JPH07118752B2 - Telephone switching equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a telephone exchange device having a function of adjusting a signal level.

[Prior Art] Conventionally, the level adjustment of voice and audible sound in such an exchange has been performed using an amplification / attenuation circuit individually provided for each subscriber such as a telephone set or a subscriber circuit.

In addition, when the PB (push button) signal is used as a control signal for remote control instead of as a selection signal, it is used as a selection signal according to the regulation of the transmission power except when it is used for a call according to regulations such as terminal equipment. Compared with the case, the level must be greatly attenuated before transmission. Conventionally, an attenuation circuit is used in the state of an analog signal in the station line interface, or a DSP ( Digital signal processing processor) was used to perform level attenuation.

[Problems to be Solved by the Invention] In the above-described conventional example, in the case of adjusting the level of voice and audible sound, the same number of amplification / attenuation circuits as the number of subscribers are required, and as the number of subscribers increases, It has the drawback of increasing the number of parts and cost. The amplification / attenuation circuit is
Most of them deal with voice and audible sound in the form of analog signals, and there is a drawback that the adjustment method is not uniform due to variations in amplification / attenuation characteristics due to the circuit configuration.

On the other hand, even in the case of adjusting the level of the PB signal, in the conventional example in which the level is attenuated by providing an attenuating circuit in the above-mentioned local line interface, the case of using the PB signal as a normal selection signal and the control signal for remote control It is necessary to control switching of whether or not to activate the attenuating circuit depending on the case, and the attenuating circuit must be provided for each station line, and the number of parts increases as in the case of voice signals. In addition to the drawback that the cost is increased, a control system for the attenuation circuit is required, and further, the control becomes complicated in order to flexibly adjust the level. Further, in the conventional example in which the level of the PB signal is adjusted by using the DSP in the PB signal generation unit, first, there is a drawback that the DSP is high in cost, and further, a control system for the DSP must be prepared. There was a drawback.

[Means for Solving the Problems] Therefore, the present invention has been proposed in order to solve the above problems, and an object thereof is to input first and second audio signals, and Simplifying the configuration for level adjustment by adjusting the level of the audio signal using a three-party conference circuit that outputs a third audio signal corresponding to the result of adding the audio signals and adjusting the level. The present invention provides a telephone switching device.

A telephone exchange apparatus of the present invention for solving the above-mentioned problem is a speech path switch, and first and second voice signals are input from an output of the speech path switch, and the first and second voice signals are added. And a three-party conference circuit that outputs a third audio signal corresponding to the result of level adjustment to the input of the communication path switch, and a fourth audio signal whose level is adjusted from the input fourth audio signal. In order to obtain the signal, the communication path switch is controlled to supply the input fourth audio signal to the three-party conference circuit, and the signal for using the three-party conference circuit for level adjustment is provided. And a supply means for supplying the three-way conference circuit.

[Embodiment] An embodiment in which the present invention is applied to a private branch exchange of a key telephone will be described below with reference to the accompanying drawings.

<Adjustment of Voice and Audible Sound> First, with reference to FIG. 1, an embodiment relating to the level adjustment of voice and audible sound will be described. In the figure, 1 is the main unit of the private branch exchange and the key telephone, 2a, 2b and 2c are telephones, and the telephones 2a and 2b are telephones as extensions of the main unit 1.
2c is connected via an office line. The main unit 1 is composed of a line interface 3, a speech path switch 4, a controller 5, an audible sound generating circuit 6, a three-party conference circuit 7, a maintenance switch group 8 and the like.

The line interface 3 detects call origination / disconnection for the telephones 2a, 2b, 2c connected as extension lines and office lines, transmits / receives a selection signal, and encodes an analog voice signal by PCM (pulse code modulation). Controls decryption. The communication path switch 4 exchanges the time slot (allocated time position in the time-division multiplexed) of the time-division-multiplexed PCM signal which is input from the input highways of # 1 to # 3.
The output to the output highways of # 1 to # 3 controls the switching of the communication path. The control unit 5 controls the line interface 3 and also controls the call path switch 4
To set the communication path. The audible sound generation circuit 6 is
This circuit generates various tone signals and PB signals and sends them to the # 2 incoming highway. An EEPROM (electrically erasable and writable read-only memory) 501 in the control unit 5 stores a communication path for obtaining an output level set for each telephone by the level adjusting function of this embodiment. It is a thing. This is because the call path for obtaining this output level differs depending on the set level even for the same telephones.

