A method and system for multi-link transmission indication

Abstract

The application discloses a kind of multi-link transmission indication method and system, specifically for: multi-link sending device is sent BAR frame on specified link after completing A-MPDU data frame transmission on each link, BAR frame contains multi-link BAR type indication information and multi-link redundancy block confirmation information;Multi-link receiving device receives BAR frame, generates the BA frame indicating the receiving state of each MPDU on multiple links on specified link, BA frame contains multi-link BA type indication information, corresponding link indication information and MPDU receiving failure type information, according to the multi-link redundancy block confirmation information in BAR frame, simultaneously redundantly send BA frame on multiple links, can increase the probability of successful reception of BA frame.The application can improve the transmission efficiency of multi-link communication, increase the reliability of BA frame transmission, can distinguish different state information such as data frame decoding failure and data frame loss, lay the foundation for selecting appropriate acknowledgement retransmission link strategy.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication, and particularly relates to a multi-link transmission indication method and system. Background Technology

[0002] With the development of wireless technology, multi-link devices can support multi-link communication, such as communicating simultaneously in frequency bands like 2.4GHz, 5GHz, 6GHz, and even millimeter waves, or selecting the optimal frequency band among multiple links to ensure communication quality. In wireless LAN data transmission, after receiving an Aggregation Medium Access Control Protocol Data Unit (A-MPDU), the transmitting device can send a Block Acknowledgment Request (BAR) frame. The receiving device then responds with a corresponding Block Acknowledgment Frame (BA) based on the BAR type, providing feedback on the reception status of each MPDU in the received A-MPDU. In multi-link communication scenarios, multi-link devices support simultaneous communication on multiple links. A multi-link device can respond with a BA frame on only one link, carrying an indication of the A-MPDU reception status on multiple links to improve efficiency. Alternatively, it can redundantly respond with BA frames on multiple links simultaneously to improve the reliability of BA frame reception, requiring indication of redundancy and data packet reception status. Furthermore, it is necessary to indicate the specific type of data frame transmission failure (such as decoding failure, packet loss, etc.) to facilitate the selection and adoption of appropriate retransmission strategies. Traditional BA frames cannot indicate the link information to which the MPDU belongs, nor can they indicate the specific status information of the data frame transmission failure. Therefore, it is necessary to design a multi-link block acknowledgment request (BAR) frame and block acknowledgment (BA) frame structure that carries link information, data frame reception status, and data frame transmission failure type, suitable for multi-link MAC (Media Access Control) architectures. Summary of the Invention

[0003] To improve transmission reliability in multi-link communication scenarios, after the data transmitter sends multiple A-MPDUs corresponding to one or more Traffic Identifiers (TIDs) to the data receiver along multiple links, the data receiver can send a Multi-Link Block Acknowledgment (ML-BA) frame on a designated link to correctly feedback the reception status of each MPDU in the received A-MPDUs on multiple links. Alternatively, ML-BA frames can be redundantly sent simultaneously on multiple links. This invention provides a multi-link transmission indication method and system.

[0004] This invention provides a multi-link transmission indication method for uplink and downlink multi-link communication scenarios. When a multi-link data transmitter sends A-MPDUs from multiple links to the same data receiver, the data receiver carries block acknowledgment information of A-MPDUs from multiple links in a single multi-link BA frame. The method improves BA frame transmission reliability by sending multi-link BA frames on only one link to indicate whether each MDPU in each A-MPDU on multiple links has been correctly received, or by simultaneously and redundantly sending multiple link BA frames on multiple links. Furthermore, after the block acknowledgment field indicating whether each MDPU has been correctly received or failed, a variable-length indication MPDU reception failure type field is added to distinguish between data frame decoding failure and data frame loss status information.

[0005] When a multi-link data transmitter instructs a data receiver to simultaneously send a multi-link BA frame on one or more links, indicating whether each MDPU in the A-MPDU transmitted on multiple links has been correctly received, a multi-link BAR frame needs to be sent. The multi-link block acknowledgment frame redundancy transmission indication field is used to indicate whether the data receiver needs to repeatedly send the multi-link BA frame on multiple links.

