Method for signaling information exchange in wireless local area network, and communication apparatus

Abstract

To provide a communication method to be applied to a multi-link device in a wireless local area network (WLAN), and an apparatus.SOLUTION: A method to be applied to a WLAN includes transmitting, by a reporting access point (AP), a management frame to a station. A reporting AP belongs to a first AP multi-link device (MLD). A reported AP belongs to a multiple BSSID set. The management frame includes MLD information. The MLD information carries, by using different types of MLD elements, such as a formal MLD element, a virtual MLD element, and a multiple BSSID element, for example, information on another AP in the MLD to which the AP belongs, information on the multiple BSSID set to which the AP belongs, and information on an AP in a multiple BSSID set including the other AP in the MLD to which the AP belongs. The station obtains information on the reporting AP and other information on the reported AP based on the management frame.SELECTED DRAWING: Figure 10A

Description

[Technical field]

[0001] The present application relates to the field of communication technology, and in particular to a method and communication device for exchanging signaling information in a wireless local area network. [Background technology]

[0002] To significantly improve the service transmission rate of WLAN systems, the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax standard further uses Orthogonal Frequency Division Multiple Access (OFDMA) technology based on the existing Orthogonal Frequency Division Multiplexing (OFDM) technology. OFDMA technology supports multiple nodes to transmit and receive data simultaneously, achieving multi-station diversity gain. During the formulation of 802.11ax in 2017, the Federal Communications Commission (FCC) released a new free frequency band from 5925 to 7125 MHz, hereafter referred to as 6 GHz. Therefore, 802.11ax standard workers will extend the operating range of 802.11ax-compliant devices from 2.4 GHz and 5 GHz to 2.4 GHz, 5 GHz, and 6 GHz in the 802.11ax Project Authorization Requests (PARs).

[0003] IEEE 802.11 next-generation Wi-Fi protocol (extremely high throughput, EHT) devices require forward compatibility. Therefore, these devices are also compatible with the operating spectrum of 802.11ax-compliant devices, specifically supporting the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. The channel division is based on the newly opened free 6 GHz frequency band, and the supportable bandwidth may exceed the maximum bandwidth of 160 MHz supported at 5 GHz, and may be, for example, 320 MHz. In addition to utilizing the ultra-high bandwidth, the IEEE 802.11ax next-generation Wi-Fi extremely high throughput protocol can also increase the peak throughput, for example, by increasing the number of streams to 16, by cooperating with multiple frequency bands (2.4 GHz, 5 GHz, and 6 GHz), or in other ways. In the same frequency band, the peak throughput can be further increased by cooperation of multiple channels, or in other ways. This reduces the transmission delay of the service. In the following, multiple frequency bands and multiple channels are collectively referred to as multiple links. In 802.11ax and earlier Wi-Fi standards, multiple links with the same operating frequency band as 802.11ax are configured, but typically a different Basic Service Set (BSS) is configured for each of the multiple links. Communication with stations in the BSS to which the link belongs can be performed only on one link at a time.

[0004] The main function of 802.11ax and its predecessor Multiple Basic Service Set Identifier (BSSID) technology is to virtualize one physical AP into multiple logical APs, i.e., to form multiple virtual networks. Each virtual network is used to manage different stations. Similar to AP products in current Wi-Fi scenarios, an AP can be virtualized into a reporting AP (home AP) and a guest AP (guest AP).

[0005] How to apply the Multiple BSSID technology to a multi-link device to provide the functionality of multiple virtual networks is a technical topic being studied by those skilled in the art. Summary of the Invention

[0006] The embodiments of the present application disclose a method for exchanging signaling information in a WLAN and related devices.

[0007] According to a first aspect, an embodiment of the present application provides a signaling information exchange method in a WLAN, including: An access point (AP) generates a management frame. The AP belongs to a first AP multilink device (MLD). The management frame includes MLD information. The MLD information includes a first MLD element. Sub-elements of the first MLD element are used to convey information about other APs in the first MLD to which the AP belongs. The first MLD element includes type information indicating an MLD element type. The access point transmits the management frame.

[0008] According to a second aspect, an embodiment of the present application provides a signaling information exchange method in a WLAN, including: A station receives a management frame transmitted by an access point (AP). The AP belongs to a first AP multi-link device (MLD). The management frame includes MLD information. The MLD information includes a first MLD element. Sub-elements of the first MLD element are used to convey information about another AP in the first MLD to which the AP belongs. The MLD element includes type information indicating an MLD element type. The station (AP) obtains information about the other AP in the first MLD to which the AP belongs based on the management frame.

[0009] According to a third aspect, there is provided a communication device in a wireless local area network (WLAN), comprising: a processing unit configured to generate a management frame, where an AP belongs to a first AP multi-link device (MLD), the management frame includes MLD information, the MLD information includes a first MLD element, a sub-element of the first MLD element is used to convey information about another AP in the first MLD to which the AP belongs, and the first MLD element includes type information indicating an MLD element type; a transceiver unit configured to receive and transmit said management frames; Includes.

[0010] According to a fourth aspect, a communication device for a wireless local area network (WLAN) includes a transceiver unit configured to receive a management frame transmitted from an access point (AP), the AP belonging to a first AP multi-link device (MLD), the management frame including MLD information, the MLD information including a first MLD element, a sub-element of the first MLD element being used to convey information about another AP in the first MLD to which the AP belongs, the MLD element including type information indicating a type of the MLD element; and a processing unit configured to obtain information about the other AP in the first MLD to which the AP belongs based on the management frame.

[0011] According to a fifth aspect, there is provided a communications device including a processor and a memory, the memory storing instructions which, when executed by the processor, cause the communications device to generate a management frame, an AP belongs to a first AP multi-link device (MLD), the management frame includes MLD information, the MLD information includes a first MLD element, sub-elements of the first MLD element are used to convey information about another AP in the first MLD to which the AP belongs, the first MLD element further includes type information indicating an MLD element type, and is enabled to transmit the management frame.

[0012] According to a sixth aspect, there is provided a communications device including a processor and a memory, the memory storing instructions which, when executed by the processor, cause the communications device to: receive a management frame transmitted from an access point (AP), the AP belonging to a first AP multi-link device (MLD), the management frame including MLD information, the MLD information including a first MLD element, sub-elements of the first MLD element being used to convey information about another AP in the first MLD to which the AP belongs, the MLD element including type information indicating a type of MLD element; Based on the management frame, the AP is enabled to obtain information about the other APs in the first MLD to which it belongs.

[0013] According to the flexible signaling structure provided in the present application, one or more MLD elements and MLD elements included in the Multiple BSSID element are used to describe information about one or more APs in a multi-AP multi-link device, helping a station select a suitable AP or AP MLD for association. The signaling structure of MLD information provided in this embodiment of the present application is simple and flexible.

[0014] In an implementation of the method or device according to any of the above aspects, the MLD element further includes a common control field, in which the type information indicating the element type of the MLD element is included. In this embodiment of the present application, the type information indicating the MLD element type is carried within the MLD element, so that the station can determine the type of the MLD based on the information and determine the relationship between all MLDs in a multi-AP multi-link device and the structure of the MLD.

[0015] In an implementation of the method or apparatus according to any of the above aspects, the element type includes a formal MLD element and a virtual MLD element, and the type information specifically includes a virtual MLD field indicating whether the MLD element is a virtual MLD element.

[0016] In a method or apparatus implementation of any of the above aspects, the virtual MLD field comprises 1 bit.

[0017] If the MLD element is the virtual MLD element, the virtual MLD field is set to a first value.

[0018] If the MLD element is an official MLD element, the virtual MLD field is set to a second value.

[0019] In a method or apparatus implementation of any of the above aspects, the element types include a formal MLD element, a virtual MLD element, and a special MLD element, and the type information includes a virtual MLD field indicating whether the MLD element is a virtual MLD element and a special MLD resource indicating whether the MLD element is a special MLD element.

[0020] In a method or device implementation of any of the above aspects, the virtual MLD field includes 1 bit. The special MLD field includes 1 bit. If the MLD element is the virtual MLD element, the virtual MLD field is set to a first value and the special MLD field is set to a second value. If the MLD element is the special MLD element, the virtual MLD field is set to a second value and the special MLD field is set to the first value. If the MLD element is a formal MLD element, the virtual MLD field is set to a second value and the special MLD field is set to the second value.

[0021] In a method or device implementation of any of the above aspects, the MLD element further includes an MLD common information field. The common control field further includes an MLD address present field indicating whether an MLD address field is present in the MLD common information field. The MLD address field conveys an identifier of the first MLD.

[0022] In a method or device implementation of any of the above aspects, if the type information indicates that the MLD element is the virtual MLD element, the MLD common information field includes the MLD address field, and if the type information indicates that the MLD element is the official MLD element, the MLD common information field includes the MLD address field.

[0023] In a method or apparatus implementation of any of the above aspects, if the type information indicates that the MLD element is the special MLD element, the MLD common information field does not include the MLD address field.

[0024] In an implementation of the method or device of any of the above aspects, if the other APs in the first MLD belong to a second Multiple BSSID set and the other APs in the second Multiple BSSID set belong to a second MLD, the MLD information further includes a second MLD element, a sub-element of the second MLD element conveying information about APs in the second MLD.

[0025] In an implementation of the method or device of any of the above aspects, if the AP belongs to a first Multiple BSSID set, the MLD information further includes a first Multiple BSSID element, which includes information about non-transmitting APs in the first Multiple BSSID set.

[0026] In an implementation of the method or device of any of the above aspects, if the non-transmitting AP in the first Multiple BSSID set belongs to a 3MLD, the Multiple BSSID element further includes a 3MLD element, whose sub-elements convey information about other APs in the 3MLD.

[0027] In an implementation of the method or device of any of the above aspects, if the other AP of the first MLD belongs to a third Multiple BSSID set and the AP of the third Multiple BSSID set does not belong to the MLD, the MLD information further includes a fourth MLD element, a sub-element of the fourth MLD element conveying information about the AP.

[0028] In a method or device implementation of any of the above aspects, the first MLD element is an authoritative MLD element, and the type information of the first MLD element indicates that the first MLD element is the authoritative MLD element.

[0029] In a method or apparatus implementation of any of the above aspects, the second MLD element is a virtual MLD element, and type information in the second MLD element indicates that the second MLD element is the virtual MLD element.

[0030] In a method or device implementation of any of the above aspects, the third MLD element is an authoritative MLD element, and type information in the second MLD element indicates that the second MLD element is the authoritative MLD element.

[0031] In a method or device implementation of any of the above aspects, the fourth MLD element is a special MLD element, and type information of the fourth MLD element indicates that the fourth MLD element is the special MLD element.

[0032] The communication device of the third, fourth, fifth and sixth aspects may be a chip. The processing unit may be a processing circuit of the chip. The transceiver unit may be an input / output interface circuit. The processing circuit may be configured to process signaling or data information provided by the input / output interface circuit. The input / output interface circuit may be configured to input / output the data or signaling information of the chip.

[0033] According to a seventh aspect of an embodiment of the present application, there is provided a computer readable storage medium storing computer program code which, when executed on a processor, enables the processor to perform the method of the first aspect, the second aspect and any of the corresponding possible implementations.

[0034] According to an eighth aspect of an embodiment of the present application, there is provided a computer program product, the program product storing a computer program (instructions) for execution by the aforementioned processor, the computer program being enabled to execute the method of the first aspect, the second aspect and any of the corresponding possible implementations when executed on the processor.

[0035] According to a ninth aspect of an embodiment of the present application, there is provided a communication device. The device includes a processor and may further include a transceiver and a memory. The transceiver is configured to transmit and receive information or to communicate with another network element. The memory is configured to store a computer program (instructions). The processor is configured to execute the computer program to perform the method in any of the first aspect, the second aspect, and corresponding possible implementations.

[0036] According to a tenth aspect of an embodiment of the present application, a communication device is provided. The device may be in a product form of a chip. The structure of the device may include a processor and may further include a memory. The memory is coupled to the processor and configured to store programs (instructions) and data required by the device. The processor is configured to execute the computer program stored in the memory to support the communication device to execute the method in any of the first aspect, the second aspect, and corresponding possible implementations. Optionally, the memory may be located within the processor and may be an internal storage. Alternatively, the processor may be external to the processor and coupled to the processor and may be an external storage.

[0037] According to an eleventh aspect of an embodiment of the present application, there is provided a communication device. The device may be in a product form of a chip. The structure of the device includes a processor and an interface circuit. The processor is configured to communicate with another device through a receiving circuit and enable the communication device to perform the method in any of the first aspect, the second aspect, and corresponding possible implementations.

[0038] According to a twelfth aspect of an embodiment of the present application, there is provided a communication device, enabled to perform the method of the first aspect, the second aspect and any of the corresponding possible implementations. [Brief description of the drawings]

[0039] The following describes the accompanying drawings used in the embodiments of this application.

[0040] [Figure 1] FIG. 1 is a schematic diagram of the structure of a communication system according to an embodiment of the present application;

[0041] [Figure 2A] 1 is a schematic diagram of a structure of a multi-link device according to an embodiment of the present application;

[0042] [Figure 2B]FIG. 2 is a schematic diagram of another structure of a multi-link device according to an embodiment of the present application.

[0043] [Figure 2C] FIG. 2 is a schematic diagram of another structure of a multi-link device according to an embodiment of the present application.

[0044] [Figure 3A] FIG. 2 is a schematic diagram of multi-link communication according to an embodiment of the present application;

[0045] [Figure 3B] FIG. 2 is another schematic diagram of multi-link communication according to an embodiment of the present application;

[0046] [Figure 4] 2 is a schematic diagram of an iteration of a communication method applied to a multi-link device in a WLAN according to an embodiment of the present application;

[0047] [Diagram 5] 1 is a schematic diagram of the structure of a multi-AP multi-link device according to an embodiment of the present application;

[0048] [Figure 6A] FIG. 2 is a schematic diagram of the structure of an MLD element according to an embodiment of the present application.

[0049] [Figure 6B] FIG. 2 is a schematic diagram of the structure of another MLD element according to an embodiment of the present application.

[0050] [Figure 6C] FIG. 2 is a schematic diagram of a structure of yet another MLD element according to an embodiment of the present application.

[0051] [Figure 7] FIG. 2 is a schematic diagram of the structure of sub-elements of an MLD element according to an embodiment of the present application.

[0052] [Figure 8A] FIG. 2 is a schematic diagram of the structure of another multi-AP multi-link device according to an embodiment of the present application;

[0053] [Figure 8B] FIG. 2 is a schematic diagram of the structure of yet another multi-AP multi-link device according to an embodiment of the present application;

[0054] [Figure 9A] 2 is a schematic diagram of a structure of a management frame according to an embodiment of the present application;

[0055] [Figure 9B] FIG. 2 is a schematic diagram of a structure of another management frame according to an embodiment of the present application;

[0056] [Figure 9C] 13 is a schematic diagram of a structure of yet another management frame according to an embodiment of the present application;

[0057] [Figure 9D] 13 is a schematic diagram of a structure of yet another management frame according to an embodiment of the present application;

[0058] [Figure 10A] 2 is a schematic flowchart of a signaling information exchange method for a multi-AP multi-link device according to an embodiment of the present application;

[0059] [Figure 10b] 4 is a schematic flowchart of another signaling information exchange method for a multi-AP multi-link device according to an embodiment of the present application;

[0060] [Figure 11] 2 is a schematic flowchart of a signaling information exchange method for a multi-AP multi-link device according to an embodiment of the present application;

[0061] [Figure 12] FIG. 2 is a schematic diagram of a structure of a Multiple BSSID element according to an embodiment of the present application;

[0062] [Figure 13A]13 is a schematic diagram of yet another management frame structure according to an embodiment of the present application;

[0063] [Figure 13B] 13 is a schematic diagram of a structure of yet another management frame according to an embodiment of the present application;

[0064] [Figure 14A] FIG. 2 is a schematic diagram of a structure of a Reduced Neighbor Report (RNR) element according to an embodiment of the present application;

[0065] [Figure 14B] 1 is a schematic diagram of the structure of a TBTT information field of an RNR element according to an embodiment of the present application;

[0066] [Figure 14C] FIG. 13 is a schematic diagram of the structure of another TBTT information field of an RNR element according to an embodiment of the present application.

