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EP-4736558-A1 - DYNAMIC SUB-CHANNEL PRE-ALLOCATION

EP4736558A1EP 4736558 A1EP4736558 A1EP 4736558A1EP-4736558-A1

Abstract

An access point (AP) in a wireless network, the AP comprising a memory and a processor coupled to the memory, the processor is configured obtain a transmission opportunity (TXOP) or service period (SP), transmit, to a first station (STA) during the TXOP or the SP, an indication allocating a first subchannel to the first STA at a first transmission start time, wherein the first subchannel is out of an operating channel width of the first STA, transmit, to the second STA, an indication allocating a second subchannel to the second STA at a second transmission start time, transmit, to the first STA during the TXOP or the SP on the first subchannel, a first frame at the first transmission start time, and transmit, to the second STA during the TXOP or the SP on the second subchannel, a second frame at the second transmission start time.

Inventors

  • Ratnam, Vishnu Vardhan
  • NG, BOON LOONG
  • SHAFIN, Rubayet
  • NAYAK, Peshal
  • QI, YUE
  • JEN, Elliot

Assignees

  • Samsung Electronics Co., Ltd.

Dates

Publication Date
20260506
Application Date
20241011

Claims (15)

  1. An access point, AP, in a wireless network, the AP comprising: a memory; and a processor coupled to the memory, the processor configured to: obtain a transmission opportunity, TXOP, or service period, SP; transmit, to a first station, STA, during the TXOP or the SP, an indication allocating a first subchannel among one or more subchannels to the first STA at a first transmission start time, wherein the first subchannel is out of an operating channel width of the first STA; transmit, to a second STA during the TXOP or the SP, an indication allocating a second subchannel among the one or more subchannels to the second STA at a second transmission start time, wherein the second subchannel is out of an operating channel width of the second STA; transmit, to the first STA during the TXOP or the SP on the first subchannel, a first frame at the first transmission start time; and transmit, to the second STA during the TXOP or the SP on the second subchannel, a second frame at the second transmission start time.
  2. The AP of claim 1, wherein the processor is further configured to receive a third frame, from the first STA, wherein the third frame includes information associated with at least one of: a capability of supporting allocation of a subchannel outside of the operating channel width of the first STA, or a channel switch time required by the first STA to switch to an allocated channel, wherein the first transmission start time is determined based on the channel switch time.
  3. The AP of claim 1 or claim 2, wherein the indications allocating the first subchannel and the second subchannel are transmitted within a third frame, wherein the processor is further configured to, at a beginning of the TXOP or the SP, transmit the third frame indicating at least one of: one or more identifiers of associated STAs the AP intends to serve within the TXOP or the SP, a transmission start time applicable to each of the identified one or more STAs, an allocation of a sub-channel for transmission of a response to the third frame, if the response is solicited from the one or more identified STAs, allocations of one or more sub-channels allocated to each of the one or more identified STAs for transmissions within the TXOP or the SP, allocations of one or more 20 MHz channels to be used for preamble detection by each of the one or more identified STAs, or a switch back time after which the one or more identified STAs are expected to return to a primary channel.
  4. The AP of any one of the preceding claims, wherein the processor is further configured to: transmit, to a third STA during the TXOP or the SP, an indication allocating the second subchannel among the one or more subchannels to the third STA at the first transmission start time; and transmit, to the third STA during the TXOP or the SP on the second subchannel, a third frame at the first transmission start time.
  5. The AP of any one of the preceding claims, wherein the processor is further configured to, before the first transmission start time, transmit one or more of: a padding field within a third frame, wherein the third frame includes the indication allocating the first subchannel to the first STA, a fourth frame, wherein the fourth frame includes the indication allocating the second subchannel among the one or more subchannels to the second STA, or a fifth frame, wherein the fifth frame is a data frame or a null data packet with padding.
