WO2004025879A1

WO2004025879A1 - Optical radio communication system, optical radio communication apparatus, optical radio communication method, and program

Info

Publication number: WO2004025879A1
Application number: PCT/JP2002/009214
Authority: WO
Inventors: Takumi Nagai
Original assignee: Allied Telesis Holdings K.K.
Priority date: 2002-09-10
Filing date: 2002-09-10
Publication date: 2004-03-25
Also published as: JPWO2004025879A1; AU2002335383A1

Abstract

An optical radio communication system for performing optical radio communication outdoors between a first optical radio communication apparatus and a second optical radio communication apparatus. The system includes an environment judgment unit for judging a communication environment of optical radio communication outdoors and a communication control unit for modifying the communication speed of optical radio communication according to the communication environment.

Description

Technical Field Optical wireless communication system, optical wireless communication device, optical wireless communication method, and program

The present invention relates to an optical wireless communication system, an optical wireless communication device, an optical wireless communication method, and a program. Background art

Conventionally, a communication system using an optical wireless system has been used. This system enables wireless communication using light as a medium between multiple spatially separated points.

However, when the above system is installed outdoors, it is affected by the shielding and diffusion of light, which is the communication medium, due to changes in the outdoor environment such as weather, etc., and the communication speed, communication quality, and communication connection itself May not be able to hold. Therefore, an object of the present invention is to provide an optical wireless communication system, an optical wireless communication device, an optical wireless communication method, and a program that can solve the above-mentioned problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention. Disclosure of the invention

In order to achieve such an object, according to a first aspect of the present invention, optical wireless communication is performed between a first optical wireless communication device and a second optical wireless communication device outdoors. An optical wireless communication system comprising: an environment determining unit that determines an outdoor communication environment of optical wireless communication; and a communication control unit that changes a communication speed of optical wireless communication based on the communication environment. An optical wireless communication system is provided.

Further, the second optical wireless communication device includes a transmission control unit that sends a test signal used for communication control to the first optical wireless communication device between a plurality of packets of the optical wireless communication. In addition, the environment determination unit may determine a communication environment according to a test signal reception state in the first optical wireless communication device.

The information processing apparatus may further include a weather information acquisition unit that acquires weather information corresponding to an area where the optical wireless communication system is installed from outside, and the environment determination unit may determine a communication environment based on the weather information. .

Further, the weather information acquisition unit may acquire the weather information by measuring an outdoor environment including at least one of outdoor temperature, humidity, atmospheric pressure, and rainfall.

Also, the communication control unit changes the communication speed of the optical wireless communication by changing the number of times one packet used for the optical wireless communication is redundantly transmitted based on the communication environment. The communication control unit further includes: a plurality of light emitting units that emit light; and a plurality of light receiving units that are provided corresponding to the plurality of light emitting units and respectively receive light emitted by the plurality of light emitting units. The communication speed of the optical wireless communication may be changed by setting, based on the communication environment, whether to transmit the same packet or different packets by using a plurality of light receiving units.

In addition, when the communication control unit sets to transmit each of the plurality of packets redundantly, the communication control unit receives the packet based on the value obtained by adding the signal values of the plurality of light beams having different wavelengths respectively received by the plurality of light receiving units. A reception control unit for converting a plurality of buckets into electric signals may be further provided.

The communication control unit further includes a wired communication unit that communicates with an external device via a wired communication medium.The communication control unit further notifies the external device of the setting of the communication speed of the optical wireless communication by the wired communication unit. The communication speed of the wired communication unit with the external device may be matched with the communication speed of the optical wireless communication.

The communication control unit further includes a wired communication unit that communicates with an external device through a wired communication medium.The communication control unit further uses an auto negotiation function that detects a maximum communicable speed by sending control signals to each other. The communication speed of the wired communication unit with the external device may be matched to the communication speed of the optical wireless communication. An optical wireless communication device that performs optical wireless communication outdoors, an environment determining unit that determines an outdoor communication environment of optical wireless communication, and changes a communication speed of the optical wireless communication based on the communication environment. A communication control unit may be provided.

According to a second aspect of the present invention, there is provided an optical wireless communication method for performing optical wireless communication between a first optical wireless communication device and a second optical wireless communication device outdoors, comprising: And a step of changing the communication speed of the optical wireless communication based on the communication environment.

