JPS61224592A - Channel switching control system - Google Patents

Abstract

PURPOSE:To prevent the momentary false connecting state of a subscriber's line by providing a prescribed time between a disconnection and a connection within a switching operation in every station. CONSTITUTION:In each channel switching equipment 2, the control circuit 41 of a driving part 4 disconnects, for the first, a channel 5 which terminates its use based upon a simultaneous command from a control device 7 and after the specified time T passed on completion of the disconnecting process, controls a channel disconnection driving circuit 42 and a channel connection driving circuit 43 so as to start a connecting process for the connection of a channel that starts to use. The specified time T is set as follows. Namely, it is set as a sum of required command sending time to all of the channel switching equipment 2 from the control device 7 and a maximum time out of required disconnection processing time in every channel switching equipment 2. Therefore, in a certain station, at the time when the channel 5 that starts to use is connected, other channels are disconnected without fail and so the false connecting state does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a line switching method when a communication line is configured using a changeover switch device.

[Conventional technology]

In teleconference services, etc., the amount of information in the signal is larger than that of telephone calls, and a dedicated teleconference line is generally used.In order to make effective use of the line and to switch the connection destination, the line is connected within the network. A changeover switch device is used, and the system configuration is such that the switch is switched in a timely manner in response to a subscriber's application (connection request).

In the case of such advanced services, in order to reliably connect subscribers at both terminals and provide services at the required time, it is necessary to
A system is in place in which line usage is reserved and line switching is centrally managed by a central control device.

[Problem that the invention seeks to solve]

In this type of system, a simultaneous command from a control device that centrally manages line disconnection and connections is sent to each line switching device to simultaneously disconnect the service line that will be terminated and connect the line that will start a new service. It will be done.

FIG. 3 shows a system configuration for implementing such a conventional line switching control method. For convenience of explanation, two stations (station A and station B) among the plurality of stations will be explained.

Each subscriber A,, A2...A1 is connected to the A station, and the B
The station has each subscriber B1. B2...B are connected, and it is assumed that the network consists of only one line, line 1, between the A station and the B station.

The A station and the B station each have a line changeover switch device 2A,
2B, and each switch device has a switch section 3A.
, 3. and a drive unit 4A that drives each of these switch units,
4. It has Each switch unit 3A, 3a is connected to each subscriber of its own station and line 1.5 (5 indicates a line other than line 1), and is composed of a plurality of switch points arranged in a matrix. ing. Each drive unit 4A for A station and B station.

4B is connected to a central control device 7 via a control line 6, and based on commands from the control device, it scans all the switch points arranged in a matrix of line switching devices to disconnect the subscriber. , make the connection.

In such a system, when the service between the subscriber A1 of the A station and the subscriber Bh of the B station is terminated and the service is newly started between the subscriber A1 of the A station and the subscriber 81 of the B station, the control device 7 is a simultaneous command to A station.

By controlling the drive units 4A and 4g of station B, the switch unit 3A of station A disconnects subscriber A1 from line 1 and connects subscriber A, and in station B, subscriber B... and connect subscriber B1. In this case, the control device 7 controls a large number of line switching devices, and there is a time lag in sending out the simultaneous commands. Also, the number of disconnection points in the line changeover switch equipment at each station.

Due to the difference in the number of connection points, the time at which each subscriber receives control differs.

This will be explained with reference to FIG. Figure 4 (A) is A
It shows the time when the control device 7 sends commands to the station and the B station. A command is sent to the A station at time t, and a command is sent to the B station at a later time t2. Figure 4 (B
) indicates the time when the subscribers of stations A and B are controlled by such a command. At station A, upon receiving a command from the control device 7 at time t1, the drive unit 4A performs a disconnection process for the switch unit 3A from time t to t12. As a result, subscriber A1 is disconnected at time t11. Subsequently, the drive unit 4A performs connection processing of the switch unit 3A from time t1□ to t1
Do this until 4. As a result, subscriber A is connected at time t13.

On the other hand, when the B station receives a command from the control device 7 at time t2, which is delayed from time t1, the drive section 4B performs a disconnection process on the switch section 3B from time t2 to t22. As a result, subscriber B is disconnected at time t21. Subsequently, the drive unit 4R performs connection processing for the switch unit 3B from time t22 to t24. As a result, subscriber B at time t2s
1 is connected to 0 or more such that subscriber A1 of station A
and subscriber B of station B. The service between them ends, and the service for subscriber A of station A and subscriber B1 of station B starts. However, in the conventional line switching control method as described above, since both services share line l, the time t13 to t2
Until 1, subscriber 〇 and subscriber B, . . . are connected, resulting in an erroneous connection state. As described above, the conventional line switching control system has the drawback that an erroneous connection state occurs during switching. In particular, in teleconference services and the like, since the amount of information is large, instantaneous erroneous connection states cannot be tolerated.

[Means for solving problems]

An object of the present invention is to provide a line switching control system that does not cause erroneous connections.

