JPH0691515B2 - Digital multiplex communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention is used for the construction of a bidirectional digital multiplex communication system, and in particular, the method for protecting and switching a digital signal to be transmitted at the time of occurrence of a fault is advanced, The present invention relates to a digital multiplex communication system for improving the efficiency of use of the multiplex communication system.

〔Overview〕

The present invention is a bidirectional digital multiplex communication system in which two transmission paths for transmitting a high-speed digital signal in which a plurality of digital signals are multiplexed are provided in one direction, and low-speed digital signals are input to the transmitting side and the receiving side, respectively. A cross point switch that performs predetermined switching is provided, and normally two transmission lines are fully used to transmit signals, and when one of the two transmission line systems becomes an obstacle,
By setting and controlling the switching state of the crosspoint switch so that a high-priority signal is transmitted through a transmission line system that does not cause a failure, economical and efficient use of communication equipment at normal times and failure It is intended to be compatible with the protection measures at the time.

[Conventional technology]

Two typical examples of this type of digital multiplex communication system according to the prior art are shown in FIG. 2 and FIG. 2 and 3, only one direction in the bidirectional or one-way communication system will be described.

In the first conventional example shown in FIG. 2, n (n is a natural number of 2 or more) transmission low speed input signal a _1i ~a _ni of is inputted, the same in each distribution unit A _1t to A _nt, two by two Is divided into signals. Therefore, the same signals p _t and q _{t as the} low-speed transmission input signals a _{1i to} a _ni are input to the multiplex transmission units 5 and 6,
The same high-speed digital signals are sent from the multiplex transmission units 5 and 6 to the transmission lines 15 and 16, respectively.

On the receiving side, the reception separation units 7 and 8 separate the reception signal into a plurality of low-speed digital signals p _r and q _r .
From the signals p _r and q _r , one low-speed digital signal is sequentially input to the selection units A _1r to A _nr , where the input signal having no code error is selected and the received low-speed output signal a _1o
It is output as ~ a _no .

Therefore, the transmission low-speed input signals a _{1i to} a _ni are distributed to the distribution units A _{1t to Ant.}
To the receiving side selection units A _{1r to} A _nr are transmitted via completely double paths, and the multiplex transmission unit 5 on the way.
And 6, even if a failure occurs in one of the transmission lines 15 and 16 or the reception separation units 7 and 8, a normal signal can be transmitted to the receiving side.

In the second conventional example shown in FIG. 3, the low-speed transmission input signals a _{1i to} a _ni are directly used as the signal p input to the multiplex transmission unit 5, and are transmitted from the multiplex transmission unit 5 to the transmission line 15. On the reception side, the reception separation unit 7 separates the low-speed digital signal p _r and outputs the received low-speed output signal a _{1o to} a _no . Similarly, for the second transmission line 16, the transmission low-speed input signals a _{(n + 1) i to} a
_2ni passes through a single multiplex transmission unit 6, transmission line 16 and reception demultiplexing unit 8 and then at the reception side, reception low-speed output signals a _{(n + 1) o to} a _2no.
Is output as.

Thus, the second conventional example shown in FIG. 3 can transmit twice as much information as the first conventional example shown in FIG.

[Problems to be solved by the invention]

However, in the first conventional example of FIG. 2, it is necessary to have a multiplex transmission section, a transmission line, and a reception / separation section each having a communication capacity twice as high as the total information rate of the original signals to be transmitted, which is extremely high. It has the drawback of being uneconomical.

On the other hand, in the second conventional example of FIG. 3, although an economical structure can be adopted, if a failure occurs even at one location in the multiplex transmission section, the transmission line, and the reception / separation section, the failure section should be passed. Since the signal has no alternative transmission path,
It has the drawback of being completely rejected.

As described above, in the conventional digital multiplex communication system as shown in FIG. 2 or 3, it is possible to achieve both economical and efficient utilization of communication equipment and securing of protection means against failure occurrence. There is a drawback that cannot be done.

An object of the present invention is to provide a digital multiplex communication system capable of achieving both economical and efficient utilization of communication equipment and securing of protection measures against failure occurrence by eliminating the above-mentioned drawbacks. is there.

[Means for solving problems]

The present invention is a bidirectional digital multiplex communication system provided with two transmission paths for transmitting a high-speed digital signal in which a plurality of low-speed digital signals are multiplexed, one for each direction, in which the transmission side inputs a low-speed transmission input signal. A first crosspoint switch that performs a predetermined switching, a first control unit that sets a switching state of the first crosspoint switch, and a part of a plurality of output signals from the first crosspoint switch. It is provided with two multiplex transmitters, each of which is input, multiplexed into a high-speed digital signal, and output to each transmission line,
The receiving side receives two high-speed digital signals from each of the transmission lines and separates them into a plurality of low-speed digital signals, and outputs the output signals from the respective reception / separation units to perform predetermined switching and perform a plurality of switching operations. A second crosspoint switch that outputs a reception low-speed output signal, and a second control unit that sets the switching state of the second crosspoint switch, the first and second control units are each control information. The first control unit on the transmitting side sets the switching state of the first crosspoint switch to have a high priority when one of the two transmission systems is in a failure state. The second control unit on the receiving side is provided with a means for controlling the signal to be transmitted by another transmission system, and the second control unit on the receiving side uses the control information from the first control unit on the transmitting side to determine whether one transmission system is in a failure state. When the other Characterized in that it comprises means for setting the switching state of the second crosspoint switch so as to output a transmission signal transmitted priority in system as a slow output signal.