[0067] [Figure 15] FIG. 1 is a schematic diagram of a configuration of a communication device according to an embodiment of the present application.

[0068] [Figure 16] FIG. 2 is a schematic diagram of a configuration of another communication device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] The following describes the related art in the present application, and then describes the embodiments of the present application with reference to the accompanying drawings.

[0070] An embodiment of the present application provides a communication method applied to a wireless communication system. The wireless communication system may be a wireless local area network (WLAN) or a cellular network. The method may be implemented by a communication device in the wireless communication system or a chip or processor in the communication device. The communication device may be a wireless communication device that supports simultaneous transmissions on multiple links. For example, the communication device is called a multi-link device or a multi-band device. For example, in a wireless local area network, the communication device supports communication using an IEEE 802.11 series protocol, which includes 802.11be, 802.11ax, or 802.11a / b / g / n / ac.

[0071] 1. Multi-link device (MLD), also known as multi-band device.

[0072] The multi-link device MLD includes one or more home stations, and the home station is a logical station. In the embodiment of the present application, "the multi-link device includes a home station" is also simply written as "the multi-link device includes a station". The home station may be an access point (AP) or a non-access point station (non-AP STA). For ease of explanation, in the present application, a multi-link device having an AP as a home station may be called a multi-link AP, a multi-link AP device, or an AP multi-link device, and a multi-link device having a non-AP STA as a home station may be called a multi-link STA, a multi-link STA device, or an STA multi-link device.

[0073] The multilink device MLD may implement wireless communication according to an 802.11 series protocol, for example, according to an Extremely High Throughput (EHT) protocol, or according to an 802.11be-based or 802.11be-compatible protocol, to communicate with another device. Of course, the other device may be a multilink device or may not be a multilink device.

[0074] Each logical station can operate on one link, and multiple logical stations are permitted to operate on the same link. The link identifier described below represents one station operating on one link. That is, if there are multiple logical stations on one link, multiple link identifiers are required to represent the logical stations. The link referred to below may also represent a station operating on the link. When data transmission is performed between a multilink device and another multilink device, the multilink device and the other multilink device may first negotiate or communicate with each other regarding the correspondence between the link identifier and the link or the station on the link before communication, or the AP multilink device may indicate the correspondence between the link identifier and the link or the station on the link through a broadcast management frame such as a beacon frame. Therefore, during data transmission, the link identifier is carried without transmitting a large amount of signaling information indicating the link or the station on the link. This reduces signaling overhead and improves transmission efficiency.

[0075] The following uses an example in which the aforementioned one multilink device is an AP multilink device, and the aforementioned another multilink device is a STA multilink device. For example, when an AP multilink device establishes a BSS, a management frame, such as a beacon frame, transmitted from the AP multilink device conveys an element including multiple link identifier information fields. Each link identifier information field can indicate the correspondence between a link identifier and a station operating on the link. Each link identifier information field includes a link identifier, and further includes one or more of a MAC address, an operation class, and a channel number. A link can be identified by one or more of the MAC address, the operation class, and the channel number. As another example, in a multilink association establishment process, the AP multilink device and the STA multilink device negotiate multiple link identifier information fields. In subsequent communication, the AP multilink device or the STA multilink device uses a link identifier to represent a station in the multilink device. The link identifier can further represent one or more attributes of a MAC address, an operation class, and a channel number of the station. The MAC address can alternatively be the association identifier of the associated AP multilink device. Optionally, when multiple stations are operating on a link, the meaning represented by the link identifier (which is a numeric ID) includes not only the channel number and class of operation in which the link resides, but also the identifiers of the stations operating on the link, e.g. the MAC addresses or AIDs of the stations.

[0076] FIG. 1 is a diagram of an application scenario of an embodiment of the present application, taking a wireless local area network as an example. The application scenario includes a first station 101 and a second station 102. The first station 101 can communicate with the second station 102 through multiple links to achieve the effect of improving throughput. The first station may be a multi-link device, and the second station may be a single-link device, a multi-link device, etc. In the scenario, the first station 101 is an AP multi-link device, and the second station 102 is a STA multi-link device or station (e.g., a single-link station). In another scenario, the first station 101 is a STA multi-link device, and the second station 102 is an AP (e.g., a single-link AP) or an AP multi-link device. In yet another scenario, the first station 101 is an AP multi-link device, and the second station 102 is an AP multi-link device or an AP. In yet another scenario, the first station 101 is a STA multi-link device, and the second station 102 is a STA multi-link device or a STA. Of course, additional devices may be included in a wireless local area network, and the number and types of devices shown in Figure 1 are merely examples.

[0077] 2A and 2B show schematic diagrams of the structures of AP multilink device and STA multilink device involved in communication. The 802.11 standard focuses on the 802.11 physical layer (PHY) and media access control (MAC) layer parts of AP multilink device and STA multilink device (such as mobile phone and notebook computer).

[0078] As shown in Fig. 2A, multiple APs included in the AP multilink device are independent from each other in the low MAC layer and the PHY layer, and are also independent from each other in the high MAC layer. Multiple STAs included in the STA multilink device are independent from each other in the low MAC layer and the PHY layer, and are also independent from each other in the high MAC layer.

[0079] As shown in Fig. 2B, multiple APs included in the AP multilink device are independent of each other in the low MAC layer and the PHY layer, and share the high MAC layer. Multiple STAs included in the STA multilink device are independent of each other in the low MAC layer and the PHY layer, and share the high MAC layer.

[0080] Of course, the STA multilink device may use a structure in which the high MAC layers are independent of each other, and the AP multilink device may use a structure in which the high MAC layers are shared. Alternatively, the STA multilink device may use a structure in which the high MAC layers are shared, and the AP multilink device may use a structure in which the high MAC layers are independent of each other. For example, the high MAC layer or the low MAC layer may be implemented by one processor in the chip system of the multilink device, or may be implemented by different processing modules in the chip system.

[0081] For example, the multi-link device in the embodiment of the present application may be a single antenna device or a multi-antenna device. For example, the multi-link device may be a device with two or more antennas. The number of antennas included in the multi-link device is not limited in the embodiment of the present application. For example, FIG. 2C shows an example in which the AP multi-link device is a multi-antenna device and the STA multi-link device is a single-antenna device. In the embodiment of the present application, the multi-link device can enable services of the same access type to be transmitted on different links, or can also enable the same data packet to be transmitted on different links. Alternatively, the multi-link device may not allow services of the same access type to be transmitted on different links, but may allow services of different access types to be transmitted on different links.

[0082] The frequency bands in which the multi-link device operates include, but are not limited to, sub-1 GHz, 2.4 GHz, 5 GHz, 6 GHz, and high frequency 60 GHz. Figures 3A and 3B show two schematic diagrams of communication between a multi-link device and another device over multiple links in a wireless local area network.

[0083] 3A shows a scenario in which an AP multilink device 101 communicates with a STA multilink device 102. The AP multilink device 101 includes an associated AP 101-1 and an associated AP 101-2, the STA multilink device 102 includes an associated STA 102-1 and an associated STA 102-2, and the AP multilink device 101 communicates with the STA multilink device 102 in parallel via link 1 and link 2.

[0084] 3B shows a scenario in which the AP multilink device 101 communicates with the STA multilink device 102, the STA multilink device 103, and the STA 104. The AP multilink device 101 includes the serving AP 101-1 to the serving AP 101-3. The STA multilink device 102 includes two serving STAs, namely, the STA 102-1 and the STA 102-2. The STA multilink device 103 includes two serving STAs, namely, the STA 103-1 and the STA 103-2. The STA 103-3 and the STA 104 are each single-link devices. The AP multilink device can individually communicate with the STA multilink device 102 via link 1 and link 3, communicate with the STA multilink device 103 via link 2 and link 3, and communicate with the STA 104 via link 1. For example, the STA 104 operates in the 2.4 GHz frequency band. The STA multilink device 103 includes STA103-1 and STA103-2, where STA103-1 operates in the 5 GHz frequency band and STA103-2 operates in the 6 GHz frequency band. The STA multilink device 102 includes STA102-1 and STA102-2, where STA102-1 operates in the 2.4 GHz frequency band and STA102-2 operates in the 6 GHz frequency band. The AP 101-1 operating in the 2.4 GHz frequency band in the AP multilink device can perform uplink or downlink data transmission with the STA 104 and STA 102-2 in the STA multilink device 102 via link 1. The AP 101-2 operating in the 5 GHz frequency band in the AP multilink device can perform uplink or downlink data transmission with the STA 103-1 operating in the 5 GHz frequency band in the STA multilink device 103 via link 2. AP 101-3 operating in the 6 GHz frequency band in the AP multilink device 101 can perform uplink or downlink data transmission with STA 102-2 operating in the 6 GHz frequency band in the STA multilink device 102 via link 3, and can also perform uplink or downlink data transmission with STA 103-2 in the STA multilink device via link 3.

[0085] It should be noted that FIG. 3A shows that the AP multilink device only supports two frequency bands, and FIG. 3B shows that the AP multilink device supports three frequency bands (2.4 GHz, 5 GHz, and 6 GHz), each frequency band corresponds to one link, and the AP multilink device 101 uses only an example of working with one or more of link 1, link 2, and link 3 for explanation. On the AP side or STA side, the link here can also be understood as a station working on a link. In practical application, the AP multilink device and the STA multilink device may further support more or less frequency bands. In other words, the AP multilink device and the STA multilink device may work with more or less links. This is not limited in this embodiment of the present application.

[0086] For example, a multi-link device is a device having a wireless communication function. The device may be a system-wide device, or may be a chip, a processing system, etc. mounted on the system-wide device. The device in which the chip or processing system is installed may be controlled by the chip or processing system to implement the method and function in the embodiment of the present application. For example, a multi-link STA in the embodiment of the present application has a wireless transceiver function, supports 802.11 series protocols, and can communicate with a multi-link AP, another multi-link STA, or a single-link device. For example, a multi-link STA is any user communication device in which a user can communicate with an AP and then communicate with a WLAN. For example, a multi-link STA may be a user device that can access a network, such as a tablet computer, a desktop computer, a laptop computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a netbook, a personal digital assistant (PDA), or a mobile phone, or may be an Internet of Things node in the Internet of Things, an in-vehicle communication device in the Internet of Vehicles, etc. Alternatively, the multi-link STA may be a chip or a processing system in the above terminal. The multi-link AP in the embodiment of the present application is a device that provides services to the multi-link STA and may support 802.11 series protocols. For example, the multi-link AP may be a communication entity such as a communication server, a router, a switch, a network bridge, or the multi-link AP may include various forms such as a macro base station, a micro base station, a relay station, etc. Of course, the multi-link AP may also be a chip and a processing system in various forms of devices to implement the methods and functions in the embodiment of the present application. Furthermore, the multi-link device may support high-speed and low-latency transmission.With the continuous evolution of application scenarios of wireless local area networks, multi-link devices may be applied to more scenarios, such as sensor nodes in smart cities (e.g., smart water meters, smart electricity meters, smart air detection nodes), smart devices in smart homes (e.g., smart cameras, projectors, displays, televisions, stereos, refrigerators, washing machines), nodes in the Internet of Things, entertainment terminals (e.g., wearable devices such as AR and VR), smart devices in smart offices (e.g., printers, projectors, etc.), Internet of Vehicles devices in the Internet of Vehicles, and some infrastructures in daily life scenarios (e.g., vending machines, self-service navigation consoles in supermarkets, self-service checkout registers, self-service ordering machines, etc.). The specific forms of the multi-link STA and the multi-link AP are not particularly limited in the embodiments of the present application and are merely examples for the purpose of explanation herein. The 802.11 series protocols may include 802.11be, 802.11ax, 802.11a / b / g / n / ac, etc.

[0087] 2. Multiple Basic Service Set Identifier (BSSID) mode.

[0088] A Multiple BSSID (multiple BSSID) set is a combination of several cooperating APs, all of which use the same operating class, the same channel number, and the same antenna port. In a Multiple BSSID set, there is only one transmitted BSSID AP, and the other APs are non-transmitted BSSID APs. Information about the Multiple BSSID set (i.e., Multiple BSSID elements) is carried in the beacon frame, probe response frame, or neighbor report sent by the transmitted BSSID AP. BSSID of non-transmitted BSSID AP Information about the BSSID of the AP is derived based on the Multiple BSSID elements in the received beacon frame, probe response frame, or neighbor report mentioned above, etc.

[0089] In the Multiple BSSID technology, one physical AP can be virtualized into multiple logical APs to form a Multiple BSSID set. Each virtualized AP manages one BSS, and different logical APs generally have different SSIDs and privileges, such as security mechanisms or transmission opportunities. In a Multiple BSSID set, the BSSID of an AP is configured as a transmitted BSSID, which is called a transmitted AP, and the BSSID of other APs is configured as a non-transmitted BSSID, which is called a non-transmitted AP. In general, multiple APs in a Multiple BSSID set can also be understood as multiple cooperative AP devices obtained by virtualizing one AP device. Only APs whose BSSID is a transmitted BSSID can transmit management frames, such as beacon frames and probe response frames. If a Probe Request frame sent from a STA is addressed to an AP whose BSSID is a non-transmitted BSSID in a Multiple BSSID set, the AP whose BSSID is a transmitted BSSID must help respond to the Probe Response frame. A beacon frame sent by an AP whose BSSID is a transmitted BSSID contains a Multiple BSSID element, and an AP whose BSSID is a non-transmitted BSSID cannot send a beacon frame. Association identifiers (AIDs) assigned by multiple virtual APs to stations managed by the multiple virtual APs share a single space. In other words, the AIDs assigned to stations managed by multiple virtual BSSs cannot be the same.

