KR101990372B1 - Lighting system using wireless optical communication - Google Patents

Abstract

A wireless optical communication based illumination system is disclosed. The wireless optical communication based illumination system includes a plurality of illumination units and a communication relay unit. The plurality of illumination units communicate with each other with a communication module that performs wireless optical communication. The communication relay unit includes communication modules that are located in overlapping areas where the light emission areas of the communication modules provided in adjacent illumination units overlap, . By providing the communication relay unit in the area where the light emitting areas of the communication modules provided in adjacent lighting units are overlapped with each other, even when an obstacle obstructing the wireless communication is located between the illuminating lamps performing the wireless optical communication, Can be controlled.

Description

TECHNICAL FIELD [0001] The present invention relates to a lighting system based on wireless optical communication,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination system, and more particularly, to an illumination system for controlling a plurality of illumination lamps using communication between illumination lamps.

Generally, indoor lighting such as a fluorescent lamp, an incandescent lamp and a halogen lamp is attached to a ceiling or a wall of a room in a room installed in a home or an office space. However, LED lighting having advantages of energy efficiency and power consumption reduction In order to increase the productivity.

On the other hand, as the number of lights installed in the room increases, a plurality of switches for lighting and extinguishing each of the lights are installed in the form of being buried in the wall, or a switch for turning on or off all or a part of the switches is installed.

However, when a plurality of switches are installed, the user must be aware of the switches of the corresponding lamps, and if a batch switch is installed, the lamps can not be selected and turned on / off arbitrarily.

In recent years, there has been an increasing number of cases in which a control box capable of controlling a plurality of lights is installed for the convenience of the user. However, such a control box is also installed on the wall surface of each zone, and further, it is difficult to change the structure because it is formed in the form of a wire.

In order to solve these problems, an illumination system has been recently introduced, in which a wireless communication module is installed in each of a plurality of illumination lamps and a plurality of illumination lamps are controlled using wireless communication between illumination lamps. 1 is a schematic view showing the concept of a conventional illumination system using wireless communication.

In FIG. 1, an example in which an illuminating lamp that has received a control command from the user terminal 20 transmits a control command to the adjacent illuminating lamp 10-2 using wireless communication (10-1). Since the arrangement of the illumination lamps can be implemented in various forms according to the illumination environment, an obstacle obstructing the wireless communication may be located between the illumination lamps in some cases. In this case, the illumination system using the wireless communication between the illumination lamps There arises a problem that implementation becomes difficult.

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KR 101389102 B1

The present invention has been conceived to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a wireless communication device and a wireless communication method which enable wireless communication between lighting devices even when an obstacle obstructing wireless communication is located between lighting devices performing wireless communication, And to provide a communication system that enables control of the communication device.

In order to achieve the above object, a wireless optical communication based illumination system according to the present invention includes a plurality of illumination units and a communication relay unit. The plurality of illumination units communicate with each other with a communication module that performs wireless optical communication. The communication relay unit includes communication modules that are located in overlapping areas where the light emission areas of the communication modules provided in adjacent illumination units overlap, .

By providing the communication relay unit in the area where the light emitting areas of the communication modules provided in adjacent lighting units are overlapped with each other, even when an obstacle obstructing the wireless communication is located between the illuminating lamps performing the wireless optical communication, Can be controlled.

At this time, the wireless optical communication may be wireless infrared communication. According to this configuration, it is possible to solve the disadvantage of the wireless infrared communication that the transmitter and the receiver must face, and wireless infrared communication capable of easily securing a wide bandwidth at a short distance can be effectively used for control of the illumination system .

The communication module may include a plurality of communication units whose light emission directions are set different from each other, and the communication relay unit may be disposed in an overlapping area where the opposite communication light emission areas of adjacent illumination units overlap. According to such a configuration, the illumination unit can communicate with the illumination units in various directions, thereby enabling various control of the illumination system.

At this time, the communication unit includes a first transmission / reception unit that transmits / receives light toward the communication unit of the adjacent illumination unit facing each other, and the communication relay unit can be disposed within +/- 15 degrees from the light emission direction of the first transmission / reception unit. According to such a configuration, wireless infrared optical communication can be performed without the influence of obstacles without changing the structure of a general wireless optical communication device by disposing a communication relay unit within a radiation angle of two opposing infrared transmission units.