According to a third aspect of the present invention, there is provided a program for causing a computer to function outdoors as a management device for managing optical wireless communication between a first optical wireless communication device and a second optical wireless communication device, comprising: And a communication control unit that changes a communication speed of the optical wireless communication based on the communication environment.

Note that the above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features may also be an invention. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a functional block diagram of the optical wireless communication system 10.

FIG. 2 is a diagram showing details of functions of a light receiving unit 200 and a reception control unit 210. FIG. 3 is a diagram showing a communication flow when the optical wireless communication system 10 starts communication.

FIG. 4 is a diagram showing a communication flow when the optical wireless communication system 10 improves the communication speed.

FIG. 5 is a diagram showing a communication flow when the optical wireless communication system 10 lowers the communication speed.

FIG. 6 is a diagram showing an example of a hardware configuration of the information processing device 25. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the claims, and all of the special combinations described in the embodiments are examples of the present invention. It is not always necessary for the solution. FIG. 1 shows a functional block diagram of the optical wireless communication system 10. The optical wireless communication system 10 includes a first optical wireless communication device 20, an information processing device 25 connected to the outside of the optical wireless communication device 20 via a wired communication medium, and a first optical wireless communication device. The apparatus includes a second optical wireless communication device 30 that performs optical wireless communication with the device 20 and an information processing device 35 that is connected to the outside of the optical wireless communication device 30 by a wired communication medium.

The optical wireless communication device 20 is used by being installed outdoors, and performs optical wireless communication with the optical wireless communication device 30 that is installed elsewhere outdoors. For example, the optical wireless communication device 20 and the optical wireless communication device 30 are provided in two buildings apart from each other, and perform optical wireless communication between these two buildings. Further, the optical wireless communication device 20 and the optical wireless communication device 30 may be installed indoors, and may transmit light between the optical wireless communication device 20 and the optical wireless communication device 30 via the outside. As described above, since the optical wireless communication device 20 and the optical wireless communication device 30 perform communication outdoors, the communication speed is changed based on the communication environment outdoors, and the occurrence of communication errors is prevented.

The information processing device 25 is installed indoors or the like, and communicates with the information processing device 35 via the optical wireless communication of the optical wireless communication device 20 and the optical wireless communication device 30. Further, the information processing device 25 may function as a management device that manages the optical wireless communication system 10 and the like. The optical wireless communication device 30 and the information processing device 35 have substantially the same configuration as the optical wireless communication device 20 and the information processing device 25, respectively.

The optical wireless communication device 20 includes a light receiving unit 200, a reception control unit 210, a wired communication unit 215, a weather information acquisition unit 220, and an environment determination unit 240. A communication control unit 250; a transmission control unit 260; a light-emitting unit 270A to C; The reception control unit 210 receives a test signal used for communication control from the optical wireless communication device 30 via the light receiving unit 20 ° between a plurality of buckets for transferring data of the optical wireless communication. Then, reception control section 210 analyzes the reception state of the test signal, and sends the analysis result to environment determination section 240. For example, the reception control unit 210 receives a test signal transmitted at a constant intensity for a predetermined period, analyzes information on a change in the intensity, and sends the information to the environment determination unit 240.

The reception control unit 210 also analyzes the error rate of the test signal based on error detection and correction code information such as CRC (abbreviation of Cyclic Redundancy Code) added to the test signal and analyzes the error rate of the test signal. You can send it to 240. The light receiving unit 200 and the reception control unit 210 receive data by receiving light from the optical wireless communication device 30. For details, the operation of the light reception unit 300 and the reception control unit 310 will be described. It will be described later.

The wired communication unit 215 sends the packet received from the information processing device 25 to the transmission control unit 260. In addition, the wired communication unit 2 15 sends the data of the optical wireless communication received from the optical wireless communication device 30 to the information processing device 25. The details will be described later as the operation of the wired communication unit 3 15 .

The weather information acquisition unit 220 acquires weather information such as weather information and natural disaster information corresponding to the area where the optical wireless communication system 10 is installed from an external network, and sends the acquired information to the environment determination unit 240. For example, the weather information acquisition unit 220 periodically acquires the weather information from a specific address on the Internet, and formats the weather information in a predetermined format (for example, XML: Extensible Markup Language). May be converted to That is, for example, the weather information acquiring unit 220 may use XML describing the weather, the probability of precipitation, and the like for each time zone as the predetermined format. Then, the weather information acquisition unit 220 may transmit this weather information to the environment judgment unit 240 in response to a request from the environment judgment unit 240 or periodically.

