JPS6032455A - Synchronization switching system - Google Patents

Abstract

PURPOSE:To improve the reliability of a system by producing a master trigger signal from a transmission code processing section provided to an active system and outputting respectively a clock signal selected depending on a prescribed priority so as to apply the signal to a common signal generating circuit. CONSTITUTION:Switching devices 20-1-N and a test signal generating section 21 are connected to the digital multiplex conversion terminal equipment 19 of a sysnchronization switching system. Further, the system is provided with a transmission section spare system transmission code processing section 22, transmission code processing sections 23-1-N, a common signal generating section 24, a transmission synchronization switching section 25, a spare system transmitter 26 and transmitters 27-1-N. The system reception section is provided with the spare system receiver 26, receivers 29-1-N and a digital multiplex converting terminal station device 36 or the like. Further, in order to produce the master trigger signal from the active processing sections 23-1-N of the transmission section, a clock signal selected depending on a prescribed priority is outputted, the signal is fed to the generating section 24 so as to change over the active and spare system as required.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronous switching system, and more particularly to an improved VC system for synchronous switching between a working system and a protection system in a digital wireless transmission system VC.

In the digital wireless transmission system, operational countermeasures for active system VC'81: or 4. As a countermeasure against failures, one standby system is provided for each of the multiple active systems. In general, the current system to be switched is switched to the standby system for operation according to the situation. In the case of 0, the above-mentioned VC points out two reasons for cutting off the backup system I/C from the active system: operational countermeasures and equipment failure countermeasures for the active system V.

From the perspective of the actual operational status of the digital wireless transmission system, the former's switching absorption factor as an hr2, j branch is better than the latter's ψ factor as a factor of 7. This is by far the largest factor in terms of operational time compared to the change factor. Therefore, as an operational countermeasure for the digital wireless transmission system V, for example, the digital wireless transmission system V
During maintenance and inspection of the working radio line in C, or when taking measures against fading in this working radio line,
A synchronous switching method that allows switching between the active system and the standby system without momentary interruption is extremely important.

FIG. 1 is a block diagram showing the main parts of a transmitting side and a receiving side in a digital wireless transmission system Vζ to which a conventional synchronous switching system is applied. In FIG. 1, the current system (1) output from the digital multiplex conversion terminal equipment 1
Digital multiplexing No. 15 100-1 corresponding to ~(N)
~N are transmission code processing units 5- of the 6 active systems, respectively.
1 to NVC input. These transmission code processing units 5-1
~Nvc, the digital multiplexed signal 100-
1 to N, convert the bit rate of the digital multiplexed signals 100-1 to N through, for example, a buffer memory and a phase synchronization system corresponding to the clock signal, and -
! The master trigger signals 110-1 to 110-1 generated by the common signal generator 6V are inputted to synchronize all frame synchronization patterns corresponding to all working and system radio lines, and generate the bit rate. The frame synchronization pattern is added to the converted digital multiplexed signal to generate digital multiplexed signals 120-1 to N5 whose frames are phase synchronized between the respective current systems.

The corresponding transmission 1d devices 9-1 to NVC are output.

The transmitting devices 9-1 to 9-N of each active system input the corresponding digital multiplexed No. 100 No. 120-1 to Ni to which the above-mentioned frames have been added, and receive them through predetermined conversion means. A modulated signal is generated and transmitted from the receiving side. On the receiving side, from the corresponding receiving devices 11-1 to NVC of the current systems []] to (N),
All of the modulated simplified codes sent from the transmitting devices 9-1 to 9-N are received and demodulated to generate digital multiplexed signals i20-i to N.
k, and the corresponding reception synchronization switching unit 14-1
~ Output to N.

The reception synchronization switching units 14-1 to 14-N receive the input digital multiplexed signals 1.20-1 to 20-1 to Ni, and after establishing the frame synchronization ffi (fMi) in the radio section, the distributor 12vc similarly performs the (Multiplexing of standby system with frame synchronization of rift system 4g No. 1
30-1 to N are all inputted, a multiplexed signal of either the current or preliminary system is selected, and the reception code processing unit 15-1
~Output NVC. The reception code processing units 15-1 to 15-N remove the frame synchronization pulses, etc. by inverse rate conversion VC and Jlj, and convert the digital multiplier 11 (No. 100-1 to ~N is generated and output to the digital multi-jlJ conversion terminal device 18.