[0006] The aforementioned BAR frame includes a multi-link block acknowledgment request indication field for indicating whether the acknowledgment information reply for each A-MPDU block on multiple links can be completed on a single link, and a multi-link block acknowledgment frame redundancy transmission indication field for indicating whether the receiving device should repeatedly transmit multi-link BA frames on multiple links.

[0007] When the multi-link transmission scenario uses a multi-MAC MLO architecture (i.e., each link has an independent MAC address), the multi-link BA frame carries multiple block acknowledgment information bitmaps corresponding to each link, as well as the link information of the corresponding link block acknowledgment bitmap, and adds a bitmap after the block acknowledgment bitmap to explain the reception failure type of each MPDU.

[0008] Multi-link devices sending multi-link BA frames include a multi-link block acknowledgment indication field, a corresponding link block acknowledgment bitmap link sequence number field, and an additional bitmap field in the block acknowledgment bitmap corresponding to the MPDU reception failure type. The multi-link block acknowledgment indication field indicates whether acknowledgment information for each A-MPDU block on multiple links has been completed on one link. The corresponding link block acknowledgment bitmap link sequence number field indicates the link information corresponding to the block acknowledgment bitmap. The bitmap field in the block acknowledgment bitmap corresponding to the MPDU reception failure type indicates whether the data frame reception error status is a decoding failure or the ability not to receive the data frame.

[0009] When the multi-link transmission scenario uses a single MAC MLO architecture (i.e., multiple links share a single MAC address), the multi-link BA frame carries a bitmap including multiple link block acknowledgment information. After the block acknowledgment bitmap, a bitmap is added to explain the reception failure type of each MPDU and the corresponding link information of the failed MPDU. The number of bits required for the link information is determined by the specific link information encoding granularity indication information.

[0010] The multi-link device sends a multi-link BA frame containing a multi-link block acknowledgment indication field, an additional bitmap link information encoding granularity field, and an additional bitmap field in the block acknowledgment bitmap indicating the MPDU reception failure type and the corresponding link sequence number of the MPDU reception failure. The multi-link block acknowledgment indication field indicates whether the acknowledgment information reply for each A-MPDU block on multiple links is completed on one link. The additional bitmap link information encoding granularity field indicates the number of bits required for encoding the corresponding MPDU link information in the additional bitmap. The additional bitmap field in the block acknowledgment bitmap indicating the MPDU reception failure type and the corresponding link sequence number of the MPDU reception failure indicates whether the data frame reception error is a decoding failure or the inability to receive the data frame, as well as the link information corresponding to the erroneous data frame.

[0011] This invention discloses a multi-link transmission indication system, comprising an access point and a station in a multi-link communication scenario. Both the station and the access point can operate on multiple links and serve as either a data transmitter or a data receiver. The data transmitter sends data to the data receiver on multiple links within a predetermined data transmission opportunity time. After data transmission is completed on multiple links, the data transmitter sends a multi-link type block acknowledgment request frame to the data receiver on a specific link. The data receiver sends a multi-link type block acknowledgment frame that simultaneously includes the data reception status of multiple links on only one specific link, or redundantly sends multi-link type block acknowledgment frames on multiple links simultaneously. In the multi-link type block acknowledgment frame, different link information indication methods are provided according to the multi-link device architecture, and information regarding the status type of data frame erroneous reception (decoding failure or failure to receive the data frame) is carried after the block acknowledgment information.

[0012] The beneficial technical effects of this invention are as follows:

[0013] This invention addresses multi-link communication scenarios, enabling multi-link transmitting devices to instruct receiving devices to reply with BA frames, providing link information. It allows for the transmission of BAR and BA frames on a single link, indicating the A-MPDU reception status across multiple links to improve efficiency. Alternatively, it allows for redundant transmission of the same BA frame across multiple links, increasing the reliability of BA frame transmission and avoiding unnecessary retransmissions due to BA frame reception failures. Furthermore, in addition to the existing BlockACK Bitmap field indicating correct or failed reception of each MDPU, a variable-length field indicating the MPDU reception failure type is added to differentiate between different statuses such as data frame decoding failure and data frame loss, laying the foundation for selecting an appropriate acknowledgment and retransmission link / strategy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a multi-link wireless communication system according to an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram illustrating the relationship between multiple link devices according to an embodiment of the present invention;

