Access point multilink device, communication method and integrated circuit

Abstract

An access point multilink device is provided with: a first virtual AP corresponding to a first BSSID, which is a first transmission BSSID affiliated to a first multi-BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, which is either a second transmission BSSID or a second non-transmission BSSID affiliated to a second multi-BSSID set for a second channel, the first virtual AP notifying a first common SSID for the first BSSID and the second BSSID on the first channel, the first virtual AP being provided with: a circuit configured to generate a first common SSID for the first BSSID and the second BSSID; generating a frame comprising an SSID field representing the first common SSID, a multi-link element for the AP MLD, the multi-link element comprising a MAC address of the AP MLD, a multi-BSSID element for the other AP MLD, the multi-BSSID element comprising a non-transport BSSID profile of a first non-transport BSSID affiliated to the first set of multi-BSSIDs; and a transmission unit that transmits the frame on the first channel.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of June 1, 2021, application number 202180044029.8, invention name “Communication device and communication method for EHT virtualization of multi-link equipment”, and applicant “Panasonic Electric (USA) Intellectual Property Corporation”. Technical Field

[0002] The present embodiments relate generally to communication devices, and more particularly to methods and apparatus for Extreme High Throughput (EHT) virtualization of Multi-Link Devices (MLDs). Background Art

[0003] In the standardization of next-generation wireless local area networks (WLANs), a new radio access technology with backward compatibility with IEEE 802.11a / b / g / n / ac / ax technologies has been discussed in the IEEE 802.11 working group and named 802.11be Extremely High Throughput (EHT) WLAN.

[0004] In IEEE 802.11be EHT WLAN, in order to provide better link adaptation and higher throughput on 802.11ax High Efficiency (HE) WLAN, it is expected to increase the maximum channel bandwidth from 160 MHz to 320 MHz, increase the maximum number of space-time streams from 8 to 16, and support multi-link operation.

[0005] Additionally, to enable multilink operation between access point (AP) multilink devices (MLDs) and non-AP MLDs, multilink setup can be performed on one of the supported links to establish associations for attached stations (STAs) in one or more links. Virtual APs (VAPs) can also be implemented.

[0006] However, there has been no discussion to date on EHT virtualization of MLD devices, especially regarding interconnection with virtual LANs (VLANs).

[0007] Therefore, there is a need for a communication device and method that can solve the above-mentioned problems. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure. Summary of the Invention

[0008] Non-limiting and exemplary embodiments facilitate providing a communication apparatus and a communication method for EHT virtualization of MLD devices.

[0009] According to one aspect of the present disclosure, an access point multi-link device (AP MLD) is provided, which is an access point multi-link device to which multiple access points (APs) are attached. The device includes: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multiple BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multiple BSSID set for a second channel, the first virtual AP advertising a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel, the first virtual AP including: a circuit for generating a frame including an SSID field indicating the first public SSID, a multi-link element for the AP MLD, and a multi-BSSID element for other AP MLDs, the multi-link element including a MAC address of the AP MLD, the multi-BSSID element including a non-transmission BSSID profile of a first non-transmission BSSID attached to the first multiple BSSID set; and a transmitting unit for transmitting the frame on the first channel.

[0010] According to one aspect of the present disclosure, a communication method is provided, which is a communication method in an access point multi-link device AP MLD to which multiple access points APs are attached, wherein the AP MLD includes: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multi-BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multi-BSSID set for a second channel, the first virtual AP advertising a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel, the communication method comprising: a frame generating step, wherein the first virtual AP generates a frame including an SSID field indicating the first public SSID, a multi-link element for the AP MLD, and a multi-BSSID element for other AP MLDs, the multi-link element including the AP The multi-BSSID element includes a non-transmission BSSID profile of a first non-transmission BSSID attached to the first multi-BSSID set; and a frame transmission step of transmitting the frame on the first channel through the first virtual AP.

[0011] According to one aspect of the present disclosure, an integrated circuit is provided, which is an integrated circuit for an access point multi-link device (AP MLD) to which multiple access points (APs) are attached. The AP MLD includes: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multiple BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multiple BSSID set for a second channel. The first virtual AP advertises a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel. The integrated circuit controls: a frame generation step, wherein the first virtual AP generates a frame including an SSID field indicating the first public SSID, a multi-link element for the AP MLD, and multi-BSSID elements for other AP MLDs, the multi-link element including the AP MLD. The multi-BSSID element includes a non-transmission BSSID profile of a first non-transmission BSSID attached to the first multi-BSSID set; and a frame transmission step of transmitting the frame on the first channel through the first virtual AP.

[0012] According to one aspect of the present disclosure, there is provided an AP included in a plurality of access points (APs) attached to an AP multi-link device (MLD), wherein each of the plurality of APs advertises a basic service set identifier (BSSID) and provides a link identified by a link identifier (ID), the AP comprising: a circuit that, in operation, generates a multi-link element carrying information about the AP MLD and the plurality of APs; and a transmitter that, in operation, transmits a frame on a link, the multi-link element indicating a link ID of the link on which the frame is transmitted.

[0013] According to another aspect of the present disclosure, a non-AP station (STA) included in a plurality of non-AP stations (STAs) attached to a non-AP MLD is provided, the non-AP STA including: a circuit operable to generate a probe request frame carrying a multilink element including an MLD MAC address of the AP MLD and one or more link IDs of links attached to the AP MLD; and a transmitter operable to transmit the probe request frame to request information about the AP MLD and the one or more links of the AP MLD.

[0014] According to another aspect of the present disclosure, a communication method is provided, including: generating a frame at an AP included in a plurality of APs affiliated with an AP MLD, wherein each of the plurality of APs advertises a BSSID and provides a link identified by a link ID, the frame carrying a multilink element containing information about the AP MLD and the plurality of APs; and transmitting the frame on the link, the multilink element indicating the link ID of the link on which the frame is transmitted.

[0015] It should be noted that the general or specific embodiments can be implemented as systems, methods, integrated circuits, computer programs, storage media, or any selective combination thereof. Additional benefits and advantages of the disclosed embodiments will become apparent from the description and drawings. Benefits and / or advantages can be achieved individually by various embodiments and features of the description and drawings, and all of these benefits and / or advantages do not need to be provided to achieve one or more of such benefits and / or advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, in which like reference numerals refer to identical or functionally similar elements throughout the several views and which are incorporated into and constitute a part of the specification together with the following detailed description, serve to illustrate various embodiments and to explain various principles and advantages according to the present embodiments.

[0017] Figure 1 An implementation of VLANs according to an example is illustrated.

[0018] Figure 2 An implementation of a network according to an example is illustrated.

[0019] Figure 3 Depicted is a diagram of AP MLD with layer 1 virtualization in accordance with various embodiments.

[0020] Figure 4A and Figure 4B Illustrated is an implementation of a layer 1 virtualized network with only physical APs according to various embodiments.

[0021] Figure 4C An authentication frame for requesting authentication for a specific SSID is illustrated.

[0022] Figure 5A and Figure 5B Illustrated is an implementation of a network with layer 1 virtualization without any interconnection with VLANs according to various embodiments.

[0023] Figure 6A and Figure 6B Illustrated is an implementation of a network with layer 1 virtualization using a combination of physical APs and VAPs according to various embodiments.

[0024] Figure 7Describes the use Figures 4A to 6B Illustration of broadcast 802.11 frames and 802.3 frames for the network shown in .

[0025] Figure 8 Depicted is a diagram of AP MLD with layer 1 virtualization and shared upper layer medium access control (UMAC) structure in accordance with various embodiments.

[0026] Figure 9 Depicted are diagrams of co-located APs grouped into two or more AP groups to create multiple APMLDs for layer 2 virtualization in accordance with various embodiments.

[0027] Figure 10A and Figure 10B Illustrated is an implementation of a network with layer 2 virtualization using multiple AP MLDs according to various embodiments.

[0028] Figure 11A and Figure 11B Illustrated is an implementation of a network with layer 2 virtualization using multiple AP MLD with only physical APs in accordance with various embodiments.

[0029] Figure 12 Describes the use Figures 10A to 11B Illustration of broadcast 802.11 frames and 802.3 frames for the network shown in .

[0030] Figure 13 Depicted is a diagram of Layer 2 AP MLD without hypervisor virtualization in accordance with various embodiments.

[0031] Figure 14 Depicted is a diagram of Layer 2 AP MLD with hypervisor virtualization in accordance with various embodiments.

[0032] Figure 15 Depicted are diagrams of multilink elements configured for unified signaling in accordance with various embodiments.

[0033] Figure 16 Depicted is a simplified diagram of a beacon / broadcast probe response frame configured for layer 1 virtualization with all physical APs according to a first embodiment.

[0034] Figure 17 The first embodiment is described as follows Figure 4A and Figure 4B Illustration of a beacon frame transmitted by AP-1 of the network shown.

[0035] Figure 18 Depicted is a simplified diagram of a beacon / broadcast probe response frame configured for layer 1 virtualization using a VAP according to a first embodiment.

[0036] Figure 19 The first embodiment is described as follows Figure 6A and Figure 6B Illustration of a beacon frame transmitted by AP-1 of the network shown.

[0037] Figure 20 The first embodiment is described as follows Figure 6A and Figure 6B Illustration of a beacon frame transmitted by VAP-3 of the network shown.

[0038] Figure 21 The first embodiment is described as follows Figure 6A and Figure 6B Illustration of a beacon frame transmitted by VAP-5 of the network shown.

[0039] Figure 22 Depicted is a simplified diagram of a beacon / probe response frame configured for layer 2 virtualization according to a first embodiment.

[0040] Figure 23 The first embodiment is described as follows Figure 10A and Figure 10B Illustration of a beacon frame transmitted by VAP-1 of the network shown in .

[0041] Figure 24 The first embodiment is described as follows Figure 10A and Figure 10B Illustration of a beacon frame transmitted by VAP-4 of the network shown in .

[0042] Figure 25 The first embodiment is described as follows Figure 10A and Figure 10B Illustration of a beacon frame transmitted by VAP-6 of the network shown.

[0043] Figure 26 The first embodiment describes the transmission of the non-AP MLD to the Figure 10A and Figure 10B FIG. 4 is an illustration of a probe request frame of VAP-1 of the network shown in FIG.

[0044] Figure 27 Described according to the first embodiment Figure 10A and Figure 10B The illustrated network is a diagram of a probe response frame transmitted by VAP-1 to a non-APMLD.

[0045] Figure 28 Depicted is a simplified illustration of a beacon / probe response frame according to a second embodiment.

[0046] Figure 29 Depicted is a diagram of a Neighbor Report (NR) element according to a second embodiment.

[0047] Figure 30 Depicted is a diagram of a Reduced Neighbor Report (RNR) element in accordance with a second embodiment.

[0048] Figure 31 Depicted is a simplified illustration of a beacon / probe response frame according to a third embodiment.

[0049] Figure 32 The third embodiment is described as follows Figure 10A and Figure 10B Illustration of a beacon frame transmitted by VAP-1 of the network shown in .

[0050] Figure 33 The following is a diagram illustrating a method according to a third embodiment. Figure 32 Illustration of the Reduced Neighbor Report element in a beacon frame shown in .

[0051] Figure 34 Depicted is a diagram of multilink elements for unified signaling according to a fourth embodiment.

[0052] Figure 35 The fourth embodiment is described as follows Figure 10A and Figure 10B Illustration of a beacon frame transmitted by VAP-1 of the network shown in .

[0053] Figure 36 The fourth embodiment is described as follows Figure 10A and Figure 10B Illustration of neighbor MLD report elements transmitted by VAP-6 for the network shown in FIG.

[0054] Figure 37 The fourth embodiment is described as follows Figure 10A and Figure 10B Illustration of the RNR elements of a VAP-6 transmission for the network shown in .

[0055] Figure 38 Describes the transmission to the Figure 10A and Figure 10B FIG. 4 is an illustration of an association request frame of VAP-1 of the network shown in FIG.

[0056] Figure 39 Describes the transmission to the Figure 10A and Figure 10B FIG4 is an illustration of a multilink reset frame in which VAP-1 of the network is shown updating the L2 MAC address.

[0057] Figure 40 Depicted is a simplified illustration of a beacon / probe response frame according to a fifth embodiment.

[0058] Figure 41 The fifth embodiment is described as follows Figure 10A and Figure 10B Illustration of the RNR elements transmitted by VAP-1 of the network shown in .

[0059] Figure 42 Depicted is a diagram of an AP MLD concurrently serving legacy devices and MLD according to a sixth embodiment.

[0060] Figure 43A Depicted is a simplified illustration of a beacon / probe response frame according to a sixth embodiment.

[0061] Figure 43B Depicted is a diagram of an RNR element according to a sixth embodiment.

[0062] Figure 44A Depicted is a simplified diagram of a broadcast data frame according to a sixth embodiment.

[0063] Figure 44B Depicted is a simplified diagram of a broadcast management frame according to a sixth embodiment.

[0064] Figure 44C Depicted is a simplified diagram of a generic MAC frame according to a sixth embodiment.

[0065] Figure 45 Shown is a flow chart illustrating a method for EHT virtualization of MLD devices according to various embodiments.

[0066] Figure 46 A schematic partial cross-sectional view of one of the subordinate APs or STAs of a multi-link device that may be implemented for EHT virtualization of an MLD device according to various embodiments is shown.

[0067] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. DETAILED DESCRIPTION

[0068] The following detailed description is merely exemplary in nature and is not intended to limit the embodiments or the application and uses of the embodiments. Furthermore, there is no intention to be bound by any theory presented in the foregoing background technology or this detailed description. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and the background of the present disclosure.

[0069] VAPs enable a physical AP to function as two or more logical APs. Generally speaking, all VAPs in a network operate on the same channel. The BSSIDs (Basic Service Set Identifiers) corresponding to different VAPs typically have different settings (security, Quality of Service (QoS), etc.).

[0070] There are two main ways to implement VAP:

[0071] - Legacy method (co-hosted BSSID): Each VAP transmits a unique beacon frame.

