JP2010288067A - Radio system, transmitting device, receiving method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To guarantee the quality of reception without adding a system even when at least one system is brought to a defective transmission state, and to avoid the interruption state of a receiving signal of the whole radio system. <P>SOLUTION: Each of radio systems consists of a combination of a transmitting device and a receiving device, and includes two systems using mutually different frequencies and for transmitting transmission signals by radio, transmission-mode switches and receiving-mode switches. When either system of the two systems is brought to the defective transmission state previously, the receiving device of one system changes the frequency into the frequency of other system. The transmission-mode switches output the transmission signals only to the transmitting device of the other system, and the receiving-mode switches output the transmission signals with a higher receiving-quality level out of the transmission signals received by using the frequency of the other system by each receiving device of the two systems. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless system, a transmission device, a reception method, and a program.

  In recent years, the speed of Ethernet (registered trademark) has been increasing. Accordingly, there is an increasing need for speeding up wireless transmission even in a wireless system that wirelessly transmits an Ethernet signal transmitted by Ethernet.

  One method for speeding up wireless transmission is to use a technique called link aggregation defined in IEEE (Institute of Electrical and Electronics Engineers) 802.3ad. Link aggregation is a technology that bundles a plurality of lines and handles them virtually as one line.

  Hereinafter, a radio system using link aggregation technology will be described with reference to FIG. 9 (see, for example, Patent Document 1). Here, there are provided two systems (# 1, # 2) each consisting of a transmitter and a receiver and transmitting Ethernet signals wirelessly using different frequencies (f1, f2). A wireless system will be described.

  The wireless system illustrated in FIG. 9 includes transmission apparatuses 100A and 100B that wirelessly transmit Ethernet signals.

  The transmission apparatus 100A includes transmitters (# 1, # 2) 121-1 and 121-2, and a link aggregation (TX: Transmit) circuit 122.

  The transmission apparatus 100B includes receivers (# 1, # 2) 131-1 and 131-2, and a link aggregation (RX) circuit 132.

  In FIG. 9, only the configuration on the transmission side is shown for the transmission device 100A, and only the configuration on the reception side is shown for the transmission device 100B.

  In addition, it is assumed that the individual transmission capacities of the transmitters (# 1, # 2) 121-1 and 121-2 and the receivers (# 1, # 2) 131-1 and 131-2 are 150 Mbps.

  In the transmission device 100A, the link aggregation (TX) circuit 122 sequentially transmits the Ethernet signal (packet) input to the input terminal to the transmitter (# 1) 121-1 and the transmitter (# 2) 121-2. Distribute and output.

  The transmitter (# 1) 121-1 transmits the Ethernet signal distributed to itself to the receiver (# 1) 131-1 wirelessly using the frequency f1. Further, the transmitter (# 2) 121-2 transmits the Ethernet signal distributed to itself to the receiver (# 2) 131-2 wirelessly using the frequency f2.

  On the other hand, in the transmission apparatus 100B, the receiver (# 1) 131-1 receives and outputs the Ethernet signal transmitted wirelessly from the transmitter (# 1) 121-1A-1 using the frequency f1. . Further, the receiver (# 2) 131-2 receives and outputs the Ethernet signal transmitted by radio from the transmitter (# 2) 121-2 using the frequency f2.

  The link aggregation (RX) circuit 132 accumulates the Ethernet signals output from the receivers (# 1, # 2) 131-1 and 131-2, restores the original Ethernet signals, and outputs them from the output terminal.

  Therefore, in the wireless system shown in FIG. 9, throughput transmission corresponding to a transmission capacity (300 Mbps) that is twice the individual transmission capacity (150 Mbps) of the transmitters (# 1, # 2) 121-1 and 121-2. Can be realized.

JP 2005-260904 A

  However, the wireless system shown in FIG. 9 has the following problems.

  As shown in FIG. 10, it is assumed that both systems (# 1, # 2) have a transmission failure. Here, the transmission failure means that the reception signal level is lower than the threshold value, and the reception signal is in a state where the reception signal cannot be received. In this case, the entire radio system is in a reception signal disconnection state.

  In addition, when one of the systems (# 1, # 2) has a transmission failure, wireless transmission is continued only with the other system, and there is a concern that the reception quality may deteriorate.

  Therefore, there is a problem that another system must be added in order to guarantee the reception quality and to prevent the entire wireless system from being in a reception signal disconnection state.

  Therefore, an object of the present invention is to solve the above-mentioned problems, guarantee the reception quality without adding a system even when at least one of the systems becomes defective in transmission, and the entire radio system is in a reception signal disconnected state. It is an object of the present invention to provide a wireless system, a transmission device, a reception method, and a program that can avoid this.