[0090] In the example, the Multiple BSSID element includes an element ID, a length, a maximum BSSID indicator, and sub-elements, as shown in Table 1. The maximum BSSID indicator indicates that the maximum number of BSSIDs included in the aforementioned Multiple BSSID set is n, and the optional sub-elements include information about each non-transmitted BSSID. The receiving end can calculate the value of each BSSID in the Multiple BSSID set based on the reference BSSID, the maximum BSSID indicator, and the BSSID index. Each BSSID includes 48 bits. The value of the most significant (48-n) bits of each BSSID in the Multiple BSSID set is the same as the value of the most significant (48-n) bits of the reference BSSID, and the value of the least significant n bits of each BSSID in the Multiple BSSID set is obtained by summing the value of the least significant n bits of the reference BSSID and the value of the BSSID index x modulo 2n. The reference BSSID (i.e., the transmitted BSSID) is carried in the BSSID field in the MAC header of the frame (e.g., the beacon frame) that includes the Multiple BSSID element. For specific calculation methods, please refer to the 802.11-2016 standard. [Table 1]

[0091] Table 2 may indicate "optional sub-elements" of Table 1. [Table 2]

[0092] In Table 2, a non-transmitted BSSID profile includes one or more elements of one or more APs or DMG STAs with a non-transmitted BSSID, and a non-transmitted BSSID profile includes, but is not limited to, the following elements: 1. An element related to non-transmitted BSSID capabilities that must be included for each non-transmitted BSSID, along with several other elements in the beacon. 2. An SSID element, and multiple BSSID index elements. 3. An FMS descriptor element that is further included if a Multiple BSSID element is carried in the beacon. 4. None of the following fields: The Timestamp and Beacon Interval fields, DSSS Parameter Set, IBSS Parameter Set, Country, Channel Switch Announcement, Extended Channel Switch Announcement, Wide Bandwidth Channel Switch, Transmit Power Envelope, Supported Operating Classes, IBSS DFS, ERP Information, HT Capabilities, HT Operation, VHT Capabilities, VHT Operation, SIG Beacon Compatibility, Short Beacon Interval, SIG Capabilities, SIG Operation (11ah), and other elements, which are typically transmitted. It has the same element value as the AP corresponding to the BSSID. 5. Optional non-inheritance element. The element is the last element of the non-transmitted BSSID profile. The non-inheritance element contains the ID number and element ID extension number of a set of elements in the non-transmitted BSSID that cannot be inherited from the transmitted BSSID. Note that the specific contents of the elements are omitted here. Specifically, as shown in Table 3, the non-inheritance element contains an element ID, length, element ID extension, element ID list, and element ID extension list. The element ID extension number is present only when the element ID value is 255. [Table 3]

[0093] In the general Multiple BSSID technology, the Multiple BSSID set is virtualized based on only a single-link device. How to apply the Multiple BSSID technology to a multi-link device to provide the function of multiple virtual networks is a technical problem that is being studied by those skilled in the art.

[0094] EMBODIMENT 1 4 shows a method for indicating information based on a multi-link device and multiple BSSIDs according to an embodiment of the present application. This method can be applied between stations, between an access point and a station, and between access points. For ease of explanation, the embodiment of the present application uses the communication between an access point and a station as an example.

[0095] For ease of explanation, an AP in a BSS identified by a transmitted BSSID in a Multiple BSS set is called a transmitting AP (transmitted BSSID AP), and an AP in a BSS identified by a non-transmitted BSSID is called a non-transmitted AP (non-transmitted BSSID AP). In addition, an AP that transmits a management frame conveying information about another AP is called a reporting AP, and another AP in the management frame is called a reported AP. In this embodiment of the present application, an AP multilink device and a device including an AP in a Multiple BSSID set in which an AP in the AP multilink device is located are called a multi-AP multilink device for short. Of course, there may be other names. This is not limited in the present application. The method includes that one AP in the multi-AP multilink device transmits information about all other APs in the multi-AP multilink device to neighboring stations, and a signaling structure of the information about the other APs is designed.

[0096] The method includes, but is not limited to, the following steps.

[0097] Step S101: The access point transmits MLD information to the station.

[0098] The access point is an AP in an AP multi-link device. The station that receives the MLD information may be a station in a multi-link station device or a single-link station. Of course, the MLD information may also be sent from a station, and the station belongs to the MLD. The MLD information may also be received by an access point, and the access point belongs to the MLD or is a single-link access point. The following description will be given using an example of sending MLD information from an access point to a station.

[0099] An AP that transmits MLD information is included in the MLD, which further includes one or more other APs, i.e., the AP that transmits MLD information and other APs that belong to the MLD. Optionally, the AP further belongs to a Multiple BSSID set, which further includes the transmitting AP and one or more non-transmitting APs. Optionally, the other APs in the MLD can alternatively belong to a different Multiple BSSID set.

[0100] In this embodiment of the present application, the AP multilink device and the device including the AP in the Multiple BSSID set in which the AP in the AP multilink device is located are referred to as the Multi-AP multilink device for short. Of course, there may be other names. This is not limited in the present application. In addition, in the embodiment of the present application, the AP that transmits the MLD information may be called the reporting AP, and another AP shown in the MLD information of the Multi-AP multilink device may be called the reported AP. For example, the Multi-AP multilink device includes the MLD to which the reporting AP belongs, and optionally further includes another MLD. The AP in the MLD to which the reporting AP belongs and the AP in the other MLD belong to the Multiple BSSID set.

[0101] The MLD information indicates information about other APs in a multi-AP multi-link setup.

[0102] The alternative AP may include one or more of the following conditions:

[0103] 1. The other APs may include APs that belong to the same AP MLD as the reporting AP.

[0104] 2. If an AP that belongs to the same AP MLD as the reporting AP belongs to a Multiple BSSID set, the other AP will include the other AP in the Multiple BSSID set.

[0105] 3. If the reporting AP belongs to a Multiple BSSID set, the other APs further include other APs that belong to the same Multiple BSSID set as the reporting AP.

[0106] The MLD information may be carried in one or more MLD elements, or optionally the MLD information may additionally be carried in a Multiple BSSID element.

[0107] Additionally, management frames transmitted from a reporting AP may further convey information about the reporting AP, for example, currently 802.11 beacon frames convey information about the reporting AP.

[0108] Based on the MLD information, a station that receives the MLD information can determine information about each respondent AP included in the multi-AP multi-link device, the MLD to which each respondent AP belongs, and which respondent APs and reporting APs belong to the same Multiple BSSID set. Furthermore, the station can establish an association with the appropriate AP or AP MLD.

[0109] Optionally, the MLD information may be carried in management frames, such as beacon frames, association response frames, probe response frames, authentication frames, or neighbor reports.

[0110] The AP multilink device includes n logical APs operating on multiple links. Thus, link identifiers link1, link2, ..., and linkn can be used to represent the n logical APs. The MAC addresses of the APs are different, and n is equal to or greater than 2. The AP multilink device is identified using the MAC address of the MLD. That is, the MAC address is used to identify the AP multilink device management entity. The MAC address of the AP multilink device may be the same as the MAC address of one of the n logical APs included in the multilink AP, or may be different from all the MAC addresses of the n logical APs. For example, the MAC address of the AP multilink device is a common MAC address, and can identify the AP multilink device.

[0111] For example, one or more logical APs in an AP multilink device may belong to one or more multiple Basic Service Set Identifier (BSSID) sets. In an example, the logical APs of an AP multilink device belong to different Multiple BSSID sets. In another example, multiple logical APs of an AP multilink device may belong to the same Multiple BSSID set. For example, when two logical APs in an AP multilink device are operating on one link, the two logical APs may belong to the same Multiple BSSID set.

[0112] For example, as shown in FIG. 5, the MAC address of the AP multilink device is, for example, MLD1. The multilink device includes three logical APs, denoted as AP11, AP21, and AP31. AP11, AP21, and AP31 operate on link 1 (link1), link 2 (link2), and link 3 (link3), respectively. The MAC addresses of AP11, AP21, and AP31 are BSSID-11, BSSID-21, and BSSID-31, respectively (before 802.11ax is established, the BSSID of the BSS established by the AP is the MAC address of the AP, which may change afterwards. For ease of explanation, here we use an example where the MAC address of the AP is the BSSID of the BSS established by the AP.). AP11 is a member of Multiple BSSID set 1, and Multiple BSSID set 1 further includes AP13 with a MAC address of BSSID-13. AP21 is a member of Multiple BSSID set 2, which further includes AP22 with MAC address BSSID-22 and AP23 with MAC address BSSID-23. AP31 is a member of Multiple BSSID set 3, which further includes AP32 with MAC address BSSID-32 and AP33 with MAC address BSSID-33. In the following, an AP multilink device and a device including APs located in the same Multiple BSSID set as the APs in the multilink device are referred to as a multi-AP multilink device for short. For example, AP11, AP21, AP31, AP22, AP32, AP13, AP23, and AP33 form a multi-AP multilink device.

[0113] Step S102: The station receives the MLD information transmitted from the access point AP.

[0114] Specifically, after receiving the MLD information broadcast or unicast by the AP, the station analyzes the content of the MLD information, and the station can obtain the structure of the Multiple BSSIDs configured according to the AP multilink device and information about each reporting AP according to the analyzed content from the MLD information.

[0115] Specifically, the station analyzes the management frame sent from the reporting AP to obtain MLD information about the reporting AP. The MLD information includes one or more MLD elements, and optionally includes a Multiple BSSID element. Specifically, the MLD element includes information about multiple APs in the same MLD. If the reporting AP belongs to a Multiple BSSID set, the MLD information further includes a Multiple BSSID element. The Multiple BSSID element includes information about other APs that belong to the same Multiple BSSID set as the reporting AP, and further includes information about APs in the same AP MLD as the other AP. It can be seen that based on the content analyzed from the MLD information, the station can obtain information about other APs in the multi-AP multi-link device where the reported AP is located.

[0116] The station receives the management frame of the AP and obtains the information of the reporting AP and the information of other APs in the multi-AP multilink device in which the reporting AP is located. In this way, the station can establish an association with the corresponding AP or AP multilink device.

[0117] Optionally, after obtaining information about the Multi-AP Multi-Link device, the station may perform one or more of the following actions:

[0118] (1) Association of a reporting AP with one or more APs in an MLD located on one link. For example, in Fig. 5, after a station receives MLD information sent from AP11 with MAC address BSSID-11 on link 1, the station can select association with AP11 with MAC address BSSID-11 and AP31 with MAC address BSSID-31 in AP multilink device MLD1 where AP11 with MAC address BSSID-11 is located.

[0119] (2) Association of an AP in another MLD other than the MLD to which the reporting AP belongs with another AP on one link. The AP in the other MLD and another AP in the MLD to which the sending AP belongs belong to the same Multiple BSSID set. For example, in FIG. 5, after the station receives the MLD information sent from AP11 with MAC address BSSID-11 on link 1, the station can select association with AP22 with MAC address BSSID-22 and AP32 with MAC address BSSID-32 in the AP multilink device MLD2. AP22 with MAC address BSSID-22 and AP21 with BSSID-21 belong to the same Multiple BSSID set 2. AP32 with MAC address BSSID-32 and AP31 with BSSID-31 belong to Multiple BSSID set 3.

[0120] Optionally, as used herein, associating may refer to exchanging one or more of probe request and probe response frames, authentication request and authentication response frames, and association request or association response frames.

[0121] In the embodiment of the present application, the Multiple BSSID technology is applied to the multilink device to provide the function of multiple virtual networks. In addition, the MLD information can be used to transmit the information of the AP in the multilink device to which the Multiple BSSID technology is applied to the station. The station can select the appropriate AP or AP multilink device for association based on the MLD information, which improves the flexibility of station association.

[0122] EMBODIMENT 2 In this embodiment of the present application, a specific implementation of the signaling structure of MLD information is further described. According to the flexible signaling structure provided in this embodiment, one or more MLD elements and MLD elements included in Multiple BSSID elements are used to describe information about one or more APs in a multi-AP multi-link device, and help stations select appropriate AP or AP MLD for association. The signaling structure of MLD information provided in this embodiment of the present application is simple and flexible.

[0123] First MLD signaling structure: In this embodiment of the present application, the MLD information includes one or more MLD elements. One MLD element is used to indicate one MLD in a multi-AP multilink device. The MLD element includes a common control field, an MLD common information field, and one or more optional sub-elements. Optionally, the MLD common information field includes an MLD address field, and optionally includes fields such as an authentication algorithm field. The MLD address field indicates the address of the MLD indicated by the MLD element, and the address is used to identify one MLD. Optionally, the address of the MLD is the MAC address of the MLD. That is, the MAC address is used to identify the AP multilink device management entity. The MAC address of the AP multilink device may be the same as one of the MAC addresses of the n APs included in the multilink AP, or may be different from all the MAC addresses of the n APs. For example, the MAC address of the AP multilink device is a common MAC address, which can identify the AP multilink device. Optionally, the common control field includes an MLD address present field (or referred to as an MLD address present field or an MLD address present identifier) ​​indicating whether an MLD address field is present in the MLD common information field. Optionally, the common control field further includes an authentication algorithm present field indicating whether an authentication algorithm field is present in the MLD common information field. Optionally, the "presence field" may include 1 bit. A first value indicates that the corresponding field is present, and a second value indicates that the corresponding field is not present. For example, the first value is 1 and the second value is 0. Optionally, if the reporting AP belongs to a Multiple BSSID set, the MLD information further includes a Multiple BSSID element.

[0124] Optionally, an MLD element may contain three types:

[0125] Type 1. Authoritative MLD element. An authoritative MLD element conveys information about all or some other APs that belong to the same MLD as the reporting AP. The authoritative MLD element includes at least one sub-element, and each sub-element conveys information about another AP that belongs to the same MLD as the reporting AP. Of course, the authoritative MLD element may be called a reporting MLD element or may have another name. This is not limited in this embodiment of the present application. For ease of explanation, the MLD element of type 1 is hereinafter referred to as an authoritative MLD element. The common information field of the authoritative MLD element includes an MLD address field.

[0126] Type 2. Virtual MLD element. The virtual MLD element conveys information about all or some APs of another MLD in the multi-AP multi-link device where the reporting AP is located. Since multiple APs included in the MLD to which the reporting AP belongs belong to multiple Multiple BSSID sets, other APs in the multiple Multiple BSSID sets may form another MLD. The virtual MLD element includes at least one sub-element that indicates information about APs included in another MLD. The virtual MLD element can be understood to represent another MLD different from the MLD to which the reporting AP belongs. Of course, the virtual MLD element can have another name as an alternative. This is not limited in this embodiment of the present application. For ease of explanation, the MLD element of type 2 is hereinafter referred to as a virtual MLD element. The common information field of the virtual MLD element includes an MLD address field.

[0127] Type 3. Special MLD element. The MLD element conveys information about a single-link AP in a multi-AP multi-link device where the reporting AP is located. Since multiple APs included in the MLD to which the reporting AP belongs belong to multiple Multiple BSSID sets, other APs in the multiple Multiple BSSID sets may form another MLD. Of course, another AP in the multiple Multiple BSSID sets may not belong to any MLD and is a single-link AP. For example, the common information field of the special MLD element does not include an MLD address field. As another example, the special MLD element may also be considered as a virtual MLD element, and the common information field of the special MLD element also includes an MLD address field. In this case, the MLD address of the MLD element is the MAC address of the single-link AP or the BSSID of the single-link AP.

[0128] In order to distinguish between the three types of MLD elements mentioned above and to help a station determine which MLD elements in the MLD information are for the MLD in which the reporting AP is located, which MLD elements are for another MLD, and which elements are for a single-link AP, in this embodiment of the present application, type information indicating the MLD element type is carried in the MLD element, allowing a station to determine the type of the MLD based on the information and determine the structure and relationships between all MLDs in a multi-AP multi-link device.

[0129] The type information indicating the MLD element type may include, but is not limited to, the following implementations:

[0130] First implementation: The virtual MLD field is carried within an MLD element and indicates whether the MLD element is a virtual MLD element. For example, the virtual MLD field includes one bit that is an indicator bit that indicates whether the MLD element is a virtual MLD element. For example, if the value of the one bit is a first value (e.g., 1), it indicates that the MLD element is a virtual MLD element. If the value of the one bit is a second value (e.g., 0), it indicates that the MLD element is not a virtual MLD element.

[0131] Additionally, a special MLD field may be carried within the MLD element to indicate whether the MLD element is a special MLD element. For example, the special MLD field may include one bit that is an indicator bit indicating whether the MLD element is a special MLD element. For example, if the value of the one bit is a first value (e.g., 1), it indicates that the MLD element is a special MLD element. If the value of the one bit is a second value (e.g., 0), it indicates that the MLD element is not a special MLD element.

