JP2000134363A - Terminal changeover system for line changeover device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid useless installation investment by sequentially transmitting a switching signal till a center connects to a corresponding terminal among different terminals of a called shop every time a center side modem detects a dial tone so as to eliminate the need for a line changeover device at the center side. SOLUTION: A line changeover device 22 of each shop 21 is provided with a function of sending a dial tone to a caller after receiving an incoming call and a function of sending a switching signal is provided to a modem 13 of a center 10 when detecting the dial tone. Thus, the modem 13 of the center 10 detects the arrival of a call to the line changeover device 22 and transmits the switching signal to the device 22 automatically. Thus, setting of a switching signal wait time is selected to be a time from detection of the dial tone by the modem 13 till the transmission of the switching signal from the modem 13. Even when many unspecified number of telephone sets make dialing to a telephone set connecting to the line changeover device 22 of each shop 21, an impression of poor connection is surely reduced and giving-up of a call due to becoming tired of waiting is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone line, facsimile (FAX),
The present invention relates to a switching method of a line switching device for switching and using one or more terminals, and more particularly to an improvement in a terminal switching method of a line switching device in which a plurality of terminals are branch-connected.

[0002]

2. Description of the Related Art FIG. 1 is a schematic diagram showing an example of the overall configuration of a system to which the present invention is applied. 1, 10 is a center, 11 is an input device, 12 is a control unit, 13 is a plurality of modems, 20 is a telephone network, 21 is a plurality of stores 21-1 to 21-21.
-N, 22 are provided in each store and have telephones 26, FAX2
3, a line switching device for switching the modem 24; and 25, a data processing device.

The system shown in FIG. 1 transmits different kinds of information from a center 10 to each branch or each store 21 via a public telephone line (telephone network) 20. The use of these terminals has been switched to reduce the cost of introducing new telephone lines and monthly fees. A plurality of different types of terminals are branched and connected to the line switching device 22 of each store, and the same connection terminal is provided with the same 1- to 4-digit dial number as the telephone number (dial number) of the telephone operator. When the line switching device 22 receives a call, the terminal is sequentially switched to the terminal of the dial number, and the telephone 26, FAX 23 or modem 24 connected to the terminal is called.

Here, an unspecified number of telephones 15
The case will be described. FIG. 2 is an explanatory diagram of a telephone from an unspecified number of telephones. In this case, telephone 1
5 cannot send a switching signal to the line switching device 22 of the communication partner, the waiting time of the switching signal is set in advance in the line switching device 22, and the switching signal is received within the set time. If not, a timeout occurs and the telephone 26 is automatically called.

Returning to FIG. 1, for example, in the case of FAX,
Currently, many devices having an automatic switching function are used, and switching is performed by transmitting a CNG signal. Then, what is problematic is the timing at which the switching signal is transmitted from the modem 13 on the center 10 side. In the case of a telephone line, a connection delay time occurs. The connection delay time is the time from when the calling party finishes dialing until the bell of the called party's telephone rings, the distance to the other party's telephone and the performance of the telephone network exchange. Of course, the time is different. It is about 1 second to 2 seconds in a short place, but it may take about 15 seconds in a long place, and may take 20 seconds or more in a dial-in or the like directly connected to an extension via a private branch exchange (PBX). Further, even when a call is made from the same place to the same place, the connection delay time may vary depending on the connection route of the telephone network or the congestion (use) of the line.

Therefore, conventionally, when switching between the modem 23 and the FAX 24, the switching signal waiting time is lengthened or the actual connection delay time is measured, and the modem 1 on the center 10 side is switched.
In No. 3, the pause time after the end of the dialing (the idle time from the end of the dialing to the transmission of the disconnection signal) is set.

[0007]

The problem here is that when switching between the telephone set 26 and the modem 24, when making a call from an unspecified number of telephone sets 15 to the telephone set 26 connected to the line switching unit 22, Since the switching waiting time of the line switching device 22 causes the caller's telephone to wait, it is ideal to minimize the switching waiting time as much as possible. However, if this time is too short, the switching signal cannot be sent within the set time, and a timeout occurs and an erroneous connection such as connection to the telephone 26 occurs.

In order to avoid an erroneous connection, as shown in FIG. 3, a line switching device 14 is also provided on the center 10 'side, and a connection operation is performed by mutual switching devices on the transmission side and the reception side. In the case of a configuration in which a plurality of lines are accommodated in the center 10 'and data is simultaneously transmitted,
It is necessary to equip the same number of line switching devices 14 as the number of lines, and the equipment cost of the line switching device 14 becomes extremely high. At present, design and miniaturization of the device are regarded as important. Therefore, there is a demand that it is desirable to avoid stacking multiple line switching devices as much as possible.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problem that the line switching device has a long switching waiting time and the problem of not wanting to place a line switching device at the center (calling side). It is an object of the present invention to provide a terminal switching system of a line switching apparatus which eliminates the need for setting a pause time until a signal is transmitted and eliminates the work of measuring a connection delay time.

