Dynamic aggregated mac protocol data unit for multi-link operation

Abstract

This disclosure provides methods, components, devices and systems for multi- link wireless communications. According to certain aspects, when a wireless node is operating on multiple links, the wireless node may allocate, based on at least one parameter that is asymmetric on a first wireless link and on a second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link.

Description

DYNAMIC AGGREGATED MAC PROTOCOL DATA UNIT FOR MULTI-LINK OPERATIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Indian Patent Application No. 202341047621, filed July 14, 2023, which is assigned to the assignee hereof and hereby expressly incorporated by reference in its entirety as if fully set forth below and for all applicable purposes.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless communication, and more specifically, to techniques for managing multi-link communications in wireless networks.DESCRIPTION OF THE RELATED TECHNOLOGY

[0003] A wireless local area network (WLAN) may be formed by one or more wireless access points (APs) that provide a shared wireless communication medium for use by multiple client devices also referred to as wireless stations (STAs). The basic building block of a WLAN conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards is a Basic Service Set (BSS), which is managed by an AP. Each BSS is identified by a Basic Service Set Identifier (BSSID) that is advertised by the AP. An AP periodically broadcasts beacon frames to enable any STAs within wireless range of the AP to establish or maintain a communication link with the WLAN.SUMMARY

[0004] The systems, methods and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0005] One innovative aspect of the subject matter described in this disclosure may be implemented as a method for wireless communication at a first wireless node, comprising establishing at least a first wireless link and a second wireless link with a second wireless node; allocating, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a secondAMPDU size to the second wireless link; and communicating with the second wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

[0006] Another innovative aspect of the subject matter described in this disclosure may be implemented at an apparatus for wireless communications at a first wireless node. The apparatus includes at least one processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: establish at least a first wireless link and a second wireless link with a second wireless node; allocate, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link; and communicate with the second wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

[0007] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 shows a pictorial diagram of an example wireless communication network.

[0009] Figure 2 shows an example protocol data unit (PDU) usable for communications between a wireless access point (AP) and one or more wireless stations (STAs).

[0010] Figure 3 shows a hierarchical format of an example physical layer PDU (PPDU) usable for communications between a wireless AP and one or more wireless STAs.

[0011] Figure 4 shows a pictorial diagram of another example wireless communication network.

[0012] Figure 5 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized.

[0013] Figure 6 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized.

[0014] Figure 7 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized.

[0015] Figure 8 shows a flowchart illustrating an example process performable by a wireless node.

[0016] Figure 9 shows a block diagram of an example wireless communication device.

[0017] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTION

[0018] The following description is directed to some particular examples for the purposes of describing innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some or all of the described examples may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency (RF) signals according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, the IEEE 802.15 standards, the Bluetooth® standards as defined by the Bluetooth Special Interest Group (SIG), or the Long Term Evolution (LTE), 3G, 4G or 5G (New Radio (NR)) standards promulgated by the 3rdGeneration Partnership Project (3GPP), among others. The described examples can be implemented in any device, system or network that is capable of transmitting and receiving RF signals according to one or more of the following technologies or techniques: code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), spatial division multiple access (SDMA), ratesplitting multiple access (RSMA), multi-user shared access (MUSA), single-user (SU) multiple-input multiple-output (MIMO) and multi-user (MU)-MIMO. The described examples also can be implemented using other wireless communication protocols or RF signals suitable for use in one or more of a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless wide area network (WWAN), a wireless metropolitan area network (WMAN), or an internet of things (IOT) network.

[0019] As used herein, “wireless node” generally refers to any type of device capable of communicating wirelessly, such as an access point (AP), a wireless station (STA) serving as an AP (an AP-STA), a STA that is not serving as an AP (a non-AP STA), or a user equipment (UE).

[0020] Various aspects relate generally to wireless communication. Some aspects more specifically relate to wireless communication in systems that utilize multiple links that can have asymmetric characteristics.

[0021] The asymmetric link characteristics may pose certain practical challenges that could significantly impact performance. For example, if the system utilizes a multi-link transmission protocol that uses a shared packet numbering space, asymmetric link characteristics may result in traffic on two different paths with unequal transfer functions. As a result, packets may be processed at different rates, which may impact performance due to ordering rules with number allocation, particularly when each link is assigned a same AMDPU limit (e.g., that dictates a limit on AMPDU size / quantity of MPDUs in an AMPDU).

[0022] Such rules may dictate that packets with sequence numbers within a window or range of sequence numbers (e.g., a block acknowledgement or BA window) with a configured size must be processed before advancing window to process additional packets. Thus, if two links share a common sequence number space and one link is faster than the other (e.g., due to greater bandwidth), in cases where the faster link successfully completes transmission of multiple packets while the slower link is still transmitting one packet, the BA window may not be advanced and the BA window may get depleted because the BA from the slow link has not been received yet. Consequently, the fast link may become unable to transmit further due to the BA window running out.

[0023] When a particular link has a high packet error rate (PER) and some MPDUs consistently fail and need to be retransmitted, the BA window is unable to progress, preventing transmission of packets with higher sequence numbers (SNs). As a result, even a link with good channel metrics (e.g., low PER) may eventually be unable to transmit due to the BA window running out.

[0024] Another problem with using a same AMPDU limit on multiple links is that peak throughput may be difficult to achieve, as the AMPDU limit may need to be reduced for a link with smaller bandwidth (to an AMPDU limit that is sub-optimal for the higher bandwidth link). Other issues may arise when dealing with medium or long-range scenarios (in terms of transmission distance over the links), where an achievable physical layer (PHY) rate may not be high, and PER tends to increase. In such cases, it may also be desirable to dynamically reduce the AMPDU limit (cap) to prevent the rapid depletion of the BA window due to PER, while still maintaining satisfactory medium access control (MAC) layer efficiency.

[0025] Aspects of the present disclosure, however, may help address these issues by utilizing dynamically allocated AMPDUs for different links based on specific scenarios. For example, a wireless node (communicating via multiple links with another wireless node) may allocate a first AMPDU size to a first wireless link and a second AMPDU size to a second wireless link, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link.

[0026] As a result, aspects of the present disclosure may help avoid the scenarios described above, where asymmetrical link characteristics prevent one link from transmitting due to issues on another link, which may result in increased resource performance and overall improved user experience.EXAMPLE WIRELESS COMMUNICATION NETWORK

[0027] Figure 1 shows a pictorial diagram of an example wireless communication network 100. According to some aspects, the wireless communication network 100 can be an example of a wireless local area network (WLAN) such as a Wi-Fi network. For example, the wireless communication network 100 can be a network implementing at least one of the IEEE 802.11 family of wireless communication protocol standards (such as defined by the IEEE 802.11-2020 specification or amendments thereof including, but not limited to, 802.11ay, 802.11ax, 802.11az, 802.11ba, 802.11bd, 802.11be, 802.11bf, and 802.11bn). In some other examples, the wireless communication network 100 can be an example of a cellular radio access network (RAN), such as a 5G or 6G RAN that implements one or more cellular protocols such as those specified in one or more 3GPP standards. In some other examples, the wireless communication network 100 can include a WLAN that functions in an interoperable or converged manner with one or more cellular RANs to provide greater or enhanced network coverage to wireless communication devices within the wireless communication network 100 or to enable such devices to connect to a cellular network’s core, such as to access the network management capabilities and functionality offered by the cellular network core.

[0028] The wireless communication network 100 may include numerous wireless communication devices including at least one wireless access point (AP) 102 and any number of wireless stations (STAs) 104. While only one AP 102 is shown in Figure 1, the wireless communication network 100 can include multiple APs 102. The AP 102 can be or represent various different types of network entities including, but not limited to, a home networking AP, an enterprise-level AP, a single-frequency AP, a dual-bandsimultaneous (DBS) AP, a tri -band simultaneous (TBS) AP, a standalone AP, a non- standalone AP, a software-enabled AP (soft AP), and a multi-link AP (also referred to as an AP multi-link device (MLD)), as well as cellular (such as 3GPP, 4G LTE, 5G or 6G) base stations or other cellular network nodes such as a Node B, an evolved Node B (eNB), a gNB, a transmission reception point (TRP) or another type of device or equipment included in a radio access network (RAN), including Open-RAN (O-RAN) network entities, such as a central unit (CU), a distributed unit (DU) or a radio unit (RU).

