Apparatus and method for data transmission

Abstract

Compared to traditional wireless communication techniques, multi-link operation can provide higher network throughput and higher network flexibility. Embodiments of the present invention provide techniques for simultaneously transmitting frames of aggregate MAC protocol service units (A-MSDU) on multiple links in multi-link operation between wireless devices (e.g., wireless stations and wireless access points). The A-MSDU can be aggregated to meet the capability requirements of the transmitting device and / or the receiving device. In addition, the A-MSDU can be segmented, for example, to meet the maximum mac protocol data unit (MPDU) length requirements of the transmitting device and / or the receiving device. Some embodiments disclosed herein use a virtual Media Access Control (MAC) address of a Logical Link Control (LLC) sublayer interface to define parameter values of A-MSDU subframe headers (e.g., source and destination addresses) for routing the corresponding frames to the LLC sublayer interface of the receiving device.

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention relate generally to the field of wireless communications. More particularly, embodiments of the present invention relate to systems and methods for transmitting frames simultaneously over multiple links in a wireless network. BACKGROUND

[0002] Modern electronic devices often use Wi-Fi to wirelessly transmit and receive data with other electronic devices, and many of these devices are “dual-band” devices that include at least two wireless transceivers capable of operating at different frequency bands, such as 2.4 GHz, 5 GHz, and 6 GHz. In most cases, a wireless device can only communicate on a single frequency band at a time. For example, older and lower power devices, such as battery-powered devices, often operate at the 2.4 GHz frequency band. Newer devices and devices that require more bandwidth often operate at the 5 GHz frequency band. The availability of the 6 GHz frequency band is a recent development that can provide higher performance, lower latency, and faster data rates.

[0003] In some cases, the use of a single frequency band can not meet the bandwidth needs of a particular device. Accordingly, some developing methods for wireless communication increase the communication bandwidth by operating on multiple frequency bands simultaneously (technically referred to as link aggregation or multi-link operation). Multi-link operation can provide higher network throughput and higher network flexibility compared to traditional wireless communication techniques.

[0004] Under existing standards, frame aggregation can be used to collect frames to be transmitted to one or more targets and encapsulate them in a single 802.11n frame for efficiency. An aggregated media access control service data unit (A-MSDU) contains subframe headers with destination address (DA) and source address (SA) parameter values that map to the same receiver address (RA) and transmitter address (TA) values. However, because MAC service data unit (MSDU) aggregation is performed before MAC protocol data unit (MPDU) generation, it is currently difficult to define the destination address (DA) and source address (SA) in A-MSDU subframe headers for fragmented frames using multi-link operation.

[0005] In addition, wireless APs need a method to determine the capabilities of associated devices, e.g., to determine whether a receiving wireless station (STA) supports multi-link segmentation and to determine the A-MSDU capability requirements of the receiving STA. Each MAC entity of a receiving STA can have different A-MSDU capabilities and configurations, e.g., different number of A-MSDUs that can be carried in an A-MSDU, different maximum MPDU length that the STA can receive, and different maximum A-MSDU length that the STA can receive. Transmitting data to different MAC entities with different A-MSDU capabilities can result in poor performance when the different A-MSDU capabilities are not considered by the transmitting device. SUMMARY

[0006] Accordingly, embodiments of the present application provide techniques for transmitting A-MSDUs on multiple links simultaneously in multi-link operations between wireless devices, e.g., wireless STAs and wireless access points (APs). The A-MSDUs can be aggregated to meet the capability requirements of the transmitting device and / or the receiving device. In addition, the A-MSDUs can be segmented, e.g., to meet the MPDU length requirements of the transmitting device and / or the receiving device. Some embodiments disclosed herein use a virtual media access control (MAC) address of a logical link control (LLC) sublayer interface to define the parameter values of the A-MSDU subframe header (e.g., SA and DA) to route the corresponding frames to the LLC sublayer interface of the receiving device.

[0007] According to an embodiment, a method of transmitting data by a transmitting device in multi-link operations on a wireless network is disclosed. The method includes determining that a receiving device is capable of multi-link segmentation, the receiving device and the transmitting device operable to communicate over a first wireless link and a second wireless link, determining a first media access control (MAC) protocol data unit (PDU) length capability of the first wireless link of the receiving device and a second MPDU length capability of the second wireless link of the receiving device, and transmitting a first frame on the first wireless link and a second frame on the second wireless link to the receiving device in the multi-link operations.

[0008] According to some embodiments, the method includes determining that a length of the A-MSDU is greater than the first MPDU length capability; and segmenting an aggregate MAC protocol service unit (A-MSDU) into a first segment frame and a second segment frame according to the MPDU length capability, wherein the A-MSDU is segmented using a segment that is less than the first wireless link MPDU length capability, the first frame includes the first segment frame, and the second frame includes the second segment frame.

[0009] According to some embodiments, the length of the A-MSDU is greater than at least one of the first MPDU length capability and the second MPDU length capability, a length of the first segment frame is not greater than the first MPDU length capability, and a length of the second segment frame is not greater than the second MPDU length capability.

[0010] According to some embodiments, the first frame is transmitted on the first wireless link concurrently with the second frame being transmitted on the second wireless link.