[0072] -Multi-BSSID: A single beacon frame carries information about all VAPs. The BSSID that transmits the beacon frame is the transmission BSSID, and the rest are non-transmission BSSIDs. A maximum of eight VAPs can be supported.

[0073] VLANs logically group two or more devices together, regardless of their physical location on the wired network. For simplicity, improved security, and traffic management, VLANs allow devices on the same physical network to be partitioned into separate broadcast domains. Each VLAN is identified by a VLAN ID. One of the primary goals of implementing VLANs is to reduce broadcast traffic. VLAN specifications are standardized by IEEE 802.1Q.

[0074] A common method for extending VLANs to wireless LANs is to create a separate service set identifier (SSID) for each VLAN. It's also possible for more than one VLAN to be mapped to an SSID. Each SSID is then mapped to a VAP (BSSID). Frames destined for different VLANs are wirelessly transmitted by the VAP over different SSIDs, ensuring that only clients associated with that VLAN receive those packets.

[0075] Figure 1The diagram illustrates an example of how VLANs can be implemented. In a network 100, there are n VAPs, namely, VAP-1 102, VAP-2 104, through VAP-n 106. BSSID-1 108 corresponds to VAP-1 102, BSSID-2 110 corresponds to VAP-2 104, and BSSID-n 112 corresponds to VAP-n 106. The network also has n VLANs, namely, VLAN1 114, VLAN2 116, through VLANn 118. For example, VLAN1 114 is designated for employees and mapped to SSID: Staff, VLAN2 116 is designated for guests and mapped to SSID: Guest, and VLANn 118 is designated for IoT (Internet of Things) use and mapped to SSID: IoT. Each of these SSIDs is then mapped to a VAP. SSID: Staff is mapped to VAP-1 102 (or BSSID-1 108), SSID: Guest is mapped to VAP-2 104 (or BSSID-2 110), and SSID: IOT is mapped to VAP-n 106 (or BSSID-112). Although all VAPs and non-AP STAs operate on the same channel, only non-AP STA-1 120 can receive packets transmitted by VAP-1 102, only non-AP STA-2 122 can receive packets transmitted by VAP-1 104, and only non-AP STA-n 124 can receive packets transmitted by VAP-1 106.

[0076] Typically, VLANs are mapped to SSIDs; in legacy systems, BSSIDs and SSIDs are mapped one-to-one, so this is straightforward. However, with MLD, the mapping of SSIDs to BSSIDs is not as clear as there are multiple ways to do this. Figure 2 In the exemplary system shown in FIG, AP MLD 202 includes AP-1 204 and AP-2 206. AP-1 204 operates two virtual APs: VAP-1.1 208 and VAP-1.2 210. This allows AP MLD 202, which has only two physical APs (AP-1 204 and AP-2 206), to support three SSIDs (SSID: Staff, SSID: Guest, and SSID: IOT) or VLANs (VLAN 1 212, VLAN 2 214, and VLAN n 216). However, in such a deployment, it is not possible to support non-AP MLDs because non-AP MLDs operate concurrently on multiple links and can theoretically join multiple SSIDs. However, due to security and other considerations, they should not be allowed to join multiple SSIDs simultaneously.

[0077] To address the aforementioned issues, this disclosure proposes a two-layer approach to virtualization using Multi-Link Layer (MLD). Furthermore, unified signaling, which supports diverse virtualization architectures and usages, is proposed to enable MLD to quickly find information about other links within a peer link (e.g., during discovery, multi-link setup, etc.).

[0078] In Layer 1 virtualization, APs in an AP MLD are grouped into two or more AP groups to create multiple virtual AP MLDs from a single AP MLD. A single MLD MAC address is assigned to the DS (Distribution Service) and a single MAC-SAP (Media Access Control - Service Access Point). Each AP MLD can have two or more SSIDs and multiple virtual networks. Layer 1 virtualization is advantageous for small deployments requiring only a few virtual networks, such as home networks or small businesses. It is simple to implement and requires minimal hardware. SSID reconfiguration is also easier because there is no need to redefine the MLD.

[0079] In Layer 2 virtualization, co-located APs are grouped into two or more AP groups to create multiple AP MLDs. There can be multiple MLD MAC-SAPs to the DS, as well as multiple MLD MAC addresses, one for each AP MLD. Each AP MLD has a single SSID, and there is one AP MLD per virtual network. The advantage of Layer 2 virtualization is that it is suitable for large deployments requiring more virtual networks, such as enterprise networks or large venues (e.g., airports). However, compared to Layer 1 virtualization, the implementation can be complex and require higher hardware requirements.

[0080] Figure 3A diagram of an AP MLD 300 implementing Layer 1 virtualization according to various embodiments is depicted. AP MLD 300 includes AP-1 302, AP-2 304, AP-3 306, and AP-4 308. AP-1 302 and AP-2 304 form virtual AP MLD-1 310, while AP-3 306 and AP-4 308 form virtual AP MLD-2 312. Additionally, virtual AP MLD-1 310 is mapped to SSID-1, while virtual AP MLD-2 312 is mapped to SSID-2. In other words, the APs of AP MLD 300 are grouped into two or more AP groups to create multiple virtual AP MLDs from a single AP MLD. Each group of APs is mapped to a unique SSID, so that all APs of a virtual AP MLD advertise the same SSID, allowing each AP MLD to have two or more SSIDs. In this Layer 1 virtualization example, there is a single MLD MAC address and a single MAC-SAP to the DS. Non-AP MLDs only allow multilink setup for links that are part of the same virtual AP MLD (i.e., the same SSID). An ID can also be assigned to the virtual MLD for easier identification.

[0081] Figure 4A and Figure 4B An implementation of a network 400 with layer 1 virtualization only for physical APs is illustrated in accordance with various embodiments. Figure 4A In network 400, AP MLD 402's four physical APs are divided into two groups. AP-1 404 (corresponding to BSSID-1.1 420) and AP-2 406 (corresponding to BSSID-1.2 422) advertise the SSID: Staff. AP-3 408 (corresponding to BSSID-2.2 424) and AP-4 410 (corresponding to BSSID-2.1 426) advertise the SSID: Guest. SSID: Staff is mapped to VLAN 1 412, while SSID: Guest is mapped to VLAN 2 414. In other words, AP MLD 402 bridges wireless frames between APs and VLANs, mapping each SSID to the corresponding VLAN. Non-AP MLD-1 416 is associated with SSID: Staff, while non-AP MLD-2 418 is associated with SSID: Guest. Figure 4BAn alternative view of four APs is shown. AP-1 404, AP-2 406, AP-3 408, and AP-4 410 operate on links 1, 2, 3, and 4 with link IDs 1, 2, 3, and 4, respectively. The link ID uniquely identifies the BSSID of the AP attached to the AP MLD. The link ID is also associated with the operating channel (i.e., operating class and channel number) associated with the BSSID, but the link ID remains the same even if the operating channel changes. In this example, the wireless network represented by SSID Staff operates on links 1 and 2, while the wireless network represented by SSID Guest operates on links 3 and 4. Example MAC addresses for AP MLD 402 and the four APs are shown below:

[0082] -MLD MAC address = 0A-20;

[0083] -BSSID-1.1 (AP-1) = 0A-21; BSSID-1.2 (AP-2) = 0A-22;

[0084] -BSSID-2.1 (AP-3) = 0D-21; BSSID-2.2 (AP-4) = 0D-22;

[0085] For simplicity, the MAC address is shown as only 2 octets, rather than the full 6 octets. Advantageously, this implementation of network 400 is simple and suitable for AP MLD with 3 or more APs. However, only a limited number of VLANs can be supported using this approach.

[0086] As a further analysis, the implementation of network 400 is equivalent to logically splitting the MLD into 2 virtual MLDs. During discovery, different APs can advertise different SSIDs. For multi-link setup, the non-AP MLD only requests the setup of links belonging to the SSID of interest. In terms of security, the group key (GTK / IGTK) is allowed to be different for different links, so there is no problem. The pairwise key (PTK) is the same for all links, but there is no problem because the PTK only applies to a single non-AP MLD. However, all SSIDs will have the same security scheme (e.g., WPA-2). In some security associations, such as Simultaneous Authentication of Peers (SAE), the SSID of the network and the corresponding password are used to generate a session-specific password element (PWE) for the ECC group. Specifically, the SSID and password are used to generate a password seed, which in turn is used to generate the PWE:

[0087] PasswordSeed = HKDF-Extract(ssid, password[|| identifier])

[0088] Here, HKDF-Extract is the hash function defined in IETF RFC 5869, and [|| identifier] indicates that the password identifier (if present) is optionally included. In such cases, although the security associations between different non-AP MLDs and AP MLDs occur on the same MAC-SAP, different non-AP MLDs will use different SSID and password combinations to generate PWE, depending on which SSID the non-AP MLD is joining. Since PWE is used in the SAE Submit message (during authentication), in such cases, the non-AP MLD or non-AP STA also includes the SSID field in the authentication frame to explicitly inform the AP MLD which SSID it is requesting authentication for. This is in Figure 4C , where the non-AP MLD indicates in the authentication frame 430 transmitted by the non-AP MLD to the AP MLD that it is requesting authentication with the network Staff by including the SSID field 432 set to Staff in the authentication frame 430. Since the AP MLD knows which SSID the non-AP MLD is joining, there is no confusion on the AP MLD side about how to generate the PWE.

[0089] For interconnection with VLANs, a VLAN ID is mapped to an SSID. MLD ensures that incoming frames (from the DS) are sent to the correct SSID (BSSID) based on their VLAN ID, while also attaching the correct VLAN ID to outgoing frames (to the DS) based on the SSID (BSSID) of the received frame. MLD can also assign a virtual MLD ID to each SSID (or VLAN), but only one MLD MAC address and one MAC SAP to the DS. The constraint is that the AP of the virtual MLD cannot advertise different SSIDs. Otherwise, a non-AP MLD associated with the virtual MLD would receive frames from multiple VLANs. Therefore, it is possible to segment an MLD to map to two or more VLANs. However, the number of VLANs that can be supported is limited (maximum half the number of APs).

[0090] Figure 5A and Figure 5B An implementation of a network 500 with layer 1 virtualization without any interconnection with VLANs is illustrated in accordance with various embodiments. Figure 5AIn network 500, AP MLD 502 provides two virtual networks based on device type: one for regular MLDs and one for single-link MLDs and legacy STAs. AP MLD 502's three physical APs are divided into two groups. AP-1 504 (corresponding to BSSID-1.1 510) and AP-2 506 (corresponding to BSSID-1.2 512) advertise SSID: Multi-links and cater to multi-link non-AP MLDs, such as non-AP MLD-1 516. AP-3 508 (corresponding to BSSID-2 514) advertises SSID: Single-link and caters to legacy STAs and single-link MLDs (i.e., MLDs that can switch between multiple links but can only operate on one link at any given time), such as single-link non-AP MLD-2 518. Non-AP MLD-1 516 is associated with SSID: Multi-links, while single-link non-AP MLD-2 518 is associated with SSID: Single-link. Figure 5B An alternative view of three APs is shown: AP-1 504, AP-2 506, and AP-3 508 operate on links 1, 2, and 3 with link IDs 1, 2, and 3, respectively.

[0091] Figure 6A and Figure 6B 1 illustrates an implementation of a network 600 with layer 1 virtualization using a combination of physical APs and VAPs according to various embodiments. Figure 6AIn network 600, one physical AP and two sets of VAPs in the MLD are divided into three SSIDs. AP MLD 602 ​​includes AP-1 604, VAP-2 606, VAP-3 608, and VAP-4 610. VAP-5 612 is an independent AP. AP-1 604 (corresponding to BSSID-1 614) and VAP-2 606 (corresponding to BSSID-2.1 616) advertise the SSID: Staff. VAP-3 608 (corresponding to BSSID-2.2 618) and VAP-4 610 (corresponding to BSSID-3.1 620) advertise the SSID: Guest. The independent VAP-5 612 (corresponding to BSSID-3.2 622) advertises the SSID: IOT. SSID: Staff is mapped to VLAN 1 624, SSID: Guest is mapped to VLAN 2 626, and SSID: IOT is mapped to VLAN 3 628. In other words, AP MLD 602 ​​bridges wireless frames between the AP and the VLANs, mapping each SSID to the corresponding VLAN. Non-AP MLD-1 630 joins the network with SSID: Staff, and non-AP MLD-2 632 joins the network with SSID: Guest. STA-3 634 joins the network with SSID: IOT.

[0092] VAP-2 606 and VAP-3 608 are virtual APs of the same AP and form VAP Set 1. VAP-4 610 and VAP-5 612 are virtual APs of the same AP and form VAP Set 2. Additionally, AP-1 604 and VAP-2 606 form VAP MLD-1 (Virtual AP MLD-1), while VAP-3 608 and VAP-4 610 form VAP MLD-2. VAPs can be members of a co-hosted BSSID set or a multi-BSSID set. In this example, the VAPs are implemented as multiple BSSIDs. VAP-2 606 and VAP-3 608 are members of multi-BSSID set 1, which includes BSSID-2.1 616 and BSSID-2.2 618, while VAP-4 610 and VAP-5 612 are members of multi-BSSID set 2, which includes BSSID-3.1 620 and BSSID-3.2 622. Within these multi-BSSID sets, transmitting BSSIDs correspond to VAP-3 608 and VAP-5 612, while non-transmitting BSSIDs correspond to VAP-2 606 and VAP-4 610. AP-1 604, VAP-3 608, and VAP-5 612 transmit beacon frames. Even though multiple APs / VAPs can operate on the same link (frequency channel), different link IDs can be assigned to the APs / VAPs. Figure 6B An alternative view of five APs / VAPs is shown. AP-1 604 operates on link 3, VAP-2 606 and VAP-3 608 operate on link 2, and VAP-4 610 and VAP-5 612 operate on link 1. AP-1 604, VAP-2 606, VAP-3 608, and VAP-5 612 are assigned link IDs 1, 2, 3, and 4, respectively. Examples of MAC addresses for AP MLD 602 ​​and the five APs / VAPs are shown below:

[0093] -MLD MAC address = 0A-20;

[0094] -BSSID-1 (AP-1) = 0A-21;

[0095] -BSSID-2.1 (VAP-2) = 0D-21; BSSID-2.2 (VAP-3) = 0D-22;

[0096] -BSSID-3.1 (VAP-4) = 0E-21; BSSID-3.2 (VAP-5) = 0E-22;

[0097] Advantageously, it is possible to extend MLD by using VAPs and map to two or more VLANs with this embodiment of network 600. However, the number of VLANs that can be supported is low (maximum number of VLANs = number of physical APs).