[0029] Each of the STAs 104 also may be referred to as a mobile station (MS), a mobile device, a mobile handset, a wireless handset, an access terminal (AT), a user equipment (UE), a subscriber station (SS), or a subscriber unit, among other examples. The STAs 104 may represent various devices such as mobile phones, other handheld or wearable communication devices, netbooks, notebook computers, tablet computers, laptops, Chromebooks, augmented reality (AR), virtual reality (VR), mixed reality (MR) or extended reality (XR) wireless headsets or other peripheral devices, wireless earbuds, other wearable devices, display devices (for example, TVs, computer monitors or video gaming consoles), video game controllers, navigation systems, music or other audio or stereo devices, remote control devices, printers, kitchen appliances (including smart refrigerators) or other household appliances, key fobs (for example, for passive keyless entry and start (PKES) systems), Internet of Things (loT) devices, and vehicles, among other examples.

[0030] A single AP 102 and an associated set of STAs 104 may be referred to as a basic service set (BSS), which is managed by the respective AP 102. Figure 1 additionally shows an example coverage area 108 of the AP 102, which may represent a basic service area (BSA) of the wireless communication network 100. The BSS may be identified by STAs 104 and other devices by a service set identifier (SSID), as well as a basic service set identifier (BSSID), which may be a medium access control (MAC) address of the AP 102. The AP 102 may periodically broadcast beacon frames (“beacons”) including the BSSID to enable any STAs 104 within wireless range of the AP 102 to “associate” or reassociate with the AP 102 to establish a respective communication link 106 (hereinafter also referred to as a “Wi-Fi link”), or to maintain a communication link 106, with the AP 102. For example, the beacons can include an identification or indication of a primary channel used by the respective AP 102 as well as a timing synchronization function (TSF) for establishing or maintaining timing synchronization with the AP 102. The AP 102 mayprovide access to external networks to various STAs 104 in the wireless communication network 100 via respective communication links 106.

[0031] To establish a communication link 106 with an AP 102, each of the STAs 104 is configured to perform passive or active scanning operations (“scans”) on frequency channels in one or more frequency bands (for example, the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, or 60 GHz bands). To perform passive scanning, a STA 104 listens for beacons, which are transmitted by respective APs 102 at periodic time intervals referred to as target beacon transmission times (TBTTs). To perform active scanning, a STA 104 generates and sequentially transmits probe requests on each channel to be scanned and listens for probe responses from APs 102. Each STA 104 may identify, determine, ascertain, or select an AP 102 with which to associate in accordance with the scanning information obtained through the passive or active scans, and to perform authentication and association operations to establish a communication link 106 with the selected AP 102. The selected AP 102 assigns an association identifier (AID) to the STA 104 at the culmination of the association operations, which the AP 102 uses to track the STA 104.

[0032] As a result of the increasing ubiquity of wireless networks, a STA 104 may have the opportunity to select one of many BSSs within range of the STA 104 or to select among multiple APs 102 that together form an extended service set (ESS) including multiple connected BSSs. For example, the wireless communication network 100 may be connected to a wired or wireless distribution system that may enable multiple APs 102 to be connected in such an ESS. As such, a STA 104 can be covered by more than one AP 102 and can associate with different APs 102 at different times for different transmissions. Additionally, after association with an AP 102, a STA 104 also may periodically scan its surroundings to find a more suitable AP 102 with which to associate. For example, a STA 104 that is moving relative to its associated AP 102 may perform a “roaming” scan to find another AP 102 having more desirable network characteristics such as a greater received signal strength indicator (RS SI) or a reduced traffic load.

[0033] In some cases, STAs 104 may form networks without APs 102 or other equipment other than the STAs 104 themselves. One example of such a network is an ad hoc network (or wireless ad hoc network). Ad hoc networks may alternatively be referred to as mesh networks or peer-to-peer (P2P) networks. In some cases, ad hoc networks may be implemented within a larger network such as the wireless communication network 100. In such examples, while the STAs 104 may be capable of communicating with each other through the AP 102 using communication links 106, STAs 104 also cancommunicate directly with each other via direct wireless communication links 110. Additionally, two STAs 104 may communicate via a direct communication link 110 regardless of whether both STAs 104 are associated with and served by the same AP 102. In such an ad hoc system, one or more of the STAs 104 may assume the role filled by the AP 102 in a BSS. Such a STA 104 may be referred to as a group owner (GO) and may coordinate transmissions within the ad hoc network. Examples of direct wireless communication links 110 include Wi-Fi Direct connections, connections established by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, and other P2P group connections.

[0034] In some networks, the AP 102 or the STAs 104, or both, may support applications associated with high throughput or low-latency requirements, or may provide lossless audio to one or more other devices. For example, the AP 102 or the STAs 104 may support applications and use cases associated with ultra-low-latency (ULL), such as ULL gaming, or streaming lossless audio and video to one or more personal audio devices (such as peripheral devices) or AR / VR / MR / XR headset devices. In scenarios in which a user uses two or more peripheral devices, the AP 102 or the STAs 104 may support an extended personal audio network enabling communication with the two or more peripheral devices. Additionally, the AP 102 and STAs 104 may support additional ULL applications such as cloud-based applications (such as VR cloud gaming) that have ULL and high throughput requirements.

[0035] As indicated above, in some implementations, the AP 102 and the STAs 104 may function and communicate (via the respective communication links 106) according to one or more of the IEEE 802.11 family of wireless communication protocol standards. These standards define the WLAN radio and baseband protocols for the physical (PHY) and MAC layers. The AP 102 and STAs 104 transmit and receive wireless communications (hereinafter also referred to as “Wi-Fi communications” or “wireless packets”) to and from one another in the form of PHY protocol data units (PPDUs).

[0036] Each PPDU is a composite structure that includes a PHY preamble and a payload that is in the form of a PHY service data unit (PSDU). The information provided in the preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which a PPDU is transmitted over a bonded or wideband channel, the preamble fields may be duplicated and transmitted in each of multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses.The legacy preamble also may generally be used to maintain compatibility with legacy devices. The format of, coding of, and information provided in the non-legacy portion of the preamble is associated with the particular IEEE 802.11 wireless communication protocol to be used to transmit the payload.

[0037] The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over an unlicensed spectrum, which may be a portion of spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 2.4 GHz, 5 GHz, 6 GHz, 45 GHz, and 60 GHz bands. Some examples of the APs 102 and STAs 104 described herein also may communicate in other frequency bands that may support licensed or unlicensed communications. For example, the APs 102 or STAs 104, or both, also may be capable of communicating over licensed operating bands, where multiple operators may have respective licenses to operate in the same or overlapping frequency ranges. Such licensed operating bands may map to or be associated with frequency range designations of FR1 (410 MHz - 7.125 GHz), FR2 (24.25 GHz - 52.6 GHz), FR3 (7.125 GHz - 24.25 GHz), FR4a or FR4-1 (52.6 GHz - 71 GHz), FR4 (52.6 GHz - 114.25 GHz), and FR5 (114.25 GHz - 300 GHz).

[0038] Each of the frequency bands may include multiple sub-bands and frequency channels (also referred to as subchannels). For example, PPDUs conforming to the IEEE 802.1 In, 802.1 lac, 802.1 lax, 802.11be and 802.11bn standard amendments may be transmitted over one or more of the 2.4 GHz, 5 GHz, or 6 GHz bands, each of which is divided into multiple 20 MHz channels. As such, these PPDUs are transmitted over a physical channel having a minimum bandwidth of 20 MHz, but larger channels can be formed through channel bonding. For example, PPDUs may be transmitted over physical channels having bandwidths of 40 MHz, 80 MHz, 160 MHz, 240 MHz, 320 MHz, 480 MHz, or 640 MHz by bonding together multiple 20 MHz channels.

[0039] Each PPDU is a composite structure that includes a PHY preamble and a payload in the form of a PHY service data unit (PSDU). The information provided in the preamble may be used by a receiving device to decode the subsequent data in the PSDU. In instances in which PPDUs are transmitted over a bonded channel, the preamble fields may be duplicated and transmitted in each of the multiple component channels. The PHY preamble may include both a legacy portion (or “legacy preamble”) and a non-legacy portion (or “non-legacy preamble”). The legacy preamble may be used for packet detection, automatic gain control and channel estimation, among other uses. The legacy preamble also may generally be used to maintain compatibility with legacy devices. Theformat of, coding of, and information provided in the non-legacy portion of the preamble is associated with the particular IEEE 802.11 protocol to be used to transmit the payload

[0040] Figure 2 shows an example protocol data unit (PDU) 200 usable for wireless communication between a wireless AP 102 and one or more wireless STAs 104. For example, the PDU 200 can be configured as a PPDU. As shown, the PDU 200 includes a PHY preamble 202 and a PHY payload 204. For example, the preamble 202 may include a legacy portion that itself includes a legacy short training field (L-STF) 206, which may consist of two symbols, a legacy long training field (L-LTF) 208, which may consist of two symbols, and a legacy signal field (L-SIG) 210, which may consist of two symbols. The legacy portion of the preamble 202 may be configured according to the IEEE 802. I la wireless communication protocol standard. The preamble 202 also may include a nonlegacy portion including one or more non-legacy fields 212, for example, conforming to one or more of the IEEE 802.11 family of wireless communication protocol standards.

