JPS60190044A - Automatic line switching system - Google Patents

Abstract

PURPOSE:To automatically switch and switch back an opposite station without branching a signal to be transmitted and transmitting in parallel at the transmission side by providing a code rule violation generating circuit to generate intermittently violation of the code rule so that the error rate of the code rule becomes a prescribed value or over at the transmission side of an active line. CONSTITUTION:A normal binary signal to be transmitted inputted to a signal input terminal 1 is fed to a switching circuit 2 at the own station transmission side, no line switching condition is generated at the normal state and the transmission side switching circuit 2 transmits the normal binary signal to be transmitted to an active line transmission section 5. When the line switching condition is produced in the own station, a line switching control signal is fed to a line switching control signal input terminal 3, the transmission side switching circuit 2 is switched to a spare line side and also the code rule violation generating circuit 6 is controlled, the violation of code rule is generated intermittently so that the error rate of the code rule is a prescribed value or over at the transmission side of the active line. The line switching condition of the own station is disappeared due to restoration of a fault or the like and the line restores to the normal state, the own station transmission side switching circuit 2 and an opposite station reception side switching circuit 11 are switched back automatically to the active line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a current technology (+iii) suitable for digital communication.
ty) Regarding automatic line switching system. In particular, using C and M engineering codes as transmission line codes, the working time +? This relates to an automatic line switching system having one line (1ii!) for fdE71.

[Description of prior art]

As for this type of automatic switching system, there are two known methods described below. In other words, in the first method, the signal to be transmitted is branched on the transmitting side, sent to the protection line and the working line in parallel, and when all line switching conditions are detected at A4Y411, the signal is switched to the pre-(iii) line. This is an automatic switching method that performs

In the second method set, the transmitting side transmits the 4g signal to the working line σ], and when the transmitting side detects the switching condition, the transmitter
The B side switches to the protection line, and the working line 4? When the number disappeared, the line was switched to the pre-G11 line.

In the first automatic [L+1 line switching method, the feed (g 1111
A branch circuit No. 3 is required for transmission and transmission.

When the branch circuit is configured with a passive circuit, the level of the signal to be transmitted decreases due to the loss of the branch circuit, and an amplifier circuit for compensation is required, leading to an increase in the circuit scale. Moreover, when a faulty part is removed for maintenance or repair of the amplifier circuit, the level of the signal to be transmitted changes. Furthermore, if the branch circuit is constituted by an active circuit so that the level of the signal to be transmitted does not change, the reliability of the branch circuit becomes -Jk<, which results in a drawback that the reliability of the line deteriorates.

Regarding the second automatic line switching method, transmission 1
, 4 will be lost, and a device will be required to retransmit the signals transmitted during the period required for switching.

[Purpose of the invention]

The present invention improves the above-mentioned drawbacks and aims to improve the (
Our aim is to provide a simple automatic line switching system that can automatically switch the opposite station without branching the Li line and without losing information about the switching period.

[Features of the invention]

The present invention is provided with one reserved line 111 for one working line, a first ring switching means for switching an input digital signal from the working line to the protection line on the transmitting side, and a first ring switching means on the receiving side 4g. a second switching means for automatically switching the working line to the predicted line J when the code rule error rate f: (■Exit 1. In the automatic line switching system of the digital Takuhaku equipped with this system, when switching the line, the sending side is sent a code that violates the code rule so that the error rate of the code rule is equal to or higher than a predetermined value on the working line. Sign rule: 1jl5 It is characterized by being equipped with a repulsion means.

[Explanation based on examples]

An embodiment of the present invention will be described with reference to drawing fc ('). The figure is a block diagram of an automatic line switching system according to an embodiment of the present invention. is connected to the transmitting side 1 switching circuit 2. times?
The line switching control input terminal 3 to which the f# switching I control signal is input is connected to the control fj11 of the transmitting side switching circuit 2 to J3 &i1
; to be done. The human car value signal is sent from the transmission side switching circuit 2 to the pre-wart 1 line transmitter 4 and the working line transmitter 5 by switching. Pre-44i 1 time + f4i! From the transmitting section 4 or the working line transmitting section 1 section 5 via the backup catalog transmission line 7 or the working line transmission line 8! The 4U number of the CMI code that
Connected to O.

The converted two (+M itT signal) and the receiving side switching circuit 11 are the
Seven times it is connected. A line switching control signal is sent from the working line receiving unit 10 to the receiving side switching circuit 1 via the 1A transmission line 135c.
Connected to 1. Receive (n (Binary signal from I1111 switch 11 is output to output terminal 12); - Insert.