The communication unit includes a first transmitting and receiving unit for transmitting and receiving light toward and from a communication unit of an adjacent illumination unit facing each other and a second transmitting and receiving unit for emitting light in a direction of ± 25 to ± 35 degrees from the light emitting direction of the first transmitting and receiving unit, And the communication relay unit can be disposed within +/- 15 degrees from the light radiation direction of the second transceiver unit. According to such a configuration, by adding the structure of the second transmitting unit to the general wireless optical communication structure, it is possible to exclude the effect of a wider range of communication obstacles.

The communication module may further include an angle adjusting unit for adjusting the light radiation direction of the communication unit so that the communication relay unit is located in the overlapping area. According to such a configuration, it is possible to exclude the influence of a wide range of communication obstacles without adding a separate transmitting unit.

At this time, the communication relay unit may be disposed on a fixture in a position to bypass a communication obstacle or a communication obstacle located between adjacent illumination units.

Further, the communication relay unit can receive power from a predetermined part of adjacent lighting units. According to such a configuration, it is not necessary to provide a separate power supply for the communication relay unit.

According to another aspect of the present invention, there is provided a wireless optical communication based illumination system including a plurality of illumination groups each having a plurality of illumination devices each having a communication module for performing wireless communication and transmitting / receiving a light signal in a relay manner, A system, comprising: a first illumination group, a second illumination group including a lighting device adjacent to a lighting device at a front end or a rear end of the first lighting group, and a second lighting group including a lighting device communication module adjacent to the first lighting group and the second lighting group And a communication relay unit which is disposed in an overlapping area where the radiation areas overlap and relays communication between adjacent lighting device communication modules.

According to this configuration, since the communication relay unit is provided in a region where the light emitting regions of the communication modules provided respectively in the adjacent lighting apparatuses belonging to different lighting groups are overlapped, wireless communication can be performed between the lighting lamps belonging to different lighting groups, Even when an obstacle obstructing communication is located, it is possible to control the entire lighting lamp using the wireless optical communication.

In addition, the wireless optical communication-based communication module according to the present invention is a communication module for an illumination system that wirelessly transmits / receives a lighting signal to / from adjacent lighting devices in a relay manner, A second communication unit for transmitting / receiving a lighting signal using a predetermined radio wave communication with another lighting apparatus adjacent to the communication unit, and a signal conversion unit for converting and transmitting the lighting signals received by the first and second communication units.

As described above, since the communication module includes not only the first communication unit using the wireless optical communication but also the second communication unit using the radio wave communication and the signal conversion unit converting the reception signals of the first and second communication units, Even when an obstacle obstructing the wireless communication is located, it is possible to control the entire lighting using the wireless communication.

At this time, the preset radio wave communication may be Bluetooth communication.

According to another aspect of the present invention, there is provided a wireless communication system based on a wireless communication, comprising: a plurality of lighting apparatuses for wirelessly transmitting / receiving a lighting signal in a relay manner, wherein at least two lighting apparatuses, A first communication unit that transmits and receives a lighting signal by using an adjacent lighting device and a wireless optical communication, a second communication unit that transmits and receives a lighting signal by using preset radio communication with another adjacent lighting device, and a second communication unit, And a signal converting unit for converting and transmitting one lighting signal.

At this time, two adjacent illuminating devices may be disposed with a predetermined communication obstacle in between.

In addition, an illumination device other than a predetermined illumination device among a plurality of illumination devices may be provided with a communication module including a communication section that transmits and receives a lighting signal using wireless optical communication.

According to another aspect of the present invention, there is provided a wireless optical communication based communication system including a plurality of lighting groups each having a plurality of lighting devices each having a communication module for performing wireless communication and transmitting / receiving a lighting signal in a relay manner, A second lighting group including a lighting device adjacent to the lighting device at the front or rear end of the first lighting group, a communication module of an adjacent lighting device, Lt; / RTI >

According to the present invention, since the communication relay unit is provided in the area where the light emitting areas of the communication modules provided in adjacent lighting units are overlapped, even when an obstacle obstructing the wireless communication is located between the illuminating lamps performing the wireless optical communication, It becomes possible to control the whole lighting.