[0011] According to some embodiments, the first frame and the second frame are associated with a same traffic identifier (TID) allocated to the first wireless link and the second wireless link.

[0012] According to some embodiments, the method includes receiving, from the receiving device, an extended capabilities element including A-MSDU capability requirements; and aggregating the A-MSDU to satisfy the A-MSDU capability requirements of the extended capabilities element.

[0013] According to some embodiments, the receiving device is further operable to communicate on a third wireless link, and aggregating the A-MSDU to satisfy the A-MSDU capability of the extended capabilities element includes identifying a set of eligible links that satisfy the A-MSDU capability of the extended capabilities element, the set of eligible links including at least one of: the first wireless link; the second wireless link; and the third wireless link.

[0014] According to some embodiments, the first wireless link includes a 2.4 GHz wireless link, the second wireless link includes a 5 GHz wireless link, and the third wireless link includes a 6 GHz wireless link.

[0015] According to different embodiments, a method of transmitting data by a transmitting device to a receiving device in multi-link operation on a wireless network is disclosed. The method includes receiving a transmission opportunity (TXOP) on a first wireless link at a first wireless station (STA) instance of a plurality of wireless STA instances of the transmitting device, setting a SA field of an A-MSDU subframe header of an aggregate media access control protocol service unit (A-MSDU) according to a virtual MAC address of a logic link control (LLC) sublayer interface of the transmitting device, setting a DA field of the A-MSDU subframe header of the A-MSDU according to a virtual MAC address of an LLC sublayer interface of the receiving device for delivery of the A-MSDU to the LLC sublayer of the receiving device, and transmitting the A-MSDU to the receiving device on the first wireless link.

[0016] According to some embodiments, the method includes setting a TA field of a MAC header of the A-MSDU according to a MAC address of the first wireless STA instance, and setting a RA field of the MAC header of the A-MSDU according to a MAC address of a wireless AP instance of the receiving device.

[0017] According to some embodiments, the method includes receiving a transmission opportunity (TXOP) on a second wireless link at a second wireless STA instance of the plurality of wireless STA instances of the transmitting device, setting a SA field of a second A-MSDU subframe header of a second A-MSDU according to the virtual MAC address of the LLC sublayer interface of the transmitting device, setting a DA field of the second A-MSDU subframe header of the second A-MSDU according to the virtual MAC address of the LLC sublayer interface of the receiving device for delivery of the second A-MSDU to the LLC sublayer of the receiving device, and transmitting the second A-MSDU to the receiving device on the second wireless link.

[0018] According to some embodiments, the first A-MSDU is transmitted simultaneously with the second A-MSDU.

[0019] According to some embodiments, the virtual MAC address of the LLC sublayer interface of the transmitting device corresponds to a MAC address of a wireless STA instance of the plurality of wireless STA instances.

[0020] According to some embodiments, the virtual MAC address of the LLC sublayer of the receiving device corresponds to a MAC address of a wireless AP instance of the receiving device.

[0021] According to another embodiment, an apparatus for transmitting data to a receiving device in multi-link operation on a wireless network is disclosed. The apparatus comprises a multi-band wireless station (STA) comprising a plurality of wireless STA instances, each of the plurality of wireless STA instances being associated with a respective media access control (MAC) address, and a logic link control (LLC) sublayer interface associated with a first MAC address of a first wireless STA instance of the plurality of wireless STA instances. The multi-band wireless STA is operable to receive, at a second wireless STA instance of the plurality of wireless STA instances of the transmitting device, a transmission opportunity (TXOP) for transmission of an aggregated MAC protocol data unit (A-MSDU), set a SA field of an A-MSDU subframe header of the A-MSDU according to a virtual MAC address of the LLC sublayer interface of the transmitting device, set a DA field of the A-MSDU subframe header of the A-MSDU according to a virtual MAC address of the LLC sublayer interface of the receiving device to transmit the A-MSDU to the LLC sublayer of the receiving device, and transmit the A-MSDU to the receiving device using the virtual MAC address in the A-MSDU subframe header.

[0022] According to some embodiments, the multi-band wireless STA is further operable to aggregate the A-MSDU for transmission using the A-MSDU subframe header.

[0023] According to some embodiments, the multi-band wireless STA is further operable to aggregate the A-MSDU according to A-MSDU capability requirements of the receiving device.

[0024] According to some embodiments, the A-MSDU capability requirements of the receiving device comprise a maximum MAC protocol data unit (MPDU) length, and the STA is further operable to aggregate the A-MSDU using a length satisfying the A-MSDU capability requirements.

[0025] According to some embodiments, the plurality of wireless STA instances communicate with the receiving device on a plurality of wireless links, and the multi-band wireless STA is further operable to aggregate the A-MSDU according to A-MSDU capability requirements of the receiving device by determining that a set of eligible links of the plurality of wireless links satisfy the A-MSDU capability requirements of the receiving device.

[0026] According to some embodiments, the A-MSDU and the second A-MSDU comprise fragmented frames of the same initial A-MSDU. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application:

[0028] Figure 1 A block diagram illustrating an exemplary wireless communication system including a multi-band cooperating AP and a multi-band cooperating STA according to embodiments of the application.