[0016] Figure 3 This is an interactive schematic diagram of the multi-link transmission indication method according to an embodiment of the present invention;

[0017] Figure 4 This is a schematic diagram of the structure of the multi-link block acknowledgment request frame according to an embodiment of the present invention;

[0018] Figure 5 This is a schematic diagram of redundant transmission of multi-link block acknowledgment frames according to an embodiment of the present invention;

[0019] Figure 6 This is a schematic diagram of a multi-link device architecture according to an embodiment of the present invention;

[0020] Figure 7 This is a schematic diagram of a multi-link block acknowledgment frame that can be used under a multi-MAC MLO architecture according to an embodiment of the present invention;

[0021] Figure 8 This is a schematic diagram illustrating the correspondence between the BA Bitmap and Multi-MAC BAAddBitmap bits in a multi-link BA frame according to an embodiment of the present invention;

[0022] Figure 9 This is a schematic diagram of the multi-link block acknowledgment frames that can be used under the second multi-MAC MLO architecture of the present invention;

[0023] Figure 10 This is a schematic diagram of the multi-link block acknowledgment frames that can be used under the third multi-MAC MLO architecture of the present invention;

[0024] Figure 11This is a schematic diagram of a multi-link block acknowledgment frame that can be used under a single MAC MLO architecture according to an embodiment of the present invention;

[0025] Figure 12 This is a schematic diagram illustrating the correspondence between the BA Bitmap and Single-MAC BA AddBitmap bits in a multi-link BA frame according to an embodiment of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] This invention discloses a multi-link transmission indication method and system. During the data transmission completion phase, a multi-link device acting as a data sender sends a Multi-Link Block Acknowledgment Request (ML-BAR) frame to a multi-link device acting as a data receiver. The ML-BAR frame utilizes the Reserved field in the BAR Control field to define both a Multi-Link BAR Indication subfield and a BA Repeat Indication subfield. The Multi-Link BAR Indication subfield indicates that the frame can be used as an ML-BAR frame to request the multi-link receiving device to send an ML-BA frame carrying multi-link block acknowledgment information, or as a regular BAR frame to execute the existing BA mechanism. The BA Repeat Indication subfield indicates that the receiving device can send the ML-BA frame only on one link, or redundantly send the ML-BA frame simultaneously on all links transmitting data frames.

[0028] After receiving an ML-BAR frame, the multi-link receiving device, according to the indication, feeds back ML-BA frames on one or more links, indicating the reception status of each A-MPDU on each link. Depending on the multi-link device architecture, ML-BA frames are divided into two types. In a multi-MACMLO (Multi-Link Operation) architecture, the designed ML-BA frame utilizes a reserved field in the BA Control field to define a Multi-Link BA Indication subfield, used to indicate whether the BA frame carries only block acknowledgment information for this link or multi-link block acknowledgment information. The data frame reception status information of the ML-BA frame is represented by the BAInformation field. In existing protocols, the BA Information field of the BA frame contains one or more independent information structures; for example, if the data frame corresponds to multiple TIDs, each independent information structure is identified by a TID. To better illustrate the multi-link transmission indication method of this application embodiment, each independent information structure is referred to as a block acknowledgment information field segment. Depending on the different bit values ​​of the BA Type subfield in the BA Control field of the ML-BA frame, the specific information contained in the block acknowledgment information field segment in the embodiments provided in this application differs. To carry specific link information, a link value subfield is added to the block acknowledgment information field segment, defined using the Reserved field, or added by extending existing fields. Each block acknowledgment information field segment corresponds to a block acknowledgment bitmap (BA Bitmap) subfield. A multi-MAC block acknowledgment additional bitmap (Multi-MAC BA AddBitmap) subfield is added after this subfield to indicate whether the data frame reception error is due to decoding failure or the inability to receive the data frame.

[0029] In a single-MAC MLO architecture, the designed ML-BA frame also utilizes the Reserved field in the BA Control field to define the Multi-Link BA Indication subfield. The BA Information field, which contains data frame reception status information, includes one or more block acknowledgment information field segments. Each block acknowledgment information field segment corresponds to a BA Bitmap subfield. A Single-MAC BA AddBitmap subfield is added after this subfield to indicate whether the data frame reception error is due to decoding failure or the inability to receive the data frame, as well as the link information corresponding to the erroneous data frame.

