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EP-4742811-A1 - METHOD AND DEVICE FOR CHANNEL ACCESS FOR PREEMPTION TRANSMISSION IN WIRELESS LAN

EP4742811A1EP 4742811 A1EP4742811 A1EP 4742811A1EP-4742811-A1

Abstract

Disclosed are a method and a device for channel access for preemption transmission in a wireless LAN. The method of a first communication node comprises the steps of: receiving a first frame including preemption information from an AP; selecting a counter value on the basis of CW information included in the preemption information; reducing the counter value for each preconfigured unit; and transmitting a first LL frame when the counter value reaches 0.

Inventors

  • HWANG, SUNG HYUN
  • KANG, KYU MIN
  • KIM, YONG HO
  • MOON, Ju Seong

Assignees

  • Electronics and Telecommunications Research Institute

Dates

Publication Date
20260513
Application Date
20240617

Claims (20)

  1. A method of a first communication node, comprising: receiving a first frame including preemption information from an access point (AP); selecting a counter value based on contention window (CW) information included in the preemption information; decrementing the counter value at a preconfigured unit; and transmitting a first low latency (LL) frame when the counter value reaches 0.
  2. The method according to claim 1, wherein the selecting of the counter value comprises: identifying a window [0, preemption contention window (pCW)] based on the CW information; and selecting the counter value within the window [0, pCW], wherein pCW is a CW configured for preemption operations.
  3. The method according to claim 1, wherein the transmitting of the first LL frame comprises: transmitting the first LL frame after a preset time from an end time of a frame received from the AP, wherein the preset time is a time required to switch an operation mode of the first communication node from a transmission mode to a reception mode or a time required to switch the operation mode of the first communication node from the reception mode to the transmission mode.
  4. The method according to claim 1, further comprising: in response to LL traffic existing in the first communication node after transmission of the first LL frame, selecting a new counter value based on the CW information; and decrementing the new counter value at the preconfigured unit in order to transmit the LL traffic.
  5. The method according to claim 1, wherein the preconfigured unit is a frame transmission of the AP or aSlotTime.
  6. The method according to claim 1, wherein the first LL frame is transmitted in an interval between frame transmissions of the AP.
  7. The method according to claim 1, wherein the first LL frame is transmitted within an X interframe space (XIFS) from an end time of a frame received from the AP.
  8. The method according to claim 7, wherein a length of the XIFS is indicated by length information included in the preemption information.
  9. The method according to claim 1, wherein the counter value is maintained when a second LL frame of a second communication node is transmitted before transmission of the first LL frame, and the counter value is decremented again at the preconfigured unit after termination of transmission of the second LL frame.
  10. The method according to claim 1, wherein a length of the first LL frame is less than or equal to a maximum length indicated by maximum length information included in the preemption information.
  11. A method of a first communication node, comprising: receiving a first frame including preemption information from an access point (AP); identifying probability information included in the preemption information; determining whether to transmit a first low latency (LL) frame based on the probability information; and in response to determining to transmit the first LL frame, transmitting the first LL frame.
  12. The method according to claim 11, wherein the determining of whether to transmit the first LL frame comprises: determining a unique probability based on the probability information and unique information of the first communication node; and comparing the unique probability with a threshold indicated by threshold information included in the preemption information, wherein the first LL frame is determined to be transmitted when the unique probability is greater than or equal to the threshold, and the first LL frame is determined not to be transmitted when the unique probability is less than the threshold.
  13. The method according to claim 11, wherein the transmitting of the first LL frame comprises: transmitting the first LL frame after a preset time from an end time of the first frame received from the AP, wherein the preset time is a time required to switch an operation mode of the first communication node from a transmission mode to a reception mode or a time required to switch the operation mode of the first communication node from the reception mode to the transmission mode.
  14. The method according to claim 11, wherein the first LL frame is transmitted within an X interframe space (XIFS) from an end time of the first frame received from the AP.
  15. The method according to claim 14, wherein a length of the XIFS is indicated by length information included in the preemption information.
  16. The method according to claim 11, wherein a length of the first LL frame is less than or equal to a maximum length indicated by maximum length information included in the preemption information.
  17. A first communication node comprising a processor, wherein the processor causes the first communication node to perform: receiving a first frame including preemption information from an access point (AP); selecting a counter value based on contention window (CW) information included in the preemption information; decrementing the counter value at a preconfigured unit; and transmitting a first low latency (LL) frame when the counter value reaches 0.
  18. The first communication node according to claim 17, wherein in the selecting of the counter value, the processor causes the first communication node to perform: identifying a window [0, preemption contention window (pCW)] based on the CW information; and selecting the counter value within the window [0, pCW], wherein pCW is a CW configured for preemption operations.
  19. The first communication node according to claim 17, wherein in the transmitting of the first LL frame, the processor causes the first communication node to perform: transmitting the first LL frame after a preset time from an end time of a frame received from the AP, wherein the preset time is a time required to switch an operation mode of the first communication node from a transmission mode to a reception mode or a time required to switch the operation mode of the first communication node from the reception mode to the transmission mode.
  20. The first communication node according to claim 17, wherein the first LL frame is transmitted within an X interframe space (XIFS) from an end time of a frame received from the AP.