[0041] The L-STF 206 generally enables a receiving device to perform coarse timing and frequency tracking and automatic gain control (AGC). The L-LTF 208 generally enables a receiving device to perform fine timing and frequency tracking and also to perform an initial estimate of the wireless channel. The L-SIG 210 generally enables a receiving device to determine (for example, obtain, select, identify, detect, ascertain, calculate, or compute) a duration of the PDU and to use the determined duration to avoid transmitting on top of the PDU. The legacy portion of the preamble, including the L-STF 206, the L-LTF 208 and the L-SIG 210, may be modulated according to a binary phase shift keying (BPSK) modulation scheme. The payload 204 may be modulated according to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK) modulation scheme, a quadrature amplitude modulation (QAM) modulation scheme, or another appropriate modulation scheme. The payload 204 may include a PSDU including a data field (DATA) 214 that, in turn, may carry higher layer data, for example, in the form of MAC protocol data units (MPDUs) or an aggregated MPDU (A-MPDU).

[0042] Figure 3 shows a hierarchical format of an example PPDU usable for communications between a wireless AP 102 and one or more wireless STAs 104. As described, each PPDU 300 includes a PHY preamble 302 and a PSDU 304. Each PSDU 304 may represent (or “carry”) one or more MAC protocol data units (MPDUs) 316. For example, each PSDU 304 may carry an aggregated MPDU (A-MPDU) 306 that includes an aggregation of multiple A-MPDU subframes 308. Each A-MPDU subframe 306 may include an MPDU frame 310 that includes a MAC delimiter 312 and a MAC header 314prior to the accompanying MPDU 316, which includes the data portion (“payload” or “frame body”) of the MPDU frame 310. Each MPDU frame 310 also may include a frame check sequence (FCS) field 318 for error detection (for example, the FCS field may include a cyclic redundancy check (CRC)) and padding bits 320. The MPDU 316 may carry one or more MAC service data units (MSDUs) 316. For example, the MPDU 316 may carry an aggregated MSDU (A-MSDU) 322 including multiple A-MSDU subframes 324. Each A-MSDU subframe 324 contains a corresponding MSDU 330 preceded by a subframe header 328 and in some cases followed by padding bits 332.

[0043] Referring back to the MPDU frame 310, the MAC delimiter 312 may serve as a marker of the start of the associated MPDU 316 and indicate the length of the associated MPDU 316. The MAC header 314 may include multiple fields containing information that defines or indicates characteristics or attributes of data encapsulated within the frame body 316. The MAC header 314 includes a duration field indicating a duration extending from the end of the PPDU until at least the end of an acknowledgment (ACK) or Block ACK (BA) of the PPDU that is to be transmitted by the receiving wireless communication device. The use of the duration field serves to reserve the wireless medium for the indicated duration, and enables the receiving device to establish its network allocation vector (NAV). The MAC header 314 also includes one or more fields indicating addresses for the data encapsulated within the frame body 316. For example, the MAC header 314 may include a combination of a source address, a transmitter address, a receiver address or a destination address. The MAC header 314 may further include a frame control field containing control information. The frame control field may specify a frame type, for example, a data frame, a control frame, or a management frame.

[0044] Some APs and STAs may implement techniques for spatial reuse that involve participation in a coordinated communication scheme. According to such techniques, an AP may contend for access to a wireless medium to obtain control of the medium for a TXOP. The AP that wins the contention (hereinafter also referred to as a “sharing AP”) may select one or more other APs (hereinafter also referred to as “shared APs”) to share resources of the TXOP. The sharing and shared APs may be located in proximity to one another such that at least some of their wireless coverage areas at least partially overlap. Some examples may specifically involve coordinated AP TDMA or OFDMA techniques for sharing the time or frequency resources of a TXOP. To share its time or frequency resources, the sharing AP may partition the TXOP into multiple time segments or frequency segments each including respective time or frequency resources representing aportion of the TXOP, The sharing AP may allocate the time or frequency segments to itself or to one or more of the shared APs. For example, each shared AP may utilize a partial TXOP assigned by the sharing AP for its uplink or downlink communications with its associated STAs.

[0045] In some examples of such TDMA techniques, each portion of a plurality of portions of the TXOP includes a set of time resources that do not overlap with any time resources of any other portion of the plurality of portions. In such examples, the scheduling information may include an indication of time resources, of multiple time resources of the TXOP, associated with each portion of the TXOP. For example, the scheduling information may include an indication of a time segment of the TXOP such as an indication of one or more slots or sets of symbol periods associated with each portion of the TXOP such as for multi-user TDMA.

[0046] In some other examples of OFDMA techniques, each portion of the plurality of portions of the TXOP includes a set of frequency resources that do not overlap with any frequency resources of any other portion of the plurality of portions. In such implementations, the scheduling information may include an indication of frequency resources, of multiple frequency resources of the TXOP, associated with each portion of the TXOP. For example, the scheduling information may include an indication of a bandwidth portion of the wireless channel such as an indication of one or more subchannels or resource units (RUs) associated with each portion of the TXOP such as for multi-user OFDMA.

[0047] In this manner, the sharing AP’s acquisition of the TXOP enables communication between one or more additional shared APs and their respective BSSs, subject to appropriate power control and link adaptation. For example, the sharing AP may limit the transmit powers of the selected shared APs such that interference from the selected APs does not prevent STAs associated with the TXOP owner from successfully decoding packets transmitted by the sharing AP. Such techniques may be used to reduce latency because the other APs may not need to wait to win contention for a TXOP to be able to transmit and receive data according to conventional CSMA / CA or EDCA techniques. Additionally, by enabling a group of APs associated with different BSSs to participate in a coordinated AP transmission session, during which the group of APs may share at least a portion of a single TXOP obtained by any one of the participating APs, such techniques may increase throughput across the BSSs associated with the participating APs and may also achieve improvements in throughput fairness.Furthermore, with appropriate selection of the shared APs and the scheduling of their respective time or frequency resources, medium utilization may be maximized or otherwise increased while packet loss resulting from OBSS interference is minimized or otherwise reduced. Various implementations may achieve these and other advantages without requiring that the sharing AP or the shared APs be aware of the STAs associated with other BSSs, without requiring a preassigned or dedicated master AP or preassigned groups of APs, and without requiring backhaul coordination between the APs participating in the TXOP.

[0048] In some examples in which the signal strengths or levels of interference associated with the selected APs are relatively low (such as less than a given value), or when the decoding error rates of the selected APs are relatively low (such as less than a threshold), the start times of the communications among the different BSSs may be synchronous. Conversely, when the signal strengths or levels of interference associated with the selected APs are relatively high (such as greater than the given value), or when the decoding error rates of the selected APs are relatively high (such as greater than the threshold), the start times may be offset from one another by a time period associated with decoding the preamble of a wireless packet and determining, from the decoded preamble, whether the wireless packet is an intra-BSS packet or is an OBSS packet. For example, the time period between the transmission of an intra-BSS packet and the transmission of an OBSS packet may allow a respective AP (or its associated STAs) to decode the preamble of the wireless packet and obtain the BSS color value carried in the wireless packet to determine whether the wireless packet is an intra-BSS packet or an OBSS packet. In this manner, each of the participating APs and their associated STAs may be able to receive and decode intra-BSS packets in the presence of OBSS interference.

