JP3087877B2 - Line switching protection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line switch for protecting a transmission / reception device in a communication line, particularly a terminal station or a relay station of an optical transmission line, from a failure due to an error in switching operation when switching from a working line to a protection line. Regarding the protection method.

Conventionally, the switching operation from the working line to the protection line has been performed manually or by a switching command from a central processing unit. However, the former has many human errors, and the latter has a software runaway or a signal error. Surprisingly, mistakes frequently occurred due to transmission or the like, causing a failure in the transmission / reception device.

[0003]

2. Description of the Related Art The prior art will be described below with reference to the drawings. FIG. 7 is a summary diagram of an optical transmission line configuration formed by a plurality of lines including a protection line as an example. In the figure,
LR ₀ is a spare receiving line, LS ₀ is a spare transmitting line, SW ₀
Is a standby switching device, which constitutes a standby optical transmission line. LS ₁ , LS ₂ ,... Are the first, second,.
The working transmission lines LR ₁ , LR ₂ ,... Are _first , second,..., Working reception lines, SW ₁ , SW ₂ ,. Second,
... This constitutes a working optical transmission line.

Further, a transmission line shown by a solid line is a normal transmission system, a transmission line shown by a two-dot chain line is a backup transmission system at the time of failure, and BR is a branching device. The symbols OR and OS written in each switching device indicate the light receiving unit of the receiving device and the light emitting unit of the transmitting device in the terminal station or the relay station for simplicity, respectively. Therefore, two sets are provided for each switching device. Strictly speaking, the OR corresponds to the output point of the receiving device, and the other parts of the receiving device are to be connected between the receiving line and the input point of the present switching device. The other parts are not shown. Similarly, the OS corresponds to the input point of the transmission device, and the other parts of the transmission device are to be connected between the output point of the switching device and the transmission line. Is omitted.

[0005] Figure 8, when the n-th working line failure as an example, a connection of the pre-switching the device SW ₀ and the n-th switching device if properly switching is in switch command from the central processing unit FIG. In the figure, a solid line indicates a normal state, a two-dot chain line indicates an nth working transmission line failure, and a dotted line indicates an nth working transmission line.
The connection at the time of failure of the working reception line is shown.

[0006] The switching connection at the time of normal operation and at the time of failure will be described below with reference to FIGS. 7 and 8.
In the normal state, the signal from the standby receiving line LR ₀ is input to OR ₁ of the standby switching device SW ₀ , and the standby switching device S
After reaching OS ₂ of W _0, the spare transmission line LS
Sent to ₀ . The signal from the n working reception line LR _n is inputted to the OR ₁ of the n switching device SW _n, after again reaching the OS ₁ of the n switching device SW _n, the n from here
It is sent to the working transmission line LS _n.

As an example, a second working receiving line LR
Considering the case _{where 2} is hampered, since Setsu換Ru terminal working line in the transmission side that detected the state in standby line, signals of the pre-switching device SW ₀ through preliminary receive line LR ₀ OR
₁ and reaches the OS ₁ of the standby switching device SW ₀ , and then the second switching device is connected to the second switching device via the two-dot chain line and the branching device.
It is sent to OR ₂ switching device SW _2. Then, after the same has reached the OS ₁ of the second switching device SW _2, from which the second
It is sent to the working transmission line LS _2.

If the second working transmission line LS ₂ has failed, a signal is input to the OR ₁ of the second switching device SW ₂ via the second working receiving line LR ₂ , and the signal is input to the second switching device SW ₂
After reaching the OS _2, it is sent from here to the OR ₂ spare switching device SW ₀ through chain line and branch unit 2 points. Then, after reaching OS ₁ of the standby switching device SW ₀ ,
It is sent from here to the spare transmission line LS _0.

When both the second working reception line LR ₂ and the second working transmission line LS ₂ have failed, a signal is input to the OR ₁ of the protection switching device SW ₀ via the protection reception line LR ₀ , After reaching the OS ₂ of the switching device SW ₀ , it is output from here to the spare transmission line LS ₀ . That is, the protection line completely replaces the second working line.