In addition, the weather information acquisition unit 220 outputs the outdoor temperature, humidity, atmospheric pressure, or low rainfall. Measure the outdoor environment, including at least one. Then, the weather information acquisition unit 220 sends the measured outdoor environment to the environment determination unit 240 as weather information.

The environment determination unit 240 receives the analysis result of the reception state of the test signal used for communication control from the reception control unit 210 and the weather information from the weather information acquisition unit 220. Then, environment determining section 240 determines the outdoor communication environment based on the analysis result of the reception state of the test signal and the weather information, and sends it to communication control section 250. For example, by combining these pieces of information, the environment determination unit 240 can determine weather and weather conditions, volcanic ash fallout, and the passage of birds, animals, and other shields as an outdoor communication environment. Good. For example, when receiving the weather information such as rain, snow, and fog, the environment determination unit 240 may determine that the outdoor communication environment is poor. The environment determination unit 240 may determine that the communication environment outdoors is bad when the variation of the test signal received by the reception control unit 210 is larger than a predetermined amount. Based on the outdoor communication environment received from the environment judgment unit 240, the communication method is changed by changing the communication method of optical wireless communication. The communication method change instruction is received by the reception control unit 210, the wired communication unit 2 15 and the transmission control section 260. For example, the communication control unit 250 may send, as the communication method change instruction, a frame size change instruction for changing the frame size of a bucket used for optical wireless communication, or a communication for changing the communication rate of optical wireless communication. A rate change instruction may be sent, or a redundancy number change instruction for changing the number of times one bucket used for optical wireless communication is redundantly transmitted may be sent. In addition, the communication control unit 250 has a power to transmit one packet in optical wireless communication in parallel by the light-emitting units 270A to C, or the bucket transmits the packets to each of the light-emitting units 270A to 270C. A multiplicity change instruction indicating whether or not to transmit serially in duplicate may be sent as a communication method change instruction.

The transmission control unit 260 converts the bucket received from the wired communication unit 215 into a frame size change instruction, a communication rate change instruction, a redundant number change instruction, or a multiplicity change instruction received from the communication control unit 250. It converts to an electric signal by the communication method based on the communication method change instruction, etc., and sends it to the light emitting units 270A-C. Also, the transmission control unit 260 A test signal used for communication control is generated, and is sent to the light emitting units 270A-C between electric signals corresponding to a plurality of packets received from the wired communication unit 215. For example, the transmission control unit 260 transmits the test signal at a constant intensity and a constant intensity for the light emitting units 270 AC. In addition, the transmission control unit 260 sends a communication method change instruction to the optical wireless communication device 30 via the light emitting units 270A to 270C.

Each of the light-emitting units 270 A to C converts the electrical signal and the test signal received from the transmission control unit 260 into light having a different wavelength, and uses the light-emitting lens 272 to perform optical wireless communication. Light is emitted toward the device 30. Each of the light emitting units 270 A to C may emit laser light, infrared light, or the like, as light, to the optical wireless communication device 30.

The optical wireless communication device 30 includes a light receiving unit 300, a reception control unit 310, a wired communication unit 315, a weather information acquisition unit 320, an environment determination unit 340, and information processing. The device includes a device 350, a transmission control unit 36.0, and light-emitting units 370A to C.

In the optical wireless communication device 30, the light receiving unit 300, the reception control unit 310, the wired communication unit 315, the weather information acquisition unit 320, the environment determination unit 340, and the information processing unit , The transmission control unit 360, and the light emitting units 370 A to C, respectively, the light receiving unit 200 in the optical wireless communication device 20, the reception control unit 210, and the wired Communication unit 215, weather information acquisition unit 220, environment judgment unit 240, information processing unit 250, transmission control unit 260, light emitting unit 270A to C It has substantially the same configuration. The configuration and operation for transmitting the light are the same as the configuration and operation of the corresponding members in the optical wireless communication device 20, and thus the description is omitted, and the light received from the optical wireless communication device 20 is processed. The configuration and operation for this will be described below. Also, in the above, instead of the light emitting units 270 A to C emitting light toward the optical wireless communication device 30, each of the light emitting units 370 A to C is provided with the optical wireless communication device 2. Emit light toward zero.