[0049] In some examples, the sharing AP may perform polling of a set of un-managed or non-co-managed APs that support coordinated reuse to identify candidates for future spatial reuse opportunities. For example, the sharing AP may transmit one or more spatial reuse poll frames as part of determining one or more spatial reuse criteria and selecting one or more other APs to be shared APs. According to the polling, the sharing AP may receive responses from one or more of the polled APs. In some specific examples, the sharing AP may transmit a coordinated AP TXOP indication (CTI) frame to other APs that indicates time and frequency of resources of the TXOP that can be shared. The sharing AP may select one or more candidate APs upon receiving a coordinated AP TXOP request (CTR) frame from a respective candidate AP that indicates a desire by therespective AP to participate in the TXOP. The poll responses or CTR frames may include a power indication, for example, an RX power or RSSI measured by the respective AP. In some other examples, the sharing AP may directly measure potential interference of a service supported (such as UL transmission) at one or more APs, and select the shared APs based on the measured potential interference. The sharing AP generally selects the APs to participate in coordinated spatial reuse such that it still protects its own transmissions (which may be referred to as primary transmissions) to and from the STAs in its BSS. The selected APs may then be allocated resources during the TXOP as described above.

[0050] Retransmission protocols, such as hybrid automatic repeat request (HARQ), also may offer performance gains. A HARQ protocol may support various HARQ signaling between transmitting and receiving wireless communication devices as well as signaling between the PHY and MAC layers to improve the retransmission operations in a WLAN. HARQ uses a combination of error detection and error correction. For example, a HARQ transmission may include error checking bits that are added to data to be transmitted using an error-detecting (ED) code, such as a cyclic redundancy check (CRC). The error checking bits may be used by the receiving device to determine if it has properly decoded the received HARQ transmission. In some examples, the original data (information bits) to be transmitted may be encoded with a forward error correction (FEC) code, such as using a low-density parity check (LDPC) coding scheme that systematically encodes the information bits to produce parity bits. The transmitting device may transmit both the original information bits as well as the parity bits in the HARQ transmission to the receiving device. The receiving device may be able to use the parity bits to correct errors in the information bits, thus avoiding a retransmission.

[0051] Implementing a HARQ protocol in a WLAN may improve reliability of data communicated from a transmitting device to a receiving device. The HARQ protocol may support the establishment of a HARQ session between the two devices. Once a HARQ session is established, If a receiving device cannot properly decode (and cannot correct the errors) a first HARQ transmission received from the transmitting device, the receiving device may transmit a HARQ feedback message to the transmitting device (for example, a negative acknowledgement (NACK)) that indicates at least part of the first HARQ transmission was not properly decoded. Such a HARQ feedback message may be different than the traditional Block ACK feedback message type associated with conventional ARQ. In response to receiving the HARQ feedback message, thetransmitting device may transmit a second HARQ transmission to the receiving device to communicate at least part of further assist the receiving device in decoding the first HARQ transmission. For example, the transmitting device may include some or all of the original information bits, some or all of the original parity bits, as well as other, different parity bits in the second HARQ transmission. The combined HARQ transmissions may be processed for decoding and error correction such that the complete signal associated with the HARQ transmissions can be obtained.

[0052] In some examples, the receiving device may be enabled to control whether to continue the HARQ process or revert to a non-HARQ retransmission scheme (such as an ARQ protocol). Such switching may reduce feedback overhead and increase the flexibility for retransmissions by allowing devices to dynamically switch between ARQ and HARQ protocols during frame exchanges. Some implementations also may allow multiplexing of communications that employ ARQ with those that employ HARQ.

[0053] Some wireless communication devices (including both APs and STAs) are capable of multi-link operation (MLO). In some examples, MLO supports establishing multiple different communication links (such as a first link on the 2.4 GHz band, a second link on the 5 GHz band, and the third link on the 6 GHz band) between the STA and the AP. Each communication link may support one or more sets of channels or logical entities. In some cases, each communication link associated with a given wireless communication device may be associated with a respective radio of the wireless communication device, which may include one or more transmit / receive (Tx / Rx) chains, include or be coupled with one or more physical antennas, or include signal processing components, among other components. An MLO-capable device may be referred to as a multi-link device (MLD). For example, an AP MLD may include multiple APs each configured to communicate on a respective communication link with a respective one of multiple STAs of a non-AP MLD (also referred to as a “STA MLD”). The STA MLD may communicate with the AP MLD over one or more of the multiple communication links at a given time.

[0054] One type of MLO is multi-link aggregation (MLA), where traffic associated with a single STA is simultaneously transmitted across multiple communication links in parallel to maximize the utilization of available resources to achieve higher throughput. That is, during at least some duration of time, transmissions or portions of transmissions may occur over two or more links in parallel at the same time. In some examples, the parallel wireless communication links may support synchronized transmissions. In someother examples, or during some other durations of time, transmissions over the links may be parallel, but not be synchronized or concurrent. In some examples or durations of time, two or more of the links may be used for communications between the wireless communication devices in the same direction (such as all uplink or all downlink). In some other examples or durations of time, two or more of the links may be used for communications in different directions. For example, one or more links may support uplink communications and one or more links may support downlink communications. In such examples, at least one of the wireless communication devices operates in a full duplex mode. Generally, full duplex operation enables bi-directional communications where at least one of the wireless communication devices may transmit and receive at the same time.

[0055] MLA may be implemented in a number of ways. In some examples, MLA may be packet-based. For packet-based aggregation, frames of a single traffic flow (such as all traffic associated with a given traffic identifier (TID)) may be sent concurrently across multiple communication links. In some other examples, MLA may be flow-based. For flow-based aggregation, each traffic flow (such as all traffic associated with a given TID) may be sent using a single one of multiple available communication links. As an example, a single STA MLD may access a web browser while streaming a video in parallel. The traffic associated with the web browser access may be communicated over a first communication link while the traffic associated with the video stream may be communicated over a second communication link in parallel (such that at least some of the data may be transmitted on the first channel concurrently with data transmitted on the second channel).

[0056] In some other examples, MLA may be implemented as a hybrid of flow-based and packet-based aggregation. For example, an MLD may employ flow-based aggregation in situations in which multiple traffic flows are created and may employ packet-based aggregation in other situations. The determination to switch among the MLA techniques or modes may additionally or alternatively be associated with other metrics (such as a time of day, traffic load within the network, or battery power for a wireless communication device, among other factors or considerations).

[0057] To support MLO techniques, an AP MLD and a STA MLD may exchange supported MLO capability information (such as supported aggregation type or supported frequency bands, among other information). In some examples, the exchange of information may occur via a beacon signal, a probe request or probe response, anassociation request or an association response frame, a dedicated action frame, or an operating mode indicator (OMI), among other examples. In some examples, an AP MLD may designate a given channel in a given band as an anchor channel (such as the channel on which it transmits beacons and other management frames). In such examples, the AP MLD also may transmit beacons (such as ones which may contain less information) on other channels for discovery purposes.

[0058] MLO techniques may provide multiple benefits to a WLAN. For example, MLO may improve user perceived throughput (UPT) (such as by quickly flushing peruser transmit queues). Similarly, MLO may improve throughput by improving utilization of available channels and may increase spectral utilization (such as increasing the bandwidth-time product). Further, MLO may enable smooth transitions between multiband radios (such as where each radio may be associated with a given RF band) or enable a framework to set up separation of control channels and data channels. Other benefits of MLO include reducing the ON time of a modem, which may benefit a wireless communication device in terms of power consumption. Another benefit of MLO is the increased multiplexing opportunities in the case of a single BSS. For example, multi-link aggregation may increase the number of users per multiplexed transmission served by the multi-link AP MLD.

[0059] Figure 4 shows a pictorial diagram of another example wireless communication network 400. According to some aspects, the wireless communication network 400 can be an example of a mesh network, an loT network or a sensor network in accordance with one or more of the IEEE 802.11 family of wireless communication protocol standards (including the 802.11 ah amendment). The wireless network 400 may include multiple wireless communication devices 414. The wireless communication devices 414 may represent various devices such as display devices (for example, TVs, computer monitors, navigation systems, among others), music or other audio or stereo devices, remote control devices (“remotes”), printers, kitchen or other household appliances, among other examples.

[0060] In some examples, the wireless communication devices 414 sense, measure, collect or otherwise obtain and process data and then transmit such raw or processed data to an intermediate device 412 for subsequent processing or distribution. Additionally or alternatively, the intermediate device 412 may transmit control information, digital content (for example, audio or video data), configuration information or other instructions to the wireless communication devices 414. The intermediate device 412 and the wirelesscommunication devices 414 can communicate with one another via wireless communication links 416. In some examples, the wireless communication links 416 include Bluetooth links or other PAN or short-range communication links.