[0010] As yet another example, if the first working receive line LR ₁ becomes impaired, and became the second working transmission line LS ₂ also disorders signals of the first working line spare receive line LR ₀ Is input to the OR ₁ of the auxiliary switching device SW ₀ via the same, and also reaches the OS ₁ of the auxiliary switching device SW ₀ ,
From here, via the two-dot chain line and the branching device, the first switching device S
Sent to OR ₂ of W ₁ . Then, after the same has reached the OS ₁ of the first switching device SW _1, it is sent from here to the first working transmission line LS _1. On the other hand, the signal of the second working line and the second switching device OR of SW ₂ via the second working receive line LR ₂
Is input to _1, after reaching the OS ₂ of the second switching device SW _2, and sent from here to the OR ₂ spare switching device SW ₀ through 2-dot chain line and the branch unit. Then, after reaching the OS ₂ of the standby switching device SW ₀ , it is transmitted to the standby transmission line LS ₀ from here.

[0011] Even if a fault occurs on two working lines as described above, if one is on the receiving line side and the other is on the transmitting line side,
Can be backed up with a backup line. However, "multiple switching" described in the section of [Problems to be Solved by the Invention]
Note that this is completely different from the case described above.

As described above, the switching operation from the working line to the protection line has been performed manually or by a switching command from the central processing unit. FIG. 9 is a configuration diagram showing a connection in the latter case according to the prior art in an optical transmission line as an example. In the figure, 1 is a central processing unit, 2 ₀ , 2 ₁ , 2 ₃ are switching command transmission paths, SW ₀ is a standby switching device, SW ₁ , SW ₂
Are first and second switching devices, respectively.

In this configuration, a plurality of central processing units 1 are provided.
In the example of the above, the operating state of each of the working reception line and the working transmission line of the two working optical transmission lines is monitored, and when any of the above, for example, one of the working transmission lines fails, control signal transmission path 2 ₂ and 2
₀ through preliminary that the fault current communication switching device SW ₂ and the switching device SW ₀ of spare communication line of the circuit only sends switch command, the fault transmission line as previously described in connection with FIGS. 7 and 8 Switch to transmission line.

[0014]

However, in the above-mentioned switching control method from the working line to the protection line by the switching command from the central control unit or manually, the human error, software runaway or signal error transmission is performed. For this reason, mistakes frequently occurred, which caused a failure of the transmission / reception device.

Of particular interest is multiple switching. here,
When multiple switching is defined, it refers to the phenomenon of frequent mistakes as described above, or the overlapping phenomenon of switching due to simultaneous failure of multiple working transmission lines that may occur with a low probability,
This is completely different from the case described in connection with simultaneous failure of two lines in the section of [Prior Art].

[0016] fall into several switching state, for example, in FIG. 7, the light receiving portion OR ₂ spare switching device SW _0, the optical signal from the OS ₂ of the first switching device SW _1, second switching device SW ₂
Optical signal from the OS ₂ of, ... etc. the light of all accumulated by high energy injected, it reaches the light receiving portion OR ₂ is broken.

Accordingly, it is an object of the present invention to eliminate the above-mentioned disadvantages of the prior art, and when transmitting a switching command to one switching device and a standby switching device, a switching inhibit command is always transmitted to another switching device. When no switching command is transmitted to any switching device, a switching prohibition command is transmitted to all switching devices, and the standby switching device light receiving unit is
An object of the present invention is to provide a line switching protection method for protecting against multiple switching errors or multiple switching based on simultaneous failure of multiple active transmission lines that may occur with a low probability.

[0018]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, 1 is a central processing unit, and 3 is a switching protection block according to the present invention. In the switching protection block 3, 4 is an instruction item latching means, 5 is device-specific treatment data converting means, 6 ₀ , 6 ₁ , 6 ₂ ,..., 6 _m are directly connected to control signal transmission paths to each switching device. Switching drive means 7 is a destination circulation means.