In addition, it is possible to solve the disadvantage of the wireless infrared communication that the transmitter and the receiver must face, and wireless infrared communication capable of easily securing a wide bandwidth at a short distance can be effectively used for control of the illumination system.

Further, by allowing the illumination section to communicate with the illumination sections in various directions, various control of the illumination system becomes possible.

In addition, by arranging the communication relay units within the radiation angles of the two opposite infrared ray transmission units, the wireless infrared ray communication can be performed without the influence of the obstacle without changing the structure of the general wireless optical communication apparatus.

Further, by adding the structure of the second transmission unit to the general wireless optical communication structure, the influence of a wider range of communication obstacles can be excluded.

In addition, it is possible to eliminate the influence of a wide range of communication obstacles without adding a separate transmitting unit.

In addition, it is not necessary to provide a separate power supply for the communication relay unit.

Further, by providing the communication relay units in the regions where the light emitting regions of the communication modules provided respectively in the adjacent lighting apparatuses in the different lighting groups overlap, it is possible to prevent the wireless communication between the lighting lamps belonging to different lighting groups performing the wireless optical communication Even when an obstacle is located, it is possible to control the entire lighting lamp using the wireless optical communication.

The communication module includes a first communication unit using wireless optical communication as well as a second communication unit using wireless radio communication and a signal conversion unit converting signals received by the first and second communication units. Even when an obstacle obstructing communication is located, it is possible to control the entire lighting lamp using wireless communication.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the concept of a conventional illumination system using wireless communication. Fig.
2 is a schematic block diagram of a wireless optical communication based illumination system in accordance with an embodiment of the present invention.
Figure 3 shows a first embodiment of the wireless optical communication based illumination system of Figure 1;
Figure 4 shows a second embodiment of the wireless optical communication based illumination system of Figure 1;
Figure 5 illustrates a third embodiment of the wireless optical communication based illumination system of Figure 1;
Figure 6 shows a fourth embodiment of the wireless optical communication based illumination system of Figure 1;
7 is a schematic block diagram of a wireless optical communication based illumination system according to another embodiment of the present invention;
FIG. 8 illustrates an embodiment of a wireless optical communication based communication system of FIG. 7; FIG.

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

2 is a schematic block diagram of a wireless optical communication based illumination system according to an embodiment of the present invention. 2, the wireless optical communication based illumination system 100 includes a plurality of illumination units 110 and a communication relay unit 120, and the illumination unit 110 includes a communication module 112 again. The communication module 112 includes a communication unit 114 and an angle adjustment unit 118 and the communication unit 114 includes a transmission / reception unit 116 again.

The plurality of illumination units 110 may include a communication module 112 for performing wireless optical communication. At this time, the number of the lighting units 110 performing the communication may be two or more, but it is common that there are two but not limited. In addition, the light used for communication may be any kind of light capable of performing optical communication including visible light, but it will be generally infrared.

Since infrared rays have a longer wavelength than visible light, they can smoothly pass through fine particles floating in the air. If the distance between the devices is short, it is possible to secure a wide bandwidth (a channel for transmitting data) can do. Thanks to these advantages, most of the optical wireless communication devices used in modern times are adopting the infrared method.

The biggest disadvantage of infrared communication is that the distance to communicate is as short as a few meters, and the transmitter and receiver of both devices must face each other. However, these characteristics also serve as advantages. The biggest advantage is security. Since it is possible to communicate only at a short distance and at a predetermined angle, it is difficult to secretly extract or modulate data from the outside like a remote wireless communication network. In addition, since the infrared communication module has a simple structure and low production cost, it is also advantageous to mass-produce the product with the infrared communication module at low cost.

Therefore, by using infrared rays for wireless optical communication, a wide bandwidth can be easily secured at a short distance, and a system can be implemented at a low cost.

At this time, the communication module 112 may include a plurality of communication units 114 each having a different light emission direction. With such a configuration, the illumination unit 110 can communicate with other illumination units 112 in various directions, thereby enabling various control of the illumination system. At this time, although the number of the communication units 114 may be variously adjusted depending on the implementation environment, it is common that there are two.

The communication relay unit 120 relays communication between the communication modules 112 in which the light emitting regions of the communication modules 112 provided in the neighboring illumination units 110 are overlapped and the light emitting regions are overlapped. At this time, the communication relay unit 120 may be disposed in the overlapping region where the light emitting regions of the communication units 114 facing each other in the adjacent illumination units 110 overlap.