[0061] In some examples, the intermediate device 412 also may be configured for wireless communication with other networks such as with a Wi-Fi WLAN 100 or a wireless (for example, cellular) wide area network (WWAN), which may, in turn, provide access to external networks including the Internet. For example, the intermediate device 412 may associate and communicate, over a Wi-Fi link 418, with an AP 402 of a WLAN network, which also may serve various STAs 404. In some examples, the intermediate device 412 is an example of a network gateway, for example, an loT gateway. In such a manner, the intermediate device 412 may serve as an edge network bridge providing a Wi-Fi core backhaul for the loT network including the wireless communication devices 414. In some examples, the intermediate device 412 can analyze, preprocess and aggregate data received from the wireless communication devices 414 locally at the edge before transmitting it to other devices or external networks via the Wi-Fi link 418. The intermediate device 412 also can provide additional security for the loT network and the data it transports.

[0062] Some wireless communication devices (including both APs and STAs) are capable of multi-link operation (MLO). In some examples, MLO supports establishing multiple different communication links (such as a first link on the 2.4 GHz band, a second link on the 5 GHz band, and the third link on the 6 GHz band) between the STA and the AP. Each communication link may support one or more sets of channels or logical entities. In some cases, each communication link associated with a given wireless communication device may be associated with a respective radio of the wireless communication device, which may include one or more transmit / receive (Tx / Rx) chains, include or be coupled with one or more physical antennas, or include signal processing components, among other components. An MLO-capable device may be referred to as a multi-link device (MLD). For example, an AP MLD may include multiple APs each configured to communicate on a respective communication link with a respective one of multiple STAs of a non-AP MLD (also referred to as a “STA MLD”). The STA MLD may communicate with the AP MLD over one or more of the multiple communication links at a given time.

[0063] One type of MLO is multi-link aggregation (MLA), where traffic associated with a single STA is simultaneously transmitted across multiple communication links inparallel to maximize the utilization of available resources to achieve higher throughput. That is, during at least some duration of time, transmissions or portions of transmissions may occur over two or more links in parallel at the same time. In some examples, the parallel wireless communication links may support synchronized transmissions. In some other examples, or during some other durations of time, transmissions over the links may be parallel, but not be synchronized or concurrent. In some examples or durations of time, two or more of the links may be used for communications between the wireless communication devices in the same direction (such as all uplink or all downlink). In some other examples or durations of time, two or more of the links may be used for communications in different directions. For example, one or more links may support uplink communications and one or more links may support downlink communications. In such examples, at least one of the wireless communication devices operates in a full duplex mode. Generally, full duplex operation enables bi-directional communications where at least one of the wireless communication devices may transmit and receive at the same time.

[0064] MLA may be implemented in a number of ways. In some examples, MLA may be packet-based. For packet-based aggregation, frames of a single traffic flow (such as all traffic associated with a given traffic identifier (TID)) may be sent concurrently across multiple communication links. In some other examples, MLA may be flow-based. For flow-based aggregation, each traffic flow (such as all traffic associated with a given TID) may be sent using a single one of multiple available communication links. As an example, a single STA MLD may access a web browser while streaming a video in parallel. The traffic associated with the web browser access may be communicated over a first communication link while the traffic associated with the video stream may be communicated over a second communication link in parallel (such that at least some of the data may be transmitted on the first channel concurrently with data transmitted on the second channel).

[0065] In some other examples, MLA may be implemented as a hybrid of flow-based and packet-based aggregation. For example, an MLD may employ flow-based aggregation in situations in which multiple traffic flows are created and may employ packet-based aggregation in other situations. The determination to switch among the MLA techniques or modes may additionally or alternatively be associated with other metrics (such as a time of day, traffic load within the network, or battery power for a wireless communication device, among other factors or considerations).

[0066] To support MLO techniques, an AP MLD and a STA MLD may exchange supported MLO capability information (such as supported aggregation type or supported frequency bands, among other information). In some examples, the exchange of information may occur via a beacon signal, a probe request or probe response, an association request or an association response frame, a dedicated action frame, or an operating mode indicator (OMI), among other examples. In some examples, an AP MLD may designate a given channel in a given band as an anchor channel (such as the channel on which it transmits beacons and other management frames). In such examples, the AP MLD also may transmit beacons (such as ones which may contain less information) on other channels for discovery purposes.

[0067] MLO techniques may provide multiple benefits to a WLAN. For example, MLO may improve user perceived throughput (UPT) (such as by quickly flushing peruser transmit queues). Similarly, MLO may improve throughput by improving utilization of available channels and may increase spectral utilization (such as increasing the bandwidth-time product). Further, MLO may enable smooth transitions between multiband radios (such as where each radio may be associated with a given RF band) or enable a framework to set up separation of control channels and data channels. Other benefits of MLO include reducing the ON time of a modem, which may benefit a wireless communication device in terms of power consumption. Another benefit of MLO is the increased multiplexing opportunities in the case of a single BSS. For example, multi-link aggregation may increase the number of users per multiplexed transmission served by the multi-link AP MLD.EXAMPLE DYNAMIC AMPDU ALLOCATION FOR MLO

[0068] As noted above, some communication systems utilize multiple links that can have asymmetric characteristics. The asymmetric link characteristics may pose certain practical challenges that could significantly impact performance. For example, if the system utilizes a multi-link transmission protocol that uses a shared packet numbering space, asymmetric link characteristics may result in traffic on two different paths with unequal transfer functions. As a result, packets may be processed at different rates, which may impact performance due to ordering rules with number allocation particularly when each link is assigned a same AMDPU limit (that dictates a limit on AMPDU size / quantity of MPDUs in an AMPDU).

[0069] Such rules may dictate that packets with sequence numbers within a window or range of sequence numbers (e.g., a block acknowledgement or BA window) with aconfigured size must be processed before advancing window to process additional packets. Thus, if two links share a common sequence number space and one link is faster than the other (e.g., due to greater bandwidth), in cases where the faster link successfully completes transmission of multiple packets while the slower link is still transmitting one packet, the BA window may not be advanced and the BA window may get depleted because the BA from the slow link has not been received yet. Consequently, the fast link may become unable to transmit further due to the BA window running out, as illustrated in Figure 5.

[0070] Figure 5 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized. The illustrated example assumes a procedure of transmitting / releasing MPDUs as in a single link operation, with each link assigned the same AMPDU limit, without the dynamic AMPDU allocation proposed herein.

[0071] Since multiple links share the same BA window, certain situations arise which can lead to overall throughput impact despite having multiple links to transact on. For example, when there is big difference between capacity of two links, due to the multiple links sharing a single BA, the slow link may starve the fast link when the AMPDU cap on the two links are the same. In the illustrated example, the fast link is the 320 MHz Link 1, while the slow link is the 80 MHz Link 2.

[0072] The illustrated example assumes a 512 block acknowledgment (BA) window size (512-BA), with four spatial streams (NSS = 4), a modulation and coding scheme (MCS) of 13, and an AMPDU size of 128 (AMPDU = 128). On 320 MHz Link 1, the PPDU duration 512 is approximately 1 ms, and on 80MHz, the PPDU duration 514 is approximately 4ms.

[0073] Given the same AMPDU size of 128 on each link, transmission of multiple PPDUs (with sequence numbers 129-512) on the faster Link 1 may complete before the first transmission on the slower Link 1 (with sequence numbers 1-128). As indicated at 516, this may result in depletion of the BA window, preventing additional transmission on the faster link.

[0074] As noted above, asymmetrical PER on different links may also result in the BA window being unable to progress. As a result, even a link with good channel metrics (e.g., low PER) may eventually be unable to transmit due to the BA window running out, as illustrated in Figure 6.

[0075] Figure 6 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized to address the impact of asymmetrical PER. Theillustrated example again assumes a procedure of transmitting / releasing MPDUs as in a single link operation, with each link assigned the same AMPDU limit, without the dynamic AMPDU allocation proposed herein.

[0076] When one link has higher PER and the MPDUs will be retransmitted over that link for some time, other links may be effectively starved due to the shared BA space. In the illustrated example, the higher PER is on the slower 80 MHz Link 2.

[0077] The illustrated example assumes a 1024 BA window size (1024-BA), with four spatial streams (NSS = 4), a modulation and coding scheme (MCS) of 13, and an AMPDU size of 256 (AMPDU = 256). On the 320 MHz Link 1, the PPDU duration 612 is approximately 2 ms. On the 80MHz Link 2, the PPDU duration 614 is approximately 4ms and can only include 128 AMPDU.