[0029] Figure 2 A block diagram illustrating exemplary multi-link operations performed by a wireless STA according to embodiments of the application.

[0030] Figure 3 A block diagram illustrating exemplary multi-link operations using traffic identification performed by a wireless STA according to embodiments of the application.

[0031] Figure 4 A block diagram illustrating exemplary multi-link operations using multiple fragmented frames according to embodiments of the application.

[0032] Figure 5 A block diagram illustrating an exemplary wireless computer system using a virtual MAC address for performing multi-link operations for setting RA or TA parameter values in MAC headers of corresponding A-MSDU according to embodiments of the application.

[0033] Figure 6 A block diagram illustrating an exemplary A-MSDU frame format according to embodiments of the application.

[0034] Figure 7 A flow diagram illustrating an exemplary computer-implemented process for transmitting data in multi-link operations using A-MSDU according to embodiments of the application.

[0035] Figure 8A A flow diagram illustrating an exemplary computer-implemented process for uplink data transmission by a transmitting device using a virtual MAC address assigned to an LLC sublayer interface according to embodiments of the application.

[0036] Figure 8B A flow diagram illustrating an exemplary computer-implemented process for downlink data transmission by a receiving device using a virtual MAC address assigned to an LLC sublayer interface according to embodiments of the application.

[0037] Figure 9 A block diagram depicting an exemplary computer system platform upon which embodiments of the application can be implemented. DETAILED DESCRIPTION

[0038] Several embodiments will be described in detail below. Although the subject matter will be described in the context of alternative embodiments, it should be appreciated that they are not the only embodiments possible, and are not intended to limit the scope of the claimed subject matter to these embodiments. Rather, the claimed subject matter is intended to cover all alternatives, modifications and equivalents, which can be included within the spirit and scope of the claimed subject matter as defined by the appended claims.

[0039] Furthermore, in the following detailed description, numerous specific details are described to provide a thorough understanding of the claimed subject matter. However, it will be apparent to one of ordinary skill in the art that embodiments of the claimed subject matter can be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the subject matter.

[0040] Portions of the detailed description that follow are presented and discussed in terms of methods. Although steps and sequences are disclosed in flow charts (e.g., FIGS. 8A and 8B) that describe the operation of the methods, it is understood that these steps and sequences are exemplary. Embodiments are well suited to performing various other steps or variations of the steps recited in the flow charts of the figures herein, and in different orders than those depicted. Figure 7

[0041] Portions of the detailed description are presented and discussed in terms of processes, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A process, computer-executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0042] ​It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as "accessing," "configuring," "coordinating," "storing," "transmitting," "authenticating," "identifying," "requesting," "reporting," "determining," or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

[0043] New techniques for EHT multi-band A-MSDU operation

[0044] As used herein, the term "EHT" can generally refer to a new generation of wireless communication (Wireless Fidelity, or Wi-Fi) known as extreme high-throughput (EHT) and defined according to the IEEE 802.1 lbe standard. The term station (STA) generally refers to an electronic device capable of sending and receiving data over Wi-Fi, which does not operate as an access point (AP).

[0045] Compared to conventional wireless communication techniques, multi-link operation can provide higher network throughput and higher network flexibility. Embodiments of the present disclosure provide techniques for simultaneously transmitting frames of A-MSDUs over multiple links in multi-link operation between wireless devices (e.g., wireless STAs and wireless APs). The A-MSDUs can be aggregated to meet the capability requirements of the transmitting device and / or the receiving device. In addition, the A-MSDUs can be segmented, e.g., to meet the MPDU length requirements of the transmitting device and / or the receiving device. Some embodiments disclosed herein use the virtual MAC address of the LLC sublayer interface to define the parameter values of the A-MSDU subframe headers (e.g., SA and DA) used to route the corresponding frames to the LLC sublayer.

[0046] Regarding Figure 1An exemplary wireless communication system 100 including a multi-band coordinated AP 105 and a multi-band coordinated STA 155, in accordance with embodiments of the present application, is shown. The multi-band coordinated AP 105 includes a 5 GHz transceiver 110 and a 2.4 GHz transceiver 115. Other types of transceivers operating on different bands, such as 6 GHz and above, can also be used by the multi-band coordinated AP 105, in accordance with embodiments of the present application. The transceivers 110 and 115 of the AP 105 exchange data and information with a coordination management unit 120, which coordinates information transmitted and / or received by the transceivers 110 and 115.

[0047] The multi-band coordinated STA 155 includes a 5 GHz transceiver 160 and a 2.4 GHz transceiver 165. Other types of transceivers operating on different bands, such as 6 GHz and above, can also be used by the multi-band coordinated STA 155, in accordance with some embodiments of the present application. The transceivers 160 and 165 of the STA 155 exchange data and information with a coordination management unit 170 using 5 GHz band wireless communications and 2.4 GHz band wireless communications, respectively (although well-known wireless communications bands, such as 6 GHz, can also be used), which coordinates information transmitted and received by the transceivers 160 and 165.

[0048] The first band coordinated AP 105 and the multi-band coordinated STA 155 have simultaneous transmit and receive capabilities for communicating using different wireless bands. Transmitters operating on different bands can perform independent clear channel assessments (CCAs) using joint or independent transmissions. In addition, full-duplex communications can be enabled through independent multi-band operation using FDD mode.

