JPH047863B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] When switching to a backup device due to a failure in the current device,
It automatically switches the function of the decoder or encoder in the standby device so that signal processing continues in the code format that corresponds to the code format of the signal being processed by the active device, and thereby , a single standby device can handle multiple active devices that process signals of different code formats.

[Industrial application field]

The present invention relates to a working/standby switching system that allows communication to be continued by switching to a standby device in the event of a fault in the working device.

In wireless communication systems, since data is modulated and transmitted, NRZ codes are generally used because they have few high frequency components and are advantageous in terms of required bandwidth. On the other hand, in the baseband transmission system, the ANI of the RZ code is
(Alternate Mark Inversion) codes are often used.

Furthermore, in a system where transmission information such as a series of "0"s is generated, it becomes difficult to extract the timing on the receiving side. Therefore, as a "0" continuous suppression code, BnZS (Bipolar with n Zeros) is used to convert n bits of consecutive "0" into a special pattern.
Substitution) code is used.

HDB3 (High Density Bi-
polar3) codes are also known.

Therefore, in the wireless transmitter/receiver section, the NRZ code for wireless communication, the AMI code for baseband transmission,
Generally, it has a function to convert to BnZS code, HDB3 code, etc. In addition, in various systems, when there is a failure on the active side, the reliability of the system is improved by switching to the backup side and continuing processing such as communication, and there are two types: the system backup method and the set backup method. There is. The former system backup method is a method in which a backup system using another radio frequency is prepared in advance in addition to the current system, and in the event of a failure of the current system, the system is switched to the backup system in units of a predetermined section. The set backup method is a method in which a backup device is prepared for each device that makes up the system, and when a failure occurs, switching to the backup device is performed.

In a wireless communication system using such a working/protection switching system, the code format for BBS transmission is generally unified. However, in order to use a code format that is optimal for the characteristics of the transmitted information, there are cases where a different code format is used for the current device. Even in such a wireless communication system, it is desired to be able to economically switch between working and standby.

[Conventional technology]

In wireless communication systems, as mentioned above,
For example, if the code format on the baseband transmission side is
The AMI code is unified to the AMI code, and in the wireless transmitter, the AMI code is converted to an NRZ code by a decoder, and the code is modulated and transmitted according to a modulation method such as quadrature phase keying or multi-level QAM. In the radio receiving section, the received signal is demodulated, and the demodulated NRZ code is converted into an AMI code by an encoder and sent to the line.

[Problem that the invention seeks to solve]

As described above, the AMI code, in which pulses of positive polarity and pulses of negative polarity are alternately generated every time a "1" occurs, is sufficient for transmission information in which a long period of "0" does not occur. However, for transmission information where "0" continues for a long period of time, the timing cannot be extracted on the receiving side using only the AMI code.
It is desirable to convert the n-bit "0" into a BnZS code that converts the n bits of "0" into a special pattern including a positive polarity pulse and a negative polarity pulse when a predetermined number n of consecutive "0" bits occur. Therefore, even in wireless communication systems, current devices with different code formats are used.

In a wireless communication system where the code format is unified, as mentioned above, it is possible to provide one standby device for multiple working devices and apply the N:1 working/standby switching method. However, for a plurality of active devices with different code formats, unless a backup device is provided corresponding to the code format, it is not possible to switch between the active and backup devices, which has the disadvantage of increasing the system scale.

SUMMARY OF THE INVENTION An object of the present invention is to enable a single standby device to apply a working/standby switching method to a plurality of working devices with different code formats.

[Means for solving problems]

In the working/backup switching method of the present invention, a decoder that can switch and set functions according to the code format constitutes a system of a working device and a standby device equipped with an encoder, as shown in FIG. I will explain. Active equipment 1a, 1b, 2a, 2b and backup equipment 3a,
3b is provided with a decoder 4 or an encoder 5 that decodes or encodes the code format set by the setting information, respectively, and the preliminary devices 3a and 3b are provided with a decoder 4 or an encoder 5 that performs decoding or encoding of the code format set by the setting information. Alternatively, a selector 6 added to the encoder 5 is provided. When a failure occurs in the active device, the switching circuits 7a and 7b switch the connection from the active device to the backup devices 3a and 3b according to the switching signal, and transfer the setting information of the active device to the backup device 3 via the selector 6.
In addition to the decoder 4 or encoder 5 of 3b, the signal in the code format processed by the current device is applied from the hybrid circuit 8 to the standby device 3a via the switching circuit 7a, and the signal is processed in the same code format as that of the current device. The decoder 4 decodes and transmits the data, and the encoder 5 of the standby device 3b performs encoding in the same code format as the current device, and then sends it out from the switching circuit 7b via the hybrid circuit 8.

