CA-2984887-C - METHOD FOR CHANGING THE IDENTIFICATION CODE OF A LIGHT SOURCE IN VISIBLE LIGHT COMMUNICATION SYSTEMS

Abstract

The invention relates to a method for changing the identification code of a light source in a visible light communication system, which visible light communication system comprises the light source, a driver system to drive the light source, and a server that is not able to communicate directly with the driver system, and which method makes use of a first mobile device comprising an image sensor, a processing unit, a network adapter, and a transmitter, wherein the processing unit is configured to process an output of the image sensor, wherein the processing unit is configured to communicate with the server via the network adapter, and wherein the processing unit is configured to send signals to the driver system using the transmitter, said method comprising the following steps: a.receiving a signal from the server by the network adapter of the first mobile device, said signal comprising a command to change the identification code of the light source from a first ID code to a second ID code; and b.transmitting, by the transmitter of the first mobile device, a signal to the driver system, said signal comprising a command to change the identification code of the light source to a second ID code.

Inventors

• Marc Saes
• Stephen Haight Lydecker

Assignees

• ELDOLAB HOLDING B.V.

Dates

Publication Date

20260505

Application Date

20160503

Priority Date

20150507

Claims (1)

1. CLAIMS 1. A method for changing an identification code of a light source in a visible light communication system, which visible light communication system comprises the light source, a driver system to drive the light source, and a server that is not able to communicate directly with the driver system, and which method makes use of a first mobile device comprising an image sensor, a processing unit, a network adapter, and a transmitter, wherein the processing unit is configured to process an output of the image sensor, wherein the processing unit is configured to communicate with the server via the network adapter, and wherein the processing unit is configured to send signals to the driver system using the transmitter, said method comprising the following steps: a. determining by the server that the identification code of the light source is to change from a first ID code to a second ID code and transmitting by the server, in response to the determination, a first signal to the network adapter of the first mobile device, said first signal comprising a command to change the identification code of the light source from the first ID code to the second ID code; b. receiving the first signal from the server by the network adapter ofthe first mobile device, said first signal comprising the command to change the identification code of the light source from the first ID code to the second ID code; and c. transmitting, by the transmitter of the first mobile device, a second signal to the driver system, said second signal comprising a command to change the identification code of the light source to the second ID code, after the network adapter of the first mobile device receives from the server the first signal comprising the command to change the identification code of the light source from the first ID code to the second ID code. 13 Date Re~iue/Date Received 2024-05-28 2. A method according to claim 1, further comprising the following steps: d. receiving a confirmation signal from the driver system that the identification code of the light source successfully has been changed to the second ID code; and e. transmitting a confirmation signal to the server that the identification code of the light source successfully has been changed to the second ID code. 3. A method according to claim 2, wherein the confirmation signal in step d. is received by the first mobile device, and wherein transmitting the confirmation signal to the server in step e. is carried out by the network adapter of the first mobile device. 4. A method according to claim 2, wherein use is made of a second mobile device comprising an image sensor, a processing unit, a network adapter, and a transmitter, wherein the processing unit is configured to process an output of the image sensor, wherein the processing unit is configured to communicate with the server via the network adapter, and wherein the processing unit is configured to send signals to the driver system using the transmitter, wherein the confirmation signal in step d. is received by the second mobile device, and wherein transmitting the confirmation signal to the server in step d. is carried out by the network adapter of the second mobile device. 5. A driver system configured to drive a light source, the driversystem comprising: a control unit; and a light driver, Date Re~iue/Date Received 2024-05-28 14 wherein the light driver is configured to convert energy provided by a power source into a form suitable for the light source, and wherein the control unit is configured to control the light driver such that the light source emits modulated light comprising at least an identification code, wherein the driver system further comprises a receiver to receive signals from nearby mobile devices, and in that the control unit is further configured to change the identification code from a first ID code to a second ID code upon receiving from one of the mobile devices a second signal by the receiver of the driver system, said second signal comprising a command to change the identification code of the light source, the command being received by the driver system in response to determining by a server that the identification code of the light source is to change from the first ID code to the second ID code and transmitting by the server, in response to the determination, a first signal to the mobile devices, said first signal comprising the command to change the identification code of the light source. 6. A driver system according to claim 5, wherein the control unit is further configured to transmit a confirmation signal using modulation of the light source after successfully changing the identification code of the light source. 7. A visible light communication system comprising: - a light source; - a driver system; - a server; and - a mobile device, wherein the driver system is configured to drive the light source such that the light source emits a modulated light comprising at least an identification code associated with the light source, Date Re~iue/Date Received 2024-05-28 wherein the mobile device is configured to receive the identification code from the light source to identify the light source, and wherein the server is configured to allow the mobile device to identify the light source, wherein the server is further configured to initiate a change of the identification code of the light source by sending a first signal comprising a corresponding command to the mobile device, and to update the identification code of the light source upon receiving a confirmation of the change from the mobile device, in that the mobile device is further configured to receive from the server said first signal comprising said command to change the identification code of the light source, to relay to the driver system the command to change the identification code of the light source by sending a second signal comprising the command to change the identification code of the light source, after a network adapter of the first mobile device receives from the server the first signal comprising the command to change the identification code of the light source, to receive a confirmation of the change from the driver system, and to relay the confirmation to the server, and in that the driver system is further configured to receive said second signal comprising said command to change the identification code of the light source from the mobile device, to change the identification code accordingly, and to send the confirmation thereof to the mobile device. 