JPS5992662A - Sound signal superposing system - Google Patents

Abstract

PURPOSE:To superpose a sound code economically by superposing plural sound signals one over another without installing plural mixing trunks in a digital exchange. CONSTITUTION:The digital exchange consists of a multiplexing circuit MPX, channel memory SPM, mixing memory MXM, separating circuit DMPX, control part SMC, switch information storage part REG, signal reception and distribution part SRD, and central controller CC. When in-call incoming display service, interrupt call service, conference telephone service, etc., are offered through the digital exchange, a sound signal such as an incoming display tone is stored in a specific address of the memory SPM and a subscriber's voice and various signal tones are superposed in the storage part REG and stored after time slot replacement. This stored signal is sent out from a down highway to each subscriber through the circuit DPMX by using a specific time slot. Thus, the means for superposing the sound signal is provided in a time-division switch, so the need for a mixing trunk is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a digital exchange, and more particularly to an audio signal superimposition method for economical superimposition of audio signals in a digital exchange with simple control.

fb) Technical Background As the services of automatic switchboards have become more diverse, it has become increasingly difficult to use services such as call waiting display service (hereinafter referred to as call waiting service), call waiting service, or conference call service. Opportunities to superimpose other voices or signal tones are increasing.

(C1 Prior Art and Problems FIG. 1 is a diagram showing an example of a conventional voice signal superimposition method in a digital exchange. In FIG. 1, a subscriber A who is provided with the call waiting service
Assume that subscriber B is currently talking to subscriber B via communication paths p1 and p2 in time division switch NW. When another subscriber After making subscriber A listen to the incoming call display tone CT for a short time, communication paths p6, p7, and p8 are further set in the time division switch NW, and communication path p5 is released to allow subscribers A and B to talk. The call continues via the mixed trunk MXT, and the mixed trunk MXT superimposes an incoming call tone 11T on the voice signals of each subscriber A and B to notify the presence of the incoming call. During that time, the ring tone RBT is returned to the subscriber X via the communication path p9 set in the time division switch NW.

When subscriber A hooks up, the central controller CC sets the communication paths plo, pll and 1 in the time division switch NW.
2 is set, subscriber A is connected to subscriber X, and subscriber B is made to listen to the waiting person WT.

As is clear from the above explanation, in the conventional audio signal superimposition method, the arrival tone TIT is sent to subscribers A and B.
A mixed trunk MXT was used to listen to the call overlay. Therefore, multiple mixed trunk MXTs are installed depending on the call volume that requires superimposition of voice signals on the digital exchange.
It is also necessary to provide a mixed trunk MX for subscribers A and B, as well as incoming call display tone CT and incoming call tone IIT.
It is necessary to sequentially set communication paths p3 to p8 connecting to T, and it is also necessary to consider processing when all mixed trunks MXT are busy, which complicates the control of the central control unit CC and increases the load. There were drawbacks.

(d+ Object of the Invention The object of the present invention is to eliminate the drawbacks of the conventional voice signal superimposition method as described above, eliminate the need to install multiple mixed trunks in a digital exchange, and reduce the complexity and burden of control on the central control unit. The object of the present invention is to realize a means for superimposing a plurality of audio signals without causing an increase in audio signals.

te+ Structure of the Invention This object is to provide a digital exchange using a time division switch with means for superimposing a plurality of voice signals in the time division switch, and to superimpose a plurality of voice signals read from a communication path memory in the time division switch. This is achieved by superimposing the signals by the means and then outputting them from the time division switch.

(fl　Embodiments of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing an audio signal superimposition method according to an embodiment of the present invention, FIG. 3 is a diagram showing an example of the configuration of the communication channel memory in FIG. 2, and FIG. FIG. 3 is a diagram showing an example of a memory configuration.

Note that the same reference numerals indicate the same objects throughout the figures.

In FIGS. 2 to 4, the multiplex circuit MPX, channel memory SPM, mixing memory MXM, separation circuit DMPX, control section SMC, switch information storage section REG, and signal reception distribution section SRD constitute a time division switch NW. The voices transmitted by subscribers A and B during a call via the time division switch NW are converted into, for example, 8-bit PCM encoded voice signals (A) and (B), and then sent to the multiplex circuit MPX.
The information is stored at a predetermined address in the speech path memory SPM in the time slots of the up highway.