The wireless system of the present invention includes:
Two systems each consisting of a transmitter and receiver pair, using different frequencies to transmit the transmission signal wirelessly;
When both of the two systems are normal, a transition to the first transmission mode, a transmission mode switch for distributing and outputting the transmission signal to the respective transmitters of the two systems,
When both of the two systems are normal, a reception mode switch for shifting to the first reception mode and accumulating and outputting transmission signals received by the respective receivers of the two systems is provided. And
If one of the two systems fails first,
The receiver of the one system is
Change the frequency to the frequency of the other system,
The transmission mode switch is
Transition to the second transmission mode, output the transmission signal only to the transmitter of the other system,
The reception mode switch is
Transition to the second reception mode, and output a transmission signal having a higher reception quality level among transmission signals received using the frequency of the other system at the receiver of each of the two systems. .

The transmission apparatus of the present invention
Two receivers respectively belonging to the two systems and using different frequencies to receive transmission signals wirelessly;
When both of the two systems are normal, a reception mode switch for shifting to the first reception mode and accumulating and outputting transmission signals received by the respective receivers of the two systems is provided. And
If one of the two systems fails first,
The receiver of the one system is
Change the frequency to the frequency of the other system,
The reception mode switch is
Transition to the second reception mode, and output a transmission signal having a higher reception quality level among transmission signals received using the frequency of the other system at the receiver of each of the two systems. .

The receiving method of the present invention includes:
When both the two systems that belong to the two systems and receive the transmission signal wirelessly using different frequencies and the two systems are normal, transition to the first reception mode, A reception mode switch for receiving and switching transmission signals received by receivers of each of the two systems;
If one of the two systems fails first,
The receiver of said one system changes the frequency to the frequency of the other system;
The reception mode switch transits to the second reception mode, and a reception quality level is high among transmission signals received using the frequency of the other system at the receiver of each of the two systems. Outputting the transmission signal of the other side.

The program of the present invention
When both the two systems that belong to the two systems and receive the transmission signal wirelessly using different frequencies and the two systems are normal, transition to the first reception mode, A transmission apparatus comprising: a reception mode switch that accumulates and outputs transmission signals received by receivers of each of the two systems;
If one of the two systems fails first,
A procedure in which the receiver of the one system changes the frequency to the frequency of the other system;
The reception mode switch transits to the second reception mode, and a reception quality level is high among transmission signals received using the frequency of the other system at the receiver of each of the two systems. And a procedure for outputting the other transmission signal.

  According to the present invention, when both of the two systems are normal, the transmission side distributes and outputs the transmission signal to the two transmitters, and the reception side outputs the transmission signals output from the two receivers. Stack and output.

  Therefore, it is possible to achieve the throughput transmission corresponding to the transmission capacity twice the individual transmission capacity of the transmitter.

  If one system fails first, the transmitting side outputs the transmission signal only to the transmitter of the other system, and the receiving side sets the frequency of the receiver of one system to that of the other system. The frequency is changed, and the transmission signal having the higher reception quality level among the transmission signals received using the frequency of the other system at each of the two receivers is output.

  Therefore, the reception quality is improved because it is the same as operating the wireless system in the space diversity (SD) mode.

  Therefore, even when at least one of the two systems has a transmission failure, the reception quality can be guaranteed without adding a system, so that the entire wireless system can be prevented from being in a reception signal disconnection state. The effect that it can be obtained.

It is a block diagram which shows an example of a structure of the radio | wireless system of one Embodiment of this invention. It is a block diagram which shows an example of a structure of the transmission mode switch shown in FIG. It is a figure explaining an example of the operation | movement at the time of link aggregation (TX) mode in the transmission mode switch shown in FIG. 2A. It is a figure explaining an example of operation | movement at the time of a system (# 1) fixed mode in the transmission mode switch shown in FIG. 2A. It is a figure explaining an example of operation | movement at the time of a system (# 2) fixed mode in the transmission mode switch shown in FIG. 2A. It is a block diagram which shows an example of a structure of the reception mode switch shown in FIG. It is a figure explaining an example of the operation | movement at the time of link aggregation (RX) mode in the reception mode switch shown to FIG. 2A. It is a figure explaining an example of the operation | movement at the time of hitless switching mode in the receiving mode switch shown to FIG. 2A. It is a figure explaining the other example of operation | movement at the time of hitless switching mode in the receiving mode switch shown to FIG. 2A. It is a figure explaining an example of an operation | movement when both of systems (# 1, # 2) are normal in the radio | wireless system shown in FIG. It is a figure explaining an example of operation | movement when the system (# 2) becomes a transmission failure first in the radio | wireless system shown in FIG. It is a figure explaining an example of operation | movement when the system (# 1) becomes a transmission failure first in the radio | wireless system shown in FIG. It is a figure explaining an example of the operation | movement in the case of returning from SD mode in the radio | wireless system shown in FIG. It is a figure explaining an example of the transmission condition of the radio | wireless system shown in FIG. It is a block diagram which shows an example of a structure of a related radio | wireless system. FIG. 10 is a diagram illustrating an example of a transmission status of the wireless system illustrated in FIG. 9.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to drawings.

  In the following embodiments, two systems (# 1, # 2) each consisting of a pair of a transmitter and a receiver and transmitting Ethernet signals wirelessly using different frequencies (f1, f2). An example in which the present invention is applied to a wireless system provided with the above system will be described.

