JPS6030143B2 - Call route system in distributed control exchange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a distributed control method, particularly a loop highway conversion system, in which a plurality of telephones or a plurality of subsystems are connected on a loop highway to control calls.
This is related to Okukatsu's communication route system.

In all conventional exchange systems, functions were concentrated in the switchboard, but with the development of electronic circuit technology, digital technology, and LSI technology, exchange machines with distributed functions can be realized at low cost, and functions can be controlled in a distributed manner. This is expected to reduce the burden on system building block software and improve system reliability.

In the conventional communication path system, transmission from terminal A to terminal B uses time slot i, transmission from terminal B to terminal A uses a different time slot j, and communication path between terminal A and terminal B is One method uses the same time slot between terminals A and B, and the upper half of the loop is used for selection from terminal A to terminal B, and the lower half of the loop is used for selection from terminal B to terminal A. It is considered.

However, with the above two methods, in order to make a conference call with a new terminal C during a call with terminals A and B, a trunk is provided to perform calculations for the new conference, and the conference calculations are performed there and each terminal A different signal must be sent to each. For example, terminal A must be sent the result of addition between terminals B and C, terminal B must be sent the result of addition between terminals A and C, and terminal C must be sent the result of addition between terminals A and B. In the traditional communication path connection system, when a conference call was to be held, a new conference trunk had to be installed and the connection of the communication path had to be changed. In view of the above circumstances, it is an object of the present invention to provide a communication path system in a distributed control exchange that does not require conference trunks.

The present invention connects a plurality of terminals and subsystems to a loop highway in a distributed communication system, and frames and time slots for accommodating time division multiplexed signals are provided on the loop highway.

Each terminal and subsystem removes a signal that was previously transmitted in a frame and circulated on this loop highway from a time slot of a designated frame on the loop highway, and uses this as a received signal. Then, a communication path is created by adding a new signal to be transmitted to this received signal and transmitting it to a time slot within the frame. Therefore, even when making normal 2-party or 3-party calls, you can easily control the communication path without switching time slots on the loop highway or setting up new conference trunks. You can make calls.
FIG. 1 shows a block diagram of a distributed switch.

In the figure, 1 is a loop highway, and on this loop highway there are notes N,,2,,N2,22,
N3,23, N4,24, N5,25 and S,,
3, is connected.

Nodes 21 to 25 have subsystems 4 and 4, respectively.
5 is connected. Node S,,3, connects to node S2,32,subsystem 46 via another loop highway 5.
is being followed. The subsystems 4, to 46 represent (telephone) terminals, trunks, ATs, and the like.

Each node has a subsystem controller connected to it. FIG. 2 shows an example of a frame format on a loop highway.

In the figure, Fn is the nth frame, and each frame includes a synchronization signal SYC, a plurality of channels CH, ~C
Hn and the control signal CON of these channels
Have T. Channels CH, -CH are time slots to which time-division multiplexed audio signals (digital signals) from each terminal are assigned. Now, the case where a telephone call is made between the terminal 4 and the terminal 42 will be explained using FIG.

At this time, it is assumed that CHi is assigned as a time slot. The audio signal from the terminal 4 is converted into a digital signal by the A/D converter 62 via the hybrid circuit 6, and then supplied to the nodes N, 2. Node N,,2. terminal 4. transmits terminal 42's signal Bn-2 received from loop highway 12 in the previous frame to terminal 42's signal Bn-2. The signals An-, from the loop highway A-, are added together and sent to the loop highway A-,. Node N2,22 subtracts its own signal Bn-2 sent in the previous frame from the added signal of channel CHi of loop highway 1, and generates signal An.
-, only is received. This received signal is converted into an analog audio signal by the D'A converter 73 and sent to the terminal 42 via the hybrid circuit 7. The same goes for sending the audio signal from terminal 42 to terminal 4. FIG. 4 shows an example of the configuration of nodes N,,2.