In addition, at specific addresses in the speech path memory SPM, audio signals (IIT), etc., which are 8-bit PCM encoded various signal tones such as arrival tone IIT, etc., and audio signals (IIT) indicating silent NT are stored.
NT) is stored. The central control unit CC superimposes the voice signal (NT) of the silent NT on the voice signals (A) and (B) of the subscriber A and the subscriber B in the switch information storage unit REG via the signal reception distribution unit SRD. Accumulate instructions for changing time slots. Based on the instructions stored in the switch information storage REG, the control unit SMC extracts the voice signal (B) and silence of the subscriber B from the speech path memory sPM in the time slot corresponding to the subscriber A on the down highway. Sequentially read out the audio signals (NT) of NT, and then read the audio signals (B) from the mixed memo IJ M
The audio signal (B) stored at the address determined by Also, in the time slot corresponding to subscriber B, the voice signals (A) and (NT) of subscriber A and silent NT are sequentially read out from the communication path memory SPM in the same process, and the voice signals (A) and (NT) of subscriber A and silent NT are read out from the mixed memory MXM. and (N
The audio signal stored in the child dress determined by T) (
A) is read out and sent to the time slot corresponding to the subscriber B on the down highway via the separation circuit DMPX. As a result, subscribers A and B receive only the audio signals (B) and (A) sent by their interlocutors. Next subscriber
When an attempt is made to receive a call from subscriber A who is provided with a call-waiting service, the central controller CC makes subscriber A listen to the incoming call display tone CT for a short period of time, and then transmits the switch information via the signal reception distribution unit SRD. @Accumulation REG, subscriber A
Then, an instruction to change the time slots is stored by superimposing the arrival intermediate tone ■IT audio signal (IIT) on the subscriber B's audio signals (A) and (B). Based on the instructions stored in the switch information storage REG, the control unit SMC extracts the subscriber B's voice signal ( B) and the voice signal (IIT) of the arrival tone 11T are sequentially read out, and the voice signals (B) and (TIT) stored in the address determined by the voice signal (B) and (TIT) from the mixed memory MXM are read out. The synthesized audio signal (B) + (I IT) is read out and sent to the time slot corresponding to the subscriber A on the down highway via the separation circuit DMPX. Also, in the time slot corresponding to subscriber B, the voice signal (
A) and (IIT) sequentially, mixed memory MXM
reads the synthesized audio signal (A) + (IIT) of the audio signals (A) and (IIT) stored at the address determined by the audio signals (A) and (IIT),
It is sent to the time slot corresponding to subscriber B on the down highway via the separation circuit DMPX. As a result, subscriber A
and B are the intermediate sounds TI that are attached to the voices sent by the interlocutors.
The superimposed phonetic code of T (B) + (IIT) and (A
) + (I IT) is received.

As is clear from the above description, according to this embodiment, the address of the mixed memory MXM is determined by the two sets of audio signals read out from the speech path memory SPM.

By reading out the synthesized voice signal of the two sets of voice signals stored in There is no need to set up a complicated communication path within the time division switch NW regarding the mixed trunk MXT.

Note that FIGS. 2 to 4 are only one embodiment of the present invention, and for example, the configuration of the time division switch is not limited to that shown in the figures, and instead of superimposing silent NT, a mixed memory may be used. Call path memory SP without going through MXM
Although many other variations are considered, such as sending the vehicle directly from M to the down highway, the effect of the present invention remains the same in either case.

Furthermore, the object of the present invention is not limited to the superimposition of the arrival tone IIT in a call waiting service,
Waiting call service or conference call service, or even 3
Many services are considered for communication, such as services that superimpose more than one type of audio signal, but the effects of the present invention do not change in any case.

(a) Effects of the Invention According to the present invention, voice codes can be processed in the digital exchange without installing a plurality of mixed trunks and without complicating the control and increasing the load on the central control unit. It becomes economically possible to overlap.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a conventional audio signal superimposition method, FIG. 2 is a diagram showing an audio signal superimposition method according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of the configuration of the communication path memory in FIG. 2. The figure shown in FIG. 4 is a diagram showing an example of the configuration of the mixed memory in FIG. 2. In the figure, A, B and is the waiting tone, RBT is the ring tone, NT is the silent tone, MPX is the multiplex circuit, SPM is the channel memory, MXM is the mixed memory, DMPX is the separation circuit, SMC is the control unit, R
EG is a switch information storage unit, SRD is a signal reception distribution unit,
(A), (B), (X), (NT), (B) + (I
IT) indicates a phonetic code. 0 Figure 2 v 3 Figure 4

Claims (1)

[Claims] In a digital exchange using a time-division switch, means for superimposing a plurality of voice signals is provided in the time-division switch, and after the plurality of voice signals consecutively output from the communication path memory in the time-division switch are superimposed by the means, An audio signal superimposition method characterized in that an audio signal is output from the time division switch.