(1) Configuration of Radio System (1-1) Overall Configuration of Radio System First, the overall configuration of the radio system according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the wireless system according to the present embodiment includes transmission apparatuses 10A and 10B that wirelessly transmit Ethernet signals that are transmission signals.

  The transmission apparatus 10A includes transmitters (# 1, # 2) 21-1A and 21-2A, and a transmission mode switch 22A.

  The transmission apparatus 10B includes receivers (# 1, # 2) 31-1B and 31-2B, and a reception mode switch 32B.

  In FIG. 1, only the configuration on the transmission side is shown for the transmission device 10A, and only the configuration on the reception side is shown for the transmission device 10B. However, as will be described later, the reception of the transmission device 10A is shown. It is assumed that the same component as the reception side of the transmission device 10B is provided on the side, and the same component as the transmission side of the transmission device 10A is provided on the transmission side of the transmission device 10B.

  In addition, it is assumed that the individual transmission capacities of the transmitters (# 1, # 2) 21-1A, 21-2A and the receivers (# 1, # 2) 31-1B, 31-2B are 150 Mbps.

  Further, the transmitter (# 1) 21-1A and the receiver (# 1) 31-1B perform radio transmission using the frequency f1, and the transmitter (# 2) 21-2A and the receiver (# 2) 31-2B performs radio transmission using the frequency f2.

  However, in this embodiment, the receivers (# 1, # 2) 31-1B and 31-2B can change the frequency according to the state of transmission failure of the system (# 1, # 2).

  Further, the transmission mode switch 22A switches the transmission mode and the reception mode switch 32B switches the reception mode according to the transmission failure status of the system (# 1, # 2).

  In addition, as a method for determining whether or not the system (# 1, # 2) has a transmission failure, there is a method for determining using a transmission state or a device failure state.

  As a method of using the transmission status, for example, according to RSL (Received Signal Level), BER (Bit Error Rate), or waveform distortion amount of a radio signal received by the receiver There is a method of defining a reception quality level and determining a transmission failure when the reception quality level is equal to or lower than a threshold value. In this case, the transmission failure can be determined by the receiver. Note that the RSL and BER measurement methods and the waveform distortion amount calculation method are not particularly limited, and known methods can be used.

  In addition, as a method of using the failure status of a device, for example, there is a method of determining a transmission failure when a device constituting the system reports an alarm due to a failure. In this case, transmission failure can be determined by detecting an alarm in each device other than the failed device.

  In this embodiment, the following transmission modes (A) to (C) are available.

(A) Link aggregation (TX) mode (first transmission mode)
The transmission mode switch 22A transitions to this mode when both systems (# 1, # 2) are normal (the situation where no transmission failure has occurred; the same applies hereinafter).

  In this mode, the transmission mode switch 22A connects the input terminal to both the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A, and the Ethernet signal (packet) input to the input terminal. Are sequentially distributed to the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A and output.

(B) System (# 1) fixed mode (second transmission mode)
The transmission mode switch 22A is used when the system (# 2) has a transmission failure before the system (# 1) (when only the system (# 2) has a transmission failure and the system (# 2) Next, the system (# 1) also includes a case where the transmission failure occurs (the same applies hereinafter), and transitions to this mode.

  In this mode, the transmission mode switch 22A connects the input terminal only to the transmitter (# 1) 21-1A, and transmits the Ethernet signal (packet) input to the input terminal to the transmitter (# 1) 21-1A. To output.

(C) System (# 2) fixed mode (second transmission mode)
The transmission mode switch 22A is used when the system (# 1) has a transmission failure before the system (# 2) (when only the system (# 1) has a transmission failure and when the system (# 1) Next, the system (# 2) also includes a case where the transmission is defective.

  In this mode, the transmission mode switch 22A connects the input terminal only to the transmitter (# 2) 21-2A, and transmits the Ethernet signal (packet) input to the input terminal to the transmitter (# 2) 21-2A. To output.

  On the other hand, the following reception modes (a) and (b) are available.

(A) Link aggregation (RX) mode (first reception mode)
The reception mode switch 32B transitions to this mode when both the systems (# 1, # 2) are normal.

  In this mode, the reception mode switch 32B connects the output terminals to both the receiver (# 1) 31-1B and the receiver (# 2) 31-2B, and the receiver (# 1, # 2) 31- The Ethernet signals output from 1B and 31-2B are stacked, restored to the original Ethernet signal, and output from the output terminal.

  Therefore, in this mode, it is possible to realize throughput transmission corresponding to a transmission capacity (300 Mbps) that is twice the individual transmission capacity (150 Mbps) of the transmitters (# 1, # 2) 21-1A and 21-2A. .

(B) Hitless switching mode (second reception mode)
The reception mode switch 32B transits to this mode when at least one of the systems (# 1, # 2) has a transmission failure. In this case, the receiver of the system (# 1, # 2) having the transmission failure first changes the frequency to the frequency of the other system.

  In this mode, for example, when the system (# 2) has a transmission failure first, the reception mode switch 32B uses the receiver (# 1) 31-1B and the receiver (# 2) 31-2B as output terminals. Connect to both.