[Action]

The first and second crosspoint switches normally use two transmission lines to multiplex and transmit n low-speed digital signals per transmission line. Then, when a failure occurs in the transmission line system including one of the multiplex transmission unit, the transmission line, and the reception separation unit, the priority of the 2n transmission low-speed input signals input to the first crosspoint switch The high n signals are selectively switched, and are transmitted to the receiving side by the transmission path system having no fault, and the second crosspoint switch performs the same selective switching as the first crosspoint switch. It is output as the received low-speed output signals.

Therefore, normally, the communication equipment is fully used for signal transmission, and in the event of a failure, important signals with high priority can be transmitted without interruption. Economical and efficient use of the communication equipment and protection against failure occurrence It is possible to achieve both securing of means.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

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

In this embodiment, transmission lines 15, 16, 17 for transmitting a high speed digital signal in which a plurality of low speed digital signals are multiplexed, and
In a bidirectional digital multiplex communication system with two 18s in each direction, in the case of transmission from the right to the left, the transmitting side has 2n (n is a natural number) low-speed input signal a _1i
The first crosspoint switch 1 for inputting ~ a _ni and performing predetermined switching, and the first crosspoint switch 1
Of the 2n output signals from the first cross-point switch 1 and the first control unit 13 for setting the switching state of n, and respectively input n signals p _t and q _t to multiplex them into a high-speed digital signal. The multiplex transmission units 5 and 6 for outputting to the respective transmission lines 15 and 16 are provided, and the receiving side receives the high-speed digital signals from the respective transmission lines 15 and 16 and outputs n low-speed digital signals p _r. 2 q receiving low-speed output signals a _1o ... are input by inputting the output signals p _r and q _r from each of the receiving separation units 7 and 8 and the two receiving separation units 7 and 8 which are separated into q _r and q _r. The second cross point switch 2 that outputs a _2no and the second control unit 14 that sets the switching state of the second cross point switch 2 are provided, and the first and second control units 13 and 14 are As a means of communicating control information with each other It includes transmitting and receiving means of the control information k ₁ and k ₂ of.

Similarly, in the case of transmission from the left direction to the right direction, the first crosspoint switch 4, the multiplex transmission units 11 and 12,
The transmission lines 17 and 18, the reception separation units 9 and 10, the second crosspoint switch 3, the first control unit 14 and the second control unit 13 are provided, and the transmission low-speed input signals b _{1i to} b _2ni are provided. _Is transmitted and the received low speed output signals b _{1o to} b _2no are output. Note that r _t and s _t are signals input to the multiplex transmission units 11 and 12, r _r and s _r are signals output from the reception demultiplexing units 9 and 10, l ₁ and l ₂ are control information, and c ₁
And c ₂ are control signals for the crosspoint switches 1, 3 and 2, 4 respectively.

In addition, in the switching state of the crosspoint switches 1 and 4, 2n input signals are normally all output during normal operation, and at the time of a failure, n high-priority signals out of 2n are transmitted without failure. It is set to be sent to the multiplex unit of the road system. On the other hand, crosspoint switches 2 and 3
The switching state is set so that normally 2n input signals are output as 2n output signals, and n input signals are output as predetermined output signals when a failure occurs.

The feature of the present invention resides in that, in FIG. 1, crosspoint switches 1, 2, 3 and 4 and control units 13 and 14 are provided.

Next, the operation of this embodiment will be described.

The low-speed transmission input signals a _{1i to} a _2ni are first input to the crosspoint switch 1. The crosspoint switch 1 has means for connecting a signal from an arbitrary input terminal to an arbitrary output terminal. The output of the cross point switch 1 is such that half of the n signals p _t are sent to the multiplex transmission unit 5 and the other half of the n signals p _t.
The individual signals q _t are respectively input to the multiplex transmission unit 6, where they are multiplexed and then transmitted to the transmission lines 15 and 16.

In the receiving / separating units 7 and 8, the signals from the transmission lines 15 and 16 are separated into low-speed digital signals, and n signals p _r and q _r are given to the crosspoint switch 2. Received low-speed output signal from crosspoint switch 2
Outputs a _{1o to} a _2no .

