APPARATUS AND METHOD FOR SUPPORTING MOBILITY OF A MOBILE TERMINAL THAT PERFORMS VISIBLE LIGHT COMMUNICATION

• US 20120008959A1
• Filed: 09/15/2011
• Published: 01/12/2012
• Est. Priority Date: 09/19/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: SON, Jae-Seung, Kim, Do-Young, Won, Eun-Tae, Bae, Tae-Han, Cho, Young-Kwon, Gu, Sun-Gi
• Granted Patent: US 8,792,790 B2
• Time in Patent Office: Days
• US Class Current: 398/99
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/116 Visible light communication

Abstract

A method and apparatus for supporting mobility of a mobile terminal in a Visible Light Communication (VLC) system. The method includes searching, by the VLC device, for a first mobile terminal in a plurality of cells; locating the first mobile terminal in a first cell among the plurality of cells; exchanging data with the first mobile using a light source of the first cell; determining whether a response signal corresponding to data reception is received from the first mobile terminal in the first cell; searching for the first mobile terminal in a neighboring cell of the first cell, if the response signal is not received; and determining the neighboring cell as a second cell for visible light activation, if the first mobile terminal is located in the neighboring cell.

Claims

1. A method for supporting, by a Visible Light Communication (VLC) device, mobility of a mobile terminal that performs VLC with the VLC device, the method comprising:

searching, by the VLC device, for a first mobile terminal in a plurality of cells;

locating the first mobile terminal in a first cell among the plurality of cells;

exchanging data with the first mobile using a light source of the first cell;

determining whether a response signal corresponding to data reception is received from the first mobile terminal in the first cell;

searching for the first mobile terminal in a neighboring cell of the first cell, if the response signal is not received; and

determining the neighboring cell as a second cell for visible light activation, if the first mobile terminal is located in the neighboring cell.

2. The method of claim 1, wherein searching for the first mobile terminal comprises performing a discovery operation by transmitting a beacon signal.

3. The method of claim 1, further comprising:

performing link negotiation and link connection with the first mobile terminal, after locating the first mobile terminal.

4. The method of claim 1, wherein each of the plurality of cells is capable of performing visible light communication using a predetermined number of light sources.

5. The method of claim 1, wherein the response signal includes one of an Acknowledgement frame signal and a Color Visible Dimming (CVD) frame.

6. The method of claim 1, further comprising:

counting a number of failures for receiving the response signal, if the first mobile terminal is not found in the neighboring cell,; and

changing a search cell to a new neighboring cell and searching for the first mobile terminal in the new neighboring cell, if the number of failures exceeds a predetermined threshold.

7. The method of claim 1, further comprising:

locating a second mobile terminal other than the first mobile terminal; and

setting visible light active regions separately with respect to the first mobile terminal and the second mobile terminal.

8. The method of claim 7, further comprising managing the first mobile terminal and the second mobile terminal using a Time Division Multiple Access (TDMA) scheme.

9. The method of claim 1, wherein the VLC device includes an Access Point (AP).

10. A Visible Light Communication (VLC) apparatus for providing mobile VLC with a mobile terminal, the apparatus comprising:

a light source manager for managing information about each of a plurality of light sources and determining a cell to be activated for VLC among a plurality of cells, each of the plurality of cells including a predetermined number of the plurality of light sources;

a light source controller for providing a VLC function to light sources of the determined cell; and

a controller for searching for a first mobile terminal in the plurality of cells, exchanging data with the first mobile using a first cell among the plurality of cells in which the first mobile terminal is found, determining whether a response signal corresponding to data reception is received from the first mobile terminal in the first cell, searching for the first mobile terminal in a neighboring cell of the first cell, if the response signal is not received, and determining the neighboring cell as a second cell for visible light activation, if the first mobile terminal is found in the neighboring cell.

11. The apparatus of claim 10, wherein the controller performs a discovery operation by transmitting a beacon signal.

12. The apparatus of claim 11, wherein the controller performs link negotiation and link connection with the first mobile terminal, after locating the first mobile terminal.

13. The apparatus of claim 10, wherein the response signal comprises one of:

an Acknowledgement frame signal; and

a Color Visible Dimming (CVD) frame.

14. The apparatus of claim 10, wherein the controller counts a number of failures for receiving the response signal, if the first mobile terminal is not found in the neighboring cell, and changes a search cell to a new neighboring cell and searches for the first mobile terminal in the new neighboring cell, if the counted number of failures exceeds a predetermined threshold.

15. The apparatus of claim 10, wherein the controller locates a second mobile terminal other than the first mobile terminal, and sets visible light active regions separately with respect to the first mobile terminal and the second mobile terminal.

16. The apparatus of claim 15, wherein the controller manages the first mobile terminal and the second mobile terminal using a Time Division Multiple Access (TDMA) scheme.

17. The apparatus of claim 10, wherein the VLC apparatus comprises an Access Point (AP).