  At this time, both the receivers (# 1, # 2) 31-1B and 31-2B receive the Ethernet signal transmitted by radio from the transmitter (# 1) 21-1A using the frequency f1. is doing.

  Therefore, the reception mode switch 32B receives the signal having the higher reception quality level (RSL, BER, or a level corresponding to the amount of waveform distortion) among the receivers (# 1, # 2) 31-1B, 31-2B. Select the Ethernet signal output from the machine and output it from the output terminal.

  On the other hand, when the system (# 1) has a transmission failure first, the reception mode switch 32B connects the output terminal to both the receiver (# 1) 31-1B and the receiver (# 2) 31-2B. To do.

  At this time, both the receivers (# 1, # 2) 31-1B and 31-2B receive the Ethernet signal transmitted by radio from the transmitter (# 2) 21-2A using the frequency f2. is doing.

  Therefore, the reception mode switch 32B selects the Ethernet signal output from the receiver having the higher reception quality level among the receivers (# 1, # 2) 31-1B and 31-2B, and outputs an output terminal. Output from.

  Therefore, this mode is the same as operating the wireless system in the space diversity (SD) mode, so that the reception quality is improved.

  Therefore, even when at least one of the systems becomes defective in transmission, it is possible to guarantee the reception quality without adding a system, so that it is possible to avoid the entire radio system from being in a reception signal disconnection state.

(1-2) Configuration of Transmission Mode Switcher 22A Next, the configuration of the transmission mode switcher 22A will be described with reference to FIGS. 2A to 2D.

  As shown in FIG. 2A, the transmission mode switch 22A has a link aggregation (TX) circuit (indicated as “Link AGR (TX)” in the figure) 23A.

  As shown in FIG. 2B, in the link aggregation (TX) mode of the above (A), the link aggregation (TX) circuit 23A uses the transmitter (# 1) 21-1A and the transmitter (# 2) 21- as input terminals. 2A, the Ethernet signal (packet) input to the input terminal is sequentially distributed to the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A and output. .

  As shown in FIG. 2C, in the system (# 1) fixed mode of (B) above, the link aggregation (TX) circuit 23A connects the input terminal only to the transmitter (# 1) 21-1A and connects to the input terminal. The input Ethernet signal (packet) is output to the transmitter (# 1) 21-1A.

  As shown in FIG. 2D, in the system (# 2) fixed mode of (C) above, the link aggregation (TX) circuit 23A connects the input terminal only to the transmitter (# 2) 21-2A and connects to the input terminal. The input Ethernet signal (packet) is output to the transmitter (# 2) 21-2A.

(1-3) Configuration of Reception Mode Switcher 32B Next, the configuration of the reception mode switcher 32B will be described with reference to FIGS. 3A to 3D.

  As shown in FIG. 3A, the reception mode switch 32B includes a hitless switch (indicated as “HL SW” in the figure) (# 1, # 2) 33-1B, 33-2B, and a link aggregation (RX) circuit. (Denoted as “Link AGR (RX)” in the figure) 34B.

  As shown in FIG. 3B, in the link aggregation (RX) mode of (a), the link aggregation (RX) circuit 34B uses the hitless switch (# 1) 33-1B and the hitless switch (# 2) Connect to both 33-2B, accumulate Ethernet signals output from the receivers (# 1, # 2) 31-1B, 31-2B, restore the original Ethernet signals, and output from the output terminal.

  As shown in FIG. 3C, in the hitless switching mode of (b) above, when the system (# 2) has a transmission failure first, the link aggregation (RX) circuit 34B makes the output terminal hitless. Only the switch (# 1) 33-1B is connected, and the hitless switch (# 1) 33-1B is connected to both the receiver (# 1) 31-1B and the receiver (# 2) 31-2B. To do. The hitless switch (# 1) 33-1B receives the Ethernet signal output from the receiver having the higher reception quality level among the receivers (# 1, # 2) 31-1B and 31-2B. Then, the link aggregation (RX) circuit 34B outputs the Ethernet signal selected by the hitless switch (# 1) 33-1B from the output terminal.

  As shown in FIG. 3D, in the hitless switching mode of (b) above, when the system (# 1) has a transmission failure first, the link aggregation (RX) circuit 34B sets the output terminal to be hitless. Connect to switch (# 2) 33-2B only, hitless switch (# 2) 33-2B connects to both receiver (# 1) 31-1B and receiver (# 2) 31-2B To do. The hitless switch (# 2) 33-2B receives the Ethernet signal output from the receiver having the higher reception quality level among the receivers (# 1, # 2) 31-1B and 31-2B. Then, the link aggregation (RX) circuit 34B outputs the Ethernet signal selected by the hitless switch (# 2) 33-2B from the output terminal.

(2) Operation of Radio System Hereinafter, the operation of the radio system according to the present embodiment will be described with reference to FIGS.

  4 to 7 also illustrate components on the reception side of the transmission apparatus 10A and the transmission side of the transmission apparatus 10B, which are not illustrated in FIG.

