NODE DEVICE, NETWORK SYSTEM, AND METHOD FOR DISCOVERING NEIGHBOR OF NODE DEVICE IN TVWS COMMUNICATION ENVIRONMENT

• US 20160249391A1
• Filed: 02/19/2016
• Published: 08/25/2016
• Est. Priority Date: 02/25/2015
• Status: Active Grant

• Current Assignee: Ajou University Industry
• Original Assignee: Ajou University Industry
• Inventors: KIM, Jae Bum, HAN, Ji Na, KO, Young Bae
• Granted Patent: US 9,980,150 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

A node device using a TV white space (TVWS) includes a decision unit for comparing energy levels of a first sub-channel and at least one second sub-channel adjacent to the first sub-channel among a plurality of sub-channels with respect to a digital TV (DTV) channel including the plurality of sub-channels and deciding whether the DTV channel is an available channel, and a discovery unit for, if the DTV channel is decided as the available channel, discovering a beacon by scanning the first sub-channel in the DTV channel.

Claims

1. A node device using a TV white space (TVWS), comprising:

a decision unit configured to compare energy levels of a first sub-channel and at least one second sub-channel adjacent to the first sub-channel among a plurality of sub-channels with respect to a digital TV (DTV) channel including the plurality of sub-channels and decide whether the DTV channel is an available channel; and

a discovery unit configured to, if the DTV channel is decided as the available channel, discover a beacon by scanning the first sub-channel in the DTV channel.

2. The node device of claim 1, wherein the first sub-channel is a sub-channel corresponding to the center frequency band of the DTV channel, and the second sub-channel is a sub-channel corresponding to a frequency band adjacent to the center frequency band of the DTV channel.

3. The node device of claim 2, wherein the frequency band of the second sub-channel is continued to that of the first sub-channel.

4. The node device of claim 2, wherein the frequency band of the second sub-channel is not continued to that of the first sub-channel.

5. The node device of claim 1, wherein the decision unit calculates a correlation value between the energy level of the first sub-channel and the energy level of the second sub-channel, and decides whether the DTV channel is the available channel by comparing the calculated correlation value with a predetermined critical value.

6. The node device of claim 5, wherein the correlation value is calculated according to the following equation;

7. The node device of claim 1, wherein the decision unit measures the energy level of the first sub-channel and the energy level of the second sub-channel by using clear channel assessment (CCA).

8. The node device of claim 1, further comprising a network connection unit configured to perform a connection procedure on a TVWS network by using the discovered beacon.

9. A TVWS network system, comprising:

a first node device configured to select, as an available channel, at least one DTV channel among a plurality of DTV channels, based on acquired available channel information, and transmit a beacon by using a pilot channel in the DTV channel selected as the available channel; and

a second node device configured to compare energy levels of a pilot channel in a DTV channel corresponding to each of the plurality of DTV channel and at least one adjacent channel, decide whether the corresponding DTV channel is the DTV channel selected as the available channel, and discover a beacon by scanning the pilot channel in the DTV channel selected as the available channel.

10. The network system of claim 9, wherein each of the plurality of DTV channels includes a plurality of sub-channels, and

wherein the first node device and the second node device select any one of the plurality of sub-channels as the pilot channel according to the following equation;

11. The network system of claim 10, wherein the second node device selects, as the adjacent channel, a sub-channel adjacent to the sub-channel selected as the pilot channel among the plurality of sub-channels.

12. The network system of claim 9, wherein the second node device calculates a correlation value between the energy level of the pilot channel and the energy level of the adjacent channel, and decides whether the corresponding DTV channel is the DTV channel selected as the available channel by comparing the calculated correlation value with a predetermined critical value.

13. A method for discovering a neighbor of a node device in a TVWS communication environment, the method comprising:

comparing energy levels of a first sub-channel and at least one second sub-channel adjacent to the first sub-channel among a plurality of sub-channels with respect to a DTV channel including the plurality of sub-channels and deciding whether the DTV channel is an available channel; and

if the DTV channel is decided as the available channel, discover a beacon by scanning the first sub-channel in the DTV channel.

14. The method of claim 13, wherein the first sub-channel is a sub-channel corresponding to the center frequency band of the DTV channel, and the second sub-channel is a sub-channel corresponding to a frequency band adjacent to the center frequency band of the DTV channel.

15. The method of claim 14, wherein the frequency band of the second sub-channel is continued to that of the first sub-channel.

16. The method of claim 14, wherein the frequency band of the second sub-channel is not continued to that of the first sub-channel.

17. The method of claim 13, wherein the deciding of whether the DTV channel is the available channel includes:

calculating a correlation value between the energy level of the first sub-channel and the energy level of the second sub-channel; and

deciding whether the DTV channel is the available channel by comparing the calculated correlation value with a predetermined critical value.

18. The method of claim 17, wherein the correlation value is calculated according to the following equation;

19. The method of claim 13, wherein in the deciding of whether the DTV channel is the available channel, the energy level of the first sub-channel and the energy level of the second sub-channel are measured by using CCA.

20. The method of claim 13, further comprising, after the discovering of the beacon, performing a connection procedure on a TVWS network by using the discovered beacon.