The present invention provides a system in which a communication line in a communication line network connecting a plurality of stations to which each subscriber is connected and a communication partner subscriber is controlled by a control device that centrally manages line disconnection and connection, and each station In a line switching control method in which switching is performed by a line switching device equipped with a line switching device, the line switching device that receives a simultaneous switching command from the control device first disconnects the lines that are no longer in use, and then at least disconnects all the lines from the control device. After a certain period of time, which is the sum of the time required to send commands to the changeover switch device and the maximum time required for disconnection processing at each line changeover switch device, has elapsed, the line to be used is connected. It is characterized by

〔Example〕

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

FIG. 1 is a system configuration diagram for explaining one embodiment of the present invention. In the figure, the same elements as in FIG. 3 are designated by the same numbers. The driving units 4A and 4B of the A station and the B station receive the simultaneous switching order from the central control device 7, and control circuits 41A and 41 divide it into disconnected line information and connected line information.
B, and the switch unit 3A, which is controlled by the disconnection line information.
3. A line disconnection drive circuit 42 disconnects the corresponding switch point of
A, 42.1, and a line connection drive circuit 43A that is controlled by the connection line information and connects the corresponding switch points of the switch units 3A and 3a.

43, and has. Although stations A and B have been described as a representative example, the structure of the line changeover switch device of other stations is also similar.

In each line changeover switch device, the control circuit of the drive section first disconnects the line to be discontinued based on a simultaneous command from the control device 7, and after a certain period of time (T) has elapsed after the disconnection process is completed. , controls the line disconnection drive circuit and the line connection drive circuit to start connection processing for connection of the line to be used. The fixed time T is determined as follows. That is, the fixed time T is the sum of the time required for sending a command from the control device to all the line changeover switch devices and the maximum time required for disconnection processing in each line changeover switch device. Therefore, at the time the line is connected to start using the station,
Other lines are always disconnected and no erroneous connections occur.

The operation when switching from the service between subscriber A1 of station A and subscriber 89 of station B in FIG. 1 to the service of subscriber A and subscriber B1 will be explained with reference to the timing diagram of FIG. do. Note that FIG. 2(A) shows the times when commands are sent from the control device 7 to stations A and B, and FIG. 2(B) shows the times when subscribers are disconnected and connected. When a switching command is sent from the control device 7 to the A station at time t1, the control circuit 41A of the A station divides the received switching command into disconnection line information and connection line information.
A line disconnection drive circuit 42A and a line connection drive circuit 4, respectively.
Enter in 3A.

On the other hand, time 1. B from the control device 7 at a later time t.
When the switching command is sent to the station, the control circuit 41B of the B station divides the received switching command into disconnection line information and connection line information, and sends them to a line disconnection drive circuit 42 and a line connection drive circuit 43 . Enter. At station A, time 1. Later time t11
Subscriber A+ is disconnected at station B, and at time L after time t2, subscriber A+ is disconnected.
Subscriber B at 21. is disconnected. At this point, line 1
Both stations A and B are open.

After the above-mentioned fixed time T has elapsed from the time t12 when the disconnection processing of the switch section 3A was completed due to the disconnection of the subscriber A1 in the A station, the switch section 3. Connection processing is performed at t14, and the subscriber is connected at time t14. At this point, subscriber B9 has already been disconnected on the B station side, and therefore no erroneous connection occurs at this point unlike in the conventional system.

On the other hand, after a certain period of time T has elapsed from the time t22 when the disconnection process of the switch unit 3B is completed due to the disconnection of the subscriber B7 at the B station, the connection process is performed at the switch unit 3B from time t23, and at time t24, the subscriber BI is connected. At this point, subscriber B1 of station A and subscriber B1 of station B are connected.

In the above embodiment, the fixed time T is defined as the sum of the time required for sending commands from the control device to all line changeover devices and the maximum time required for disconnection processing in each line changeover switch. However, by setting such a time, the delay time for the service can be minimized. Although the fixed time T can be selected to be larger than the sum, in this case, the delay time for the service becomes large.

〔Effect of the invention〕

As explained above, according to the present invention, line disconnection and connection of communication lines in a communication line network connecting a plurality of stations to which each subscriber is connected and the communication destination subscriber are centrally managed. In the line switching control method, which is controlled by a control device and switched by a line changeover switch device provided at each station, a predetermined time is provided between disconnection and connection during the switching operation at each station. This has the effect of preventing even momentary erroneous connections.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram for explaining an embodiment of the present invention. FIG. 2 is a timing diagram for explaining the embodiment of FIG. 1. FIG. 3 is an example of a conventional line switching control method. FIG. 4 is a timing diagram explaining the system shown in FIG. 3. 1.5...Line 2A, 2. ...Line changeover switch device 3A, 3.
... Switch parts 4A, 4m ... Drive part 6 ... Control line 7 ... Control device 41A, 41s ... Control circuit 42A, 42. ... line disconnection drive circuit 43A,
43B...Line connection drive circuit agent Patent attorney
Yoshiyuki Iwasa Figure 1 v1 # Notification 16 fingers -? At the time of crawling out t1 (B) At the time of command continuous output of the A station control layer 1 in Fig. 2 t1 (B)

Claims (1)

[Claims] (1) A communication line in a communication line network connecting multiple stations to which each subscriber is connected and the subscriber at the other end of the communication is controlled by a control device that centrally manages disconnection and connection of the line, and each station In a line switching control method in which switching is performed by a line switching device, the line switching device receives a simultaneous switching command from the control device, first disconnects the lines that are no longer in use, and then at least switches all the lines from the control device. Connection of a line to be used is performed after a certain period of time, which is the sum of the time required to send commands to the switch device and the maximum time required for disconnection processing at each line changeover switch device, has elapsed. A line switching control method featuring: