JP2001339369A - Instantaneous interruption switching circuit and method - Google Patents

Abstract

(57) [Summary] [Problem] To fully utilize the non-interruptible switching function of an opposing transmission device and expand the phase difference guarantee range between the two systems in which non-instantaneous switching is possible. A non-instantaneous interruption switching circuit or method that can be dealt with by changing only the non-instantaneous interruption switching circuit of one of the transmission devices without changing the instantaneous interruption switching circuit of the transmission device. SOLUTION: When a phase difference A between both systems is equal to or less than a phase difference (threshold value) B at which the maximum phase can be adjusted, the opposite transmission device 119 is used.
In (2), the phase of the data of both systems is adjusted (through control). When the phase difference A between the two systems is larger than the threshold value B, the transmission apparatus 101 performs the maximum phase adjustment that can be performed on the signals of both the systems. In this case, the phase adjustment units 109 and 110 of the transmission device 101 and the phase adjustment units 128 and 129 of the transmission device 119 perform the phase adjustment of X + B = (AB) + B = A. , The instantaneous interruption switching can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instantaneous interruption switching circuit and method, and more particularly to an instantaneous interruption switching circuit and method in a transmission device having a redundant configuration.

[0002]

2. Description of the Related Art Conventionally, when two-way transmission and reception are performed in transmission apparatuses opposed to each other, a transmission path between a 0-system (for example, an operating system) signal and a 1-system (for example, a standby system) signal. Was switched as follows. First, when a failure of the transmission line of the system 0 is detected, a transmission line switching request is transmitted from one transmission device to the other transmission device facing the transmission line.
The other transmission device that has received the switching request operates the switching unit to switch to the first transmission line, and then sends a switching response to one of the opposing transmission devices. One of the transmission devices that has received the switching response operates the switching unit to switch to the first transmission line. Thus, bidirectional switching has been completed.

[0003] On the other hand, in the case of switching due to trouble transfer, etc., it is necessary to execute instantaneous interruption switching. In general, however, in the transmission device on the transmitting side, the phase of the 0-system signal and the 1-system signal is one. Even if they do, the transmission device on the receiving side may have a phase difference due to various causes. Therefore, it is necessary to perform phase matching in front of the switching unit of the transmission device on the receiving side. For this reason, a phase difference between the operating system and the standby system is detected, and instantaneous interruption switching is performed using the phase adjustment circuit. Was. In order to detect the phase difference, for example, a transmission-side transmission device generates a phase difference detection multi-frame (MF) composed of overhead bits or bytes, inserts the multi-frame into a transmission signal, and the reception-side transmission device transmits a multiframe (MF). Non-instantaneous interruption switching has been performed by detecting the MF phase difference between the system signal and the system 1 signal.