In such a digital wireless transmission system, for example, due to maintenance and operation requirements, inspection of wireless lines in prison systems, 'j' K &, 'J
-> As a replacement for the current system [2], the preliminary system 1iii
The system is switched over and used. At this point, do you want to switch from the current system [2] to the backup cystine? +
: ')Jl'. In order to operate without interrupting the entire current line, the conventional synchronous switching method VC is used to operate the current system [1] to (N) transmission/1 port code processing, ) 1 part 5. -1 to N, the bit rate converted and frame synchronization notation added digital multiplexed signals 120-1 to N, as described above, the respective corresponding transmitting devices 9-1 to At the same time, it is also sent to the transmission cycle switching unit 7v included in the backup system, and it is also sent to the D Part 6
The switching timing signal via both the specific mask trigger signal generated in the VC allows the system to switch instantaneously and without interrupting the working line, with perfect frame phase synchronization and in the fC state. . From the moment of this switching, the transmission code processing unit 5- of the current system [2]
2' VC input digital multiplexed signal 100-2
is the transmission synchronization switching unit 7, the pre-4ffi system transmission device t
It is inputted to the distributor 12 through all the ITS and standby system receivers 10, and from the predetermined switching timing signal V corresponding to the system switching 11. The reception synchronization switching unit 14-2 switches the current system [
2] is input to the received code processing unit 15-2. The above VC
At the same time, the transmitter synchronization switching section 7 and the reception synchronization switching section 14-
1-Switching action in NVC is usually caused by a concentration circuit.
T(j, depending on the child switch VC, and assuming an instantaneous switching function -1+" will not cause any problems. Receiving 1d code processing section 1
Regarding the effect VC of 5-2, as mentioned above, the existing VC-C
Ai).

In the %fljf'J system [2], by using the synchronous switching method as described above, the transmitting device 9-2 and the receiving device 11-2 can be switched without interfering with the current operation rate.
It is possible to carry out maintenance and inspections of unconventional lines, including:

In addition, as one of the problems with line deterioration caused by fading V, which is a radio wave propagation problem in wireless line VC, for example, the transmitter 8 and the receiver that form one unresolved curve of the backup system. 10Thi Space Diaperity Transmission/Reception 1 River device, Iso r+I = '3, one system in the current system rc/no] Corresponding to the deterioration of the gas line quality, the self-end or hand 7iiυV this η, within the current system. When one system immediately switches the VC backup system VC9J to secure a line, the above-mentioned synchronous switching method is used as an effective VC.

In addition, in FIG. 1, the switching devices 2-1-N and 16-
1'-N is a switching device for temporarily switching to a standby system when a certain current system VC failure fc occurs in the current systems (1) to [N. In addition, the functions of the test signal source generation section 3 and the test number 100 detection section 15 are such that the functions of the backup system, which is one of the main elements for forming the synchronous switching method, are transferred from the current system [1] to [N ) The test signal generated in the test signal generator 3 VC inputs the mask clock signal 150 from the common signal generator 6 and is transmitted to each active system V. After synchronization, the backup system sender code processing unit 41 generates the digital pseudo multiplexed signal 160.
/c is input. In the backup system transmission code processing unit 4, a signal is generated using the digital pseudo multi-freezing signal 160 and an external master clock signal 180 synchronized with the current [l] to CN) system in the common signal generation circuit 6V. The mask trigger No. 3 110-0 is input, and the digital multiplexed signal 120-(l generate,
The transmission synchronization switching unit 7 outputs the output to the “transmission Jv” switching unit 7. The transmission synchronization switching unit 7 outputs the VC1 standby system to the active system It
With the exception of the case 7 in which the digital multiplexed signal 120-0 is operated as the i#i system transmitter 8, the digital multiplexed signal 120-0 acts as , the digital multiplexed signal 120-0 is sent to the preliminary system transmitting device 8, the preliminary system receiving WrS device i!, I
The test signal detecting section 16VC is manually inputted as a digital pseudo-multiplex signal 170 for testing through the Os distributor 12 and the backup system Ai et al. It is determined whether or not the common signal generating circuits 6r, j: and the current system (1) to [~] are in synchronization with 1 and the external i:l (driven by the master clock signal 180K). b?Jl
'ul master clock 4g 15o> and master trigger signals 110-1 to 110-N are generated, and the backup system transmission code processing unit 4 and the active system transmission code processing unit 5-
1 to N(7)71/-m phase synchronization is attempted.

