VISIBLE LIGHT COMMUNICATION METHOD AND SYSTEM

• US 20100209105A1
• Filed: 02/17/2010
• Published: 08/19/2010
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Jeong-Seok, Lee, Kyung-Woo, Shin, Hong-Seok, Cho, Jae-Hun, Jung, Dae-Kwang, Park, Sung-Bum
• Granted Patent: US 8,452,188 B2
• Time in Patent Office: Days
• US Class Current: 398/58
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access
• CPC Class Codes: H05B 47/195 the transmission using visible or infrared light

Abstract

A Visible Light Communication (VLC) method in a VLC terminal, in which the VLC terminal requests initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame, sends an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame, and transmits data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot.

Claims

1. A Visible Light Communication (VLC) method in a VLC terminal, comprising:

requesting initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame;

sending an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame; and

transmitting data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot.

2. The VLC method of claim 1, further comprising re-performing the initial access request if the uplink time slot allocated to correspond to the selected mini-slot does not exist in the control information in the frame.

3. The VLC method of claim 1, further comprising re-performing the association request if there is no response to the association request within an association wait time after the association request.

4. The VLC method of claim 1, wherein requesting initial access comprises:

determining a position of the control slot in the frame and a number of mini-slots constituting the control slot by analyzing the control information in the frame;

selecting a backoff timer value;

selecting a mini-slot in a frame having a backoff timer value of zero (0) by decreasing the backoff timer value by one on a frame basis; and

requesting initial access by transmitting a control symbol on the selected mini-slot.

5. The VLC method of claim 1, wherein the data rate is determined based on an allocation state of wireless resources, a type of a VLC service being provided to the VLC terminal, and data being transmitted to the VLC terminal.

6. The VLC method of claim 1, wherein the frame includes a start flag period, a control information period in which the control information is included, and n time slot periods,

wherein the control information includes an AP ID, a service type indicating a type of a VLC service being provided to the VLC terminal, a duplex mode indicating a mode for configuring an uplink channel and a downlink channel of a frame, an uplink start slot, a frame length, a reference rate, and information concerning each time slot.

7. The VLC method of claim 6, wherein the information concerning each time slot includes a type corresponding to the time slot, an ID of a VLC terminal to which the time slot is allocated, and a data rate of the time slot.

8. The VLC method of claim 7, wherein the data rate is determined by a combination of the reference rate and the data rate of the time slot.

9. A Visible Light Communication (VLC) method in an Access Point (AP) in a VLC system, comprising:

receiving an initial access request on a selected mini-slot among a plurality of mini-slots constituting a control slot;

allocating an uplink time slot to correspond to the selected mini-slot, and transmitting allocation information for the uplink time slot along with control information in a frame;

upon receiving an association request on the uplink time slot, allocating an association Identifier (ID) to a VLC terminal that sent the association request, and transmitting the association ID to the VLC terminal along with a response to the association request; and

receiving data that is transmitted at a data rate appointed to the VLC terminal based on the control information in the frame using the association ID and the uplink time slot.

10. The VLC method of claim 9, wherein the data rate is determined based on an allocation state of wireless resources, a type of a VLC service being provided to the VLC terminal, and data being transmitted to the VLC terminal.

11. The VLC method of claim 9, wherein the frame includes a start flag period, a control information period in which the control information is included, and n time slot periods,

wherein the control information includes an AP ID, a service type indicating a type of a VLC service being provided to the VLC terminal, a duplex mode indicating a mode for configuring an uplink channel and a downlink channel of a frame, an uplink start slot, a frame length, a reference rate, and information concerning each time slot.

12. The VLC method of claim 11, wherein the information concerning each time slot includes a type corresponding to the time slot, an ID of a VLC terminal to which the time slot is allocated, and a data rate of the time slot.

13. The VLC method of claim 12, wherein the data rate is determined by a combination of the reference rate and the data rate of the time slot.

14. A Visible Light Communication (VLC) system, comprising:

a VLC terminal for requesting initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame, sending an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame, and transmitting data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot; and

the AP for receiving an initial access request on the selected mini-slot among the plurality of mini-slots constituting the control slot;

allocating an uplink time slot to correspond to the selected mini-slot, and transmitting allocation information for the uplink time slot along with control information in a frame, upon receiving an association request on the uplink time slot, allocating an association ID to a VLC terminal that sent the association request, and transmitting the association ID to the VLC terminal along with a response to the association request, and receiving data that is transmitted at a data rate appointed to the VLC terminal based on the control information in the frame using the association ID and the uplink time slot.

15. The VLC system of claim 14, wherein the VLC terminal re-performs the initial access request if the uplink time slot allocated to correspond to the selected mini-slot does not exist in the control information in the frame.

16. The VLC system of claim 14, wherein the VLC terminal re-performs the association request if there is no response to the association request within an association wait time after the association request.

17. The VLC system of claim 14, wherein to request the initial access, the VLC terminal determines a position of the control slot in the frame and a number of mini-slots constituting the control slot by analyzing the control information in the frame, selects a backoff timer value, selects a mini-slot in a frame having a backoff timer value of zero (0) by decreasing the backoff timer value by one on a frame basis, and requests initial access by transmitting a control symbol on the selected mini-slot.

18. The VLC system of claim 14, wherein the data rate is determined based on an allocation state of wireless resources, a type of a VLC service being provided to the VLC terminal, and data being transmitted to the VLC terminal.

19. The VLC system of claim 14, wherein the frame includes a start flag period, a control information period in which the control information is included, and n time slot periods,

wherein the control information includes an AP ID, a service type indicating a type of a VLC service being provided to the VLC terminal, a duplex mode indicating a mode for configuring an uplink channel and a downlink channel of a frame, an uplink start slot, a frame length, a reference rate, and information about each time slot.

20. The VLC system of claim 19, wherein the information about each time slot includes a type corresponding to the time slot, an ID of a VLC terminal to which the time slot is allocated, and a data rate of the time slot.

21. The VLC system of claim 20, wherein the data rate is determined by a combination of the reference rate and the data rate of the time slot.