The three-way conference circuit 7 adds the PCM signals of the same time slot on the output highways of # 2 and # 3 in the state of being linearly converted, and again converts them into the nonlinear PCM signal, and this is converted. This is a circuit for transmitting the PCM signal to the time slot after a predetermined number on the input highway of # 3. The predetermined number of delays is a delay of 2 slots in this embodiment. The maintenance switch group 8 includes switches for setting extension telephone numbers and setting output levels of the respective telephones.

With this three-party conference circuit 7, for example, an outside line telephone 2c
Can communicate with the extension telephones 2a and 2b. Second
The figure shows the internal configuration of the tripartite conference circuit 7. In FIG. 2, the 701 linearly expands two PCM signals (denoted by X and Y), performs the operation of Z = α (X + Y), and then compresses Z into a non-linear PCM signal again. It is an arithmetic circuit that does. In this embodiment, the above calculation is performed by an adder and a multiplier (not shown) in the calculation circuit 701. The value of α is usually 1/2. α is 1/2 <α ≤
When set to 1, if the sum (X + Y) of the inputs X and Y exceeds the maximum input level, the above calculation result will be saturated. 70
2 is an S / P converter for converting serial PCM signals from the # 2 output highway and # 3 output highway into parallel, and 703 converts the parallel PCM signals into serial,
# 3 is a P / S converter that sends to the highway. Also, 7
Reference numeral 05 denotes an EEPROM that stores the output adjustment level (value of α in this embodiment) of each telephone. In FIG. 1, a telephone set
2a, 2b, 2c are time slots 1, 2, and n (hereinafter, respectively) on # 1 incoming highway and # 1 outgoing highway 1.
TS ₁ , TS ₂ , TS _n ). Further, a silent PCM signal is input from the audible sound generation circuit 6 to TS ₁ of the # 2 input highway.

When realizing a multi-party call by the three-party conference circuit 7, the following is performed. For example, when simultaneously talking with 2a, 2b, 2c, (C, ... B, A) of (TS _n , ..., TS ₂ , TS ₁ ) on the # 1 incoming highway is output from # 2. For the highway (TS _n , ..., TS ₂ , TS ₁ ), output in the order of (..., A, C, B), and output the highway (TS _n , ..., TS ₂ , T) of # 3.
For S ₁ ), output in the order of (..., B, A, C) The three-way conference circuit 7 adds (..., α (A + B), α (A + C), α (B + C), to (TS _n , ..., TS ₂ , TS ₁ ) of the # 3 incoming highway.
,) Are output in this order.

Under the above settings, the value of α in the arithmetic circuit 701 in FIG.
In the case of, the control of the control unit 5 in the case of adjusting the level of the voice A of the telephone 2a to 1/2 and transmitting it to the telephone 2b will be described below in accordance with the flow chart of FIG.
In this case, if you explain the result first,
A on TS ₁ is converted to A / 2 and sent to TS ₂ on the highway # 1.

In step S1, and controls the speech channel switch 4 from the control unit 5, the # 2 output highway inputs to the three party conference circuit 7 TS ₁
# 1 incoming highway with phone 2a assigned to TS ₁
Connect. At Step S2, TS of highway # 3
_1, the # 2 input highway silence is assigned TS ₁
Connect. The voice A and the silence of the telephone 2a are converted into A / 2 by the three-party conference circuit 7 according to Z = α (X + Y) (α = 1/2), and TS _{3 of the} # 3 highway Is output to. In step S3, the TS ₂ of # 1 out highway 1 phone 2b are assigned, # 3 input highway T
By connecting S ₃ , the voice A / 2 of the telephone 2a whose level has been adjusted to 1/2 is transmitted to the telephone 2b.