FIG. 6 is a block diagram of a conventional non-stop switching circuit between transmission apparatuses. In FIG.
Reference numerals 1 and 119 denote transmission devices 102, 10
Reference numerals 3, 104, and 105 denote interface (IF) units for interfacing the transmission apparatus 101, 120, 12, and 12.
1, 122 and 123 are interface (IF) units for interfacing with the transmission device 119; 115 is, for example, a 0-system transmission path from the transmission device 101 to the transmission device 119;
Reference numeral 116 denotes, for example, a transmission path of the first system from the transmission apparatus 101 to the transmission apparatus 119, and 117 denotes a transmission path from the transmission apparatus 119 to the transmission apparatus 1
For example, a transmission line of system 0 to 01, 118 is a transmission device 119
A transmission path from the transmission apparatus 101 to the transmission apparatus 101, for example, an MF generation unit 107 for non-interruptible switching of the transmission apparatus 101 that generates an MF used for detecting a phase difference between the 0 system and the 1 system, Reference numeral 125 denotes an MF generation unit for instantaneous interruption switching of the transmission apparatus 119, and reference numeral 106 denotes an MF insertion for instantaneous interruption switching of the transmission apparatus 101 for inserting the MF generated by the MF generation unit 107 for instantaneous interruption switching into a 0-system signal. , 108 is an MF generator 1 for instantaneous interruption switching
The MF insertion unit for instantaneous interruption switching of the transmission apparatus 101 that inserts the MF generated in 07 into the 1-system signal, and the MF insertion unit 124 inserts the MF generated by the MF generation unit 125 for instantaneous interruption switching into the 0-system signal. MF insertion unit for instantaneous interruption switching of transmission
Reference numeral 6 denotes an instantaneous interruption switching M of the transmission device 119 for inserting the MF generated by the instantaneous interruption switching MF generation unit 125 into the signal of the first system.
The F insertion unit 109 adjusts the phase of the 0-system signal in which the MF for instantaneous interruption switching is inserted by the MF insertion unit for instantaneous interruption switching 106 according to the phase difference output from the MF phase difference detection unit 111 (described later). The phase adjustment unit 110 performs the phase change of the signal of the first system in which the MF for instantaneous interruption switching is inserted by the MF insertion unit 108 for instantaneous interruption switching based on the phase difference output from the MF phase difference detection unit 111 (described later). A phase adjustment unit for adjusting the frequency;
MF phase difference detection unit for inputting the 0-system signal output from the MPU and the 1-system signal output from the IF unit 105 and detecting the phase difference of the MF inserted in both signals.
A phase adjustment unit that adjusts the phase of the 0-system signal output from the IF unit 4 based on the phase difference detected by the MF phase difference detection unit 111, and 113 converts the phase of the 1-system signal output from the IF unit 105 to the MF phase difference A phase adjustment unit 114 that adjusts the phase based on the phase difference detected by the detection unit 111;
0 signal whose phase has been adjusted by
The switching units 114 and 127 that perform switching between the first-system signal whose phase has been adjusted by the first unit and the second-system signal output from the IF unit 121 and the first-system signal output from the IF unit 121, respectively. MF for detecting phase difference of MF inserted in signal
The phase difference detection unit 128 receives 0 output from the IF unit 120.
The phase adjustment unit 129 that adjusts the phase of the system signal based on the phase difference detected by the MF phase difference detection unit 127, and the phase of the system signal output from the IF unit 121 is detected by the MF phase difference detection unit 127. And a switching unit 130 that switches between the 0-system signal whose phase has been adjusted by the phase adjusting unit 128 and the 1-system signal whose phase has been adjusted by the phase adjusting unit 129. .

Next, the operation will be described. As shown in FIG. 6, the flow of a signal from the transmission device 119 to the transmission device 101 will be described first. In the transmission device 119 opposed to the transmission device 101, an MF generator for instantaneous interruption switching is added to an empty bit of a signal such as a 0-system or 1-system signal (hereinafter simply referred to as a “signal”) branched at a node N1. The MF generated at 125 is inserted at the MF insertion unit 124 or 126, respectively. The signals into which the MFs are inserted are transmitted through the transmission IF sections 122 or 123 and the transmission signals 117 and 118, respectively, so that the same signals are transmitted in the same phase.

[0006] The signal transmitted to the receiving IF unit 104 or 105 of the transmission apparatus 101 through the transmission path 117 or 118, respectively, depends on the difference in the transmission path length between the transmission paths 117 and 118. Has a phase difference between the signal input to the IF unit 104 and the data input to the receiving IF unit 105. The MF phase difference detection unit 111
The MF is extracted from each signal passed through the reception IF unit 104 or 105, and the phase difference between the 0 system and the 1 system is detected based on the information of the extracted MF. The phase of the data of the two systems is adjusted by the phase adjustment unit 112 or 113 so that the data of the two systems have the same phase. As a result, the phases of both systems can be adjusted before the switching unit 114, and the switching unit 114 can realize instantaneous interruption switching.

Next, the flow of a signal from the transmission apparatus 101 to the transmission apparatus 119 will be described. The MF generated by the MF generator 107 for instantaneous interruption switching is added to the vacant bit of the 0-system or 1-system signal branched at the node N2.
Or at 108 respectively. Next, the phase adjustment unit 10
9 or 110 adjusts the phases of the signals of both systems so that the phase difference detected by the MF phase difference detection unit 111 is added. The phase-adjusted signals are transmitted to the transmission IF unit 102.
Alternatively, the data is sent to the transmission device 119 via the transmission path 115 or 116 via the communication line 103.

[0008] The signal transmitted to the transmission apparatus 119 through the transmission path 115 or 116 is received by the IF unit 1 for reception.
20 or 121 are input with almost the same phase. The MF phase difference detection unit 127 receives the IF unit 120 or 12 for reception.
MF is extracted from each signal passing through
By detecting the phase difference between the two systems based on the information of F, the phases of the data of both the systems are slightly adjusted by the phase adjustment unit 128 or 129 to make the data of both the systems the same phase. As a result,
The phases of both systems can be adjusted before the switching unit 130, and the switching unit 130 can realize instantaneous interruption switching.

[0009]

As described above, in the conventional instantaneous interruption switching circuit or method, the MF phase difference detection unit 111 applies signals of both systems transmitted from the transmission apparatus 101 to the opposite transmission apparatus 119. By adding the detected phase difference, the receiving IF unit 12
0 and the IF unit 121 are arranged so that the phases of the signals of both systems are aligned. For this reason, the phase adjustment function (non-instantaneous interruption switching function) of the transmission device 119 that originally faces does not work, and
There was a problem that it could not be used.

[0010] Further, in the future, if the distance between the transmission devices is increased by accommodating further remote subscribers who use the transmission device, the range of guaranteeing the phase difference between the two systems that can be switched without interruption is accompanied by this. Need to expand. At this time, in the conventional hitless switching circuit or method, the change of the hitless switching circuit in both opposing transmission devices involves, for example, an increase in the memory capacity, or the transmission device 11 facing the transmission device 101.
A phase adjustment circuit that can adjust the phase difference of the signal transmitted from the transmission apparatus 101 to the transmission apparatus 119 to a phase difference that allows instantaneous interruption switching without using the instantaneous interruption switching function of No. 9 is required. However, also in the latter case, there is a problem that the instantaneous interruption switching function of the transmission device 119 cannot be utilized similarly to the above-described case.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problem, and to make full use of the non-instantaneous switching function of an opposing transmission apparatus, and to enable both systems to be able to perform instantaneous uninterruptible switching. When expanding the phase difference guarantee range between the two transmission devices, it is possible to cope by changing only the non-stop switching circuit of one transmission device without changing the non-stop switching circuit of both transmission devices. That is, it is an object of the present invention to provide an instantaneous interruption switching circuit or a method capable of expanding the guaranteed range of the phase difference between the two systems capable of instantaneous interruption switching even when the opposing transmission apparatus is an existing transmission apparatus.

[0012]

SUMMARY OF THE INVENTION An instantaneous interruption switching circuit of the present invention performs instantaneous interruption switching between a system 0 and a system 1 between a transmission apparatus and a transmission apparatus opposed to the transmission apparatus. A zero-interruption switching circuit on the transmission apparatus side, wherein the 0-system pattern extraction unit extracts a transmission unit having a predetermined bit pattern from the 0-system signal received from the opposite transmission apparatus; A first-system pattern extraction unit for extracting a transmission unit having a predetermined bit pattern from the received first-system signal, and a predetermined phase difference indicating a non-instantaneous interruption switchable range in the opposed transmission device are set. A phase difference setting unit,
Detecting a phase difference between the 0-system signal and the 1-system signal based on the transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit; If it is determined that the detected phase difference exceeds the predetermined phase difference set by the phase difference setting unit, the detected phase difference is adjusted by the phase adjustment amount of the signal transmitted to the opposite transmission device. And a phase difference detection unit that outputs the result as

Here, in the hitless switching circuit of the present invention, the transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit are each used for instantaneous interruption switching. A phase difference between the multi-frame extracted by the 0-system pattern extraction unit and the multi-frame extracted by the 1-system pattern extraction unit. It can be.

Here, in the instantaneous interruption switching circuit of the present invention, the transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit are each transmitted from the opposing transmission device. The phase difference detected by the phase difference detection unit is determined by the position of the cyclic redundancy check code extracted by the 0-system pattern extraction unit and the 1-system pattern extraction. And a phase difference between the position of the cyclic redundancy check code extracted by the section.

Here, in the instantaneous interruption switching circuit of the present invention, the transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit are each transmitted from the opposing transmission device. The phase difference detected by the phase difference detector is constituted by all bits of the received signal.
The phase difference between a predetermined bit position in all the bits extracted by the system pattern extraction unit and a predetermined bit position in all the bits extracted by the first system pattern extraction unit can be used. Things.

Here, the instantaneous interruption switching circuit according to the present invention is arranged such that, in place of the phase difference setting unit, a 0-system signal received from the opposed transmission device or a 1-system signal received from the opposed transmission device. A phase difference extraction unit that extracts a predetermined phase difference indicating a range in which the instantaneous interruption switch can be performed in the opposed transmission device set in the phase difference detection unit, wherein the phase difference detection unit is extracted by the phase difference extraction unit. Using a predetermined phase difference, it can be determined whether or not the phase difference between the system 0 and the system 1 exceeds the predetermined phase difference.

Here, the instantaneous interruption-free switching circuit of the present invention is a transmission circuit for adjusting a phase of a signal to be transmitted to the opposing transmission device based on the exceeding phase difference outputted from the phase difference detecting section. A 0-system phase adjustment unit, and a transmission 1-system phase adjustment unit that adjusts the phase of a signal to be transmitted to the opposed transmission device based on the exceeding phase difference output from the phase difference detection unit. A 0-system phase adjustment unit that adjusts the phase of a signal used for instantaneous interruption switching of the transmission device based on the exceeding phase difference output from the phase difference detection unit, and an output from the phase difference detection unit. A 1-system phase adjustment unit that performs phase adjustment of a signal used for instantaneous interruption switching of the transmission device based on the phase difference that has been exceeded, and the transmission 0-system phase adjustment unit; Transmission 1-system phase adjuster The 0-system phase adjustment portion and said one
The phase adjustment unit of the system can have a detachable recording unit.

The instantaneous interruption switching method according to the present invention is an instantaneous interruption switching method on the transmission apparatus side that performs instantaneous interruption switching between a system 0 and a system 1 between a transmission apparatus and an opposite transmission apparatus. Extracting a transmission unit having a predetermined bit pattern from a 0-system signal received from the opposite transmission apparatus, and extracting a transmission unit having a predetermined bit pattern from the first-system signal received from the opposite transmission apparatus; A pattern extraction step for the first system for extracting a transmission unit having: 0, 1 and 2 based on the transmission unit extracted by the pattern extraction step for the 0 system and the transmission unit extracted by the pattern extraction step for the 1 system. A phase difference detection step of detecting a phase difference between the transmission system and the phase difference detected by the phase difference detection step, the range in which the opposing transmission device can switch without instantaneous interruption. If it is determined that exceeds the to predetermined phase difference is obtained by an output step of outputting the phase difference exceeds the as the phase adjustment amount of the signal to be transmitted to the transmission device for the facing.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 shows a hitless interruption switching circuit according to Embodiment 1 of the present invention. In FIG. 1, a range surrounded by reference numeral 10 is an MF phase difference detection unit used in the hitless switching circuit according to the first embodiment, and IF units 104 and 105 and phase adjustment units 109 and 11 outside this range.
For example, 0, 112, and 113 need only have the same functions as those shown in the conventional transmission apparatus 101 shown in FIG. That is, the instantaneous interruption switching circuit according to the first embodiment is, for example, the MF phase difference detection unit 1 in the conventional transmission device 101 shown in FIG.
It can be considered that 11 is replaced with the MF phase difference detection unit 10 shown in FIG. This MF phase difference detector 1
The transmission device 119 facing the transmission device 101 replaced with 0 may be an existing transmission device.

In FIG. 1, reference numeral 12 denotes an MF extraction unit (0-system pattern extraction unit) for extracting an MF for instantaneous interruption switching (transmission unit having a predetermined bit pattern) from the IF unit 104, and 13 denotes an IF unit 105. An MF extraction unit (1st-system pattern extraction unit) that extracts the MF for instantaneous interruption switching from a transmission device, for example, sets a phase difference (threshold) B capable of adjusting the maximum phase of a transmission device opposed thereto, for example, the transmission device 119. Threshold setting section (phase difference setting section), 11 is MF extraction sections 12 and 13
Is a phase difference detection unit that detects the phase difference A between the two systems based on the MF extracted by the above and the threshold value B set by the threshold value setting unit 14. Here, the threshold value B set by the threshold value setting unit 14 is fixedly set.

Next, the operation will be described. As shown in FIG. 1, the MF extraction unit 12 or 13 is connected to an opposite transmission device, for example, the transmission device 119 to the IF unit 104 or 10.
MF for instantaneous interruption switching from signals sent through
Is extracted and sent to the phase difference detection unit 11. Threshold setting unit 1
4 sends the set threshold value B to the phase difference detection unit 11. The phase difference detector 11 detects the phase difference A between the two systems,
The phase adjusters 109 and 110 are controlled based on the results of the following conditions.

[0023]

(Equation 1)

That is, when the phase difference A between the two systems is within the range where instantaneous interruption switching is possible in the opposing transmission device 119, that is, the phase difference A (threshold) B at which the maximum phase can be adjusted is obtained. In the following case, the opposite transmission device 119 adjusts the phase of the data of both systems (Equation 1). In this case, the phase adjustment units 109 and 110 of the transmission apparatus 101 do not control the phase adjustment (through control). As a result, phase adjustment, that is, non-instantaneous interruption switching is performed in the opposite transmission device 119.

On the other hand, when the phase difference A of both systems is
In the case where it exceeds the range in which the instantaneous interruption switching is possible in 19,
That is, when the phase difference A between the two systems is larger than the phase difference (threshold) B at which the maximum phase can be adjusted, the transmission apparatus 101 performs the maximum phase adjustment that can be performed on the signals of both systems (Equation 2). In this case, the phase adjusters 109 and 110 adjust the phase difference X (= AB) where the phase difference A between the two systems exceeds the phase difference at which the maximum phase can be adjusted. That is, the transmission device 1
01 and the transmission device 11
X + B = (A−B) +
Since the phase adjustment of B = A is performed, the switching unit 130 of the transmission device 119 can perform instantaneous interruption switching.

The phase adjustment unit 112 or 113 can adjust the signals of both systems to have the same phase based on the phase difference A of both systems detected by the phase difference detection unit 11.

As described above, according to the first embodiment, when the phase difference A between the two systems is equal to or less than the phase difference (threshold) B at which the maximum phase can be adjusted, the phase difference between the data of the two systems in the opposite transmission device 119 is determined. Make adjustments. That is, the phase adjustment units 109 and 110 of the transmission apparatus 101 do not control the phase adjustment (through control), so that the phase adjustment function of the opposing transmission apparatus 119, that is, the instantaneous interruption switching function can be used.
On the other hand, when the phase difference A between the two systems is larger than the phase difference (threshold) B at which the maximum phase can be adjusted, the transmission device 101 performs the maximum adjustable phase adjustment for the signals of both the systems. In this case, the phase adjustment units 109, 110,
And X in the phase adjustment units 128 and 129 of the transmission apparatus 119.
Since the phase adjustment of + B = (AB) + B = A is performed, the switching unit 130 of the transmission device 119 can perform instantaneous interruption-free switching.

Embodiment 2 FIG. 2 shows a hitless interruption switching circuit according to Embodiment 2 of the present invention. 2 that have the same reference numerals as those in FIG. 1 have the same functions, and a description thereof will be omitted. In FIG. 2, reference numeral 22 denotes a cyclic redundancy check (CRC) extraction unit provided in place of the MF extraction unit 12 of the first embodiment shown in FIG.
23 is a CRC extraction unit provided in place of the MF extraction unit 13 of the first embodiment shown in FIG. 1, and 21 is a CRC extracted by the CRC extraction units 22 and 23 and set by the threshold value setting unit 14. A phase difference detection unit that detects a phase difference A between the two systems based on the threshold value B.