[0098] As a further analysis, the implementation of network 600 is equivalent to logically extending one MLD into two virtual MLDs and one independent AP. During discovery, VAPs can advertise different SSIDs without any problems. For a multi-link setup, all APs (including VAPs) of the MLD advertise the same MLD address. However, different VAPs operate on different links (even if some of them operate on the same channel). In terms of security, different VAPs should have different group keys (GTK / IGTK). Regarding interconnection with VLANs, one VLAN ID is mapped to an SSID (and mapped to a virtual MLD). There is a single MLD MAC address and a MAC SAP to the DS. The virtual MLD ID can be used for faster conversion between VLAN IDs and SSIDs. The constraint is that the AP of the virtual MLD should not advertise different SSIDs. Otherwise, the non-AP MLD associated with the virtual MLD will receive frames from multiple VLANs. Therefore, it is possible to extend the MLD and map to two or more VLANs by using VAPs. However, the number of VLANs that can be supported is low, with a maximum of the number of physical APs. For example Figure 6A and Figure 6B Another point to note about this type of deployment, as shown in Figure 1, is that because VAPs belonging to the same VAP set (or co-hosted BSSID set or multi-BSSID set) are part of the same AP MLD, and because they cannot transmit and receive simultaneously, special coordination is required between the virtual MLDs for multilink transmission. For example, while AP1 604 and VAP2 606 are multilinking with non-AP MLD-1 in the Staff network, VAP3 608 cannot transmit simultaneously due to the shared hardware resources with VAP2 606, and only VAP4 610 can be used to transmit and receive frames to / from non-AP MLD-2 in the Guest network.

[0099] Under Layer 1 virtualization, each SSID is mapped to one or more VLANs. When a VLAN-tagged frame (e.g., tagged with VLAN 1) is received at the AP MLD's wired interface, the AP MLD must ensure that the frame is broadcast only on WLANs with SSIDs mapped to the VLAN whose ID is tagged in the received frame (e.g., WLANs with SSIDs mapped to VLAN 1). Similarly, when a frame destined for the DS is received on any wireless interface, the AP MLD must ensure that the correct VLAN ID is tagged to the outgoing wired frame based on the SSID. To do this, the AP MLD maintains a mapping of VLAN IDs to SSIDs and AP MAC addresses. An example of this mapping is shown in Table 1 below.

[0100]

[0101] Table 1

[0102] Figure 7 Figure 7 shows an example of a broadcast 802.3 frame 700 and an 802.11 frame 702 based on the mapping in Table 1. 802.3 frame 700 is transmitted from a router to an AP-MLD. The 802.1Q header of 802.3 frame 700 indicates VLAN 1 in VID field 706. According to Table 1, VLAN 1 is mapped to SSID: Staff. Therefore, the resulting 802.11 frame 702 can only be broadcast by an AP mapped to the SSID corresponding to the VLAN ID in the received Ethernet frame (i.e., in 802.3 frame 700). In this example, the received broadcast Ethernet packet will be transmitted by either AP1 or AP2 with SSID: Staff.

[0103] Since multiple SSIDs can share the same MAC-SAP in layer 1 virtualization, the MA-UNITDATA.request primitive needs to indicate the destination SSID (or alternatively the virtual MLD ID, if it exists), especially for broadcast data. An example of such a MAC data service primitive is shown below:

[0104] MA-UNITDATA.request(

[0105] source address,

[0106] destination address,

[0107] routing information,

[0108] data,

[0109] priority,

[0110] drop eligible,

[0111] service class,

[0112] station vector,

[0113] MSDU format,

[0114] SSID )

[0116] Based on the SSID field indicated in the MAC data service primitive, the broadcast data frame is transmitted only on the BSSID corresponding to the indicated SSID. Alternatively, a list of BSSIDs may be provided instead of SSIDs.

[0117] Layer 1 AP MLD can be implemented as a shared upper layer MAC (UMAC) structure without requiring complex virtualization technologies like a hypervisor. Figure 8 A diagram depicts an APMLD 800 with Layer 1 virtualization and a shared UMAC architecture, according to various embodiments. The shared UMAC 802 ensures proper translation between wired VLAN frames and wireless frames. The APs (AP-1 804, AP-2 806, AP-3 808, and AP-4 810) are tightly coupled, making information sharing easier. However, performance is impacted by the sharing of common resources (e.g., memory).

[0118] Under layer 2 virtualization, co-located APs are grouped into two or more AP groups to create multiple AP MLDs. Figure 9 A diagram depicts co-located APs grouped into two or more AP groups to create multiple AP MLDs for Layer 2 virtualization in accordance with various embodiments. In this diagram, co-located APs (AP1 902, AP2 904, and AP3 906) are used to create AP MLD1 908, AP MLD2 910, and VAPs 912. Each AP MLD is mapped to a unique SSID. Each SSID is mapped to one or more VLANs. There are multiple MAC-SAPs to the DS and multiple MAC addresses, one for each AP MLD or VAP. By using VAPs (up to 8 per physical AP), many MLDs can be created to support a large number of VLANs. Since APs / VAPs can be attached to different AP MLDs, link IDs can be assigned in two ways:

[0119] 1. Link IDs are local to the AP MLD, i.e., each AP MLD assigns a link ID to its affiliated AP, independent of other co-located AP MLDs.

[0120] 2. Link IDs are globally assigned to co-located AP MLDs so that link IDs are never repeated in a set of co-located AP MLDs.

[0121] Figure 10A and Figure 10B The diagram illustrates an implementation of a network 1000 with Layer 2 virtualization and multiple AP MLDs according to various embodiments. Three sets of VAPs are mapped to two MLDs and three SSIDs. AP MLD1 1002 includes VAP-1 1008 (corresponding to BSSID-1.1 1020), VAP-3 1012 (corresponding to BSSID-1.2 1022), and VAP-5 1016 (corresponding to BSSID-1.3 1024), and advertises the SSID: Staff. AP MLD2 1004 includes VAP-2 1010 (corresponding to BSSID-2.1 1026) and VAP-4 1014 (corresponding to BSSID-2.2 1028), and advertises the SSID: Guest. Standalone VAP-6 1018 corresponds to BSSID-3 1030 and advertises the SSID: IOT. Non-AP MLD-1 1032 is associated with SSID: Staff, non-AP MLD-2 1034 is associated with SSID: Guest, and STA-3 1036 is associated with SSID: IOT. In this example, the VAPs can be co-hosted BSSIDs or multiple BSSIDs. When a VAP is a member of a multiple BSSID set, the transmit BSSIDs correspond to VAP-1 1008, VAP-4 1014, and VAP-6 1018, such that each virtual network has at least one beacon frame; accordingly, VAP-1 1008, VAP-4 1014, and VAP-6 1018 transmit beacon frames.

[0122] Figure 10BAn alternative view of APs / VAPs is shown. VAP-1 1008 and VAP-2 1010 operate on link 3, VAP-3 1012 and VAP-4 1014 operate on link 2, and VAP-5 1016 and VAP-6 1018 operate on link 1. Because VAPs are affiliated with different AP MLDs, link IDs can be assigned in two ways. In the first approach, link IDs are local to the AP MLD. For example, VAP-1 1008, VAP-3 1012, and VAP-5 1016 are assigned link IDs 1, 2, and 3, respectively, by AP MLD1 1002, while VAP-2 1010 and VAP-4 1014 are assigned link IDs 1 and 2 by AP MLD2 1004. In the second approach, link IDs are globally assigned to co-located MLDs. For example, VAPs 1-5 are assigned link IDs 1-5, respectively. An example of MLD and the MAC addresses of the six VAPs is shown below:

[0123] -MLD-1 MAC address = 0A-20; MLD-2 MAC address = 0D-20; VAP-6 MAC address = 0D-32

[0124] -BSSID-1.1 (VAP-1) = 0A-21; BSSID-1.2 (VAP-3) = 0D-22; BSSID-1.3 (VAP-5) = 0A-23;

[0125] -BSSID-2.1 (VAP-2) = 0A-22; BSSID-2.2 (VAP-4) = 0D-21;

[0126] -BSSID-3 (VAP-6) = 0D-31;

[0127] As a further example, the implementation of network 1000 is equivalent to using VAPs to expand the group of co-located physical APs into multiple MLDs. During discovery, when the number of MLDs exceeds the number of physical APs, the multi-BSSID approach can face issues with advertising MLD information (e.g., MLD MAC addresses). MLD MAC address assignment and signaling efficiency may also be problematic. In a multi-link setup, non-AP MLDs should be able to easily discover APs or VAPs on other links of the MLD, especially if the VAPs are non-transmitting BSSIDs. For security, different VAPs should have different group keys (GTK / IGTK). Regarding interconnection with VLANs, a single VLAN ID is mapped to an SSID (and thus to a virtual MLD). Multiple MLD MAC addresses and multiple MAC SAPs exist for DSs. If a single SSID is mapped to a single MLD, then the VLAN ID can be mapped to the MLD MAC address. However, if there is only one physical connection to the DS, a single MLD MAC address is more appropriate. Therefore, using VAPs allows virtualization of MLDs to support multiple VLANs.

[0128] Figure 11A and Figure 11B 1 illustrates an implementation of a network 1100 with layer 2 virtualization using multiple AP MLDs with only physical APs in accordance with various embodiments. Figure 11A , the two sets of VAPs are mapped to two MLDs and two SSIDs. AP MLD1 1102 includes VAP-1 1106 and VAP-2 1108 and advertises the SSID: Staff. AP MLD2 includes VAP-3 1110 and VAP-4 1112 and advertises the SSID: Guest. Non-AP MLD-1 1114 is associated with the SSID: Staff, while non-AP MLD-2 1116 is associated with the SSID: Guest. Figure 11B An alternative view of VAPs is shown. VAPs 1-4 operate on links 1-4, respectively. Because VAPs are affiliated with different AP MLDs, link IDs can be assigned in two ways. In the first approach, link IDs are local to the AP MLD. For example, VAP-1 1106 and VAP-2 1108 are assigned link IDs 1 and 2, respectively, by AP MLD1 1102, while VAP-3 1110 and VAP-4 1112 are also assigned link IDs 1 and 2 by AP MLD2 1104. In the second approach, link IDs are globally assigned to co-located MLDs. For example, VAPs 1-4 are assigned link IDs 1-4, respectively.

[0129] Under Layer 2 virtualization, each SSID is mapped to one or more VLANs. When a VLAN-tagged frame is received at the AP MLD's wired interface, the AP MLD needs to ensure that the frame is broadcast only on WLANs with the SSID mapped to the VLAN ID tagged in the received frame. Similarly, when a frame destined for the DS is received on any wireless interface, the AP MLD needs to ensure that the correct VLAN ID is tagged to the outgoing wired frame, based on the SSID. In addition, the AP MLD needs to maintain a mapping of VLAN IDs to SSIDs and MLD / AP MAC addresses. The mapping based on network 1000 is shown in Table 2 below:

[0130]

[0131] Table 2

[0132] in addition, Figure 12 1200 and 802.3 frame 1202 based on the mapping in Table 2. 802.11 frames are broadcast only by APs affiliated with the AP MLD that maps to the SSID corresponding to the VLAN ID in the received Ethernet frame. In this example, broadcast 802.11 packets received by VAP-3 1012 and VAP-4 1014 with SSID: Guest are tagged with an IEEE 802.1Q tag with VLAN ID = VLAN2 (as shown in VID field 1204 of 802.3 frame 1202) before being forwarded to the Ethernet interface.

[0133] Layer 2 AP MLD can also be implemented without using hypervisor virtualization when only physical APs or only a few VAPs are involved. Figure 13 Diagram 1300 depicts Layer 2 AP MLD1 1302 and AP MLD2 1304 without hypervisor virtualization, according to various embodiments. AP MLD1 1302 includes AP-1 1306 and AP-2 1308, while AP MLD2 1304 includes AP-3 1310 and AP-4 1312. In this embodiment, each AP MLD1 1302 and AP MLD2 1304 appears as a distinct entity with its own MAC-SAP to DS. Advantageously, due to the one-to-one mapping between AP MLDs and VLANs, the conversion of VLAN frames and radio frames is simple.

[0134] When many VAPs are involved, Layer 2 AP MLD may need to be implemented using hypervisor virtualization. Figure 14Diagram 1400 depicts Layer 2 AP MLD1 1402, AP MLD2 1404, and VAP-6 1406 with hypervisor virtualization according to various embodiments. AP MLD1 1402 includes VAP-1 1408, VAP-3 1412, and VAP-5 1416, while AP MLD2 1404 includes VAP-2 1410 and VAP-4 1414. Virtualization layer 1424 is responsible for ensuring proper binding of virtual APs to physical APs AP-1 1418, AP-2 1420, and AP-3 1422. Each AP MLD1 1402, AP MLD2 1404, and VAP-6 1406 appears as a distinct entity with its own MAC-SAP to the DS. Advantageously, due to the one-to-one mapping between AP MLDs and VLANs, conversion between VLAN frames and radio frames is simple.

