JPH0818547A - Ping-pong transmission control system - Google Patents

Abstract

PURPOSE:To interface an exchange and a terminal equipment even when they adopt different coding rules. CONSTITUTION:An exchange 100 and a terminal equipment 200 are in communication connection by the ping-pong transmission system via a transmission line 300. A relay controller 400 is connected onto the transmission line 300. The relay controller 400 is provided with a slave section 401 having a slave function when viewing from the exchange 100 and a master section 402 having a master function when viewing from the terminal equipment 200. A code conversion section 403 of the relay controller 400 converts voice information from the terminal equipment 200 into information with the coding rule for the exchange 100 and provides an output of the converted information to the exchange 100. A code conversion section 404 converts the voice information from the exchange 100 into information having a coding rule for the terminal equipment 200 and provides an output of the converted information to the terminal equipment 200.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ping-pong transmission control system for performing ping-pong transmission communication in which transmission and reception times are divided and information is alternately transmitted on a transmission line.

[0002]

2. Description of the Related Art A configuration is widely used in which an exchange of a network and a terminal in which digital exchange is performed by the exchange perform communication by a ping-pong transmission system (time division direction control system). The ping-pong transmission system realizes bidirectional digital transmission by switching the transmission direction at regular time intervals on a two-wire transmission line.

[0003]

In the ping-pong transmission system as described above, the voice information is communicated by the coding system in the exchange and the terminal by the same coding system. For example,
If the voice compression encoding method of the exchange is the μ-law method, the terminal connected to the exchange must be the μ-law method, and the terminal of the A-law method must be used. I couldn't talk even after connecting.

In addition, the coding rules that are standardly used in various countries around the world do not always match, and in Japan, the μ-law PCM is used.
(Pulse code modulation) is the standard, but in other countries, A law P
It is CM. In this case, another telephone is manufactured in which the CODEC (encoding / decoding circuit) mounted on the domestic telephone and the telephone for other countries is replaced. Therefore, both telephones could not be accommodated in digital exchanges having different coding rules.

Therefore, for example, a PBX (Private Branch Exchange)-
In an electronic exchange system in which terminal-to-terminal communication uses the ping-pong transmission method as described above, when connecting a terminal of a voice coding method different from that of the exchange, in order to connect and call without modifying the terminal Must have a device for exchanging voice codes between the terminal and the exchange.

However, the ping-pong transmission method is basically point-to-point communication, and multi-drop communication for connecting terminals in the middle of the transmission path is impossible in principle. This is because, as described above, the communication system of the time division direction control is adopted, and if the opposite delay times that differ depending on the terminals on the transmission path occur, they will not be synchronized with each other. From such a point, it has been desired to realize a ping-pong transmission control system to which terminals of different coding rules can be connected even with the ping-pong transmission method.

Further, in the ping-pong transmission system, the communicable distance between the exchange and the terminal is limited. Therefore, a ping-pong transmission control system which can further extend the communicable distance by using the ping-pong transmission system is required. Was there.

[0008]

A ping-pong transmission control system according to the present invention, in order to solve the problem of a request for extension of a communicable distance, a ping-pong in which transmission and reception are divided and information is alternately transmitted on a transmission line. In a ping-pong transmission control system that performs transmission communication, a relay control device having a slave unit that terminates ping-pong transmission from one side in a transmission path and a master unit that sends data terminated by this slave unit to the other side. It is provided.

Further, in the ping-pong transmission control system of the present invention, in order to solve the problem of communication demands in different encoding systems, the relay control device is provided with a code conversion unit for converting different encoding rules. is there.

[0010]

In the ping-pong transmission control system of the present invention,
When viewed from one side, the relay control device operates so as to terminate at the relay control device, and when viewed from the other side, operates at the relay control device. Further, in the ping-pong transmission control system of the present invention, in the relay control device, when the encoding system on the one side and the encoding system on the other side are different, the code conversion unit converts the encoding system to the encoding system of the other side and outputs it. . Therefore, the one side and the other side do not need to be aware of the encoding method of the other side.

[0011]

Embodiments of the ping-pong transmission control system of the present invention will be described in detail below with reference to the drawings. First Embodiment FIG. 1 is a configuration diagram showing a first embodiment of a ping-pong transmission control system of the present invention. Prior to this, the basic configuration and operation of the ping-pong transmission control system will be described.