8. A visible light communication system comprising: a light source; a driver system; a server; and a mobile device, Date Re~iue/Date Received 2024-05-28 16 wherein the driver system is configured to drive the light source such that the light source emits a modulated light comprising at least an identification code associated with the light source, wherein the mobile device is configured to receive the identification code from the light source to identify the light source, and wherein the server is configured to allow the mobile device to identify the light source, wherein the driver system comprises a rolling code sequence of different identification codes and a time table indicating when to change the identification code of the light source to a next identification code in the rolling code sequence, wherein the server comprises the same rolling code sequence of different identification codes and time table as stored in the driver system, and wherein the server and driver system are synchronized via the mobile device to simultaneously change the identification code of the light source according to the rolling code sequence of different identification codes and the time table, wherein the first mobile device is configured to identify the light source by means of the synchronized identification code, and use information relating to identification of the light source for interaction with a user of the first mobile device. 9. The method according to any one of claims 1 - 4, wherein the server transmits in step a the first signal comprising the command to change the identification code of the light source from the first ID code to the second ID code to at least two mobile devices, wherein a first one of the mobile devices that establishes a connection with the light source after receiving the first signal comprising the command to change the identification code of the light source from the first ID code to the second ID code, is the first mobile device that transmits to the light 17 Date Re~iue/Date Received 2024-05-28 source the second signal comprising the command to change the identification code of the light source from the first ID code to the second ID code. 10. The method according to claim 9, wherein the mobile devices are mobile user devices, such as a smartphone or a tablet, of users that may move through a space illuminated by the light source. 11. The method according to any one of claims 1 - 4, wherein information relating to the light source and a coupling between the second ID code and the light source are stored on the server, wherein the information relating to the light source is sent by the server to the first mobile device, and wherein, in response to the first mobile device receiving the second ID code from the light source, the light source is identified by means of the second ID code, and the information relating to the light source is used by the first mobile device for interaction with the user of the first mobile device. 12. The method according to claim 11, wherein the information relating to the light source and associated with the second ID code is sent by the server to the first mobile device in response to the first mobile device receiving, from the light source, the second ID code and the first mobile device requesting the server to send the information relating to the light source and associated with the second ID code. 13. The method according to claim 11, wherein the information relating to the light source and associated with the second ID code is loaded by the server into the first mobile device, prior to the first mobile device receiving, from the light source, the second ID code. 14. The visible light communication system according to claim 7, wherein the server is configured to send the first signal comprising the command to change the identification code of the light source from the first ID code to the second 18 Date Re~iue/Date Received 2024-05-28 ID code to at least two mobile devices, wherein a first one of the mobile devices that establishes a connection with the light source after receiving the first signal comprising the command to change the identification code of the light source from the first ID code to the second ID code, is the first mobile device that transmits to the light source the second signal comprising the command to change the identification code of the light source from the first ID code to the second ID code. 15. The visible light communication system according to claim 14, wherein the mobile devices are mobile user devices, such as a smartphone or a tablet, of users that may move through a space illuminated by the light source. 16. The visible light communication system according to claim 7, wherein information relating to the light source and a coupling between the second ID code and the light source are stored on the server, wherein the server is configured to send the information relating to the light source to the first mobile device, and wherein the first mobile device is configured to, in response to the first mobile device receiving the second ID code from the light source, identify the light source by means of the second ID code, and use the information relating to the light source for interaction with the user of the first mobile device. 17. The visible light communication system according to claim 16, wherein the server is configured to send the information relating to the light source and associated with the second ID code to the first mobile device in response tothe first mobile device receiving, from the light source, the second ID code and the first mobile device requesting the server to send the information relating to the light source and associated with the second ID code. 19 Date Re~iue/Date Received 2024-05-28 18. The visible light communication system according to claim 16, wherein server is configured to load the information relating to the light source and associated with the second ID code into the first mobile device, prior to the first mobile device receiving, from the light source, the second ID code. 19. The method according to any one of claims 1 - 4 and 9 - 13, wherein the identification code is modulated onto light emitted by the light source.

