JP2809244B2 - Emergency line connection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency line connection system and, more particularly, to a subscriber line side device for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplex signal and a central office. The present invention relates to an emergency line connection system used when a failure occurs in a digital carrier line in a remote digital subscriber line carrier device connected to a connected digital carrier line.

[0002]

2. Description of the Related Art The conventional emergency line connection system is limited to a device having a switching function as implemented by a remote switch or the like.

[0003]

However, since the conventional emergency circuit connection system is realized by a device having a switching function such as a remote switch, it is large-scale (at least several thousand lines) and expensive. However, there is a drawback that the method cannot be applied to a small-sized subscriber line carrier.

[0004] In view of the above drawbacks, the technical problem of the present invention is to connect a subscriber multiplex signal output from a subscriber line side device to an emergency line when a failure occurs in a carrier line.
An object of the present invention is to provide a central office with an emergency line connection system which can be performed by a digital subscriber line carrier at a remote place.

[0005]

According to the present invention, there is provided a method for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplex signal (1) between a subscriber line side device and a digital carrier line. , Wherein a time slot of a subscriber multiplex signal from the subscriber line side device is exchanged according to a predetermined exchange rule, and the time slot exchanged signal is converted to a line multiplex signal ( In the emergency line connection system used in the digital subscriber line carrier having a transmission switch (6) for sending out to the digital carrier line as 61), when a failure occurs in the digital carrier line, a signal from the subscriber line side device is transmitted. Detects off-hook time slots of subscriber terminals as off-hook time slots from subscriber multiplexed signals Off-hook state time slot detecting means (2), and a time slot number of the off-hook state time slot which is connected to the off-hook state time slot detecting means and detected by the off-hook state time slot detecting means is stored as a storage time slot number. Time slot number storage means (3, 4)
Replacing the time slot of the subscriber multiplex signal, which is connected to the transmission switch and the time slot number storage means and is indicated by the storage time slot number, with the time slot of the subscriber multiplex signal for the emergency line. Switch control means (5) for causing the transmission switch to perform the operation, and means (8) for transmitting the output of the transmission switch to the subscriber line side device only when a failure occurs in the digital carrier line. An emergency circuit connection method characterized by comprising:

Further, according to the present invention, a digital line connected between a subscriber line side device for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplex signal (1) and a digital carrier line. A subscriber line carrier device, wherein a time slot of a subscriber multiplex signal from the subscriber line side device is replaced according to a predetermined replacement rule, and the time slot replaced signal is converted to a line multiplex signal (61).
In the emergency line connection method used in the digital subscriber line carrier having a transmission switch (6) for sending out to the digital carrier line, when a failure occurs in the digital carrier line, the subscriber from the subscriber line side device receives An activation signal detector (2) for detecting, as an activation signal, a time slot in which the subscriber terminal is off-hook from the multiplexed signal, and a time for generating a multiplexed time slot number in synchronization with the subscriber multiplexed signal. A slot number generator (3), connected to the activation signal detector and the time slot number generator, each time the activation signal detector generates an activation signal, the time slot number generator A queuing circuit (4) for sequentially storing the generated time slot numbers and outputting the stored time slot numbers in the storage order; The transmission switch, which is connected to the transmission switch and the queuing circuit, replaces a time slot of the subscriber multiplex signal indicated by the storage time slot number with a time slot for the emergency line of the subscriber multiplex signal. Control circuit for switch (5)
And means (8) for sending the output of the transmission switch to the subscriber line side device only when a failure occurs in the digital carrier line.

[0007]

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

FIG. 1 shows a digital subscriber line carrier which implements an emergency circuit connection system according to one embodiment of the present invention. FIG. 2 is a tyro chart showing the operation of FIG.
The digital subscriber line carrier shown in FIG. 1 includes a subscriber line side device (not shown) for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplex signal 1, and a digital carrier line (not shown). (Not shown). As shown in FIG. 2A, the time slot of the subscriber multiplex signal 1 has time slots A, B, C, and D for telephone subscriber lines and a time slot E for an emergency line. This digital subscriber line carrier has a transmission time division switch 6, a reception time division switch 7, and a control circuit 5.

As is well known, when the digital carrier line is normal, the control circuit 5 supplies a time slot of the subscriber multiplexed signal 1 from the subscriber line side device (see FIG. 2 (a), A, B, C, D, and E)
Are transmitted in accordance with a predetermined switching rule, and a transmission control address 51 is given to the transmission time division switch 6 so that the signal whose time slot has been replaced is transmitted as a line multiplexed signal 61 to the digital carrier line. The line multiplexed signal 61 has C, A,
E, D and B have time slots in this order. At the same time, when the digital carrier line is normal, the control circuit 5 sets the reception time division switch 7 to the time slot of the line multiplexed signal 10 from the digital carrier line (C, C in FIG. 2D).
A, E, D, and B) are switched so that the time slots (A, B, C, D, and E in FIG. 2E) of the subscriber multiplex signal 71 are obtained. Is transmitted to the reception time division switch 7 in order to cause the selection circuit 8 to transmit the reception control address 52.