[0135] A unified signaling that can support different system architectures and different uses is proposed. Figure 15 A diagram of a multilink element 1500 configured for unified signaling according to various embodiments is depicted. The multilink element 1500 includes an "element ID" field, a "length" field, an "element ID extension" field, a "type" field 1502, a "common information" field 1504, and one or more "per-link information" fields 1506. The "type" field 1502 is set to discovery when used by an AP MLD to advertise link information, or to multilink setup when used by a non-AP MLD during multilink setup. Examples of various "type" field values ​​that may be implemented are shown in Table 3 below:

[0136]

[0137] Table 3

[0138] The "Common Information" field 1504 includes a "Common Control" field 1508, a "Host Link ID" field 1510, an "MLD MAC Address" field, a "Multi-Link Capability" field, and an "SSID" field. The "Common Control" field 1508 includes a "Host Link ID Present" field, an "MLD MAC Address Present" field, a "Multi-Link Capability Present" field, a "SSID Present" field, and a "Number of Per-Link Information" field 1512. The "Number of Per-Link Information" field 1512 indicates how many "Per-Link Information" fields are present. A value of 0 indicates none. The "Common Information" field 1504 carries information about MLD that is common across all links, such as the MLD MAC address, multi-link capability, and a common SSID. The "Host Link ID" field 1508 indicates the link ID assigned to the link (i.e., the host link) on which the multi-link element 1500 is transmitting. If all links of an AP MLD advertise the same SSID, then the MLD-level SSID can be defined and indicated in the "Common Information" field, and the "SSID" field can be omitted in the "Per-Link Information" field. In such a case, the beacon frame carries the SSID for legacy devices, which can be different from the MLD-level SSID defined for non-AP MLDs.

[0139] The "Per-Link Information" field 1506 includes a "Presence Bitmap" field 1512, a "Link ID" field, a "Capability Information" field, a "Listen Interval" field, an "AID" field, an "SSID" field, a "BSSID / MAC Address" field, a "Untransmitted BSSID Information" field 1514, an "Operating Channel" field 1516, and zero or more "Optional Sub-Element" fields. The "Presence Bitmap" field 1512 includes a "Capability Information Present" field, a "Listen Interval Present" field, an "SSID Present" field, a "BSSID / MAC Address Present" field, a "Untransmitted BSSID Information Present" field, and an "Operating Channel Present" field. The "Untransmitted BSSID Information" field includes a "Transmitted BSSID" field 1518, a "MaxBSSID Indicator" field 1520, and a "BSSID Index" field 1522. The "Operating Channel" field 1516 includes an "Operation Category" field and a "Channel Number" field. When present, each "Per-Link Information" field identifies one of the MLD links. The "Per-Link Information" field typically does not carry information about the host link (the link on which frames carrying multilink elements are transmitted, or the link on which the AP / VAP associated with the multilink element operates). If the link corresponds to a non-transmitted BSSID, the "Non-Transmitted BSSID Information" field 1518 provides the identity of the transmitted BSSID. If different from the host link information, other sub-elements related to the link (e.g., EHT Operation element, EDCA (Enhanced Distributed Channel Access) parameter set element, etc.) may be carried.

[0140] As a variation, the "Common Control" field can be placed outside the "Common Information" field, immediately following the "Type" field, or even replacing the "Type" field. In this case, the "Common Control" field can also indicate whether the ML element carries the "Common Information" field or the "Per-Link Information" field. In addition to fields, each Per-Link Information field can also be a sub-element. Furthermore, instead of the full SSID, a 4-octet short / compressed SSID (with a 32-bit CRC calculated over the SSID) can be used in the "Common Information" and "Per-Link Information" fields. The Multilink element can also carry a non-inherited element to indicate which elements carried in the host frame are not inherited by the link information. The concept of non-inheritance can be useful when the reporting link / AP does not inherit a certain element. For example, if the reporting AP (i.e., the AP corresponding to the host link / element) supports UORA (Ultra-Long Response Time Random Access), while the reporting AP (i.e., the AP corresponding to the per-link information) does not support UORA, the non-inherited element signals this information—i.e., non-inheritance.

[0141] Therefore, the link ID of the host link is indicated in the "Host Link ID" field 1508 of the multi-link element 1500. Advantageously, if the link of the MLD is a non-transmitted BSSID (i.e., does not transmit beacons), then the "Per Link Information" field 1506 in the multi-link element 1500 should provide information corresponding to the transmitted BSSID to help non-AP MLDs easily find the beacons.

[0142] Aside from the always-present "Link ID" field, the presence of other fields in the "Per-Link Information" field depends on the usage scenario. For example, if used during discovery, the "Capability Information," "Listen Interval," and "AID" fields may be omitted. Similarly, when used during multi-link setup, the "Operating Channel" field and the "Untransmitted BSSID Information" field may be omitted. The "Listen Interval" field is only present in Association Request frames transmitted by non-AP MLDs, while the "AID" field is only present in Association Response frames transmitted by APMLDs. If the SSID associated with a link is different from the SSID indicated in the Host frame or the "Common Information" field, the "SSID" field may be included in the "Per-Link Information" field 1506. The "BSSID / MAC Address" field carries the BSSID corresponding to the link indicated in the Association Response frame, while it carries the MAC address of that link in the Association Request frame. It will be appreciated that other names may also be used, for example, "host link" may be referred to as "transmitted link"; "host link ID" may also be referred to as "transmitted link ID"; "per-link information" may be referred to as "AP information" or "per-STA information", etc.

[0143] Several embodiments are possible for implementing the techniques discussed above. In a first embodiment, beacon and probe response frames carry a Multi-Link Element (ML element), which carries MLD common information (e.g., MLD MAC address) as well as information about the MLD's other links. The ML element identifies the link ID assigned to the host link. The ML element may not carry host link information. The ML element also carries basic information (link ID, SSID, BSSID, operating channel, etc.) about the other links of the AP MLD to which the AP transmitting the frame is affiliated. Information common to the host link may not be repeated, but rather inherited from information carried in the frame or from the non-transmitting BSSID profile (in the Multi-BSSID element) carrying the Multi-Link Element. If the MLD's link corresponds to a non-transmitting BSSID, the link information in the ML element also provides the information necessary to identify the corresponding transmitted BSSID. Advantageously, the ML element has low overhead but provides sufficient information to help non-AP MLDs quickly locate more information about the link of interest before deciding whether to associate with this AP MLD.

[0144] In a second embodiment, the host frame also carries an RNR element and / or a Neighbor Report element, which carries information about some of the other APs (co-located or not). These elements also indicate the MLD MAC address and link ID associated with the AP affiliated with the MLD. The ML element carries minimal information (link ID) for the link already included in the RNR / Neighbor Report element, and carries full / complete information for links other than the host link (link ID, SSID, BSSID, operating channel, TBTT (target beacon transmission time), etc.). Advantageously, a non-AP MLD can receive information for all APs hosted on the same device in a single frame.

[0145] In a third embodiment, the host frame carries an RNR element or Neighbor Report element, which carries information about all co-located APs. The ML element carries minimal information about other links (Link ID, BSSID), which is used to reference the RNR or Neighbor Report element for more information. This implementation benefits from not modifying the RNR or Neighbor Report element for legacy compatibility. Furthermore, while the ML element has very low overhead, it relies on the inclusion of other Neighbor Report elements to provide further details about other MLD links.

[0146] In the fourth embodiment, a new Neighbor MLD Report element is defined to make neighbor MLD notification more efficient. The Neighbor MLD element can be used to carry information about both co-located and non-co-located MLDs. Advantageously, non-AP STAs can obtain MLD information from a single report element. However, if RNR or Neighbor Report elements are also carried for legacy STAs, information duplication may occur.

[0147] Figure 16 A simplified diagram of a beacon / broadcast probe response frame 1600 configured for Layer 1 virtualization with all physical APs according to a first embodiment is depicted. Beacon / broadcast probe response frame 1600 can be implemented as either a beacon frame or a broadcast probe response frame. It carries a multilink element 1604, which carries MLD common information (e.g., the MLD MAC address) as well as information about other links of the MLD. ML element 1604 identifies the host link ID, i.e., the link ID assigned to the host link (the link on which the frame is transmitted). ML element 1604 does not carry host link information; instead, the host link ID is used to refer to the host link information 1602 carried by beacon / broadcast probe response frame 1600.

[0148] The ML element also carries basic information (link ID, SSID, BSSID, operating channel, etc.) for the other links of the AP MLD to which the AP transmitting the frame is attached. Information identical to the host link MUST NOT be repeated. This is called inheritance, meaning the information already exists in either the host frame / element or the "common information" field. The host element refers to a multi-BSSID element that carries more information about the link referenced by the link ID. Fields from the multi-link element 1604 are not repeated in the "per-link information" field unless the information is different for that link, in which case the information is also present in the "per-link information" field. It should be appreciated that there may be some exceptions for some fields, such as the SSID, which may be repeated for faster discovery. Additionally, if the SSID associated with a link is different from the SSID indicated in the host frame or the common information field, the SSID may be included in the "per-link information" field. The non-AP MLD uses the information of other links in the ML element 1604 to gather complete information of the APs on the link (e.g., by scanning the link, or by referencing RNR or Neighbor Report elements carried in the host frame) and can associate with APs advertising the same SSID.

[0149] Figure 17 The first embodiment is described as follows Figure 4A and Figure 4B, which is an illustration of a beacon frame 1700 transmitted by AP-1 404 of network 400 shown in FIG. Beacon frame 1700 indicates the BSSID MAC address 1702 of AP-1 404 as "0A-21" and the associated SSID 1704 as "Staff." Multilink element 1706 indicates type field 1708 as "Discovery." Under common information, host link ID 1710 is set to "1," indicating that link ID 1 is assigned to the host link; and MLD MAC address 1712 is indicated as "0A-20." Multilink element 1706 also includes three "Per-Link Information" fields 1714 representing AP-2, AP-3, and AP-4. Each "Per-Link Information" field provides information such as the link ID, SSID, BSSID, and operating channel for the represented / reported AP. It should be appreciated that although the "Common Control" field and the "Presence Bitmap" field are not described in the ML element 1706, the ML element format is the same as Figure 15 The same as the ML element 1500 in.

[0150] Figure 18 A simplified diagram of a beacon / probe response frame 1800 configured for Layer 1 virtualization using VAPs according to a first embodiment is depicted. Beacon / probe response frame 1800 includes host link information 1802, a multi-BSSID element 1804, and a multi-link element 1806 (in the same format as ML element 1500). In this example, preferably, at least one BSSID in the virtual MLD transmits a beacon frame (i.e., it is a transmitting BSSID), so that each SSID has its own beacon frame. If a link of the MLD corresponds to a non-transmitting BSSID, the link information in ML element 1806 also provides information (such as non-transmitted BSSID information 1808) necessary to identify the transmitted BSSID corresponding to the non-transmitting BSSID, for example, in an RNR element or neighbor report element carried in a host frame, or in a beacon / probe response frame of a different VAP, in addition to or in addition to the BSSID. The transmitted BSSID field 1810 identifies the AP that transmitted the beacon frame 1800, which carries the untransmitted BSSID profile 1816, while the "maximum BSSID indicator" field 1812 and the "BSSID index" field 1814 can be used with the "transmitted BSSID" field 1810 to calculate the untransmitted BSSID.

[0151] If the non-transmitted BSSID is attached to an MLD, then non-transmitted BSSID profile 1816 (within multi-BSSID element 1804) may also carry another ML element 1818 as an optional child element. If the link corresponds to a physical AP or a co-hosted AP that transmits its own beacon frame, the per-link information identifies the BSSID of the AP. Additionally, if ML element 1818 is carried in non-transmitted BSSID profile 1816 within multi-BSSID element 1804, the "Host Link ID" field within ML element 1818 indicates the link ID assigned to the link on which the AP corresponding to the non-transmitted BSSID operates (and not the link on which the beacon frame carrying the multi-BSSID element was transmitted). The AP may also split the non-transmitted BSSID profile across multiple BSSID elements within the frame. If the transmitted BSSID indicated by the "Transmitted BSSID" field 1810 in the non-transmitted BSSID information 1808 matches the BSSID of the frame, the non-AP MLD may use the non-transmitted BSSID information 1818 to obtain complete information about the link corresponding to the non-transmitted BSSID from the multiple BSSID elements 1804 carried in the same frame. Otherwise, the non-AP MLD may scan the link to collect complete information about the link from the beacon / probe response frames from the AP corresponding to the transmitted BSSID.

[0152] The "SSID" field in the multilink element can be replaced with a "Short SSID" field. The short SSID is a 32-bit CRC calculated over the SSID. The "Operating Channel" field indicates the operating channel of the link and consists of an "Operating Class" field and a "Channel Number" field, which together uniquely identify the channel on which the link operates.

[0153] Figure 19 The first embodiment is described as follows Figure 6A and Figure 6B6 shows an illustration of a beacon frame transmitted by AP-1 604 of network 600 shown in FIG. Beacon frame 1900 indicates the BSSID MAC address 1902 of AP-1 604 as "0A-21" and the associated SSID 1904 as "Staff." Multilink element 1906 indicates a "Type" field 1908 as "Discovery." Under common information, host link ID 1910 is indicated as "1," and MLD MAC address 1912 is indicated as "0A-20." Multilink element 1906 also includes three "Per-Link Information" fields 1914, 1916, and 1918, representing VAP-2 606, VAP-3 608, and VAP-4 610, respectively. The "Per-Link Information" field 1914 provides information for the represented VAP-2 606, such as the link ID (indicated as "2"), the SSID (indicated as "Staff"), untransmitted BSSID information, and the operating channel. The "Per-Link Information" field 1916 provides information for the represented VAP-3 608, such as the link ID (indicated as "3"), the SSID (indicated as "Guest"), the BSSID (indicated as 0E-21), and the operating channel. The "Per-Link Information" field 1918 provides information for the represented VAP-4 610, such as the link ID (indicated as "4"), the SSID (indicated as "Guest"), untransmitted BSSID information 1920, and the operating channel. The non-transmitted BSSID information 1920 provides information for VAP-5 612 (because VAP-4 610 and VAP-5 612 are virtual APs of the same AP and form VAP Set 2), such as the transmitted BSSID (indicated as 0E-22), the maximum BSSID indicator, and the BSSID index. It should be appreciated that although the "common control" field and the "presence bitmap" field are not illustrated in the ML element 1906, the ML element format is the same as Figure 15 The same as the ML element 1500 in.

