JPS60213158A - Bridge cut off system of digital channel switch - Google Patents

Abstract

PURPOSE:To use only a main time division channel switch without requiring any analog switch by forming secondary time switch holding memories which are equal to the number of channels to be interrupted, and synthesizing the channels specified by said memories through voice synthesis operating circuits. CONSTITUTION:In the time division channel switch provided with a primary side time switch T1, a secondary side time switch T2 and a space switch S connecting between both the time switches, plural primary time switch holding memories CM2 and plural operating circuits for synthesizing voice signals from plural channels specified by the memories CM2 are arranged on the primary side, and the outputs of the operating circuits are sent to a highway on the secondary side. The voice synthesizing operation circuits are used in common under time division mode for respective interruption connection. Therefore, the small number of voice synthesizing operation circuits may be used in common.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a communication path in a digital telephone exchange. In particular, it relates to interrupt connections, such as when interrupting a call to a subscriber who is talking or when adding a tone.

[Description of prior art]

In the conventional system, the above-mentioned interrupt connection was performed by providing an interrupt circuit outside the main time-division channel switch. One of them is the subscriber circuit (LC) as shown in Figure 1.
) The interrupt is performed by an analog switch (ASW) provided on the side. In this case, if multiple interrupt connections occur simultaneously within the same exchange, the scale of the analog switch will increase depending on the traffic. Furthermore, as shown in FIG. 2, for example, a trunk TRK having a plurality of connection terminals a, b, and c is provided to perform an interrupt connection.

In this case, there are disadvantages in that it is necessary to reconnect the communication path to which an interrupt connection is to be made to the trunk, and that the communication path is temporarily cut off during the reconnection.

[Purpose of the invention]

The present invention solves the above-mentioned conventional problems, and does not require an analog switch outside of the main time-division channel switch, has no restrictions on traffic, and requires a lot of switching processing. It is an object of the present invention to provide a method that can reduce the amount of processing, eliminate instantaneous interruptions during reconnection, and be able to cope with future complex exchanges such as digital exchanges and data exchanges.

[Features of the invention]

The present invention originally requires one secondary time switch memory for the time switch on the secondary side, but by providing secondary time switch holding memories equal to the number of interrupts (or the number of voices desired to synthesize), The present invention is characterized in that the speech channel specified by the next time switch holding memory is synthesized by a voice synthesis calculation circuit, and the synthesized voice is outputted to a specified output terminal.

That is, the present invention provides a time division channel switch including a time switch on the negative side, a time switch on the secondary side, and a space switch connecting between the time switch on the secondary side and a space switch connecting between the time switches on the secondary side. A secondary time switch holding memory, an arithmetic circuit for synthesizing audio signals of a plurality of communication channels designated by this memory, and a circuit for sending the output of this arithmetic circuit to a secondary highway. It is characterized by

The speech synthesis calculation circuit used in the present invention is used in common and in a time-sharing manner for each interrupt connection. Therefore, it is advantageous that it is economical to provide only one voice synthesis calculation circuit in common.

Furthermore, since the above-mentioned reconnection is not necessary, even when removing an additional connection to the original connection path, the added part can simply be removed, and the control process is extremely simple.

[Explanation based on examples]

FIG. 3 is an interrupt connection diagram according to an embodiment of the present invention. This figure shows an example in which subscriber A and subscriber B are initially talking, and subscriber C interrupts the call.

In FIG. 3, MDSW is the main time division communication path, and TRK is the trunk circuit.

FIG. 4 is a diagram showing the interrupt connection in more detail. Subscriber A is a subscriber accommodated in TSI on Highway 10. Also, subscriber B is high urchin H'1
42, the subscriber C is a subscriber accommodated in the time slot TS401 of the highway HW2. Subscriber A has been written to a predetermined position (TSI) of the time switch TI on the primary side of the highway HWO with the digitally encoded content (a) at a digital sampling frequency wI (125 μS in this example). This is written in a predetermined position (CI+5) of the time switch T2 on the secondary side of the highway HW2 where the subscriber B is accommodated by the space switch S in the empty channel CH5.

The voice digitally encoded content of subscriber B on the opposite side is also written to time slot TS400 of time switch TI on the primary side of highway 811, empty channel CI+5, and is sent to the time switch on the secondary side via space switch S. T2
This is written to a predetermined position (CH3) in the secondary time switch holding memory CM with a read cycle (125 μs).
The output is output to the output storage position specified in step 2. Subscriber A is in time slot γ)TSI of the highway HWO, and subscriber B is in time slot TS400 of the highway HWI. The digitally coded input contents a and b are output to subscriber A with b being exchanged and a with subscriber B being exchanged, respectively.

A case will be explained in which a third subscriber C interrupts the call between subscribers AB and becomes a champion call.