[0132] Optionally, if the virtual MLD field indicates that the MLD element is not a virtual MLD element and the special MLD field indicates that the MLD element is not a special MLD element, this implicitly indicates that the MLD element is a proper MLD element.

[0133] For example, if the MLD element is a formal MLD element, the MLD address present field in the common control field is set to a first value, e.g., 1, to indicate the presence of an MLD address field in the MLD common information field. The virtual MLD field is set to a second value, e.g., 0, to indicate the MLD is not a virtual MLD. The special MLD field is set to a second value, e.g., 0, to indicate the MLD is not a special MLD.

[0134] If the MLD element is a virtual MLD element, then the MLD address present field in the common control field is set to a first value, e.g., 1, to indicate the presence of an MLD address field in the MLD common information field. The virtual MLD field is set to a first value, e.g., 1, to indicate that the MLD is a virtual MLD. The special MLD field is set to a second value, e.g., 0, to indicate that the MLD is not a special MLD.

[0135] If the MLD element is a special MLD element, the MLD address present field in the common control field is set to a second value, e.g., 0, to indicate that there is no MLD address field in the MLD common information field or that there is no MLD common information field. The virtual MLD field is set to a second value, e.g., 0, to indicate that the MLD is not a virtual MLD. The special MLD field is set to a first value, e.g., 1, to indicate that the MLD is a special MLD.

[0136] Second implementation. The MLD type indicator field is carried in the MLD element to indicate the type of the MLD element. For example, the MLD type indicator field contains two bits. A first value indicates that the MLD element is a formal MLD element, a second value indicates that the MLD element is a virtual MLD element, and a third value indicates that the MLD element is a special MLD element.

[0137] Of course, it should be noted that the MLD element may include only two types: a formal MLD element and a virtual MLD element. The special MLD element may be considered as a virtual MLD element. In this case, the information indicating the MLD element type may include the virtual MLD field, but not the special MLD field. When the value of the virtual MLD field is a first value, it indicates that the MLD element in which the MLD field is located is a virtual MLD element. When the value of the virtual MLD field is a second value, it indicates that the MLD element in which the MLD field is located is a formal MLD element. For example, the virtual MLD field includes one bit, where 1 indicates that the MLD element is a virtual MLD element and 0 indicates that the MLD element is a formal MLD element. Of course, optionally, the type information in the MLD element may alternatively be a formal MLD field to indicate whether the MLD element is a formal MLD element. For example, when the value of the formal MLD field is a first value, it indicates that the MLD element is a formal MLD element. When the value of the authoritative MLD field is the second value, it indicates that the MLD element is a virtual MLD element. For example, the authoritative MLD field includes one bit, the first value is 1, and the second value is 0.

[0138] 6A is a schematic diagram of the structure of an MLD element. The MLD element includes an element identifier, a length, an element identifier extension field, a common control field, an MLD common information field, and one or more optional sub-elements. The common control field includes a virtual MLD field and a special MLD field. Optionally, the common control field further includes an MLD address presence field. The MLD common information field includes an MLD address field. Optionally, the common control field further includes an authentication algorithm presence field indicating whether an authentication algorithm field is present in the MLD common information field.

[0139] 6B is a schematic diagram of another MLD element structure. The MLD element includes an element identifier, a length, an element identifier extension field, a common control field, an MLD common information field, and one or more optional sub-elements. The common control field includes an indication of the MLD type. Optionally, the MLD common control field further includes an MLD address present field. The MLD common information field includes an MLD address field. Optionally, the common control field further includes an authentication algorithm present field indicating whether an authentication algorithm field is present in the MLD common information field.

[0140] Optionally, an MLD element further contains one or more sub-elements, each of which describes information about an AP in a multi-AP multi-link device. In the case of a sub-element in a formal MLD element, it describes information about another AP that belongs to the same MLD as the reporting AP. In the case of a sub-element in a virtual MLD element, it describes information about an AP in the MLD indicated by the MLD address field. In the case of a sub-element in a special MLD element, it describes information about a single-link AP in multiple BSSID sets including the AP in the AP multi-link device.

[0141] The content of each sub-element includes a link identifier of the AP. Optionally, each sub-element further includes fields related to the AP, such as an SSID field, a timestamp field, a beacon interval field, and AP elements, such as a BSS load element, an EHT capability element, or an EHT operation element.

[0142] For example, for fields and elements carried in sub-elements that describe information about an AP, the inheritance principle is used. In detail: if a field or element carried in a sub-element is the same as a field or element in the reporting AP, the corresponding field and element in the reported AP does not need to be carried in the corresponding sub-element in the reporting AP. If a field or element carried in a sub-element is different from a field or element in the reporting AP, the corresponding field and element in the reported AP needs to be carried in the corresponding sub-element in the reporting AP.

[0143] In another example, the non-inheritance principle is used for fields or elements carried in a sub-element that describes information about an AP. A non-inheritance element is the last element in a sub-element. A non-inheritance element includes a set of element ID numbers and element ID extension numbers that cannot be inherited from the reporting AP. Note that the specific contents of the elements are omitted here. Specifically, as shown in Table 3, a non-inheritance element includes an element ID, a length, an element ID extension, an element ID list, and an element ID extension list. The element ID extension number is only present when the element ID value is 255.

[0144] The link identifier of an AP has a one-to-one correspondence with the operating class in which the AP is located, the channel number, and the BSSID (MAC address) of the AP, and this one-to-one correspondence may be carried by another element, for example the Reduced Neighbor Report (RNR) element described in embodiment 3.

[0145] FIG. 7 is a schematic diagram of a structure of a sub-element according to an embodiment of the present application. A sub-element includes a sub-element ID, a length, and a content field. The content field includes a link identifier of an AP corresponding to the sub-element. There is a correspondence between the link identifier and the operating class where the AP is located, the channel number, and the BSSID (MAC address) of the AP. That is, a station that analyzes the sub-element can learn the operating class, the channel number, and the BSSID of the AP based on the link identifier and the correspondence between the link identifier and the three parameters. The content field further includes field 1, ..., field n, such as an SSID field, a timestamp field, and a beacon interval field. The content field further includes element 1, ..., element n, such as a BSS load element, an EHT capability element, or an EHT operation element. The last element may be a non-inherited element. The non-inherited element includes a set of element ID numbers and element ID extension numbers that cannot be inherited from the reporting AP.

[0146] For example, if the reporting AP belongs to a Multiple BSSID set, the management frame carrying MLD information and transmitted by the reporting AP is in a Multiple BSSID element (only transmitted BSSID APs can transmit management frames) and further carries information indicating non-transmitted BSSID APs that belong to the same Multiple BSSID set as the reporting AP. The information in the Multiple BSSID element and indicating the Non-transmitted BSSID APs in the Multiple BSSID set is called Non-transmitted Profile. If one of the Non-transmitted BSSID APs belongs to an AP MLD, the Non-transmitted Profile further carries an MLD element. The MLD element is a formal MLD element, as shown in Figure 6A, Figure 6B, or Figure 6C. Each sub-element of the MLD element carries information about another AP that belongs to the same AP MLD as the Non-transmitted BSSID AP. The above-mentioned inheritance principle is used for the fields or elements carried in the sub-elements that describe information about another AP. In this case, there are two methods for the target of inheritance slowdown. Method 1. As before, the inherited object remains a reporting AP. Method 2. The inherited object is changed to a Non-transmitted BSSID AP.

[0147] The first signaling structure of the MLD information is applicable to multiple multi-AP multi-link devices.

[0148] Solution 1: Structure of Multi-AP Multilink Device. The transmitted BSSID APs in multiple Multiple BSSID sets are not from the same AP Multilink device. That is, the same AP Multilink device may contain one transmitted BSSID AP belonging to a Multiple BSSID set and one non-transmitted BSSID AP belonging to another Multiple BSSID set. For example, AP1 in an AP Multilink device (MLD1) is a transmitted BSSID AP in Multiple BSSID set 1, and AP2 in an AP Multilink device (MLD1) is a non-transmitted BSSID AP in Multiple BSSID set 2. In this case, the network configured by the Multiple BSSIDs of the Multilink device is more flexible and more suitable for the service requirements of different stations.

[0149] According to the above first signaling structure and the multi-AP multi-link device of Solution 1, this embodiment of the present application provides a signaling information exchange method for a multi-AP multi-link device. For example, as shown in FIG. 10A, the method includes the following steps:

[0150] Step S201: An access point sends a management frame to a station. The management frame carries MLD information. The MLD information includes one official MLD element and at least one virtual MLD element, optionally one Multiple BSSID element, and optionally a special MLD element.

[0151] The access point belongs to the access point MLD. For example, the access point is an AP in an AP multi-link device, and the access point is called a reporting AP. The station that receives the management frame may be a station in a multi-link station device, or may be a single-link station.

[0152] The management frame may be, for example, a beacon frame, an association response frame, a probe response frame, an authentication frame, or a neighbor report. The MLD information conveys information about another AP (called a reported AP) that shares the device with the reporting AP. The reported AP may include at least one of the following conditions:

[0153] 1. A reported AP may include another AP that belongs to the same AP MLD as the reporting AP.

[0154] 2. If another AP that belongs to the same AP MLD as the reporting AP belongs to the Multiple BSSID set, the reporting AP further includes the other AP in the Multiple BSSID set.

[0155] 3. If the reporting AP belongs to a Multiple BSSID set, the reporting AP further includes another AP that belongs to the same Multiple BSSID set as the reporting AP.

[0156] In the first signaling structure of the MLD information, the MLD information includes a formal MLD element and a virtual MLD element, and optionally further includes a special MLD element. The formal MLD element includes information about one or more other APs in the first MLD to which the reporting AP belongs. That is, the formal MLD element includes sub-elements, and one sub-element carries information about another AP in the first MLD. Optionally, if the reporting AP belongs to the first Multiple BSSID set, the MLD information further includes a Multiple BSSID element. Optionally, the Multiple BSSID element includes information about one or more or all other APs in the first Multiple BSSID set to which the reporting AP belongs. If the other AP in the first MLD belongs to a second Multiple BSSID set and the AP included in the second Multiple BSSID set belongs to a second MLD, the MLD information further includes one virtual MLD element. The virtual MLD element includes information about the AP in the second MLD. For example, the virtual MLD element includes sub-elements, and one sub-element carries information about one AP in the second MLD. If another AP in the first MLD belongs to the third Multiple BSSID set, and the AP included in the third Multiple BSSID set does not belong to any MLD, the MLD information includes a special MLD element or a virtual MLD element. The MLD element includes sub-elements carrying information about APs that do not belong to any MLD. Furthermore, if the non-transmitting AP in the first Multiple BSSID set further belongs to the third MLD, the Multiple BSSID element further includes a fourth MLD element. The fourth MLD element may be a formal MLD element carrying information about another AP in the third MLD. In other words, the MLD information may be carried in one or more MLD elements, or optionally, information about the reporting AP may be additionally carried in the Multiple BSSID element.

[0157] Additionally, management frames transmitted from a reporting AP may further convey information about the reporting AP, for example, currently 802.11 beacon frames convey information about the reporting AP.

[0158] Note that the MLD information may also be called MLD multiple BSSID information, etc. Of course, the MLD information may alternatively have another name, which is not specifically limited in this embodiment of the present application.

[0159] Step S202: The station receives the management frame transmitted from the access point.

[0160] Specifically, the station analyzes the management frame sent from the reporting AP to obtain MLD information about the reporting AP. The MLD information includes one or more MLD elements, and optionally includes a Multiple BSSID element. Optionally, if the reporting AP belongs to a first Multiple BSSID set, the MLD information further includes a Multiple BSSID element. The Multiple BSSID element includes information about another AP that belongs to the same first Multiple BSSID set as the reporting AP, and optionally further includes information about an AP in the same third AP MLD as the other AP.

[0161] Optionally, the method can further include step S203. According to the content parsed from the MLD information, the station can know the structure of the multiple BSSIDs set according to the AP multilink device and information about each reporting AP.

[0162] The station receives the management frame and, based on the management frame, learns information about the reporting AP and other APs that share devices with the reporting AP. In this way, the station can select a corresponding AP or AP multilink device with which to establish an association.

[0163] This embodiment of the present application provides signaling information. The signaling information conveys information about each AP in a multi-link device to which the Multiple BSSID technology is applied. The signaling structure is simple, and can convey information about all other APs of the multi-AP multi-link device, for example. In addition, the signal structure provided in the embodiment of the present application is applicable to a multi-AP multi-link device including multiple multi-link devices to which the Multiple BSSID technology is applied. The signal structure is very flexible and simple.

[0164] The following describes the architecture of the multi-AP multilink device in solution 1. Figure 8A is a schematic diagram of the structure of the multi-AP multilink device in solution 1. An AP whose MAC address identifier ends with x is a transmitted BSSID AP, and an AP whose MAC address identifier ends with y or z is a non-transmitted BSSID AP. For example, the transmitted BSSID AP in Multiple BSSID set 1 is AP1x whose MAC address identifier is BSSID-1x, and the non-transmitted BSSID AP in Multiple BSSID set 1 is AP1y whose MAC address identifier is BSSID-1y. The transmitted BSSID AP in Multiple BSSID set 2 is AP2x whose MAC address identifier is BSSID-2x, and the non-transmitted BSSID AP in Multiple BSSID set 2 includes AP2y whose address identifier is BSSID-2y and AP2z whose MAC address identifier is BSSID-2z. The transmitted BSSID AP of Multiple BSSID set 3 is AP3x with MAC address identifier BSSID-3x, and the non-transmitted BSSID AP of Multiple BSSID set 3 includes AP3y with MAC address identifier BSSID-3y and AP3z with MAC address identifier BSSID-3z. From Fig. 8a, it can be seen that the transmitted BSSID APs (i.e., transmitting APs) from different Multiple BSSID sets are distributed in different AP multilink devices. For example, AP1x with MAC address BSSID-1x and AP2x with MAC address BSSID-2x are in AP multilink device MLD1 and AP multilink device MLD2, respectively.

[0165] For ease of understanding, this embodiment of the present application uses FIG. 8a as an example to describe the signaling structure of MLD information in some cases.

[0166] Example 1: AP1x in AP MLD1 shown in Fig. 8a transmits a management frame, such as a beacon frame or a probe response frame. The transmission method may be broadcast or unicast. Therefore, AP1x is a reporting AP. As shown in Fig. 9a, the MLD information carried in the management frame includes three MLD elements. The first MLD element is a formal MLD element, the common information field includes the address of AP MLD1, the formal MLD element carries two sub-elements, the first sub-element carries information about AP2y, and the second sub-element carries information about AP3x. The second MLD element is a virtual MLD element, the common information field includes the address of AP MLD1, the virtual MLD element carries two sub-elements, the second sub-element carries information about AP2x, and the second sub-element carries information about AP3y. The third MLD element is a special MLD element, the common information field does not exist or the MLD address field does not exist. The special MLD element carries one sub-element, and the sub-element carries information about AP3z. In addition, since the reporting AP1x belongs to Multiple BSSID set 1, the MLD information of the management frame needs to further carry a Multiple BSSID element. The element carries a non-transmitted BSSID profile, and the non-transmitted BSSID profile is information about AP1y. In addition, since AP1y belongs to AP MLD3, the non-transmitted BSSID profile further carries a fourth MLD element. The fourth MLD element may be a formal MLD element, and the formal MLD element means that AP2z and AP1y belong to the same MLD. The common information field of the MLD element includes the address of AP MLD3. The MLD element carries one sub-element, and the sub-element carries information about AP2z. Correspondingly, the station receiving the management frame can know the information of each AP in the multi-AP multilink device and the relationship between the APs based on the three MLD elements and the Multiple BSSID element carried in the MLD information. For example, a station may learn based on the first MLD element that AP1x, AP2y, and AP3x all belong to MLD1.The station can learn, based on the second MLD element, that AP2x and AP3y both belong to MLD2. The station can learn, based on the third MLD element, that AP3z is a single-link device. The station can learn, based on the multiple MLD element, that AP1y and AP1x belong to one multiple BSSID set. The station can learn, based on the MLD element contained in the multiple BSSID element, that AP1y and AP2z both belong to MLD3.