[0049] Simultaneous transmission of frames using multiple bands by the STA 155 can reduce latency and increase peak throughput of the STA 155. However, in some cases, simultaneous transmission of frames using multiple bands can degrade performance of a basic service set (BSS) that includes the STA 155. For example, when the STA 155 operating on multiple bands simultaneously uses a large amount of bandwidth available to the BSS due to increased traffic, performance of the BSS can be degraded. Accordingly, the AP 105 can control which STAs are granted multi-band channel access, and the access can be terminated by the AP at any time, e.g., based on changed network conditions or requirements.

[0050] Depending on certain conditions, such as traffic load, a non-AP STA can use less than all supported / available links to reduce energy consumption. In addition, a non-AP STA can apply independent power management for each link, and an AP can provide TID-to-link mapping information for each link. According to the Quality of Service (QoS) policy of a basic service set (BSS), an AP can allocate traffic to different links according to traffic type (e.g., voice, video, data, etc.). For example, frames belonging to a first traffic identification (TID 1) are allocated to a first link, and frames belonging to a second traffic identification (TID 2) are allocated to a second link. In this case, the AP can provide two pieces of TID-to-link mapping information to the wireless STA, where some data can only be sent on the first link, and other data can only be sent on the second link.

[0051] Data transmitted on a first wireless link, such as a 5 GHz wireless link provided by the 5 GHz transceiver 110 or 160, can be retransmitted on a different wireless link. For example, if a data transmission is not successfully transmitted (e.g., an acknowledgement is not received) on the 5 GHz wireless link, the data can be retransmitted on a 2.4 GHz wireless link provided by the 2.4 GHz transceiver 115 / 165. A data transmission (e.g., a PPDU) is initially encoded for transmission on a first wireless link (e.g., a 2.4 GHz or 5 GHz wireless link), and according to embodiments of the application described herein, the retransmitted data is prepared for transmission to encrypt the data for retransmission in a multi-link environment.

[0052] Figure 2 is a block diagram of an exemplary multi-link operation performed by a wireless STA according to embodiments of the application. The wireless STA obtains a transmission opportunity (TXOP) in multiple frequency bands, including a 2.4 GHz wireless frequency band 205 and a 5 GHz wireless frequency band 210. When the wireless STA obtains the TXOP in the multiple frequency bands, the STA can simultaneously transmit frames in the multiple frequency bands. As shown, the wireless STA simultaneously transmits PPDU1 (215) on the 2.4 GHz wireless frequency band 205 and PPDU2 (220) on the 5 GHz wireless frequency band 210. As described above, simultaneous transmission of data on multiple links according to embodiments of the application can reduce latency and increase the peak throughput of the wireless STA. Figure 2

[0053] Figure 3 ​This is a block diagram illustrating an exemplary multi-link operation using a Service Identifier (TID) performed by a wireless STA according to an embodiment of the present invention. When a transmitted frame is under a block acknowledgment protocol, an add block acknowledgment (ADDBA) request frame may include one or more multi-band information elements indicating the frequency band on which the wireless STA can transmit frames with the TID indicated in the ADDBA request frame. When the STA transmits frames in one or more frequency bands (“in-progress bands”) and transmits new frames in different frequency bands using frame scheduling under the block acknowledgment protocol, if a reordering buffer for the TID of the in-progress frame is available, the STA selects a scheduled frame from the TID that is the same as the TID of the in-progress frame. Otherwise, the STA selects a scheduled frame from the TID that is different from the TID of the in-progress frame.

[0054] like Figure 3 As shown, the STA simultaneously transmits data frame 305 on the 2.4 GHz radio band 310 and data frame 315 on the 5 GHz radio band 320. The data frame corresponds to sequence Seq1, and data frame 315 corresponds to sequence Seq2 associated with TID1. The in-process frame 305 is not under the block acknowledgment protocol (there is no block acknowledgment protocol on TID1). In this case, if data frame 305 of sequence Seq1 fails, the STA can retransmit data frame 305 in data frame 325. It could be problematic if the receiving radio device transmits data frame 310 of sequence Seq2 to the upper layer before transmitting the retransmitted data frame 325 of Seq1 to the upper layer. To avoid disordered transmission of frames to the upper layer (e.g., Seq2 before Seq1), when a frame is not transmitted under the block acknowledgment protocol, the STA schedules the frame from a TID different from the TID of the in-process frame. However, this approach may limit the benefits gained through multi-link operation.

[0055] Optionally, to maintain the performance of multi-link operation, according to some embodiments, the STA schedules a frame with the same TID as the ongoing frame only if there are no remaining retries for the ongoing frame, and the time of the scheduled frame is no earlier than the end time of the ongoing frame's transmission. Otherwise, the STA schedules a frame with a TID different from the ongoing frame's TID.