[Effect]

In the current devices 1a, 1b, 2a, 2b, the decoder 4 and encoder 5 perform decoding processing and encoding processing corresponding to the code format according to the setting information,
For example, from the active devices 1a and 1b to the backup device 3a,
3b, the setting information for the active devices 1a and 1b is transferred to the backup device 3 via the selector 6.
The backup devices 3a and 3b are added to the decoder 4 and encoder 5 of the active devices 1 and 3b.
It is possible to perform decoding and encoding in the same code format as a and 1b, and when the active devices 2a and 2b are switched and connected to the backup devices 3a and 3b, the active devices 2a and
The setting information for 2b is applied to the decoder 4 and encoder 5 of the standby devices 3a and 3b via the selector 6, and it is possible to perform decoding and encoding in the same code format as the active devices 2a and 2b.

〔Example〕

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

FIG. 2 is a block diagram of an embodiment of the present invention, in which 11 and 12 are active transmitters, 13 is a backup transmitter, and 14 is a decoder for decoding an AMI code into an NRZ code according to setting information a and b. Or BnZS code
Decoder for setting whether to decode to NRZ code, 15
1 is a signal processing section, 16 is a transmitting section that performs modulation processing such as multilevel QAM, 17 is a switching circuit, 18 and 19 are hybrid circuits, and 20 is a selector.

A bipolar signal A of the AMI code is applied to the current transmitting device 11 via the hybrid circuit 18,
Further, when the bipolar signal B of the BnZS code is applied to the current transmitting device 12 via the hybrid circuit 19, the decoder 14 of the current transmitting device 11 is set to decode the AMI code to the NRZ code according to the setting information a. The active transmitting device 12 according to the setting information b.
The decoder 14 is configured to decode the BnZS code into an NRZ code.

These setting information a and b are added to the selector 20 of the backup transmitter 13, and the switching signal at this time is
Since the switching circuit 17 is switched to the neutral position, the preliminary transmitter 13 is in a state in which neither the bipolar signals A nor B of the AMI code or the BnZS code are applied. Therefore, the selector 20 selects the setting information a,
The operation of the backup transmitting device 13 is not affected whether or not the selective output of b is performed.

The signal decoded into the NRZ code by the decoder 14 is applied as a unipolar signal to the signal processing unit 15, and the signal processing unit 15 performs processing such as serial-to-parallel conversion and adds the unipolar signal to the transmitting unit 16. , four-phase phase modulation and multi-level modulation in the transmitter 16
Modulation such as QAM is performed and then transmitted.

When a failure occurs in the active transmitter 11, a control unit (not shown) detects the failure and sends a switching signal to the switching circuit 17 and selector 20 to switch and connect the backup transmitter 13 instead of the active transmitter 11. Added. As a result, the switching circuit 17
is switched and connected to the hybrid circuit 18 side,
Bipolar signal A of AMI code is sent to backup transmitter 1
3, and the setting information a for the active transmitter 11 is sent to the backup transmitter 13 via the selector 20.
The decoder 14 is set to have the function of decoding the AMI code to the NRZ code. Therefore, the backup transmitting device 13 can perform a transmitting operation in place of the active transmitting device 11.

In addition, if a failure occurs in the active transmitter 12,
The switching circuit 17 is switched to the hybrid circuit 19 side by the switching signal, the bipolar signal B of the BnZS code is added to the backup transmitter 13, and the setting information b for the active transmitter 12 is sent to the backup transmitter 13 via the selector 20. The decoder 14 is set to the function of decoding the BnZS code to the NRZ code. Therefore, the backup transmitting device 13 can perform a transmitting operation in place of the active transmitting device 12.

In Figure 2, only the transmitting side of the wireless communication system is shown, but the receiving side can also be configured accordingly, and NRZ codes can be encoded into AMI codes or BnZS codes depending on the setting information. An encoder is provided in the active receiving device and the backup receiving device, and in the backup receiving device, the setting information selected by the selector in response to the switching connection is added to the encoder.

FIG. 3 is a block diagram of another embodiment of the present invention, showing a working/standby switching system in which a switching circuit 27 connects a standby transmitter 24 to the working transmitters 21 to 23. For example, AMI
Bipolar signal A of code A, bipolar signal B of B8ZS code (a code that converts a block of 8 consecutive “0” bits into a bipolar signal with a special pattern due to bipolar violation), and B6ZS code.
A bipolar signal C of a code (a code for converting a block of 6 consecutive "0" into a bipolar signal with a special pattern due to bipolar violation) is added to the current transmitting devices 21 to 23 via the switching circuit 27, respectively. According to the setting information a, the decoder 25 of the current transmitter 21 converts the AMI code into NRZ
The setting information b sets the decoder 25 of the current transmitting device 22 to decode the B8ZS code into an NRZ code, and the setting information c sets the decoder 25 of the current transmitting device 23 to decode the B8ZS code into an NRZ code.
Set to decode B6ZS code to NRZ code.