The light receiving unit 3000 receives light for transmitting data from the light emitting units 270A to C, converts the light into electric signals, and sends the electric signals to the reception control unit 310. When receiving a communication method change instruction from the optical wireless communication device 30 via the light receiving unit 300, the reception control unit 310 sends the instruction to the communication control unit 3 via the environment determination unit 340. Send to 5 0. In response, the communication control unit 350 sends the communication method change instruction received from the reception control unit 310 to the reception control unit 310, the wired communication unit 315, and the transmission control unit 360. send.

Further, the reception control unit 310 converts the data converted into the electric signal received from the light receiving unit 300 into a bucket using a communication method based on the communication method change instruction received from the communication control unit 350. Convert it and send it to the wired communication unit 315 and the environment judgment unit 340. For example, when the reception control unit 310 receives from the communication control unit 350 an instruction to redundantly transmit one bucket used for optical wireless communication a predetermined number of times, the reception control unit 310 receives the instruction from the light reception unit 300. A packet with a smaller communication error is selected from among the buckets of the number of redundancy indicated by the signal, and the selected packet is sent to the wired communication unit 315 and the environment judgment unit 340.

The wired communication unit 315 sends the packet received from the reception control unit 310 to the information processing device 35. When receiving a frame size change instruction from the communication control unit 250 as a communication method change instruction, the wired communication unit 315 sends the instruction to the information processing device 35 to reduce the frame size of the packet. change.

In addition, when receiving the communication method change instruction from the communication control unit 350, the wired communication unit 315 transmits the information of the communication speed setting of the optical wireless communication to the information processing device 305 as an external device. To make the communication speed with the information processing device 35 match the communication speed of the optical wireless communication. In addition, the wired communication unit 315 uses an auto-negotiation function to detect the maximum communicable speed by transmitting control signals to each other, and uses the auto-negotiation function to determine the communication speed with the information processing device 35 for optical wireless communication. It may be adjusted to the communication speed. For example, the wired communication unit 315 may follow the communication method change instruction from the communication control unit 350 so that the communication speed of the wired communication medium with the information processing device 35 does not exceed the communication speed of the optical wireless communication. The communication speed with the information processing device 35 using a wired communication medium is matched. Here, the light receiving unit 200 in the optical wireless communication device 20 has substantially the same configuration as the light receiving unit 300 in the optical wireless communication device 30. However, instead of the light receiving unit 300 receiving light for transmitting data from the optical wireless communication device 20, the light receiving unit 200 receives the light from the optical wireless communication device 30.

In the present embodiment, the optical wireless communication device 20 includes a weather information acquisition unit 220, an environment determination unit 240, and a communication control unit 250 in the optical wireless communication device 20. However, instead of this, the information processing device 25 may include a weather information acquisition unit 220, an environment determination unit 240, and a communication control unit 250. Further, a control device that is provided outside the optical wireless communication device 20 and controls the optical wireless communication device 20 and a control board that is a base on which the control device is mounted are provided with a weather information acquisition unit 220 and an environmental information It may include a communication unit 240 and a communication unit 250.

As described above, the optical wireless communication system 10 changes the communication speed of the optical wireless communication based on the outdoor communication environment. Therefore, the optical wireless communication system 10 reduces the deterioration of the communication state by lowering the communication speed and improving the communication quality and communication redundancy even when the outdoor communication environment deteriorates due to an unexpected situation. Thus, disconnection of communication can be prevented. FIG. 2 shows details of the functions of the light receiving unit 200, the reception control unit 210, and the transmission control unit 260. As shown in FIG. 2 (Α), the transmission control unit 260 includes a serial-parallel converter 262, a duplicator 2664, and a selector 2666. The serial-to-parallel converter 266 converts the serial electric signal indicating the bucket received from the wired communication unit 215 into parallel, and sends it to the selector 266. On the other hand, the duplicator 264 sends the electric signal indicating the packet received from the wired communication unit 215 to the selector 266 as three overlapping electric signals.

The selector 266 selects one of the electric signals received from the serial-parallel converter 262 or the duplicator 264 according to the communication method change instruction from the communication control unit 250, and Send to 270 AC. For example, if selector 2 6 6 is a serial When a bucket is generated based on the electric signal received from the parallel converter 262 and sent to the light emitting units 270 A to C, the transmission control unit 260 emits one bucket in the optical wireless communication. The transmission can be performed in parallel by the units 270A to C.

On the other hand, when a packet is generated based on the electric signal received from the selector 266 and the electric signal received from the duplicator 264 and sent to the light emitting units 270A to C, the transmission control unit 260 , And each of the light-emitting units 270 A to C can be transmitted in series.

