JPH03219758A - Method and apparatus for switching communication line - Google Patents

Abstract

PURPOSE:To prevent an increased rate of production of a data transmission error when a public line is selected by assigning the public line with better line quality is assigned to a line with much data transmission quantity of a 4-wire exclusive line set in advance. CONSTITUTION:When a line fault takes place in a private line 30, the private line 30 is switched into public lines 41, 42 and 43, 44 via an exchange network 40. Then a quality measuring section 18 of a center side MODEM 10 measures the quality of lines 41, 42 and 43, 44. When the quality of the lines 41, 42 is better than that of the lines 43, 44 as the result of measurement, a switching signal transmission section 16 is controlled to use the lines 41, 42 as outgoing lines and a line switching section 12 is controlled to select incoming lines to the lines 43,44. Moreover, when the quantity of data transmission of the incoming line is more than that of the outgoing line as the setting in a storage section 17 of a device 10, the public line with better quality is switched automatically to the incoming line with similar operation.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention comprises a center-side modem and a remote-side modem that is connected to the center-side modem through a four-wire dedicated line, The present invention relates to a communication line switching method and apparatus for switching a communication line between a center-side modem and a remote-side modem from a four-wire dedicated line to two sets of public lines.

[Conventional technology]

Conventionally, communication line switching systems include a center-side modem and a remote-side modem that is connected to the center-side modem through a 4-wire dedicated line, and when a line failure occurs, the center-side modem and remote-side modem are switched. The communication line between the equipment has been switched from a 4-wire private line to two sets of public lines.

In such a communication line switching system, the communication line is switched from a dedicated line to a public line in the event of a line failure, regardless of the amount of data transmission on the uplink and downlink.

[Problems to be Solved by the Invention] However, according to such a conventional communication line switching system, if a line with a large amount of data transmission is assigned to a public line with poor line quality, the data transmission will be interrupted. There is a problem in that the rate of error occurrence increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication line switching method and apparatus that can eliminate such drawbacks and prevent data transmission errors from increasing at a high rate when switching to a public line.

[Means to solve the problem]

In the present invention, a modem on the center side transmits data to a modem on a remote side via a 4-wire dedicated line consisting of an uplink and a downlink, and when a failure occurs on this 4-wire dedicated line. Then, in the communication line switching method for switching to two sets of public lines, the uplink and downlink of the 4-wire dedicated line with a larger amount of data transmission is set in advance, and in the event of a failure of the 4-wire dedicated line, The line quality of the two switched public lines is measured, and the public line with the better line quality determined by this measurement is used as the preset 4-wire dedicated line with the highest amount of data transmission. It is characterized by being assigned to

In addition, the present invention provides that the modem on the center side transmits data to the modem on the remote side via a 4-wire dedicated line consisting of an uplink and a downlink, and when there is a problem with this 4-wire dedicated line, In the communication line switching method of switching to two sets of public lines when a problem occurs, the modem on the center side sets in advance the line with a larger amount of data transmission among the uplink and downlink of the 4-wire dedicated line, The modem on the center side measures the line quality of the two public lines switched to when the four-wire dedicated line fails, and the modem on the center side selects the public line with the better line quality as determined by this measurement. is assigned to the preset 4-wire leased line with a larger amount of data transmission, and at the same time, information regarding this assignment is sent to the modem on the remote side, and the modem on the remote side The system is characterized in that, based on information from the modem on the center side, a public line with good quality is assigned to a line with a large amount of data transmission.

Further, in the present invention, the modulation/demodulation means of the modem on the center side transmits data with the modulation/demodulation means of the modulation/demodulation on the remote side via a four-wire dedicated line consisting of an uplink and a downlink. In a communication line switching device in which, when a failure occurs in the dedicated line, the switching means of each modem switches the dedicated 4-wire line to two sets of public lines, wherein the modem on the center side switches the dedicated 4-wire line to the 4-wire dedicated line. A storage means for presetting whichever of the uplink and downlink lines has a larger amount of data transmission, and measures the line quality of the two sets of public lines when a failure occurs in the 4-wire dedicated line. a measuring means; and a control means for controlling switching of the switching means of the modem on the center side based on the measurement results of the measuring means, and allocating a public line with good line quality to the line set in the storage means. and transmitting means for generating a switching signal based on the assignment of the control means and transmitting it to the remote modem via a public line, and the remote modem is configured to transmit a switching signal to the modem at the center side. receiving means for receiving a switching signal from the transmitting means; and controlling switching of the switching means of the remote modulation/demodulation device based on the switching signal received by the receiving means, and controlling the switching of the switching means of the remote modulation/demodulation device to connect a high-quality public line with a large amount of data transmission. It is characterized by having a control means for allocating to lines.