[0154] Figure 20 The first embodiment is described as follows Figure 6A and Figure 6B1 is an illustration of a beacon frame 2000 transmitted by VAP-3 608 of network 600. Beacon frame 2000 indicates the BSSID MAC address 2002 of VAP-3 608 as "0D-22" and the associated SSID 2004 as "Guest." Multilink element 2006 indicates the "Type" field 2008 as "Discovery." Under common information, host link ID 2010 is set to "3," indicating that the link ID assigned to the host link is 3, and MLD MAC address 2012 is indicated as "0A-20." Multilink element 2006 also includes three "Per-Link Information" fields 2014, 2016, and 2018, representing AP-1 604, VAP-2 606, and VAP-4 610, respectively. The "Per-Link Information" field 2014 provides information for the indicated AP-1 604, such as its link ID (indicated as "1"), SSID (indicated as "Staff"), BSSID (indicated as "0A-21"), and operating channel. The "Per-Link Information" field 2016 provides information for the indicated VAP-2 606, such as its link ID (indicated as "2"), SSID (indicated as "Staff"), untransmitted BSSID information 2022, and operating channel. The "Per-Link Information" field 2018 provides information for the indicated VAP-4 61, such as its link ID (indicated as "4"), SSID (indicated as "Guest"), untransmitted BSSID information 2020, and operating channel. Untransmitted BSSID information 2020 provides information for VAP-5 612, i.e., it points to the untransmitted BSSID of a different VAP set.

[0155] Beacon frame 2000 also includes a "Multi-BSSID Element" field 2024, which provides information for the non-transmitting BSSID VAP-2 606 (because VAP-2 606 and VAP-3 608 are virtual APs of the same AP and form VAP Set 1). "Multi-BSSID Element" field 2024 includes the non-transmitting BSSID profile for VAP-2 606, including at least information about the SSID (indicated as "Staff"), as well as another multilink element 2026 carrying information about AP MLD1, because VAP-2 corresponds to and is associated with the non-transmitting BSSID profile. Non-transmitting BSSID information 2022 points to this non-transmitting BSSID profile for VAP-2 606 (i.e., the non-transmitting BSSID profile for the same VAP Set). Since the MLD information is already carried in the host frame 2000, the ML element 2026 carried in the untransmitted BSSID profile carries only the MLD MAC address (indicated as "0A-20") in the common information field, which can be used to reference back to the ML element 2006 in the host frame. It should be appreciated that although the "common control" field and the "presence bitmap" field are not described in the ML elements 2006 and 2026, the ML element format is the same as Figure 15 The same as the ML element 1500 in.

[0156] Figure 21 The first embodiment is described as follows Figure 6A and Figure 6B Figure 2 illustrates a beacon frame 2100 transmitted by VAP-5 612 of the illustrated network. Beacon frame 2100 indicates the BSSID MAC address 2102 of VAP-5 604 as "0E-22" and the associated SSID 2104 as "IOT." A multi-BSSID element 2106 provides information for the non-transmitted BSSID VAP-4 610 (because VAP-4 610 and VAP-5 612 are virtual APs of the same AP and form VAP Set 1). The "Multi-BSSID Element" field 2106 includes the non-transmitted BSSID profile for VAP-4 610, including at least SSID information (indicated as "Guest") and a multilink element 2108. Generally speaking, a VAP's non-transmitted BSSID profile, as part of the AP Multi-Link Level Detection (MLD) protocol, also carries a multilink element, which carries MLD-related information. In this case, multilink element 2108 carries MLD-related information for AP MLD 602.

[0157] Under Layer 2 virtualization, Beacon and Probe Response frames have the same format as Layer 1, except that the "SSID" field is not advertised in the individual Per-Link Information fields because all VAPs of an AP MLD advertise the same SSID. The "SSID" field may be advertised in the "Common Information" field of the Multilink element, or it may be skipped entirely if the value is the same as the SSID advertised by the host Beacon or Probe Response frame. In Layer 2 virtualization, VAPs for the same physical AP cannot be in the same MLD, so the untransmitted BSSID information in the "Per-Link Information" field is not found in the Multi-BSSID element of the host frame, but must be recovered from the RNR or Neighbor Report element carried in the host frame, or from the Multi-BSSID elements carried in the Beacon or Probe Response frames of other APs. For example, in Figure 22 , in the case of the beacon / probe response frame 2200 for BSSID1, the untransmitted BSSID information in the "Link 2 Information" field 2204 cannot be found in the Multi-BSSID element 2202 of the host frame 2200, but must be recovered from the Multi-BSSID element 2208 carried in the beacon / probe response frame 2206 for BSSID2. The "Transmitted BSSID" field in the untransmitted BSSID information points to the beacon frame 2206 for BSSID2, and the BSSID index is used to locate the untransmitted BSSID profile in the Multi-BSSID element carried in the beacon frame 2206.

[0158] Figure 23 The first embodiment is described as follows Figure 10A and Figure 10B, which is an illustration of a beacon frame 2300 transmitted by VAP-1 1008 of network 1000. Beacon frame 2300 indicates the BSSID MAC address 2302 of VAP-1 1008 as "0A-21" and the associated SSID 2304 as "Staff." Multilink element 2306 indicates the "Type" field 2308 as "Discovery." Under common information, host link ID 2310 is indicated as "1" and MLD MAC address 2312 is indicated as "0A-20" (i.e., the MAC address of AP MLD1 1002). Multilink element 2306 also includes two "Per-Link Information" fields 2314 and 2316, representing VAP-3 1012 and VAP-5 1016, respectively. The "Per Link Information" field 2314 provides information for the represented VAP-3 1012, such as a link ID (indicated as "2"), operating channels, and untransmitted BSSID information 2318. The "Per Link Information" field 2316 provides information for the represented VAP-5 1016, such as a link ID (indicated as "3"), operating channels, and untransmitted BSSID information 2320. The untransmitted BSSID information 2320 provides information for the VAP-6 1018, such as a transmitted BSSID (indicated as "0D-31"), a maximum BSSID indicator, and a BSSID index.

[0159] Beacon frame 2300 also includes a multi-BSSID element 2322, which provides information for the untransmitted BSSID VAP-2 1010 (because VAP-1 1008 and VAP-2 1010 form VAP Set 1). Multi-BSSID element 2322 includes the untransmitted BSSID Profile 1 for VAP-2 1010, including at least information about the SSID (indicated as "Guest"), and another multi-link element 2324. Multi-link element 2324 indicates "Type" field 2326 as "Discovery." Under common information, host link ID 2328 is set to "1" and indicates the link ID assigned to the host link on which beacon frame 2300 is transmitted; and MLD MAC address 2330 is indicated as "0D-20" (i.e., the MAC address of AP MLD2 1004). The multilink element 2324 also includes a "per link information" field 2332 representing the VAP-4 1014, thereby providing information about the represented VAP-4 1014, such as the link ID (indicated as "2"), the operating channel, and the BSSID (indicated as 0D-21). It should be appreciated that although the "common control" field and the "presence bitmap" field are not described in the ML elements 2306 and 2324, the ML element format is the same as Figure 15 The same as the ML element 1500 in.

[0160] It should be noted that in the ML element 2324 carried within the non-transmitted BSSID profile 1 of the multi-BSSID element 2322 in the beacon frame 2300 transmitted by VAP-1 1008, the "Host Link ID" field indicates that link ID (1) is assigned to the VAP corresponding to the non-transmitted BSSID profile 1 (i.e., VAP-2 1010). In this example, the link ID happens to be the same as the link ID (1) assigned to the VAP that transmitted the beacon frame 2300, but if global link ID assignment is used instead of local link ID assignment, then they will be different. Moreover, since all links of AP MLD2 advertise the same SSID, an MLD-level SSID can be defined for AP MLD2, and the "SSID" field can be omitted from the "Per Link Information" field of the ML element 2324.

[0161] Figure 24 The first embodiment is described as follows Figure 10A and Figure 10B , which is an illustration of a beacon frame 2400 transmitted by VAP-4 1014 of network 1000. Beacon frame 2400 indicates the BSSID MAC address 2402 of VAP-4 1014 as "0D-21" and the associated SSID 2404 as "Guest." Multilink element 2406 indicates the "Type" field 2408 as "Discovery." Under common information, host link ID 2410 is indicated as "2" and MLD MAC address 2412 is indicated as "0D-20." Multilink element 2406 also includes a "Per-Link Information" field 2414 representing VAP-2 1010. Per-Link Information field 2414 provides information about the represented VAP-2 1010, such as its link ID (indicated as "1"), operating channel, and untransmitted BSSID information 2416. The non-transmitted BSSID information 2416 provides information of the VAP-1 1008, such as the transmitted BSSID (indicated as 0A-21), the maximum BSSID indicator, and the BSSID index.

[0162] The beacon frame 2400 also includes a multi-BSSID element 2418, which provides information for the untransmitted BSSID VAP-3 1012 (because VAP-3 1012 and VAP-4 1014 form a VAP set). The multi-BSSID element 2418 includes the untransmitted BSSID Profile 1 for VAP-3 1012, including at least the SSID information (indicated as "Staff"), and another multi-link element 2420 that carries the MLD MAC address of AP MLD1 1002 in its common information field. It should be appreciated that although the "common control" field and the "presence bitmap" field are not illustrated in the ML elements 2406 and 2420, the ML element format is the same as the ML element format. Figure 15 The same as the ML element 1500 in.

[0163] Figure 25 The first embodiment is described as follows Figure 10A and Figure 10B , which is an illustration of a beacon frame 2500 transmitted by VAP-6 1018 of network 1000. Beacon frame 2500 indicates the BSSID MAC address 2502 of VAP-6 1018 as "0D-31" and the associated SSID 2504 as "IOT." Beacon frame 2500 also includes a multi-BSSID element 2506 that provides information for the untransmitted BSSID VAP-5 1016 (because VAP-5 1016 and VAP-6 1018 form a VAP set). Multi-BSSID element 2506 includes the untransmitted BSSID Profile 1 for VAP-5 1016, including at least information for the SSID (indicated as "Staff"), and another multi-link element 2508 that carries the MLD MAC address of AP MLD1 1002 in its common information field.

[0164] A non-AP MLD can request complete information about other links of the AP MLD by sending a probe request frame on any link of the AP MLD. Figure 26 The first embodiment describes the transmission of the non-AP MLD to the Figure 10A and Figure 10B FIGURE 2 illustrates a probe request frame 2600 for VAP-1 1008 of network 1000 shown in FIGURE 2. Probe request frame 2600 includes a "BSSID" field 2602 indicated as "A-21," i.e., the MAC address of VAP-1 1008, a wildcard SSID 2604, and a multilink element 2606. Multilink element 2606 indicates a "Type" field 2608 as "Discovery." Under common information, the MLD MAC address 2610 is indicated as "10-20" and signals the AP MLD for which information is desired. Multilink element 2606 also includes two "Per-Link Information" fields 2612 and 2614, indicating link ID 2 and link ID 3, respectively. In other words, multilink element 2606 indicates the AP MLD and the links for which complete information is desired. The "Per-Link Information" field indicates additional links for which further information is desired (i.e., in addition to the link on which the frame was transmitted). If information for all links of the AP MLD is desired, the "Per Link Information" field can be omitted.

[0165] In response to the probe request frame 2600, the AP MLD sends a unicast probe response frame 2700, which carries complete information about the requested links (ie, link IDs 1, 2, and 3), as shown in FIG. Figure 27As shown in FIG. , a probe response frame 2700 is transmitted from VAP-1 1008 to the non-AP MLD that transmitted the probe request frame 2600. The probe response frame 2700 indicates the BSSID MAC address 2702 of VAP-1 1008 as "0A-21" and the associated SSID 2704 as "Staff." The multilink element 2706 indicates the "Type" field 2708 as "Discovery." Under common information, the host link ID 2710 is indicated as "1," and the MLD MAC address 2712 is indicated as "0A-20." The multilink element 2706 also includes two "Per-Link Information" fields 2714 and 2716, indicating VAP-3 1012 and VAP-5 1016, respectively. The "Per-Link Information" field 2714 provides information for the indicated VAP-3 1012, such as the link ID (indicated as "2"), operating channel, BSSID, operating parameters, and EDCA parameter set. The "Per-Link Information" field 2716 provides information for the indicated VAP-5 1016, such as the link ID (indicated as "3"), operating channel, BSSID, operating parameters, and EDCA parameter set. In other words, the multi-link element 2706 includes complete information for the requested links, including those corresponding to the BSSIDs that were not transmitted.

[0166] The probe response frame 2700 also includes a multi-BSSID element 2718 that provides information for the untransmitted BSSID VAP-2 1010 (because VAP-1 1008 and VAP-2 1010 form a VAP set). The multi-BSSID element 2718 includes the untransmitted BSSID Profile 1 for VAP-2 1010, including at least the SSID information (indicated as "Guest"), and another multi-link element 2720 that carries the MLD MAC address of AP MLD2 1004 in its common information field. It should be appreciated that although the "common control" field and the "presence bitmap" field are not illustrated in the ML elements 2706 and 2720, the ML element format is the same as the ML element format. Figure 15 Instead of unicasting the probe response frame, a broadcast probe response frame can also be used if multiple probe requests are received almost simultaneously or if it is close to the TBTT, and the beacon frame can carry full information instead of the probe response frame.

[0167] In a second embodiment, beacon and probe response frames may carry RNR elements and / or Neighbor Report elements that carry information about other APs (co-located or not). These elements also indicate the MLD MAC address and link ID associated with the AP attached to the MLD. In addition, untransmitted BSSIDs whose profiles are included in multiple BSSID elements in the same frame are not included. Figure 28As can be seen in the beacon / probe response frame 2800, the multi-link element 2802 carries the minimum information of the link included in the RNR / neighbor report element (link ID) and carries basic / complete information of other links except the host link (link ID, SSID, BSSID, operating channel, TBTT, etc.).

[0168] by Figure 10A Taking network 1000 as an example, in a beacon frame transmitted by VAP-1 1008, if VAP-2 1010 and VAP-3 1012 are non-transmitted BSSIDs, information about VAP-4 1014, VAP-5 1016, and VAP-6 1018 is carried in a Reduced Neighbor Report element, while a Multilink element carries full information about VAP-3 1012 and minimal information about VAP-5 1016. However, if all VAPs are co-hosted APs that transmit their own beacons, they can also be included in the Reduced Neighbor Report element. Advantageously, non-AP MLD can receive information for all APs hosted on the same device from a single frame.