[0167] Example 2: AP1x in AP MLD1 shown in FIG. 8a transmits a management frame, such as a beacon frame or a probe response frame. The transmission method may be broadcast or unicast. As shown in FIG. 9b, the management frame carries MLD information. The MLD information includes three MLD elements. The first MLD element is a formal MLD element, the common information field of the first MLD element includes the address of AP MLD1, and carries two sub-elements, the first sub-element carries information about AP2y, and the second sub-element carries information about AP3x. The second MLD element is a virtual MLD element, the common information field of the second MLD element includes the address of AP MLD2, and carries two sub-elements, the first sub-element carries information about AP2x, and the second sub-element carries information about AP3y. The third MLD element is a virtual MLD element, the common information field of the third MLD element includes the address of AP3z, and carries one sub-element, and the sub-element carries information about AP3z. Since the reporting AP1x belongs to the Multiple BSSID set, the MLD information of the management frame needs to further carry a Multiple BSSID element. The element carries the non-transmitted BSSID profile, and the non-transmitted BSSID profile is information about AP1y. Furthermore, since AP1y belongs to AP MLD3, the non-transmitted BSSID profile further carries a formal MLD element. The common information field of the formal MLD element contains the address of AP MLD3 and carries one sub-element, and the sub-element carries information about AP2z. Note that there is no special MLD element in this example. Correspondingly, the station receiving the management frame can know the information of each AP in the multi-AP multi-link device and the relationship between the APs based on the three MLD elements and the Multiple BSSID element carried in the MLD information. For example, the station can learn that AP1x, AP2y, and AP3x all belong to MLD1 based on the first MLD element. The station can learn based on the second MLD element that AP2x and AP3y both belong to MLD2.The station can learn, based on the third MLD element, that AP3z in the third MLD element is a single-link device. The station can learn, based on the multiple MLD element, that AP1y and AP1x belong to one multiple BSSID set. The station can learn, based on the MLD element contained in the multiple BSSID element, that AP1y and AP2z both belong to MLD3.

[0168] Example 3: AP2x in AP MLD2 shown in FIG. 8a transmits a management frame such as a beacon frame or a probe response frame. The transmission method may be broadcast or unicast. As shown in FIG. 9c, the management frame carries MLD information. The MLD information carries two MLD elements. One MLD element is a formal MLD element, the common information field of the formal MLD element contains the address of AP MLD2, and one sub-element is carried, which carries information about AP3y. The other MLD element is a special MLD element, the common information field does not exist, and one sub-element is carried, which carries information about AP3z. Because the reporting AP2x belongs to a Multiple BSSID set, the MLD information of the management frame needs to further carry a Multiple BSSID element. The element carries two non-transmitted BSSID profiles. One non-transmitted BSSID profile is information about AP2y. Furthermore, since AP2y belongs to AP MLD1, the non-transmitted BSSID profile of AP2y further carries an official MLD element. The common information field of the official MLD element contains the address of AP MLD1. The official MLD element carries two sub-elements. One sub-element carries information about AP1x, and the other sub-element carries information about AP3x. The other non-transmitted BSSID profile is information about AP2z. Furthermore, since AP2z belongs to AP MLD3, the non-transmitted BSSID profile of AP2z further carries an official MLD element. The common information field of the official MLD element contains the address of AP MLD3 and carries one sub-element, and the sub-element carries information about AP1y. Correspondingly, the station receiving the management frame can know the information of each AP in the multi-AP multi-link device and the relationship between the APs based on the two MLD elements and the Multiple BSSID element carried in the MLD information. For example, a station may learn based on MLD factor 1 that AP2x and AP3y both belong to MLD2.The station may learn, based on the MLD element 2, that AP3z is a single-link device. The station may learn, based on the multiple MLD elements, that AP2x, AP2y, and AP2z all belong to one multiple BSSID set. Based on the MLD element carried in the non-transmitted BSSID profile of AP2y in the Multiple BSSID element, it may be determined that AP1x, AP2y, and AP3x belong to MLD1. Based on the MLD element carried in the non-transmitted BSSID profile of AP2z in the Multiple BSSID element, it may be determined that AP1y and AP2z belong to MLD3.

[0169] It should be noted that the positions of the MLD element and the Multiple BSSID element are merely examples, and are not limited to the order shown in FIGS. 9A to 9C in the embodiments of the present application. It can be understood that each MLD element includes a type identifier, and therefore a station can determine the type of the MLD element based on the type identifier. Therefore, the positions of the multiple MLD elements may also be arbitrary. Furthermore, a station can also identify that an element is a Multiple BSSID element based on an element ID in the Multiple BSSID element. Therefore, the Multiple BSSID element can also be placed before the MLD element.

[0170] Additionally, optionally, the management frame transmitted by the reporting AP may need to further convey a link identifier of the reporting AP, e.g., a common information field carried in the EHT operation element or in the MLD element, e.g., the common information field carried in the MLD element shown in FIG. 6A or FIG. 6B.

[0171] Optionally, the information about all APs (including the reporting AP and the reported AP) includes one or more of, but is not limited to, AP capability information, AP operation information, AP link identifier, etc. Optionally, the information about the AP may further include the AP's MAC address (BSSID), including other fields or elements carried in beacons of current 802.11 protocols (e.g., 802.11-2016 protocols), such as a timestamp field, a beacon interval field, an SSID element, and a BSS load element. The AP capability information includes an HT capability element, a VHT capability element, an HE capability element, and an EHT capability element. The AP operation information includes an HT operation element, a VHT operation element, an HE operation element, and an EHT operation element. If the AP is a 6 GHz AP, the AP capability element does not include an HT capability element or a VHT capability element, and includes an HE capability element and an EHT capability element. The AP operation element does not include an HT operation element or a VHT operation element, and includes an HE operation element and an EHT operation element.

[0172] The information about the reporting AP is carried in a management frame, such as a beacon frame or a probe response frame, transmitted from the AP. The information about the APs sharing the device with the reporting AP is carried in an MLD element or a Multiple BSSID element in the management frame transmitted from the AP. Device sharing means that the AP and the reporting AP are in one multi-AP multi-link device. Of course, the first signaling structure of the MLD information provided in this embodiment of the present application may be further applied to another multi-AP multi-link device structure. FIG. 8A is merely an example. For example, the signaling information provided in this embodiment of the present application may be further applied to a multi-AP multi-link device structure of solution 2, such as the multi-AP multi-link device structure shown in FIG. 8B. Note that in FIG. 8Aa and FIG. 8B, only three links are described as an example. The signaling information provided in this embodiment of the present application may be further applied to a multi-AP multi-link device structure having more links.

[0173] In another possible implementation, the MLD information may further include only one MLD element. Optionally, if the reporting AP belongs to a first Multiple BSSID set, the MLD information further includes a Multiple BSSID element carrying information about another AP in the first Multiple BSSID set. If the other AP belongs to a second MLD, the Multiple BSSID element further includes information about another AP in the second MLD. This MLD element carries other APs in the multi-AP multilink device, except for the reported AP carried in the Multiple BSSID element. That is, in the multi-AP multilink device where the reporting AP is located, all other reported APs not indicated in the Multiple BSSID element are carried in one MLD element, and the MLD element carries multiple sub-elements, and one sub-element carries information about one of the other reported APs. Specifically, the common information field in the MLD element carries one or more combinations of MLD identifier and MLD address. The number of combinations is indicated in the common control field. In addition to the link identifier of the reporting AP and the information about the AP, the sub-element indicating each reported AP must further carry the MLD identifier of the MLD in which the AP is located. Optionally, the identifier of the MLD in which the reported AP is located is the same as the MLD identifier corresponding to the reporting AP in the RNR. For details of the RNR carrying the MLD identifier of the MLD in which the reported AP is located, please refer to the last embodiment. Optionally, if the reported AP is a single-link AP, the MLD address corresponding to the reported AP in the common field is the MAC address (BSSID) of the single-link AP. In this implementation, there is no virtual MLD element, special MLD element, etc.

[0174] Example 4: AP1x in AP MLD1 shown in FIG. 8a transmits a management frame such as a beacon frame or a probe response frame. The transmission method may be broadcast or unicast. The management frame carries MLD information. The MLD information includes one MLD element. The common information field of the MLD element includes three combinations of MLD identifiers and MLD addresses, which are combination 1 of MLD1 identifier and MLD1 address, combination 2 of MLD2 identifier and MLD2 address, and combination 3 of AP3z identifier and AP3z address. In addition, the MLD element carries five sub-elements, which respectively carry information on AP2y, AP3x, AP2x, AP3y, and AP3z. Because the reporting AP1x belongs to a Multiple BSSID set, the MLD information of the management frame needs to further carry a Multiple BSSID element. The element carries a non-transmitted BSSID profile, and the non-transmitted BSSID profile is information on AP1y. In addition, since AP1y belongs to AP MLD3, the non-transmitted BSSID profile further carries an MLD element. The common information field of the MLD element contains the address of AP MLD3 and carries one sub-element, which carries information about AP2z. Correspondingly, a station receiving a management frame can know information about each AP in a multi-AP multi-link device and the relationship between the APs based on one MLD element and one Multiple BSSID element carried in the MLD information. For example, the station can know that AP1x, AP2y, and AP3x all belong to MLD1, AP2x and AP3y all belong to MLD2, and AP3z in the third MLD element is a single-link device based on the combination in the MLD element and the MLD identifier in the sub-element. The station can know that AP1y and AP1x belong to one Multiple BSSID set based on the Multiple BSSID element, and the station can know that AP1y and AP2z both belong to MLD3 based on the MLD element contained in the Multiple BSSID element.

[0175] The following describes the structure of the multi-AP multi-link device of Solution 2.

[0176] Solution 2:

[0177] The transmitted BSSID APs in multiple Multiple BSSID sets belong to the same AP Multilink device. That is, if one or more APs in an AP Multilink device belong to a Multiple BSSID set, the transmitted BSSID APs in the Multiple BSSID set all belong to one AP Multilink device. For example, the transmitted BSSID AP1 in Multiple BSSID set 1 and the transmitted BSSID AP2 in Multiple BSSID set 2 belong to two different APs in the AP Multilink device MLD1. In this case, the Multiple BSSID network built based on the AP Multilink device is simpler and has less signaling MLD information overhead.

[0178] Based on the structure of the multi-AP multi-link device in Solution 2, this embodiment of the present application provides a second signaling structure of MLD information.

[0179] In the second signaling structure of the MLD information, the MLD information includes one MLD element. Optionally, if the reporting AP belongs to the first Multiple BSSID set, the MLD information further includes a Multiple BSSID element. Optionally, the Multiple BSSID element includes information about one or more or all other APs (non-transmitted BSSID APs) in the first Multiple BSSID set to which the reporting AP belongs. The MLD element includes information about one or more other APs in the first MLD to which the reporting AP belongs. That is, the MLD element includes sub-elements, and one sub-element carries information about another AP in the first MLD. For another AP in the first MLD, the other AP in the first MLD also becomes a transmitting AP in the structure of solution 2. If the other AP in the first MLD further belongs to one or more second Multiple BSSID sets, the sub-element of the other AP in the first MLD further includes a Multiple BSSID element, indicating information about the other AP (non-transmitted BSSID AP) in the second Multiple BSSID set.

[0180] In the second signaling structure of the MLD information, the MLD information also includes an MLD element, and optionally further includes a multiple BSSID element. Compared with the first signaling structure of the MLD information, the second signaling structure of the MLD information may not include various types of MLD elements, and the types are not distinguished. The MLD element includes a common control field, an MLD common information field, and optionally one or more sub-elements. One sub-element indicates information about a reportee AP. For example, the structure of the MLD element in the second signaling structure of the MLD information is shown in FIG. 6C, and the signaling structure of one sub-element is shown in FIG. 7.

[0181] According to the above second signaling structure, this embodiment of the present application provides another signaling information exchange method for multi-AP multi-link devices. For example, as shown in Figure 10B, the method includes the following steps:

[0182] Step S301: An access point sends a management frame to a station. The management frame carries MLD information. The MLD information includes an MLD element. Optionally, a sub-element of the MLD element includes a Multiple BSSID element.

[0183] The access point belongs to the access point MLD. For example, the access point is an AP in an AP multi-link device, and the access point is called a reporting AP. The station that receives the management frame may be a station in a multi-link station device, or may be a single-link station.

[0184] A management frame may be, for example, a beacon frame, an association response frame, a probe response frame, an authentication frame, or a neighbor report. The MLD information conveys information about other APs (called reported APs) that share the device (the multi-AP multi-link device in which the reporting AP is located) with the reporting AP. The reported APs are:

[0185] 1. A recipient AP includes another AP that belongs to the same AP MLD as the reporting AP.

[0186] 2. If another AP that belongs to the same AP MLD as the reporting AP belongs to the Multiple BSSID set, the reported AP also includes the APs in the Multiple BSSID set.

[0187] 3. If the reporting AP belongs to a Multiple BSSID set, the reporting AP further includes another AP that belongs to the same Multiple BSSID set as the reporting AP.

[0188] The MLD information may use the MLD element. If the reported AP described by the subelement in the MLD element belongs to a Multiple BSSID set, the subelement further contains a Multiple BSSID element, which indicates information about other APs (non-transmitted BSSID APs) in the same Multiple BSSID set where the reported AP is located. For the signaling design and structure of the MLD element, see the description in the previous paragraph. For the signaling design and structure of the Multiple BSSID element, see the description in the previous paragraph.

[0189] Additionally, management frames transmitted from a reporting AP may further convey information about the reporting AP, for example, currently 802.11 beacon frames convey information about the reporting AP.

[0190] Note that the MLD information may also be called MLD multiple BSSID information, etc. Of course, the MLD information may alternatively have another name, which is not specifically limited in this embodiment of the present application.

[0191] Step S302: The station receives a management frame transmitted from the access point.

[0192] Specifically, the station analyzes the management frame transmitted from the reporting AP to obtain MLD information about the reporting AP. The MLD information includes an MLD element. Optionally, a sub-element of the MLD element includes a Multiple BSSID element. Specifically, if the reporting AP belongs to a Multiple BSSID set, the MLD information further includes a Multiple BSSID element. The Multiple BSSID element includes information about another AP that belongs to the same Multiple BSSID set as the reporting AP. If the AP that belongs to the same MLD as the reporting AP further belongs to a transmitting AP in a second Multiple BSSID set, the sub-element of the transmitting AP in the MLD element further includes a Multiple BSSID element to carry information about a non-transmitting AP in the second Multiple BSSID set.

[0193] Optionally, the method can further include step S303. According to the content parsed from the MLD information, the station can know the structure of the multiple BSSIDs set according to the AP multilink device and information about each reporting AP.

[0194] The station receives the management frame of the AP, and based on the management frame, learns information about the reporting AP and other APs that share devices with the reporting AP. In this way, the station can select a corresponding AP or AP multilink device to establish an association with.

