METHOD FOR ADJUSTING CONTENTION WINDOW SIZE CONSIDERING PRIORITY CLASS IN WIRELESS ACCESS SYSTEM SUPPORTING UNLICENSED BAND, AND APPARATUS FOR SUPPORTING SAME

• US 20180249484A1
• Filed: 07/12/2016
• Published: 08/30/2018
• Est. Priority Date: 09/02/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: KIM, Seonwook, AHN, Joonkui, YANG, Suckchel, KIM, Kijun, KIM, Byounghoon, SEO, Hanbyul, PARK, Hanjun, HWANG, Daesung
• Granted Patent: US 10,455,605 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/569 of the traffic information
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

The present invention relates to a wireless access system supporting an unlicensed band, various methods for adjusting a contention window size, methods for performing a carrier sensing process in a single engine and a multi-engine, and an apparatus supporting the same. As one embodiment of the invention, a method for adjusting a contention window size (CWS) in a wireless access system supporting an unlicensed band may comprise: a step of setting a contention window size (CWS) necessary for performing a channel access process for each of priority classes; a step of performing a channel access process for a particular priority class in a channel in an unlicensed band on the basis of the set CWS; a step of performing a downlink transmission related to the particular priority class if it is determined that the channel in the unlicensed band is in an idle state as a result of the channel access process; and a step of making adjustments for all CWS'"'"' of priority classes if a triggering event, which relates to a downlink transmission and increases or reduces the CWS for the particular priority class, occurs.

Claims

1. A method for adjusting a contention window size (CWS) in a wireless access system supporting an unlicensed band, the method comprising:

configuring a CWS required to perform a channel access procedure for each of priority classes;

performing the channel access procedure for a specific priority class based on the configured CWS in a channel of the unlicensed band;

performing a downlink transmission related to the specific priority class, when the channel of the unlicensed band is determined as an idle state as a result of the channel access procedure; and

adjusting CWSs for all of the priority classes, when a triggering event for increasing or decreasing a CWS for the specific priority class is occurred, wherein the triggering event is related to the DL transmission.

2. The method according to claim 1, wherein the configuring of a CWS comprises configuring minimum and maximum values of the CWS for each of the priority classes.

3. The method according to claim 2, wherein upon occurrence of a triggering event for increasing the CWS, each of CWSs configured for all of the priority classes is increased to an allowed next higher value.

4. The method according to claim 2, wherein the CWS is increased to the maximum value according to the number of occurrences of the triggering event.

5. The method according to claim 1, wherein a predetermined random backoff count is configured, and if the random backoff count expires and the channel of the unlicensed band is determined to be an idle state, the downlink transmission is performed in the channel access procedure.

6. The method according to claim 1, wherein if two or more serving cells are configured in the unlicensed band, the channel access procedure is performed for each of the two or more serving cells.

7. A base station for adjusting a contention window size (CWS) in a wireless access system supporting an unlicensed band, the base station comprising:

a transmitter; and

a processor configured to support CWS adjustment,

wherein the processor is configured to configure a CWS required to perform a channel access procedure for each of priority classes, to perform the channel access procedure for a specific priority class based on the configured CWS in a channel of the unlicensed band, to perform a downlink transmission related to the specific priority class by controlling the transmitter, when the channel of the unlicensed band is determined as an idle state as a result of the channel access procedure, and to adjust CWSs for all of the priority classes when a triggering event for increasing or decreasing a CWS for the specific priority class is occurred, wherein the triggering event is related to the DL transmission.

8. The base station according to claim 7, wherein when the CWS is configured, minimum and maximum values of the CWS are configured for each of the priority classes.

9. The base station according to claim 8, wherein upon occurrence of a triggering event for increasing the CWS, each of CWSs configured for all of the priority classes is increased to an allowed next higher value.

10. The base station according to claim 8, wherein the CWS is increased to the maximum value according to the number of occurrences of the triggering event.

11. The base station according to claim 7, wherein a predetermined random backoff count is configured, and if the random backoff count expires and the channel of the unlicensed band is determined to be an idle state, the downlink transmission is performed, in the channel access procedure.

12. The base station according to claim 7, wherein if two or more serving cells are configured in the unlicensed band, the channel access procedure is performed for each of the two or more serving cells.