JPS63117544A - Digital exchange - Google Patents

Abstract

PURPOSE:To perform a tripartite call with balanced sound volume in the tripartite call including a central office, by amplifying the sound volume of the central office by using a multiplier, and amplifying a voice signal after converting it to a digital signal. CONSTITUTION:When the tripartite call among the central office lines 12 and 13, and an extension 14 is held, a time switch 3 sends sound data A and B from the central office lines 12 and 13 to the multipliers 8 and 7 respectively based on the information of a call control part 2, and amplifies them by multiplying them by a constant and sets them as sound data X and Y. The data X and Y are inputted again to the switch 3, and after time divisional switching being applied, are sent to an addition processing part 5. The processing part 5 replaces the data by the sound volume data in which the unbalancing in the sound volume is corrected, in such way that the data A is replaced by a data (Y+C), the data B by a data (C+X), and a data C by a data (X+Y), and they are sent to a time switch 4, and the time switch 4 sends a voice decoder to CODECs 1a-1c.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a digital exchange.

2. Description of the Related Art Conventionally, there have been digital exchanges that convert voice signals into digital signals and transfer voice data converted into digital signals. Some of these digital exchanges have a three-party call function that allows three parties to talk at the same time. The three-party call processing section of a conventional digital exchange will be explained below.

FIG. 3 is a block diagram of a three-person call processing unit using a conventional digital exchange, and 18a to 18d each have an input terminal for an audio signal and an input terminal for a digital signal. It is a codec that converts a signal into a digital signal, and when a digital signal is input, converts the digital signal into an audio signal. Reference numeral 19 denotes a call control unit that connects the calling station and the called station. 20
2 is an addition processing unit that adds signals converted into digital signals, and 21 to 24 are office line trunks, respectively. 25 and 26 are office lines, 27 and 28 are extension telephones, and 29 and 30 are time switches.

In this apparatus, the codecs 18a to 18d convert audio signals into digital signals, and send digital audio data A to D to the time switch 29, respectively. time switch 2
9 time-divisionally exchanges the audio data based on the information from the call control section 19 and sends it to the addition processing section 2o.

The addition processing section 20 converts data A into data B+C.

The voice data is replaced with data B as data C+A, data C as data A+B, and sent to the time switch 30. Forward. Thus, the calling party can hear the voices of the two called parties, and the called party can hear the voices of the calling party and the other called parties.

FIG. 4(a) is a frame configuration diagram of the communication path 31;
b) is a frame configuration diagram of data on the communication path 32;

Problems to be Solved by the Invention However, when making a three-party call using the above configuration, two central parties and one extension, or one central telephone
When a call is made between a person and two extensions, between the office line 25 and the office line trunk 21 in FIG. 3, the office line trunk 22 and the codec 1
8a, there is a transmission loss in the subscriber line between the codec 18b and the office line trunk 24, and between the office line trunk 23 and the office line 26, so the difference between the voice from the office line and the voice from the extension line is There was a problem in that there was a difference in volume between the two called parties, and the volumes of the two called parties were different.

Means for Solving the Problems In order to solve the above problems, the present invention includes a multiplier for amplifying the digital signal sent from the central office line during a three-party call.

Effect of the Invention With the above configuration, the volume of the central office line is increased by the multiplier during a three-party call, and the volumes of the extension line and the central office line are equalized.

Example Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a three-party call processing section of a digital exchange according to an embodiment of the present invention. In Figure 1, 1a
~1d each converts the audio signal into a digital signal,
It is also a codec that converts digital signals into audio signals. Reference numeral 2 designates a call control unit that controls the time switch 3.4 and connects the calling station and the called station, and 5 represents an addition processing unit.

6 and 7 are multipliers.

The operation of the three-party call processing unit of this embodiment configured as described above will be explained below for the cases where a call is made between two parties on the central office line and one party on the extension line, and when the call is made between one party on the central office line and two parties on the extension line. I will explain it separately.

In this apparatus, the audio signals are digitized by codecs 1a to 1d, and digital audio data A to D are respectively transmitted.

(1) Case of two parties on the central office line and one party on the extension A case will be explained using an example in which a three-party telephone call is made between the central office line 12, 13 and the extension 14. Based on the information from the call control unit 2, two central parties and one extension
When a party makes a three-way call, the time switch 3 is switched to the central office line 12.
The audio data A1B from 13 is sent to multipliers 6 and 7, respectively, and multiplied by a constant and amplified to become audio data X and Y. The volume-amplified audio data X and Y are again input to the time switch 3, time-divisionally exchanged, and sent to the addition processing section 5. The addition processing unit 5 replaces data A with data Y+C1, data B with data C+X, data C with data X+Y, and audio data with the volume imbalance corrected, and sends them to the time switch 4, and the time switch 4 converts the audio data into the codec 1a. ~1c.

FIG. 2(a) is a frame configuration diagram of data on the communication path 16;
FIG. 2(b) is a frame configuration diagram of data on the communication path 17.

(2) In the case of one party on the central office line and two parties on the extension line A three-party call between the central office line 13 and extension lines 14 and 15 will be explained as an example. When a three-way call is made between two parties on the office line and one on the extension line based on information from the call control unit 2, the time switch 3 sends audio data A from the office line 12 to the multiplier 6, and multiplies it by a constant to amplify the volume. Let it be audio data X. The volume-amplified audio data X is again input to the time switch 4, time-divisionally exchanged, and sent to the addition processing section 5. The addition processing unit 5 replaces audio data A with data C+D, data C with data D+X, data D with data
Send to s lc, ld.

FIG. 2(C) is a frame configuration diagram of data on the communication path 16;
FIG. 2(d) is a frame configuration diagram of data on the communication path 17.

Effects of the Invention As described above, according to this embodiment, since the volume of the central office line is amplified using a multiplier, the audio signal is amplified after being converted to a digital signal, and the degree of amplification can be precisely adjusted. Even in the case of a three-party call including a central office line, the three-party call can be made at a balanced volume.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a three-party call processing section of a digital exchange according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a frame of the same data, and FIG. 3 is a block diagram of a three-party call processing section of a conventional digital exchange. The block diagram in FIG. 4 is a diagram showing the structure of the same data frame. 13-1c... Codec 2... Call control unit 3.4
...Time switch 5.. Addition processing unit 6.7.. Multiplier 8-11.. Office line trunk 12.13.. Office line

Claims (1)

[Claims] A plurality of codecs that convert the audio signal into a digital signal when connected to a central office line or an extension line and convert the audio signal into a digital signal when the audio signal is input, and convert the digital signal into an analog signal when the digital signal is input, and the digital signal output from the codec. with a time switch for time-sharing exchange,
a call control unit that controls the time switch; and if the digital signal output from the time switch is an output signal of a codec connected to a central office line among the codecs, the signal is amplified and then sent to the time switch; 1. A digital switching system comprising: a multiplier that returns an amplified digital signal; and an addition processing section that adds digital signals from the time switch and outputs the sum to the time switch.