[0195] The following describes the architecture of the multi-AP multilink device of solution 2. Figure 8B is a schematic diagram of the structure of the multi-AP multilink device in solution 2. The AP whose MAC address identifier ends with x is a transmitted BSSID AP, and the AP whose MAC address identifier ends with y or z is a non-transmitted BSSID AP. For example, the transmitted BSSID AP of Multiple BSSID set 1 is AP1x whose MAC address identifier is BSSID-1x, and the non-transmitted BSSID AP of Multiple BSSID set 1 is AP1y whose MAC address identifier is BSSID-1y. The transmitted BSSID AP in Multiple BSSID set 2 is AP2x whose MAC address identifier is BSSID-2x, and the non-transmitted BSSID AP in Multiple BSSID set 2 includes AP2y whose MAC address identifier is BSSID-2y and AP2z whose MAC address identifier is BSSID-2z. The transmitted BSSID AP in Multiple BSSID set 3 is AP3x with a MAC address identifier of BSSID-3x. From Fig. 8B, it can be seen that the transmitted BSSID APs (ie, transmitting APs) from different Multiple BSSID sets are all in the AP multilink device MLD1.

[0196] For ease of understanding, this embodiment of the present application uses FIG. 8B as an example to describe the signaling structure of MLD information in some cases.

[0197] Example 1: AP1x in AP MLD1 shown in FIG. 8B transmits a management frame, such as a beacon frame or a probe response frame. The transmission method may be broadcast or unicast. For example, as shown in FIG. 9D, the management frame carries an MLD element. The MLD common information field contains the address of AP MLD1, and carries two sub-elements, the first sub-element carries information about AP2y, and the second sub-element carries information about AP3x. Because AP2x carried in the first sub-element belongs to a Multiple BSSID set, the sub-element needs to additionally transmit one Multiple BSSID element 2. This element carries two non-transmitted BSSID profiles, which respectively describe information about AP2y and AP2z. Because the reporting AP1x belongs to a Multiple BSSID set, the MLD information of the management frame needs to further carry Multiple BSSID element 1. The element carries the non-transmitted BSSID profile, and the non-transmitted BSSID profile is information about AP1y. Correspondingly, a station receiving the management frame can learn information about each AP in the multi-AP multi-link device and the relationship between the APs based on the MLD information. For example, a station can learn that AP1x, AP2x, and AP3x all belong to MLD1 based on the MLD element. A station can learn that AP2x, AP2y, and AP2z all belong to one multiple BSSID set 2 based on multiple MLD element 2 in the first subelement. A station can learn that AP1x and AP1y belong to multiple BSSID set 1 based on multiple MLD element 1.

[0198] It should be noted that the positions of the MLD element and the Multiple BSSID element are merely examples, and are not limited to the order shown in FIG. 9D in the embodiment of the present application. It can be understood that each MLD element includes a type identifier, and therefore the station can determine the type of the MLD element based on the type identifier. Therefore, the positions of the multiple MLD elements may also be arbitrary. Furthermore, the station can also identify that the element is a Multiple BSSID element based on the element ID in the Multiple BSSID element. Therefore, the Multiple BSSID element can also be placed before the MLD element.

[0199] In this embodiment, for the flexible structure of the multi-AP multi-link device, a signaling structure of MLD information indicating the flexible structure of the multi-AP multi-link device is designed. The MLD information describes information about one or more APs in the multi-AP multi-link device using one or more MLD elements and MLD elements included in the Multiple BSSID element. The signaling structure of the MLD information is simple and flexible, and can flexibly and completely indicate information about APs included in the structure of the multi-AP multi-link device. Furthermore, the access point indicates a Multiple BSSID set structure based on the AP multi-link device to the station based on the MLD information. The station can obtain information about each AP of the multi-AP multi-link device based on the MLD information, and help the station select a suitable AP or AP MLD for association. This improves the flexibility of the selection of APs by the station for association.

[0200] EMBODIMENT 3 The embodiment of the present application provides yet another signaling information exchange method (including a transmission method and a reception method) for a multi-AP multilink device. In this embodiment, in a multi-AP multilink device where a reporting AP is located, an RNR element, an MLD element, and a Multiple BSSID element are used in combination to prevent the reporting AP from broadcasting information about one or more or all APs. This reduces signaling overhead. In addition, in order to prevent parameters such as an AP's operation class, channel number, and BSSID from being repeated in subsequent multilink operations, an AP's link identifier is added to the RNR element and the Multiple BSSID element. There is a correspondence between the AP's link identifier and parameters such as an AP's operation class, channel number, and BSSID. In subsequent transmissions or communications, the AP's operation class, channel number, BSSID, and other parameters do not need to be carried. This reduces signaling overhead. Also, because the operating class and channel number of the non-transmitted BSSIDs in the Multiple BSSID element are the same as the operating class and channel number of the transmitted BSSIDs in the Multiple BSSID element, the two parameters, operating class and channel number, do not appear in the non-transmitted BSSID profile of the Multiple BSSID element, which reduces signaling overhead.

[0201] This embodiment of the present application provides another information exchange method for multi-AP multi-link devices. As shown in Figure 11, the method further includes the following steps:

[0202] Step S401: An access point transmits a management frame, which includes a reduced neighbor report element (RNR) element and a Multiple BSSID element, and optionally includes an MLD element.

[0203] The access point belongs to the access point MLD. For example, the access point is an AP in an AP multi-link device, and the management frame is transmitted from the access point, and the access point is called a reporting AP. The station receiving the management frame may be a station in a multi-link station device or a single-link station. The reporting AP belongs to a Multiple BSSID set, and the reporting AP is a transmitting AP in the Multiple BSSID set, and the Multiple BSSID set further includes a non-transmitting AP. Therefore, the management frame includes a Multiple BSSID element. The Multiple BSSID element includes a non-transmitted BSSID profile of the non-transmitting AP to indicate the non-transmitting AP.

[0204] Optionally, the management frame is a beacon frame, an association response frame, a probe response frame, an authentication frame, or a neighbor report.

[0205] The RNR, MLD, and Multiple BSSID elements convey information about other APs (called reported APs) that share the device with the reporting AP.

[0206] Step S402: The station receives a management frame transmitted from the access point.

[0207] Specifically, the station analyzes the management frame sent from the reporting AP to obtain the RNR element and the Multiple BSSID element, and optionally obtains the MLD element to obtain the Multiple BSSID set structure based on the AP multilink device.

[0208] Optionally, the method further includes step S403. Based on the management frame, determine a Multiple BSSID set structure based on the AP multilink device and information about each AP. Furthermore, the station can further select an appropriate AP or AP MLD for association based on the structure and the information about each AP.

[0209] Based on this solution, the station can obtain information about the reporting AP and other APs that share the device with the reporting AP based on the management frame. In this way, the station can select an appropriate AP or AP multilink device to establish an association with.

[0210] The RNR, MLD, and Multiple BSSID elements convey information about other APs (called reported APs) that share the device with the reporting AP.

[0211] The respondent AP is:

[0212] 1. A recipient AP includes another AP that belongs to the same AP MLD as the reporting AP.

[0213] 2. If another AP that belongs to the same AP MLD as the reporting AP belongs to the Multiple BSSID set, the reported AP also includes the APs in the Multiple BSSID set.

[0214] 3. If the reporting AP belongs to a Multiple BSSID set, the reporting AP further includes another AP that belongs to the same Multiple BSSID set as the reporting AP.

[0215] Additionally, management frames transmitted from a reporting AP may further convey information about the reporting AP, for example, currently 802.11 beacon frames convey information about the reporting AP.

[0216] In addition, in order to avoid repetition of parameters such as the AP's operating class, channel number, and BSSID in subsequent multi-link operations, in the embodiment of the present application, the AP's link identifier is added to the RNR element and the Multiple BSSID element so that there is a one-to-one correspondence between the AP's operating class, channel number, BSSID, and other parameters.

[0217] The following describes in detail the aforementioned Multiple BSSID set structure based on AP multilink device, the information about APs in the structure, and the method of indicating the relationship between APs, with reference to the RNR element, the MLD element, and the Multiple BSSID element.

[0218] Part 1: RNR elements

[0219] First, the RNR element includes simplified information about other APs that belong to the same MLD as the reporting AP and information about other APs that belong to the same Multiple BSSID set as the reporting AP. Optionally, simplified information about non-transmitting APs that belong to the same Multiple BSSID set as the reporting AP is not carried. For example, take the multiple BSSID set structure of the AP multilink device shown in FIG. 8A as an example. The RNR element sent by the reporting AP conveys simplified information about AP2y, AP3x, AP2x, AP3y, AP3z, and AP2z, and does not carry simplified information about AP1y. Since both AP1x and AP1y belong to one Multiple BSSID, AP1y is a Non-transmitted BSSID AP, which is carried in the Multiple BSSID element sent by AP1x. AP1x acts as a reporting AP, and information about AP1x is carried in the management frame. In this case, there is no need to include in the RNR element the simplified information about the non-transmitted BSSID APs in the Multiple BSSID set in which the reporting AP is located, which reduces the signaling overhead caused by transmitting repeated signaling.

[0220] Secondly, in order to avoid the repetition of parameter information of each AP, such as operating class, channel number, BSSID, etc., in another multi-link operation interaction process, the RNR element can further convey the link identifier of each reported AP, and indicate the correspondence between the link identifier of the reported AP and three parameters, such as the operating class, channel number, and BSSID of the reported AP.

[0221] Additionally, optionally, the RNR element further conveys information indicating the relationship between the reported AP and the reporting AP.

[0222] For example, the RNR element may further include signaling information indicating one or more of the following three relationships: 1. Whether the reported AP and the reporting AP are of the same MLD; 2. Whether the reported AP and other APs in the MLD where the reporting AP is located are from the same Multiple BSSID; 3. Whether the reported AP and the reporting AP are in the same MLD, or whether the reported AP belongs to the same Multiple BSSID set as a member of the MLD to which the reporting AP belongs.

[0223] For example, the above three relationships are indicated separately using one bit. In an example, information is conveyed in the BSS parameter field of the TBTT information field of the RNR element to indicate one or more of the above relationships. For example, the co-MLD field is conveyed in the BSS parameter field. The co-MLD field indicates whether the reported AP and the reporting AP are in the same MLD, or whether the member APs of the MLD to which the reported AP and the reporting AP belong belong to the same Multiple BSSID set. As another example, the co-MLD Multiple BSSID field is conveyed in the BSS parameter field to indicate whether the reported AP and other APs of the MLD to which the reporting AP is located are from the same Multiple BSSID. For example, the co-MLD bit in FIG. 14c is used to indicate the third relationship. The specific format is not limited in the present invention.

[0224] In another example, the RNR element may indicate one or more of the following two types: Signaling 1: Whether multiple reported APs are from the same MLD; Signaling 2: If multiple reporting APs are from the same multiple BSSID set.

[0225] Signaling 1 can be implemented by adding an MLD identifier to the information about the reported AP. If the MLD identifiers of multiple reported APs are the same, it indicates that multiple reported APs are from the same MLD. Signaling 2 can be implemented by adding a multiple BSSID set identifier to the information about the reported AP. If the multiple BSSID set identifiers of multiple reported APs are the same, it indicates that multiple reported APs are from the same multiple BSSID set. Optionally, if the MLD identifier conveyed in the information about the reported AP is a special value, e.g., 0, it indicates that the reported AP and the reporting AP belong to the same MLD. Optionally, if the multiple BSSID set identifier conveyed in the information about the reported AP is set to a special value, it indicates that the reported AP and the reporting AP belong to the same multiple BSSID set.

[0226] Based on the above-mentioned signaling, the RNR can indicate the relationship between the reported AP and the reporting AP, and the relationship between multiple reported APs, so that the station can obtain the relationship between the reported AP and the reporting AP, and the relationship between multiple reported APs, based on the above-mentioned signaling in the RNR element.

[0227] In addition, since the information of the reportee AP further includes a link identifier, the relationship between the APs can be determined based on the link identifier and the relationship between the link identifier and the MLD identifier and / or the Multiple BSSID set identifier. For example, FIG. 8A is further used as an example. The link ID of the reportee AP 2y is 2, and the MLD identifier is 1. The link ID of the reportee AP 3x is 4, and the MLD identifier is 1. It can be seen that the AP 2y and the AP 3x have the same MLD identifier and belong to the same MLD. It can also be seen that the AP with the link ID of 2 and the AP with the link ID of 4 belong to the same MLD. Therefore, since the link identifier of the reportee AP is unique, there is no need to additionally indicate the relationship between the reportee AP and the reporting AP, and the relationship between multiple reportee APs, in the MLD element. This can avoid repeated signaling indicators.

[0228] In another implementation, the signaling indicating the relationship between APs (eg, signaling 1 and signaling 2) may not be conveyed in the RNR element, but may be conveyed in the MLD element. The signaling is conveyed in sub-elements of each MLD element.

[0229] Part 2: MLD elements.

[0230] For the type of MLD element sent by the reporting AP and the structure of the MLD element sent, please refer to the description of embodiment 2. The details will not be described again here.

[0231] Part 3: Multiple BSSID elements.

[0232] If the reporting AP belongs to a Multiple BSSID set, the management frame further includes a Multiple BSSID element. The Multiple BSSID element includes information about one or more non-transmitting APs in the Multiple BSSID set to which the reporting AP belongs, and is called the non-transmitted BSSID profile. The non-transmitted BSSID profile conveys information about the non-transmitting APs and further includes the link IDs of the non-transmitting APs. This avoids the high signaling overhead and signaling redundancy caused by conveying multiple parameter information such as operating class, channel number, BSSID, etc.

[0233] There are two ways to convey the link identifier in the Multiple BSSID element, including but not limited to the following:

[0234] In the first method, if the non-transmitted AP indicated by the non-transmitted BSSID profile in the Multiple BSSID element further belongs to one MLD, and the non-transmitted BSSID profile of the non-transmitted AP further includes one MLD element, the sub-element in the MLD element indicates information about another AP of the MLD to which the non-transmitted AP belongs. In this case, the link identifier of the non-transmitted AP may be carried in the MLD element, such as being carried in the common information field of the MLD element. Optionally, the common control field of the MLD element further includes a link identifier (link ID) presence field, which indicates whether the link ID field appears or exists. Optionally, the structure of the Multiple BSSID element is shown in FIG. 12. In another example, the virtual MLD field and the special MLD field in FIG. 12 can be replaced with an MLD type indicator as the second structure of the Multiple BSSID element.

[0235] In the second method, the link identifier of the non-transmitting AP may be conveyed in the non-transmitted BSSID profile of the non-transmitting AP, but not in the MLD element. In the second implementation, the non-transmitted BSSID profile may or may not include the MLD element.

[0236] Since simplified information about non-transmitting APs is not conveyed in the RNR element, the following two implementations are provided in this embodiment of the present application to determine the relationship between a non-transmitting AP and another reporting AP.

[0237] Method 1. If the non-transmitting AP belongs to one MLD, the non-transmitted BSSID profile can carry one MLD element. The MLD element contains sub-elements to indicate information about other APs in the MLD to which the non-transmitting AP belongs, and indicates that the non-transmitting AP and the reportee AP belong to the same MLD. For example, as shown in FIG. 8A, AP1x sends the following management frame. AP1x and AP1y both belong to multiple BSS set 1. The RNR element may not carry information about AP1y. The Multiple BSSID element of the management frame carries the non-transmitted BSSID profile of AP1y. The non-transmitted BSSID profile further carries one MLD element. The sub-elements in the MLD element carry information about AP2z. The station receiving the management frame can determine the relationship between AP1y and another AP based on the RNR element and the Multiple BSSID element. AP1y and AP1x belong to multiple BSS set 1, and AP1y and AP2z belong to MLD3.