In an electronic exchange system in which PBX (Private Branch Exchange) -terminal communication uses a ping-pong transmission system, for example, in the PBX, the terminals accommodated are 2B (traffic channel) + D (data control channel) + maintenance channel. The digital terminals having the above are widely used, and the line enables ping-pong communication over a predetermined distance with a two-wire (pair) cable.

FIG. 2 is a block diagram showing the configuration of such an exchange and a terminal. As shown, exchange 1 and terminal 2
And are connected by a transmission line 3 composed of two wires. In such a configuration, the ping-pong communication is performed in the opposite communication format between the master (on the side of the exchange 1) and the slave (on the side of the terminal 2) that operates in synchronization with the master. The layer 1 indicates a physical layer in a reference model of OSI (Open System Interconnection). Further, by using such a layered protocol of OSI, it is possible to configure a bus between the layers 1 and 2 and connect a plurality of layers 2.

FIG. 3 is a block diagram of such a system. In the figure, the terminal 2 includes n terminals 2-1 to 2-n.
Are connected to the transmission line 3. These terminals 2-
1 to 2-n form a bus between the layers 1 and 2 and connect a plurality of functions of the layer 2 of each terminal.
Here, the layer 2 is a module that realizes the function of the data link layer that performs frame synchronization and error control.

In order to efficiently accommodate a plurality of terminals 2-1 to 2-n, the exchange 1 sends a right to transmit upstream control information (key information / selection signal information) from the exchange 1 to the terminal 1 to the exchange 1. It may be performed by a polling signal to 2-1 to 2-n (If this is done, P control is performed as compared to PBX control.
The advantage is that the circuit device of the BX becomes smaller).

Then, as shown in FIG. 3, in a system in which a plurality of terminals 2-1 to 2-n are connected to one line,
In response to the polling signal from the exchange 1, each terminal 2-1
Since 2-n acquire the transmission right, they have a function of performing bus contention control between layers 2. As the bus contention control, for example, a method in which each terminal 2-1 to 2-n is set in advance so that the time from the detection of the polling signal to the transmission request is different, and the bus contention does not occur, etc. There is.

Next, in such a system, it is possible to extend the distance of the transmission line 3 and connect each terminal 2-1 to 2-n having a coding law different from that of the exchange 1. Example 1 will be described.

<< Configuration of First Embodiment >> In FIG. 1, the configurations of the exchange 100, the terminal 200 and the transmission line 300 are the same as those of the exchange 1, the terminal 2 and the transmission line 3 shown in FIGS. Further, the relay control device 400 is connected in the transmission path 300.

The relay controller 400 includes a slave unit 401.
And the master unit 402, and viewed from the exchange 100 side,
The relay control apparatus 400 terminates as if it were a terminal (slave), and operates as a master (instead of the exchange 100) for the terminal 200. That is, the slave unit 401
Is a layer 1 as a slave to the exchange 100.
The master unit 402 is configured to perform the layer 1 function as a master for the terminal 200.

Further, in the relay control device 400, the code conversion units 403 and 404 are conversion units for the upstream and downstream voice compression coding rules, respectively. That is, the code conversion unit 40
3 converts, for example, the A-law voice information from the terminal 200 into the μ-law system on the exchange 100 side, while the code conversion unit 404, conversely, converts the μ-law voice information from the exchange 100. To the A-law method on the terminal 200 side.

Switch subscriber control unit 101 of switch 100
Is a circuit block for performing ping-pong transmission control between the exchange 100 and the terminal 200, and shows a case of one line.
Further, the master unit 101a of the exchange subscriber control unit 101
Has a layer 1 function, and SYNC1 (synchronization signal), CL from a control unit in the exchange 100 (not shown)
K1 (clock signal) is received, and the relay control device 40
The communication with the slave unit 401 of 0 is performed.

Slave unit 401 of relay control device 400
Operates in a subordinate synchronization with the master unit 101a of the exchange subscriber control unit 101, and outputs the synchronization signal to SYNC2 and CLK.
Output as 2. The SYNC1 is a ping-pong transmission frame synchronization clock (8 KHz) input from a clock control unit (not shown) of the exchange 100. Also, C
LK1 is a synchronization signal for inputting / outputting a traffic channel (B channel) to / from the layer 1.

