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US-12627406-B2 - Quick recovery indication and retransmission request

US12627406B2US 12627406 B2US12627406 B2US 12627406B2US-12627406-B2

Abstract

Methods and apparatuses for facilitating, in multi-link devices (MLDs) that are capable of exchanging an Aggregated MAC Protocol Data Unit (A-MPDU), simultaneous transmission of the A-MPDU and retransmission of failed MPDUs of the A-MPDU. A non-access point (AP) MLD comprises STAs, each comprising a transceiver configured to form a link with a corresponding AP of an AP MLD, and a processor. A first transceiver is configured to receive, from the AP MLD on a first of the links, an A-MPDU comprised of multiple MPDUs. the processor is configured to detect, during reception of the A-MPDU, that at least one of the MPDUs has not been received. A second transceiver is configured to transmit, to the AP MLD on a second of the links, a request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete.

Inventors

  • Ahmed Atef Ibrahim Ibrahim
  • Boon Loong Ng
  • Vishnu Vardhan Ratnam
  • Rubayet Shafin
  • Junsu CHOI

Assignees

  • SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date
20260512
Application Date
20221230

Claims (20)

  1. 1 . A non-access point (AP) multi-link device (MLD), comprising: stations (STAs), each comprising a transceiver configured to form a link with a corresponding AP of an AP MLD; and a processor operably coupled to the STAs, wherein a first of the transceivers is further configured to receive, from the AP MLD on a first of the links, an aggregated MAC protocol data unit (A-MPDU) comprised of multiple MPDUs, wherein the processor is configured to detect, during reception of the A-MPDU, that at least one of the MPDUs has not been received, and wherein a second of the transceivers is further configured to transmit, to the AP MLD on a second of the links, a request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete.
  2. 2 . The non-AP MLD of claim 1 , wherein at least one of the transceivers is further configured to: receive, from the AP MLD, a retransmission of the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete, and transmit, to the AP MLD, a multi-link block-acknowledgement (ML-BA) for the A-MPDU after reception of all of the multiple MPDUs is complete.
  3. 3 . The non-AP MLD of claim 1 , wherein: the processor is further configured to generate an extremely high throughput (EHT) capabilities element including an indication that the non-AP MLD is capable of transmitting the request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete, and at least one of the transceivers is further configured to transmit the EHT capabilities element to the AP MLD before reception of the A-MPDU begins.
  4. 4 . The non-AP MLD of claim 1 , wherein: the processor is further configured to set up block acknowledgement (BA) with the AP MLD such that a BA request (BAR) frame or a BA frame can include an indication to activate or terminate a quick recovery mode, and while the quick recovery mode is activated, the second link is reserved for the transmission of the request to retransmit the at least one MPDU and for a retransmission of the at least one MPDU.
  5. 5 . The non-AP MLD of claim 4 , wherein: the processor is further configured to generate the BAR frame or the BA frame to include: a quick recovery activation request frame that indicates a request for activation or termination of the quick recovery mode using the second link; or a quick recovery response element that indicates acceptance or denial of a received request for activation or termination of the quick recovery mode using the second link, and at least one of the transceivers is further configured to transmit the BAR frame or the BA frame to the AP MLD.
  6. 6 . The non-AP MLD of claim 1 , wherein: the processor is further configured to generate a BA frame as the request to retransmit the at least one MPDU, and the BA frame includes a bitmap that identifies each of the at least one MPDUs to be retransmitted.
  7. 7 . The non-AP MLD of claim 1 , wherein the processor is further configured to: after detecting that the at least one MPDU has not been received, determine whether a transmission opportunity (TXOP) can be obtained on any of the links, and based on a determination that the TXOP can be obtained on the second link, select the second link for the transmission of the request to retransmit the at least one MPDU on the second link.
  8. 8 . An access point (AP) multi-link device (MLD), comprising: APs, each comprising a transceiver configured to form a link with a corresponding station (STA) of a non-AP MLD; and a processor operably coupled to the APs, wherein a first of the transceivers is further configured to transmit, to the non-AP MLD on a first of the links, an aggregated MAC protocol data unit (A-MPDU) comprised of multiple MPDUs, wherein a second of the transceivers is further configured to receive, from the non-AP MLD on a second of the links, a request to retransmit at least one of the MPDUs on the second link before reception of the A-MPDU by the non-AP MLD on the first link is complete, and wherein the processor is configured to determine, based on the received request to retransmit the at least one MPDU, that the at least one MPDU was not received by the non-AP MLD.