[0056] To schedule the transmission of aggregate MSDUs (A-MSDUs), the transmitting STA must define the destination address (DA) and source address (SA) for the MSDUs being transmitted in the multi-link operation in the A-MSDU subframe header. However, since MSDU aggregation is performed prior to the generation of MPDUs, the DA and SA in the A-MSDU subframe header corresponding to the respective MPDUs are independently determined on the link that obtained the TXOP in the multi-link operation. In the current MAC data plane architecture, A-MSDU aggregation is the first procedure performed on the TX side, while de-aggregation is one of the last procedures performed on the RX side. Thus, when A-MSDUs are carried in QoS data frames with the regular Ack policy, a wireless STA can receive A-MSDUs sent by a high throughput (HT) STA when the A-MSDUs are not aggregated within an A-MPDU (aggregate MPDU), or a wireless STA can receive A-MSDUs sent by a VHT STA when the A-MSDUs are sent as a single MPDU (S-MPDU).

[0057] For each block acknowledgement protocol, a STA can send A-MSDUs within QoS data frames under the block acknowledgement protocol unless the receiver indicates support for A-MSDUs by setting the A-MSDU supported field of the BlockAck Parameters Set field of the ADDBA Response frame to "1". As described above, the ADDBA Request frame can include more than one multi-band information element indicating the frequency bands on which the wireless STA can send frames for the TIDs indicated in the ADDBA Request frame. Importantly, a wireless STA will not send A-MSDUs to a receiving wireless STA if the A-MSDU length exceeds the value indicated by the Maximum A-MSDU Length field of the HT Capabilities element received from the receiving STA.

[0058] The length of an A-MSDU sent in a VHT PPDU is limited by the maximum MPDU size supported by the receiving STA. In addition, a VHT STA cannot send an A-MSDU that includes a number of MSDUs that is greater than the value indicated by the Maximum Number of MSDUs in A-MSDU field in any Extended Capabilities element sent by the receiving STA, and an HT STA cannot send an A-MSDU that includes a number of MSDUs that is greater than the value indicated by the Maximum Number of MSDUs in A-MSDU field in any Extended Capabilities element sent by the receiving STA.

[0059] Figure 4A block diagram illustrating an exemplary multi-link operation using multiple fragmented frames according to embodiments of the application. When a multi-band STA supports dynamic fragmentation, it can perform fragmentation of an A-MSDU whose length does not satisfy the maximum MPDU length capability of the link. Fragmentation is typically performed after A-MSDU aggregation. When a frame is fragmented, all fragments carrying the fragmented frame are transmitted by the same link unless the receiving STA supports multi-link fragmentation. When the receiving STA indicates support for multi-link fragmentation, the transmitting multi-band STA can transmit the fragmented frame on multiple links simultaneously when the maximum MPDU length capability of the link is greater than or equal to the size of the fragmented frame.

[0060] When the ongoing frame is a fragmented frame, the STA can select one of the remaining fragmented frames to schedule transmission. As shown, the STA transmits an ongoing data frame 405 including fragment FragO of sequence Seqi (associated with TIDi) on the 2.4 GHz wireless link 410, and schedules a data frame 415 including fragment Fragl of sequence Seqi (also associated with TIDi) for transmission on the 5 GHz wireless link 420 when the maximum MPDU length capability of the 5 GHz link is greater than or equal to the size of the fragmented frame 415. Figure 4

[0061] According to some embodiments, the fragmentation parameters (e.g., frame size) cannot be changed. If the length of the MPDU carrying the remaining fragmented frame is greater than the maximum MPDU length (Maximum MPDU Length capability) capability of another link, the remaining fragmented frame cannot be transmitted on that link. Also, when the initial transmission of a frame is not fragmented, any retransmission of that frame is not fragmented. Thus, if the MPDU length of the initial transmission is greater than the maximum MPDU length capability of another link, the frame cannot be retransmitted on that link.

[0062] Figure 5 ​is a block diagram of an exemplary wireless computer system 500 according to embodiments of the present application for performing multi-link operations using virtual MAC addresses to set RA or TA parameter values in MAC headers of corresponding A-MSDUs. Multi-band wireless AP 505 includes multiple AP instances API 510, AP2 515, and AP3 520 capable of performing multi-band operations including simultaneously transmitting or receiving frames on multiple frequency bands. Multi-band wireless STA 525 includes multiple STA instances STA1 530, STA2 535, and STA3 540 capable of performing multi-band operations including simultaneously transmitting or receiving frames on multiple frequency bands. API 510 and STA1 530 communicate on a 2.4 GHz wireless link (link 1), AP2 515 and STA2 535 communicate on a 5 GHz wireless link (link 2), and AP3 520 and STA1 540 communicate on a 6 GHz wireless link (link 3).

[0063] Logical link control (LLC) sub-layers 550 and 555 are coupled to multi-band AP 505 and multi-band STA 510, respectively. LLC sub-layer 550 is assigned a virtual MAC address V_MAC_ADDRAP, and LLC sub-layer 555 is assigned a virtual MAC address V_MAC_ADDRSTA. LLC sub-layers 550 and 555 communicate with multiple AP and STA instances (e.g., MAC / PHY entities) using interfaces associated with the corresponding virtual MAC addresses. Multi-band wireless AP 505 includes MAC / PHY entities of wireless AP instances 510, 515, and 520 configured to operate on different frequency bands, and multi-band wireless STA 525 includes MAC / PHY entities of wireless STA instances 530, 535, and 540 configured to operate on different frequency bands. As shown, the values of the virtual MAC addresses are assigned as MAC addresses corresponding to one of the MAC / PHY entities, such as MAC_ADDR4 (AP side) associated with API 510 and MAC_ADDR1 (STA side) associated with STA 530. Figure 5