By providing the communication relay unit 120 in a region where the light emitting regions of the communication modules provided in adjacent lighting units are overlapped with each other as described above, even when an obstacle obstructing the wireless communication is located between the illumination lamps performing the wireless optical communication, So that it is possible to control the whole lighting lamp using the light source.

The communication unit 114 includes a first transmitting and receiving unit 116-1 that transmits and receives light toward the communication unit 114 of the adjacent illumination unit 110. The communication relay unit 120 includes a first transmitting and receiving unit And within ± 15 degrees from the light emission direction of the light source 116-1. According to such a configuration, by arranging the communication relay unit 120 within the radiation angle of the two opposite infrared ray transmission units 116-1, wireless infrared optical communication is performed without the influence of obstacles without changing the structure of a general wireless optical communication apparatus .

FIG. 3 is a diagram illustrating a first embodiment of the wireless optical communication based illumination system of FIG. 1; 3 shows an example in which the communication relay unit 120 is disposed within ± 15 degrees from the light emission direction of the two communication units 114 facing each other in the adjacent illumination unit 110. FIG.

FIG. 3 shows an example in which the communication relay unit 120 is disposed on the obstacle 200. As shown in FIG. 3, when the communication obstacle is small in size and located within the light emission range of the opposed communication unit 114, it may be effective to directly fix the communication relay unit 120 on the obstacle 200.

The communication unit 114 includes a first transmitting and receiving unit 116-1 for transmitting and receiving light toward and from the communication unit 114 of the adjacent illumination unit 110 and a second transmitting and receiving unit 116-1 for receiving light from the light emitting direction of the first transmitting and receiving unit 116-1 Receiving section 116-2 in the optical radiation direction spaced from ± 25 degrees to ± 35 degrees and the communication relay section 120 is provided with a distance of ± 15 degrees from the optical radiation direction of the second transceiver section 116-2, As shown in FIG. According to such a configuration, by adding the structure of the second transmitting unit to the general wireless optical communication structure, it is possible to exclude the effect of a wider range of communication obstacles.

4 is a diagram illustrating a second embodiment of the wireless optical communication based illumination system of FIG. 4 shows a first transmitting and receiving section 116-1 for transmitting and receiving light toward and from the communication section 114 of the adjacent illumination section 110 facing the communication section 114, Receiving section 117 that is spaced from the light emitting direction of the second transmitting and receiving section 116-2 by ± 15 degrees from the light emitting direction of the second transmitting and receiving section 116-2, As shown in Fig.

The first transmission / reception unit 116-1 and the second transmission / reception unit 116-2 may be all operated at the same time, but it may be efficient to be selectively operated according to the installation environment. In FIG. 4, An example in which the section 116-2 is selectively operated is shown.

The communication module 112 may further include an angle adjusting unit 118 for adjusting the light emitting direction of the communication unit such that the communication relay unit 120 is located in the overlapping area. According to such a configuration, it is possible to exclude the influence of a wide range of communication obstacles without adding a separate transmitting unit.

5 is a diagram illustrating a third embodiment of the wireless optical communication based illumination system of FIG. 5 shows an example in which the angle adjusting unit 118 adjusts the light radiation direction of the communication unit 112 such that the communication relay unit 120 is positioned in the overlapping area of the communication unit 116. [

5 shows an example in which the communication relay unit 120 is disposed on a fixed object in a position to bypass the communication obstacle 200 and the communication obstacle 200 It may be implemented as shown in FIG. 5 in a case where it is more effective to fix the communication relay unit 120 directly on the bypass route than to fix the communication relay unit 120 directly on the route.

The communication relay unit 120 may operate with a separate power supply, but it may be implemented to receive the intermediate power from a predetermined part of the neighboring lighting units 110. According to such a configuration, it is not necessary to provide a separate power supply for the communication relay unit 120.

The power supply may be implemented not only in a wired manner but also in a wireless manner, and the number and selection of the lighting unit 110 performing power supply may be variously modified depending on the installation mode.

FIG. 6 is a diagram showing a fourth embodiment of the wireless optical communication based illumination system of FIG. 1; 6 shows a wireless optical communication lighting system for transmitting control signals among a plurality of lighting groups each having a plurality of lighting devices each having a communication module for performing wireless communication and transmitting / receiving a lighting signal in a relay manner .

