the facsimile machine is connected to the exchange (or PBX) and is transmitted through the high-speed digital leased line, it is expensive and large in scale. was there.

The present invention has been made in view of the above points, and by mixing data of a facsimile machine connected to a general public telephone network and voice data of a telephone in a mixed manner in a radio frame, It is an object of the present invention to provide a time division multiple access communication system capable of reliable communication on a large scale.

[0007]

In order to solve the above-mentioned problems, the time-division multiple access communication system for image communication according to the present invention has one master station and a plurality of slave stations in which voice data and image data are mixed. In the time division multiple access communication system for images, the master station and the slave station perform encoding / decoding means for exchanging voice data or image data sent from the telephone and the image device with encoded data (PCM data). (PCM COD
EC) and data conversion means (ADPCM) for converting the encoded data of the audio data and the audio compression encoded data.
CODEC), detection means for detecting image data (facsimile mode detection), input / output of the audio data or the encoded data of the image data or the audio compression encoded data, and based on the output of the detection means, It has a multiplexing circuit for exchanging the coded data of the image data or the audio compression coded data with the time division multiple access signal, and a radio device (TRX) for modulating and demodulating the time division multiple access signal and transmitting and receiving radio signals. It is characterized by

Further, the encoding / decoding means (PCM C
ODEC) encodes / decodes voice data or facsimile image data and PCM code data of 64 Kbps, and also performs the data conversion means (ADPCM COD).
EC) is characterized in that the audio data is converted between 64 Kbps PCM code data and 32 Kbps ADPCM code data.

The signal of the time-division multiple access communication has a multi-frame structure composed of a plurality of time slots of burst data, image data is inserted in each time slot of the frame, and voice data of every several frames. It is characterized by being inserted into a time slot.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of one embodiment of the present invention.

In FIG. 1, the overall configuration of this communication system is
2N and _one telephone station / facsimile apparatus 3, 12 ₁ ... 12 _{N connected} to them, and the master station and slave stations are connected by a time division multiple access communication system. System configuration.

The master station and each slave station basically have the same structure, and the telephone / facsimile apparatus units 3, 12 ₁ ... 12
_N and a codec 5, 14 ₁ ... 14 _N (hereinafter, referred to as P) for converting the output of the device and the pulse code modulation (PCM) signal.
It is called CM CODEC department. ), And an adaptive, differential, codec 6, 15 ₁ ... 15 _N (hereinafter referred to as ADPCM CODEC section) that performs data compression and demodulation (expansion) of a pulse code modulation signal and an adaptive differential pulse code modulation (ADPCM) signal. , A multiplex circuit unit (TRX) 10, 19 ₁ ... 19 _N for performing time division multiple access multiplexing, and a PCM CODE
The data between the C section and the ADPCM CODEC section and the demultiplexed data in the data multiplexing circuit are monitored to communicate with the facsimile mode detecting section 7, 16 ₁ ... 16 _N which detects the facsimile mode data in the communication data by a radio frame. It is provided with wireless device units 11, 20 ₁ ... 20 _N for performing.

The operation of FIG. 1 will be described below.

In FIG. 1, N (N is a natural number) slave stations 2 ₁ to 2 _N transmit and receive radio frames each having an information signal in a burst-like time slot of a certain fixed time, Communication is performed with the master station 1 by allocating a time slot for each slave station at the same frequency. A specific time slot allocation method for this purpose is telephone /
Due to occurrence of a call signal from the facsimile device, for example, request allocation multiple access (DAMA:
Demand Assignment Multipl
e Access) control or the like is adopted.

[0015] Now, when the audio data or facsimile data is sent from the slave station 2 connected telephone / facsimile unit 12 ₁ to _1, these data the CODEC unit 13 ₁ of the PCM CODEC 14 ₁ of the slave station 2 Is encoded into PCM data of 64 Kbps. The facsimile mode detection unit 16 ₁ constantly monitors the 64 Kbps PCM data, determines whether the data is voice data or facsimile data, outputs a corresponding detection signal, and outputs the ADPCM CODEC unit 15 ₁ and the multiplexing circuit unit 1.
Control 9 ₁ .