[0064] ​When the wireless multi-band STA 510 transmits MPDUs on multiple links, the receiver address (RA) and transmitter address (TA) values of the MAC header of the corresponding A-MSDU are obtained by the STA after it obtains the TXOP. In this example, the MAC address associated with the MAC / PHY entity of the link on which the wireless multi-band STA 510 obtains the TXOP is used to set the RA and TA parameter values of the MAC header of the frame to be transmitted on link 3. To transmit the frame on link 3 to the multi-band AP 505 and route link 3 to the interface of the LLC sublayer 550, the multi-band STA 510 sets the RA field in the MAC header of the A-MSDU to MAC_ADDR6 and the TA field in the MAC header of the A-MSDU to MAC_ADDR3.

[0065] Under the existing frame aggregation method, the DA and SA parameter values in the subframe header of the A-MSDU subframe are set to the same RA and TA parameter values in the MAC header of the A-MSDU. However, because MSDU aggregation is performed prior to MPDU generation, the DA and SA in the A-MSDU subframe header should be determined independently for the particular link on which the TXOP is obtained in multi-link operation. Therefore, in Figure 5 In the example of FIG. 6, the SA parameter value of the A-MSDU subframe header is set to a virtual MAC address V_MAC_ADDRSTA (corresponding to MAC_ADDR1) and the DA parameter value of the A-MSDU subframe header is set to a virtual mac address V_MAC_ADDRAP (corresponding to MAC_ADDR4). It should be understood that the virtual MAC addresses are set to any of the MAC addresses of the MAC / PHY entity. In this way, using the virtual MAC addresses, the received frame is passed to the LLC sublayer interface and the LLC sublayer can pass the received data to higher sublayers (e.g., network layer).

[0066] According to some embodiments, each MAC entity of the receiving STA can have different A-MSDU capabilities and configurations. For example, each MAC entity can support a different number of MSDUs that can be carried in an A-MSDU, a different maximum MPDU length that the STA is capable of receiving, and a different maximum A-MSDU length that the STA is capable of receiving. Therefore, according to some embodiments, MSDU aggregation is performed to meet the A-MSDU capability requirements of all MAC entities of the receiving device. For example, when the receiving STA can receive n and m MSDUs in an A-MSDU transmitted from a first link and a second link, respectively, the transmitting multi-band STA cannot aggregate more than min(n, m) MSDUs in the A-MSDU to simultaneously meet the capability requirements of the first link and the second link.

[0067] In some cases, satisfying the A-MSDU capability requirements of all MAC entities of the receiving wireless STA can result in performance degradation. According to some embodiments, in order to maintain the performance level of multi-link operation, only the A-MSDU capability requirements (e.g., maximum number of MSDUs in A-MSDU, maximum MPDU length, and maximum A-MSDU length) of the following conditions are satisfied for a particular link or a set of links when aggregating A-MSDUs. The particular link that satisfies the selected capability requirements can be referred to as a “qualified link set.” When a multi-band STA schedules MPDUs after obtaining a TXOP, the MPDU containing A-MSDU is restricted to use the qualified link set to transmit the A-MSDU. For example, the transmitting multi-band STA can aggregate MSDUs while satisfying the A-MSDU capability requirements on the first link (link 1) only. In this case, the transmitting multi-band STA can schedule the MPDU containing the corresponding A-MSDU on the first link (link 1) only. In another example, the transmitting multi-band STA aggregates MSDUs while satisfying the A-MSDU capability requirements on the first link and the second link (link 2) simultaneously. In this case, the transmitting multi-band STA can schedule the MPDU containing the corresponding A-MSDU on the first link and the second link (link 1 + link 2) included in the qualified link set.

[0068] According to some embodiments, MSDUs belonging to a particular TID are assigned to a particular link or a set of links. In this case, when MSDUs belonging to the TID are aggregated for transmission, the multi-band STA satisfies a set of A-MSDU capability requirements (e.g., maximum number of MSDUs in A-MSDU, maximum MPDU length, and maximum A-MSDU length) for at least one of the particular links. The receiving STA can also declare separate multi-band specific A-MSDU capability requirements or a set of requirements. The receiving STA can announce its A-MSDU capability requirements in the multi-link setup frame in the multi-link setup negotiation phase, and the transmitting multi-band STA can aggregate MSDUs of the TID to satisfy the set of multi-band specific A-MSDU capability requirements indicated in the multi-link setup frame.

[0069] Figure 6 A block diagram illustrating an exemplary A-MSDU frame format 600 according to embodiments of the present application is shown. In Figure 6In some embodiments, an exemplary A-MSDU subframe 1-n is shown. Exemplary A- MPDU subframe n (630) includes MSDU field 625 and A-MSDU subframe header 605, which includes DA field 610, SA field 615 for setting the destination address and source address of the A-MSDU transmission, respectively, and length field 620 indicating the length of MSDU field 625 in bits. MSDU frame format 600 includes 3 bytes for padding 635. Exemplary MSDU frame format 600 can be used to implement embodiments of the application, e.g., to perform EHT multi-band A-MSDU operations, e.g., to transmit A-MSDU and / or fragmented frames simultaneously over multiple frequency bands. For example, the A-MSDU frame can be carried in a PSDU.

