JPS6211557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to time division exchanges, and more particularly to improvements in leased line terminals.

Telephone subscribers are generally accommodated at the nearest exchange, but some telephone subscribers may be accommodated at a remote, out-of-area exchange, and this is called a foreign exchange.

FIG. 1 shows a conventional time division switch with out-of-area accommodation. FIG. 1A shows out-of-area accommodation in an electromagnetic exchange. In FIG. 1A, subscriber 1 is accommodated in exchange 4, which is connected to transmission terminal equipment 6. This transmission terminal equipment 6
is connected to a relay exchange 5 via a multiplex carrier line 11 and a transmission terminal device 7, and a transmission terminal device 8 connected to this relay exchange switch 5 is connected to the transmission terminal device 7. The transmission terminal device 8
is connected to an exchange 10 via a multiplex carrier line 11 and a transmission terminal equipment 9, and this exchange 6 accommodates the subscriber 2. On the other hand, the subscriber 3 accommodated outside the area bypasses the exchange 4 and connects to the transmission terminal device 6 on the exchange 4 side. And subscriber 3
The signal reaches the transmission terminal device 7 by exclusively using a specific channel of the multiplex carrier line 11 between the transmission terminal station 6 and the transmission terminal device 7 on the relay exchange 5 side. In this case, the line of the transmission terminal device 7 branches from the general inter-office trunk line, bypasses the relay exchange 5, and passes through the transmission terminal device 8, the multiplex carrier line 11, and the transmission terminal device 9 again to the exchange 10. is accommodated by subscriber 2.

FIG. 1B shows a case where the electromagnetic mechanical exchange shown in FIG. 1A is replaced with a time-sharing relay exchange. In FIG. 1B, the same parts as in FIG. 1A are denoted by the same reference numerals, and the explanation thereof will be omitted. The transmission terminal device 6 is connected to a relay exchange 14 via a digital multiplex transmission line interface circuit 12 by a multiplex carrier line 11 which is a digital multiplex carrier line,
This trunk exchange 14 is connected to the multiplex carrier line 9 via a digital multiplex transmission line interface circuit 13 and a multiplex carrier line 11 which is a digital multiplex carrier line.

In such a time-division trunk exchange, if the multiplex carrier line 11 is a digital multiplex carrier line, the transmission terminal devices 7 and 8 in FIG.
Replaced by 3. Therefore, it is no longer possible to branch the dedicated line for the subscriber 3 at the relay exchange 5 and bypass the multicarrier interface circuit 12, as in the past. Therefore, in order to solve this problem, the subscriber 3
If the dedicated line for the digital multiplex transmission line 11 is accommodated as is in the relay exchange 14 and connected to the specific dedicated channel of the digital multiplex transmission line 11 through a semi-fixed connection, the subscriber 3 can be connected to the exchange 1 in a format equivalent to the conventional system shown in FIG. 1A.
0 can be accommodated outside the area.

However, if the subscriber 3 has a rotary dial telephone, the relay exchange 14 relays the dial pulse sent from the subscriber and arrives via the multiplex transmission line 11 without distortion, and returns it to the multiplex transmission line. 11
You need to put it on. Regarding this point,
In a conventional general trunk exchange, changes in line signals related to subscriber terminal status (on/off hook status) and dial pulses, etc., which arrive via multiplex transmission lines, are once received by the exchange control circuit. Then, after being processed by the exchange control circuit, it is sent to the next exchange as a new inter-office signal based on the result, so subscriber status signals or dial pulses, etc. are sent directly to the inter-office relay transmission line. never be done. In this case, if the scanning results of the line signals arranged on the multiplex transmission path are sent as they are as inter-office signals without any processing in the exchange control circuit, in principle, the subscribers accommodated outside the area can 3 can be transmitted to the exchange 10. However, in this case, in general, even if the exchange control circuit can correctly relay the level information regarding the on/off of the line signal to the relay transmission, transparency on the time axis with respect to the intermittent on/off time length is not guaranteed. . In an electronic exchange, the exchange control circuit is
It is a storage program control device, and the on/off of line signals related to the status of the subscriber terminal and dial pulses etc. mentioned above are relayed to the relay transmission path through software program processing, and the processor processes them simultaneously. Since the transmission time varies greatly depending on the processing load of the operator, the dial pulses are distorted and the exchange 10 may not be able to receive correct dial pulse information.

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a time-division exchange in which a leased line of a leased line terminal can be semi-fixedly connected to a trunk exchange.

