JPS5992632A - Digital multiplex echo suppressor control system - Google Patents

Abstract

PURPOSE:To easily constitute a digital telephone exchange equipped with many analog circuits by a digital multiplex echo suppressor. CONSTITUTION:A call controller 5 which is in charge of a call connecting process at the starting point of a relay connection corresponds to a corresponding circuit and sends an echo suppressor disabling order signal to a circuit controller 6 through a control bus 8. The circuit controller 6 edits and sends the order signal to the digital multiplex suppressor 11 at the timing of an input/output bus 9. This digital echo suppressor 11 disables an echo stopping function for a channel on a highway 7 specified by the received order. The disabled echo stopping function is enabled when call ends through a control path similar to that in the disabled period.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for a digital multiplex echo suppressor in a digital telephone exchange.

First, an example of a digital telephone switching system equipped with a conventional analog echo suppressor will be described with reference to FIG. In FIG. 1, the telephone switching system includes a time division switch 1, a digital multiplexer 2, a plurality of trunks 3, a plurality of analog echo suppressors 4, a call control device 5, and a line control device 6. It is something. For long-distance calls, such as international calls, where voice propagation time is long and echo is a problem, an analog echo suppressor 4 is installed for each line at the terminal point of the analog line IO, as shown in Figure 1. A method has been adopted in which the analog echo suppressor 4 is installed and the analog echo suppressor 4 is enabled/disabled by the line control device 6. However, with this method, an analog echo suppressor 4 must be installed for each line, so it is not possible to reduce the cost of the line part, which accounts for a large proportion of the total cost of a telephone exchange. - There was a problem.

Therefore, even though the exchange switch was made into a time-division switch to improve economic efficiency, there was a drawback in that it was not possible to achieve a significant reduction in the cost of the exchange. In addition, in the conventional system, since an echo suppressor 4 is installed for each line, a maintenance person has to spend a lot of time to periodically maintain these.

An object of the present invention is to match analog echo suppressors installed individually for each analog line to a digital exchange and replace them with digital multiplexed echo suppressors, thereby making it possible to replace a digital telephone exchange that accommodates a large number of analog lines. It is an object of the present invention to provide a digital multiplex echo suppressor control system that can be configured easily and inexpensively.

An exchange for implementing the digital multiplex echo suppressor control method according to the present invention includes a plurality of analog trunks, a digital multiplexer, a time division switch, a call control device, a digital multiplex echo suppressor, and a line control device. It is equipped with a redundant configuration as required. Analog trunks are used to terminate analog lines and perform analog-to-digital conversion. A digital multiplexer is for multiplexing multiple digital line signals obtained from multiple analog trunks. The time division switch is for controlling the digital multiplexing device, and the call control device is for performing switching processing including control of the time division switch. The digital multiplex echo suppressor is located between the digital multiplexer and the time division switch, and is connected to the two by a highway, for suppressing echoes generated on the line. The line controller is connected to the digital multi-t echo suppressor by an input/output bus, and is further connected to the call controller by a control bus. When a command is sent from the call control device, the single line control device performs processing to enable/disable the echo suppressor function for the digital multiplex echo suppressor.

The present invention will be explained in detail below with reference to one drawing.

FIG. 2 is a block diagram showing an embodiment of the digital multiplex echo suppressor control method according to the present invention. The embodiment of the control system according to the present invention shown in FIG.
and.

The present invention is applied to a system configured with a time division switch 1. Therefore, a digital multiplex echo suppressor 1 is provided between the digital multiplexer 2 and the time division switch 1.
1, a call control device 5 for performing exchange processing including control of the time division switch 1, and a circuit control device 6 are connected by a way 7. The line control device 6 and the call control device 5 are connected by a control bus 8, and the line control device 6 and the digital multiplex echo suppressor 11 are connected by an input/output bus 9. According to the command from the call control device 5,
The digital multiplex echo suppressor 11 is controlled to enable/disable.

The digital multiplex echo suppressor 11 is an echo suppressor for digitally processing the echo suppression operation by multiplexing 120 lines or 480 lines on the highway. Also, a digital multiplexer 2, a highway 7, a digital multiplex echo suppressor 11 . Line-related devices such as the input/output bus 9 and the line control device 6 are mainly configured using L8I and IO, which have a low failure rate, to reduce the probability of failure. Since it directly affects 120 lines or 480 lines, all of them employ a duplex redundant structure to further increase reliability.

Next, the operation of the digital multiplex echo suppressor control system according to the present invention constructed as described above will be explained in the case of relay connection of an international exchange. Generally, in an international exchange having the configuration shown in FIG. 2, the digital multiplex echo suppressor 11 is enabled when the line is idle, disabled at the time of starting a relay connection, and disabled at the time of terminating a call. Control is performed so that it is re-enabled at a certain point in time. First, the point K when starting the relay connection
Then, the call control unit [5], which manages the call connection process, corresponds to the line in question and sends an echo suppressor disable order to the line control unit 6 through the control bus 8. The line control device 6 edits the above order in accordance with the timing of the input/output bus 9 and sends a disable order to the digital multiplex echo suppressor 11. The digital multiplex echo suppressor 11 operates to disable the echo suppression function for the channel on the input/output highway 7 specified by the reception order. A disabled echo rejection feature is enabled at end of call using the same control path as when disabled.

As explained above, in the present invention, by digitally multiplexing echo suppressors for analog lines and adopting an echo suppressor control method that matches digital telephone exchanges, line-related equipment can be made economical and highly reliable. It has the effect of being configurable. In addition, since a duplex redundant configuration is adopted, in the event of a failure, diagnosis is performed by offline program control from the call control device, and faulty packages can be pointed out in a short time, resulting in good maintainability. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a configuration for realizing a conventional analog echo suppressor control method. FIG. 2 is a block diagram showing an embodiment of a configuration for realizing the digital echo sub-7-receiver control system according to the present invention. 1... Time division switch 2... Digital multiplexing bag R3... Trunk 4...
・Analog echo suppressor 5...Call control device 6...Line control device 7...
・Highway 8... Control bus 9... Input/output bus 10... Analog line 11... Digital multiplex echo suppressor Patent applicant NEC Corporation Representative Patent attorney I) Ro Hisashi 8-

Claims (1)

[Claims] a plurality of analog trunks for terminating analog lines and performing analog/digital conversion; a digital multiplexing device for multiplexing a plurality of digital line signals obtained from the plurality of analog trunks; and the digital multiplexer. A time-division switch for controlling equipment, a call control device for performing exchange processing including control of the time-division switch, and a digital multiplexing device located between the equipment and the time-division switch and connected to a highway. a digital multiplex echo suppressor for suppressing echo on one line, and the digital multiplex echo suppressor is connected by an input/output bus, and is connected to the call control device by a control bus, and the call control device a line control device for enabling/disabling the echo suppressor for the digital multiplex echo suppressor according to a command from the digital multiplex echo suppressor, and the digital multiplex echo is characterized in that the digital multiplex echo suppressor is configured to enable duplexing and redundancy as necessary. Suppressor control method.