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

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

Note that this embodiment is applied to a communication system.

The communication line switching device shown in FIG. Public lines 41 to 44 are provided between the modem devices 10 and 20 via a network 40.

The center side modem 10 includes a quality measurement unit 18 that measures the line quality of the public side vAs 41 and 43, and a network control unit 14 that makes a call to the remote side modem 20 via the public line.
and 15, a storage unit 17 that stores the uplink or downlink, whichever has a larger amount of data transmission, a line switching unit 12 that switches the line from a private line to a public line, and a line switching signal to the remote modem 20. a control section that controls the network control sections 14 and 15, the line switching section 12, and the switching signal transmission section 16 based on the contents of the storage section I7 and the signal from the quality measurement section 18; 13, and a modulation/demodulation section 11 connected to public lines 41 and 43 via a dedicated line 30 and network control sections 14 and 15.

The remote side modem 20 is the center side modem 10.
network control units 24 and 25 that receive calls from other parties; and a line switching unit 22 that switches the line from a private line to a public line.
, a switching signal receiving section 26 that receives a line switching signal from the center side modem 10, and a network control section 24 and 2.
5 and a control section 23 that controls the line switching section 22 based on the signal from the switching signal receiving section 26; and a dedicated line 30.
and public lines 42 and 4 via network control units 24 and 25.
4, and a modulation/demodulation section 21 connected to

In addition, the public lines 41 and 43 are connected to the center side modem equipment l.
lines to O, public lines 42 and 44 are lines to remote modem 20, and switched network 40 is public lines 41 and 42.
and connects public lines 43 and 44.

Next, the operation of this embodiment will be explained.

Normally, the line switching section 12 of the center-side modem 10 connects the modem 11 to the downlink and uplink of the four-wire dedicated line 30 under the control of the control section 13.

Similarly, the line switching unit 22 of the remote modem 20 switches the modem 21 under the control of the control unit 23.
It connects to the downlink and uplink of the 4-wire dedicated line 30.

Thereby, the modem section 11 of the center side modem device 10 transmits data with the modem section 21 of the remote side modem device 20 via the dedicated line 30. In this way, the line switching unit 12 of the center-side modem 10 and the line switching unit 22 of the remote-side modem 20 are connected to the dedicated line 3.
In the connected state switched to 0. In this connection state, it is assumed that the storage unit 17 of the center-side modulation/demodulation device 10 stores that the amount of data transmission on the downlink is greater than the amount of data transmission on the uplink.

In such a situation, if a line failure occurs in the leased line 30 and the lines are switched from the leased line 30 to the public lines 41 and 42 and 43 and 44 via the switched network 40,
The control unit 13 of the center modem 10 controls the network control unit 14 and the network control unit 15, and calls the public lines 42 and 44 of the remote modem 20, respectively, via the switched network 40. Network control units 24 and 2 of the remote modem 20
5 receives a call, public lines 41 and 42 and public lines 43 and 44 are connected.

After that, the quality measurement unit 18 of the center side modem 10
Line quality of public lines 41 and 42, and 43 and 44 is measured.

As a result of this measurement, if the line quality of the public lines 41 and 42 is better than the line quality of the public lines 43 and 44, the control unit 13 of the center side modem 10 refers to the contents of the storage unit 17, and the switching signal transmitting unit 16 , and causes the remote modem 20 to transmit a signal indicating that the public lines 41 and 42 are to be used as downlinks.

Furthermore, the control section 13 of the center side modem 10 controls the line switching section 12 to switch the uplink to the network control section 5 side and switch the downlink to the network control section 14 side. The remote modem 20 switches the signal transmitted from the center modem 10 and indicates that the public lines 41 and 42 are to be used as downlinks to the signal receiving unit 2.
6 detects. The switching signal receiving section 26 that detected this
The control unit 23 controls the line switching unit 22 using the signal from the line switching unit 22 . The line switching unit 22 connects the uplink to the network control unit 25.
and the downlink is switched to the network control unit 24 side.