SYNC2 is a relay controller 400
It is a frame synchronization signal for ping-pong transmission output from the slave unit 401, and is used as a frame synchronization signal for the master unit 402 in the next stage. Further, CLK2 output from the slave unit 401 is also used as a synchronization signal of the traffic channel input / output signal of the slave unit 402.
In the terminal 200, 200a indicates a slave unit.

Next, the operation of the first embodiment will be described. << Operation of First Embodiment >> First, the slave unit 401 of the relay control device 400 operates in synchronization with SYNC1 and CLK1 received from the exchange 100 through the transmission path 300, and is slave-synchronized with SYNC1 and CLK1. It outputs the signals SYNC2 and CLK2. As a result, the master unit 402 transmits S through the transmission path 300.
Output YNC2 and CLK2 to the terminal 200,
The terminal 200 performs the transmission / reception operation in synchronization with the SYNC2 and CLK2. Therefore, the relay control device 400
And terminal 200 can operate with similar synchronization signals.

Further, in the relay control device 400, Dc
The h (data control channel) and the maintenance channel (used for polling signals here) are simply relayed, and the output of the slave unit 401 is input to the master unit 402.
It is output to the terminal 200.

As described above, in the ping-pong transmission control system of the first embodiment, since the relay control device 400 once terminates in the transmission line 300, the distance of the transmission line 300 can be doubled.

The code conversion operation is performed as follows. For example, when the voice encoding system of the exchange 100 is the μ-law system and the terminal 200 is the A-law system, the following operation is performed. (1) The μ-law voice information from the exchange 100 enters the code conversion unit 404 of the relay control device 400 through Bch. Then, here, the A-law that matches the terminal specifications is converted to the terminal 20.
Output to 0. (2) The A-law voice information from the terminal 200 is the code conversion unit 4
At 03, it is converted into the μ law and output to the exchange 100. (3) Dch (data control channel) and maintenance channel (used for polling signal here) are simply relayed,
The output of the slave unit 401 becomes the input of the master unit 402.

Therefore, even if the terminal 200 has an encoding method different from that of the exchange 100, there is no need to modify the terminal 200 via the relay control device 400, and the same encoding method as that of the terminal 200 is obtained. Can be used.
Further, since the code conversion units 403 and 404 perform data compression, the switch unit of the exchange 100 is, for example, an ATM.
(Asynchronous transfer mode) When the switch is proportional to the traffic channel capacity like a switch, the switch can be effectively used without modifying the existing terminal 200.

Next, a second embodiment provided with a plurality of coding rule conversion units will be described. << Configuration of Second Embodiment >> FIG. 4 is a configuration diagram of a ping-pong transmission control system of a second embodiment. This system uses transmission line 3
00 is provided with a relay control device 500, and the relay control device 500 is configured to perform conversion of a plurality of coding rules. The relay control device 500 includes a slave unit 50.
1, a master unit 502, code conversion units 503 and 504, a selection control unit 505, and a 1/2 control unit 506.

Slave section 501 and master section 502
Have the same functions as the slave unit 401 and the master unit 402 in the first embodiment, respectively. In addition, the code conversion units 503 and 504 include conversion units of three different types of coding rules. In addition, as these encoding rules,
μ-law method, A-law method, ADPCM method, and LDC
There is a voice compression method such as the ELP method.

The selection control unit 505 is a module that performs the functions of layers 2 and 3, and based on the output signal of the 1/2 control unit 506 and the D channel signal, the code conversion units 503 and 504 instructed by the exchange 100. It is equipped with a function to select the coding law that performs the conversion of. Further, the 1/2 control unit 506 outputs half of polling signals described later to the terminal 200, and the other half outputs the relay control device 5.
00 itself has a function of performing control for use for transmission to the exchange 100.

The exchange 100 includes a plurality of exchange subscriber control units 101-1 to 101-n, and subscriber circuit control for controlling these exchange subscriber control units 101-1 to 101-n. The unit 102 is provided. The subscriber circuit control unit 102 includes exchange subscriber control units 101-1 to 101-1.
It has a function of controlling the cycle of the polling signal output from 1-n.