Now, in order to achieve the above-mentioned object, the present invention has the following configuration as shown in FIG. Each of the plurality of working communication lines, the protection communication line, and the control signal transmission path for monitoring the operation of the plurality of working communication lines, and when a failure occurs, a switching device for the failed working communication line and a switching device for the protection communication line. A central processing unit 1 for transmitting a switching command via the central processing unit 1 to switch the faulty working communication line to the standby communication line. And the switching protection block 3 is connected to the central processing unit 1.
Instruction latch means 4 for latching an instruction including a switching instruction from the CPU, and an output of the instruction latch means 4 is converted into treatment data for each switching device indicating whether each of the switching devices should execute or inhibit the switching. a device-specific treatment data converting means 5 for outputting said changeover driving means 6 ₀ directly connected to respective control signal transmission path to the switching device, 6 _1, 6
₂ ... 6 _m and an output timing pulse to the device-specific treatment data conversion means 5 to give a timing at which the switching device-specific treatment data is to be output, and at the same time, the output timing pulse to the switching drive means 60 _,. 6 _1, 6 _2, ...
In addition to 6 _m , there is provided a destination circulation means (Circulation = circulation switching drive) means 7 for repeatedly transmitting the treatment data for each switching device to the corresponding switching device, whereby any of the above-mentioned indications is provided. The working communication line instructed by notifying the switching device of only the switching device of the working communication line and the switching device of the standby communication line or not including the switching command to all the switching devices corresponding to the switching device. Of the switching device and the switching device of the standby communication line, and the switching of all other switching devices is prohibited.

[0020]

FIG. 2 is a time chart showing a temporal flow of signal contents in a block to which a corresponding number is added or its output or terminal in FIG. 1 showing a basic block of the present invention. The contents of these signals are specifically expressed, for example, in the form of pulse codes.

The operation will be described below with reference to FIGS. 1 and 2. First, the first to k-th instruction items (k instructions) applied from the central processing unit 1 to the switching protection block 3 are latched by the instruction item latching means 4. Of course, these instructions include designation of transmission / reception line numbers and a command to switch to a protection line when a line failure occurs. In FIG. 2, this is the second instruction item. Therefore, when no line failure has occurred, a switching prohibition command has been issued to all the switching devices.

The above-mentioned latched instructions are applied to the device-specific treatment data conversion means 5, where each of the switching devices should execute switching in accordance with the timing pulse "7" applied from the destination circulating means 7. The processing data is converted and output to the switching device-specific treatment data indicating whether or not the switching should be prohibited.

The timing pulse "7" is represented by T ₀ , T
₁ , T ₂ ,... Are output, and when they reach T _m , they return to T ₀ , and this is repeated with a period τ ₂ . The latched indication is also updated at a period τ ₁ when there is a change. FIG.
Τ ₁ = τ ₂ , but τ ₁ ≠ τ ₂ may be used. Also, although the phases of τ ₁ and τ ₂ are shifted in FIG.
It may be in phase.

The transfer destination circulation means 7 from the timing pulse "7" to be added is switching driving means 6 _0, 6
_1, 6 ₂ are also applied to respective ..., thus switching equipment-specific treatment data is divided into a control signal transmission path different to each switching device, respectively switching device SW _0, SW _2, SW _3,
..., and execution or prohibition of switching according to the instruction is performed. In FIG. 2, both the timing pulse “7” and the processing data “5” for each switching device are shown in series, but in the destination circulating means 7 and the treatment data converting means 5 for each device, for example, the period τ ₂ What is converted in parallel every time may be used.

The most important thing is that when the faulty line is present, not only the switching execution command is transmitted to the switching unit and the standby switching unit but also to all the other switching units. Means that the switching prohibition command is transmitted as before, so that an accident such as multiple switching due to a switching error does not occur.

