U.S. patent application number 16/803011 was filed with the patent office on 2020-06-18 for method and apparatus for managing visible light communication devices.
The applicant listed for this patent is YUYANG DNU CO., LTD. Invention is credited to Sang Il CHOI, Byungoh KIM, Sangok KIM, Seok-joo KOH, Seung-wan ROH, Sang-ho YOON.
Application Number | 20200195345 16/803011 |
Document ID | / |
Family ID | 62195195 |
Filed Date | 2020-06-18 |
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United States Patent
Application |
20200195345 |
Kind Code |
A1 |
KIM; Sangok ; et
al. |
June 18, 2020 |
Method And Apparatus For Managing Visible Light Communication
Devices
Abstract
A visible light communication device management method and
apparatus are disclosed. According to one aspect of the present
disclosure, an object of the present disclosure is to provide an
apparatus and method for checking and managing a membership of a
terminal, such as a communication state and a location of a
terminal managed by the server.
Inventors: |
KIM; Sangok; (Seoul, KR)
; KIM; Byungoh; (Suwon-si, KR) ; YOON;
Sang-ho; (Suwon-si, KR) ; ROH; Seung-wan;
(Suwon-si, KR) ; KOH; Seok-joo; (Daegu, KR)
; CHOI; Sang Il; (Daegu, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
YUYANG DNU CO., LTD |
Hwaseong-si |
|
KR |
|
|
Family ID: |
62195195 |
Appl. No.: |
16/803011 |
Filed: |
February 27, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16463474 |
May 23, 2019 |
10615872 |
|
|
PCT/KR2017/013524 |
Nov 24, 2017 |
|
|
|
16803011 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B 10/1149 20130101;
H04B 10/1143 20130101; H04B 10/116 20130101 |
International
Class: |
H04B 10/116 20060101
H04B010/116; H04B 10/114 20060101 H04B010/114 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2016 |
KR |
10-2016-0157606 |
Claims
1. A method for use in a lighting device capable of visible light
communication, the method comprising: receiving a first formatted
message from a server; checking a header of the first formatted
message to identify whether the first formatted message is a first
management message; and in response to the first formatted message
being identified as the first management message, checking whether
or not at least one terminal previously located within illumination
coverage of the lighting device are still located within the
illumination coverage, wherein the checking whether or not
comprises: generating a second formatted message as a second
management message to be broadcast within the illumination
coverage; emitting visible light containing the second formatted
message; receiving a response message for the second management
message from at least one terminal, the response message including
a terminal identifier of an associated terminal; and updating a
management list based on the terminal identifier included in the
response message, the management list containing terminal
identifiers of terminals with which the lighting device can
communicate.
2. The method of claim 1, wherein the generating of the second
formatted message comprises copying some fields in the header of
the first formatted message into the header of the second formatted
message.
3. The method of claim 1, wherein the response message for the
second management message is received using wireless communication
different from the visible light communication.
4. The method of claim 1, wherein the updating of the management
list includes classifying the terminals into: a terminal included
in the management list and having transmitted the response message
for the second management message; a terminal included in the
management list but not having transmitted the response message for
the second management message; and a terminal not included in the
management list but having transmitted the response message for the
second management message.
5. The method of claim 4, further comprising: generates a response
message for the first management message, wherein the response
message for the first management message has a payload which
contains an identifier of the terminal included in the management
list but not having transmitted the response message for the second
management message and an identifier of the terminal not included
in the management list but having transmitted the response message
to the second management message; and transmitting the response
message for the first management message to the server.
6. A method for use in a lighting device capable of visible light
communication, the method comprising: receiving a first management
message from a server; and in response to the first management
message, checking whether or not at least one terminal previously
located within illumination coverage of the lighting device are
still located within the illumination coverage, wherein the
checking comprises: dividing a plurality of terminal identifiers
stored in a database managed by the lighting device into several
groups in accordance with predefined criteria given to a certain
digit of terminal identifier; generating a management list for each
group, the management list containing terminal identifiers that
meet respective predefined criterion; generating a second
management message that contains information on the respective
predefined criterion; emitting visible light containing the second
management message to broadcast within an illumination coverage of
the lighting device; receiving a response message for the second
management message from any terminal of which a terminal identifier
meets the respective predefined criterion, the response message
including an associated terminal identifier; and updating the
management list based on the response message for the second
management message.
7. The method of claim 6, wherein, the predefined criteria includes
whether a value of the certain digit of terminal identifier is
equal to a respective value assigned to each group.
8. The method of claim 6, wherein, the predefined criteria includes
whether a value of the certain digit of terminal identifier is odd
or even.
9. The method of claim 6, wherein, the predefined criterion
includes whether a remainder obtained by dividing the certain digit
of terminal identifier by the number of groups is equal to a
respective value assigned to each group.