[0078] A higher PER on slower Link 2 can starve the faster Link 1. As shown at 616, the illustrated example assumes a packet error with SN 257. Thus, this corresponding MPDU is subsequently retransmitted, first in a subsequent PPDU with SNs 897-1023. Meanwhile, transmissions on the faster Link 1 successfully transmit SNs 1-256, 285-640, 641-896, and 1024-1279. As indicated at 618, however, the packet error with SN 257 results in depletion of the BA window after SN 1280 on Link 1, preventing additional transmission on the faster link.

[0079] It may be noted that, in general, the PER on one link may starve another link, regardless the capacity of the links, as illustrated in Figure 7. Figure 7 shows an example scenario in which dynamic AMPDU allocation proposed herein may be utilized.

[0080] In the illustrated example, capacity of both Link 1 and Link 2 is 160 MHz. Assuming an AMPDU size of 256 (AMPDU = 256), the PPDU duration (of 712 and 714) is approximately 2 ms on both links. Increased PER on Link 2 can still starve Link 1.

[0081] As shown at 716, the illustrated example assumes a packet error with SN 1. Thus, this corresponding MPDU is subsequently retransmitted, first in a subsequent PPDU with SNs 513-767. Meanwhile, transmissions on the faster Link 1 successfully transmit SNs 257-512 and 768-1023. As indicated at 718, the packet error with SN 1 on Link 2 results in depletion of the BA window, preventing additional transmission on the faster Link 1.

[0082] Asymmetric AMPDU allocation may also present potential challenges. For example, when the two links have the same AMPDU cap size, the AMPDU cap may not be able to fill a longer PPDU (e.g., with a duration >=4ms) for a higher bandwidth (BW) link. As an example, for an AMPDU cap = 256 allocated equally on 2 links, a 4ms PPDUmay not be filled forNSS>=4 and MCS = 13 on a 320MHz link (under certain constraints limiting an aggregated medium access control (MAC) service data unit (AMSDU) byte size 11.5K bytes). In such cases, aspects of the present disclosure may allocate AMPDU size dynamically so that all links can reach a 4ms PPDU, or the prevailing average burst duration which may be continuously monitored.

[0083] As noted above, another potential problem with using a same AMPDU limit on multiple links is that peak throughput may be difficult to achieve, as the AMPDU limit may need to be reduced for a link with smaller bandwidth (to an AMPDU limit that is sub-optimal for the higher bandwidth link). Other issues may arise when dealing with medium or long-range scenarios (in terms of transmission distance over the links), where an achievable physical layer (PHY) rate may not be high, and PER tends to increase. In such cases, it may also be desirable to dynamically reduce the AMPDU limit (cap) to prevent the rapid depletion of the BA window due to PER, while still maintaining satisfactory medium access control (MAC) layer efficiency.

[0084] Aspects of the present disclosure, however, may help address these issues by utilizing dynamically allocate AMPDUs to different links based on specific scenarios. For example, a wireless node (communicating via multiple links with another wireless node) may allocate a first AMPDU size to a first wireless link and a second AMPDU size to a second wireless link, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link.

[0085] As a result, aspects of the present disclosure may help avoid the scenarios described above, where asymmetrical link characteristics prevent one link from transmitting due to issues on another link, which may result in increased resource performance and overall improved user experience.

[0086] The techniques proposed herein may be applied to MLO scenarios, with a sequence number (SN) windowing scheme sending traffic on two different paths of unequal transfer functions due to asymmetrical link characteristics (e.g., different link capacities and / or PERs). While examples described herein refer to wireless MLO scenarios, the techniques proposed herein may be generally applied to any multi-link transmission protocol using a shared packet numbering space that has ordering rules with number allocation. For example, if a multiple link transmission scheme shares a same small transport control protocol (TCP) window, aspects of the present disclosure may apply dynamic TCP sequence number allocation.

[0087] Aspects of the present disclosure dynamically allocate AMPDUs to different links based on specific scenarios. For example, a wireless node (communicating via multiple links with another wireless node) may allocate a first AMPDU size to a first wireless link and a second AMPDU size to a second wireless link, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link.

[0088] According to a first approach, asymmetric AMPDU allocation may be based on static link capacity (of each of the multiple links). This first approach may be suitable, for example, when there is little or no interference. According to this approach, assuming 2 links, the AMPDU cap on each link may be proportional to the link BW as:

[0089] In this manner, a higher BW link may be able to achieve the PPDU duration close to the lower BW link. As a result, the lower BW link may not be able to starve the higher BW link. The high BW link may, thus, be able to achieve a high MAC efficiency associated with using a long PPDU duration.

[0090] In the equation(s) above, the SMALLEST AMPDU may refer to the minimum AMPDU number in a given implementation. The rounding-up to multiple to the SMALLEST AMPDU may help facilitate implementation. The SMALLEST AMPDU can be any number depending on implementation. The parameter F (a factor >=1) generally controls how fast the BA window can be depleted. The value of F may depend on a particular implementation. A typical value of F may be 2, meaning two consecutive full PPDUs can still be sent when BA window is not moving forward.

[0091] According to a second approach, asymmetric AMPDU allocation may be based on a (e.g., continuous) measure of actual capacity (e.g., considering factors such as PER and / or PHY rate). For example, this approach may allow for the AMPDU to be dynamically adjusted for middle and far range scenarios. To achieve this, the equation above may be modified as follows:. , , „ „ .. , .BA Size PHY RATE.AMPDU. = round up( — - i -FX - PHY_RATE1- -+PHY -_ -RATE2, SMALLEST ~ AMPDU);. , , „ „ .. , ,BA Size PHY RATE.AMPDU2= round up( — F - z - v X - PHY_RATE1- -+PHY -_ -RATEZ, SMALLEST ~ AMPDU) (2).

[0092] In these equations, the Phy Rate on each link may depend on a current NSS, MCS, and BW on that link. The MCS / NSS may be affected by measurable parameters,such as receive signal strength indicator (RSSI) and / or PER. For this reason, equation (2) may be more suitable for use in both peak and non-peak performance cases.

[0093] In some cases, if both the links are at midrange (e.g., with MCS7), the ratio of the Phy Rates may be no different than the ratio of Phy Rates at a peak region. In other words, the AMPDU1 and AMPDU2 values may be the same as at the Peak Rate. In some cases, AMPDU allocation may be designed to ensure some PPDU duration of, for example, of x msec (e.g., 4 msec) on each link and at least F number of consecutive PPDUs Tx. In this case, AMPDU allocation may be determined based on the following mapping, assuming links are denoted as Link xl, Link_x2,...Link_xn. The Maximum A- MPDU on Link xl may be denoted as Link xl AMPDU and may be determined as:Min(#MPDUs required to support 4msec PPDU at Peak MCS on Link xl, B A Window Link x 1 ) .The BA Window Link xl may be determined as:(BA / F)*(BW_link_xl / Sum(BW_link_xl +. . . + BW_Link_xn)).

[0094] At any range (e.g., at MCS_z) the #MPDUs used on Link_xl will be Min(Link_xl AMPDU, #MPDUs required to support 4msec PPDU at MCS z Link xl). In some cases, based on the MCS used, the A-MSDU may be adjusted and, in the case of MLO, the same A-MSDU may be used on both the links. In some cases, if the slower link is determining the A-MSDU used (e.g.,, lower A-MSDU), then even on the high speed link, the #MPDUs will be capped to ensure that F number of PPDUs can be sent. In this manner, this model may account for a change in A-MSDU.

[0095] In some cases, considering the issue of a BA window running out due to PER, as discussed above with reference to Figures 6 and 7, the effect of PER on the AMPDU allocation may be considered. For example, in addition to the factors considered in equation (2), AMPDU may be adjusted such that the AMPDU for the link with the higher PER will be reduced. For example, AMPDU allocation may be adjusted based on PER as follows. Assuming AMPDU1> AMPDU2, then AAMPDU = AMPDU - AMPDU2. In this case, when PERI > PER2, AAMPDU may be updated as follows:AMPDUlnew = AMPDUlold + (AAMPDU new- AMPDU old) / 2; andAMPDU2new = AMPDU2old - ( AMPDU new- AMPDU old) / 2 (3).This approach may result in the higher PER link reducing its AMPDU cap, which may result in more efficient transmission on the other link.