Here, the ♀ characteristic of the present invention is surrounded by a single dot chain pattern (3 MIJi rule violation part).

The operation of the automatic line VJ switching system having such a configuration will be explained. In the figure, the normal binary signal input to the key input terminal l is applied to the transmitting side switching circuit 2 of the own station, and under normal conditions, the line switching condition occurs; The 0J11 switching circuit 2 sends the normal 2 (+U+ signal) to be transmitted to the working line side transmitter 5. The working line transmitter 13 5 performs OMI code conversion according to the following rule. In other words, the normal binary Ig signal "0'' versus j, (', [sign is ``0''
1J, r o O for iij + ordinary binary signal rl-1
J and r 11 are replaced by the alternating codes of J. CM
The information code converted to the work code passes through the current J11 line 1111 transmission line 8, and is returned to a binary signal by the working line receiving section ysR10 of the opposite station, and is sent to the 911 switching circuit 11 when the receiving station receives the signal.
After the appetizer, it is output to the IT output terminal 12.

When a line switching condition occurs in the local station M:1, line switching f11. is sent to the line switching control signal input terminal 3. The control E signal is applied, and at the same time, the transmission side switching circuit 2 is switched to IJJ signal 1 for the first line 1, and at the same time, the CM code rule violation generating circuit 6 is switched off.
l L, transmission of the working line (on the e side, the OMI code rule is 1.6 or I) so that the rate is 1!1 or more (i.e., the line is switched at To be able to detect the conditions) CM Kojuku Sen': Rule i'; perform the opposite intermittently.

Violation of the OMI coding rules can be done using the following rules, for example, without causing errors in the binary No. 48 (C
It is possible to violate the M engineering code rules. That is, OMI
The normal binary number 16 of the time slot that violates the coding rule is "
0”, the illusion, CM I code [+11 J is “10
”, and normally when the binary signal is “1”, the sentence “00” and “11” are sent only in that time slot? ! Forbidden i1
Just heat it.

In the receiving section of the working line of the opposite station, the error rate of the CM■ code rule is greater than the predetermined 13, so the number of times +? (When the β switching condition is detected, the receiving iT (lIQ u'l switching circuit 11 is connected to the ignition line 13f: ?'d L) J switching control (g is added and switched to the protection line 1, When the line switching condition of the own station disappears due to failure recovery, etc., and the state returns to normal, the CM code rule violation will no longer occur, and the CMI code rule will normally return to A; The circuit 2 and the receiving side switching circuit 11 of the other station are automatically switched back to the current one.

The same purpose can also be achieved by using other transmission line codes (AM code, DMI code, etc.) instead of the OMI code.

In the method of the present invention, the method shown in the figure is
This is particularly useful when the working reserve is configured to be switched in both directions simultaneously.

In other words, if similar circuits are provided in both the stop direction and the down direction, if there is a fault in the upstream working transmission line and a switching condition is detected on the upstream receiving side, the 1c
X, the downlink transmission Me (till generates a coding rule violation and switches the downlink transmission path to the preliminary 1iii transmission path, and in conjunction with this, switches the upstream transmission path to the backup transmission path. , Even if there is a transmission line failure, the self+I71
+Switching will occur.

〔Effect of the invention〕

As explained above, the present invention provides a coding rule violation generating circuit, and intermittently violates the coding rule when the error rate of the signal rule exceeds a predetermined value on the transmitting 4M side of the working line. This has the advantage of being able to automatically switch and switch back to the other station without branching the signals to be transmitted and transmitting them in parallel, and without losing information during the switching period.

[Brief explanation of the drawing]

The figure is a block diagram of an automatic line switching system according to an embodiment of the present invention. 1...Signal input terminal, 2...Transmission side switching circuit, 3.
...Line switching ftt control signal input terminal, 4...Protection line transmission HXB, 5...Working line transmission section, 6...OM
I code rule violation generation circuit, 7...protection line transmission line, 8.
... Working line transmission line, 9... Protection line receiving section, 10.
・・Working line receiving section 11 ・・Receiving unit 8 switching circuit, 12
...Signal output terminal, 13...Signal &! . Patent applicant: NEC Corporation Representative Patent attorney: Naotaka Ide

Claims (1)

[Claims] (1) One protection line for one working line
1fi, a first switching means for switching the input digital 4H signal from the working line to the protection line on the transmitting side, and a first switching means on the receiving side (iT side,
a second slip means for automatically switching the working line to the protection line when a code rule error rate of a predetermined value or higher is detected in the digital signal of the working line; In this case, the transmitting side is provided with a coding rule violation generating means (4! J
Automatic line switching system.