6 shows a first illumination group 1000, a second illumination group 2000 including an illumination device 110-2 adjacent to the illumination device 110-1 at the front or rear end of the first illumination group 1000, Respectively. 6 shows an example in which the light emitting regions of the illumination devices 110-1 and 110-2 adjacent to each other in the first illumination group 1000 and the second illumination group 2000 are arranged in an overlapping area, A communication relay unit 120 relaying communication between adjacent lighting apparatuses 110-1 and 110-2 communication modules is shown.

According to this configuration, since the communication relay unit is provided in a region where the light emitting regions of the communication modules provided respectively in the adjacent lighting apparatuses belonging to different lighting groups are overlapped, wireless communication can be performed between the lighting lamps belonging to different lighting groups, Even when an obstacle obstructing communication is located, it is possible to control the entire lighting lamp using the wireless optical communication.

7 is a schematic block diagram of a wireless optical communication based illumination system according to another embodiment of the present invention. 7, a communication module 212 is a communication module for an illumination system that wirelessly transmits / receives a lighting signal to / from adjacent lighting units 210 in a relay manner. The communication module 212 is a communication module that transmits / receives a lighting signal to / from an adjacent lighting unit 210 using a wireless optical communication A first communication unit 214-1, a second communication unit 214-2 that transmits and receives a lighting signal using predetermined radio-wave communication with other adjacent lighting units, and first and second communication units 214-1 and 214-2, And a signal conversion unit 218 for converting and transmitting the light signals received by the respective units.

In this manner, the communication module can communicate with the first communication unit 214-1 using the wireless optical communication as well as the second communication unit 214-2 using the radio communication with the first and second communication units 214-1 and 214-2 By including the signal conversion unit 218 for converting the reception signal, even when an obstacle obstructing the wireless communication is located between the illumination lights performing the wireless optical communication, the entire illumination light using the wireless communication can be controlled.

At this time, the predetermined radio wave communication is a communication using the radio wave of which the optical communication directivity of the optical communication carried out by the first communication unit is small, and may preferably be the Bluetooth communication.

FIG. 8 is a diagram illustrating an embodiment of the wireless optical communication based communication system of FIG. 7; FIG. 8, at least two illumination units 210-1 and 210-2 set in advance among a plurality of illumination units 210 are arranged with communication obstacles interposed therebetween and include the communication module 212 shown in FIG. 7 .

The communication module 212 includes a first communication unit 214-1 that transmits and receives a lighting signal using wireless optical communication with an adjacent lighting unit, a second communication unit 214 that transmits and receives a lighting signal by using Bluetooth communication with another adjacent lighting device -2), and a signal conversion unit 218 for converting and transmitting the lighting signals received by the first and second communication units 214-1 and 214-2, respectively.

At this time, the illumination unit excluding the predetermined illumination units 210-1 and 210-2 among the plurality of illumination units may include a communication module including only a communication unit that transmits and receives a lighting signal using the wireless optical communication. In addition, adjacent illumination units 210-1 and 210-2 located between the obstacles may belong to the same lighting group, but may belong to different lighting groups as shown in FIG.

Although the present invention has been described in terms of some preferred embodiments, the scope of the present invention should not be limited thereby but should be modified and improved in accordance with the above-described embodiments.

100, 200: Wireless optical communication based lighting system
110, 210:
112, 212: communication module
114, 214:
214-1: first communication section
214-2: second communication section
116: Transmitting /
118:
218:
120: communication relay unit
1000: First lighting group
2000: Second lighting group

Claims (17)