As described above, the communication control unit 250 uses the light-emitting units 270A to C and the light-receiving units 370A to C to transmit the same packet or different packets. Is set based on the outdoor communication environment, the communication speed of the optical wireless communication can be changed.

In the present embodiment, when transmitting different packets, the communication control unit 250 transmits electric signals obtained by dividing one frame constituting data into three by the light emitting units 270 A to C. However, as another example, the communication control unit 250 may transmit frames different from each other by the light emitting units 270A to 270C. As shown in FIG. 2 (B), the light receiving unit 200 is composed of a light receiving lens 202, a spectroscope 204, light receiving sections 205A to C, and a color filter 207A to C. And

The light receiving side lens 202 receives the light mixed with the lights having different wavelengths emitted by the optical wireless communication devices 307 A to C, and sends the light to the spectroscope 204.

The spectroscope 204 splits the light received from the light-receiving lens 202 into three light beams, and sends them to the light-receiving unit 205A, the light-receiving unit 205B, and the light-receiving unit 205C, respectively. send.

The light receiving sections 205 A to C are provided corresponding to the light emitting sections 370 A to C, and pass the light received from the spectroscope 204 through the color filters 207 A to C having different colors from each other. The light of the first wavelength, the light of the second wavelength, and the light of the third wavelength, respectively. To convert each light into an electric signal. Then, the light receiving units 205 A to C send the converted electric signals to the reception control unit 210. As described above, the light receiving units 205 AC can receive the light emitted from the light emitting units 370 AC, respectively.

The reception control unit 210 includes an adder 2 12, a parallel-serial converter 2 14, and a selector 2 16. The adder 212 adds the signal values of the electric signals received from the light-receiving units 205 A to C to analog signals and sends them to the selector 216. The parallel-to-serial converter 216 serially converts the electric signals received from the light receiving units 205 to AC to the selector 216. The selector 2 16 selects one of the electric signals received from the adder 2 12 or the parallel-to-serial converter 2 14 according to the multiplicity change instruction from the communication control unit 250, and selects the wired communication unit. 2 15 and sent to the environmental judgment section 240. For example, when the multiplicity change instruction indicating that the multiplicity is to be reduced is received from the communication control unit 250, the selector 2 16 receives the bucket based on the electric signal received from the parallel-to-serial converter 2 14. Is generated and sent to the wired communication unit 215 and the environment judgment unit 240. On the other hand, the selector 216 generates a bucket based on the electric signal received from the adder 212 when receiving a multiplicity change instruction from the communication control unit 250 indicating that the multiplicity is to be increased. And sends it to the wired communication section 2150 and the environment judgment section 240.

As described above, the communication control unit 350 transmits the one packet in the optical wireless communication in parallel by the light emitting units 370A to C, or transmits this packet to each of the light emitting units 370A to 370A. In a case where C is set to be transmitted serially in duplicate, the reception control unit 210 transmits the light received from each of the light-emitting units 370A to C to the instruction from the communication control unit 250. It can be converted to a bucket appropriately.

When the transmission control unit 360 transmits one packet in the optical wireless communication in parallel by the light emitting units 370 A to C, the light receiving unit 200 sets the color filters 207 A to C need not be used. In this case, the light receiving sections 205 A to C do not use the color filters 207 A to C for the light separated by the spectroscope 204. Since it is possible to receive light intensely, it is possible to receive stronger light and reduce errors in received data.

FIG. 3 shows a communication flow when the optical wireless communication system 10 starts communication. The information processing device 25 sends a communication start request to the optical wireless communication device 20 (S 3 00). The transmission control unit 360 performs communication between a plurality of packets used for optical wireless communication data transmission. A test signal to be used for the control of is transmitted to the optical wireless communication device 20 (S310). As shown in the figure, the transmission control unit 360 transmits a test signal only before the optical wireless communication system 10 starts communication, but as another example, the transmission control unit 360 The test signal may be periodically sent to the optical wireless communication device 20 even in cases other than before the start of the test.

Upon receiving the communication start request from the information processing device 25, the optical wireless communication device 20 changes the outdoor communication environment based on the weather information and the analysis result of the reception state of the test signal received from the transmission control unit 360. Judge (S320). The communication control unit 250 sets the wireless communication method and the wireless communication speed based on the determination, and notifies the optical wireless communication device 30 (S330). The wired communication unit 215 notifies the information processing device 25 of the set wireless communication speed (S3'40). Further, the wired communication unit 315 notifies the information processing device 35 of the notified wireless communication speed (S350).