[0030] Example:

[0031] I. Multi-link Wireless Communication Systems

[0032] The network device of this invention can be a device for communicating with a terminal, or it can be a relay station, access point, vehicle-mounted device, wearable device, network device in a 5G network, network device in a future 6G network, or network device in a PLMN network, etc. Multiple links can be different frequency bands or different sub-channels of the same frequency band; they can be low-frequency links or high-frequency links, such as millimeter-wave bands. Figure 1 This is a schematic diagram illustrating an application scenario of a multi-link transmission indication method and system. An access point (AP) can be a communication server, router, switch, base station, or any of the aforementioned network devices. A station (STA) can be a mobile phone, computer, or any of the aforementioned terminals.

[0033] Figure 1 In the multi-link wireless communication system illustrated, the base station is represented by an AP (Access Point) and the STA by a mobile phone. The communication equipment in a multi-link wireless communication system can be a wireless communication device that supports parallel transmission across multiple links, such as a multi-link device (MLD). Compared to devices that only support single-link transmission, multi-link devices have higher transmission efficiency and higher throughput. A multi-link device includes one or more affiliated STAs. An affiliated STA is a logical site that can operate on a single link. The affiliated site can be an AP or a non-AP STA. For ease of description, this embodiment refers to a multi-link device with an affiliated AP as a multi-link AP, a multi-link AP device, or an AP multi-link device (AP MLD), and a multi-link device with an affiliated non-AP STA as a multi-link STA, a multi-link STA device, or a STA multi-link device (non-AP MLD).

[0034] II. Multi-link device structure description

[0035] Figure 2 This is a schematic diagram illustrating the relationship between multiple link devices in this embodiment. Figure 2 The AP MLD shown can consist of multiple APs, and the STA MLD can consist of multiple STAs. Each AP in the AP MLD is associated with a corresponding STA in the STA MLD to achieve multi-link communication. For example... Figure 2As shown, AP1 to AP3 in the AP MLD operating on links 1, 2, and 3 are associated with STA1 to STA3 in the STAMLD, respectively. This association allows each AP in the AP MLD to establish a connection with its corresponding STA in the STAMLD on its respective link. Simultaneously, to achieve multi-link communication between the two MLDs, a MAC layer multi-link operation carrier aggregation solution needs to be implemented within the MLD. According to the multi-link reference model given in 802.11be, the MAC layer can be divided into an upper MAC layer (UMAC, Upper MAC) and a lower MAC layer (LMAC, Lower MAC). These two MAC layers allow data frames to be transmitted simultaneously on multiple links. The UMAC is a common part of all interfaces, responsible for link management. It buffers traffic from the upper layer before allocating it to a specific LMAC interface for transmission, and also buffers traffic from the LMAC interface before passing it to the upper layer. The UMAC also supports seamless switching between links to minimize access latency and achieve efficient load balancing. The LMAC, as a separate interface part under the UMAC, performs link-specific functions through its own channel access methods and parameters.

[0036] III. Relevant Concepts in the Embodiments of this Invention

[0037] The Basic Acknowledgment (BA) mechanism in existing Wi-Fi networks was first proposed in the 802.11e standard and refined in the 802.11n standard. The BA mechanism has evolved further since 802.11n, for example, with Multi-STA type BA frames. The BA mechanism improves channel efficiency by aggregating multiple acknowledgments into a single frame. It is initiated by exchanging Add Block Acknowledgment (ADDBA) request frames and ADDBA response frames, or by using an unsolicited block ack extension mechanism. The transmitting device sends an ADDBA request frame, and the receiving device responds with an ADDBA response frame, thus successfully establishing the BA mechanism / session between the transmitting and receiving devices. During data transmission, the transmitting device sends multiple MPDUs to the receiving device at SIFS (Short Interframe Space) intervals, or aggregates multiple MPDUs into a single A-MPDU before sending it to the receiving device. Acknowledgment strategies for transmitted data are divided into explicit BAR strategies and implicit BAR strategies. In the explicit BAR strategy, the transmitting device sends a BAR frame to request a BA frame response after the last data transmission is complete. In the implicit BAR strategy, the receiving device directly sends a BA frame after the last data transmission is complete without requiring a BAR frame request. To generate a BA frame indicating the reception status of each MPDU on multiple links on a specified link, it may be necessary to wait for all links to complete transmission before indicating the ML-BA frame transmission link. The explicit BAR strategy can carry the relevant indication information for multi-link block acknowledgments in the ML-BAR frame to instruct the receiving device to send an ML-BA frame; while the implicit BAR strategy can default to sending an ML-BA frame through negotiation between the transmitting and receiving devices. The frame structure design of the ML-BA frame is similar under both BAR strategies.