A plurality of illumination units each having a communication module for performing wireless optical communication and communicating with each other; And
And a communication relay unit for relaying communication between the communication modules in which the light emitting regions are overlapped, the communication relay unit being located in an overlapping region where the light emitting regions of the communication modules respectively provided in adjacent lighting units overlap,
Wherein the communication module includes a plurality of communication units each having a different light emission direction,
The communication unit includes a first transmitting and receiving unit for transmitting and receiving light toward and from a communication unit of an adjacent illumination unit facing each other, and a second transmitting and receiving unit in a light emitting direction spaced from a light emitting direction of the first transmitting and receiving unit by a predetermined angle, Including,
The communication relay unit,
Receiving portion is located at a position spaced apart from the light emitting direction of the first transmitting and receiving portion and within a predetermined radiation angle from the light emitting direction of the first transmitting and receiving portion when the size of the communication obstacle is smaller than the light emitting range of the first transmitting portion,
Wherein the communication obstacle is disposed at a position within the predetermined radiation angle from an optical radiation direction of the second transceiver when the size of the communication obstacle is larger than the optical radiation range of the first transmitter,
Wherein the first transmission / reception unit and the second transmission / reception unit selectively transmit a lighting signal to the same illumination unit according to the arrangement position of the communication relay unit.
The method according to claim 1,
Wherein the wireless optical communication is a wireless infrared communication.
delete delete delete The method according to claim 1,
Wherein the communication module further comprises an angle adjusting unit for adjusting an optical radiation direction of the communication unit such that the communication relay unit is located in the overlapping area.
The method according to claim 1,
Wherein the communication relay unit is disposed on a communication obstacle located between the adjacent illumination units.
The method according to claim 1,
Wherein the communication repeater is disposed on a fixture at a location that bypasses a communication obstacle located between the adjacent illumination units.
The method according to claim 1,
Wherein the communication relay unit receives power from a predetermined part of the adjacent illumination units.
There is provided a wireless optical communication lighting system of a plurality of lighting groups each having a plurality of lighting units each having a communication module for performing wireless optical communication and transmitting / receiving a lighting signal in a relay manner,
A first illumination group;
A second illumination group including an illumination unit adjacent to the illumination unit at the front end or the rear end of the first illumination group; And
And a communication relay unit relaying communication between the adjacent illumination unit communication modules, wherein the communication relay unit is disposed in an overlapping area in which the light emission areas of the illumination unit communication modules adjacent to each other in the first illumination group and the second illumination group overlap,
Wherein the communication module includes a plurality of communication units each having a different light emission direction,
The communication unit includes a first transmitting and receiving unit for transmitting and receiving light toward and from a communication unit of an adjacent illumination unit facing each other, and a second transmitting and receiving unit in a light emitting direction spaced from a light emitting direction of the first transmitting and receiving unit by a predetermined angle, Including,
The communication relay unit,
Receiving portion is located at a position spaced apart from the light emitting direction of the first transmitting and receiving portion and within a predetermined radiation angle from the light emitting direction of the first transmitting and receiving portion when the size of the communication obstacle is smaller than the light emitting range of the first transmitting portion,
Wherein the communication obstacle is disposed at a position within the predetermined radiation angle from an optical radiation direction of the second transceiver when the size of the communication obstacle is larger than the optical radiation range of the first transmitter,
Wherein the first transmission / reception unit and the second transmission / reception unit selectively transmit a lighting signal to the same illumination unit according to the arrangement position of the communication relay unit.
delete delete delete delete delete delete A wireless optical communication based illumination system for a plurality of illumination groups, each having a plurality of illumination units each having a communication module for performing wireless optical communication and transmitting / receiving a lighting signal in a relay manner,
A first illumination group; And
And a second illumination group including an illumination unit adjacent to the illumination unit at the front end or the rear end of the first illumination group,
The illumination unit of the first illumination group and the illumination unit of the second illumination group, which are adjacent to each other,
A first communication unit for transmitting and receiving a lighting signal using an adjacent lighting unit and a wireless optical communication;
A second communication unit for transmitting / receiving a lighting signal by using predetermined radio propagation communication with another adjacent lighting unit; And
And a communication module including a signal conversion unit for converting and transmitting the lighting signals received by the first and second communication units, respectively,
Wherein the wireless optical communication is a wireless infrared communication, the predetermined radio communication is a Bluetooth communication,
Wherein the signal conversion unit performs signal conversion so that the transmission form of the lighting signal is converted between the wireless infrared communication and the Bluetooth communication,
The communication module of the illumination unit of the first illumination group and the illumination unit of the second illumination group adjacent to each other are disposed with a predetermined communication obstacle therebetween to transmit and receive a lighting signal by using the Bluetooth communication,
Wherein the lighting unit of the first lighting group and the lighting unit of the second lighting group adjacent to each other among the plurality of lighting units transmits and receives the lighting signal using the wireless infrared communication.

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