The optical wireless communication device 20 starts communication with the optical wireless communication device 30 according to the wireless communication method and the wireless communication speed set by the communication control unit 250 (S355). The optical wireless communication device 30 starts communication with the optical wireless communication device 20 based on the wireless communication speed notified from the optical wireless communication device 20 (S360).

Subsequently, the communication control unit 250 starts communication with the information processing device 25 at a wire communication speed equal to or lower than the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. The communication speed between the wired communication unit 211 and the information processing device 25 is matched with the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30 (S370). . The information processing device 25 is connected to the optical wireless communication device 20 and the optical Based on the wireless communication speed between the wireless communication devices 30, communication with the optical wireless communication device 20 is started at a wire communication speed lower than or equal to the wireless communication speed (S380). The operation of S390 in the optical wireless communication device 30 and the operation of S395 in the information processing device 35 are the operation of S370 and the information processing device 25 in the optical wireless communication device 20, respectively. Since the operation is almost the same as that of S380 in, the description is omitted.

As another example, the communication control unit 250 communicates with the information processing device 25 at the same wired communication speed as the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. By starting, the wireless communication speed between the wired communication unit 2 15 and the information processing device 25 may be matched with the wired communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. As shown in the above communication flow, the optical wireless communication system 10 can start communication at a speed set based on the outdoor communication environment of the optical wireless communication. The optical wireless communication system 10 starts wired communication with the information processing device 25 by the optical wireless communication device 20 after the communication between the optical wireless communication device 20 and the optical wireless communication device 30 starts. Accordingly, in the optical wireless communication system 10, the information processing device 25 and the optical wireless communication device 20 start communication, and the wireless communication between the optical wireless communication device 20 and the optical wireless communication device 30 is not started. Since the state can be avoided, it is possible to prevent an error or the like in which data transmitted from the information processing device 25 overflows from the buffer of the optical wireless communication device 20. FIG. 4 shows a communication flow when the optical wireless communication system 10 improves the communication speed. The information processing device 25 sends a communication speed change request indicating that the communication speed is to be improved to the optical wireless communication device 20 (S400). The operation of S410, S420, S430, S440, and S450 in this figure is the operation of S310, S320, S330 in FIG. , S340, and S350 are substantially the same, and therefore, description thereof is omitted.

The optical wireless communication device 20 improves the wireless communication speed by changing the wireless communication speed with the optical wireless communication device 30 to the speed set by the communication control unit 250. (S455). The optical wireless communication device 30 improves the wireless communication speed by changing the wireless communication speed with the optical wireless communication device 20 to the speed notified from the optical wireless communication device 20 (S46) 0).

Subsequently, the communication control unit 250 needs to improve the wired communication speed with the information processing device 25 within a range not more than the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. With this, the wire communication speed with the information processing device 25 via the wire communication unit 2 15 is matched with the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30 (S 47 0). Based on the wireless communication speed notified from the optical wireless communication device 20, the information processing device 25 improves the wired communication speed with the optical wireless communication device 20 at a wired communication speed equal to or lower than the wireless communication speed (S 480). The operation of S490 in the optical wireless communication device 30 and the operation of S495 in the information processing device 35 are the operation of S470 in the optical wireless communication device 20 and the operation of S490 in the information processing device 25, respectively. Since the operation is almost the same as that of 480, the description is omitted.

As shown in the above communication flow, the optical wireless communication system 10 can improve the communication speed based on the speed set based on the outdoor communication environment of the optical wireless communication. In addition, the optical wireless communication system 10 communicates the change of the wired communication speed between the optical wireless communication device 20 and the information processing device 25 with the optical wireless communication device 20 and the optical wireless communication device 30. Perform after changing the communication speed. Therefore, during the change of the communication speed, the optical wireless communication system 10 changes the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30 to the optical wireless communication device 20 and the information processing device 25. It is possible to prevent the speed from being lower than the wired communication speed between the two. As a result, the optical wireless communication system 10 can prevent an error due to buffer overflow of the optical wireless communication device 20 or the like. FIG. 5 shows a communication flow when the optical wireless communication system 10 lowers the communication speed. The information processing device 25 sends a communication speed change request indicating a reduction in the communication speed to the optical wireless communication device 20 (S500). S 5 10 and S 5 in this figure The operations of 20, S530, S540, and S550 are almost the same as the operations of S310, S320, S330, S340, and S350 in FIG. The explanation is omitted.