[0070] Figure 7 A flowchart of an exemplary computer-implemented process 700 for transmitting data in multi-link operations using A-MSDU / MSDU according to embodiments of the application is shown.

[0071] At step 705, a capability of the receiving device is determined. Step 705 can include receiving an indication of the capability from the receiving device. The capability can include, for example, support for multi-link fragmentation. The capability can also include MPDU capability requirements, e.g., MPDU length capability, maximum MSDU number in A-MSDU, etc.

[0072] At step 710, a MPDU length capability of a first wireless link and a MPDU length capability of a second wireless link are determined. The MPDU length capability can be associated with the transmitting device or the receiving device. For example, the determination step can be made according to a capability indication sent by the receiving device.

[0073] At step 715, the A-MSDU / MSDU is fragmented into a first fragmented frame and a second fragmented frame according to the MPDU length capability.

[0074] At step 720, the first fragmented frame and the second fragmented frame of the A-MSDU / MSDU are simultaneously transmitted to the receiving device in multi-link operations on the wireless network.

[0075] Figure 8A A flowchart of an exemplary computer-implemented process 800 is shown, which is used by a transmitting device for uplink transmission of data using a virtual MAC address assigned to a LLC sublayer interface according to embodiments of the application. The wireless STA can be a MLD non-AP STA and the wireless AP can be a MLD AP.

[0076] At step 805, a TXOP is received on a first wireless link at a first wireless STA instance of the transmitting device.

[0077] At step 810, the SA field of one or more A-MSDU subframe headers of the A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the transmitting device.

[0078] At step 815, the DA field of one or more A-MSDU subframe headers of the A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the receiving device for transmitting the A-MSDU to the LLC sublayer of the receiving device.

[0079] At step 820, the TA field of the MAC header of the A-MSDU is set according to the MAC address of the first wireless STA instance.

[0080] At step 825, the RA field of the MAC header of the A-MSDU is set according to the MAC address of the wireless AP instance of the receiving device.

[0081] For transmitting a second A-MSDU on a second wireless link, steps 805-825 can be repeated for simultaneously transmitting multiple frames to the receiving device in a multi-link operation. For example, another TXOP is received on a second wireless link of a second wireless STA instance of the transmitting device. The SA field of the A-MSDU subframe header of the second A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the transmitting device, and the DA field of the A-MSDU subframe header of the second A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the receiving device for transmitting the A-MSDU to the LLC sublayer of the receiving device. The TA field of the MAC header of the second A-MSDU is set according to the MAC address of the second wireless STA instance of the transmitting device, and the RA field of the MAC header of the second A-MSDU is set according to the address of the second wireless AP instance of the receiving device.

[0082] At step 830, the A-MSDU is transmitted by the transmitting device to the receiving device on the first wireless link using the virtual MAC address in the A-MPDU subframe header. According to another embodiment, step 830 can further include transmitting a second A-MSDU to the receiving device on a second wireless link using the virtual MAC address while transmitting the A-MSDU on the first wireless link in a multi-link operation.

[0083] Figure 8B A flowchart illustrating an exemplary computer-implemented process 850 is shown, according to an embodiment of the application, for downlink transmission of data by a transmitting device using a virtual MAC address assigned to a LLC sublayer interface. The wireless STA can be a MLD non-AP STA, and the wireless AP can be a MLD AP.

[0084] At step 855, the SA field of one or more A-MSDU subframe headers of the A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the MLD AP.

[0085] At step 860, the DA field of one or more A-MSDU subframe headers of the A-MSDU is set according to the virtual MAC address of the LLC sublayer interface of the MLD non-AP STA, so that the LLC sublayer of the receiving device receives the A-MSDU.

[0086] At step 865, the TA field of the MAC header of the A-MSDU is set according to the MAC address of the first wireless AP instance of the wireless MLD AP.

[0087] At step 870, the RA field of the MAC header of the A-MSDU is set according to the MAC address of the wireless STA instance of the MLD non-AP STA.

[0088] Steps 855-870 can be repeated to transmit a second A-MSDU on a second wireless link, to simultaneously transmit multiple frames to a receiving device in a multi-link operation as described above.

[0089] At step 875, the A-MSDU is transmitted by the MLD AP to the MLD non-AP STA on the first wireless link using the virtual MAC address in the A-MPDU subframe header. According to another embodiment, step 875 can also include transmitting a second A-MSDU to the receiving device on a second wireless link using the virtual MAC address simultaneously with the transmission of the A-MSDU on the first wireless link in a multi-link operation.

[0090] Example computer control system

[0091] Embodiments of the present invention relate to electronic systems that perform multi-link operations in wireless networks. Multi-link operations can include aggregating MPDUs and simultaneously transmitting or receiving A-MSDUs on multiple wireless links, such as Figure 6 An example A-MSDU subframe is depicted in FIG. 9. Aggregation can include setting parameter values of the A-MSDU subframe header to correspond to a virtual MAC address of the LLC sublayer, and can be performed according to capability requirements of the transmitting device and / or the receiving device. The following discussion describes one such example electronic system or computer system that can be used as a platform to implement embodiments of the present invention. For example, the example computer system 912 can be a wireless access point or a wireless station.