[0026]

FIG. 3 is a block diagram showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes a CPU (Central Processin).
g Unit), a block 13 surrounded by a broken line is a switching protection unit. 13δ in the switching protection unit 13 is BUFF (Buff
er = buffer), 14 ₁ to 14 ₆ REG (Regist
er = register), 15 is a data converter, 15δ ₁ to 15δ ₃ are S / P converters (Serial-Parallel Converter)
= Serial-parallel converter) 16 is a driver surrounded by a two-dot chain line, and 17 is a counter.

In the driver 16, 61 ₁ to 61 ₄ are REGs, 62 ₁ to 62 ₄ are RS232C interfaces, and 18 ₁ , 18 ₂ , 18 ₃ ,... Are control signal transmission paths to the respective switching devices. Output terminal directly connected.

Further, REG 14 ₁ to 14 ₆ breakdown of each switching pattern REG, line designation REG,
The control direction REG, the target device REG, the device configuration REG, and the timing REG.

The relationship with FIG. 1 showing the basic blocks of the present invention is as follows. That is, the CPU 1 in FIG.
Corresponds to the central processing unit 1 in FIG. The switch protection unit 13 in FIG. 3 corresponds to the switch protection block 3 in FIG.
4 _{1-14 6} corresponds to instructions latch means 4 in switching the protective blocks 3, the data converter 15 and S / P converter 15Deruta ₁ to have 15Deruta ₃ device-specific treatment data conversion unit 5, driver 16 is switched The driving means 6 and the counter 17 correspond to the destination circulating means 7, respectively.

[0030] As is apparent from REG 14 ₁ to 14 ₆ breakdown described above, through the BUFF13δ from CPU 1, the switching pattern, line designation, the control direction,
Target device, device configuration, and timing, six instructions of (instructions) are latched to the corresponding REG of the 14 ₁ to 14 _6.

The meanings of these indications and examples of pulse codes will be described below. That is, the switching pattern indicates whether a switching command (instruction to execute switching) or a switchback command (instruction to inhibit switching) is used. Two bits are used as an example of the pulse code, and the former is "01". In the latter case, it is set to "11" or the like. Here, the term "switch back" is a term used by those skilled in the art, and means that a switch that has been switched by mistake or a switch that has been switched is returned to a normal state, rather than simply prohibiting the switch.

Next, the line designation indicates which line is concerned. The pulse code uses 5 bits as an example of the pulse code, and is "00001" for the protection line, "00010" for the first working line, "000" for the second working line
11 "etc.

The control direction indicates which one of the transmission and reception lines is related to the transmission direction.
Bits are used and are set to "0" on the transmission line side and "1" on the reception line side.

The target device means that the target device is an ADM
(Add Drop Multiplexer = Adaptive Multiplexer) or LTE (Line Terminating Equipment =
1) is used as an example of a pulse code, and “0” is used in the former case.
In the latter case, "1" is set.

The device configuration relates to the status occupied by the device in the line configuration. One bit is used as an example of a pulse code. When a DI (Drop Insert = drop and drop) station is “0”, END (End = end) ) In the case of a station, it is "1".

The term "timing" refers to a timing instruction to be used as a reference in the present line switching protection system, and corresponds to a clock. Now, the next stage of the data converter 15 is the REG 14
₁ to reads the latched above instructions to 14 _6, each of the switching devices of each line should be performed switching, and outputs the converted serial data indicating whether to prohibit specifically. For the conversion and output, a circulation timing pulse from the counter 17 is required.

The counter 17 has a timing REG at the preceding stage.
14 In response to the clock pulse from the _6, a binary number this "0000", "0001", "0010", "00
.. Are sequentially counted, and a timing pulse is generated for each count, and this is simultaneously applied to the data converter 15 and the REGs 61 ₁ , 61 ₂ , 61 ₃ ,.

In the data converter 15, each timing pulse is converted into the above-described serial data consisting of, for example, 7 bits. The number of bits is not necessarily 7 bits, but when the first bit is “0”, the OS
₂ is turned on (switching is executed), when "1", OS ₂ is turned off (switching is prohibited), and when the second bit is "0", OR ₂ is selected.
"1" selects the OR ₁ when the when the third bit is "0" selects the OS _2, select OS ₁ when "1", if defined as equal, the remaining bits sporting You may leave.