The communication control unit 250 reduces the wired communication speed with the information processing device 25 within a range equal to or less than the wireless communication speed set between the optical wireless communication device 20 and the optical wireless communication device 30 (S55). Five) . The information processing device 25 reduces the wire communication speed to a speed equal to or lower than the wireless communication speed based on the wireless communication speed notified from the optical wireless communication device 20 (S560).

The operations of S570 and S58◦ in the optical wireless communication device 30 and the information processing device 35 are substantially the same as the operations of S555 and S560 in the optical wireless communication device 20 and the information processing device 25, respectively. Description is omitted because there is.

Subsequently, the optical wireless communication device 20 lowers the wireless communication speed by changing the wireless communication speed with the optical wireless communication device 30 to the speed set by the communication control unit 250 (S590) . The optical wireless communication device 30 reduces the wireless communication speed by changing the wireless communication speed with the optical wireless communication device 20 to the speed notified from the optical wireless communication device 20 (S595).

As shown in the above communication flow, the optical wireless communication system 10 can reduce the wireless communication speed based on the speed set based on the outdoor communication environment of the optical wireless communication. In addition, the optical wireless communication system 10 reduces the decrease in the wired communication speed of the optical wireless communication device 20 with the information processing device 25 by reducing the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. Before the communication speed is changed, the wire communication speed between the optical wireless communication device 20 and the information processing device 25 becomes lower than the wireless communication speed between the optical wireless communication device 20 and the optical wireless communication device 30 during the change of the communication speed. It can be prevented from lowering. FIG. 6 shows an example of a hardware configuration of the information processing device 25. The information processing device 25 includes a CPU 700, a ROM 702, a RAM 704, a communication interface 706, and a It has a hard disk drive 708, a database interface 710, a flexible disk drive 712, and a CD-ROM drive 714. The CPU 700 operates based on the programs stored in the ROM 702 and the RAM 704, and controls each unit. The communication interface 706 communicates with the optical wireless communication device 20 via a computer network. The database interface 710 writes data to the database and updates the contents of the database.

The flexible disk drive 712 reads data or a program from the flexible disk 720 and provides it to the communication interface 706. The CD-ROM drive 714 reads data or a program from the CD-ROM 722 and provides it to the communication interface 706. The communication interface 706 transmits the data or program provided from the flexible disk drive 712 or the CD-ROM drive 714 to the optical wireless communication device 20. The database interface 710 is connected to various databases 724 to transmit and receive data.

The program provided to the optical wireless communication device 20 is stored in a recording medium such as a flexible disk 720 or a CD-ROM 72 and provided by a user. The program stored in the recording medium may be compressed or uncompressed. The program is read from the recording medium, installed in the optical wireless communication device 20 via the communication interface 706, and executed in the optical wireless communication device 20.

The programs that implement the optical wireless communication device 20 include a light receiving unit function module, a light receiving unit function module, a reception control module, an addition module, a parallel-to-serial conversion module, a wired communication module, and a selector module. A weather information acquisition module, an environment determination module, a communication control module, a transmission control module, a serial-to-parallel conversion module, a duplication module, a selector module, and a light emitting module. These modules add the optical wireless communication device 20 to the light receiving unit 200, the light receiving unit 205, and the receiving control unit 210. , Parallel-serial converter, wired communication unit, selector, weather information acquisition unit, environment judgment unit, communication control unit This is a program that operates as 250, a transmission control unit 260, a serial-to-parallel converter 262, a duplicator 264, a selector 260, and a light emitting unit 270.

A flexible disk 720 or a CD-ROM 722 as an example of a recording medium stores some or all of the functions of the operation of the optical wireless communication device 20 in all the embodiments described in the present application. be able to.

These programs may be read out directly from the recording medium by the optical wireless communication device 20 and executed, or may be executed in the optical wireless communication device 20 after being installed in the optical wireless communication device 20. Further, the program may be stored on a single recording medium or on a plurality of recording media. Also, it may be stored in a form encoded by encryption, compression, or the like.

Recording media include flexible disks, CD-ROMs, optical recording media such as DVDs and PDs, magneto-optical recording media such as MDs, tape media, magnetic recording media, and semiconductor memories such as IC cards and miniature cards. Can be used. Also, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the optical wireless communication device 20 via the communication network. Good.