[0038] IV. Technical Problem to be Solved by the Invention

[0039] In the scheme designed in this invention, the transmitting device needs to indicate redundant transmission link information in the multi-link block acknowledgment frame in the BAR frame. The receiving device, based on the information carried in the received BAR frame, replies with a BA frame on one or more specified links, carrying the reception status of all link A-MPDUs and indicating the specific reception error type. This invention specifically designs the ML-BAR frame and ML-BA frame used in the above multi-link communication process.

[0040] V. A method and system for indicating multi-link transmission

[0041] The following implementation process and frame structure design are based on the IEEE 802.11ax standard, but are not limited to the 802.11ax standard; they are also applicable to Wi-Fi 7 and subsequent Wi-Fi standards. The invention will be further described in detail with reference to the accompanying drawings and specific implementation methods.

[0042] Figure 3 This is a schematic diagram illustrating the interaction of the multi-link transmission indication method. This method is based on an explicit BAR strategy and is explained from the perspective of frame interaction between the BAR frame sending device and the BA frame sending device. The multi-link device, acting as the data sender, sends a BAR frame to the data receiver to request feedback on the data reception status. Upon receiving the BAR frame, the multi-link device, acting as the data receiver, sends back an ML-BA frame carrying the data reception status of multiple links on one or more links, based on the indication information.

[0043] Figure 4 The diagram shows a multi-link block acknowledgment request frame structure according to this embodiment. As a newly designed BAR frame, the ML-BAR frame in this embodiment requires the use of the Reserved field in the BAR Control field to define the Multi-Link BAR Indication subfield and the BA Repeat Indication subfield. The Multi-Link BAR Indication subfield indicates that, in addition to the original BAR Type indication, this frame, as an ML-BAR frame, requests the multi-link receiving device to send an ML-BA frame carrying multi-link block acknowledgment information, or, as a general BAR frame, executes the existing BA mechanism. To increase the probability of the device sending the BAR frame successfully receiving the BA frame, the BA Repeat Indication subfield instructs the receiving device to send the ML-BA frame only on one link, or to redundantly send the ML-BA frame simultaneously on all links transmitting data frames, such as... Figure 5 As shown below. The functions and detailed definitions of the Multi-Link BAR Indication subfield and the BA Repeat Indication subfield are explained in the following text:

[0044] 1. Multi-Link BAR Indication subfield

[0045] This field indicates whether the multi-link receiving device receiving the BAR frame is suitable for transmitting ML-BA frames. The field length is 1 bit. When the value of this field is 1, it means that the receiving device is suitable for transmitting ML-BA frames. When the value of this field is 0, it means that it is not suitable, which is compatible with the existing BA mechanism.

[0046] 2. BA Repeat Indication subfield

[0047] This field indicates whether the receiving device sending the BAR frame transmits the ML-BA frame on only one link, or redundantly transmits the ML-BA frame simultaneously on all links transmitting data frames. The field length is 1 bit. When the field value is 1, it means that the receiving device redundantly transmits the ML-BA frame simultaneously on all links transmitting data frames. When the field value is 0, it means that it is transmitted only on the link receiving the ML-BAR frame.