Description

Title: Method for changing the identification code of a light source in visible light communication systems The invention relates to a method for changing the identification code of a light source in visible light communication systems. Light sources are used everywhere to produce light. Examples are indoor/outdoor lamps, 1 0 TVs, traffic signs, commercial displays, car headlights/taillights, etc. A code, i.e. digital information, may be incorporated into the emitted light by modulating the light source, i.e. turning them on and off. This principle may be referred to as Visible Light Communication or VLC. When the modulation is fast enough, i.e. turning the light source on and off is done rapidly, the incorporation of digital information into the emitted light is unperceivable to the 15 human eye. Hence, VLC uses the phenomenon that if a frequency of an intermittent light stimulus is above a so-called flicker fusion threshold, the intermittent light stimulus appears to be completely steady to the average human observer. In some cases it may also be important that the modulation is unperceivable for a technical 20 observer, such as a television studio camera. The digital information may be incorporated into the emitted light using different types of modulation, for instance amplitude modulation, in which the intensity is varied, frequency modulation, in which the frequency is varied, and phase modulation, in which the signal is 25 shifted in time with respect to some reference clock. The transmitted code in the modulated light may comprise an identification code which can e.g. be used to determine the position of a mobile device in a store. The mobile device therefore comprises an image sensor receiving the modulated light and a processing unit to 30 obtain the identification code from the received signal. The identification code can be used to determine the position of the mobile device in order to provide position dependent content to the user of the mobile device or for navigating through a store. The information to determine the position of the mobile device and the position dependent 35 content may be preloaded onto the mobile device or may be available via a remote server communicating with the mobile device. In both situations, communication with the remote server is required, either because the information is preloaded from the server onto the 1 mobile device (and preferably regularly updated) or because the information is only available through communication with the server. When a static identification code for the light source is used as is for instance disclosed in 5 US patent publication US2013/0029682 A 1, the identification code may be obtained by third parties, which subsequently can use the identification code for their own applications. Such use of the light sources and corresponding identification codes may be undesired and rolling codes may be used as a security measure. When using rolling codes, the identification code of the light source is changed regularly, so that it is more difficult for third parties to use the 10 identification codes of the light sources for their own applications as they have to keep up with the changes in identification codes, which is even more difficult when the number of light sources involved increases. However, when using rolling codes it is important that both the server and the light source 15 use the same code at the same time for flawless operation. However, in situations in which there is no direct communication between the light source and the server, rolling codes cannot be used as the light source and server are not able to synchronize the change of identification code. 20 Hence, it is an object of the invention to provide a VLC system in which it is more difficult for third parties to use the identification codes transmitted by light sources for their own purposes. According to a first aspect of the invention, there is provided a method for changing the 25 identification code of a light source in a visible light communication system, which visible light communication system comprises the light source, a driver system to drive the light source, and a server that is not able to communicate directly with the driver system, and which method makes use of a first mobile device comprising an image sensor, a processing unit, a network adapter, and a transmitter, wherein the processing unit is configured to 30 process an output of the image sensor, wherein the processing unit is configured to communicate with the server via the network adapter, and wherein the processing unit is configured to send signals to the driver system using the transmitter, said method comprising the following steps: a. receiving a signal from the server by the network adapter of the mobile device, said 35 signal comprising a command to change the identification code of the light source from a first ID code to a second ID code; and 2 b. transmitting, by the transmitter of the mobile