10. The method of claim 6, wherein the updating of the management
list includes classifying the terminals into: a terminal included
in the management list and having transmitted the response message
for the second management message; a terminal included in the
management list but not having transmitted the response message for
the second management message; and a terminal not included in the
management list but having transmitted the response message for the
second management message.
11. The method of claim 10, further comprising: generates a
response message for the first management message, wherein the
response message for the first management message has a payload
which contains an identifier of the terminal included in the
management list but not having transmitted the response message to
the second management message and an identifier of the terminal not
included in the management list but having transmitted the response
message to the second management message; and transmitting the
response message to the first management message generated by the
data manager to the server.
12. The method of claim 6, wherein the response message for the
second management message is received using wireless communication
different from the visible light communication.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/463,474, which is the National Stage filing
of International Application No. PCT/KR2017/013524 on filed on Nov.
24, 2017, which claims priority under 35 U.S.C .sctn. 119(a) of
Patent Application No. 10-2016-0157606, filed on Nov. 24, 2016 in
Korea. The entire disclosures of each of the above applications are
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a method and apparatus for
managing visible light communication devices, in particular, a
lighting device and a terminal.
BACKGROUND
[0003] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0004] Visible light communication is wireless communication
technology for transmitting visible light data composed of an
on/off signal pattern based on the characteristics of fast response
of a lighting device. When visible light communication is applied
to a lighting device, the lighting device may transmit data to a
terminal through visible light communication.
[0005] The server manages the lighting device and the terminal, and
controls the lighting device to transmit data to all terminals
located within the visible light transmission coverage of the
lighting device. However, as various visible light communication
IoT services were developed, a technology has been developed to
control the server to transmit data only to a specific terminal,
not to all terminals, using a lighting device. In such cases, the
server needs to check the membership of the terminal, such as
whether the terminal is in a communicable state or whether the
terminal is continuously using the visible light communication IoT
service. If the terminal is a mobile device, it is necessary to
check if there is a need for the server to identify a lighting
device under which the terminal is arranged. There is a need for
the server to check whether the terminal is ready for communication
so as to inform the visible light communication IoT system
administrator of whether the terminal is out of service. Further,
when a specific terminal is a mobile device, there is a need for
the server to identify a lighting device under which the terminal
is arranged so as to determine a lighting device to which data to
be transmitted to the terminal is to be delivered.
SUMMARY
[0006] Therefore, it is one object of the present disclosure to
provide an apparatus and method for checking and managing
membership of a terminal managed by a server, such as a
communication state and the location of the terminal.
[0007] In accordance with one aspect of the present invention,
provided is a lighting device for checking state information about
one or more terminals used for visible light communication,
including a communication unit configured to receive a management
message to be transmitted to the one or more terminals from a
server and a response message to the management message from a
preset terminal, a data manager configured to divide the management
message into a header and a payload to check information indicating
control data for checking the state information included in the
header, include, in the header, information indicating a control
message for checking the state information so as to be transmitted
using visible light communication, and regenerate a management
message having a payload including information for instructing the
preset one of the one or more terminals to respond, a lighting unit
configured to modulate the regenerated management message into a
visible light signal and transmit the visible light signal to the
one or more terminals, a controller configured to generate a list
of the preset terminals and update the list of the preset terminals
by comparing the list of the preset terminals with the identifiers
of the terminals included in the response message to the management
message, and a database configured to store identifiers of the one
or more terminals and the list of the preset terminals.
[0008] As described above, according to one aspect of the present
disclosure, as the membership, such as the communication status and
the location of a terminal managed by a server, is checked and
managed, an administrator of a visible light communication IoT
service can easily manage the terminal.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a diagram illustrating a visible light
communication Internet of Things (IoT) system according to an
embodiment of the present disclosure.
[0010] FIG. 2 is a flowchart illustrating a process in which a
server manages terminals using a lighting device according to an
embodiment of the present disclosure.
[0011] FIG. 3 is a configuration diagram of a server according to
an embodiment of the present disclosure.
[0012] FIG. 4 is a diagram illustrating a configuration of data
transmitted and received between a server and a lighting device
according to an embodiment of the present disclosure.
[0013] FIG. 5 is a configuration diagram of a lighting device
according to an embodiment of the present disclosure.
[0014] FIG. 6 is a diagram illustrating a configuration of data
transmitted and received between a lighting device and a terminal
according to an embodiment of the present disclosure.
[0015] FIG. 7 is a configuration diagram of a terminal according to
an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0016] Hereinafter, some embodiments of the present disclosure will
be described in detail with reference to the accompanying drawings.
It should be noted that, in adding reference numerals to the
constituent elements in the respective drawings, like reference
numerals designate like elements, although the elements are shown
in different drawings. Further, in the following description of the
present disclosure, a detailed description of known functions and
configurations incorporated herein will be omitted when it may make
the subject matter of the present disclosure rather unclear.