[0238] Method 2. The non-transmitted BSSID profile does not carry the MLD element. The non-transmitted BSSID profile must carry the MLD identifier. This identifier is used together with the MLD identifier in the information about the reported AP in the RNR to indicate whether the non-transmitted BSSID AP and the reported AP carried in the RNR are from the same MLD. For example, as shown in Figure 8A, AP1x sends the following management frame. AP1x and AP1y both belong to multiple BSS set 1. The RNR element may not carry the information about AP1y. The information about the reported AP in the RNR element includes the MLD identifier. That is, the information about AP2z includes the identifier of MLD3. The Multiple BSSID element of the management frame carries the non-transmitted BSSID profile of AP1y and the identifier of the MLD to which AP1y belongs. A station receiving the management frame can determine the relationship between AP1y and other APs based on the MLD identifier conveyed in the information about AP2z in the RNR element and the MLD identifier of AP1y conveyed in the Multiple BSSID element. AP1y and AP1x belong to multiple BSSID set 1, and AP1y and AP2z belong to MLD3.

[0239] Here, the signaling structure of the management frame is described by using FIG. 8a as an example. AP1x in AP MLD1 sends a management frame, for example a beacon frame, in a broadcast manner. As shown in FIG. 13a, the management frame carries one RNR information. The RNR element carries simplified information about AP2y, AP3x, AP2x, AP3y, and AP3z. The simplified information includes one-to-one correspondence between the link identifier of the AP and parameters such as the operation class, channel number, and BSSID of the AP. The management frame further carries three MLD information. The first MLD element is a formal MLD element, and the common information field includes the address of AP MLD1, and two sub-elements are carried, the first sub-element carries information about AP2y, and the second sub-element carries information about AP3x. The second MLD element is a virtual MLD element, the common information field contains the address of AP MLD2 and carries two sub-elements, the first sub-element carries information about AP2x and the second sub-element carries information about AP3y. The third MLD element is a special MLD element, the common information field is not present and one sub-element is carried, the sub-element carries information about AP3z. The link identifiers contained in the information about AP2y, AP3x, AP2x, and AP3z carried in the three MLD elements are the same as the link identifiers of these APs in the RNR element. Therefore, the MLD elements do not repeatedly carry one or more parameters such as the operating class, channel number, and BSSID carried in the RNR. This avoids signaling redundancy and reduces signaling overhead. Since the reporting AP1x belongs to the Multiple BSSID set, the management frame needs to carry an additional Multiple BSSID element. The element carries the non-transmitted BSSID profile, which is information about AP1y. Furthermore, since AP1y belongs to AP MLD3, the non-transmitted BSSID profile further carries the formal MLD element. The common information field contains the address of AP MLD3 and carries one subelement, which carries information about AP2z.The link identifier included in the information about AP2z is the same as the link identifier of AP2z in the RNR element. Optionally, the simplified information about AP1y may not be displayed in the RNR element. The parameters such as the operating class and channel number of the simplified information of AP1y are the same as those of the reporting AP1x. The information about the BSSID of AP1y can be carried in the non-transmitted BSSID profile of AP1y. Correspondingly, the station can know the information about AP1x, AP1y, AP2y, AP3x, AP2x, AP3y, and AP3z, and can further determine the relationship between the APs based on the RNR element, the three MLD elements, and the Multiple BSSID element in the management frame. Specifically, the station can determine the simplified information about the reported AP carried in the RNR and the other information about the reported AP carried in the MLD element based on the matching of the link IDs carried in the RNR element and the MLD element. As shown in FIG. 13a, the link ID of AP2y conveyed in the information about AP2y in the RNR is 2, and the link ID included in the first sub-element of the first MLD element is also 2. The station can determine the simplified information about AP2y in the RNR based on the match of the link IDs, and can determine other information about AP2y based on the first sub-element of the first MLD element. In addition, the station can further determine: AP1x and AP1y belong to Multiple BSSID Set 1, AP1x, AP2y, and AP3x belong to MLD1, AP2x and AP3y belong to MLD2, AP3z is a single-link device, AP2y, AP2x, and AP2z belong to Multiple BSSID Set 2, and AP3x, AP3y, and AP3z belong to Multiple BSSID Set 3.

[0240] The following uses FIG. 8A as an example to describe another signaling structure of a management frame. AP1x in AP MLD1 sends a management frame, for example a beacon frame, in a broadcast manner. As shown in FIG. 13B, the management frame carries one RNR information. The RNR element carries simplified information about AP2y, AP3x, AP2x, AP3y, and AP3z. The simplified information includes one-to-one correspondence between the link identifier of the AP and parameters such as the operation class, channel number, and BSSID of the AP. The information about each AP in the RNR element further includes an MLD identifier and / or a Multiple BSSID set identifier. Optionally, the management frame further carries three MLD information. The first MLD element is a formal MLD element, and the common information field includes the address of AP MLD1, and two sub-elements are carried, where the first sub-element carries information about AP2y, and the second sub-element carries information about AP3x. The second MLD element is a virtual MLD element, the common information field contains the address of AP MLD2 and carries two sub-elements, the first sub-element carries information about AP2x and the second sub-element carries information about AP3y. The third MLD element is a special MLD element, the common information field is not present and one sub-element is carried, the sub-element carries information about AP3z. The link identifiers contained in the information about AP2y, AP3x, AP2x, and AP3z carried in the three MLD elements are the same as the link identifiers of these APs in the RNR element. Therefore, the MLD elements do not repeatedly carry one or more parameters such as the operating class, channel number, and BSSID carried in the RNR. This avoids signaling redundancy and reduces signaling overhead. Since the reporting AP1x belongs to the Multiple BSSID set, the management frame needs to carry an additional Multiple BSSID element. The element conveys a non-transmitted BSSID profile, which is information about AP1y, including the link identifier of AP1y, and optionally further includes the MLD identifier of the MLD to which AP1y belongs.Optionally, the simplified information about AP1y may not be displayed in the RNR element. The parameters of the simplified information of AP1y, such as the operating class and channel number, are the same as those of the reporting AP1x. The information about the BSSID of AP1y can be conveyed in the non-transmitted BSSID profile of AP1y. Specifically, the parameters are calculated based on the reference BSSID (Transmitted BSSID) and the Multiple BSSID-index element in the non-transmitted BSSID profile. For the calculation method, see Draft P802.11REVmd_D3.0. Correspondingly, based on the RNR element, the three MLD elements, and the Multiple BSSID element in the management frame, the station can know the information about AP1x, AP1y, AP2y, AP3x, AP2x, AP3y, and AP3z, and can further determine the relationship between the APs. Specifically, the station can determine the simplified information about the reportee AP carried in the RNR and the other information about the reportee AP carried in the MLD element based on the matching of the link IDs carried in the RNR element and the MLD element. As shown in FIG. 13B, the link ID of AP2y carried in the information about AP2y in the RNR is 2, and the link ID included in the first sub-element of the first MLD element is also 2. The station can determine the simplified information about AP2y in the RNR based on the matching of the link IDs, and can determine the other information about AP2y based on the first sub-element of the first MLD element. Furthermore, the station can determine that AP1x and AP1y belong to Multiple BSSID Set 1. The station can determine that AP1x, AP2y, and AP3x all belong to MLD1, AP2x and AP3y all belong to MLD2, and AP3z is a single-link device based on the MLD identifier. Based on the Multiple BSSID set identifier, it can be determined that AP2y, AP2x, and AP2z belong to Multiple BSSID set 2, and AP3x, AP3y, and AP3z belong to Multiple BSSID set 3.

[0241] The following describes the implementation of the RNR element.

[0242] Reduced Neighbor Report element: An AP conveys a reduced neighbor report element in a management frame, such as a beacon frame or a probe response frame. During scanning, a station receives a management frame transmitted from an AP, obtains information about surrounding APs based on the reduced neighbor report element in the management frame, and then selects a suitable AP for association.

[0243] Specifically, a Reduced Neighbor Report element generally carries one or more Neighbor AP Information fields, which describe information about one or more neighbor APs and the BSS to which the neighbor AP belongs. The neighbor AP is also called a reported AP, and the AP that sends the RNR element is hereinafter called a reporting AP. The Neighbor AP Information field carries simplified information about the neighbor AP, i.e., the reported AP. Figure 14A shows a schematic diagram of the RNR element. From Figure 14B, it can be seen that the Neighbor AP Information field of the Reduced Neighbor Report element may include the following fields:

[0244] The TBTT Information Header (Target Beacon Transmission Time (TBTT) Information Header) field conveys the following information: A TBTT information field type field indicating the type of TBTT information and indicating the format of the TBTT information field together with the TBTT information length field; and A filtered neighbor AP field that indicates whether the SSIDs of all BSSs conveyed in the neighbor AP information field match the SSID of the probe request frame; Reserved field (1 bit), a TBTT information count field indicating the number of TBTT information fields contained in the TBTT information set; A TBTT information length field indicating the length of each TBTT information field. Table 4 shows the format of the specific information conveyed for different lengths. [Table 4]

[0245] If the TBTT information length is 12 bytes, the TBTT information field contains the following: A neighboring AP TBTT offset (neighboring AP target beacon transmission time offset) field indicating the offset between the neighboring AP's beacon transmission time and the reporting AP's beacon transmission time, and a BSSID (BSS identifier) ​​field indicating the BSS identifier corresponding to the neighboring AP; A short service set identifier (SSID) field indicating the service set identifier to which the neighboring AP belongs, and a BSS parameter field indicating the relevant parameters of the neighboring AP; As shown in Figure 14b, the BSS parameters field contains the following information: an OCT Recommended (On-Channel Tunneling Mechanism Recommended) field, which indicates that the neighboring AP expects to exchange management-type MPDUs with the reporting AP according to the OCT mechanism; A same service set identifier (SSID) field indicates whether the neighboring AP and the reporting AP have the same SSID; a Multiple Basic Service Set Identifier (BSSID) field indicates whether the neighboring AP is part of a Multiple BSSID set; A transmitted Basic Service Set Identifier (transmitted BSSID) field that indicates whether the neighboring AP is a transmitted or non-transmitted BSSID if the neighboring AP is part of a Multiple BSSID set; a member of extended service set with 2.4 / 5 GHz co-located AP field indicating whether the neighboring AP is a member of an extended service set with 2.4 / 5 GHz co-located APs (i.e., whether the neighboring AP is a 6 GHz-only AP); An unsolicited probe response active field that indicates whether the neighboring AP enables active probe responses.

[0246] Optionally, the TBTT information field further includes a co-located AP field, which indicates whether the neighbor AP and the reporting AP are co-located.

[0247] Optionally, the TBTT information field further includes a co-MLD field, which indicates whether the neighbor AP and the reporting AP are co-located.

[0248] Figure 14B is a schematic diagram of the format of the TBTT information field. Figure 14C is another schematic diagram of the TBTT information field.

[0249] In this embodiment, in a multi-AP multi-link device where a reporting AP is located, the RNR element and the Multiple MLD element are used together, and optionally the MLD element is also used, in order to prevent the reporting AP from broadcasting information about one or more or all APs. In order to prevent the AP's parameters such as the operation class, channel number, and BSSID from being repeated in subsequent multi-link operations, the AP's link identifier is added to the RNR element and the Multiple BSSID element. There is a correspondence between the AP's link identifier and the AP's parameters such as the operation class, channel number, and BSSID. In subsequent transmissions or communications, the AP's parameters such as the operation class, channel number, and BSSID do not need to be carried. This reduces the signaling overhead. In addition, the operation class and channel number of the non-transmitted BSSID in the Multiple BSSID element are the same as the operation class and channel number of the transmitted BSSID in the Multiple BSSID element, so the two parameters do not appear in the non-transmitted BSSID profile of the Multiple BSSID element. This further reduces the signaling redundancy.

[0250] The following describes in detail the devices provided in the embodiments of the present application.

[0251] FIG. 15 illustrates a communication device 1500 according to an embodiment of the present application. The device may be an access point AP (e.g., a reporting AP in an AP multilink device) or a station of the above-mentioned embodiment, or may be a chip or processing system in an access point AP (e.g., a reporting AP in an AP multilink device) or a station. The device may implement the methods and functions in any of the embodiments of the present application. Depending on the degree of integration, the communication device may include one or more of the components illustrated in FIG. 15. The components illustrated in FIG. 15 may include at least one processor 1501, a memory 1502, a transceiver 1503, and a communication bus 1504.

[0252] The components of the communication device 1500 are specifically described below with reference to FIG.

[0253] The processor 1501 is a control center of the communication device 1500 and may be a single processor or a collective term for multiple processing elements. For example, the processor 1501 may be a central processing unit (CPU) or an application specific integrated circuit (ASIC), or may be configured as one or more integrated circuits implementing embodiments of the present application, such as one or more microprocessors (digital signal processors (DSPs) or one or more field programmable gate arrays (FPGAs). The processor 1501 may implement various functions of the communication device by executing or executing software programs stored in the memory 1502 and calling up data stored in the memory 1502. During a particular implementation, in an embodiment, the processor 1501 may include one or more CPUs, such as CPU0 and CPU1 of FIG. 15.

[0254] Among particular implementations, in an embodiment, communication device 1500 may include multiple processors, such as processor 1501 and processor 1505 of FIG. 15. Each of the processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor, as used herein, may be one or more communication devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions).

[0255] The memory 1502 may be a read-only memory (ROM), another type of static storage and communication device capable of storing static information and instructions, or a random access memory (RAM), or another type of dynamic storage and communication device capable of storing information and instructions, or may be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or another compact disc storage device, an optical disc storage device (including a compact disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disc storage medium, or another magnetic storage and communication device, or any other medium that can be used to transmit or store program code expected in the form of instructions or data structures and that can be accessed by a computer. However, the memory 1502 is not limited here. The memory 1502 may exist independently or may be connected to the processor 1501 through a communication bus 1504. Alternatively, the memory 1502 may be integrated into the processor 1501. The memory 1502 is configured to store software programs for executing the solutions of the present application, and the processor 1501 controls the execution.

[0256] The transceiver 1503 is configured to communicate with another device (e.g., a station in the embodiment shown in FIG. 1). Of course, the transceiver 1503 can be further configured to communicate with a communication network, such as an Ethernet, a radio access network (RAN), or a Wireless Local Area Network (WLAN), etc. The transceiver 1503 can include a receiving unit for implementing a receiving function and a transmitting unit for implementing a transmitting function.

[0257] The communication bus 1504 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be classified as an address bus, a data bus, a control bus, etc. For ease of presentation, only one bold line is used to represent a bus in FIG. 15, but this does not imply that there is only one bus or only one type of bus.

[0258] For example, the communication device 1500 is a complete device. The communication device may include a processor 1501, a memory 1502, a transceiver 1503, and a communication bus 1504. Optionally, the communication device may further include other components, such as a display.

[0259] Optionally, the communication device 1500 is an access point AP (e.g., a reporting AP in an AP multilink device) and can be configured to implement the methods and functions related to the AP of the above-mentioned embodiment. For example, a computer program (instructions) is stored in the memory. When the processor calls the computer program, the above-mentioned methods and functions are implemented. For example, the processor is configured to generate a signaling or frame (transmitting MLD information), and the transceiver is configured to transmit the signaling or frame (transmitting MLD information). For example, the processor is configured to control the transceiver to perform step S101. Of course, the process of generating the MLD information in step S101 may also be achieved by the processor. In another example, the processor is configured to control the transceiver to perform step S201. Of course, the process of generating the management frame in step S201 may also be achieved by the processor. In yet another example, the processor is configured to control the transceiver to perform step S301. Of course, the process of generating the management frame in step S301 may also be achieved by the processor. In yet another example, the processor is configured to control the transceiver to execute step S401. Of course, the process of generating the management frame in step S401 may also be accomplished by the processor.