In this switching, even if the line quality of public lines 42 and 43 is better than that of public lines 41 and 42, use the same method to use public lines 42 and 43 as downlinks and switch public lines 41 and 42 as uplinks. Switch the line to use. Additionally, if it is set in the storage unit 17 of the center modem 10 that the amount of data transmitted is larger on the uplink than on the downlink, the public line with better line quality will be automatically used as the uplink using the same operation. Switch to line.

In this way, the center-side modem and the remote-side modem are connected to the center-side modem through a 4-wire dedicated line, and in the event of a line failure, the center-side modem and the remote-side modem can be connected to each other. In this example, the communication line is switched from a 4-wire private line to two sets of public lines.The uplink and downlink, whichever has the highest amount of data transmission, is set in advance, and in the event of a line failure, the two connected lines public line with better line quality,
Automatically allocates to the line with the highest amount of data transmission.

〔Effect of the invention〕

As explained above, according to the present invention, the uplink and downlink of the 4-wire dedicated line, whichever has a larger amount of data transmission, is set in advance, and in the event of a line failure, two sets of lines are selected from the 4-wire dedicated line. When switching to a public line, the one with better quality of the two connected public lines is automatically assigned to the line with the highest data transmission volume.
It is possible to prevent a high rate of data transmission errors from being assigned to a public line with poor line quality due to a line with a large amount of data transmission being allocated, and it is possible to always perform communication with fewer data transmission errors.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. 10.20・・・ 11.21・・・ 1222・・・ 13, 23・・・ 14.15,24° 16・・・・・・ 17・・・・・・ 18・・・・・・ 26・・・・・・ 30・・・・・・ 40・・・・・・ 41～44・・・ modem Modulation/demodulation section Line switching section control part 25...Network control unit Switching signal transmitter storage section Quality measurement department Switched signal receiving section 4-wire dedicated line public network public line

Claims (3)

[Claims] (1) The modem on the center side transmits data to the modem on the remote side via a 4-wire dedicated line consisting of an uplink and a downlink, and if a failure occurs on this 4-wire dedicated line, In the communication line switching method for switching to two sets of public lines, the uplink and downlink of the 4-wire dedicated line with a higher amount of data transmission is set in advance, and switching is performed in the event of a failure of the 4-wire dedicated line. The line quality of the two public lines was measured, and the public line with the better line quality determined by this measurement was replaced with the preset 4-wire dedicated line with the highest amount of data transmission. A communication line switching method characterized by assigning. (2) The modem on the center side transmits data to the modem on the remote side via a 4-wire dedicated line consisting of an uplink and a downlink, and if a failure occurs in this 4-wire dedicated line, In the communication line switching method for switching between two sets of public lines, the modem on the center side sets in advance the line with a larger amount of data transmission among the uplink and downlink of the 4-wire dedicated line, and the modem on the center side The modem at the center measures the line quality of the two public lines that were switched in the event of a failure of the four-wire dedicated line, and the modem at the center selects the public line with the better line quality determined by this measurement. At the same time, information regarding this assignment is sent to the modem on the remote side, and the modem on the remote side instructs the modem on the center side. A communication line switching method characterized in that a public line with good quality is assigned to a line with a large amount of data transmission based on information from a modem and a modem. (3) The modem means of the modem on the center side transmits data to the modem means of the modem on the remote side via a 4-wire dedicated line consisting of an uplink and a downlink, and this 4-wire dedicated line In a communication line switching device in which switching means of each modem switches a 4-wire private line to two sets of public lines when a fault occurs on a line, the modem on the center side switches the upstream of the 4-wire private line. A storage means for presetting whichever of the line and the downlink has a larger amount of data transmission; and a measuring means for measuring the line quality of the two sets of public lines when a failure occurs in the four-wire dedicated line. , a control means for controlling switching of the switching means of the modem on the center side based on the measurement result of the measuring means, and allocating a public line with good line quality to the line set in the storage means; a transmitting means that generates a switching signal based on the allocation of the means and sends it to the remote modem via a public line, and the remote modem transmits a switching signal from the transmitting means of the center modem. a receiving means for receiving a switching signal of the receiving means; and controlling switching of the switching means of the remote modem device based on the switching signal received by the receiving means, and allocating a public line with good quality to a line with a large amount of data transmission. 1. A communication line switching device comprising a control means.