[0169] In the example, Figure 29 The neighbor report element 2900 shown in FIG can be used to provide information of an AP or VAP, which may include a multilink element 2902 as an optional sub-element. In this case, the neighbor report element 2900 provides Figure 10A The multilink element 2902 indicates the information of VAP-2 1010 in the multilink element, and is affiliated with AP MLD2 1004. The BSSID corresponding to VAP-2 is indicated as "0A-22." The multilink element 2902 indicates the AP MLD and link ID to which this AP (VAP-2) is affiliated. For example, the multilink element 2902 indicates the "Type" field 2904 as "Discovery." Under the common information, the MLD MAC address 2906 is indicated as "0D-20," i.e., the MLD MAC address of AP MLD2 1004. The multilink element 2902 also includes a "Per-Link Information" field 2908 that indicates VAP-2 and provides information about the indicated VAP-2, such as the link ID (indicated as "1").

[0170] In the example, Figure 30 The simplified neighbor report element 3000 shown in FIG can be used to provide information for multiple APs or VAPs. In this case, the simplified neighbor report element 3000 is Figure 10AVAP-2 1010 in the RNR element provides information and is attached to AP MLD2 1004. The "TBTT Information Set" field 3002 indicates VAP-2's BSSID and VAP-2's short SSID-2 as "32-CRC (Guest)." Two additional fields have been added to the "TBTT Information Set" field 3002. Newly added fields 3004 and 3006 indicate the AP MLD MAC address and link ID, respectively, to which this AP (VAP-2) is attached. The "TBBT Information Field Type" subfield 3008, either by itself or in conjunction with the "TBTT Information Length" subfield 3010 of the RNR element, indicates the presence of additional MLD information. For example, if the "TBBT Information Field Type" field is set to a value other than 0, it indicates that the TBTT information set carries MLD information. For example, if it is set to 1, the link ID field is carried, while if it is set to 2, both the link ID and the MLD MAC address are carried. Alternatively, if "TBTT Information Length" is set to 13, it carries the link ID field, if it is set to 18, it carries the MLD MAC address, and if it is set to 19, it carries both the link ID and the MLD MAC address.

[0171] In a third embodiment, beacon and probe response frames carry multilink elements, which carry MLD common information (e.g., MLD MAC address) and information about other links of the MLD. Host frames carry RNR elements or neighbor report elements, which carry information about all co-located APs. Link IDs are assigned globally to all co-located MLDs. Figure 31 As shown in the Beacon / Probe Response frame 3100, the Multilink Element 3104 carries minimal information about the other links (Link ID, BSSID). This information is used to reference the RNR or Neighbor Report Element 3102 for more information. Advantageously, the RNR or Neighbor Report Element is not modified for legacy compatibility. The BSSID is used to link the information in the RNR or Neighbor Report Element to the Multilink Element. This is because the RNR Element always carries the BSSID of the reported AP. A non-AP MLD can use the Multilink Element and the information in the RNR or Neighbor Report Element to initiate multilink setup without having to scan other links to gather complete link information.

[0172] Figure 32 The third embodiment is described as follows Figure 10A and Figure 10BFigure 3200 illustrates a beacon frame transmitted by VAP-1 1008 of network 1000. In this example, link ID assignment is global for co-located AP MLDs; that is, link IDs for co-located MLDs are unique. For example, AP MLD 1 has link IDs of 1 (VAP-1), 2 (VAP-3), and 3 (VAP-5); and AP MLD 2 has link IDs of 4 (VAP-2) and 5 (VAP-4). Beacon frame 3200 indicates VAP-1 1008's BSSID MAC address 3202 as "0A-21" and its associated SSID 3204 as "Staff." Multilink element 3206 carries information about the AP MLD to which VAP-1 1008 is affiliated, namely, AP MLD1 1002. Multilink element 3206 indicates "Type" field 3208 as "Discovery." Under the common information, host link ID 3210 is set to "1," indicating that VAP-1 1008 is operating on the link assigned link ID 1, and MLD MAC address 3212 is indicated as "0A-20." Multi-link element 3206 also includes two "per-link information" fields 3214 and 3216, indicating the other APs affiliated with AP MLD1 1002 (i.e., VAP-3 1012 and VAP-5 1016, respectively). Per-link information field 3214 provides information for the indicated VAP-3 1012, such as its link ID (indicated as "2") and BSSID (indicated as "0D-22"). Per-link information field 3216 provides information for the indicated VAP-5 1016, such as its link ID (indicated as "3") and BSSID (indicated as "0A-23").

[0173] Beacon frame 3200 transmitted by VAP-1 1008 also includes a multi-BSSID element 3218, which provides information for the untransmitted BSSID VAP-2 1010 (because VAP-1 1008 and VAP-2 1010 form a multi-BSSID set and VAP-1 1008 is the transmitting BSSID for this multi-BSSID set). Multi-BSSID element 3218 includes information for the untransmitted BSSID Profile 1 for VAP-2 1010, including at least the SSID (indicated as "Guest"), and another multi-link element 3220 that provides information for the AP MLD to which VAP-2 is attached (i.e., APMLD2 1004). Multi-link element 3220 indicates "Type" field 3222 as "Discovery." Under the common information, the host link ID 3224 is set to "4", indicating that the link on which VAP-2 operates is assigned link ID 4, and the MLD MAC address 3226 is indicated as "0D-20". The multi-link element 3220 also includes a "per-link information" field 3228 representing VAP-4 1014. The "per-link information" field 3228 provides information about the represented VAP-4 1014, such as the link ID (indicated as "5") and the BSSID 3230 indicated as "0D-21". For example, the BSSID 3230 is used to Figure 33 The information in the RNR element 3300 is linked to the multilink element 3220. The RNR element 3300 includes information of the VAP-4 1014 in the "TBTT Information Set" field 3302, such as the BSSID (for link information to the multilink element 3220) and the short SSID of the SSID: Guest.

[0174] Note that in the multi-link element 3220 carried within the non-transmitted BSSID profile 1 of the multi-BSSID element 3218 in the beacon frame 3200 transmitted by VAP-1 1008, the "Host Link ID" field indicates that link ID "4" is assigned to the VAP (i.e., VAP-2 1010) corresponding to the non-transmitted BSSID profile 1. In this example, link ID "4" is different from link ID "1" assigned to VAP-1 1008 that transmitted the beacon frame 3200 because global link ID assignment is used rather than local link ID assignment.

[0175] Figure 34A diagram depicts a multilink element 3400 for unified signaling according to a fourth embodiment. Per-link information may be referred to as per-STA information (as shown in the "Per-STA Information" field 3402). Zero or more per-STA information fields may be present in the multilink element 3400, each field carrying information for one AP in an AP MLD or one STA in a non-AP MLD. The "Per-STA Information" field 3402 also includes information for the host AP transmitting the frame containing the multilink element, or for the host AP corresponding to a non-transmitted BSSID profile containing the multilink element. The "Transmitting STA" field 3404 (e.g., a bit set to 1) in the "Per-STA Information" field 3402 indicates that this "Per-STA Information" field 3402 carries information for the host AP, and the "Link ID" field 3406 indicates the link ID assigned to the link on which the host AP operates. For the host AP, the remaining fields of the "Per-STA Information" field may be omitted. At most, a host AP in a multilink element should have one "Per-STA Information" field. If some AP or VAP information is already carried in other elements, for example, if VAP-5 information is also carried in a Multi-BSSID element or an RNR element, only basic information about the link is provided, allowing the receiving non-AP STA to gather complete information by referencing other elements described in the previous embodiments. As a variation, instead of fields, each per-STA information 3402 can be a sub-element carrying its own element ID and length.

[0176] Figure 35 The fourth embodiment is described as follows Figure 10A and Figure 10B, which illustrates a beacon frame 3500 transmitted by VAP-1 1008 of network 1000. Also in this example, link ID assignment is global for co-located AP MLDs; that is, link IDs are unique to co-located MLDs. For example, AP MLD 1 has link IDs of 1 (VAP-1), 2 (VAP-3), and 3 (VAP-5), while AP MLD 2 has link IDs of 4 (VAP-2) and 5 (VAP-4). Within the multilink element 3502 of beacon frame 3500, there are three "Per-STA Information" fields 3508, 3510, and 3512, providing information for VAP-1 1008, VAP-3 1012, and VAP-5 1016, respectively. The "Per-STA Information" field 3508 indicates that the Transmitting STA field 3514 is "1," indicating that the VAP it represents (i.e., VAP-1 1008) is the transmitting STA for beacon frame 3500. Similarly, the "Transmitting STA" fields 3516 and 3518 are indicated as "0" as an indication that VAP-3 1012 and VAP-5 1016 are not transmitting STAs for beacon frame 3500. In the multilink element 3506 carried within the non-transmitting BSSID profile 1 of the multi-BSSID element 3504, the "Transmitting STA" field 3524 in the "Per STA Information" field 3520 is indicated as "1," indicating that the represented VAP-2 1010 is the VAP represented by the non-transmitting BSSID profile 1. The "Transmitting STA" field 3526 in the "Per STA Information" field 3522 is indicated as "0," indicating that the represented VAP-4 1014 is not the VAP represented by the non-transmitting BSSID profile 1. The Transmitting STA bit in the multilink element in the non-transmitting BSSID profile should not be confused as implying that the indicated VAP is a transmitting BSSID; it simply indicates that the VAP is represented by the non-transmitting BSSID profile. Note that in the multi-link element 3506 carried within the non-transmitting BSSID profile 1 of the multi-BSSID element 3504 in the beacon frame 3500 transmitted by VAP-1 1008, the "Transmitting STA" field 3524 is set to 1 in the first "Per-STA Information" field and indicates the link ID "4" assigned to the VAP corresponding to the non-transmitting BSSID profile 1 (i.e., VAP-2 1010). In this example, link ID "4" is different from link ID "1" assigned to VAP-1 1008 that transmitted the beacon frame 3500 because global link ID assignment is used instead of local link ID assignment.

[0177] In a deployment targeting only EHT devices, the neighbor MLD advertisement can be made more efficient by defining a new neighbor MLD report element 3600, such as Figure 36Each of the "Neighbor MLD Information" fields 3602 and 3604 carries a multilink element, i.e., multilink elements 3606 and 3608, respectively. Link information can be partial or complete. One bit in each "Neighbor Information" field is used to indicate a co-located MLD. For example, Figure 10A VAP-6 1018 in FIG. 1014 may advertise the co-located AP MLD 1 and AP MLD 2 by transmitting a neighbor MLD report element 3600 .

[0178] If some AP or VAP information is already carried in some other elements, for example, if VAP-5 information is also carried in the Multi-BSSID element or RNR element, then only basic information about the link is provided, which enables the receiving non-AP STA to gather complete information by referring to other elements described in the previous embodiments. Figure 10A 1000, and announces AP MLD1 1002 and APMLD2 1004. Since VAP-6 1018 is not included in any reported AP MLD, the "Transmitting STA" bit in all "Per-STA Information" fields is set to 0 in this case.

[0179] If the AP reported in the RNR element corresponds to a non-transmitted BSSID (indicated by the "BSS Parameters" field: Multiple BSSIDs = 1; Transmitted BSSID = 0), then the BSSID can be omitted from the RNR element, and instead the "Non-Transmitted BSSID Information" field is carried, which carries the information required to identify the transmitted BSSID corresponding to the AP, as well as other information required to calculate the BSSID of the AP. Figure 37 Example signaling is shown in RNR element 3700 of FIGURE 37, in which the "BSSID" field 3702 is omitted because the "BSS Parameters" field 3704 (Multiple BSSIDs = 1; Transmitted BSSID = 0) indicates that the RNR element corresponds to an untransmitted BSSID. Therefore, RNR element 3700 instead carries the "Untransmitted BSSID Information" field 3706 to identify the transmitted BSSID corresponding to the AP and other information required to calculate the AP's BSSID.

[0180] During a typical multi-link setup process, non-AP STAs will include their links' MAC addresses in the multi-link element, and if the multi-link setup is successful, then the AP MLD will update its record of the non-AP MLD with the MAC address. However, in some deployments, such as in enterprise networks, the non-AP MLD may be assigned its link's MAC address by the network. Initially, the non-AP MLD may contain only one global MAC address, which is used as both the MLD MAC address and the link MAC address for any one link at the time of discovery and multi-link setup. During multi-link setup (see Figure 38 In the Association Request frame 3800, a non-AP STA may request a MAC address for one or more of its links by including one or more FILS HLP container elements 3802 in the Multilink Setup frame (e.g., in the Association Request frame 3800, where the "Type" field 3808 of the Multilink element 3806 is indicated as "Multilink Setup"). The FILS HLP container 3802 may carry a DHCPv6 packet 3804 requesting one or more MAC addresses from the connected DHCP server. In such cases, the non-AP MLD may omit the "MAC Address" field in the Multilink element. For example, the MAC address of the non-AP STA corresponding to the link is not included in the "Per-Link Information" field of the Multilink element 3806. The absence of an L2 MAC address and the inclusion of a FILS HLP container 3802 in the Association Request frame 3800 alerts the AP MLD that the non-AP MLD is using a higher-layer protocol to request an L2 MAC address. The non-AP MLD's MLD MAC address is used as the TA / RA in the Association Request / Response frames and any other frames (as shown in the "TA" field 3810 of the Association Request frame 3800) until the non-AP MLD-AP MLD has obtained and updated its L2 MAC address. The AP MLD will then obtain the non-AP MLD's MAC address (e.g., from a DHCP server) and transmit it to the non-AP MLD following the higher layer protocol encapsulation process described in the 802.11 specification, either in the Association Response frame or in subsequent data frames. Once the MAC address has been installed in the non-AP MLD, it can notify the AP of its link MAC address by sending a dedicated frame carrying a multilink element (e.g., an Update MAC Address action frame) that carries the MAC address in its "Per-Link Information" field; or the non-AP MLD can use a multilink reset frame (such as an Update MAC Address action frame). Figure 39The AP MLD receives a multilink reset frame 3900 (e.g., multilink reset frame 3900) or any other suitable frame carrying a multilink element with the type field set to "Update MAC Address" (as shown in "Type" field 3904 of multilink element 3902), and the per-link information carries the MAC address of each link. Multilink reset frame 3900 may be a reassociation request frame. Upon receiving the MAC address, the AP MLD updates its record of the non-AP MLD and can continue to communicate with the non-AP MLD on all links using the L2 MAC address.