[0017] Additionally, various terms such as first, second, A, B,
(a), (b), etc., are used solely for the purpose of differentiating
one component from the other but neither imply nor suggest the
substances, the order or sequence of the components. Throughout
this specification, when a part "includes" or "comprises" a
component, the part may further include other components, and such
other components are not excluded unless there is a particular
description contrary thereto. Terms such as "unit," "module," and
the like refer to units for processing at least one function or
operation, which may be implemented by hardware, software, or a
combination thereof.
[0018] FIG. 1 is a diagram illustrating a visible light
communication (VLC) Internet of Things (IoT) system according to an
embodiment of the present disclosure.
[0019] Referring to FIG. 1, a VLC IoT system 100 according to an
embodiment of the present disclosure includes a server 110, a
lighting device 120, and a terminal 130.
[0020] The server 110 is a management device of the VLC IoT system
that manages membership information about a terminal, such as
whether the terminal is ready for communication, whether the
terminal has moved, or when the provided visible light IoT service
is canceled.
[0021] The server 110 is connected to the lighting device 120 over
a wired or wireless network for a control operation. The wired
network includes wired communication using Ethernet communication,
a universal serial bus (USB), a wire, a twisted pair of wires, a
coaxial cable, an optical link, and the like. The wireless network
may include Bluetooth, Radio Frequency Identification (RFID),
Infrared Data Association (UDA), Ultra Ultra-Wide (UWB), ZigBee,
Digital Living Network Alliance (DLNA), Wireless LAN (WLAN), Wi-Fi,
Wireless Broadband (WiBro), World Interoperability for Microwave
Access (WIMAX), High Speed Downlink Packet Access (HSDPA), and Long
Term Evolution (LTE)/LTE-Advanced (LTE-A).
[0022] The server 110 is connected to the lighting device 120 via
an aggregator 115. The server transmits a management message to one
or more terminals capable of transmitting and receiving information
to and from the lighting device using visible light communication
and receives a response message for the management message, thereby
managing the membership of the terminals. The server 110 stores a
lighting device identifier such as an IP address of the lighting
device 120 to transmit data to the lighting device 120 and stores
identifiers of terminals to determine a terminal for which
membership is being managed. In addition, the server 110 manages
the membership of the terminals by transmitting a management
message to one or more terminals capable of transmitting and
receiving information to and from the lighting device using visible
light communication and receiving response messages for the
management message. The server 110 controls the lighting device to
transmit a management message to each terminal at a preset time or
periodically and checks, through the lighting device, whether or
not a response message for the management message is received from
the terminals, to manage the membership of the stored terminals.
Details will be described with reference to FIGS. 2 to 4.
[0023] The aggregator 115 is a device connected to one or more
lighting devices to transmit data received from the server 110 to a
lighting device or to collect data transmitted by the one or more
lighting devices and deliver the collected data at once or
sequentially. The aggregator 115 may be implemented as a separate
element between the server 110 and the lighting device 120, or may
be implemented as a module in the server 110 to perform the
above-described operation in the server 110.
[0024] The lighting device 120 is a device which transmits the data
received from the server 110 to a terminal using visible light
communication. The lighting device 120 generates a visible light
signal representing data to be transmitted to the terminal by
repeatedly turning on/off, and transmits the visible light signal
to the terminal. Since the lighting device 120 repeatedly turns
on/off at a speed unnoticeable by the human optic nerve system, the
lighting device may maintain the function of lighting while
transmitting data. The lighting device 120 may be implemented as a
light emitting diode (LED), but is not limited thereto. The
lighting device may be replaced with any device that emits visible
light, such as a fluorescent lamp or visible light laser.
[0025] The lighting device 120 has a wired or wireless
communication module to enable wired/wireless network
communication. The lighting device 120 includes a wired
communication module when the lighting device is configured to
transmit and receive data to and from the server 110 using wired
network communication, and includes a wireless communication module
when the lighting device is configured to use wireless network
communication. The lighting device 120 receives data or messages
from the terminal 130 using a wireless communication module. The
lighting device 120 may include both a wired communication module
and a wireless communication module, or include a wireless
communication module alone.
[0026] The lighting device 120 delivers data to a terminal using
light in the range of visible light wavelengths. The lighting
device 120 is connected to the server 110 over a wired/wireless
network as described above, and receives data having a form
transmittable from the server 110 over the wired/wireless network.
The lighting device 120 analyzes the received data to check the
type of control data, and generates data having a form
transmittable through visible light communication. The lighting
device 120 includes information that enables determination of the
type of control data in the data having a form transmittable
through visible light communication.
[0027] The lighting device 120 stores identifiers of terminals so
as to identify terminals located under the transmission coverage of
the visible light signal thereof or to manage the membership of the
terminals regarding, for example, determination of a terminal to
which a visible light communication IoT service is to be
provided.