FIG. 4 is a time chart showing a signal waveform at each point of the data conversion portion in the block of FIG. In the figure, C indicates the timing pulse, and D
Indicates the serial pulse of 7 bits in the data converter 15. The waveforms E, F, G,... Respectively correspond to the first bit, the second bit, and the third bit from the 7-bit serial pulse D.
Only the bit,... Is a pulse train formed by extraction,
FIG. 3 shows the positions of the corresponding points. The waveforms J, K, M,... Correspond to the pulse trains E, F, G,
.. Are represented by S / P converters 15δ ₁ , 15δ ₂ , 15
are applied to δ ₃ ,..., and are subjected to serial-parallel conversion. The waveforms obtained at the respective output points are shown in FIG.

The signals J, K,
M, ...... is a switching device by treatment data, become a same row of the waveform shown in the rightmost, respectively in the driver _{16 REG61 1, 61 2, 61} 3, ...... and interfaces 62 _1, 62 ₂ , 62 ₃ ,... And output terminals 18 ₁ , 18
_2, 18 _3, respectively via a ...... spare switching device, the first
Are transmitted to the switching device, the second switching device,....

Here, the REGs 61 ₁ ,
61 ₂ , 61 ₃ ,...
, A timing pulse is added one by one each time counting is performed. By associating the time sequence 0, 1, 2, 3,... Of each timing pulse with a decimal number with the line number to which each switching device belongs, The processing data for each switching device can be correctly distributed to the control signal transmission path to the switching device of the line of the corresponding number.

When the total number of switching devices to be switched and controlled is 11, including the standby switching device, when the counter 17 has counted up to "1010" (decimal number 10),
Return to "0000" again, and set to repeat this circulation.

Now, the treatment data J for each switching device in FIG.
Returning to K, M,..., The data transmitted to the standby switching device is a switching execution instruction because all of the first bit, the second bit, and the third bit are “0”, In the data transmitted to the switching device, only the second bit is "1" and both the first and third bits are "0".
Become change-executing instruction for R _2, data transmitted to the second switching device to the first bit, second bit, none of the third bit is the switching inhibition command because it is "1". This has already been described in connection with the 7-bit serial pulse.

In the prior art, the control command from the central control device was directly transmitted to the switching device.
And stores check with BUFF13δ and REG 14 ₁ to 14 ₆ Once a instructions latch means 4 this in the present embodiment, then the stored items, of either specifically prohibited for either switching separately change-executing each switching device Since the signal is converted into a signal that is instructed in a centralized manner, not only the load on the central control device is reduced, but also the effect of reducing the probability of occurrence of an operation error is greatly reduced.

The functionality of the present invention can be implemented in a way that is closer to a complete software system. FIG.
FIG. 4 is a block diagram showing an example of realizing the present invention in a method close to a complete software system, that is, a second embodiment of the present invention. In the figure, 1 is a CPU, 24 is a latch,
25 is a pattern ROM, 25 is a shift register, 26 is a latch, and 27 is a counter.

The relationship with FIG. 1 showing the basic blocks of the present invention is as follows. That is, the CPU 1 in FIG.
Corresponds to the central processing unit 1 in FIG. Latch 2
4 corresponds to the instruction item latch means 4 and the pattern ROM 2
5 and the shift register 25δ correspond to the device-specific treatment data converting means 5, the latch 26 corresponds to the switching drive means 6, and the counter 27 corresponds to the transmission destination circulating means 7.

FIG. 6 shows an example in which the device configuration is END.
When the target device is LTE, when switching the first working transmission line LS ₁ to the protection transmission line LS ₀ , an instruction from the CPU 1, an address input to the pattern ROM 25,
6 is a table showing a correspondence relationship with data output from a pattern ROM 25.