Similarly, low-speed transmission input signals b _{1i to} b _2ni are input to the transmission side in the reverse direction, and the cross point switch 4 and the multiplex transmission unit are input.
11 and 12, transmission lines 17 and 18, reception separation units 9 and 10
Then, the signal passes through the cross point switch 3 in this order and is re-outputted as the reception low-speed output signals b _{1o to} b _2no on the reception side.

The control units 13 and 14 include the crosspoint switches 1, 2,
Controls the setting state of switches inside 3 and 4.

Under normal conditions, that is, when there is no obstacle in any part of this digital multiplex communication system, the transmission low-speed input signal a _1i is transmitted to the reception low-speed signal a _1o , the transmission input signal a _2ni is transmitted to the reception low-speed output signal a _2no , and the transmission low-speed signal is transmitted. The input signal b _1i is the received low-speed output signal b
_The transmission low-speed input signal b _2ni is transmitted to _1o and the reception low-speed output signal b _2no is transmitted, and 2n low-speed digital signals are transmitted per one direction.

On the other hand, if a failure occurs in part, for example, if the transmission line 15 is disconnected or if the receiving / separating unit 7 fails, all the signals p _t input to the multiplex transmitting unit 5 are not transmitted to the receiving side. The signal q _t input to the multiplex transmission unit 6 is normally transmitted to the reception side and output from the reception separation unit 8 as a signal q _r . At this time, in the crosspoint switch 1, one of the transmission low-speed input signals a _{1i to} a _2ni having the highest priority n
Only the individual signals can be selected and given to the multiplex transmission unit 6 as the signal q _t . The selected n signals q _t can be output to any output terminal by the cross point switch 2 on the receiving side. Therefore, when the control units 13 and 14 match the setting states of the crosspoint switches 1 and 2 with the control information k ₁ and k ₂ and the control signals c ₁ and c ₂ , the above n high-priority transmissions are transmitted. The low speed input signal is obtained from the original receiving output terminal.

With respect to signal transmission in the reverse direction, the same operation can be performed by the crosspoint switches 3 and 4, the multiplex transmission units 11 and 12, the reception separation units 9 and 10, and the control units 13 and 14.

〔The invention's effect〕

As described above, according to the present invention, 2n transmission low-speed signals are normally transmitted by the crosspoint switch, and n high-priority transmission low-speed signals are transmitted by the transmission path system which does not cause a failure at the time of failure. By making it possible to transmit, the economical and efficient use of communication equipment at normal times,
There is an effect that it is possible to achieve both switching protection for a high-priority signal when a failure occurs.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a block diagram showing a first conventional example. FIG. 3 is a block diagram showing a second conventional example. 1,2,3,4 ... Cross point switches 5,6,
11, 12 ... Multiplexing unit, 7, 8, 9, 10 ... Receiving / separating unit, 13, 14 ... Control unit, 15, 16, 17, 18 ... Transmission line, A
_{1t to Ant} ...... Distribution unit, A _{1r to Anr} …… Selection unit, a _1i , a _ni , a
_{(n + 1) i} , a _2ni , b _1i , b _2ni ...... Sending low speed input signal, a _1o ,
a _no 、 a _{(n + 1) o} 、 a _2no 、 b _1o 、 b _{2no ・ ・ ・} Reception low-speed output signal, c ₁ , c _{2 ・ ・ ・} Control signal, k ₁ , k ₂ , l ₁ , l ₂ ...... Control Information, p _t , p _r , q _t , q _r , r _t , r _r , _st , s _r ... signal.

Claims (1)

[Claims] 1. A transmission path for transmitting a high-speed digital signal in which a plurality of low-speed digital signals are multiplexed is provided in two directions per direction.
In the bidirectional digital multiplex communication system provided with the present invention, the transmitting side inputs a low-speed transmission input signal and performs a predetermined switching, and a first crosspoint switch that sets a switching state of the first crosspoint switch. The receiving side is provided with one control unit and two multiplex transmission units for respectively inputting a part of the plurality of output signals from the first crosspoint switch, multiplexing them into a high-speed digital signal, and outputting each to each transmission line. Are two receiving / separating units for respectively receiving the high-speed digital signals from the respective transmission lines and separating them into a plurality of low-speed digital signals, and inputting the output signals from the respective receiving / separating units and performing a predetermined switching to obtain a plurality of receiving low-speed signals. A second cross point switch that outputs an output signal; and a second control unit that sets the switching state of the second cross point switch, And the second control unit includes means for mutually transmitting control information to each other, and the first control unit on the transmission side is configured such that when one of the two transmission systems is in a failure state, the first crosspoint switch And a means for controlling a signal having a high priority to be transmitted by another transmission system, and the second control section on the receiving side is provided with the first control section on the transmitting side. The control information is used to set the switching state of the second cross point switch so that when one transmission system becomes a failure state, the signal preferentially transmitted by the other transmission system is output as a low speed output signal. A digital multiplex communication system comprising means.