[0028] The terminal 130 is a device that extracts data from the
visible light signal received from the lighting device 120. The
terminal 130 receives the visible light signal from the lighting
device 120 using a visible light reception module. The visible
light reception module may be implemented as a camera, a
photodiode, or the like, but is not limited thereto. Any module
capable of receiving visible light may be employed in place of the
visible light reception module. The terminal 130 may employ the
visible light reception module as a built-in module or an external
module. The terminal 130 receives data over a visible light signal
emitted from the lighting device 120. Upon receiving the data, the
terminal 130 analyzes the received data and recognizes that the
data is a management message for managing the membership of a
terminal. When the terminal 130 is a management target, the
terminal 130 transmits a response message to the lighting device
120. Here, the management target refers an object that should
transmit a response message in response to the management message
upon receiving the management message from the lighting device 120.
All terminals that receive the management message may be the
management targets, or only some of the terminals that receive the
management message may be the management targets.
[0029] The terminal 130 may be implemented as a smart device such
as a smartphone or a tablet, a notebook computer, a laptop, or a
personal digital assistant (PDA), but is not limited thereto. The
terminal 130 may be implemented as an IoT device that is equipped
with a sensor including a light receiving sensor and a
communication function and disposed in a variety of objects such as
a household appliance, a power outlet, an automobile, and the like,
and is capable of connecting to the Internet.
[0030] Here, the identifier of the lighting device 120 or the
identifier of the terminal 130 refers to information for
identifying each lighting device or terminal. As the identifier, a
unique production number assigned at the time of production of the
lighting device or the terminal may be used, or unique
identification information such as, for example, an IP address or a
MAC address on the network used by the lighting device or the
terminal may be used. The above-mentioned types of information are
merely an example of the identifier, and the identifier includes
any information by which each lighting device or terminal can be
identified.
[0031] FIG. 2 is a flowchart illustrating a process in which a
server manages terminals using a lighting device according to an
embodiment of the present disclosure.
[0032] The server 110 transmits a management message to the
lighting device 120 (S210). The server 110 generates a management
message including, in the header, information indicating a control
message for managing the membership of a terminal, and transmits
the management message to the lighting device 120.
[0033] The lighting device 120 generates a device-to-be-managed
list (S220). The lighting device 120 sets the device-to-be-managed
list by setting all or a part of the stored identifiers of the
terminals as management targets. For example, when a small number
of terminals is communicating with the lighting device 120, all the
terminals stored in the lighting device 120 may be set as
management targets. However, when the number of terminals
communicating with the lighting device 120 is greater than or equal
to a predetermined number, overhead may occur in the lighting
device 120 if responses to the management message are received from
the terminals at one time. Accordingly, the lighting device 120 may
set all the stored terminals or only a part of the stored terminals
as management targets depending on the number of stored terminals.
In the case where only a part of the stored terminals is set as
management targets, the lighting device 120 may set the other
terminals as management targets immediately or a preset time after
management of the terminals set as management targets is
terminated.
[0034] The lighting device 120 sets management targets using the
identifiers of the terminals. Only terminals having identifiers
satisfying a specific condition are set as management targets. For
example, the lighting device 120 may set terminals whose
identifiers have the last digit set to an odd number as management
targets, or may set terminals whose identifiers have the last digit
set to a specific number as management targets. Alternatively, in
order to classify the terminals into several groups, terminals
whose identifiers yield the same remainder when divided by a
specific number may be set as management targets. The lighting
device generates a device-to-be-managed list including the
identifiers of the terminals set as the management targets. By
generating the device-to-be-managed list, the lighting device 120
may clearly identify the terminals which the lighting device 120
has set as terminals to respond and terminals that have responded
among the set terminals.
[0035] The lighting device 120 transmits a management message to
the terminal 110 (S230). In transmitting the management message for
managing the membership of the terminal, the lighting device 120
may broadcast a visible light signal such that any terminal
including a specific terminal within the transmission coverage of
the visible light signal can receive and check the message.
[0036] The terminal 110 determines whether the terminal is a
management target (S240). In the case where the lighting device
generates a device-to-be-managed list in operation S220 and sets
only some of the terminals rather than all the terminals as the
management targets, the terminal 110 analyzes the management
message and determines whether the terminal itself is a management
target. In FIG. 2, it is assumed that terminals 130, 130-1 and
130-2 are all management targets in a situation where only some
terminals are set as management targets.
[0037] The lighting device 120 receives a response message to the
management message from terminals which are management targets
(S250). The lighting device 120 determines whether response
messages for the management message have been received from all
terminals which are management targets. There is a possibility that
failure occurs in communication between the terminals 130, 130-1
and 130-2 and the lighting device 120. There may be a situation in
which the terminal 130, 130-1, 130-2 moves and receives a visible
light signal from a lighting device different from the lighting
device with which the identifier of the terminal has been
registered. In the above-described situation, it is difficult for
the terminal to receive the management message or to transmit a
response message even if the terminal receives the management
message. Therefore, the lighting device 120 receives response
messages to the management message from terminals which are
management targets, and determines whether the response messages
have been received from all terminals which are management
targets.
