JPS6142920B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a time division switching network, and more particularly to the configuration of a time division switching network in which leased line terminals are accommodated in a time division exchange by semi-fixed connections.

Generally, telephone subscriber terminals are housed in the nearest exchange, but some telephone subscriber terminals may be housed in remote, out-of-area exchanges. Conventionally, this type of subscriber terminal has been accommodated in an out-of-area exchange using a configuration as shown in FIG. That is, the normal subscriber terminals 10a, 10b in area A are connected to the switched network 14 of area A.
A and normal subscriber terminals 10c and 10d in area B are connected to area B's switched network 14B.
be accommodated in. On the other hand, the out-of-area accommodated subscriber terminal 12 that we are currently focusing on is originally the switched circuit network 14 of area A.
A should be accommodated in the switching network 14B outside the area. Specifically, the terminal 12 bypasses the switching network 14A to reach the transmission terminal equipment 16A, and by exclusively using a specific channel of the multicarrier line 18, it reaches the transmission terminal equipment 16B in area B. . Transmission terminal equipment 1 in area B
At 6B, the dedicated line is branched from the general interoffice trunk line and accommodated on the subscriber side of exchange 14B.

Now, under the situation shown in FIG. 1, consider a case where the conventional electromagnetic mechanical switch 14A is replaced with a time-sharing switch 20A as shown in FIG. 2. In this case, if the multiplex carrier line 18 is a digital multiplex carrier line 18', the transmission terminal device 16A in FIG. 1 is replaced with a digital multiplex trunk interface circuit 22A. the result,
It becomes impossible for the terminal 12 to directly access a specific channel on the multiplex transmission path.

To solve this problem, as shown in Figure 2, the terminal 12
If the terminal 12 is housed in the time division switch 20A and is always connected to a specific dedicated channel of the digital multiplex carrier circuit 18' by a semi-fixed connection, the terminal 12 can be transferred to the switch 14B outside the area in a format equivalent to the conventional method shown in FIG. Can be accommodated.

However, one problem arises here.
Now, assuming that the terminal 12 is a rotary dial telephone, the time division switch 20A transmits dial pulses sent from the terminal 12 to the multiplex transmission line 1 without distortion.
I need to put it on 8'. However, in conventional exchanges with a general configuration, the
The off-hook state, dial pulse, etc. are once received by the subscriber scanning circuit, dial pulse receiving circuit, etc., and after being processed appropriately by the exchange control circuit, the next signal is transmitted as a new inter-office signal based on the result. The device is to be sent to the exchanger of
No subscriber status signals or dial pulses are sent directly to the interoffice relay transmission line. In this case, if the subscriber scanning result is directly sent as an interoffice signal without any processing in the exchange control circuit, in principle, the dial pulse sent from the out-of-area accommodation terminal 12 can be transmitted to the exchange. 14B. However, although it is generally possible for switching control circuits to correctly send level information related to on/off that represents the subscriber status to the relay transmission path, transparency on the time axis with respect to the intermittent on/off time length is is not guaranteed. This problem can be solved by taking an electronic exchange as an example.The exchange control circuit of the electronic exchange is a storage program control device, and the on/off of subscriber status signals is sent to the relay transmission path through software program processing. The transmission time will vary significantly depending on the processing load of other jobs that the processing unit is processing simultaneously, resulting in distortion of the dial pulses to accommodate out-of-area terminals. This results in a situation where the exchange cannot receive correct dial/pulse information.

An object of the present invention is to accurately transmit subscriber status signals to a leased line terminal accommodating exchange without distortion when a type of leased line terminal such as a subscriber terminal accommodated outside an area is relay-connected via a time division exchange. The object of the present invention is to provide a time-division switching network that accommodates leased line terminals by semi-permanently connecting them.

That is, according to the time-division switching network of the present invention, in addition to the main switching network that exchanges and connects only call information, the time-division switch also includes a sub-switching network that exclusively exchanges and connects only subscriber status monitoring signals. The digital multiplex trunk interface device arranges the call information and the corresponding subscriber status monitoring signals in the same channel and sends them to the digital trunk line. A time division switching circuit network is provided which makes it possible to send a monitoring signal to a relay line without distortion.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of this invention.
24-1 and 24-2 are subscriber interface circuits, which supply call current and linking current to subscriber terminals, monitor on/off and hook status of terminals, convert/invert voice information from analog to digital, etc. It has the following functions. 26 is a main switching circuit network for exchanging and connecting digitized call information, and 28 is a control circuit thereof. 30-1 and 30-2 are digital multiplex trunk interface devices that perform unipolar/bipolar conversion of digital signals, frame and
It has functions such as alignment and branching/insertion of monitoring signals corresponding to each multiple channel.