  6. The AP of any one of the preceding claims, wherein the processor is further configured to end frame transmissions to the one or more STAs before the end of the TXOP to enable the one or more STAs to switch back to the primary channel.
  7. The AP of any one of the preceding claims, wherein the processor is further configured to transmit a third frame to indicate a capability to support allocation of a subchannel outside of an operating channel width of an associated STA, wherein the associated STA can be allocated one or more subchannels of the TXOP or the SP that are outside of the associated STA's operating channel width.
  8. The AP of any one of the preceding claims, wherein a third STA is operating in enhanced multi-link single radio (EMLSR) mode or enhanced multi-link multi-radio, EMLMR, mode, wherein the processor is configured to: exclude the third STA from operation on a subchannel outside of an operating channel width of the third STA, or determine a transmission start time for the third STA based on a channel switch time required by the third STA and a padding delay required by the third STA for EMLSR or EMLMR operation, and transmit an indication of a subchannel allocation to the third STA in an EMLSR or EMLMR control frame.
  9. The AP of any one of the preceding claims, wherein the indication allocating the first subchannel among the one or more subchannels to the first STA is included in a third frame, wherein the third frame comprises at least one of: whether the first subchannel can be used by the first STA for peer-to-peer transmissions, a duration for which the first subchannel can be used for peer-to-peer transmissions, an identifier of other STA allocated to the same subchannel by the AP, or a transmit power and modulation and coding scheme restrictions applicable for the peer-to-peer transmissions.
  10. A non-access point station, non-AP STA, in a wireless network, the non-AP STA comprising: a memory; and a processor coupled to the memory, the processor configured to: transmit, to an AP, a first frame indicating a capability to operate one or more subchannels out of the primary channel; receive, during a TXOP or SP, a second frame from the AP that indicates a subchannel allocation and a transmission start time; and switch to the indicated subchannel before the transmission start time, wherein the indicated subchannel is outside of the operating channel width of the non-AP STA.
  11. The non-AP STA of claim 10, wherein the processor is further configured to receive, on the subchannel starting at the transmission start time, frames from the AP.
  12. The non-AP STA of claim 10 or claim 11, wherein the processor is further configured to transmit to the AP a third frame indicating at least one of: enablement or disablement of supporting operation on a subchannel outside of the operating channel width by the non-AP STA, one or more supported subchannels outside the operating channel width by the non-AP STA, bandwidth, spatial stream and modulation and coding scheme supported by the non-AP STA when receiving transmissions outside the operating channel width, or capability of the non-AP STA to be pre-allocated a subchannel, wherein the transmission start time to the non-AP STA may not be immediately after the indication of the allocation.
  13. The non-AP STA of any one of claims 10 to 12, wherein the processor is further configured to, upon receiving the second frame, immediately switching to the indicated subchannel or switching to the indicated subchannel at or before the transmission start time.
  14. The non-AP STA of any one of claims 10 to 13, wherein the processor is further configured to switch back to a primary channel based on at least one of: an indication of the end of the TXOP or the SP time and the channel switch time needed by the non-AP STA to switch channels; a detection of the indicated subchannel to be idle for more than a threshold time after the indicated transmission start time; a detection of a particular frame on the indicated subchannel that corresponds to another basic service set, BSS, or that the transmit address or receive address of the particular frame does not correspond to the AP; or a determination that no frames are received from the AP within a threshold time after the indicated start time.
  15. The non-AP STA of any one of claims 10 to 14, wherein the process is further configured to perform preamble detection on a 20 MHz channel that is determined based on the subchannel allocated to the non-AP STA.