[0038] The lighting device 120 updates the device-to-be-managed
list (S260). The lighting device 120 determines whether response
messages to the management message have been received from all the
terminals which are management targets through operation S250, and
updates the device-to-be-managed list according to the
determination. The lighting device 120 updates the
device-to-be-managed list by classifying the management target
terminals into terminals that have transmitted a response message
to the management message and terminals that have not transmitted a
response message. In addition, since the lighting device 120
broadcasts the management message at random, not only the terminals
pre-stored in the lighting device 120 but also other terminals can
receive the management message. Even a terminal that is not
pre-stored in the lighting device 120 may become a management
target depending on the identifier thereof. Thus, a terminal that
is not in the device-to-be-managed list generated in operation S220
but has transmitted a response message for the management message
is added to the device-to-be-managed list and it is explicitly
indicated that the terminal is a newly added terminal.
[0039] The lighting device 120 transmits a response message to the
management message to the server 110 (S270). The lighting device
120 transmits, to the server 110, a response message including the
identifiers of terminals that have not transmitted a response
message to the management message among the management target
terminals and an identifier of a terminal that is not
pre-registered with the lighting device but has transmitted a
response message to the management message. As the server 110
receives the response message to the management message from the
lighting device, the server 110 recognize a terminal is not capable
of communication or a terminal that has moved to a specific
lighting device from another lighting device.
[0040] FIG. 3 is a configuration diagram of a server according to
an embodiment of the present disclosure.
[0041] Referring to FIG. 3, a server 110 according to an embodiment
of the present disclosure includes a communication unit 310, a
database 320, a data generator 330, and a controller 340.
[0042] The communication unit 310 transmits a management message to
the lighting device 120 under control of the controller 340. The
communication unit 310 may be implemented as a wired communication
module or a wireless communication module depending on the type of
connection with the lighting device 120. The communication unit 310
transmits data generated by the data generator 330 to the lighting
device 120 by wire or wirelessly according to the implemented form
thereof.
[0043] The database 320 stores the identifiers of a lighting device
and the identifier of a terminal, and distinguishes each lighting
device and each terminal using the stored identifier of the
lighting device or the terminal. In order to receive specific
information or a specific service through visible light
communication, the lighting device and the terminal are
pre-registered with the server 110. The lighting device and the
terminal are registered by transmitting the identifiers thereof to
the server 110, and the server 110 stores the received identifiers
of the lighting device and the terminal in the database 320. The
database 320 stores the identifier of the terminal by matching the
identifier of the terminal with the identifier of the lighting
device. Since a specific terminal is positioned near a specific
lighting device and thus can receive data only from the specific
lighting device, the database 320 may store the identifier of the
terminal by matching the identifier of the terminal with the
identifier of the lighting device. When the server 110 receives the
identifier of the terminal together with the identifier of the
lighting device from the lighting device, the database 320 stores
the received identifiers of the terminal and the lighting device
together. When the server 110 receives the identifier of the
terminal directly from the terminal rather than from the lighting
device, the server 110 identifies the location information about
each of the terminal and the lighting device. The controller 340 of
the server 110 may receive the location information directly from
the terminal or identify the location of the terminal using the
properties (for example, the signal strength or the direction in
which the signal is received) of a signal transmitted and received
by the terminal and the server. The location information about the
lighting device may also be identified in a similar manner. Using
the identified location information about each of the terminal and
the lighting device, the database 320 may store the identifier of a
specific terminal by matching the identifier of the specific
terminal with the identifier of a lighting device located closest
to the specific terminal.
[0044] The data generator 330 generates a management message to be
transmitted to terminals, using the lighting device 120. The
management message will be described with reference to FIG. 4.
[0045] FIG. 4 is a diagram illustrating a configuration of data
transmitted and received between a server and a lighting device
according to an embodiment of the present disclosure.
[0046] A management message 400 includes a header 410 and a payload
430.
[0047] The header 410 of the management message includes a data
type field 412, a flag field 414, a target node field 416, a
lighting ID field 418, a device ID field 420, a service ID field
422, and a sequence number 424.
[0048] The data type field 412 is a field for checking the type of
data to be transmitted. The data type field 412 is used to
determine whether the type of data to be transmitted by the server
is control data for controlling a target node of the data or
information data for transferring information to the target node of
the data. For example, when the value of the data type field 412 is
0, the data type may be control data. When the value of the data
type field 412 is 1, the data type may be information data. The
server 110 transmits the management message to the lighting device
120 to control the lighting device to transmit the management
message to the terminal in order to check the membership of the
terminal. Therefore, an indication (e.g., 0) indicating control
data is specified in the data type field 412.