However, in the conventional synchronization cutoff method described above,
At present, the digital multiplexed signals 120-1 to 120-N to which the bit rate has been converted and all frame synchronization patterns have been added correspond to each wireless line in the current system [1] to (N) VC.
The master trigger signals 110-1 to 110-N for obtaining frame phase synchronized sound are generated using only the external mask clock signal 180 inputted in the common signal generating section 5 as a reference, and are based on each transmission code of each current system. Processing section 5-1-
NK has been sent. For this reason, the common signal generating section 6
The external mask clock signal 180 at V VC
If a failure occurs, the VC will not be able to fully perform its functions with the synchronous switching method, and the seamless switching between the active system and the standby system, which is required for system operation, will become impossible. Radio 1 mentioned above! ,! In addition, it becomes impossible to apply countermeasures against fading to untethered lines, and as a result, the reliability related to the operation of the entire digital wireless transmission system is reduced. It has the disadvantage of lowering

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to improve the transmission side VC in a digital wireless transmission system VC,
A method for extracting and selecting a clock signal from a digital multi-JR signal manually, and a method for generating a preliminary mask clock signal.
It is an object of the present invention to provide a synchronization cutoff system that significantly improves the reliability of digital wireless transmission system VC.

The uninvented synchronous switching method is: ``t, for N (equipment e > system and backup system, !J hy, 6
Digital radio transmission method 2 A synchronous switching method is formed as a general target.In this case, for the purpose of synchronous switching between the active system and the standby system, an IT (positive integer less than or equal to N) system V is used. The mask clock extraction stage extracts n mask clock signals from the multiplexed signal input.
A specific mask Torino J(, 1 for generating the
Time-determined mask clock j, H > -5 points Y and the preceding order VC Therefore, the +1 mask -7 "mask clock to select from among the 1st signal (fi selection means and all configured.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a diagram showing the main parts of a digital wireless transmission system to which an embodiment of the invention is applied. As shown in FIG. 2, the digital wireless transmission system to which the inventive Mt example is applied is a digital multiplex exchange
9, off (4 units 20-1 to 20-N, test double generator 21, backup system transmission 1 error code processing unit 22, transmission code processing unit 23-1 to 23-1, common signal generation full 24) , the transmission synchronization switching unit 25, the backup system transmission length [:26, and the transmission 15
The devices 27-1 to 27-N, the backup system receiving device 28, the receiving devices 29-1 to 29-N, the distributor 30, the backup system reception code processing unit 31, and the receiving percentage synchronization cutting units 32-1 to N. ,
Key code processing units 33-1 to N,! :, the test signal detection section 34, the switches 35-1 to 35-N, and the digital multiplex conversion terminal device 36 are installed.

A practical example of the 44 system of the present invention shown in FIG. 2 VC is applied to the digital; 1111” with the digital wireless transmission method to which the Nori-Kai method is applied.
It is clear from the comparison of Figures 1 and 2 that the 15 points are 7 VC%, i↓ In Figure 2 VC, the current system
]~[Isu VC4fN transmission code processing section 23-1
~ +1 to generate all master trigger signals li)
＞The clock that should be selected according to the priority after the fart,
150-1 to n are output respectively, and the common 11<
0 which is sent to the generation circuit 24, that is,
In the digital wireless transmission system V to which an embodiment of the synchronous switching system of the present invention is applied, select a predetermined n system among the systems for use in (1) and (1). For example, in VC, the current system [1] to [Isu],
A master trigger signal corresponding to the internal VC% of the transmission code processing units 23-1 to 23-n provided in each of the current systems [1] to (n), and a master trigger signal It is equipped with a means for extracting a clock signal sound that is a reference for generation, and the generated clock signal sound is transmitted to the transmission code processing unit 2.
Clock signals 150'-1~ output from 3-1~n
n are both sent to the common signal generator 24. These clock signals 150-1 to 150-n are inputted to the common signal generator 23V, and one of them is selected and acts as mask clock No. 11,
At this time, a master trigger signal is generated. Other clock signals are generated by the common signal generator 24.
It stays in the state where VC is input. However, in response to the above-mentioned operational requirements, the current system
/(Under the switching situation, if a failure occurs in the mask clock signal generating means 23 generated inside the common 100 generator 23, which is originally the reference for generating the master trigger signal) In the state VC, C1 is the clock signal 150-1 to n inputted to the common signal generating section 24.
The operation of the clock 111 selection means for selecting a specific clock signal from among them according to a predetermined priority order,
Select all of the specific clock signals.