  Specifically, the receiver (# 1 ′, # 2 ′) 31-1′A, 31-2′A and the hitless are set on the reception side of the transmission device 10A, as with the reception side of the transmission device 10B. A receiving mode switching unit 32A including switching units (# 1 ′, # 2 ′) 33-1′A, 33-2′A and a link aggregation (RX) circuit 34A is provided.

  Further, on the transmission side of the transmission apparatus 10B, similarly to the transmission side of the transmission apparatus 10A, transmitters (# 1 ′, # 2 ′) 21-1′B, 21-2′B and link aggregation (TX) And a transmission mode switch 22B including a circuit 23B.

(2-1) Operation when both systems (# 1, # 2) are normal First, the operation when both systems (# 1, # 2) are normal will be described with reference to FIG. To do.

  In this case, in the transmission apparatus 10A, the transmission mode switch 22A transits to the link aggregation (TX) mode of (A).

  That is, the link aggregation (TX) circuit 23A connects the input terminal to both the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A (step S11), and the Ethernet input to the input terminal The signals (packets) are sequentially distributed to the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A and output (step S12).

  On the other hand, in the transmission apparatus 10B, the frequency of the receiver (# 1) 31-1B remains f1, and the frequency of the receiver (# 2) 31-2B remains f2 (step S13).

  Further, the reception mode switch 32B transitions to the link aggregation (RX) mode of (a).

  That is, the link aggregation (RX) circuit 34B connects the output terminals to both the hitless switch (# 1) 33-1B and the hitless switch (# 2) 33-2B (step S14), and the receiver ( # 1, # 2) The Ethernet signals output from 31-1B and 31-2B are stacked to restore the original Ethernet signal, and output from the output terminal (step S15).

(2-2) Operation when system (# 2) first fails in transmission Next, operation when system (# 2) first fails in transmission will be described with reference to FIG. . Here, description will be made assuming that receiver (# 2) 31-2B detects a transmission failure based on the transmission status of system (# 2).

  When the system (# 2) has a transmission failure first (step S21), the receiver (# 2) 31-2B detects this and switches the frequency from f2 to f1 (step S22).

  In addition, the reception mode switch 32B transitions to the hitless switching mode (b).

  That is, the link aggregation (RX) circuit 34B connects the output terminal only to the hitless switch (# 1) 33-1B, and the hitless switch (# 1) 33-1B receives the receiver (# 1) 31. -1B and the receiver (# 2) 31-2B are connected (step S23). Further, the link aggregation (RX) circuit 34B instructs the receiver (# 1) 31-1B to continue the frequency at f1 even if a transmission failure of the system (# 1) is detected.

  Further, the link aggregation (RX) circuit 34B converts information indicating that the transmission failure of the system (# 2) into a DSC (Digital Service Channel) signal, and transmits the transmitter (# 1 ′) 21 via the DSC. -1′B (step S24).

  Then, the transmitter (# 1 ′) 21-1′B wirelessly transmits the DSC signal to the receiver (# 1 ′) 31-1′A of the transmission apparatus 10A using the frequency f1 ′ ( In step S25), the receiver (# 1 ′) 31-1′A transfers the DSC signal to the transmission mode switch 22A via the DSC (step S26).

  The transmission mode switch 22A receives the DSC signal and transitions to the system (# 1) fixed mode of (B).

  That is, the link aggregation (TX) circuit 23A connects the input terminal only to the transmitter (# 1) 21-1A (step S27), and transmits the Ethernet signal (packet) input to the input terminal to the transmitter (# 1). ) Output to 21-1A (step S28).

  Thereafter, the hitless switch (# 1) 33-1B receives the Ethernet signal output from the receiver having the higher reception quality level among the receivers (# 1, # 2) 31-1B and 31-2B. Then, the link aggregation (RX) circuit 34B outputs the Ethernet signal selected by the hitless switch (# 1) 33-1B from the output terminal (step S29).

  Therefore, the wireless system shifts to the SD mode. This state is used to return to the normal mode (both the transmission side and the reception side are the link aggregation mode, hereinafter the same), which will be described later, regardless of whether or not the system (# 1) has a transmission failure. Continue until the condition is met.

(2-3) Operation when system (# 1) first fails in transmission Next, operation when system (# 1) first fails in transmission will be described with reference to FIG. . Here, it is assumed that the receiver (# 1) 31-1B detects a transmission failure based on the transmission status of the system (# 1).

  When the system (# 1) has a transmission failure first (step S31), the receiver (# 1) 31-1B detects this and switches the frequency from f1 to f2 (step S32).

  In addition, the reception mode switch 32B transitions to the hitless switching mode (b).

  That is, the link aggregation (RX) circuit 34B connects the output terminal only to the hitless switch (# 2) 33-2B, and the hitless switch (# 2) 33-2B receives the receiver (# 1) 31. -1B and the receiver (# 2) 31-2B are connected (step S33). Further, the link aggregation (RX) circuit 34B instructs the receiver (# 2) 31-2B to continue the frequency at f2 even if a transmission failure of the system (# 2) is detected.