Description

[Technical Field] The present disclosure relates to a wireless local area network (LAN) communication technique, and more particularly, to a channel access technique for preemption operations for low latency (LL) traffic transmission. [Background Art] Recently, as the spread of mobile devices expands, a wireless local area network technology capable of providing fast wireless communication services to mobile devices is in the spotlight. The wireless LAN technology may be a technology that supports mobile devices such as smart phones, smart pads, laptop computers, portable multimedia players, embedded devices, and the like to wirelessly access the Internet based on wireless communication technology. As applications requiring higher throughput and applications requiring real-time transmission occur, the IEEE 802.11be standard, which is an extreme high throughput (EHT) wireless LAN technology, is being developed. The goal of the IEEE 802.11be standard may be to support a high throughput of 30 Gbps. The IEEE 802.11be standard may support techniques for reducing a transmission latency. In addition, the IEEE 802.11be standard can support a more expanded frequency bandwidth (e.g., 320 MHz bandwidth), multi-link transmission and aggregation operations including multi-band operations, multi-access point (AP) transmission operations, and/or efficient retransmission operations (e.g., hybrid automatic repeat request (HARQ) operations). The Ultra High Reliability (UHR) wireless LAN technology, IEEE 802.11bn standard, is currently under development. The IEEE 802.11bn standard can support technologies for enhancing reliability and/or low-latency technologies. In a wireless LAN supporting the IEEE 802.11bn standard, technologies for enhancing reliability and/or enabling low-latency communication may be necessary. Meanwhile, the technologies that are the background of the present disclosure are written to improve the understanding of the background of the present disclosure and may include content that is not already known to those of ordinary skill in the art to which the present disclosure belongs. [Disclosure] [Technical Problem] The present disclosure is directed to providing a channel access method and apparatus for preemption operations for low latency (LL) traffic transmission. [Technical Solution] A method of a first communication node, according to exemplary embodiments of the present disclosure for achieving the above-described objective, may comprise: receiving a first frame including preemption information from an access point (AP); selecting a counter value based on contention window (CW) information included in the preemption information; decrementing the counter value at a preconfigured unit; and transmitting a first low latency (LL) frame when the counter value reaches 0. The selecting of the counter value may comprise: identifying a window [0, preemption contention window (pCW)] based on the CW information; and selecting the counter value within the window [0, pCW], wherein pCW is a CW configured for preemption operations. The transmitting of the first LL frame may comprise: transmitting the first LL frame after a preset time from an end time of a frame received from the AP, wherein the preset time may be a time required to switch an operation mode of the first communication node from a transmission mode to a reception mode or a time required to switch the operation mode of the first communication node from the reception mode to the transmission mode. The method may further comprise: in response to LL traffic existing in the first communication node after transmission of the first LL frame, selecting a new counter value based on the CW information; and decrementing the new counter value at the preconfigured unit in order to transmit the LL traffic. The preconfigured unit may be a frame transmission of the AP or aSlotTime. The first LL frame may be transmitted in an interval between frame transmissions of the AP. The first LL frame may be transmitted within an X interframe space (XIFS) from an end time of a frame received from the AP. A length of the XIFS may be indicated by length information included in the preemption information. The counter value may be maintained when a second LL frame of a second communication node is transmitted before transmission of the first LL frame, and the counter value may be decremented again at the preconfigured unit after termination of transmission of the second LL frame. A length of the first LL frame may be less than or equal to a maximum length indicated by maximum length information included in the preemption information. A method of a first communication node, according to exemplary embodiments of the present disclosure for achieving the above-described objective, may comprise: receiving a first frame including preemption information from an access point (AP); identifying probability information included in the preemption information; determining whether to transmit a