[0096] In some cases, rather than just the PER on a link, the actual location of an MPDU that is failing may have an impact. Therefore, according to certain aspects, the location of a packet error within a PPDU may be considered when determining the AMPDU allocation for each link. As the location of the packet error may be directly reflected by a remaining BA window size, one approach is to determine the first and second AMPDU sizes based on the remaining BA window size (which generally equals to the first failed MPDU sequence number + B A size - last transmitted MPDU sequence number. AMPDU allocation based on remaining BA window size may be as follows:

[0097] According to certain aspects, AMSDU size may be dynamically allocated, as an alternative or in addition, to allocating AMPDU to optimize link usage. In this manner, AMSDU size may also be adjusted to handle the asymmetric link characteristics.

[0098] According to certain aspects, one link may be given preference (e.g., higher priority) than the other link for one or more reasons. In such cases, a higher AMPDU cap may be allocated to the preferred link. For example, if a link is preferred by x%, the AMPDU for that link may be adjusted based on the value of x.Example Operations

[0099] FIG. 8 shows an example of a method 800 of wireless communication at a first wireless node. In some examples, the first wireless node is a station, such as a STA 104 of FIGS. 1 and 2. In some examples, the first wireless node is an access point, such as an AP 102 of FIG. 1.

[0100] Method 800 begins at step 805 with establishing at least a first wireless link and a second wireless link with a second wireless node. In some cases, the operations of this step refer to, or may be performed by, circuitry for establishing and / or code for establishing as described with reference to FIG. 9.

[0101] Method 800 then proceeds to step 810 with allocating, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link. In some cases,the operations of this step refer to, or may be performed by, circuitry for allocating and / or code for allocating as described with reference to FIG. 9.

[0102] Method 800 then proceeds to step 815 with communicating with the second wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation. In some cases, the operations of this step refer to, or may be performed by, circuitry for communicating and / or code for communicating as described with reference to FIG. 9

[0103] In some aspects, the first and second wireless links share a common sliding window of sequence numbers.

[0104] In some aspects, asymmetry of the at least one parameter on the first wireless link and on the second wireless link results in asymmetry, on the first wireless link and on the second wireless link, in completion of tasks involving transmission of packets with sequence numbers assigned from the common sliding window.

[0105] In some aspects, the first wireless node is affiliated with a multi-link device (MLD) that comprises an access point (AP) MLD or a non-AP MLD.

[0106] In some aspects, the at least one parameter comprises a link capacity of at least one of the first wireless link or the second wireless link.

[0107] In some aspects, the first AMPDU size is proportional to a bandwidth of the first wireless link; and the second AMPDU size is proportional to a bandwidth of the second wireless link.

[0108] In some aspects, the first AMPDU size is based on a first value proportional to a bandwidth of the first wireless link or a minimum AMPDU size; and the second AMPDU size is based on a second value proportional to a bandwidth of the second wireless link or the minimum AMPDU size.

[0109] In some aspects, each of the first and second values is based on a factor that controls how fast a block acknowledgment (BA) window can be depleted.

[0110] In some aspects, the at least one parameter is based on a measure of capacity of at least one of the first wireless link or the second wireless link.[OHl] In some aspects, the at least one parameter depends on at least one of a quantity of streams, a modulation and coding scheme (MCS) or a bandwidth of at least one of the first wireless link or the second wireless link.

[0112] In some aspects, the allocation is also based on a block acknowledgment (BA) size.

[0113] In some aspects, the method 800 further includes allocating, based on the at least one parameter, a first aggregated medium access control (MAC) service data unit (AMSDU) size to the first wireless link and a second AMSDU size to the second wireless link. In some cases, the operations of this step refer to, or may be performed by, circuitry for allocating and / or code for allocating as described with reference to FIG. 9.

[0114] In some aspects, the first AMSDU size and the second AMSDU size are the same.

[0115] In some aspects, the allocation is also based on a priority of at least one of the first wireless link or the second wireless link.

[0116] In some aspects, the allocation is configured to ensure at least a minimum quantity of consecutive physical layer protocol data units to be transmitted in a transmission duration via at least one of the first wireless link or the second wireless link.

[0117] In some aspects, at least one of the first AMPDU size or the second AMDPU size is allocated based on a modulation and coding scheme (MCS).

[0118] In some aspects, each of the first AMPDU size and the second AMPDU size is based on a remaining block acknowledgment (BA) window size, wherein the remaining BA window size is a function of a location of a first failed MPDU sequence number, a BA size, and a last transmitted MPDU sequence number.

[0119] In one aspect, method 800, or any aspect related to it, may be performed by an apparatus, such as communications device 900 of FIG. 9, which includes various components operable, configured, or adapted to perform the method 800. Communications device 900 is described below in further detail.

[0120] Note that FIG. 8 is just one example of a method, and other methods including fewer, additional, or alternative steps are possible consistent with this disclosure.Example Communications Device (s)

[0121] FIG. 9 depicts aspects of an example communications device 900. In some aspects, communications device 900 is a station, such as a STA 104 described above with respect to FIGS. 1 and 2. In some aspects, communications device 900 is an access point, such as an AP 102 described above with respect to FIG. 1.

[0122] The communications device 900 includes a processing system 905 coupled to the transceiver 955 (e.g., a transmitter and / or a receiver). The transceiver 955 is configured to transmit and receive signals for the communications device 900 via the antenna 960, such as the various signals as described herein. The processing system 905may be configured to perform processing functions for the communications device 900, including processing signals received and / or to be transmitted by the communications device 900.

[0123] The processing system 905 includes one or more processors 910. The one or more processors 910 are coupled to a computer-readable medium / memory 930 via a bus 950. In certain aspects, the computer-readable medium / memory 930 is configured to store instructions (e.g., computer-executable code) that when executed by the one or more processors 910, cause the one or more processors 910 to perform the method 800 described with respect to FIG. 8, or any aspect related to it. Note that reference to a processor performing a function of communications device 900 may include one or more processors 910 performing that function of communications device 900.

[0124] In the depicted example, computer-readable medium / memory 930 stores code (e.g., executable instructions), such as code for establishing 935, code for allocating 940, and code for communicating 945. Processing of the code for establishing 935, code for allocating 940, and code for communicating 945 may cause the communications device 900 to perform the method 800 described with respect to FIG. 8, or any aspect related to it.

[0125] The one or more processors 910 include circuitry configured to implement (e.g., execute) the code stored in the computer-readable medium / memory 930, including circuitry for establishing 915, circuitry for allocating 920, and circuitry for communicating 925. Processing with circuitry for establishing 915, circuitry for allocating 920, and circuitry for communicating 925 may cause the communications device 900 to perform the method 800 described with respect to FIG. 8, or any aspect related to it.

[0126] Various components of the communications device 900 may provide means for performing the method 800 described with respect to FIG. 8, or any aspect related to it. For example, means for transmitting, sending or outputting for transmission may include the transceiver 955 and the antenna 960 of the communications device 900 in FIG. 9. Means for receiving or obtaining may include the transceiver 955 and the antenna 960 of the communications device 900 in FIG. 9. Means for communicating may include the transceiver 955 and the antenna 960 of the communications device 900 in FIG. 9.EXAMPLE CLAUSES

[0127] Implementation examples are described in the following numbered clauses:

[0128] Clause 1 : An method for wireless communication at a first wireless node, comprising: establishing at least a first wireless link and a second wireless link with a second wireless node; allocating, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link; and communicating with the second wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

[0129] Clause 2: The method of Clause 1, wherein the first and second wireless links share a common sliding window of sequence numbers.

[0130] Clause 3: The method of Clause 2, wherein asymmetry of the at least one parameter on the first wireless link and on the second wireless link results in asymmetry, on the first wireless link and on the second wireless link, in completion of tasks involving transmission of packets with sequence numbers assigned from the common sliding window.

[0131] Clause 4: The method of any one of Clauses 1-3, wherein the first wireless node is affiliated with a multi-link device (MLD) that comprises an access point (AP) MLD or a non-AP MLD.

[0132] Clause 5: The method of any one of Clauses 1-4, wherein the at least one parameter comprises a link capacity of at least one of the first wireless link or the second wireless link.

[0133] Clause 6: The method of any one of Clauses 1-5, wherein: the first AMPDU size is proportional to a bandwidth of the first wireless link; and the second AMPDU size is proportional to a bandwidth of the second wireless link.

[0134] Clause 7: The method of any one of Clauses 1-6, wherein: the first AMPDU size is based on a first value proportional to a bandwidth of the first wireless link or a minimum AMPDU size; and the second AMPDU size is based on a second value proportional to a bandwidth of the second wireless link or the minimum AMPDU size.