Reference numeral 32 denotes a central control unit that controls the entire exchange operation through storage program control. 34 is for turning on/off the terminal by means of lead wires L ₁ and L ₂ branched from the subscriber interface circuits 24-1 and 24-2.
A scanning circuit 36 scans the hook status and displays the result on the central controller 32, and 36 is a scanning circuit for distributing the trunk line monitoring signal sent from the central controller 32 to a desired channel of a desired digital multiplex trunk line. This is a signal distribution circuit. Although the above configuration blocks have some variability, they are the same as those of a conventional general time division switch.In addition, according to the time division switch network of the present invention, the following block circuits are included. More will be added.

That is, the sub-switching circuit network 38 converts and connects the scanning output from the scanning circuit 34, its control circuit 40,
Whether the monitoring signals sent to the multiplexing and demultiplexing circuit 42 that separates the time-division switched output of the sub-switching circuit network 38 and the digital multiplex trunk line interface devices 30-1 and 30-2 are from the central controller 32 or from the leased line terminal. Selection circuit 44 for selectively selecting whether the
1,44-2 is added.

Next, the operation will be explained with reference to FIG.

First, in the case of the general subscriber terminal 10a, its on/off hook status signals, dial pulse signals, etc. are transmitted by the scanning circuit 34 to the subscriber interface circuits 24-1 and 24-2 through the lead wires _L1 and _L2. , and the results are captured by the central controller 32 . After executing the necessary processing, the central control unit 32 instructs the signal distribution circuit 36 to send out appropriate inter-office signals. The signal distribution circuit 36 sends an inter-office signal based on a command from the central controller 32 to a signal position of a desired channel of a desired multiplex transmission path via lead wires M ₁ and M ₂ .

On the other hand, for leased line terminals 12 that wish to send terminal status signals as they are to the relay path, the scanning results of the scanning circuit 34 are sequentially written into the memory in the sub-switching network 38 in correspondence with the terminal numbers. Here, as an example of the sub-switching circuit network 38, a time switch composed of one stage of memory is assumed. The written scanning result is outputted to the signal insertion position corresponding to the corresponding channel on the trunk line to which the main switching network 26 exchanges the corresponding call information by the switching operation of the sub switching network 38. The digital multiplex trunk interface devices 30-1, 30-2 are read out and corresponded to by the demultiplexing circuit 42.
and inserted into a signal insertion position of a desired digital multiplex trunk interface device. When inserting this signal, the selection circuit 44-
1 and 44-2 are lead wires M ₁ and M ₂ and digital multiplex trunk line interface devices 30-1 and 30;
- 2 on the digital multiplex trunk line, whether the signal to be inserted into the signal insertion position corresponding to each channel is a signal related to general subscribers sent from the central control unit 32, or via the sub-switching network 38. Control is performed to select whether the signal is a raw status signal related to the leased line terminal 12 or not.

The above-mentioned embodiment takes as an example a case in which a time division switch is semi-fixedly connected to an electromagnetic mechanical switch via a digital multiplex relay line.
The same can be achieved in the case where all the stations are time-division exchanges.

As explained above, the time division switching circuit of the present invention is provided with a main switching circuit for exchanging and connecting only call information, and a sub-switching circuit for exclusively exchanging and connecting only subscriber status monitoring signals. The digital multiple trunk line interface device is equipped with a configuration in which call information and corresponding subscriber status monitoring signals are arranged in the same channel and sent to the trunk line, making it possible to easily connect leased line terminals such as those for subscribers accommodated outside the area. A time-division switching network has been realized in which the monitoring signal from the leased line terminal can be sent to the relay line without distortion by accommodating the signals in a semi-fixed connection format.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional switching circuit network showing a method for accommodating subscribers outside the area between electromagnetic mechanical exchanges, and Figure 2 is a semi-fixed connection type of time-sharing exchanges for the conventional example shown in Figure 1. FIG. 3 is a block diagram showing an embodiment of a time division switching network according to the present invention. 10a, 10b, 10c, 10d...General subscriber terminal, 12...Subscriber terminal accommodated outside the area (dedicated line terminal), 14A, 14B...Switching network (exchange), 16A, 16B...Transmission terminal equipment , 18...
...Multiple carrier line, 18'...Digital multiplex carrier line, 20...Time division switching network (exchange), 2
4-1, 24-2... subscriber interface circuit, 26... main switching circuit network, 28... control circuit,
22A, 30-1, 30-2...Digital multiple trunk line interface device, 32...Central control unit, 34...Scanning circuit, 36...Signal distribution circuit,
38... Sub exchange circuit network, 40... Control circuit, 42
...Demultiplexing circuit, 44-1, 44-2...Selection circuit.

Claims (1)

[Claims] 1. A main switching network that exchanges and connects only call information, a sub-switching network that connects and exchanges only subscriber status monitoring signals, and a connection that corresponds to the call information from the main switching network and the sub-switching network. and a digital multiplex trunk line interface device for arranging user monitoring signals in the same channel and transmitting them to a digital multiplex trunk line.