[0181] According to the fifth embodiment, beacon and probe response frames carry multilink elements, which carry only MLD common information (e.g., MLD MAC address, host link ID) but not information about other links of MLD. Host frames carry RNR elements or neighbor report elements, which carry information about all co-located APs (i.e., APs located in the same physical device). Example beacon and probe response frame 4000 is shown in FIG. Figure 40 As shown in FIG, information of all co-located APs is carried in the RNR or Neighbor Report element 4002, while the Multilink Element 4004 carries only the MLD MAC address and the Host Link ID. Of course, the MLD MAC address and the Host Link ID may not be included in the Multilink Element, but may be directly carried as fields in the Beacon / Probe Response frame.

[0182] The RNR element or neighbor report element according to the fifth embodiment indicates which of the reported APs are also attached to the MLD to which the AP transmitting the frame is attached. Figure 41In the RNR element 4100 shown in FIG4 , if the reported AP is part of a multi-BSSID set, such as VAP-2 shown in TBTT information set 4102, then BSSID index 4108, along with "BSSID" field 4104, indicates the corresponding transmitted BSSID (i.e., VAP-1). Additionally, a 1-bit in "BSS Parameters" field 4106 (or "TBTT Information Header" field 4110) indicates whether the AP reported in RNR element 4100 is affiliated with the same AP MLD whose MLD MAC address is carried in the frame carrying this RNR element. The RNR element may also include a change sequence number, which indicates a critical change in the BSS parameters of the AP reported by this TBTT information set. Upon receiving the RNR element, the non-AP MLD associated with the AP MLD to which the reporting AP is attached can compare the change sequence number with the locally stored change sequence number. If they differ, it is alerted to some critical changes to the BSS parameters of the reported AP and can continue to recover the relevant BSS parameters by listening to beacon / probe response frames transmitted by the reported AP. Alternatively, BSS Index 4108 may also refer to a unique index assigned to the reported AP among all co-located APs. By comparing the BSS index with the mapping of BSS indexes and co-located AP MLDs, the non-AP MLD receiving this RNR element can find out which reporting AP is attached to which AP MLD.

[0183] Figure 42 A diagram of a network 4200 according to a sixth embodiment is depicted. The network 4200 is similar to Figure 5A and Figure 5B This network 500 is similar to the one shown in Figure 5, but also supports additional SSIDs specifically catering to legacy non-AP STAs. In addition to advertising SSID: Multi-links, AP-1 4204 also advertises SSID: 5GHz_Link specifically for legacy non-AP STAs operating on the 5 GHz band, and AP-2 506 also advertises SSID: 2.4GHz_Link specifically for legacy non-AP STAs operating on the 2.4 GHz band (e.g., legacy STA 4220). In this deployment, the existing "SSID" field in beacon frames transmitted by the AP carries the SSID assigned to legacy non-AP STAs, while the SSID assigned to non-AP MLDs is advertised within the Multi-link element. In this way, it is possible to create separate network policies for MLDs and legacy STAs.

[0184] Figure 43A Depicted, for example, by Figure 42Figure 4300 shows a beacon frame transmitted by AP-1 4304 in the beacon frame. In the "SSID" field 4310 of the beacon frame, the SSID: 5GHz_link is advertised for legacy non-AP STAs. Information about AP MLD1 4202 is advertised in the Multilink Element 4312. Multilink Element 4312 carries basic information about all three APs of AP MLD1 4202. The first "Per-STA Information" field carries information about AP-1 4204, and therefore, the "Transmitting STA" bit 4320 is set to 1. It also carries the "SSID" field 4330 set to "Multi-links." Similarly, the second "Per-STA Information" field carries information about AP-2 4206, and therefore, the "Transmitting STA" bit is set to 0. It also carries the SSID field 4340, also set to "Multi-links." Similarly, the third "Per-STA Information" field carries information about AP-3 4208, and therefore, the "Transmitting STA" bit 5 is set to 0. It also carries the "SSID" field 4350 set to "Single-link" because AP-3 4208 caters to single-link non-MLD devices. Of course, if AP-3 4208 also caters to legacy non-AP STAs, it could advertise a different SSID for legacy non-AP STAs, or it could use the same "Single-link" SSID for legacy non-AP STAs. If all APs affiliated with an AP MLD advertise the same SSID for non-AP MLDs on all links, the non-AP MLD's SSID can be signaled in the "Common Information" field, and the "SSID" field can be omitted from the "Per-STA Information" field. Alternatively, if the SSID advertised by the AP MLD's AP is the same as the SSID for legacy STAs, the "SSID" field can be omitted entirely in the Multi-Link Element, and non-AP MLDs receiving this beacon (and the Multi-Link Element) will infer the SSID based on inheritance.

[0185] It is also possible that instead of (or in addition to) the Multi-link element 4312, one or more RNR elements may also be used to advertise SSIDs for non-APMLDs by including a list of short SSIDs corresponding to one or more covered SSIDs in the RNR element: Multi-links. Figure 43B This is illustrated in the figure, where RNR element 4360 announces Figure 42The RNR element contains information about AP-1 4204. The "Short SSID" field 4370 indicates the short SSID used for legacy and non-AP STAs, and a new field, Overlaid_SSID_List 4380, is added to the RNR element to advertise one or more short SSIDs corresponding to SSIDs overlaid on the legacy SSID, i.e., other SSIDs that AP-1 4204 also supports on the same link. In this example, Overload_SSID_List carries a single short SSID corresponding to SSID: Multi-links. Upon receiving the RNR element, the non-AP MLD can conclude that AP-1 4204 also provides access to the Multi-Links network.

[0186] In this deployment, it can be seen that the SSID used for non-AP MLD (i.e., SSID: Multi-links) is overlaid on link 1 (AP-1) and link 2 (AP-2). Therefore, the MLME-START.request primitive used when starting the BSS on AP-1 and AP-2 needs to be modified to also include a parameter Overlaid_SSID_List, which indicates a list of one or more SSIDs overlaid on the legacy network. For example, Overlaid_SSID_List includes SSID: Multi-links in the case of AP-1 4204 and AP-2 4206, and SSID: Single-link in the case of AP-3 4208. An example of such an MLME-START.request primitive is as follows:

[0187] MLME-START.request(

[0188] SSID,

[0189] BSSType,

[0190] …,

[0191] Overlaid_SSID_List )

[0193] When one or more SSIDs are overloaded on legacy SSIDs, a potential problem arises when a physical AP serves both legacy non-AP STAs and non-AP MLDs. The AP will transmit broadcast and group address data frames belonging to both SSIDs on the same link (channel). For example, AP-1 4204 will transmit a broadcast data frame (link 1) for SSID:Multi-links on the 5GHz link, intended for non-AP MLD-1 on the 5GHz link. However, legacy non-AP STA 4220 operating on the 5GHz link will also receive this broadcast data frame. Because the transmitter address (TA) is set to AP-1's MAC address and the receiver address (RA) is set to the broadcast MAC address, legacy non-AP STA 4220 will believe the frame is intended for it and will attempt to decode it. However, because the group security key (GTK) for SSID:Multi-links may differ from the GTK for SSID:5GHz_link, the non-AP STA will be unable to decode the data payload. This problem may also occur in other cases, ie, broadcast data frames for legacy STAs will also be decoded unnecessarily by non-AP MLDs.

[0194] One way to overcome this problem is to use the MLD MAC address as Figure 44A 4400). Here, the "TA" field 4410 is set to the MLD MAC address of AP MLD-1 4202. Since the TA is different from the MAC address of AP-1, legacy non-AP STAs will discard this frame, but since the non-AP MLDs know the MLD MAC address, they will correctly receive the broadcast data frame 4400. Similarly, the non-AP MLDs can be configured to ignore any broadcast data frames that contain the AP's L2 MAC address in the "TA" field. A similar approach can also be used for broadcast management frames that are intended only for non-AP STAs associated with a specific SSID. However, in the case of management frames, by setting Address 3 to the AP MLD's MAC address instead of the link's BSSID (i.e., the L2 MAC address of the affiliated AP operating on the link), the "Address 3" field can be used instead of the "Address 2" (TA) field to distinguish broadcast frames intended for non-AP MLDs. Reference is made to the FIGURE 4402 of FIGURE 4403. Figure 42 The AP-14204 transmission Figure 44BIn a broadcast management frame 4420, the "TA" field 4430 is set to the L2 MAC address of AP-1 4204 (0A-21), but the "BSSID" field 4432 is set to the MLD MAC address of AP MLD-1 4202 (0A-20). Because the BSSID differs from AP-1's MAC address, legacy non-AP STAs will discard this frame. However, since the non-AP MLD knows the MLD MAC address, they will correctly receive the broadcast management frame 4420. Similarly, with the exception of certain critical broadcast frames (such as beacon frames, probe response frames, FILS discovery frames, and channel switch announcement frames), non-AP MLDs can be configured to ignore other types of broadcast management frames that contain the AP's L2 MAC address in the "BSSID" field.

[0195] While the two approaches mentioned above can help avoid broadcast storms for specific types of frames, a more general approach applicable to all frame types can also be envisioned. Figure 44C A generic MAC frame 4440 is illustrated that is specifically designed for split network scenarios, such as when interconnecting with VLANs, or when two or more SSIDs are overlaid on the same wireless channel. The MAC frame 4440 differs from the legacy MAC frame, for example, by setting the "Protocol Version" field 4442 in the "Frame Control" field of the MAC header to a previously unused value (e.g., 2). When the "Protocol Version" field 4442 is set to this new value (e.g., 2) and higher, a new field "VLAN ID" 4446 is carried in the MAC frame, for example, just before the "Frame Body" field. When an AP interconnects a wireless network with a wired network that implements VLANs, the "VLAN ID" field 4446 is set to the corresponding VLAN ID used in the wired network (e.g., Figure 7 and Figure 12 ). If the AP does not interconnect with a wired VLAN, a unique VLAN ID is assigned to each SSID operating in the link and communicated with non-AP STAs operating in the link, such as during the association process.

[0196] For example, in Figure 42In network 4200, in addition to SSID: Multi-links, another SSID: Multi-links-guest can also be served by AP-1 4204 and AP-2 4206 on links 1 and 2, respectively. VLAN IDs 1 and 2 can be assigned to SSID: Multi-links and SSID: Multi-links-guest, respectively. In all MAC frames destined for non-AP MLDs or non-AP STAs that have joined SSID: Multi-linkss, the "VLAN ID" field 4446 is set to 1, while in all MAC frames destined for non-AP MLDs or non-AP STAs that have joined SSID: Multi-links-guest, the "VLAN ID" field 4446 is set to 2. Non-AP MLDs or non-AP STAs can further filter MAC frames based on the "VLAN ID" field 4446 (in addition to filtering based on the "RA / TA / BSSID" fields). As per conventional methods, the "TA" field 4444 is set to the L2 MAC address of the transmitting STA.

[0197] However, another approach to avoiding broadcast storms is to introduce a new frame type (e.g., a new data frame type) understood only by EHT devices. All data frames intended for EHT devices (MLD or non-MLD) would use the new data frame type. Alternatively, the 11be specification could mandate that data frames intended for EHT and future revision STAs always be carried in EHT PPDUs (rather than in legacy PPDUs: 11a, 11n, 11ac, or 11ax). Since legacy devices cannot decode EHT PPDUs, they will discard data frames intended only for EHT and future revision STAs. In these ways, the broadcast storms that initially create VLANs and VAPs can be avoided.

[0198] Figure 45 A flowchart 4500 illustrating a communication method according to various embodiments is shown. At step 4502, a frame is generated at an AP included in a plurality of APs affiliated with an AP MLD, wherein each of the plurality of APs advertises a BSSID and provides a link identified by a link ID, the frame carrying a multilink element containing information about the AP MLD and the plurality of APs. At step 4504, the frame is transmitted on the link, the multilink element indicating the link ID of the link on which the frame is transmitted.

[0199] Figure 46Schematic partial cross-sectional views of a communication device 4600 that can be implemented for EHT virtualization according to the first to sixth embodiments are shown. According to various embodiments, the communication device 4600 can be implemented as a STA or AP included in a plurality of STAs or APs attached to an AP MLD or a non-AP MLD.

[0200] The various functions and operations of the communication device 4600 are arranged into layers according to a hierarchical model. In this model, lower layers report to and receive instructions from higher layers according to IEEE specifications. For simplicity, the details of the hierarchical model are not discussed in this disclosure.

[0201] like Figure 46 As shown in FIG, a communication device 4600 may include circuitry 4614, at least one radio transmitter 4602, at least one radio receiver 4604, and multiple antennas 4612 (for simplicity, for illustration purposes, Figure 46 (Only one antenna is depicted in the figure). The circuitry may include at least one controller 4606 for software and hardware-assisted execution of the tasks it is designed to perform, including controlling communications with one or more other multi-link devices in a MIMO wireless network. The at least one controller 4606 may control at least one transmit signal generator 4608 to generate frames to be transmitted via at least one radio transmitter 4602 to one or more other STAs, APs, or MLDs, and at least one receive signal processor 4610 to process frames received via at least one radio receiver 4604 from one or more other STAs, APs, or MLDs. The at least one transmit signal generator 4608 and the at least one receive signal processor 4610 may be independent modules of the communication device 4600 that communicate with the at least one controller 4606 to implement the aforementioned functionality. Alternatively, the at least one transmit signal generator 4608 and the at least one receive signal processor 4610 may be included in the at least one controller 4606. Those skilled in the art will appreciate that the arrangement of these functional modules is flexible and may vary based on actual needs and / or requirements. Data processing, storage and other related control means may be provided on appropriate circuit boards and / or in chipsets.