[0135] Clause 8: The method of Clause 7, wherein each of the first and second values is based on a factor that controls how fast a block acknowledgment (BA) window can be depleted.

[0136] Clause 9: The method of any one of Clauses 1-8, wherein the at least one parameter is based on a measure of capacity of at least one of the first wireless link or the second wireless link.

[0137] Clause 10: The method of any one of Clauses 1-9, wherein the at least one parameter depends on at least one of a quantity of streams, a modulation and coding scheme (MCS) or a bandwidth of at least one of the first wireless link or the second wireless link.

[0138] Clause 11 : The method of any one of Clauses 1-10, wherein the allocation is also based on a block acknowledgment (BA) size.

[0139] Clause 12: The method of any one of Clauses 1-11, further comprising: allocating, based on the at least one parameter, a first aggregated medium access control (MAC) service data unit (AMSDU) size to the first wireless link and a second AMSDU size to the second wireless link.

[0140] Clause 13: The method of Clause 12, wherein the first AMSDU size and the second AMSDU size are the same.

[0141] Clause 14: The method of any one of Clauses 1-13, wherein the allocation is also based on a priority of at least one of the first wireless link or the second wireless link.

[0142] Clause 15: The method of any one of Clauses 1-14, wherein the allocation is configured to ensure at least a minimum quantity of consecutive physical layer protocol data units to be transmitted in a transmission duration via at least one of the first wireless link or the second wireless link.

[0143] Clause 16: The method of Clause 15, wherein at least one of the first AMPDU size or the second AMDPU size is allocated based on a modulation and coding scheme (MCS).

[0144] Clause 17: The method of any one of Clauses 1-16, wherein each of the first AMPDU size and the second AMPDU size is based on a remaining block acknowledgment (BA) window size, wherein the remaining BA window size is a function of a location of a first failed MPDU sequence number, a BA size, and a last transmitted MPDU sequence number.

[0145] Clause 18: An apparatus, comprising: a memory comprising executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform a method in accordance with any one of Clauses 1-17.

[0146] Clause 19: An apparatus, comprising means for performing a method in accordance with any one of Clauses 1-17.

[0147] Clause 20: A non-transitory computer-readable medium comprising executable instructions that, when executed by a processor of an apparatus, cause the apparatus to perform a method in accordance with any one of Clauses 1-17.

[0148] Clause 21 : A computer program product embodied on a computer-readable storage medium comprising code for performing a method in accordance with any one of Clauses 1-17.

[0149] Clause 22: A wireless node, comprising: at least one transceiver; a memory comprising executable instructions; and a processor configured to execute the executable instructions and cause the apparatus to perform a method in accordance with any one of Clauses 1-17, wherein the at least one transceiver is configured to communicate with the second wireless node via the first and second wireless links.ADDITIONAL CONSIDERATIONS

[0150] As used herein, the term “determine” or “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure), inferring, ascertaining, measuring, and the like. Also, “determining” can include receiving (such as receiving information), accessing (such as accessing data stored in memory), transmitting (such as transmitting information) and the like. Also, “determining” can include resolving, selecting, obtaining, choosing, establishing and other such similar actions.

[0151] As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c. As used herein, “or” is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “a or b” may include a only, b only, or a combination of a and b.

[0152] As used herein, “based on” is intended to be interpreted in the inclusive sense, unless otherwise explicitly indicated. For example, “based on” may be used interchangeably with “based at least in part on,” “associated with”, or “in accordance with” unless otherwise explicitly indicated. Specifically, unless a phrase refers to “based on only ‘a,’” or the equivalent in context, whatever it is that is “based on ‘a,’” or “based at least in part on ‘a,’” may be based on “a” alone or based on a combination of “a” and one or more other factors, conditions or information.

[0153] As used herein, “a processor,” “at least one processor” or “one or more processors” generally refers to a single processor configured to perform one or multiple operations or multiple processors configured to collectively perform one or more operations. In the case of multiple processors, performance the one or more operationscould be divided amongst different processors, though one processor may perform multiple operations, and multiple processors could collectively perform a single operation. Similarly, “a memory,” “at least one memory” or “one or more memories” generally refers to a single memory configured to store data and / or instructions, multiple memories configured to collectively store data and / or instructions.

[0154] The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the examples disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

[0155] Various modifications to the examples described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the examples shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0156] Additionally, various features that are described in this specification in the context of separate examples also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple examples separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0157] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes thatare schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the examples described above should not be understood as requiring such separation in all examples, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0158] Means for establishing, means for allocating, and means for communicating may comprise one or more processors, such as one or more of the processors described above with reference to FIG. 9.

Claims

WHAT IS CLAIMED IS:

1. An apparatus for wireless communication, comprising: a memory comprising computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the apparatus to: establish at least a first wireless link and a second wireless link with a wireless node; allocate, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link; and communicate with the wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

2. The apparatus of claim 1, wherein the first and second wireless links share a common sliding window of sequence numbers.

3. The apparatus of claim 2, wherein asymmetry of the at least one parameter on the first wireless link and on the second wireless link results in asymmetry, on the first wireless link and on the second wireless link, in completion of tasks involving transmission of packets with sequence numbers assigned from the common sliding window.

4. The apparatus of claim 1, wherein the apparatus is affiliated with a multi-link device (MLD) that comprises an access point (AP) MLD or a non-AP MLD.

5. The apparatus of claim 1, wherein the at least one parameter comprises a link capacity of at least one of the first wireless link or the second wireless link.

6. The apparatus of claim 1, wherein: the first AMPDU size is proportional to a bandwidth of the first wireless link; and the second AMPDU size is proportional to a bandwidth of the second wireless link.

7. The apparatus of claim 1, wherein: the first AMPDU size is based on a first value proportional to a bandwidth of the first wireless link or a minimum AMPDU size; and the second AMPDU size is based on a second value proportional to a bandwidth of the second wireless link or the minimum AMPDU size.

8. The apparatus of claim 7, wherein each of the first and second values is based on a factor that controls how fast a block acknowledgment (BA) window can be depleted.

9. The apparatus of claim 1 , wherein the at least one parameter is based on a measure of capacity of at least one of the first wireless link or the second wireless link.

10. The apparatus of claim 1, wherein the at least one parameter depends on at least one of a quantity of streams, a modulation and coding scheme (MCS) or a bandwidth of at least one of the first wireless link or the second wireless link.

11. The apparatus of claim 1, wherein the allocation is also based on a block acknowledgment (BA) size.

12. The apparatus of claim 1, wherein the one or more processors are further configured to execute the computer-executable instructions and cause the apparatus to allocate, based on the at least one parameter, a first aggregated medium access control (MAC) service data unit (AMSDU) size to the first wireless link and a second AMSDU size to the second wireless link.

13. The apparatus of claim 12, wherein the first AMSDU size and the second AMSDU size are the same.

14. The apparatus of claim 1, wherein the allocation is also based on a priority of at least one of the first wireless link or the second wireless link.

15. The apparatus of claim 1, wherein the allocation is configured to ensure at least a minimum quantity of consecutive physical layer protocol data units to be transmitted in a transmission duration via at least one of the first wireless link or the second wireless link.

16. The apparatus of claim 15, wherein at least one of the first AMPDU size or the second AMPDU size is allocated based on a modulation and coding scheme (MCS).

17. The apparatus of claim 1, wherein each of the first AMPDU size and the second AMPDU size is based on a remaining block acknowledgment (BA) window size, wherein the remaining BA window size is a function of a location of a first failed MPDU sequence number, a BA size, and a last transmitted MPDU sequence number.

18. A wireless node, comprising: at least one transceiver; a memory comprising computer-executable instructions; and one or more processors configured to execute the computer-executable instructions and cause the apparatus to: establish at least a first wireless link and a second wireless link with another wireless node; allocate, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link; and communicate, via the at least one transceiver, with the other wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

19. The wireless node of claim 18, wherein the first and second wireless links share a common sliding window of sequence numbers.

20. A method for wireless communication at a first wireless node, comprising: establishing at least a first wireless link and a second wireless link with a second wireless node; allocating, based on at least one parameter that is asymmetric on the first wireless link and on the second wireless link, a first aggregated medium access control (MAC) protocol data unit (AMPDU) size to the first wireless link and a second AMPDU size to the second wireless link; and communicating with the second wireless node with AMPDUs via the first and second wireless links, in accordance with the allocation.

Images