  9. 9 . The AP MLD of claim 8 , wherein at least one of the transceivers is further configured to: transmit, to the non-AP MLD, a retransmission of the at least one MPDU on the second link before reception of the A-MPDU by the non-AP MLD on the first link is complete, and receive, from the non-AP MLD, a multi-link block-acknowledgement (ML-BA) for the A-MPDU after reception of all of the multiple MPDUs by the non-AP MLD is complete.
  10. 10 . The AP MLD of claim 8 , wherein: at least one of the transceivers is further configured to receive, from the non-AP MLD, an extremely high throughput (EHT) capabilities element before transmission of the A-MPDU begins, and the EHT capabilities element includes an indication that the non-AP MLD is capable of transmitting the request to retransmit the at least one MPDU on the second link before reception of the A-MPDU by the non-AP MLD on the first link is complete.
  11. 11 . The AP MLD of claim 8 , wherein: the processor is further configured to set up block acknowledgement (BA) with the non-AP MLD such that a BA request (BAR) frame or a BA frame can include an indication to activate or terminate a quick recovery mode, and while the quick recovery mode is activated, the second link is reserved for transmission of the request to retransmit the at least one MPDU and for a retransmission of the at least one MPDU.
  12. 12 . The AP MLD of claim 11 , wherein: at least one of the transceivers is further configured to receive the BAR frame or the BA frame from the non-AP MLD, and the BAR frame or the BA frame includes: a quick recovery activation request frame that indicates a request for activation or termination of the quick recovery mode using the second link, or a quick recovery response element that indicates acceptance or denial of a received request for activation or termination of the quick recovery mode using the second link.
  13. 13 . The AP MLD of claim 11 , wherein: the request to retransmit the at least one MPDU is a BA frame that includes a bitmap that identifies each of the at least one MPDUs to be retransmitted, and the processor is further configured to determine each of the at least one MPDUs to be retransmitted based on the bitmap included in the BA frame.
  14. 14 . The AP MLD of claim 8 , wherein: the second link is selected based on a determination, after detection that the at least one MPDU has not been received by the non-AP MLD, that a transmission opportunity (TXOP) can be obtained on the second link.
  15. 15 . A method of wireless communication performed by a non-access point (AP) multi-link device (MLD) that comprises stations (STAs) that each comprise a transceiver configured to form a link with a corresponding AP of an AP MLD, the method comprising: receiving, from the AP MLD on a first of the links, an aggregated MAC protocol data unit (A-MPDU) comprised of multiple MPDUs; detecting, during reception of the A-MPDU, that at least one of the MPDUs has not been received; and transmitting, to the AP MLD on a second of the links, a request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete.
  16. 16 . The method of claim 15 , further comprising: receiving, from the AP MLD, a retransmission of the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete; and transmitting, to the AP MLD, a multi-link block-acknowledgement (ML-BA) for the A-MPDU after reception of all of the multiple MPDUs is complete.
  17. 17 . The method of claim 15 , further comprising: generating an extremely high throughput (EHT) capabilities element including an indication that the non-AP MLD is capable of transmitting the request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete; and transmitting the EHT capabilities element to the AP MLD before reception of the A-MPDU begins.
  18. 18 . The method of claim 15 , further comprising: setting up block acknowledgement (BA) with the AP MLD such that a BA request (BAR) frame or a BA frame can include an indication to activate or terminate a quick recovery mode, wherein, while the quick recovery mode is activated, the second link is reserved for the transmission of the request to retransmit the at least one MPDU and for a retransmission of the at least one MPDU.
  19. 19 . The method of claim 15 , further comprising: generating a BA frame as the request to retransmit the at least one MPDU, such that the BA frame includes a bitmap that identifies each of the at least one MPDUs to be retransmitted.
  20. 20 . The method of claim 15 , further comprising: after detecting that the at least one MPDU has not been received, determining whether a transmission opportunity (TXOP) can be obtained on any of the links, and based on a determination that the TXOP can be obtained on the second link, selecting the second link for the transmission of the request to retransmit the at least one MPDU on the second link.