The time division switch of the present invention is connected to a main switching network for exchanging digitized call information; one end is connected to a first digital multiplex line, the other end is connected to the main switching network, a first interface circuit that branches supervisory signals received from one digital multiplex line; a sub-switching circuit network that exchanges and connects specific supervisory signals among the supervisory signals branched by the first interface circuit; ; one end is connected to the main switching network, the other end is connected to a second digital multiplex, and the corresponding call information is exchanged in the main switching network; and a second interface circuit for inserting into the channel a monitoring signal corresponding to the switching operation of the sub-switching network.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a block diagram, in which digital multiplex trunk interface circuits 21a and 21b connected to digital multiplex trunks are connected to a main switching circuit network 2 for exchanging and connecting digitized call information.
2, and this main switching circuit network 22 includes digital multiplex trunk interface circuits 23a,
23b and a demultiplexing circuit 24 are connected. The multiple trunk line interface circuit 21
a, 21b and multiple trunk line interface circuits 23a, 23b have functions such as unipolar/bipolar conversion of digital signals, frame alignment, branching/insertion of monitoring signals corresponding to each multichannel, etc. Ace circuits 21a and 21b are receiving side circuits and digital multiplex trunk interface circuits 23a and 23.
b is a transmitting circuit. The digital multiplex trunk interface circuits 21a, 21b are connected to a scanning circuit 26 via lead wires 25a, 25b, and the scanning circuit 26 is connected to the main switching circuit 22.
A sub-switch network 27 and a central control unit 28, which controls the entire switching operation by storage program control, are connected. A control circuit 29 and a multiplexing/demultiplexing circuit 30 are connected to the sub-switching circuit network 27, and a binary selection circuit 3 is connected to the multiplexing/demultiplexing circuit 30.
1a and 31b are connected. These alternative circuits 31a, 31b are connected to lead wires 32a, 32b.
via the multiple trunk interface circuit 2
3a and 23b, 33 is the central control unit 28
This circuit distributes the trunk line monitoring signal sent from the digital multiplex trunk line to a desired channel of a desired digital multiplex trunk line.

In the time division exchange according to the present invention having the above configuration, in the case of a general call, the monitoring signal, dial, pulse signal, etc. related to the call are obtained by periodically scanning the lead wires 25a and 25b in the scanning circuit 26. The results are imported into central controller 28. After performing the necessary processing, the central control unit 28 instructs the control circuit 29 to send out a monitoring signal corresponding to the next exchange. This control circuit 29 sends out the monitoring signal to the signal position of a desired channel of a desired multiplex transmission path via lead wires 32a and 32b.

On the other hand, if the monitoring signal is for a leased line and is to be sent as is to the relay path, the scanning results of the scanning circuit 26 are sequentially written into the memory in the sub-switching circuit network 27 corresponding to the channel numbers, and the sub-switching As the configuration of the circuit network 27, a time switch consisting of one stage of memory is assumed. The scan result written in this way is outputted to the signal insertion position corresponding to the corresponding channel on the trunk line to which the corresponding call information is exchanged and connected in the main switching circuit network 22 by the switching operation of the sub switching circuit network 27. . This output is distributed by the demultiplexing circuit 30 to the digital multiplex trunk interface circuits 23a and 23b, and is inserted into the signal insertion position of the desired digital multiplex trunk interface circuit. Further, the alternative circuits 31a and 31b are connected to the lead wire 32.
a, 32b and the digital multiplex trunk line interface circuits 23a, 23b into the signal insertion positions corresponding to each channel on the digital multiplex trunk line, are the signals related to general calls sent from the central control unit 28 or the sub-switching circuits? It is determined whether the signal is a distortion-free status signal related to the dedicated line via the network 27.

As explained above, the present invention adds a sub-switching circuit network to the main switching circuit network for exchanging monitoring signals related to the leased line without distortion, so that the digital leased line can be accommodated in a semi-fixed tangential format. This has the effect of relaying monitoring signals related to lines without distortion.

[Brief explanation of the drawing]

FIG. 1A is an explanatory diagram of the conventional accommodation format of a time-division exchange for out-of-area subscribers, FIG. 1B is an explanatory diagram of the semi-fixed connection format of the conventional time-division exchange, and FIG. FIG. 2 is an explanatory diagram of a connection format of a split exchange. 21a, 21b, 23a, 23b...Digital multiple trunk line interface circuit, 22...Main switching circuit network, 26...Scanning circuit, 27...Sub switching circuit network, 28...Central control unit, 29...Control Circuit, 30... Demultiplexing circuit, 31a, 31b...
Binary choice circuit.

Claims (1)

[Scope of Claims] 1. A main switching circuit network for exchanging and connecting digitized call information; one end connected to a first digital multiplex line;
a first interface circuit whose other end is connected to the main switching circuit network and branches a supervisory signal received from the first digital multiplex line; and a supervisory signal branched by the first interface circuit. a sub-switched circuit network that exchanges and connects specific monitoring signals of the main switching circuit; a second interface circuit for inserting a monitoring signal corresponding to the switching operation of the sub-switching network into a corresponding channel on the second digital multiplex line that is switched-connected; switch.