Based on the detection signal, the ADPCM CODEC unit 15 ₁ converts the 64 Kbps PCM data into 32 Kbps ADPC when it is voice data.
The data is compressed / encoded and output to the multiplexing circuit unit 19 ₁ .

When the 64 Kbps PCM data is facsimile data, the multiplexing circuit unit 19 ₁ inputs the 64 Kbps PCM data as it is and inserts the 64 Kbps PCM data into a time slot for each frame. When the 64 Kbps PCM data is voice data, the 32 Kbps ADPCM data is fetched, inserted into the time slot of every several frames, and incorporated into the time division multiple access signal.

In this way, in the multiplex circuit section 19 ₁ ,
64Kbps PCM data, 32Kbps ADPC
Data of different transmission rates called M data are multiplexed.

A method for multiplexing data of different transmission rates and
For example, consider using a multi-frame configuration.
Can be FIG. 2 shows the frame configuration diagram. F₁, F₂
... indicates a frame, and in this embodiment, F₁, F₂By
Two multi-frames are constructed. Also, each frame
M (M is a natural number) time slot TS₁~ TS_MTo
It is divided into data for one channel of 64 kbps each.
Data is time-division multiplexed in a burst form. 64 Kbps
In the case of PCM data, frame F₁And F₂ Time
Slot TS_MBurst data is multiplexed to 32 Kbp
In the case of ADPCM data of s, the frame F₁Or
F₂Time slot TS_MBurst data to
It can be realized by doing.

As a multiplexing structure, as shown in FIG. 3, two time slots (TS _MA ,
TS _MB ), in the case of PCM data of 64 Kbps, time slots TS _MA and TS _MB are used, and 32 Kb
Time slot TS in the case of ADPCM data of ps
It is also possible to divide and multiplex within a burst, such as using _MA or TS _MB .

Then, the time division multiple access signals multiplexed as shown in FIGS. 2 and 3 are modulated by the radio equipment section (TRX) 20 ₁ and transmitted to the master station as the multiple access multiplexed radio signals. .

The above-described operations for multiplexing and transmitting to a radio frame are basically the same in other slave stations,
The same applies to the parent station.

Next, the reception processing operation of the radio signal transmitted from the slave station in the master station will be described. The radio device unit (TRX) 11 of the master station 1 demodulates the received radio signal and outputs it as a time division multiple access signal to the multiplexing circuit 10.

The multiplexing circuit 10 demultiplexes the data from the time division multiple access multiplexed signal transmitted from the slave station, and further demultiplexes it into ADPCM data of 32 Kbps of voice data and PCM data of 64 Kbps of facsimile data. . Then, the facsimile mode detecting unit 7 determines whether the data for the telephone / facsimile device of the master station is ADPCM data of voice data or PCM data of facsimile data. In the former case, the separated data is ADPC data.
Output to the M CODEC section 6, and in the latter case,
The separated data is output to the PCM CODEC unit 5.

The ADPCM CODEC section 6 converts the 32 kbps ADPCM data of the voice data into 64 kbps PCM data. Further, the PCM CODEC unit 5 composites PCM data of 64 Kbps and supplies it as telephone data or facsimile data to the telephone / facsimile device.

The reception and signal composite processing operation from the radio signal to the telephone data or the facsimile data is similarly performed in each of the other slave stations.

As described above, the communication in which the voice data of the telephone and the facsimile data of the facsimile apparatus are mixed is performed between the master station and the plurality of slave stations.