Description

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY This application claims priority under 35 U.S.C. § 119 (e) to U.S. Provisional Patent Application No. 63/300,942 filed on Jan. 19, 2022, and U.S. Provisional Patent Application No. 63/304,376 filed on Jan. 28, 2022, which are hereby incorporated by reference in their entirety. TECHNICAL FIELD This disclosure relates generally to transmission efficiency in wireless communications systems that include multi-link devices. Embodiments of this disclosure relate to methods and apparatuses that enable, in multi-link devices that are capable of exchanging an Aggregated MAC Protocol Data Unit (A-MPDU) in a wireless local area network communications system, simultaneous transmission of the A-MPDU and retransmission of failed MPDUs of the A-MPDU. BACKGROUND Wireless local area network (WLAN) technology allows devices to access the internet in the 2.4 GHz, 5 GHZ, 6 GHZ, or 60 GHz frequency bands. WLANs are based on the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standards. The IEEE 802.11 family of standards aim to increase speed and reliability and to extend the operating range of wireless networks. Block Acknowledgment (BA) is one of the major features that enable aggregation of multiple MAC Protocol Data Units (MPDUs) using one Aggregated MAC Protocol Data Unit (A-MPDU). With BA capability, multiple MPDUs in one A-MPDU can be acknowledged together in a single BA. The IEEE 802.11 baseline standard defines a protected BA mechanism whereby scoreboard context can only be updated using a robust Add Block ACK (ADDBA) Request frame that updates WinStartB and WinSizeB, where a Block ACK Request (BAR) frame is only used to indicate reception status. The recipient advances the windows after validation and responds with a robust ADDBA Response frame. After the handshake is complete, the originator updates its windows (WinStartO and WinSizeO) accordingly. The reason is that ADDBA Request and ADDBA Response frames are management frames that can be protected, while control frames such as the BAR frame cannot be protected. Hence, BAR is not robust against attacks that may interfere with the reorder buffer by changing buffer windows. Next generation extremely high throughput (EHT) WI-FI systems, e.g., IEEE 802.11be, support multiple bands of operation, called links, over which an access point (AP) and a non-AP device can communicate with each other. Thus, both the AP and non-AP device may be capable of communicating on different bands/links, which is referred to as multi-link operation (MLO). The WI-FI devices that support MLO are referred to as multi-link devices (MLDs). With MLO, it is possible for a non-access point (non-AP) MLD to discover, authenticate, associate, and set up multiple links with an AP MLD. Channel access and frame exchange is possible on each link that is set up between the AP MLD and non-AP MLD. Multi-link Block Acknowledgement (ML-BA) is another key feature that is introduced for EHT WI-FI systems, whereby a BA can be sent on any enabled link between MLDs as long as the same traffic identifier (TID) is mapped to the link that carries the BA and the link that carries the related data, e.g., Quality of Service (QoS) data. SUMMARY Embodiments of the present disclosure provide methods and apparatuses that facilitate, in MLDs that are capable of exchanging an A-MPDU in a WLAN, simultaneous transmission of the A-MPDU and retransmission of failed MPDUs of the A-MPDU. In one embodiment, a non-AP MLD is provided, comprising STAs and a processor operably coupled to the STAs. The STAs each comprise a transceiver configured to form a link with a corresponding AP of an AP MLD. A first of the transceivers is further configured to receive, from the AP MLD on a first of the links, an A-MPDU comprised of multiple MPDUs. the processor is configured to detect, during reception of the A-MPDU, that at least one of the MPDUs has not been received. A second of the transceivers is further configured to transmit, to the AP MLD on a second of the links, a request to retransmit the at least one MPDU on the second link before reception of the A-MPDU on the first link is complete. In another embodiment, an AP MLD is provided, comprising APs and a processor operably coupled to the APs. The APs each comprise a transceiver configured to form a link with a corresponding STA of a non-AP MLD. A first of the transceivers is further configured to transmit, to the non-AP MLD on a first of the links, an A-MPDU comprised of multiple MPDUs. A second of the transceivers is further configured to receive, from the non-AP MLD on a second of the links, a request to retransmit at least one of the MPDUs on the second link before reception of the A-MPDU by the non-AP MLD on the first link is complete. The processor is configured to determine, based on the received request to retransmit the at least one MPDU, that the at least one MPDU was not received by the non-AP MLD. In anoth