As is clear from the above description, the optical wireless communication system 10 can change the communication speed based on the outdoor communication environment of the optical wireless communication. Therefore, the optical wireless communication system 10 can change the communication speed and resistance to noise based on the outdoor communication environment, realizing an appropriate communication environment that responds to changes in the outdoor communication environment. can do.

In addition, the optical wireless communication system 10 must match the communication speed of the optical wireless communication device 20 with the information processing device 25 to the communication speed between the optical wireless communication device 20 and the optical wireless communication device 30. Can be. Therefore, the optical wireless communication system 10 performs data communication using optical wireless communication between the information processing device 25 and the information processing device 35. It can be done properly. Although the embodiments of the present invention have been described above, the technical scope of the present invention according to the present application is not limited to the above embodiments. The invention described in the claims can be implemented by adding various changes to the above embodiment. It is also apparent from the claims that such an invention belongs to the technical scope of the invention of the present application. Industrial applicability

As is clear from the above description, according to the present invention, it is possible to realize appropriate optical wireless communication corresponding to a change in an outdoor communication environment.

Claims

The scope of the claims

1. An optical wireless communication system that performs optical wireless communication between a first optical wireless communication device and a second optical wireless communication device outdoors.

An environment determining unit that determines a communication environment of the optical wireless communication outdoors,

A communication control unit that changes a communication speed of the optical wireless communication based on the communication environment;

An optical wireless communication system comprising:

2. The second optical wireless communication device is a transmission control unit that sends a test signal used for communication control to the first optical wireless communication device between a plurality of packets of the optical wireless communication. Further comprising

2. The optical wireless communication system according to claim 1, wherein the environment determining unit determines the communication environment according to a reception state of the test signal in the first optical wireless communication device.

3. It further comprises a weather information acquisition unit for acquiring weather information corresponding to an area where the optical wireless communication system is installed from the outside,

The optical wireless communication system according to claim 1, wherein the environment determining unit determines the communication environment based on the weather information.

4. The optical wireless device according to claim 3, wherein the weather information acquisition unit acquires the weather information by measuring an outdoor environment including at least one of an outdoor temperature, a humidity, an atmospheric pressure, and a rainfall amount. Communications system.

5. The communication control unit changes the communication speed of the optical wireless communication by changing the number of times one packet used for the optical wireless communication is redundantly transmitted based on the communication environment. The optical wireless communication system according to claim 1, wherein

6. A plurality of light-emitting portions that emit light having different wavelengths from each other;

A plurality of light receiving units provided corresponding to the plurality of light emitting units and respectively receiving light emitted by the plurality of light emitting units; The communication control unit uses the plurality of light emitting units and the plurality of light receiving units to transmit the same packet or to transmit different packets based on the communication environment. The optical wireless communication system according to claim 1, wherein a communication speed of the optical wireless communication is changed.

7. When the communication control unit sets to transmit each of the plurality of packets redundantly, the signal values of the plurality of lights having different wavelengths respectively received by the plurality of light receiving units are added. 7. The optical wireless communication system according to claim 6, further comprising a reception control unit configured to convert the plurality of received packets into an electric signal based on the value.

8. A wired communication unit for communicating with an external device via a wired communication medium is further provided.

The communication control unit further notifies the external device of the setting of the communication speed of the optical wireless communication by the wired communication unit, so that the communication speed of the wired communication unit with the external device is controlled by the optical communication unit. 2. The optical wireless communication system according to claim 1, wherein the communication speed is matched with the communication speed of the wireless communication.

9. A wired communication unit that communicates with an external device via a wired communication medium is further provided.

The communication control unit further uses an auto negotiation function that detects a maximum communication speed by sending control signals to each other, and determines a communication speed of the wired communication unit with the external device by the optical wireless communication. 2. The optical wireless communication system according to claim 1, wherein the communication speed is adjusted to a communication speed of the communication.

10. An optical wireless communication device that performs optical wireless communication outdoors.

An optical wireless communication device comprising:

1 1. An optical wireless communication method for performing optical wireless communication between a first optical wireless communication device and a second optical wireless communication device outdoors,

Judging the outdoor communication environment of the optical wireless communication, Changing the communication speed of the optical wireless communication based on the communication environment.

1 2. A program that causes a computer to function as a management device that manages optical wireless communication between a first optical wireless communication device and a second optical wireless communication device outdoors.

Said computer,

A program characterized by functioning.