[0048] Based on the MAC layer carrier aggregation solution for multi-link devices, the architecture of multi-link devices can be divided into two types: single-MAC MLO architecture and multi-MAC MLO architecture. Figure 6 As shown. In both architecture types, to manage the MAC layer and the physical (PHY, Physical) layer, each device has a multi-link management entity, mainly responsible for collecting layer-related states from various layer management entities and setting relevant parameter values. In the multi-MAC MLO example architecture, the MAC layer is divided into two sub-layers: the UMAC layer and the LMAC layer. Under the multi-link management entity, the unified UMAC layer implements the main functions of the MAC layer of the multi-link device. Each LMAC layer has its own independent MAC address and implements functions such as channel state monitoring. In the single-MAC MLO example architecture, only one MAC address serves as the physical identifier of the device. For the multi-link management entity, the transmission between multiple links is transparent. When the device receives an ML-BAR frame, this embodiment provides a multi-link block acknowledgment frame that can be used in the single-MAC MLO architecture and an ML-BA frame that can be used in the multi-MAC MLO architecture. The ML-BA frame in the multi-MAC MLO architecture differs depending on the bit value of the BA Type subfield in the BA Control field. This application provides several exemplary embodiments.

[0049] Figure 7The diagram shows the ML-BA frame structure under the multi-MAC MLO architecture of this embodiment, where the BA Type subfield bit value is 2, indicating that the ML-BA frame type is Compressed BA. As a novel BA frame, this embodiment's ML-BA frame, in addition to defining the Multi-Link BAIndication subfield using the Reserved field in the BA Control field, also requires adding a Per LID Info subfield and a Multi-MAC BA AddBitmap subfield to each block acknowledgment information field segment. The Per LID Info subfield defines a Link Value subfield to indicate link information, and the Multi-MAC BA AddBitmap subfield indicates whether the data frame reception error is due to decoding failure or the inability to receive the data frame. The functions and detailed definitions of the Multi-Link BA Indication subfield, Link Value subfield, and Multi-MAC BA AddBitmap subfield are described below:

[0050] 1. Multi-Link BA Indication Subfield

[0051] This field indicates whether the BA frame contains receive status information of each MDPU in the A-MPDU transmitted on multiple links. The field length is 1 bit. When the value of this field is 1, it means that the BA frame contains receive status of data frames from multiple links; when the value of this field is 0, it means that it only contains the data from the current link.

[0052] 2. Link Value subfield

[0053] This field indicates the link sequence number corresponding to the segment in the Block Acknowledgment Information field of the BA Information field. The field length is 4 bits and can represent up to 16 links. For example, if this field is set to 0011, it means that the corresponding link sequence number is 3. If the Multi-Link BA Indication subfield value is 0, that is, the receiving device is not suitable for sending ML-BA frames, then there is no need to carry link information through the Link Value subfield.

[0054] 3. Multi-MAC BA AddBitmap subfield

[0055] When the Multi-Link BA Indication subfield value is 1, indicating that the receiving device is suitable for sending ML-BA frames, the Multi-MAC BA AddBitmap subfield is added after the existing BA Bitmap subfield. This field indicates, in bitmap form, whether the data frame reception status in the BA Bitmap subfield is a decoding failure or the inability to receive the data frame. The field length is variable, and this field is used as a schematic diagram of continuous Bitmap sequence encoding as shown in the figure. Figure 8 As shown. The BA Bitmap uses 1 bit to indicate the reception status of a corresponding MPDU. A 1 bit indicates successful MPDU reception, and a 0 bit indicates unsuccessful reception. The Multi-MAC BA AddBitmap uses 1 bit to indicate the error reception status when the BA Bitmap is 0. A 1 bit indicates data frame decoding failure, and a 0 bit indicates that the data frame was not received.

[0056] Figure 9 The diagram illustrates the ML-BA frame structure under the second multi-MAC MLO architecture of this embodiment, where the BA Type subfield bit value is 3, indicating that the ML-BA frame type is Multi-TID BA. The difference from the Compressed BA type ML-BA lies in the indication method of the Link Value subfield. The protocol defines that the block acknowledgment information field segment in this type of BA frame includes a Per TID Info subfield. After using the Reserved field within this subfield to define the LinkValue subfield, it can be redefined as a Per TID LID Info subfield.

[0057] Figure 10 The diagram shows the third multi-MAC MLO architecture in this embodiment, where the BA Type subfield bit value is 11, indicating the ML-BA frame type as Multi-STA BA, and the ML-BA frame structure that can be adopted. The difference from the Compressed BA type ML-BA lies in the different indication method of the Link Value subfield. The protocol defines that the block acknowledgment information field segment in this type of BA frame includes a Per AID TID Info subfield. After expanding this subfield to add a LinkValue subfield, it can be redefined as a Per AID TID LID Info subfield.

