JPH0773307B2 - Eco-prevention circuit control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an echo prevention circuit control method, and particularly to prevent an echo failure that occurs when a call is made via a network connection function of an exchange forming a communication network. The present invention relates to an echo prevention circuit control method for improving the control of the echo prevention circuit.

[Conventional technology]

Conventionally, this type of echo prevention circuit control method has been used for a call echo generated when a call is made by configuring a wide area communication network.
Echo canceller devices and echo suppressor devices are added to all lines to prevent the occurrence of echo lines.

[Problems to be solved by the invention]

The above-described conventional echo prevention circuit control system has an operation form capable of constantly preventing echo because the echo prevention function is fixedly added to the transmission line. Therefore, for example, when the contents of the call are various such as voice, facsimile signal, and data signal, the echo prevention function is not necessary, or conversely, the call contents that adversely occur are also included. Therefore, there is a drawback in that the transmission lines must be grouped and operated.

Further, the communication network often has a star-shaped transmission path configuration between the exchanges as shown in FIG. FIG. 2 is a block diagram showing an example of a conventional echo prevention circuit control system. In the example shown in FIG. 2, the A station 20, the B station 21, and the C station 22 have a switching function.
Assuming that there is a long distance between the B station 21 and the B station 21 and between the B station 21 and the C station 22, a call between the A station 20-B station 21 and the B station 21-C station 22 is good by the echo prevention devices 201, 202 and 203, 204. However, when making a call between the A station 20 and the C station 22, the echo prevention device is double inserted in the call, which makes the operation unstable. There is.

The object of the present invention is to eliminate the above-mentioned drawbacks and to control the operation and non-operation of the echo prevention circuit in accordance with the contents of route information and communication information at the time of exchange connection processing, thereby stabilizing the echo prevention function. It is an object of the present invention to provide an echo prevention circuit control system that can be effectively operated and that can communicate various communication media by using the same transmission line to efficiently operate a communication network.

[Means for solving problems]

The system of the present invention secures an interface with the transmission line in the echo prevention circuit control system for controlling the operation of the echo prevention circuit arranged in the exchange system for accommodating and connecting the transmission lines of different routes. An echo prevention circuit and an echo control circuit for controlling the operation / non-operation of the echo prevention circuit are interposed between the interface circuit and the transmission device on the output side of the interface circuit and connected to the inter-station transmission path, The operation or non-operation of the echo prevention circuit based on the operation / non-operation control content which is preset based on the route information of the incoming and outgoing routes and the type of information to be communicated when the transmission line is exchange-connected. Is controlled by the echo control circuit.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which a digital exchange switch section 10, an exchange central control unit 11 for controlling connection of exchanges, a storage device 12 attached to the exchange central control unit, and a digital exchange side are provided. A transmission line interface unit 13 having a communication line interface with the exchange switch unit 10 and a control information transmission / reception interface with the exchange central control unit 11, an echo prevention circuit 14 adopting a digital echo cancellation method, a transmission line interface 13 of the exchange. Connected to the echo control circuit 15, which controls the operation of the echo prevention circuit 14 in response to the on / off control information of the echo prevention circuit 14 sent via the communication device 16, the transmission device 16 which interfaces with the inter-station transmission path, and the exchange central control device 11. Common line signaling device 17 for transmitting and receiving exchange control information to and from the exchange switch,
The switch extension telephone 18 is provided.

In Fig. 1, the part surrounded by the alternate long and short dash line is shown only for one way, but the actual exchange system usually has exactly the same contents as this part for each route, The operation at the time of connection will be described.

The extension telephone 18 of the exchange via the route A (not shown) transmission line
Consider the case of an incoming connection to. The extension number, the call type, provided from the remote exchange via the common line signaling device 17,
The route information and the like are sent to the exchange central control unit 11, and the exchange central control unit 11 controls to connect the transmission line interface unit 13 of the route A and the extension telephone 18 of the exchange via the digital exchange switch unit 10. . At this time, the exchange central control unit 11 reads out from the storage unit 12 information that it is necessary to operate the echo prevention circuit of the route A when connecting the route A and the extension, and the transmission line interface unit 13 is set. A command for operation of the echo prevention circuit is issued to the echo control circuit 15 via the. The echo control circuit 15 receives this command and controls the echo prevention circuit 14 to turn it on. As a result, the echo prevention circuit performs echo cancellation processing on the call signal.

Now, when an incoming call is received from the route A to the data terminal device instead of the extension telephone, the storage device 12 outputs information that the echo prevention circuit should not be operated.

Next, consider a case where a relay connection is made from the route A to the route B (not shown). The originating route selection number, the call type, and the route information provided from the central office signaling device of the route A via the common line signaling device 17 are sent to the central control unit 11, and the transmission line interface unit 13 of the route A and the The exchange central control unit 11 controls the connection with the transmission line interface unit of the route B via the digital exchange switch unit 10.

At this time, the exchange central control unit 11 takes out from the storage device 12 the information that the echo prevention circuits of both paths should not be operated when connecting the paths A and B, and the transmission path interface of both paths is taken out. An instruction to disable the echo prevention circuit (pass-through) is issued to the echo control circuit 15 on both paths via the unit 13. When receiving the control to turn off the echo prevention circuit from the echo control circuit, the echo prevention circuits on both paths execute a pass-through operation for transparently passing the call signal without any processing.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, according to the present invention, in the relay exchange connection between the transmission path of each route and the time station accommodation terminal or each route, the communication type such as voice and data, and the route of the incoming route and the outgoing route. Based on the difference in combination, operate the echo prevention circuit,
By performing fine control such as inactivity, the echo prevention function can be operated most stably and effectively in the operation of the communication network, and various communications such as voice, data, and facsimile can be performed using the same transmission line. The media can be communicated, and the communication network can be efficiently operated.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an example of a conventional echo prevention circuit control system. 10 …… Digital exchange switch unit, 11 …… Exchange central control unit, 12 …… Storage device, 13 …… Transmission line interface unit, 14 …… Echo prevention circuit, 15 …… Echo control circuit,
16 …… Transmission equipment, 17 …… Common line signaling equipment, 18 …… Switchboard extension telephone.

Claims (1)

[Claims] 1. An echo prevention circuit control method for controlling the operation of an echo prevention circuit arranged in a switching system for accommodating and connecting a plurality of transmission paths of different routes, the interface ensuring an interface with the transmission path. An echo prevention circuit and an echo control circuit for controlling the operation / non-operation of the echo prevention circuit between the circuit and the transmission device on the output side of the interface circuit and connected to the inter-station transmission path, and When exchanging and connecting the transmission lines, the operation or non-operation of the echo prevention circuit can be determined based on the operation / non-operation control contents that are preset based on the route information of the incoming and outgoing routes and the type of information to be communicated. An echo prevention circuit control system characterized by controlling by the echo control circuit.