The CRC method is one of the methods for detecting an error in a block of a signal. The CRC method divides a signal as a higher-order polynomial by a predetermined generator polynomial, and modulates the remainder by a BCC (Bloc).
k Check Code) at the end of the signal block. Therefore, the MF in the first embodiment
Instead of detecting the phase difference, the CRC extraction units 22 and 23 detect the CRC attached to the end of the signal block of both systems, whereby the phase difference A of both systems can be obtained. After detecting the phase difference A between the two systems, the phase difference detection unit 21 controls the phase adjustment units 109 and 110 using the above-described equations 1 and 2 in the same manner as in the first embodiment to perform instantaneous interruption switching. be able to. The phase adjustment unit 112 or 113 can adjust the signals of both systems to have the same phase based on the phase difference A of both systems detected by the phase difference detection unit 21.

As described above, according to the second embodiment, the phase difference between the two systems can be detected by using the CRC extraction unit instead of the MF extraction unit 12 and the like in the first embodiment. Instantaneous interruption switching can be performed in the same manner as in 1.

Embodiment 3 FIG. 3 shows a hitless interruption switching circuit according to Embodiment 3 of the present invention. 3 that have the same reference numerals as those in FIG. 1 have the same functions, and a description thereof will be omitted. 3, reference numeral 32 denotes an all-bit extracting unit provided in place of the MF extracting unit 12 of the first embodiment shown in FIG. 1, and 33 denotes a MF extracting unit 13 of the first embodiment shown in FIG. Instead, an all-bit extracting unit 31 provided for each of the two systems based on the bit at a predetermined position extracted by the all-bit extracting units 32 and 33 and the threshold value B set by the threshold value setting unit 14. This is a phase difference detection unit that detects the phase difference A.

In the third embodiment, the phase difference between the two systems is obtained by extracting all the bits of the signals of both the systems based on the bit indicating the head of the frame and comparing predetermined bit positions. be able to. After detecting the phase difference A between the two systems, the phase difference detection unit 31 calculates
And the phase adjusters 109 and 11 as in the first embodiment.
0 can be controlled to perform instantaneous interruption switching. The phase adjustment unit 112 or 113 can adjust the signals of both systems to have the same phase based on the phase difference A of both systems detected by the phase difference detection unit 31.

As described above, according to the third embodiment, the phase difference between the two systems can be detected by using the all-bit extracting unit instead of the MF extracting unit 12 and the like in the first embodiment.
Instantaneous interruption switching can be performed in the same manner as in the first embodiment.

Embodiment 4 FIG. 4 shows a hitless interruption switching circuit according to Embodiment 4 of the present invention. 4 that have the same reference numerals as those in FIG. 1 have the same functions, and a description thereof will be omitted. 4, reference numeral 15 denotes a threshold value extraction unit provided in place of the threshold value setting unit 14 of the first embodiment shown in FIG. 1, and 41 denotes an MF extracted by the MF extraction units 12 and 13. A phase difference detection unit that detects a phase difference A between the two systems based on the threshold value B extracted by the threshold value extraction unit 15.

The threshold value extracting section 15 stores a threshold value (a phase difference at which the maximum phase of the opposing transmission device 119 can be adjusted) at a predetermined position such as an empty bit in a signal transmitted from the opposing transmission device 119. Is set and sent, the threshold value can be extracted. Therefore, while the threshold value B of the first embodiment is fixedly set, the threshold value of the fourth embodiment can be variably set. Since the transmitted threshold value is the same in both the 0-system and the 1-system, as shown in FIG.
It suffices that only either (C1) from the F unit 104 to the threshold value extracting unit 15 or (C2) from the IF unit 105 to the threshold value extracting unit 15 be connected. The phase adjustment unit 112 or 113 can adjust the signals of both systems to have the same phase based on the phase difference A of both systems detected by the phase difference detection unit 41.