FIG. 5 is a time chart showing the polling signal in the exchange 100 and the operation of the relay control device 500. The subscriber circuit control unit 102 performs control such that the exchange subscriber control unit 101-1 has a polling period of (a) and the exchange subscriber control unit 101-2 has a polling period of (b), for example.

Then, the ½ control unit 506 of the relay control device 500 controls so that half of the polling signal is output to the terminal 200 side and the other half is given to the selection control unit 505. That is, as shown in FIG. 5C, the relay controller 500 uses the first polling signal of the polling signals shown in FIG. 5A, and the terminal 200 uses the next polling signal as shown in FIG. 5D. Alternately use the polling signal. It should be noted that this control is performed by counting polling signals or the like.

Next, the operation of the second embodiment will be described. << Operation of Second Embodiment >> First, the exchange subscriber control units 101-1 to 101-n of the exchange 100 are the subscriber circuit control unit 1.
Under the control of 02, as shown in FIGS. 5 (a) and 5 (b), a transmission permission signal is transmitted in a time division manner over a plurality of lines. Also, the exchange subscriber control units 101-1 to 101-n give instructions for the selection control unit 505 of the relay control device 500 to perform selection control. This instruction is given using the D channel.

In FIG. 6, the switching control device 100 to the relay control device 5 are shown.
00 shows a frame structure of data output to 00. Here, the address A is the terminal 200 or the relay control device 500.
This is an address for instructing As a result, the relay control device 500 passes the instruction to the terminal 200, and the selection control unit 505 reads only the instruction to the relay control device 500.

In FIG. 6, DLE is a dot and H is a header, and these bits represent the beginning of a data block. C is a control bit, DLE and ETX at the rear of the frame represent the end of data, and LRC is a bit for data check. Also, the selection control unit 505 is added to the data section of the layer 3 section.
It includes data such as the designation of the coding method for performing the selection control.

Selection control unit 505 of relay control device 500
On the basis of the instruction information received from the exchange 100, the code conversion unit 503 transmits the selection control signal of the designated encoding method,
Output to 504. Thereby, the code conversion unit 50
In 3 and 504, the conversion unit of the instructed encoding system operates. Further, the 1/2 control unit 506 uses the polling signal transmitted from the exchange 100 using the maintenance channel to perform transmission competition. That is, the half control is performed according to the polling signal so that it can be used once for the relay controller 500 and once for the remaining terminal 200.

Therefore, when the polling signal is given, the terminal 200 performs data transmission, and the relay control device 500 sends the voice information converted by the code conversion unit 503 to the exchange 100 by the polling signal to itself. Output.

As described above, in the second embodiment, the code conversion units 503 and 504 for converting a plurality of different coding rules are provided, and the code conversion units 503 and 50 are in accordance with the higher order instruction.
Since the selection control unit 505 that selectively controls the coding law for performing the conversion of No. 4 is provided, the layer 2 of the selection control unit 505,
Data control communication with the host can be performed by the three functions, and the code conversion method of the relay control device 500 can be selected by an instruction from the host.

In the second embodiment, the relay controller 5
Since 00 has the 1/2 control unit, it is possible to perform the transmission contention control of both the terminal 200 and the relay control device 500 without requiring a complicated configuration for the transmission contention control.

Further, in the second embodiment, the case where a plurality of lines are connected to the exchange 100 has been described.
For example, there is a case where only one line is connected to the exchange 100. In such a case, conventionally, the polling signal is always output (in the case of FIG. 5, it is always low level), but in the present embodiment, the subscriber circuit control unit 102
Regardless of the number of lines to be managed, control is performed such that the non-polling state is set at a predetermined cycle.

As a result, even if only one line is connected, the relay controller 500 can perform 1/2 control of the polling signal without performing complicated control. That is, since the 1/2 control operates by detecting the edge of the polling signal, a valid operation cannot be performed with a signal having no change point. Therefore, even if the mounted terminal has only one line, the polling signal output from the exchange 100 is not fixed to the mounted line, and there is always a polling state and a non-polling state (moving polling is performed. The control is performed on the exchange 100 side.