  Further, the link aggregation (RX) circuit 34B converts information indicating that the system (# 1) has a transmission failure into a DSC signal, and sends it to the transmitter (# 2 ′) 21-2′B via the DSC. Transfer (step S34).

  Then, the transmitter (# 2 ′) 21-2′B wirelessly transmits the DSC signal to the receiver (# 2 ′) 31-2′A of the transmission apparatus 10A using the frequency f2 ′ ( In step S35, the receiver (# 2 ′) 31-2′A transfers the DSC signal to the transmission mode switch 22A via the DSC (step S36).

  The transmission mode switch 22A receives the DSC signal and transitions to the system (# 2) fixed mode of (B).

  That is, the link aggregation (TX) circuit 23A connects the input terminal only to the transmitter (# 2) 21-2A (step S37), and transmits the Ethernet signal (packet) input to the input terminal to the transmitter (# 2 ) Output to 21-2A (step S38).

  Thereafter, the hitless switch (# 2) 33-2B receives the Ethernet signal output from the receiver having the higher reception quality level among the receivers (# 1, # 2) 31-1B and 31-2B. Then, the link aggregation (RX) circuit 34B outputs the Ethernet signal selected by the hitless switch (# 2) 33-2B from the output terminal (step S39).

  Therefore, the wireless system operates in the SD mode. This state is continued until a condition for returning to the normal mode, which will be described later, is satisfied, regardless of whether or not the system (# 2) becomes defective in transmission.

(2-4) Operation for Returning from SD Mode Next, the operation for returning from the SD mode will be described with reference to FIG. Here, the operation in the case of returning from the SD mode (lower part in FIG. 5) that has been shifted to the trigger of the detection of the transmission failure based on the transmission status of the system (# 2) in the above (2-2) will be described.

  When both the systems (# 1, # 2) are in a normal state for a certain time (for example, 5 minutes) (step S41), the link aggregation (RX) circuit 34B is connected to the receiver (# 1) 31-1B and This is detected via the receiver (# 2) 31-2B. Then, the link aggregation (RX) circuit 34B releases the instruction to continue the frequency f1 to the receiver (# 1) 31-1B, and the frequency is changed from f1 to the receiver (# 2) 31-2B. An instruction is given to return to f2 (step S42).

  Further, the reception mode switch 32B returns to the link aggregation (RX) mode of (a).

  That is, the link aggregation (RX) circuit 34B connects the output terminals to both the hitless switch (# 1) 33-1B and the hitless switch (# 2) 33-2B (step S43).

  Further, the link aggregation (RX) circuit 34B converts information indicating that both of the systems (# 1, # 2) are in a normal state into a DSC signal, and transmits the transmitter (# 1 ′) via the DSC. Transfer to 21-1′B (step S44).

  Then, the transmitter (# 1 ′) 21-1′B wirelessly transmits the DSC signal to the receiver (# 1 ′) 31-1′A of the transmission apparatus 10A using the frequency f1 ′ ( In step S45), the receiver (# 1 ′) 31-1′A transfers the DSC signal to the transmission mode switch 22A via the DSC (step S46).

  The transmission mode switch 22A receives the DSC signal and returns to the link aggregation (TX) mode of (A).

  That is, the link aggregation (TX) circuit 23A connects the input terminal to both the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A (step S47), and the Ethernet input to the input terminal The signal (packet) is sequentially distributed to the transmitter (# 1) 21-1A and the transmitter (# 2) 21-2A and outputted (step S48).

  Thereafter, the link aggregation (RX) circuit 34B accumulates the Ethernet signals output from the receivers (# 1, # 2) 31-1B and 31-2B, restores the original Ethernet signals, and outputs them from the output terminal ( Step S49).

  Therefore, the wireless system shifts to the normal mode.

  Note that the operation for returning from the SD mode (2-3) (lower part of FIG. 6) is substantially the same, and thus the description thereof is omitted.

  As described above, in the present embodiment, when both the systems (# 1, # 2) are normal, the transmission side of the communication device 10A transmits Ethernet signals to the transmitter (# 1) 21-1A and the transmitter (# 2) The data is distributed and output to 21-2A, and the Ethernet signals output from the receivers (# 1, # 2) 31-1B, 31-2B are stacked and output on the reception side of the communication device 10B.

  Therefore, in this case, as shown in FIG. 8, the throughput corresponding to the transmission capacity (300 Mbps) twice the individual transmission capacity (150 Mbps) of the transmitters (# 1, # 2) 21-1A and 21-2A. Transmission can be realized.

  On the other hand, when at least one of the systems (# 1, # 2) has a transmission failure, for example, if the system (# 2) has a transmission failure first, the transmission side of the communication device 10A transmits an Ethernet signal. Only on the receiver (# 1) 21-1A, and on the receiving side of the communication device 10B, the frequency of the receiver (# 1) is changed from f1 to f2, and the receiver (# 1, # 2) 31-1B, The Ethernet signal output from the higher reception quality level of 31-2B is selected and output.