[0010]

The terminal switching system of the line switching apparatus according to the present invention is a system in which one center and a plurality of stores transmit information via a telephone network. A control unit and a plurality of modems corresponding to the number of the stores; each of the plurality of stores includes a plurality of different types of terminals for receiving different types of information such as telephones, faxes, and data; A line switching device for branching connection to terminals corresponding to telephone numbers, connecting to one subscriber line from the telephone network, and switching connection to a terminal corresponding to the type of information from the center; Arbitrarily transmits different information such as telephone, fax, and data to the store, and the line switching device of the called store is configured to switch and connect to the corresponding terminal. In the terminal switching method of the line switching device, the line switching device of the called side store sends out a dial tone to the center when detecting an incoming call from the center, and the modem on the center side receives the dial tone every time the dial tone is detected. Sending a switching signal for sequentially switching until the terminal is connected to a corresponding terminal of a heterogeneous terminal in the store, and the line switching device of the called store is configured to switch and connect the terminal according to the switching signal from the center. It is a feature.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the prior art, the modem and the center control device at the center had no way of knowing that the line switching device at the partner had received a call. However, modems for telephone lines currently in widespread use include dial tone (400).
Hz). Therefore, the line switching device 22 of each store 21
Has a function of transmitting a dial tone to the calling side after receiving a call, and the modem 13 on the center 10 side (the calling side) is provided.
Is set to transmit a switching signal when a dial tone is detected. As a result, the modem 13 on the center 10 side can detect that the line switching device 22 on the terminal side has received an incoming call, so that the switching signal can be transmitted automatically. Therefore, the setting of the switching signal waiting time only needs to consider the time from when the modem 13 of the center 10 detects the dial tone until when the switching signal is transmitted.
The time varies depending on the performance of the modem 13, but is about 2 to 4 seconds, and the switching signal waiting time can be suppressed within about 5 seconds. As a result, even if an unspecified number of telephones dial a telephone connected to the line switching device of each store, the impression that the connection is poor is reduced, and the user can go on-hook without hanging up (hang up the telephone). ) Is gone.

[0012]

By implementing the present invention, the following effects can be obtained. (1) There is no need to set the pause time, and it is not necessary to measure the connection delay time. (2) Since the waiting time of the switching signal is shortened, even when a call is made from an unspecified number of telephones, the impression that the connection of the telephones is poor is reduced, and the on-hook (hang-up) can not be completed. Will not be lost. (3) There is no need to install a line switching device on the center side,
There is no relation to the number of lines on the center side, and wasteful capital investment is eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration example of the entire system to which the present invention is applied.

FIG. 2 is a connection explanatory diagram when a call is received from an unspecified number of telephones.

FIG. 3 is a configuration example diagram when a line switching device is also used on the center side.

[Explanation of symbols]

 10, 10 'center 11 input device 12 control unit 13 modem 14 line switching device 15 telephone 20 telephone network 21 store 22 line switching device 23 FAX 24 modem 25 data processing device 26 telephone

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C062 AA02 AA12 AA13 AB38 AB46 AC35 AC38 AE14 BA04 5C075 AB08 BB03 BB14 CD02 CD21 5K101 KK01 KK20 LL01 MM05 QQ04 QQ08 QQ10 RR21 TT06 UU04

Claims (1)

[Claims] 1. A system in which one center and a plurality of stores transmit information via a telephone network, wherein the center includes an input device, a control unit, and a plurality of modems corresponding to the number of the stores. Each of the plurality of stores has a plurality of heterogeneous terminals for receiving heterogeneous information such as telephone, facsimile, and data, and the plurality of heterogeneous terminals are branched and connected to terminals corresponding to telephone numbers, respectively, from the telephone network. A line switching device connected to one of the subscribed lines to switch to a terminal corresponding to the type of information from the center, and from the center to the store, telephone, fax,
In a terminal switching method of a line switching device configured to arbitrarily transmit different information such as data and to switch and connect the line switching device of the called store to the corresponding terminal, the line switching device of the called store Sends a dial tone to the center when an incoming call from the center is detected, and the modem on the center switches sequentially each time a dial tone is detected until it is connected to a corresponding terminal of a different type terminal in the called store. A terminal switching method for a line switching device, wherein a switching signal is transmitted, and the line switching device of the called side store switches and connects the terminal in accordance with a switching signal from a center.