The table is divided into a left table and a right table with a small break. The data column T in the right table corresponds to the address column R in the left table. The P column in the left table is an instruction from the CPU 1 described in detail including the pulse code examples in relation to the first embodiment, and the Q column sets the address in the R column from the least significant bit, that is, Unit codes are grouped every four bits from the rightmost bit in the left table, and each code is represented by a hexadecimal number. That is, A in the Q column corresponds to 10 in hexadecimal. Incidentally, in hexadecimal numbers, since numbers 10 to 16 are represented by one digit, they are indicated by alphabets A to F, respectively. The S column in the right table shows the order of each bit of the data in the T column, and the data represented in decimal notation. How to display switching execution or switching inhibition by using each bit of these data is also described in detail in relation to the first embodiment.

The data in the column T in the right table of FIG. 4, that is, the serial data, which is the output of the pattern ROM 25, is applied to the shift register 25δ at the next stage, where it is converted to serial data by the switching device to be converted into treatment data for each switching device. Is done. The switching device-specific treatment data output from the shift register 25δ is once applied to the latch 26, and then the switching device-specific treatment data is correctly distributed to the control signal transmission path to the switching device of the line of the corresponding number. .

As described above, according to the second embodiment, the CPU
In addition to using a pattern ROM and a small amount of hardware, the first embodiment can be more economically substituted mainly by software, and the line switching protection system is extremely resistant to runaway of software by introducing a pattern ROM. Can be realized.

[0051]

As described above, according to the present invention, the load on the central control unit can be reduced by introducing the instruction item latching means and the device-specific treatment data converting means.
Line switching that protects the standby switching device light receiving unit from multiple switching errors or multiple switching based on simultaneous failure of multiple active transmission lines that may occur with a low probability because the operation error occurrence probability is reduced. A protection scheme can be realized.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a time chart showing signal contents at various points in the block of FIG. 1;

FIG. 3 is a block diagram of a first embodiment of the present invention.

FIG. 4 is a waveform diagram of each point of a data conversion part in FIG. 3;

FIG. 5 is a block diagram of a second embodiment of the present invention.

FIG. 6 is an input / output correspondence table of a pattern ROM.

FIG. 7 is a summary diagram of an optical transmission line configuration.

FIG. 8 is a connection diagram of a switching device.

FIG. 9 is a configuration diagram of a conventional line switching control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central processing unit 3 Switching protection block 4 Instruction latch means 5 Device-specific treatment data conversion means 6 Switching drive means 7 Transmission circulation means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/74 G08B 29/16

Claims (1)

(57) [Claims] 1. A plurality of working communication lines, a protection communication line, and a device for monitoring the operation of the plurality of working communication lines and, when a failure occurs, a switching device for the failed working communication line and a switching device for the protection communication line. A central processing unit (1) for sending a switching command via each control signal transmission path to switch a faulty working communication line to a standby communication line. A switching protection block (3) is connected between the switching protection block (3) and a control signal transmission path to each switching device, and the switching protection block (3) latches an instruction item including a switching command from the central processing unit (1). Instruction item latch means (4); and device-specific treatment data for converting and outputting the output of the instruction item latch means (4) into switching device-specific treatment data indicating whether each of the switching devices should execute or inhibit switching. And switch means (5), said control signal switching drive means connected directly to the respective transfer path _{(6 0, 6 1, 6} 2, ...... 6 m) and the device-specific treatment of the output timing pulses to each switching device in addition to the data conversion means (5) giving the output timing of the switching device by treatment data, simultaneously adding the output timing pulse to the switching drive means _{(6 0, 6 1, 6} 2, ...... 6 m) A destination circulating means (7) for repeating the transmission of the switching device-specific treatment data to the corresponding switching device in sequence. By transmitting to all the switching devices corresponding to the switching device whether or not the switching command of only the switching device of the communication line is included, the switching device and the spare of the designated working communication line are transmitted. A line switching protection system characterized in that only the switching device of the communication line is switched and switching of all other switching devices is prohibited.