When the digital carrier line is normal, the selection circuit 8 sends the subscriber multiplex signal 71 to an output terminal 81 connected to the subscriber line side device.

An emergency circuit connection system according to one embodiment of the present invention comprises a start signal detector 2 and a time slot number generator 3.
And a queuing circuit 4.

When a failure occurs in the digital carrier line, the activation signal detector 2 detects, from the subscriber multiplexed signal 1, a time slot in which the telephone (subscriber terminal) is off-hook, and indicates the time slot. An activation signal (off-hook time slot portion is "0") 21 is output.

The time slot number generator 3 synchronizes with the subscriber multiplex signal 1 and outputs a binary number 31 representing the time slot number.

Each time the activation signal detector 2 generates the activation signal 21, the queuing circuit 4 outputs the time slot number output 31 generated by the time slot number generator 3 at that time.
Are sequentially stored, and the time slot number output 41 is output in the storage order.

When the digital carrier line becomes faulty and the transmission / reception of the subscriber's signal with the central exchange becomes impossible, the control circuit 5 provides a carrier line output 61 shown in FIG. As shown in FIG. 2A, for example, if it is detected that the telephone is off-hook from the time slot A for the telephone subscriber line in FIG. 2A, the time slot A and the time slot E for the emergency line are The transmission control address 51 is output to the transmission time division switch 6 so that the replaced line multiplex signal is obtained as the carrier line output 61 'in FIG.

When a failure occurs in the digital carrier line, the selection circuit 8 outputs the line multiplexed signal output 61 obtained as the carrier line output 61 'in FIG. The data is transmitted to an output terminal 81 connected to the subscriber line side device.

In this way, when a subscriber using the time slot A for a telephone subscriber line goes off-hook in a state where a fault has occurred in the digital carrier line, for example, the off-hook telephone subscriber line is taken off. Connects to the emergency line, the emergency line is called, the emergency line is connected to the off-hook telephone subscriber, and a call can be made.

[0018]

As described above, according to the present invention, the off-hook subscriber signal is connected to the emergency line by the transmission switch. Therefore, when a failure occurs in the digital carrier line, the subscriber line side device is used. Has the effect that the subscriber multiplexed signal output by the digital subscriber line can be connected to the emergency line by a digital subscriber line carrier remote from the central office.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a time chart of each part of the embodiment shown in FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 subscriber multiplexed signal 2 start signal detector 3 time slot number generator 4 queuing circuit 5 control circuit 6 transmission time division switch 7 reception time division switch 8 selection circuit

Claims (2)

(57) [Claims] A digital subscriber line carrier connected between a digital line and a subscriber line side device for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplexed signal (1). Wherein a time slot of a subscriber multiplex signal from the subscriber line side device is exchanged according to a predetermined exchange rule, and the time slot exchanged signal is transmitted to a digital carrier line as a line multiplex signal (61). In the emergency line connection system used in the digital subscriber line carrier having a switch (6), when a failure occurs in a digital carrier line, a subscriber terminal is determined from a subscriber multiplex signal from the subscriber line side device. Off-hook time slot that detects off-hook time slot as off-hook time slot A time slot number storage connected to the detection means (2) and the off-hook state time slot detection means, and storing a time slot number of the off-hook state time slot detected by the off-hook state time slot detection means as a storage time slot number; Means (3, 4), connected to the transmission switch and the time slot number storage means, for the time slot of the subscriber multiplex signal indicated by the storage time slot number and for the emergency line of the subscriber multiplex signal. Replacement with the time slot of
Transmission switch control means for causing the transmission switch to perform, and means for transmitting an output of the transmission switch to the subscriber line side device only when a failure occurs in the digital carrier line. Emergency circuit connection method. 2. A digital subscriber line carrier connected between a subscriber line side device for multiplexing a plurality of telephone subscriber line and emergency line signals as a subscriber multiplex signal (1) and a digital carrier line. Wherein a time slot of a subscriber multiplex signal from the subscriber line side device is exchanged according to a predetermined exchange rule, and the time slot exchanged signal is transmitted to a digital carrier line as a line multiplex signal (61). In the emergency line connection system used in the digital subscriber line carrier having a switch (6), when a failure occurs in a digital carrier line, a subscriber terminal is determined from a subscriber multiplex signal from the subscriber line side device. An activation signal detector (2) for detecting an off-hook time slot as an activation signal; And, time slot number generator for generating a multiplexed time slot number (3)
And connected to the activation signal detector and the time slot number generator, each time the activation signal detector generates an activation signal, the time slot number generated by the time slot number generator at that time. A queuing circuit for sequentially storing and outputting the storage time slot numbers in the storage order (4)
Replacing the time slot of the emergency multiplex signal of the subscriber multiplex signal with the time slot of the subscriber multiplex signal, which is connected to the transmission switch and the queue circuit and is indicated by the storage time slot number; A control circuit (5) for causing the transmission switch to perform, and means (8) for transmitting an output of the transmission switch to the subscriber line side device only when a failure occurs in the digital carrier line. Emergency line connection method.