Although the node N,,2, also includes a control device 200 other than the terminal 4, a communication circuit 100 for controlling the communication of the terminal 4 is shown here. register 101 for receiving data from
, 102, and has a register 103 that holds data to be sent to the loop highway. Further, A' is connected to the terminal 4 via a hybrid circuit 104 and digitizes the audio signal from the terminal 4. o/^ converter 1 that converts data sent to converter 105 and terminal 4 into analog
Has 06. Furthermore, it has adders 109 and 110 as well as a register 107 and a buffer register 108 for holding the digitized audio signal from the terminal 4. This is controlled by control circuit 11. Now terminal 4, and 42
and is communicating using channel CH as a time-division communication path, the control circuit 111 transfers the contents of channel CHi (An-20Bn-
, ) into the register 101.

Here, A is an audio signal from the terminal 4, and B is an audio signal from the terminal 42 (both are digital signals, hereinafter referred to as audio data). Furthermore, the suffixes An-2 and Bn- indicate the (n-2)th and (n-,)th transmitted frame numbers, respectively. The register 102 stores the channel CH data (An-30Bn) of the previous frame.
-2) is maintained.

Here, An-3 is audio data sent from terminal 4 three frames ago. On the other hand, the buffer register 108 consists of four registers in this example, and the buffer register 108 stores the four previously sent audio data An-, An-2, Ship A, An-4.
It accommodates.

Therefore, the audio data Bn-2 from the terminal 42 can be extracted by subtracting the audio data An-3 of three frames before in the buffer register 108 from the contents of the register 102 using the adder 109. This audio data B'2 is sent to the terminal 4 via the D/A converter 106 and the hybrid circuit 104. At the same time, this audio data Bn-2 is supplied to the adder 11. Adder 11
0 is the audio data to be transmitted in the original 107 An-,
and this audio data Bn-2 are added and supplied to the register 103. The contents of register 03 are sent out on channel CHi by control circuit 111. In addition,
The control circuit 111 controls the gate 112, and allows all data on the loop highway 1 other than the channel CHi assigned to this call to pass through as is, and prevents the data on the loop from being sent as is at the timing of channel CH. ing.

When the data reception signal is completed, the contents of register 01 are transferred to the next register 102, and the contents of register 01 are transferred to the buffer register 102.
8, new audio data is input. Next, the case of a three-party call will be explained using FIG.

The operations performed at each node in this case are basically the same as those in a two-party call, and the data on the loop highway is the sum of the audio signals from the three terminals. However, in the case of the communication circuit shown in FIG. 4, the data is delayed by one frame at the node to which the terminal for the conference is connected, so in a three-party conference there is a delay of three frames. Therefore, the adder 109 shown in FIG.
You need to subtract it from 2. In Figure 5,
Regarding node N,,2,, loop highway 13
When the audio data An-30Bn-20C', is supplied from the node N,,2, the audio data An-40Bn-30Cn-2 supplied in the previous frame is From A
Bn-30Cn-2 obtained by subtracting n-4 is sent to terminal 4, and new audio data An-, is added to this Bn-30Cn-2 and output to loop highway 1. ing. The same applies to nodes N2, 22 and N3, 23. Similarly, in a four-party conference, a delay of four frames occurs, but by increasing the register buffer, multi-party communication is possible. As described above, according to the present invention, when conducting a conference call, there is no need to newly provide a conference call trunk or use a new time slot, so a complete group configuration can be achieved for the conference. .

In addition, the call path control for this purpose is simplified, and the fixed part for conference calls can be eliminated, making it possible to take advantage of the advantages of the distributed control system.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIGS. 2, 3, and 5 are diagrams for explaining the operation of an embodiment of the invention, and FIG. 4 is an embodiment of the invention. It is a block diagram of the main part of an example. 1...Loop highway, 2,,22,...,25...Node, 4,,42,...45...Subsystem, 100.
...Telephone circuit. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a distributed exchange having a plurality of subsystems connected on a loop highway and having frames and time slots for accommodating time division multiplexed signals on the loop highway, the subsystem is connected to a designated point on the loop highway. a removing means for removing a signal previously transmitted by this subsystem and circulating on the loop highway from a signal in a time slot of a frame; a means for processing a signal from the removing means as a signal to the subsystem; A communication channel in a distributed control exchange characterized by comprising means for transmitting a signal obtained by adding a new signal to be transmitted to a time slot of a designated frame on the loop highway. method.