[0058] The link information indication methods described above, which are added to the ML-BA frame by adding new information, defining it using the Reserved field, or extending the original field, include, but are not limited to, the embodiments described above.

[0059] Figure 11 The diagram illustrates a single-MAC MLO architecture in this embodiment, where the BA Type subfield bit value is 3, indicating that the ML-BA frame type is Multi-TID BA. This embodiment provides a multi-link block acknowledgment frame, a novel type of BA frame, which includes the same indication method for the reception status information of each MDPU in the A-MPDU transmitted on multiple links as the BA frame in the multi-MAC MLO architecture. Since there is only a single MAC address, successfully received data frames on multiple links do not need to distinguish link sequence numbers, while incorrectly received data frames need to indicate the link sequence number to better indicate the retransmission link / strategy. Therefore, a Single-MAC BA AddBitmap subfield is added after the BA Bitmap subfield in each block acknowledgment information field segment to indicate whether the incorrect reception status of the data frame is decoding failure or that the data frame was not received, as well as the link information corresponding to the incorrectly received data frame. Depending on the number of links, the number of bits required to encode the link information corresponding to the MPDU with a received error in the Single-MACBA AddBitmap subfield varies. Therefore, an AddBitmap Link Coding Granularity subfield is added to the Reserved field of the BA Control field to indicate the encoding granularity of the MPDU link information in the Single-MAC BA AddBitmap subfield according to the number of links. The functions and detailed definitions of the AddBitmap Link Coding Granularity subfield and the Single-Link BA Indication subfield are explained below:

[0060] 1. Add Bitmap Link Coding Granularity subfield

[0061] This field indicates the number of bits required to encode the MPDU link information corresponding to the received error in the Single-MAC BA AddBitmap subfield. The field length is 2 bits. The number of bits required to encode the MPDU link information corresponding to the received error is equal to the value of the AddBitmap Link Coding Granularity subfield plus 1. If the Multi-Link BA Indication subfield value is 0, it means that the receiving device is not suitable for sending ML-BA frames, and there is no need to indicate the number of bits for encoding the link information through this field.

[0062] 2. Single-MAC BA AddBitmap subfield

[0063] When the Multi-Link BA Indication subfield value is 1, indicating that the receiving device is suitable for sending ML-BA frames, a Single-MAC BA AddBitmap subfield is added after the original BA Bitmap subfield. This field indicates, in bitmap form, whether the reception status of the data frame error in the BA Bitmap subfield is decoding failure or no reception of the data frame, as well as the link information corresponding to the erroneous data frame. The field length is variable. Specifically, the AddBitmap Link Coding Granularity subfield within the Single-MAC BA AddBitmap subfield takes a value plus 2 bits to indicate the error reception status information and link information of the received erroneous MPDU corresponding to one BA Bitmap. This field is illustrated as a continuous Bitmap sequence encoding diagram as shown below. Figure 12 As shown in the diagram, the AddBitmap Link Coding Granularity subfield has a value of 1. The first bit indicates the reception status information of the corresponding erroneous MPDU; a value of 1 indicates data frame decoding failure, and a value of 0 indicates that the data frame was not actually received. Subsequent bits indicate the link sequence number of the corresponding erroneous MPDU. When the AddBitmap LinkCoding Granularity subfield value is at its maximum value of 3, it can indicate the sequence numbers of up to 16 different links. If the Multi-Link BA Indication subfield value is 0, and the receiving device is not suitable for sending ML-BA frames, then a single bit in the Single-MACBA AddBitmap subfield can be used to indicate the reception status information of the corresponding received erroneous MPDU.