Although the case where the level of the sound is adjusted to 1/2 has been described above, the level of various audible sounds generated by the audible sound generating circuit can be similarly adjusted in addition to the sound. Further, by setting the value of α of the arithmetic circuit 701 of the three-party conference circuit 7 to an arbitrary value of 0 <α ≦ 1/2, the level can be attenuated by α times. The value of this α is stored in the EEPROM 705.

The case of amplification will be described. In Figure 3 the flow chart of step S2, by changing and so connect the # 1 of the incoming highway TS ₁ to TS ₁ of the # 3 out highway, Z = alpha by (A + A), the # 3 input highway 2αA is output to TS ₃ . Here, by setting α to an arbitrary value of 1/2 <α ≦ 1, the output level can be amplified by 2α times in a range where saturation is not achieved.

As described above, by using the three-party conference circuit, the levels of voice and audible sound can be easily adjusted in the main device only by controlling the setting of the communication path. At this time, the value of α is stored in the ROM 705 of the tripartite conference circuit,
The EEPROM 501 of the control unit 5 stores the exchange order in the communication path switch 4.

In FIG. 4, the voice A of the telephone 2a is attenuated to 1/4 and the telephone 2
The time slot allocation when outputting to b is shown. In the figure, each component is exactly the same as in FIG. FIG. 4 shows that when the value of α in the arithmetic circuit 701 in FIG. 2 is 1/2, the telephone 2a is used by continuously using the three-way conference circuit twice.
This is an embodiment in which the level of the voice A is adjusted to 1/4 and sent to the telephone set 2b, which will be described below with reference to the flow chart of FIG.

First, the communication path switch 4 is controlled by the control unit 5 to set up the communication path from steps S1 to S2 of the flow chart shown in FIG. Next, at step S4 in FIG. 5, # the TS ₂ of 2 out highway, tripartite to Yotsute level conference circuit 7 are A / 2 that is adjusted to 1/2 is Notsu # 3 input highway TS Connect ₃ Then, in step S5, TS of # 3 highway
_2, the # 2 input highway silence is assigned TS ₁
Connect.

A / 2 and silence are converted to A / 4 by the three-party conference circuit 7 and output to TS ₄ of the # 3 incoming highway. Step S
By connecting the TS ₂ of the # 1 outgoing highway to which the telephone 2b is assigned at 6, the TS ₄ of the # 3 incoming highway,
Phone 2a voice A / 4 with phone 1 adjusted to 1/4 level
Is sent.

As described above, the case where the sound level is adjusted to 1/4 has been described, but the level can be adjusted to α ⁿ times by repeatedly using the three-way conference circuit n times and performing the calculation as silence. it can.

In this way, it is possible to flexibly adjust the level by repeatedly using the three-party conference circuit a plurality of times. That is, even if the number of subscribers increases, the number of parts and the cost do not increase. Also, there is no variation in the amplification / attenuation characteristics in adjusting the output level.

<Level Adjustment of PB Signal> With reference to FIG. 6, the configuration of the embodiment apparatus for adjusting the level of the PB signal will be described. The difference from the circuit configuration of FIG. 1 is a tone / PB signal generation circuit 9, and the other components are the same as those of the embodiment of FIG. Tone / PB
The signal generation circuit 9 uses various tone signals including silence and PB.
It is a circuit that generates a signal and sends it to the # 2 incoming highway.

Adjust the level of the PB signal PB ₁ to 1/2 (= -3 dB), and
The case of sending to a will be described below according to the flow chart of FIG. From the control unit 5 controls the speech channel switch 4, in step S7, the tripartite conference circuit TS ₁ of the # 2 output highway inputted to 7, the # 2 input highway PB signal PB ₁ is assigned TS ₁ Connect. With Step S8,
# 3 out TS ₁ of the highway, connecting the TS _n of # 2 input highway silence is assigned. PB ₁ and silence are converted to 1/2 PB ₁ by the three-way conference circuit 7 and output to TS ₃ of the # 3 incoming highway. Step S9, station line 3a
# 1 is assigned to TS ₁ of the highway, and # 3
By connecting the incoming highway TS ₃ to the station line 3a,
PB ₁ with the level adjusted to 1/2 is sent out.