  Therefore, in this case, as shown in FIG. 8, since the radio system is the same as operating in the SD mode, the reception quality is improved.

  Therefore, even when at least one of the systems (# 1, # 2) has a transmission failure, the reception quality can be guaranteed without adding a system, so the entire wireless system is in a reception signal disconnected state. Can be avoided.

  In the present embodiment, the condition for returning from the SD mode is that both systems (# 1, # 2) are in a normal state for a certain period of time, but the present invention is not limited to this.

  For example, when the mode is shifted to the SD mode when the waveform distortion amount is equal to or less than the threshold value (that is, transmission failure occurs), the SD mode is subsequently set on condition that the waveform distortion amount exceeds the threshold value. It is good also as returning from.

  In this case, if the system (# 2) has a transmission failure first, the receiver (# 2) 31-2B temporarily changes the frequency to f2 after a certain period of time has elapsed after changing the frequency to f1. The waveform distortion amount is recalculated and the waveform distortion amount is recalculated. If the recalculated waveform distortion amount exceeds the threshold, it is sufficient to return from the SD mode. If the recalculated waveform distortion amount is still less than or equal to the threshold, receiver (# 2) 31-2B keeps the frequency at f1 and continues the SD mode.

  In the present embodiment, the transmitter (# 1) 21-1A, the transmitter (# 2) 21-2A, and the transmission mode switch 22A are described as being provided in the same transmission apparatus 10A. The present invention is not limited to this, and may be provided in a separate and independent device.

  Similarly, the receiver (# 1) 31-1B, the receiver (# 2) 31-2B, and the reception mode switch 32B have been described as being provided in the same transmission device 10B. However, the present invention is not limited to this, and may be provided in a separate and independent device.

  Moreover, although this embodiment demonstrated as what has two systems (# 1, # 2), this invention is not limited to this, The number of systems should just be two or more.

  In this case, as the frequency in the SD mode, an arbitrary frequency may be selected from the frequencies of systems other than the system in which transmission is defective. As a method of selecting a frequency in this case, a method of determining the priority of each system in advance and selecting the frequency of the system with the highest priority from the systems other than the system having the transmission failure may be considered.

  Further, the method performed by the transmission apparatuses 10A and 10B of the present invention may be applied to a program for causing a computer to execute. In addition, the program can be stored in a storage medium and can be provided to the outside via a network.

10A, 10B Transmission devices 21-1A, 21-2A, 21-1′B, 21-2′B Transmitters 22A, 22B Transmission mode changers 23A, 23B Link aggregation (TX) circuits 31-1B, 31-2B, 31-1′A, 31-2′A Receiver 32B, 32A Reception mode switcher 33-1B, 33-2B, 33-1′A, 33-2′A Hitless switcher 34B, 34A Link aggregation (RX )circuit

Claims (15)