As described above, according to the fourth embodiment, the threshold value can be variably set by using the threshold value extraction unit instead of the threshold value setting unit 14 of the first embodiment. Using this variable threshold value, the phase difference between the two systems can be detected, and instantaneous interruption switching can be performed as in the first embodiment.

Fifth Embodiment FIG. 5 shows a hitless interruption switching circuit according to a fifth embodiment of the present invention. In FIG. 5, components denoted by the same reference numerals as those in FIGS. 1 to 4 have the same functions, and a description thereof will be omitted. In FIG. 5, the range surrounded by reference numeral 50 is the MF phase difference detection unit according to the first to fourth embodiments, and the phase adjustment units 109a, 110a, 112a, and 1
13 shows a non-instantaneous-interruption switching circuit according to the fifth embodiment with the addition of 13a.

Although the phase adjusters 109, 110, 112, and 113 shown in FIGS. 1 to 4 have a memory (not shown) having a predetermined capacity, the phase adjusters 109, 110, 112, and 113 have a limited capacity. There is a certain limit on the phase difference. Phase adjustment section 109a (0 transmission phase adjustment section), 110a (1 transmission transmission phase adjustment section), 112 according to the fifth embodiment.
The memory cards (not shown) a (a phase adjustment unit of system 0) and 113a (phase adjustment unit of system 1) are detachable memory cards. For this reason, by using a memory card having a large capacity or by sequentially changing the memory card as needed, the transmission device
The phase difference of the maximum value at which the phase can be adjusted in step 19 can be variably set, and it is possible to flexibly cope with a change in the phase difference between the two systems.

As described above, according to the fifth embodiment, since the memory units (not shown) of the phase adjustment units 109a, 110a, 112a, and 113a can be detachable memory cards, the memory cards can be appropriately replaced. By doing so, it is possible to variably set the phase difference of the maximum value at which the phase can be adjusted in the opposite transmission device 119.

[0040]

As described above, according to the instantaneous hitless switching circuit or method of the present invention, by using the phase difference capable of instantaneous hitless switching in the opposing transmission apparatus as the threshold value, the opposing transmission is realized. When fully using the instantaneous interruption switching function of the device and expanding the guaranteed range of the phase difference between the two systems that can be instantaneously switched, change the instantaneous interruption switching circuit of both opposing transmission devices. Without accompanying, it is possible to provide a non-instantaneous interruption switching circuit or method that can be dealt with by changing only the non-instantaneous interruption switching circuit of one of the transmission devices.

[Brief description of the drawings]

FIG. 1 is a diagram showing an instantaneous interruption switching circuit according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an instantaneous interruption switching circuit according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an instantaneous interruption switching circuit according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a hitless interruption switching circuit according to a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating an instantaneous interruption switching circuit according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional instantaneous interruption switch circuit between transmission apparatuses.

[Explanation of symbols]

10, 20, 30, 40, 111, 127 MF phase difference detector, 11, 21, 31, 41 phase difference detector,
12, 13 MF extraction unit, 14 threshold value setting unit,
15 threshold value extraction unit, 22, 23 CRC extraction unit,
32, 33 all bit extraction unit, 101, 119 transmission device, 102, 103, 104, 105, 120, 1,
21, 122, 123 IF section, 106, 108, 1
24, 126 MF insertion part for instantaneous interruption switching, 107, 1
25 MF generator for instantaneous interruption switching, 109, 110, 1
12, 113, 109a, 110a, 112a, 113
a, 128, 129 Phase adjustment unit, 114, 130
Switching unit, 115, 116, 117, 118 Transmission path.

