OPERATING METHOD OF COMMUNICATION NODE IN NETWORK SUPPORTING LICENSED AND UNLICENSED BANDS

• US 20180175975A1
• Filed: 08/05/2013
• Published: 06/21/2018
• Est. Priority Date: 08/14/2015
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: UM, Jung Sun, YOO, Sung Jin, JUNG, Hoi Yoon, PARK, Seung Keun
• Granted Patent: US 10,673,576 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1816 with retransmission of the same, encoded, message
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

An operating method of a communication node in a network supporting licensed and unlicensed bands is disclosed. An operation method of a base station comprises the steps of: transmitting a PDSCH to a UE in an unlicensed band; receiving an HARQ response to the PDSCH from the UE; and determining a size of a CW on the basis of a proportion of NACKs in HARQ responses. Therefore, a performance of a communication network can be improved.

Claims

1. An operation method of a base station in a communication network, comprising:

transmitting a physical downlink shared channel (PDSCH) to a user equipment (UE) through an unlicensed band;

receiving a hybrid automatic repeat request (HARQ) response to the PDSCH from the UE; and

determining a size of a contention window (CW) based on a negative acknowledgement (NACK) ratio of HARQ responses.

2. The operation method according to claim 1, wherein the base station transmits the PDSCHs in consecutive subframes, and the size of the CW is determined based on the HARQ response to the PDSCH transmitted through a first subframe among the consecutive subframes when a size of the first subframe is 1 millisecond.

3. The operation method according to claim 1, wherein the base station transmits the PDSCHs in consecutive subframes, the size of the CW is determined based on the HARQ responses to the PDSCHs transmitted through a first subframe (subframe #n) and a second subframe (subframe #(n+1)) among the consecutive subframes when a size of the first subframe (subframe #n) is less than 1 millisecond, and n is an integer equal to or greater than 0.

4. The operation method according to claim 1, wherein, when the PDSCH includes two codewords, the HARQ response includes HARQ responses for the two respective codewords.

5. The operation method according to claim 1, wherein the HARQ response is a bundled HARQ response for a plurality subframes among the consecutive subframes.

6. The operation method according to claim 1, wherein the size of the CW is increased when the NACK ratio is equal to or greater than a predetermined threshold.

7. The operation method according to claim 1, wherein the size of the CW is decreased when the NACK ratio is less than a predetermined threshold.

8. The operation method according to claim 1, wherein the size of the CW is determined based on the NACK ratio which is a ratio of a sum of NACKs, discontinuous transmissions (DTXs), and ANYs.

9. The operation method according to claim 1, further comprising transmitting a PDSCH to the UE based on the changed size of the CW through the unlicensed band.

10. A base station supporting an unlicensed band, comprising a processor and a memory storing at least one instruction executed by the processor, wherein the at least one instruction is configured to:

transmit a physical downlink shared channels (PDSCH) to a user equipment (UE) through an unlicensed band;

receive a hybrid automatic repeat request (HARQ) response to the PDSCH from the UE; and

determine a size of a contention window (CW) based on a negative acknowledgement (NACK) ratio of HARQ responses.

11. The base station according to claim 10, wherein the PDSCHs are transmitted through consecutive subframes, and the size of the CW is determined based on the HARQ response to the PDSCH transmitted through a first subframe among the consecutive subframes when a size of the first subframe is 1 millisecond.

12. The base station according to claim 10, wherein the PDSCHs are transmitted through consecutive subframes, the size of the CW is determined based on the HARQ responses to the PDSCHs transmitted through a first subframe (subframe #n) and a second subframe (subframe #(n+1)) among the consecutive subframes when a size of the first subframe (subframe #n) is less than 1 millisecond, and n is an integer equal to or greater than 0.

13. The base station according to claim 10, wherein, when the PDSCH includes two codewords, the HARQ response includes HARQ responses for the two respective codewords.

14. The base station according to claim 10, wherein the HARQ response is a bundled HARQ response for a plurality subframes among the consecutive subframes.

15. The base station according to claim 10, wherein the size of the CW is increased when the NACK ratio is equal to or greater than a predetermined threshold.

16. The base station according to claim 10, wherein the size of the CW is decreased when the NACK ratio is less than a predetermined threshold.

17. The base station according to claim 10, wherein the size of the CW is determined based on the NACK ratio which is a ratio of a sum of NACKs, discontinuous transmissions (DTXs), and ANYs.

18. The base station according to claim 10, wherein the at least one instruction is further configured to transmit a PDSCH to the UE based on the changed size of the CW through the unlicensed band.