[0049] The flag field 414 is a field for checking what kind of
control is performed when the type of data to be transmitted is
control data. The flag field 414 indicates that data to be
transmitted corresponds to data for causing a target node to
perform a specific operation, data for changing the setting of the
target node, or a management message for checking and managing the
membership of the target node. For example, if the value of the
flag field 414 is 0, the data may be control data for changing the
setting of the lighting device 120 or the terminal 130. When the
value is 1, the data may be control data for causing the controller
130 to perform a specific operation. When the value is 2, the data
may be a management message for checking and managing the
membership of the target node. Since the management message
transmitted by the server 110 is a management message for checking
the membership of the terminal, an indication (e.g., 2) indicating
that the message is a management message for checking the
membership of the terminal is specified in the flag field 414.
[0050] The target node field 416 is a field that allows the server
to check the node which is the final destination position of the
data to be transmitted. The target node field 416 is used to
determine whether the data to be transmitted by the server is data
for the lighting device or data for the terminal 130. For example,
when the value of the target node field 416 is 0, the data may be
data to be transmitted to a lighting device. When the value of the
target node field 416 is 1, the data may be data to be transmitted
to a terminal. Since the server 110 should control the lighting
device to broadcast the management message, an indication (e.g., 0)
indicating that the lighting device is a target node is specified
in the target node field 416.
[0051] The lighting ID field 418 is a field for identifying a
lighting device to which the data is to be transmitted. When the
data to be transmitted by the server is data for a lighting device,
the lighting ID field 418 contains the identifier of the lighting
device corresponding to the destination of the data. On the other
hand, when the data to be transmitted by the server is data for the
terminal, the lighting ID field 418 contains the identifier of a
lighting device via which the data is to be transmitted to the
terminal.
[0052] The device ID field 420 is a field for identifying a
terminal to receive the data. When the data to be transmitted by
the server is data for a lighting device, the device ID field 420
has a preset meaningless value. When the data to be transmitted by
the server is data for a terminal, the device ID field 420 includes
an identifier of the terminal to receive the data. Since the
management message transmitted by the server 110 should be
delivered to all terminals within the transmission coverage of the
visible light signal of the lighting device, rather than to a
specific terminal, an indication for causing the lighting device
120 to broadcast a management message to all terminals is specified
by specifying a preset indication, for example, by setting all bits
in the terminal identifier field 420 to 1.
[0053] The service ID field 422 is a field for identifying a
service to be used by a terminal to receive the data. When the data
to be transmitted by the server is data for the terminal, the
service ID field 422 includes a stored service identifier along
with the identifier of the terminal. This field remains unused in
an embodiment of the present disclosure, and has a preset
meaningless value.
[0054] The sequence number field 424 is a field that allows the
server to identify each of the data to be transmitted. Typically,
the server 110 transmits and receives a lot of data to and from a
specific terminal. Accordingly, the server 110 needs to distinguish
which of the response data received from the terminal is response
data corresponding to specific data transmitted to the terminal.
The sequence number field 424 is a field for identifying the
sequence number. If the sequence number of the data transmitted by
the server to the terminal matches the sequence number of the
response data transmitted to the server by the terminal, it may be
determined that the response data is a response to specific data
transmitted to the terminal by the server. On the other hand, when
the sequence numbers do not match, it may be determined that both
data are irrelevant to each other.
[0055] The data transmitted by the server 110 to the lighting
device 120 for membership management has the same header 410 of the
management message 400 as the data transmitted from the lighting
device 120 to the server 110 to inform the server 110 of the
membership after membership management. Since both the data
transmitted from the server 110 to the lighting device 120 and the
data transmitted from the lighting device 120 to the server 110 are
data for management of membership of the terminal, both data have
the same value of each field in the header of the management
message. However, the payload of the data transmitted from the
server 110 to the lighting device 120 for membership management
includes information necessary for the lighting device to operate
according to the management message, while the payload of the data
transmitted from the lighting device 120 to the server 110 includes
membership status information about the terminal. The membership
status information about the terminal in the payload of the data
transmitted from the lighting device 120 to the server 110 will be
described later.
[0056] The data generator 330 includes information necessary for
the lighting device to operate according to the management message
in the payload 430 of the management message.
[0057] The data generator 330 includes the header 410 and the
payload 430 of the management message in a header or a payload of
data of the physical layer, which is the lowest layer in the OSI
model, or a higher layer thereof to generate data of the physical
layer or the higher layer thereof. The data generator 330 generates
data of the physical layer or the higher layer including a
management message in the header or the payload such that the
communication unit 310 can transmit the management message to the
lighting device 120.
[0058] The controller 340 controls the lighting device to transmit
the management message to the lighting device 120 at a preset time
or periodically. The controller 340 includes a timer (not shown)
and thus controls the data generator 330 to generate a management
message at a preset time or periodically. In addition, when the
management message is generated, the controller 340 controls the
communication unit 310 to transmit the management message to the
lighting device 120 having the lighting ID included in the
management message.
[0059] FIG. 5 is a configuration diagram of a lighting device
according to an embodiment of the present disclosure.
[0060] Referring to FIG. 5, the lighting device 120 according to an
embodiment of the present disclosure includes a communication unit
510, a data manager 520, a controller 530, a flash memory 540, and
a lighting unit 550.