The code conversion unit 40 in each of the above embodiments
3, 503 and 404, 504 are provided with the scramble function and the descramble function as the processing of the voice information, so that the traffic channel scramble communication can be performed. That is, in this case, the exchange 1
A relay control device having a scramble function and a descramble function for voice information is provided on both sides of the relay station via the 00.

FIG. 7 is an explanatory diagram showing this structure. In the figure, the transmission line 30 on the terminal 200A side of the exchange 100 is shown.
0A and the transmission path 300B of the terminal 200B are connected to relay control devices 600A and 600B having a scramble function and a descramble function of voice information, respectively. And in such a system, for example,
When communication is performed between the terminals 200A and 200B, one relay control device 600A (600B) scrambles and the other relay control device 600B (600A) descrambles.

In the ping-pong transmission control system as described above, when it is applied to data communication, as a relay control device, for example, a DMI (Digital Multiplex Interface) mode and CCITT Recommendation V.27. It is also possible to connect terminals of such different data formats by adding the function of performing data format conversion of 110.

In each of the above-described embodiments, the ping-pong transmission control system has been described in the case of the ping-pong communication between the PBX and the terminal, but the present invention is not limited to this example, and the digital transmission is performed by the ping-pong method. If there is, it is similarly applicable.

[0048]

As described above, according to the ping-pong transmission control system of the present invention, the relay control device having the function of terminating the ping-pong transmission and the function of sending the terminated data is connected in the transmission path. By doing so, it is possible to extend the distance of the transmission path. In addition, the relay control device,
Since it has a code conversion unit that converts different coding rules,
Ping-pong transmission can be performed even with devices having different coding rules.

[Brief description of drawings]

FIG. 1 is a first embodiment of a ping-pong transmission control system of the present invention.
FIG.

FIG. 2 is a diagram showing a basic configuration of a ping-pong transmission control system.

FIG. 3 is a diagram showing a basic configuration of a ping-pong transmission control system having a plurality of terminals.

FIG. 4 is a configuration diagram of a second embodiment in the ping-pong transmission control system of the present invention.

FIG. 5 is a time chart of a polling signal in the ping-pong transmission control system of the present invention.

FIG. 6 is a configuration diagram of a data format in the ping-pong transmission control system of the present invention.

FIG. 7 is a configuration diagram of another connection example in the ping-pong transmission control system of the present invention.

[Explanation of symbols]

100 switch 101a, 101-1 to 101-n switch subscriber control unit 102 subscriber circuit control unit 200, 200A, 200B terminal 300, 300A, 300B transmission line 400, 500, 600A, 600B relay control device 401, 501 slave unit 402, 502 master unit 403, 404, 503, 504 code conversion unit 505 selection control unit 506 1/2 control unit

Claims (5)

[Claims] 1. A ping-pong transmission control system for performing ping-pong transmission communication in which information is alternately transmitted on a transmission path by dividing transmission time and reception time, and a slave unit terminating ping-pong transmission from one side in the transmission path. A ping-pong transmission control system comprising: a relay control device having: a master unit that sends data terminated at the slave unit to the other side. 2. The ping-pong transmission control system according to claim 1, wherein the relay control device includes a code conversion unit that converts different coding rules. 3. The ping-pong transmission control system according to claim 1, wherein the relay control device includes a code conversion unit that converts a plurality of different coding rules, and an encoding that performs conversion of the code conversion unit according to a higher order instruction. A ping-pong transmission control system comprising: a selection control unit that selectively controls a law. 4. An exchange and a terminal connected to the exchange via a transmission line perform ping-pong transmission communication, and a polling signal output from the exchange to the terminal at a predetermined polling cycle causes In a ping-pong transmission control system that controls transmission timing from a terminal to the exchange, a slave unit that terminates ping-pong transmission from one side in the transmission path, and a master that sends data terminated by this slave unit to the other side. A relay control device having a section, and the relay control device outputs half of the polling signal to the terminal, and the other half is used as a transmission control to the exchange by the relay control device. A ping-pong transmission control system having a ½ control unit for performing control for use. 5. The ping-pong transmission control system according to claim 4, wherein the exchange is provided with a subscriber circuit control unit for transmitting a polling signal having a non-polling state at a predetermined cycle regardless of the number of lines to be managed. A characteristic ping-pong transmission control system.