[0260] Optionally, the communication device 1500 is a station and can be configured to implement the methods and functions of the station in the above-mentioned embodiments. For example, the memory stores a computer program. When the processor invokes the computer program, the above-mentioned methods and functions are implemented. For example, the processor is configured to generate a signaling or frame (e.g., a probe response frame), and the transceiver is configured to transmit the signaling or frame (e.g., receive a probe request frame). In an example, the processor is configured to control the transceiver to receive MLD information in step S102, and the processor may then determine the structure of the multi-AP multilink device and information about each AP based on the MLD information, and further determine the AP for association. In another example, the processor is configured to control the transceiver to receive a management frame in step S202, and the processor may then determine the structure of the multi-AP multilink device and information about each AP based on the management frame, and further determine the AP for association. In yet another example, the processor may be configured to control the transceiver to receive the management frame in step S302, and then the processor may determine the structure of the multi-AP multilink device and information about each AP based on the management frame, and further determine the AP for association. In yet another example, the processor may be configured to control the transceiver to receive the management frame in step S402, and then the processor may determine the structure of the multi-AP multilink device and information about each AP based on the management frame, and further determine the AP for association.

[0261] In another example, the communication device 1500 is a chip system or a processing system in an access point AP (e.g., a reporting AP in an AP multilink device), so that a device equipped with the chip system or the processing system implements the method and function related to the AP in the above embodiment. In this case, the communication device 1500 may include some components shown in FIG. 15. For example, the communication device 1500 includes a processor. The processor is coupled to a memory and can call and execute instructions in the memory, so that a device configured with or installed with the chip system or the processing system implements the method and function of the above embodiment. Optionally, the memory may be a component in the chip system or the processing system, or a component coupled / connected to the outside of the chip system or the processing system. In an example, the chip system or the processing system may be installed in the access point AP (e.g., a reporting AP in an AP multilink device), so that the access point AP performs step S101 in the above embodiment. In another example, the chip system or the processing system may be installed in the access point AP, so that the access point AP performs step S201 in the above embodiment. In another example, a chip system or a processing system may be installed in the access point AP, so that the access point AP performs step S301 of the above embodiment. For example, the access point instructs step 401.

[0262] In yet another example, the communication device 1500 is a chip system or processing system in a station, so that a device equipped with the chip system or processing system implements the method and function related to the station in the above embodiment. In this case, the communication device 1500 may include some components shown in FIG. 15. For example, the communication device 1500 includes a processor. The processor is coupled to a memory and can call and execute instructions in the memory, so that a device configured with or installed with the chip system or processing system implements the method and function of the above embodiment. Optionally, the memory may be a component in the chip system or processing system, or a component coupled / connected to the outside of the chip system or processing system. In another example, the chip system or processing system may be installed in a station, so that the station performs step S102 in the above embodiment. In another example, the chip system or processing system may be installed in a station, so that the station performs step S202 in the above embodiment. In yet another example, the chip system or processing system may be installed in a station, so that the station performs step S302 in the above embodiment. In yet another example, a chip system or a processing system may be installed in a station to enable the station to perform step S402 of the above embodiment.

[0263] The chip system or the processing system may support communication according to the 802.11 series of protocols, for example, 802.11be, 802.11ax, and 802.11ac. The chip system may be installed in devices of various scenarios that support WLAN transmission. The devices of the WLAN transmission scenario are described at the beginning of this specification and will not be described in detail here.

[0264] In the embodiment of the present application, an access point AP (for example, a reporting AP in an AP multilink device) or a station can be divided into functional modules according to the above-mentioned method examples. For example, functional modules can be obtained through division based on corresponding functions, or two or more functions can be integrated into one processing module. The integrated module can be implemented in the form of hardware, or can be implemented in the form of software function modules. It should be noted that in the embodiment of the present application, module division is an example, and is merely a logical function division. In actual implementation, another division method can be used.

[0265] 16 is a schematic diagram of a configuration of a communication device 1600 when using an integrated unit. The communication device 1600 may be a multilink device, or a chip or a processing system in the multilink device. In the above method embodiments, the communication device 1600 may perform the operations of the multilink device. The communication device 1600 includes a processing unit 1601 and a transceiver unit 1602.

[0266] For example, the communications device 1600 may be an access point AP (eg, a reporting AP in an AP multilink arrangement) or a station as previously mentioned.

[0267] For example, the communication device 1600 is an access point or a chip within an access point.

[0268] The processing unit 1601 may be configured to control and manage the operation of the communication device 1600, such as for example generating MLD information, or in another example controlling the operation of the transceiver unit 1602. Optionally, if the communication device 1600 includes a storage unit, the processing unit 1601 may further execute programs or instructions stored in the storage unit, such that the communication device 1600 may implement the methods and functions of any of the above embodiments.

[0269] For example, the processing unit 1601 can control the transceiver unit to perform step S101 of Fig. 4, step S201 of Fig. 10A, step S301 of Fig. 10B, or step S401 of Fig. 11, and / or can be used for other processing of the technology described herein. All relevant contents of the steps in the above method embodiments may be cited in the functional description of the corresponding functional modules. The details will not be described again here.

[0270] For example, the processing unit 1601 can control the transceiver unit to perform, for example, step S102 of Fig. 4, S202 of Fig. 10A, S302 of Fig. 10B, or S402 of Fig. 11, and / or can be used for other processing of the techniques described herein. All relevant contents of the steps in the above method embodiments may be cited in the functional description of the corresponding functional modules. Details will not be described again here.

[0271] For example, the transceiver unit 1602 may transmit and receive data or signaling transmitted over one link, or transmit and receive data or signals transmitted over multiple links. Optionally, the transceiver unit 1602 may be a transceiver module or may include multiple transceiver modules. If the transceiver unit 1602 is a transceiver module, the transceiver module may transmit and receive data over multiple links. For example, if the first multilink device operates over two links, when the transceiver unit 1602 includes two transceiver modules, one transceiver module operates over one link and the other transceiver module operates over the other link. For example, the transceiver unit 1602 may be configured to perform, for example, step S101 of FIG. 4, step S201 of FIG. 10A, step S301 of FIG. 10B, or step S401 of FIG. 11, and / or be used for another process of the techniques described herein. All relevant contents of the steps in the foregoing method embodiments may be cited in the functional descriptions of the corresponding functional modules, and the details will not be described again here.

[0272] For example, the communication device 1600 may be the communication device shown in FIG. 15, the processing unit 1601 may be the processor 1501 in FIG. 15, and the transceiver unit 1602 may be the transceiver 1503 in FIG. 15. Optionally, the communication device 1600 may further include a memory. The memory is configured to store corresponding program codes and data for the communication device 1600 to perform any communication method between the above multi-link devices. For the functional description of the corresponding components of the communication device 1600, reference may be made to the description of all the relevant contents of the components in FIG. 15, and the details will not be described again here.

[0273] For example, the communication device 1600 may alternatively be a chip or processor, the processing unit 1603 being a processing circuit within the chip or processor, and the transceiver unit 1602 being an input / output circuit within the chip or processor, the input / output circuit being an interface for intercommunication or data exchange between the chip or processor and another coupled component, such that signaling or data information or program instructions are input to the chip or processor for processing, and the processed data or signaling is output to another coupled component, controlling the first multilink device in which the chip or processor is installed to implement a function.

[0274] In another example, the communications device 1600 is a station or a chip within a station.

[0275] The processing unit 1601 may be configured to control and manage the operation of the communication device 1600, such as for example processing MLD information, or in another example, controlling the operation of the transceiver unit 1602. Optionally, if the communication device 1600 includes a storage unit, the processing unit 1601 may further execute programs or instructions stored in the storage unit, such that the communication device 1600 may implement the methods and functions of any of the above embodiments.

[0276] For example, the processing unit 1601 can be configured to process MLD information. For example, the MLD information of step S102 of Fig. 4 is processed by the processing unit 1601, or the management frame of S202 of Fig. 10A, the management frame of S302 of Fig. 10B, or the management frame of S402 of Fig. 11 is processed by the processing unit 1601, and / or the processing unit 1601 is used for other processing of the technology described in this specification. All the relevant contents of the steps in the above-mentioned method embodiments may be cited in the functional description of the corresponding functional modules. The details will not be described again here.

[0277] For example, the transceiver unit 1602 transmits and receives data or signaling transmitted on one link, or transmits and receives data or signals transmitted on multiple links. Optionally, the transceiver unit 1602 may be one transceiver module or may include multiple transceiver modules. If the transceiver unit 1602 is one transceiver module, the transceiver module can transmit and receive data on multiple links. For example, if the first station operates on two links, when the transceiver unit 1602 includes two transceiver modules, one transceiver module operates on one link and the other transceiver module operates on the other link. For example, the transceiver unit 1602 may be configured to perform, for example, step S102 of FIG. 4, S202 of FIG. 10A, S302 of FIG. 10B, or S402 of FIG. 11, and / or be used for other processing of the techniques described herein. All relevant contents of the steps in the above-mentioned method embodiments may be cited in the functional description of the corresponding functional modules. The details will not be described again here.

[0278] For example, the communication device 1600 may be the communication device shown in Fig. 15, the processing unit 1601 may be the processor 1501 in Fig. 15, and the transceiver unit 1602 may be the transceiver 1503 in Fig. 15. Optionally, the communication device 1600 may further include a memory. The memory is configured to store corresponding program codes and data for the communication device 1600 to perform the above-mentioned method. The functional description of the corresponding components of the communication device 1600 may refer to the description of all the relevant contents of the components in Fig. 15, and the details will not be described again here.

[0279] For example, the communications device 1600 may alternatively be a chip or processor, the processing unit 1603 being a processing circuit within the chip or processor, and the transceiver unit 1602 being an input / output circuit within the chip or processor, the input / output circuit being an interface for intercommunication or data exchange between the chip or processor and other coupled components, such that signaling or data information or program instructions are input to the chip or processor for processing, and the processed data or signaling is output to another coupled component to control the device in which the chip or processor is installed to implement a function.

[0280] In addition, in the device embodiment, for the signaling structure of MLD information and the structure of the management frame, please refer to the description of the above embodiment.

[0281] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program code, and when the processor executes the computer program code, the electronic device (e.g., AP or station) in which the processor is located can execute the method of any of the embodiments.

[0282] An embodiment of the present application further provides a computer program product, which when executed on a computer, enables the computer (e.g., an AP or a station) to perform the functionality of any of the above-mentioned embodiments and methods.

[0283] An embodiment of the present application further provides a communication device. The device may be in the product form of a chip. The structure of the device includes a processor and an interface circuit. The processor is configured to communicate with another device through the receiving circuit and enable the communication device to perform the method in any of the embodiments.

[0284] An embodiment of the present application further provides a communication system. The communication system includes the above-mentioned access point AP (e.g., a reporting AP in an AP multilink device) and a station. The access point AP (e.g., a reporting AP in an AP multilink device) and a station can execute the method (e.g., the method of FIG. 4, FIG. 10A, FIG. 10B, or FIG. 11) in any of the above-mentioned embodiments. The method or algorithm steps described in connection with the contents disclosed in this application may be implemented by hardware or may be implemented by a processor by executing software instructions. The software instructions may include corresponding software modules. The software modules may be stored in a random access memory (RAM), a flash memory, an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a register, a hard disk, a mobile hard disk, a compact disk read-only memory (CD-ROM), or any other form of storage medium well known in the art. For example, a storage medium may be coupled to a processor such that the processor can read information from, or write information to, the storage medium. Of course, the storage medium may alternatively be a component of the processor. The processor and the storage medium may reside in an ASIC. Further, the ASIC may reside in a core network interface device. Of course, the processor and the storage medium may reside in a core network interface device as discrete components.

[0285] Those skilled in the art should recognize that in one or more of the above examples, the functions described herein may be implemented by hardware, software, firmware, or any combination thereof. If the functions are implemented by software, the functions described above may be stored on a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media may include computer-readable storage media and communication media, and further include any medium that facilitates the transmission of a computer program from one place to another. Storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0286] In the above specific implementation, the objectives, technical solutions and beneficial effects of the present application are further described in detail. It should be understood that the above description is only a specific implementation of the present application, and is not intended to limit the protection scope of the present application. Any modifications, equivalent replacements or improvements made based on the technical solutions of the present application should be encompassed within the protection scope of the present application.

Claims

1. A method for exchanging signaling information in a wireless local area network (WLAN), comprising: generating a management frame by a reporting access point (AP), the reporting AP belonging to a first AP multi-link device (MLD), the management frame including a first MLD element indicating a first AP MLD, a second MLD element indicating another AP MLD different from the first AP MLD, and a Multiple BSSID (basic service set identifier) ​​element, the Multiple BSSID element including information about another AP belonging to the same Multiple BSSID set as the reporting AP; transmitting, by the reporting access point, the management frame; The method includes:

2. A method for exchanging signaling information in a wireless local area network (WLAN), comprising: receiving, by a station, a management frame from a reporting access point (AP), the reporting AP belonging to a first AP multi-link device (MLD), the management frame including a first MLD element indicating the first AP MLD, a second MLD element indicating another AP MLD different from the first AP MLD, and a Multiple BSSID (basic service set identifier) ​​element, the Multiple BSSID element including information about another AP belonging to the same Multiple BSSID set as the reporting AP; obtaining, by the station, information about the other AP based on the management frame; The method includes:

3. The method of claim 1 or 2, wherein the first MLD element includes a common control field, the common control field including type information indicating an MLD element type of the first MLD element.

4. The method of claim 3 , wherein the first MLD element is an authoritative MLD element, and the type information in the first MLD element indicates that the first MLD element is the authoritative MLD element.

5. The method according to any one of claims 1 to 4, wherein the second MLD element includes a common control field, the common control field including type information indicating that the second MLD element is a virtual MLD element.

6. The method according to any one of claims 1 to 5, wherein the management frame further comprises a Reduced Neighbor Report (RNR) element.

7. The method of claim 6, wherein, when multiple reporting APs are from the same MLD, in the RNR element, the MLD identifiers of the multiple reporting APs are the same.

8. The method according to any one of claims 1 to 7, wherein the management frame is a beacon frame, an association response frame, a probe response frame, an authentication frame or a neighbour report.

9. An access point (AP), comprising a processor and a memory, the memory configured to store instructions that, when executed by the processor, enable the AP to perform the method of any one of claims 1, 3 to 8.

10. A station comprising a processor and a memory, the memory configured to store instructions which, when executed by the processor, enable the station to perform a method according to any one of claims 2 to 8.

11. A chip comprising an input / output interface circuit and a processing circuit, the input / output interface circuit configured to input / output data or signaling information, and the processing circuit configured to process the data or signaling information provided by the input / output interface circuit to enable an apparatus including the chip to perform a method according to any one of claims 1 to 8.

12. A computer readable storage medium storing computer program code or instructions which, when executed on a processor, enable an apparatus including the processor to perform a method according to any one of claims 1 to 8.

13. A computer program, which when executed on a processor, enables a device including said processor to carry out the method according to any one of claims 1 to 8.

14. A communication system, the communication system comprising an access point according to claim 9 and a station according to claim 10.

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