[0061] The communication unit 510 is connected to the server 110
using a wired/wireless communication module and receives a
management message from the server 110. The communication unit 510
receives a response message to the management message from the
terminal 130 using the wireless communication module. Also, the
communication unit 510 transmits the response message regenerated
by the data manager 520 in response to the management message to
the server 110.
[0062] The data manager 520 analyzes the received management
message and generates data that the lighting unit 550 can transmit
to the terminal using visible light communication. The data manager
520 analyzes the received management message and distinguishes
between the header and the payload of the management message. When
recognizing that the data received from the server 110 is a
management message, the data manager 520 generates management data
that the lighting unit 550 can transmit to the terminal 130 using
visible light communication. Details will be described with
reference to FIG. 6.
[0063] FIG. 6 is a diagram illustrating a configuration of data
transmitted and received between a lighting device and a terminal
according to an embodiment of the present disclosure.
[0064] A management message 600 to be transmitted to the terminal
130 using visible light communication or a response message 600 to
be transmitted to the lighting device 120 by the terminal 130 in
response to the received management message includes a header 610
and a payload 620. The management message or the response message
has the same header 610 and the same payload 620 as the management
message or the response message is a message for management of the
membership of the terminal 130.
[0065] The data manager 520 generates the management message 600
including only necessary fields of the header 410 of the management
message 400 in the header 610.
[0066] The data manager 520 includes the data type field 412 of the
management message 400 in the data header of the management message
600. The data manager 520 includes the data type field 412 of the
management message 400 such that the terminal receiving the data
can recognize that the data is control data.
[0067] The data manager 520 includes the flag field 414 of the
header 410 of the management message 400 in the data header of the
management message 600. Based on the flag field 420, the terminal
130 may check the kind of the control data transmitted thereto.
[0068] The data manager 520 includes the lighting ID field 418 of
the header 410 of the management message 400 in the data header of
the management message 600. When the terminal 130 receives data
from the lighting device 120, the source that transmitted the data
is identified from the lighting ID field 418. In addition, when
terminal 130 transmits response data for the received data, the
lighting device ID may be used for a destination to receive the
response data.
[0069] The data manager 520 includes the device ID field 420 of the
header 410 of the management message 400 in the data header of the
management message 600. Based on the device ID field 420, the
terminal 130 may recognize that the management data is broadcast
from the lighting device 120. When the terminal 130 recognizes that
the management data is broadcast using the device ID field 420, the
terminal 130 determines whether the terminal 130 is a management
target by checking the payload 620 in the management message
600.
[0070] The data manager 520 includes the sequence number field 424
of the header 410 of the management message 400 in the data header
of the management message 600. Using the sequence number field 424,
the terminal 130 identifies the received data and the data for
which response data is provided later.
[0071] The data manager 520 includes the data included in the
payload 420 of the management message 400 in the payload 620 of the
management message 600. In addition, the data manager 520 includes,
in the payload 620, an offset value generated by the controller
530, or the offset value and a group number value generated by the
controller 530.
[0072] The data manager 520 generates data of the physical layer or
the higher layer thereof by including the header 610 and the
payload 630 of the management message 600 in the header or payload
of the data of the physical layer or the higher layer in the OSI
model. The data manager 520 generates the data of the physical
layer or the higher layer thereof so as to have a protocol that
enables visible light communication (VLC). That is, the data
manager 520 regenerates the data received by the communication unit
510 from the server 110 using the wired or wireless communication
such that the lighting unit 550 can transmit the data using
VLC.
[0073] In addition, the data manager 520 analyzes the response
message received from the terminal 130, and recognizes the
identifier of the terminal included in the response message. By
recognizing the identifier of the terminal included in the response
message, the data manager 520 may identify the terminal that has
transmitted the response message.
[0074] Under control of the controller 530, the data manager 520
regenerates a response message including the identifier of a
terminal which is a management target but has not transmitted a
response message, and the identifier of a terminal that is not a
management target but has transmitted a response message in the
payload in response to the management message. As described above,
the data manager 520 has the same header as that of the management
message received from the server 110, and regenerates a response
message including the identifier of the above-mentioned terminal in
the payload.