First, the route by which the audio content C of subscriber C is output to the output side of subscriber A will be explained. A processor (not shown) controlling the call path may interrupt the call path between subscribers AB if subscriber B is connected to channel CH5 of time switch T2 on the secondary side of subscriber A. I know that there is, and furthermore, from Highway HWI to Highway 11WO
selects an empty channel CH2 between them and writes the contents C of the subscriber C to the channel CH2 of the time switch T2 on the secondary side of the highway HWO. At this time, C112, which is the address of the secondary time switch T2, is written into the secondary time switch holding memory CM2', which is provided for interrupt control in parallel with the secondary time switch holding memory CM2. At the same time, "1" is written to the least significant bit of the holding memory CM2. This lower bit is not particularly specified and may be any bit. By doing this, the time slot TSI corresponding to the output of subscriber A is connected to the time switch T2 on the secondary side of the basic connection.
This means that C at position CI2 of time switch T2 on the interrupt secondary side is added to b at position CH5.

Here, the arithmetic circuit performs voice synthesis of b and c according to the sequence of the readout arithmetic time chart shown in FIG. When the own read cycle is nth (in this example, it is "1" because it is the temporary side time switch TSI between highway H)
The interrupt identification bit of holding memory CM2 is read by RF and clock (RF I ), and the selector (SEL)
The path is switched to the output side from the arithmetic circuit (ALII) instead of from the time switch T2 on the secondary side. Arithmetic circuit ＾LU
At the same time, reads b of position CH5 of time switch T2 on the secondary side specified in holding memory CM2, and calculates and combines it with C of digit 1cH2 of time switch T2 on the secondary side where the next interrupt contents are stored. (Fundamental parts in the figure)
). Position C of secondary side time switch T2 Readout of C at 2 is ROn (RO+) (offering par
At the same time as the readout, the data is calculated in the arithmetic circuit ^Lll, and the contents of (b+C) are output to the output position at the clock of the next time slot TSn (TS + ).

Here, the calculation contents are calculated according to the digital coding regulations.

When this cycle ends, the process moves to the next n+1 and the same operation is performed. If there is no interrupt, the interrupt identification bit in the memory CM2 held during the RFn clock is not set (0), so no processing corresponding to the ROn clock is performed and the selector SEL is
is switched to the output side of the time switch T2 on the secondary side, and the contents of the time switch T2 on the secondary side are read out to obtain the time slot TSn. How to use the selector SEL is to directly use the RFn clock to run the arithmetic circuit without placing this selector.
The contents of the secondary side time switch T2 read out to the LU may be used as the output of the secondary side time switch TSn.

The voice synthesis control at the time of an interrupt as described above is the same for the output control units B and C. Further, to cancel the interrupt, it is sufficient to simply rewrite the interrupt identification bit in the holding memory CM2 from "l" to "0".

The speech synthesis calculation circuit ^LU may be one commonly used instead of one for each highway.

Furthermore, although the interrupt connection has been described as one connection, it can be increased using the same control as in 2.3---n. In this case, each time the number of interrupt connections is added to the secondary time switch holding memory CM2, the holding memory changes to CH2' -
------CM2n will be added.

Furthermore, even if a "tone" is mixed in instead of the interrupt connected subscriber C, the same control can be performed.

〔Effect of the invention〕

According to the present invention, when a large number of interrupt connections occur simultaneously, the scale of the analog switch does not increase.

Furthermore, there is no need to perform many connection changes at the time of an interrupt, and instantaneous interruptions do not occur. The present invention does not require consideration of such traffic proportions and is highly adaptable. Furthermore, when canceling an interrupt, the process is quick and simple, as it only requires rewriting the interrupt identification bit from "1" to "0" without requiring the troublesome steps of the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an interrupt connection method using a conventional analog switch. FIG. 2 is a diagram of a conventional interrupt connection system using trunks. FIG. 3 is a schematic diagram of an interrupt connection method according to an embodiment of the present invention. FIG. 4 is a detailed diagram of an interrupt connection method according to an embodiment of the present invention. ,. FIG. 5 is a time chart of the interrupt access method according to the embodiment of the present invention. LC...Subscriber circuit, TRKo...Trunk circuit,
ASW: analog switch, TNT: three-party call trunk, AlB: basic call subscriber, C: interrupt call subscriber, MDSW: main time division call path, TI...・-Next side time switch, S...Space switch, T2...Secondary side time switch, CH2...
・Secondary time switch holding memory, CH2'...Secondary time switch holding memory (for interrupt control), ^LU...
Speech synthesis calculation circuit, SEL...selector, IIWO,
IIWI, HW2...Highway, C1l...
Channel, TS...time slot. Patent Applicant NEC Corporation Representative Patent Attorney Naotaka Ide, ¥) 1 Sumo 2 Garden; ¥) 32

Claims (1)

[Claims] (1) - In a time division channel switch including a time switch on the next side, a time switch on the secondary side, and a space switch connecting between the time switch on the secondary side and the switch between the two, a plurality of two It is characterized by comprising a next time switch holding memory, an arithmetic circuit that synthesizes audio signals of a plurality of call channels specified by this memory, and a circuit that sends the output of this arithmetic circuit to a secondary highway. Interrupt connection method for digital communication path switches.