Two systems each consisting of a transmitter and receiver pair, using different frequencies to transmit the transmission signal wirelessly;
When both of the two systems are normal, a transition to the first transmission mode, a transmission mode switch for distributing and outputting the transmission signal to the respective transmitters of the two systems,
When both of the two systems are normal, a reception mode switch for shifting to the first reception mode and accumulating and outputting transmission signals received by the respective receivers of the two systems is provided. And
If one of the two systems fails first,
The receiver of the one system is
Change the frequency to the frequency of the other system,
The transmission mode switch is
Transition to the second transmission mode, output the transmission signal only to the transmitter of the other system,
The reception mode switch is
Transition to the second reception mode, and output a transmission signal having a higher reception quality level among transmission signals received using the frequency of the other system at the receiver of each of the two systems. , Wireless system. After the one system becomes defective in transmission, until the predetermined condition is satisfied regardless of whether the other system becomes defective in transmission,
The receiver of the one system is
Leave the frequency as the frequency of the other system,
The transmission mode switch is
Leave in the second transmission mode,
The reception mode switch is
The wireless system according to claim 1, wherein the second reception mode is maintained. The predetermined condition is that a state in which both of the two systems are normal continues for a certain period of time,
When the predetermined condition is satisfied,
The receiver of the one system is
Return the frequency to the frequency of the one system,
The transmission mode switch is
Returning to the first transmission mode,
The reception mode switch is
The wireless system according to claim 2, wherein the wireless system returns to the first reception mode. The transmission failure is that the amount of waveform distortion calculated for the transmission signal received by the receiver is less than or equal to a threshold by the receiver.
The predetermined condition is that the amount of waveform distortion recalculated by temporarily returning the frequency to the frequency of the one system by the receiver of the one system exceeds a threshold value,
When the predetermined condition is satisfied,
The receiver of the one system is
Return the frequency to the frequency of the one system,
The transmission mode switch is
Returning to the first transmission mode,
The reception mode switch is
The wireless system according to claim 2, wherein the wireless system returns to the first reception mode. The reception mode switch is
Two hitless switches provided corresponding to each of the two systems;
A link aggregation circuit, and
In the first reception mode,
Each of the two hitless switches is
Connect to the receiver of the corresponding system, output the transmission signal received by the connected receiver,
The link aggregation circuit is
Connected to the two hitless switchers, stacked and output the transmission signals output from each of the two hitless switchers connected,
In the second reception mode,
The hitless switch corresponding to the other system is
Connected to the receivers of the two systems, and outputs a transmission signal having a higher reception quality level among transmission signals received by the receivers of the two connected systems,
The link aggregation circuit is
The wireless system according to claim 1, wherein the wireless system is connected to a hitless switch corresponding to the other system and outputs a transmission signal output from the connected hitless switch. Two receivers respectively belonging to the two systems and using different frequencies to receive transmission signals wirelessly;
When both of the two systems are normal, a reception mode switch for shifting to the first reception mode and accumulating and outputting transmission signals received by the respective receivers of the two systems is provided. And
If one of the two systems fails first,
The receiver of the one system is
Change the frequency to the frequency of the other system,
The reception mode switch is
Transition to the second reception mode, and output a transmission signal having a higher reception quality level among transmission signals received using the frequency of the other system at the receiver of each of the two systems. , Transmission equipment. After the one system becomes defective in transmission, until the predetermined condition is satisfied regardless of whether the other system becomes defective in transmission,
The receiver of the one system is
Leave the frequency as the frequency of the other system,
The reception mode switch is
The transmission apparatus according to claim 6, wherein the second reception mode is maintained. The predetermined condition is that a state in which both of the two systems are normal continues for a certain period of time,
When the predetermined condition is satisfied,
The receiver of the one system is
Return the frequency to the frequency of the one system,
The reception mode switch is
The transmission apparatus according to claim 7, wherein the transmission apparatus returns to the first reception mode. The transmission failure is that the amount of waveform distortion calculated for the transmission signal received by the receiver is less than or equal to a threshold by the receiver.
The predetermined condition is that the amount of waveform distortion recalculated by temporarily returning the frequency to the frequency of the one system by the receiver of the one system exceeds a threshold value,
When the predetermined condition is satisfied,
The receiver of the one system is
Return the frequency to the frequency of the one system,
The reception mode switch is
The transmission apparatus according to claim 7, wherein the transmission apparatus returns to the first reception mode. The reception mode switch is
Two hitless switches provided corresponding to each of the two systems;
A link aggregation circuit, and
In the first reception mode,
Each of the two hitless switches is
Connect to the receiver of the corresponding system, output the transmission signal received by the connected receiver,
The link aggregation circuit is
Connected to the two hitless switchers, stacked and output the transmission signals output from each of the two hitless switchers connected,
In the second reception mode,
The hitless switch corresponding to the other system is
Connected to the receivers of the two systems, and outputs a transmission signal having a higher reception quality level among transmission signals received by the receivers of the two connected systems,
The link aggregation circuit is
The transmission apparatus according to claim 6, wherein the transmission apparatus is connected to a hitless switch corresponding to the other system and outputs a transmission signal output from the connected hitless switch. A reception method by a transmission apparatus that includes two receivers that respectively belong to two systems and wirelessly receive transmission signals using different frequencies,
If both of the two systems are normal,
The reception mode switch has a step of transitioning to the first reception mode and accumulating and outputting transmission signals received by the respective receivers of the two systems,
If one of the two systems fails first,
The receiver of said one system changes the frequency to the frequency of the other system;
The reception mode switch transits to the second reception mode, and a reception quality level is high among transmission signals received using the frequency of the other system at the receiver of each of the two systems. Outputting the other transmission signal. After the one system becomes defective in transmission, until the predetermined condition is satisfied regardless of whether the other system becomes defective in transmission,
The receiver of the one system leaving the frequency at the frequency of the other system;
The reception method according to claim 11, further comprising: the reception mode switching unit keeping the second reception mode. The predetermined condition is that a state in which both of the two systems are normal continues for a certain period of time,
When the predetermined condition is satisfied,
The receiver of the one system returns the frequency to the frequency of the one system;
The reception method according to claim 12, further comprising a step of returning the reception mode switch to the first reception mode. The transmission failure is that the amount of waveform distortion calculated for the transmission signal received by the receiver is less than or equal to a threshold by the receiver.
The predetermined condition is that the amount of waveform distortion recalculated by temporarily returning the frequency to the frequency of the one system by the receiver of the one system exceeds a threshold value,
When the predetermined condition is satisfied,
The receiver of the one system returns the frequency to the frequency of the one system;
The reception method according to claim 12, further comprising a step of returning the reception mode switch to the first reception mode. A transmission apparatus that includes two receivers that belong to two systems and receive transmission signals wirelessly using different frequencies,
If both of the two systems are normal,
Transition to the first reception mode, causing the transmission signals received at the respective receivers of the two systems to be stacked and output,
If one of the two systems fails first,
Changing the frequency of the receiver of the one system to the frequency of the other system;
Transition to the second reception mode, and output a transmission signal having a higher reception quality level among transmission signals received using the frequency of the other system at the receiver of each of the two systems. A program that executes a procedure.

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