[0075] Upon recognizing that the management message 400 is received
from the server 110 according to the analysis of the data manager
520, the controller 530 sets management targets to generate a
device-to-be-managed list. As described above, the controller 530
may set all terminals stored in the flash memory 540 as management
targets, or may set only a part of the terminals stored in the
flash memory 540 as management targets in some cases. In the case
where only some of the stored terminals are set as management
targets, the lighting device 120 may set the other terminals as
management targets immediately or a preset time after management of
the terminals set as management targets is terminated. When setting
a terminal to transmit a response message, the controller 530 sets
an offset value, or an offset value and a group number value. The
controller 530 sets a terminal that is to transmit the response
message using an identifier. The controller 530 may set only a
terminal whose identifier has the last digit matching the offset
value as a terminal to transmit a response message. Alternatively,
the controller 530 may set the number of groups into which the
terminals 130 are divided, and set only terminals whose identifiers
yield the remainder matching the offset value when divided by the
number of divided groups, as terminals to transmit the response
message. For example, when the terminals are divided into n groups,
the group number value is n and the offset value is 0 to n-1. The
terminal divides the identifier thereof by n, identifies the
remainder, and checks whether the remainder is among the offset
values to determine whether the terminal is an object to transmit a
response message (a management target). The controller 530
generates a device-to-be-managed list with the management targets
set by the above-described method. By generating the
device-to-be-managed list, the controller 530 may identify which of
the terminals set to transmit a response message transmitted has
transmitted the response message and which terminal has not
transmitted the response message. After generating the
device-to-be-managed list, the controller 530 controls the data
manager 520 to include the set offset value, or the offset value
and group number value in the payload 620 of the management message
600.
[0076] The controller 530 identifies which terminals have
transmitted the response message for the management message
according to the analysis of the data manager 520. The terminals
having transmitted the response message may include a terminal
classified as a management target and a terminal not classified as
a management target. The terminal not classified as a management
target transmits a response message for the following reason. The
device-to-be-managed list is merely a list generated by the
lighting device 120 to manage the membership of the terminals and
the management message is substantially broadcast to all terminals
within the transmission coverage of the visible light signal of the
lighting device 120. That is, all terminals may receive the
management message. When a terminal corresponds to a management
target according to the identifier thereof, the terminal transmits
a response message to the management message. The controller 530
compares the identifier of the terminal included in the response
message with the device-to-be-managed list, thereby identifying
terminals that have transmitted the response message among the
management targets, terminals that have not transmitted the
response message among the management targets, and terminals which
are not management targets but have transmitted the response
message. The controller 530 controls the data manager 520 to
include, in the payload of the response message to the management
message 600, the identifiers of terminals that have not transmitted
the response message among the management targets and the
identifiers of terminals which are not management targets but have
transmitted the response message. As the identifiers of the
corresponding terminals are included in the payload, the server 110
may check the membership information about the terminals, such as
whether communication is impossible or whether the terminal is
moved from a specific light to another light.
[0077] The flash memory 540 stores identifiers of terminals capable
of transmitting data thereto using wireless communication and the
device-to-be-managed list generated by the controller 530.
[0078] The lighting unit 550 modulates the management message 600
generated by the data manager 520 into a visible light signal and
transmits the visible light signal to all terminals within the
transmission coverage of the visible light signal.
[0079] FIG. 7 is a configuration diagram of a terminal according to
an embodiment of the present disclosure.
[0080] Referring to FIG. 7, the terminal 130 according to an
embodiment of the present disclosure includes a visible light
receiver 710, a data manager 720, a controller 730, and a
communication unit 740.
[0081] The visible light receiver 710 receives a management message
from the lighting device 120. The visible light receiver 710 may be
implemented as a built-in or external camera or a visible light
reception module in the terminal 130, and may receive a management
message transmitted over a visible light signal.
[0082] The data manager 720 analyzes the received visible light
signal, determines that the signal is a management message, and
checks an offset value, or the offset value and a group number
value included in the management message.
[0083] By checking the offset value, or the offset value and the
group number value included in the management message analyzed by
the data manager 720, the controller 730 determines whether the
terminal 130 is a management target. As described above, the
controller 730 determines whether the terminal 130 is a management
target by determining whether the last digit of the identifier of
the terminal matches the offset, or whether the identifier of the
terminal divided by the group number value yields a remainder equal
to the offset. When determining that the terminal is a management
target, the controller 730 controls the communication unit 740 to
transmit the received management message as a response message to
the lighting device 120 without generating a separate message. On
the other hand, when the controller 730 determines that the
terminal is not a management target, it does not take any other
action.
[0084] The communication unit 740 transmits the response message to
the lighting device 120.
[0085] Although exemplary embodiments of the present disclosure
have been described for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the spirit and
scope of the appended claims. Therefore, the present disclosure is
to be construed as illustrative rather than limiting, and the scope
of the present disclosure is not limited by the embodiments. The
scope of protection of the disclosure should be construed according
to the appended claims, and all technical ideas within the scope of
the claims and equivalents thereto should be construed as being
within the scope of the disclosure.
DESCRIPTION OF REFERENCE NUMERALS
TABLE-US-00001 [0086] 100: VLC IoT system 110: Server 120: Lighting
device 130: Terminal 310, 510, 740: Communication unit 320:
Database 330: Data generator 340, 530, 730: Controller 400, 600:
Management message 410, 610: Header 412: Data type field 414: Flag
field 416: Target node field 418: Lighting ID field 420: Device ID
field 422: Service ID field 424: Sequence number field 430, 620:
Payload 520, 720: Data manager 540: Flash memory 550: Lighting unit
710: Visible light receiver
* * * * *