The explanation has been given above in the case where the PB signal is adjusted to 1/2 (−3 dB) of PB ₁ and transmitted to the station line. However, when it is necessary to further attenuate the level, the three-way conference circuit 7 is used. Enter # 2
By putting a set of 1/2 PB ₁ and silence on the same time slot of the output highway, # 3 output highway, the time slot two slots after the time slot of the # 3 input highway, Level has been further reduced to 1/2 1
/ 4 PB ₁ is obtained. That is, by using the tripartite conference circuit n times in succession, the level of the PB signal is (1/2) ⁿ (=
It can be adjusted to −3nd B).

In this way, by using the three-party conference circuit, the level of the PB signal can be simplified simply by controlling the setting of the communication path.
And it can be flexibly adjusted. That is, in the key telephone device and the private branch exchange, by effectively utilizing the arithmetic function of the three-party conference circuit of the main device, it is possible to control the setting of the communication path without adding a special circuit for level adjustment. Therefore, it is possible to economically, simply, and flexibly adjust the level of the PB signal of the level for the selection signal to a level that complies with the regulation of the transmission power other than when it is used for the call of the regulation such as the terminal equipment. effective.

In the above embodiment, the memory for storing the set value of the output signal level is the EEPROM, but the battery back-up RAM is stored.
(Random access memory) may also be used, or battery backup is not necessary if it is not necessary to take into consideration that data is stored due to power failure or the like.

Further, in the above embodiment, the level setting instruction is issued from the maintenance switch 8, but in view of the fact that the button telephone can have various functions by the button, the instruction input is made from the button of the telephone. You may

Furthermore, in the above-described embodiment, the arithmetic circuit 701 is composed of an adder or the like, but it may be composed of a ROM forming a table. In this case, assuming that the value of α differs for each set level, multiple types of tables
Must be stored in.

[Effects of the Invention] As described above, the exchange apparatus of the present invention is equivalent to the result of inputting the first and second audio signals and performing addition and level adjustment of the first and second audio signals. A three-party conference circuit that outputs a third audio signal that is used is used. Then, the speech path switch is controlled to supply the inputted fourth audio signal to the three-party conference circuit and a signal for using the three-party conference circuit for level adjustment. I am trying. Therefore, it is possible to adjust the level for each subscriber by utilizing the tripartite conference circuit, and as a result, it is possible to reduce the number of parts and the cost.

[Brief description of drawings]

FIG. 1 is a block diagram of a button telephone device and a private branch exchange of an embodiment relating to level adjustment of voice and audible sound, FIG. 2 is an internal block diagram of a three-party conference circuit in the embodiment of FIG. 1, and FIG. 1 is a flow chart for explaining the embodiment of FIG. 1, FIG. 4 is an illustration of another embodiment of the present invention, FIG. 5 is a flow chart for explaining the embodiment of FIG. 4, and FIG. 6 is a PB signal. FIG. 7 is a circuit configuration diagram of an apparatus for adjusting the level, and FIG. 7 is a control flow chart of the embodiment of FIG. In the figure, 1 ... Main device, 2a, 2b, 2c ... Telephone, 3 ... Line interface, 4 ... Call path switch, 5 ... Control unit, 6 ...
… Audible sound generation circuit, 7 …… Three-party conference circuit, 8 …… Maintenance switch, 9 …… Tone PB signal generation circuit, 501,
705 ... EEPROM, 701 ... arithmetic circuit, 702 ... S / P converter,
703 ... It is a P / S converter.

Claims (1)

[Claims] 1. A speech path switch and a first and a second audio signal are input from an output of the speech path switch, and correspond to the result of adding and level adjusting the first and second audio signals. A three-party conference circuit for outputting a third voice signal to the input of the call path switch, and controlling the call path switch to obtain a level-adjusted fourth voice signal from the input fourth voice signal And supplying the input fourth audio signal to the three-party conference circuit, and supplying a signal for using the three-party conference circuit for level adjustment to the three-party conference circuit. A telephone exchange device characterized by having.