This mask clock signal? ! 1' Mask as standard
All trigger signals are generated and sent to the transmission code processing units 23-1 to 23-N of each active system. In this way, the current system V
A predetermined number of transmission code processing units from among the transmission code processing units provided in C are transmitted, and a clock signal is generated from the corresponding digital multiplexed signal within each of these predetermined number of transmission code processing units. It is provided with means 1 for extracting the clock information, and also has a fixed priority r of %J from among the clock information, so that the master
Clock 1. koυ'a: , 1:! ! i Jl<'J
Therefore, it is preferential to select a clock signal that is present in JL-(or 7t), so that even if the 11F of the clock signal source of C is interrupted, immediate VC support is available.
2) Select a spare clock signal that can be used to generate a mask trigger signal for each transmission of the active system. 'blasphemy'
j: It is possible to send the number processing unit V. This p clock signal: ”'+ l-F I50 ! - Preliminary 1 related to n
1iii mask clock i, No. 1 gold] Eight selection T, VC Tsutsu other than 6 action, condolence] 1'/! ,ll'ko small+%
jl、ru+m The conventional synchronous switching method described above is now in use.
This is the same as in the 7'4 digital wireless transmission system.

In addition, in the case of the above vc, the uninvented --) 4.1iit
The effect of the invention has been explained with reference to the case where the wireless line is one section as the area of the digital wireless transmission system to which Example i is applied. However, as the digital wireless transmission system to which the present invention is applicable, Needless to say, this is not something that can be used for just one section.

Further, even though the method of forming the mask clock extracting means and the mask clock selecting means, which is an essential requirement for non-invention, is not limited to the method of forming the mask clock extracting means and the mask clock selecting means in the above-mentioned embodiment.

As explained in detail above, the present invention is applicable to the operational requirements of VC in digital wireless transmission system VC.
Instantly disconnects the connection between the active system and backup system.
With regard to the master trigger signal required for the kth ironing, the mask trigger selection means has the effect of significantly reducing the lag of the digital wireless transmission system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main part of a digital wireless transmission system to which the synchronous switching system of the iJ-US example is applied;
FIG. 2 is a block diagram showing the main parts of a digital wireless transmission system to which an embodiment of the present invention is applied. In the figure, ], 18, 19. 36... digital multiplex conversion terminal equipment, 2-1 to N, 17-1 to N, 20-1 to N
, 35-1~]N...switcher, 3.21...
・Test signal source generation section, 4, 22...Prediction system transmission code processing section, 5-1 to N, 23-1 to N...Transmission 1B code processing section, 6.24. ... Common signal generation section, 7.25 ... Transmission synchronization support section %8.26 ...
...Backup system transmitter, 9-1~N, 27-1~N
・・・・・・Transmission wave ft%10, 28・・・Spare system receiver 13→hat i:tb 11-1~N, 29-1~
N... Receiving device, 12.30...Distributor, 1
3.31... Backup system/reception code processing section,
14-1 to N, 32-1 to N...Receive D synchronization cutting section, 15-1 to N, 33-1 to N...Reception code processing section s], 6. 34...Test 1, No. f detection section.

Claims (1)

[Claims] A digital radio transmission system consisting of a working N (larger than 1 &! 1.) system and a standby system. For the purpose of replacement, the current n (positive manufactured number less than or equal to N) system is
Digital multi-stop signal human power! A mask clock extraction means for extracting Jn mask clock signals, and a frame of a famous system that receives the n mask clock signals and encloses the active and backup systems. VC) Jl ft+lJ・It
'<r constant master・) IJ The master clock signal sound for IJ (it number ke generation - ship') is given a constant priority +111'1st PC, therefore r'frJ-0 The synchronous switching method is characterized in that it is possible to select a mask clock signal selection means which selects i'ArJ+ from among the mask clock signals.