Furthermore, when other active transmitting devices are provided and the decoder is configured using configuration information to decode in accordance with other code formats, the selector 26 of the backup transmitting device 24 contains settings for those active transmitting devices. Information a to n are added, a selector 26 is controlled by a switching signal that controls the switching circuit 27, and setting information a to n is selectively output and added to the decoder 25. Therefore, even if a plurality of active transmitters that transmit and process bipolar signals A, B, C, . When the transmitting device is switched and connected to the backup transmitting device 24 by the switching circuit 20, the setting information a is selected by the selector 27.
~ n selections are made and the configuration information of the active transmitter is added to the decoder 25 of the backup transmitter,
It becomes possible to continue the transmission operation.

Like the embodiment shown in FIG. 2, the embodiment shown in FIG. 3 only shows the transmitting side of the wireless communication system, so the receiving side is also equipped with an encoder capable of encoding different code formats. It consists of:

FIG. 4 is a block diagram of a main part of an example of a decoder, and shows a decoder having a function of decoding the aforementioned AMI code, B8ZS code, and B6ZS code into an NRZ code. A bipolar signal is generated by a circuit (not shown) that generates a positive polarity pulse PP and a negative polarity pulse.
The signal is separated into MP and applied to a conversion circuit 31, where it is converted into a unipolar signal and output.

The switching circuit 34 includes three conversion circuits 31, 32,
It selectively outputs the outputs of 33 and is controlled by 2-bit setting information. For example, setting information of "00" causes the switching circuit 34 to be set to selectively output the output of the conversion circuit 31 and decode the AMI code into the NRZ code.

Also, the switching circuit 34 selectively outputs the output of the conversion circuit 32 according to the setting information of "01",
The B8ZS code bipolar signal is separated into a positive pulse PP and a negative pulse MP, which are converted into a serial unipolar signal by the conversion circuit 31, and further converted into a special pattern unipolar signal by the conversion circuit 32 into an 8-bit "0" continuous signal. Therefore, the B8ZS code is set to be decoded into the NRZ code.

In addition, the switching circuit 34 selectively outputs the output of the conversion circuit 33 according to the setting signal of "10".
The B6ZS code will be set to be decoded into the NRZ code.

Therefore, in the standby transmitter, the configuration information of each working transmitter may be selected by a selector and added to the switching circuit 34 in response to the switching signal, and the faulty working transmitter It is possible to perform decoding processing for the same code format as .

Note that the same applies to the encoder, and it is also possible to provide a decoding or encoding means compatible with a large number of code formats, and set the encoder using setting information. Also, it is easy to integrate the decoder or encoder into an integrated circuit, and if the decoder and encoder are integrated into the same circuit, the same setting information can be used to perform decoding and encoding corresponding to the desired code format. Encoding can be configured and applied to transmitting and receiving devices.

〔Effect of the invention〕

As explained above, the present invention provides a decoder 4 or an encoder 5 that can set decoding or encoding based on setting information corresponding to the code format in the current devices 1a, 1.
b, 2a, 2b and spare devices 3a, 3b,
A selector 6 is provided in the backup devices 3a, 3b, and switching circuits 7a, 7b switch the current device to the backup device 3.
a, 3b, the setting information of the active device is sent to the decoder 4 of the standby device via the selector 6.
Or, by adding it to the encoder 5, the signal in the encoded format that was being processed by the current device can be transferred to the backup device 3.
A and 3b can be processed continuously, and one backup device can perform switching between the current devices with different code formats, creating an economical system. There is an advantage that it can be done.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of one embodiment of the invention, Fig. 3 is a block diagram of another embodiment of the invention, and Fig. 4 is a schematic diagram of an example of a decoder. FIG. 1a, 1b, 2a, 2b are current devices, 3a, 3
b is a backup device, 4 is a decoder, 5 is an encoder, 6 is a selector, 7a, 7b are switching circuits, 8 is a hybrid circuit, 11, 12, 21 to 23 are active transmitters, 13, 24 are backup transmitters , 14 and 25 are decoders, 15 is a signal processing section, 16 is a transmission section, 17 is a switching circuit, 18 and 19 are hybrid circuits, 2
0 and 26 are selectors, and 27 is a switching circuit.

Claims (1)

[Claims] 1. A decoder 4 that decodes or encodes the code format set by the setting information in the active devices 1a, 1b, 2a, 2b and the backup devices 3a, 3b, respectively.
Alternatively, an encoder 5 is provided, and the backup devices 3a and 3b are provided with a selector 6 for selecting different setting information and applied to the decoder 4 or the encoder 5, and switching circuits 7a and 7b switch the current device to the backup device 3a. , 3b, the setting information of the active device is added to the decoder 4 or encoder 5 of the backup device 3a, 3b via the selector 6,
A working-standby switching system characterized in that the standby devices 3a and 3b process signals in the code format that were being processed by the working device.