Claims

1. A multi-link transmission indication method, characterized in that, For uplink and downlink multi-link communication scenarios, when the multi-link data transmitter sends A-MPDUs from multiple links to the same data receiver, the data receiver can carry block acknowledgment information of A-MPDUs from multiple links in a single multi-link BA frame. Alternatively, it can send multi-link BA frames on only one link to indicate whether each MPDU in each A-MPDU on multiple links has been correctly received, or redundantly send multiple link BA frames simultaneously on multiple links to improve the transmission reliability of BA frames. Furthermore, after the block acknowledgment field indicating whether each MPDU was correctly received or failed, a variable-length field indicating the MPDU reception failure type is added to distinguish between data frame decoding failure and data frame loss status information. In the multi-link transmission scenario, when the multi-link device is a multi-MAC MLO architecture, the multi-link BA frame carries multiple block acknowledgment information bitmaps corresponding to each link, as well as link information of the corresponding link block acknowledgment bitmaps, and adds a bitmap explaining the reception failure type of each MPDU after the block acknowledgment bitmap. The multi-link device sends a multi-link BA frame containing a multi-link block acknowledgment indication field, a corresponding link block acknowledgment bitmap link sequence number field, and an additional bitmap field in the block acknowledgment bitmap corresponding to the MPDU reception failure type. The multi-link block acknowledgment indication field is used to indicate whether the acknowledgment information reply for each A-MPDU block on multiple links has been completed on one link. The corresponding link block acknowledgment bitmap link sequence number field is used to indicate the link information corresponding to the block acknowledgment bitmap. The bitmap field in the block acknowledgment bitmap corresponding to the MPDU reception failure type is used to indicate whether the data frame reception error status is a decoding failure or the ability not to receive the data frame.

2. The multi-link transmission indication method according to claim 1, characterized in that, When a multi-link data transmitter instructs a data receiver to simultaneously send a multi-link BA frame on one or more links, indicating whether each MPDU in the A-MPDU transmitted on the multiple links has been correctly received, a multi-link BAR frame needs to be sent. The multi-link block acknowledgment frame redundancy transmission indication field is used to indicate whether the data receiver needs to repeatedly send the multi-link BA frame on multiple links.

3. The multi-link transmission indication method according to claim 2, characterized in that, The BAR frame includes a multi-link block acknowledgment request indication field for indicating whether the acknowledgment information reply for each A-MPDU block on multiple links can be completed on one link, and a multi-link block acknowledgment frame redundancy transmission indication field for indicating whether the receiving device should repeatedly transmit multi-link BA frames on multiple links.

4. The multi-link transmission indication method according to claim 1, characterized in that, In the multi-link transmission scenario, when the multi-link device is a single MAC MLO architecture, the multi-link BA frame carries a bitmap including multiple link block acknowledgment information. After the block acknowledgment bitmap, a bitmap is added to explain the reception failure type of each MPDU and the corresponding link information of the reception failure MPDU. The number of bits required for the link information is determined by the specific link information encoding granularity indication information. The multi-link device sends a multi-link BA frame containing a multi-link block acknowledgment indication field, an additional bitmap link information encoding granularity field, and an additional bitmap field in the block acknowledgment bitmap indicating the MPDU reception failure type and the corresponding link sequence number of the MPDU reception failure. The multi-link block acknowledgment indication field indicates whether the acknowledgment information reply for each A-MPDU block on multiple links is completed on one link. The additional bitmap link information encoding granularity field indicates the number of bits required for encoding the corresponding MPDU link information in the additional bitmap. The additional bitmap field in the block acknowledgment bitmap indicating the MPDU reception failure type and the corresponding link sequence number of the MPDU reception failure indicates whether the data frame reception error is a decoding failure or the inability to receive the data frame, as well as the link information corresponding to the erroneous data frame.

5. A multi-link transmission indication system, characterized in that, An application of the multi-link transmission indication method according to any one of claims 1 to 4 includes an access point and a station in a multi-link communication scenario; both the station and the access point can operate on multiple links and become a data sender or a data receiver; the data sender sends data to the data receiver on multiple links within a predetermined data transmission opportunity time; after data transmission is completed on multiple links, the data sender sends a multi-link type block acknowledgment request frame to the data receiver on a specific link; the data receiver sends a multi-link type block acknowledgment frame that simultaneously includes the data reception status of multiple links on only one specific link, or redundantly sends multi-link type block acknowledgment frames on multiple links simultaneously; in the multi-link type block acknowledgment frame, different link information indication methods are provided according to the multi-link device architecture, and information about the status type capability of data frame error reception is carried after the block acknowledgment information.

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