[0092] In Figure 9In the example of FIG. 9, an example computer system or wireless device includes a central processing unit (CPU) 901, such as a processor or CPU, for running software applications as well as optionally an operating system. Read only memory 902 and random access memory 903 store applications and data for use by the CPU 901. A data storage device 904 provides non-volatile storage for applications and data and can include fixed or removable magnetic or optical disk drives, flash memory devices, and Compact Disc Read-only Memory (CD-ROM), Digital Versatile Disc-Read only Memory (DVD-ROM), or other optical storage devices. Optional user input devices 906 and 907 include devices such as a mouse, joystick, camera, touchpad, and / or microphone that enable a user to communicate with the computer system 912.

[0093] The communication or network interface 908 includes multiple transceivers and allows the computer system 912 to communicate with other computer systems, networks, or devices via electronic communication networks, including wired and / or wireless communication networks and including an Intranet or the Internet (e.g., 802.11 wireless standards). According to embodiments of the present application, the communication or network interface 908 can operate multiple transceivers simultaneously. The communication or network interface 908 can include a dual-band interface that can operate in multiple frequency bands simultaneously, such as 2.4 GHz, 5 GHz, and / or 6 GHz.

[0094] The optional display device 909 can be any device capable of displaying visual information in response to a signal from the computer system 912 and can include, for example, a flat panel touch-sensitive display, and can be remotely located. The components of the computer system 912, including the CPU 901, the memory 902 / 903, the data storage device 904, the user input devices 906, and the graphics subsystem 905, can be coupled via one or more data buses.

[0095] Some embodiments can be described in the general context of computer- executable instructions, such as programs modules, being executed by one or more computers or other devices. Generally, such programs modules include routines, programs, objects, components, data structures, and the like that perform particular tasks or implement particular abstract data types. Typically, the functionality of the programs modules can be combined or distributed as desired in various embodiments.

[0096] Accordingly, embodiments of the present application are described. While the present application has been described in terms of particular embodiments, it is not intended that it should be limited to such embodiments as the present application is intended to cover all alternatives, modifications and equivalents falling within the scope of the claims appended hereto.

Claims

1. A method of transmitting data for transmitting data by a transmitting device in multi-link operation of a wireless network, the method comprising: The method comprises: determining that a receiving device is capable of multi-link segmentation, wherein the receiving device and the transmitting device are operable to communicate on a first wireless link and a second wireless link; determining a first medium access control protocol data unit length capability of the receiving device for the first wireless link and a second medium access control protocol data unit length capability of the receiving device for the second wireless link; segmenting an aggregated medium access control protocol service unit into a first frame and a second frame according to the first medium access control protocol data unit length capability and the second medium access control protocol data unit length capability, respectively, wherein the first frame comprises a first segment frame and the second frame comprises a second segment frame; generating a virtual medium access control address for transmitting the first segment frame and the second segment frame for reception by a logical link control sublayer of the receiving device; and transmitting the first frame over the first wireless link and the second frame over the second wireless link to the receiving device in the multi-link operation using the virtual medium access control address, wherein the first frame comprises a first traffic identification, and wherein transmitting the first frame over the first wireless link is performed simultaneously with transmitting the second frame over the second wireless link; and scheduling a third frame for transmission over the first wireless link, wherein, if the first wireless link has no retransmission attempts, the third frame comprises the first traffic identification of the first frame; wherein, if the first wireless link has a number of retransmission attempts remaining, the third frame comprises a traffic identification different from the first traffic identification of the first wireless link.

2. The method of transmitting data according to claim 1, wherein, The method further comprises: determining that a length of the aggregated medium access control protocol service unit is greater than the first medium access control protocol data unit length capability.

3. The method of transmitting data according to claim 2, wherein, a length of the first segment frame is not greater than the first medium access control protocol data unit length capability, and wherein a length of the second segment frame is not greater than the second medium access control protocol data unit length capability.

4. The method of transmitting data of claim 1, wherein, the first frame and the second frame are associated with a same traffic identification assigned to the first wireless link and the second wireless link.

5. The method of transmitting data of claim 1, wherein, The medium access control protocol data unit comprises an aggregated medium access control protocol service unit, the method further comprising: receiving, from the receiving device, an extended capabilities element comprising an aggregated medium access control protocol service unit capability requirement; and aggregating a medium access control protocol service unit to satisfy the aggregated medium access control protocol service unit capability requirement of the extended capabilities element.

6. The method of transmitting data according to claim 5, wherein, The receiving device is further to communicate on a third wireless link, and wherein the aggregating the media access control protocol service units to meet the aggregating media access control protocol service unit capability requirement of the extended capability element comprises identifying a set of eligible links that meet the aggregating media access control protocol service unit capability requirement of the extended capability element, wherein the set of eligible links comprises at least one of: the first wireless link; the second wireless link; and the third wireless link.

7. The method of transmitting data according to claim 6, wherein, The first wireless link comprises a 2.4 GHz wireless link, the second wireless link comprises a 5 GHz wireless link, and the third wireless link comprises a 6 GHz wireless link.

Images