Claims (7)

[Claims] An instantaneous interruption switching circuit on the transmission device side, which performs instantaneous interruption switching between a system 0 and a system 1 between a transmission device and a transmission device opposed to the transmission device, A 0-system pattern extraction unit for extracting a transmission unit having a predetermined bit pattern from the 0-system signal received from the opposite transmission device, and a predetermined bit pattern from the 1-system signal received from the opposite transmission device A 1-system pattern extraction unit for extracting a transmission unit, a phase difference setting unit in which a predetermined phase difference indicating a range in which the non-instantaneous interruption can be switched in the opposed transmission device is set, and a 0-system pattern extraction unit A phase difference between the 0-system signal and the 1-system signal is detected based on the extracted transmission unit and the transmission unit extracted by the 1-system pattern extraction unit. Location set in the phase difference setting section And a phase difference detecting section that outputs the phase difference that has exceeded the phase difference as a phase adjustment of a signal transmitted to the opposite transmission device when it is determined that the phase difference exceeds the phase difference. Instantaneous interruption switching circuit. 2. The transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit are multi-frames used for non-stop switching, and the phase difference detection unit Is detected by the multi-frame extracted by the 0-system pattern extraction unit and the 1
2. The instantaneous interruption-free switching circuit according to claim 1, wherein the phase difference is a phase difference between the multi-frame extracted by the system pattern extraction unit. 3. The transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit each include a cyclic redundancy check code added to a signal received from the opposite transmission device. Wherein the phase difference detected by the phase difference detecting unit is the position of the cyclic redundancy check code extracted by the pattern 0 extraction unit and the position of the cyclic redundancy check code extracted by the pattern extraction unit 1 2. The instantaneous interruption-free switching circuit according to claim 1, wherein 4. The transmission unit extracted by the 0-system pattern extraction unit and the transmission unit extracted by the 1-system pattern extraction unit are each composed of all bits of a signal received from the opposite transmission device, The phase difference detected by the phase difference detection unit is determined by a predetermined bit position in all bits extracted by the 0-system pattern extraction unit and a predetermined bit in all bits extracted by the 1-system pattern extraction unit. 2. The instantaneous interruption-free switching circuit according to claim 1, wherein the phase difference is a phase difference between the position and the position. 5. The opposed transmission device set in the 0-system signal received from the opposed transmission device or the 1-system signal received from the opposed transmission device instead of the phase difference setting unit. A phase difference extraction unit for extracting a predetermined phase difference indicating a range in which instantaneous interruption switching is possible, wherein the phase difference detection unit uses the predetermined phase difference extracted by the phase difference extraction unit and the 0 system. 2. The instantaneous interruption-free switching circuit according to claim 1, wherein it is determined whether or not a phase difference between the first system and the first system exceeds the predetermined phase difference. 6. A phase adjusting unit of a transmission 0 system for adjusting a phase of a signal to be transmitted to the opposite transmission device based on the exceeding phase difference output from the phase difference detecting unit, A phase adjuster of one transmission system for adjusting a phase of a signal to be transmitted to the opposite transmission device based on the exceeding phase difference output from the detecting unit; and the excess output from the phase difference detecting unit. A phase adjustment unit of system 0 that performs phase adjustment of a signal used for instantaneous interruption switching of the transmission device based on the phase difference that has been detected, and based on the exceeding phase difference output from the phase difference detection unit. A phase adjuster of one system for adjusting a phase of a signal used for non-interruptible switching of the transmission device;
The phase adjustment unit of the transmission 0 system, the phase adjustment unit of the transmission 1 system, the phase adjustment unit of the 0 system, and the phase adjustment unit of the 1 system have a detachable recording unit. 6. The instantaneous interruption switch circuit according to any one of 1 to 5. 7. The communication between a transmission apparatus and an opposite transmission apparatus has a zero
An instantaneous interruption switching method on the transmission device side for performing instantaneous interruption switching between a system and a system, wherein a transmission unit having a predetermined bit pattern is determined from a 0 system signal received from the opposite transmission device. A 0-system pattern extraction step for extracting, a 1-system pattern extraction step for extracting a transmission unit having a predetermined bit pattern from a 1-system signal received from the opposite transmission device, and a 0-system pattern extraction step. A phase difference detecting step of detecting a phase difference between the system 0 and the system 1 based on the extracted transmission unit and the transmission unit extracted in the pattern extracting step for the system 1; When the determined phase difference is determined to exceed the predetermined phase difference indicating the range in which the instantaneous interruption switch can be performed in the opposite transmission device,
Outputting the phase difference exceeding the phase difference as a phase adjustment amount of a signal to be transmitted to the opposite transmission apparatus.