Description

DYNAMIC SUB-CHANNEL PRE-ALLOCATION This disclosure relates generally to a wireless communication system, and more particularly to, for example, but not limited to, dynamic sub-channel pre-allocation. Wireless local area network (WLAN) technology has evolved toward increasing data rates and continues its growth in various markets such as home, enterprise and hotspots over the years since the late 1990s. WLAN allows devices to access the internet in the 2.4 GHz, 5GHz, 6GHz or 60 GHz frequency bands. WLANs are based on the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standards. IEEE 802.11 family of standards aims to increase speed and reliability and to extend the operating range of wireless networks. WLAN devices are increasingly required to support a variety of delay-sensitive applications or real-time applications such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and unmanned vehicles. To implement extremely low latency and extremely high throughput required by such applications, multi-link operation (MLO) has been suggested for the WLAN. The WLAN is formed within a limited area such as a home, school, apartment, or office building by WLAN devices. Each WLAN device may have one or more stations (STAs) such as the access point (AP) STA and the non-access-point (non-AP) STA. The MLO may enable a non-AP multi-link device (MLD) to set up multiple links with an AP MLD. Each of multiple links may enable channel access and frame exchanges between the non-AP MLD and the AP MLD independently, which may reduce latency and increase throughput. The description set forth in the background section should not be assumed to be prior art merely because it is set forth in the background section. The background section may describe aspects or embodiments of the present disclosure. FIG. 1 illustrates an example of a wireless network in accordance with an embodiment. FIG. 2a illustrates an example of AP in accordance with an embodiment. FIG. 2b illustrates an example of STA in accordance with an embodiment. FIG. 3 illustrates an example of multi-link communication operation in accordance with an embodiment. FIG. 4 illustrates a channel access procedure on a secondary channel via channel bonding in accordance with an embodiment. FIG. 5 illustrates an extremely high throughput (EHT) Operation element transmitted by an AP in accordance with an embodiment. FIG. 6 illustrates a high throughput (HT) Operation element transmitted by an AP in accordance with an embodiment. FIG. 7 illustrates a very high throughput (VHT) Capabilities element transmitted by an AP in accordance with an embodiment. FIG. 8 illustrates a high efficiency multi-user physical layer protocol data unit (HE MU PPDU) format in accordance with an embodiment. FIG. 9 illustrates a multi-user request to send (MU-RTS) Trigger frame format in accordance with an embodiment. FIG. 10 illustrates different elements and fields used for subchannel specific transmission (SST) negotiation in accordance with an embodiment. FIG. 11 illustrates an example of wasted basic service set (BSS) bandwidth when all associated STAs only support a narrow bandwidth in accordance with an embodiment. FIG. 12 illustrates STAs performing subchannel switch within a transmission opportunity (TXOP) based on pre-allocation from the AP in accordance with an embodiment. FIG. 13 illustrates a dynamic subchannel operation (DSO) Capability element indication by a STA/MLD in accordance with an embodiment. FIG. 14 illustrates a DSO Mode Notification frame in accordance with an embodiment. FIG. 15 illustrates two different mechanisms for sub-channel allocation for STAs that are served within the TXOP in accordance with an embodiment. FIG. 16 illustrates an example of the subchannel allocation using an Action No Ack frame in accordance with an embodiment. FIG. 17 illustrates an example of the subchannel allocation using a Delayed ACK Trigger frame in accordance with an embodiment. FIG. 18 illustrates an example of the subchannel allocation using a No ACK Trigger frame in accordance with an embodiment. FIG. 19 illustrates an example illustration a Common Info field in accordance with an embodiment. FIG. 20 illustrates using subchannel allocation frames or data frames to protect the channel switch time required by STAs in accordance with an embodiment. FIG. 21 illustrates the benefits of using separate Subchannel Allocation frames for the STAs in accordance with an embodiment. FIG. 22 illustrates a flow chart of an example processes by an AP for supporting DSO operation with pre-allocation in accordance with an embodiment. FIG. 23 illustrates a flow chart of an example process performed by a non-AP STA for operating in DSO mode with pre-allocation in accordance with an embodiment. FIG. 24 illustrates sub-channel allocation by the AP in the beginning of a TXOP to all the DSO STAs that are served within the TXOP in accordance with an embodiment. In one or