In the present embodiment, the configuration of the master station and the slave station of the time division multiple access communication system has been described by taking an example in which each has one telephone / facsimile device for simplification. May be installed in each station. In this case, the multiplex circuit unit and the wireless device unit (T
RX) common circuit, PCM CODEC section corresponding to a plurality of telephone / facsimile devices, ADPCM C
The ODEC unit and the facsimile mode detecting unit are installed, or the configuration of each unit is made to be a multiplexing configuration so that the data from each telephone / facsimile device is multiplexed to the radio frame.

Further, the facsimile mode detection unit is a PC
64 kbps in M CODEC section output section and multiplex circuit section
In the above description, the PCM CODEC unit is configured to be monitored. However, the PCM CODEC unit may be monitored on the telephone / facsimile device side, and the monitoring configuration of two locations is performed only by the PCM CODEC unit. As a configuration for monitoring, the multiplex circuit unit may be configured to separately include a detection circuit for discriminating between voice data and facsimile data. Further, in the present embodiment, the facsimile mode detection unit also controls the ADPCM CODEC unit, and it is not always necessary to operate the ADPCM CODEC unit only when voice data is being output from the telephone / facsimile device. It is not a mandatory matter.

[0030]

As described above, according to the present invention, in the system in which the voice data and the facsimile data are mixed and communicated, the voice data is detected as 32 Kbps by detecting the facsimile data by the facsimile mode detecting section.
64K for facsimile data encoded with ADPCM
By placing each coded by PCM of bps on the radio frame, there is an effect that small-scale high-speed data transmission of voice data and facsimile data can be performed and highly reliable communication can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a frame configuration example of multi-frame.

FIG. 3 is a diagram showing an example of a frame structure of intra-burst division multiplexing.

FIG. 4 is a diagram showing a conventional technique.

[Explanation of symbols]

1 master station 2 ₁ to 2 _N slave station 3, 12 ₁ to 12 _N telephone / facsimile _{4,13 1 ~13 N CODEC 5,14 1 ~14} N PCM CODEC 6,15 1 ~15 N ADPCM CODEC 7,16 _{1 to} 16 _N Facsimile mode detection 8a, 17a _{1 to} 17a _N 64Kbps PCM data 8b, 17b _{1 to} 17b _N 64Kbps PCM data 9a, 18a _{1 to} 18a _N 32Kbps ADPC
M data 9b, 18b _{1 to} 18b _N 32Kbps ADPC
M data 10 and 19 ₁ ~ 19 _N multiplex circuits 11, 20 ₁ to 20 _N wireless devices (TRX) 21, 26 a facsimile apparatus 22 and 27 exchange (PBX) 23, 28 multimedia multiplexing device 24, 29 coder / decoder 25, 30 Facsimile mode detection 31a to 31c High speed digital leased line

Claims (3)

[Claims] 1. In a time division multiple access system for images in which one master station and a plurality of slave stations perform mixed communication of voice data and image data, in the master station and slave stations, a telephone or an image device is used. Encoding / decoding means for converting audio data or image data to be transmitted and encoded data, data conversion means for converting encoded data of the audio data and audio compression encoded data, and image data The detecting means for detecting and the encoded data of the audio data or the image data or the audio compression encoded data are input and output, and the encoded data of the image data or the audio compression encoded data is output based on the output of the detecting means. And a time-division multiple access circuit for converting a time-division multiple access signal and a wireless device for modulating / demodulating the time-division multiple access signal and transmitting / receiving a radio signal. Original connection communication method. 2. The encoding / decoding means encodes / decodes voice data or facsimile image data and PCM code data of 64 Kbps, and the data converting means encodes PCM code of 64 Kbps of the voice data. 2. The time division multiple access communication system for image communication according to claim 1, wherein the data and the 32 kbps ADPCM code data are converted. 3. The signal of the time division multiple access communication has a multi-frame structure composed of a plurality of time slots of burst data, image data is inserted in each time slot of the frame, and audio data of every several frames. 3. The data is inserted in a time slot.
The time division multiple access communication method for image communication described.