[0202] In various embodiments, when in operation, at least one radio transmitter 4602, at least one radio receiver 4604, and at least one antenna 4612 may be controlled by at least one controller 4606. Furthermore, while only one radio transmitter 4602 is shown, it should be appreciated that more than one such transmitter may be present.

[0203] In various embodiments, when in operation, at least one radio receiver 4604 and at least one receive signal processor 4610 together form a receiver of the communication device 4600. The receiver of the communication device 4600, when in operation, provides the functionality required for multi-link communication. Although only one radio receiver 4604 is shown, it should be appreciated that more than one such receiver may be present.

[0204] When in operation, communication device 4600 provides the functionality required for EHT virtualization. For example, communication device 4600 may be an AP included in multiple APs affiliated with an AP Multi-Link Device (MLD), where each of the multiple APs advertises a BSSID and provides links identified by link identifiers (IDs). Circuitry 4614 may generate a frame carrying a multilink element, which contains information about the AP MLD and the multiple APs. Transmitter 4602 may transmit a frame on a link, where the multilink element indicates the link ID of the link on which the frame is transmitted.

[0205] The AP may be a member of a multiple BSSID set or a co-hosted BSSID set, or not a member of a multiple BSSID set or a co-hosted BSSID set, and wherein the frame may be a beacon frame, a probe response frame, a FILS discovery frame, or an association response frame.

[0206] An AP may be a member of a multi-BSSID set, and circuitry 4314 may be further configured to include a multi-BSSID element in the frame, the multi-BSSID element including an untransmitted BSSID profile carrying another multi-link element, the other multi-link element containing information about another AP MLD to which another AP corresponding to the untransmitted BSSID profile is attached and a plurality of links to which the other AP MLD is attached, the other multi-link element further indicating a link ID of a link on which the other AP operates. The other multi-link element may also include a "type" field, a "common information" field carrying the link ID of the link on which the other AP operates, and one or more "per-link information" fields, each "per-link information" field indicating a link of the plurality of links attached to the other AP MLD excluding the link on which the other AP operates, each "per-link information" field carrying the link ID of the indicated link and link-specific information indicating the BSSID and operating channel associated with the indicated link. If the SSID of the link is different from the SSID of the link carried in the "common information" field, the link-specific information may also indicate the SSID corresponding to the BSSID of the indicated link. If the represented link corresponds to a non-transmitted BSSID, the link-specific information may also indicate the transmitted BSSID, the maximum BSSID indicator, and the BSSID index corresponding to the non-transmitted BSSID.

[0207] Each BSSID may be included in a plurality of BSSIDs attached to the AP MLD, wherein the plurality of BSSIDs may be mapped to two or more SSIDs, and wherein the multilink element may further indicate the SSID corresponding to each link. The SSID or one or more BSSIDs mapped to the SSID may be indicated in the MAC data service primitive MA-UNITDATA.request, and wherein the transmitter 4602 may further be configured to transmit a data frame corresponding to the MAC data service primitive MA-UNITDATA.request if the AP corresponds to the one or more BSSIDs mapped to the SSID.

[0208] Each BSSID may be included in multiple BSSIDs attached to an AP MLD, where the multiple BSSIDs may be mapped to a single SSID, and where the multilink element may further indicate the SSID. The AP MLD may bridge wireless frames between multiple APs and a network implementing multiple VLANs, such that each SSID in the multiple SSIDs is mapped to a corresponding VLAN. The multilink element may further include a "type" field, a "common information" field carrying the link ID of the link on which the multilink element is transmitted, and one or more "per-link information" fields, each of which indicates a link in the multiple APs that is not included in the link on which the multilink element is transmitted. Each "per-link information" field carries the link ID of the represented link and link-specific information indicating the BSSID and operating channel associated with the represented link. If the SSID is different from the SSID of the link carried in the "common channel" field, the link-specific information may further indicate the SSID corresponding to the BSSID of the represented link. If the represented link corresponds to a non-transmitted BSSID, the link-specific information may also indicate the transmitted BSSID, the maximum BSSID indicator, and the BSSID index corresponding to the non-transmitted BSSID.

[0209] Circuitry 4614 may also be configured to provide information about one or more other APs by including one or more Neighbor Report elements or Reduced Neighbor Report (RNR) elements in the frame. The multi-link element may also indicate the BSSID and operating channel associated with each link of multiple APs that do not correspond to any AP included in the Neighbor Report element or RNR element. If the reporting AP is affiliated with an AP MLD, the Neighbor Report or RNR element may also indicate the MLD MAC address of the AP MLD. If the AP indicated in the RNR element corresponds to a non-transmitted BSSID, the RNR element may also indicate the transmitted BSSID, maximum BSSID indicator, and BSSID index corresponding to the non-transmitted BSSID.

[0210] The circuit 4614 may also be configured to provide information of one or more AP MLDs different from the AP MLD to which the AP is attached by including a neighbor MLD report element in the frame that carries information of the one or more AP MLDs. The multi-link element may also include a "type" field, a "common information" field, and one or more "per-STA information" fields, each of which represents an AP from the plurality of APs, each of which carries a link ID and link-specific information of the represented AP; each of the "per-STA information" fields also carries a "transmitting STA" field that indicates whether the represented AP associated with the "per-STA information" field is the AP that transmits the frame carrying the multi-link element.

[0211] For example, communication device 4600 may be a non-AP STA included in a plurality of non-AP STAs affiliated with a non-AP MLD. Circuitry 4614 generates a probe request frame carrying a multilink element, the multilink element including the AP MLD's MLD MAC address and one or more link IDs of links affiliated with the AP MLD. Transmitter 4602 transmits a probe request frame to request information about the AP MLD and one or more links of the AP MLD. Circuitry 4614 may also be configured to generate a frame carrying another multilink element, the "Type" field of which is set to a value indicating an update MAC address, the other multilink element carrying the non-AP MLD's MLD MAC address and the MAC addresses of one or more links of the non-AP MLD. Transmitter 4302 may also be configured to transmit a frame requesting the AP MLD to update its record of the non-AP MLD's MAC addresses for one or more links.

[0212] The present disclosure can be implemented through software, hardware, or a combination of software and hardware. Each functional block used in the description of each embodiment above can be partially or entirely implemented by an LSI, such as an integrated circuit, and each process described in each embodiment can be partially or entirely controlled by the same LSI or a combination of LSIs. The LSI can be formed as a single chip, or a single chip can be formed to include some or all of the functional blocks. The LSI may include data inputs and outputs coupled thereto. The LSI herein is sometimes referred to as an IC, system LSI, super LSI, or extreme LSI, depending on the level of integration. However, the technology for implementing an integrated circuit is not limited to LSIs and can be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, an FPGA (field programmable gate array) that can be programmed after LSI fabrication, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, can be used. The present disclosure can be implemented as either digital or analog processing. If future integrated circuit technology replaces LSI due to advances in semiconductor technology or other derivative technologies, the functional blocks can be integrated using future integrated circuit technology. Biotechnology can also be applied.

[0213] The present disclosure may be implemented by any type of apparatus, device, or system having a communication function, which is referred to as a communication device.

[0214] A communication device may include a transceiver and processing / control circuitry. The transceiver may include and / or function as both a receiver and a transmitter. A transceiver functioning as both a transmitter and a receiver may include an RF (radio frequency) module including an amplifier, an RF modulator / demodulator, and one or more antennas.

[0215] Some non-limiting examples of such communication devices include phones (e.g., cellular (mobile) phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still cameras / camcorders), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, e-book readers, telehealth / telemedicine (remote health and medical) devices, and vehicles that provide communication functionality (e.g., cars, airplanes, ships), and various combinations thereof.

[0216] Communication devices are not limited to being portable or movable, and may also include any kind of non-portable or fixed apparatus, device, or system, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines, and any other “things” in an “Internet of Things (IoT)” network.

[0217] Communications may include exchanging data via, for example, cellular systems, wireless LAN systems, satellite systems, etc., and various combinations thereof.

[0218] The communication device may include a device, such as a controller or sensor, coupled to the communication device that performs the communication functions described in the present disclosure. For example, the communication device may include a controller or sensor that generates control signals or data signals used by the communication device that performs the communication functions of the communication device.

[0219] Communications equipment may also include infrastructure such as base stations, access points, and any other apparatus, device, or system that communicates with or controls devices such as the above non-limiting examples.

[0220] A non-limiting example of a station may be a station included in a first plurality of stations attached to a multi-link station logical entity (i.e., such as an MLD), wherein as part of the first plurality of stations attached to the multi-link station logical entity, the stations in the first plurality of stations share a common medium access control (MAC) data service interface to an upper layer, wherein the common MAC data service interface is associated with a common MAC address or traffic identifier (TID).

[0221] Therefore, it can be seen that this embodiment provides a communication device and method for EHT virtualization, especially for MLD devices.

[0222] Although exemplary embodiments have been presented in the foregoing detailed description of the present embodiment, it should be recognized that there are a large number of variations. It should also be recognized that the exemplary embodiments are examples and are not intended to limit the scope, applicability, operation, or configuration of the present disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments, and it should be understood that various changes may be made to the function and arrangement of the steps of the operating methods described in the exemplary embodiments and the modules and structures of the devices described in the exemplary embodiments without departing from the scope of the subject matter set forth in the appended claims.

Claims

1. An access point multi-link device (AP MLD), which is an access point multi-link device attached to multiple access points (APs), having: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multi-BSSID set for a first channel; as well as a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multi-BSSID set for a second channel; The first virtual AP advertises a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel, The first virtual AP has: a circuit configured to generate a frame including an SSID field representing the first public SSID, a multilink element for the AP MLD, and a multi-BSSID element for other AP MLDs, the multilink element including a MAC address of the AP MLD, the multi-BSSID element including a non-transmitting BSSID profile of a first non-transmitting BSSID attached to the first multi-BSSID set; as well as A transmitting unit transmits the frame on the first channel.

2. The access point multi-link device according to claim 1, wherein: The frame is one of a beacon frame and a probe response frame.

3. The access point multi-link device according to claim 1, wherein: The other AP MLD has: a third virtual AP corresponding to the first non-transmission BSSID, the first non-transmission BSSID being attached to the first multiple BSSID set for the first channel; as well as a fourth virtual AP corresponding to another BSSID, the other BSSID being any one of the second transmission BSSID and the second non-transmission BSSID attached to the second multi-BSSID set for the second channel; In a case where the other BSSID is the second transmission BSSID, the fourth virtual AP advertises a second common SSID for the first non-transmission BSSID and the second transmission BSSID on the second channel.

4. The access point multi-link device according to claim 3, wherein: The non-transmitting BSSID profile includes other multi-BSSID elements for the other AP MLDs that are different from the multi-BSSID element for the AP MLD.

5. The access point multi-link device according to claim 4, wherein: The other multi-BSSID element included in the non-transmission BSSID profile includes information related to the third virtual AP and the fourth virtual AP.

6. The access point multi-link device according to claim 1, wherein: Multiple virtual APs corresponding to the first multi-BSSID set operate on the first channel to form a first virtual AP set, and multiple virtual APs corresponding to the second multi-BSSID set operate on the second channel to form a second virtual AP set.

7. The access point multi-link device according to claim 1, wherein: The multi-link element includes: a common information field including the MAC address of the AP MLD; and a per-link information field including link information of the second virtual AP.

8. The access point multi-link device according to claim 7, wherein: The per-link information field includes a link ID subfield and a non-transmission BSSID information field.

9. The access point multi-link device according to claim 3, comprising: a fifth virtual AP corresponding to a third BSSID, the third BSSID being any one of a third transmission BSSID and a third non-transmission BSSID attached to a third multi-BSSID set for a third channel, The first virtual AP advertises the first public SSID that is also shared by the third BSSID. When the third BSSID is the third transmission BSSID, the third virtual AP advertises the first public SSID on the third channel.

10. The access point multi-link device according to claim 9, wherein: The multi-link element includes a per-link information field, where the per-link information field includes link information of the second virtual AP and the third virtual AP.

11. A communication method in an access point multi-link device (AP MLD) to which multiple access points (APs) are attached, wherein: The AP MLD comprises: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multiple BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multi-BSSID set for a second channel, The first virtual AP advertises a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel, The communication method comprises: a frame generating step of generating, by the first virtual AP, a frame including an SSID field indicating the first public SSID, a multilink element for the AP MLD, and a multi-BSSID element for other AP MLDs, wherein the multilink element includes a MAC address of the AP MLD, and the multi-BSSID element includes a non-transmission BSSID profile of a first non-transmission BSSID attached to the first multi-BSSID set; as well as A frame transmission step is performed, wherein the frame is transmitted on the first channel through the first virtual AP.

12. The communication method according to claim 11, wherein: The frame is one of a beacon frame and a probe response frame.

13. The communication method according to claim 11, wherein: The other AP MLD has: a third virtual AP corresponding to the first non-transmission BSSID, the first non-transmission BSSID being attached to the first multiple BSSID set for the first channel; as well as a fourth virtual AP corresponding to another BSSID, the other BSSID being any one of the second transmission BSSID and the second non-transmission BSSID attached to the second multi-BSSID set for the second channel; In a case where the other BSSID is the second transmission BSSID, the fourth virtual AP advertises a second common SSID for the first non-transmission BSSID and the second transmission BSSID on the second channel.

14. The communication method according to claim 13, wherein: The non-transmitting BSSID profile includes other multi-BSSID elements for the other AP MLDs that are different from the multi-BSSID element for the AP MLD.

15. The communication method according to claim 14, wherein: The other multi-BSSID element included in the non-transmission BSSID profile includes information related to the third virtual AP and the fourth virtual AP.

16. The communication method according to claim 11, wherein: Multiple virtual APs corresponding to the first multi-BSSID set operate on the first channel to form a first virtual AP set, and multiple virtual APs corresponding to the second multi-BSSID set operate on the second channel to form a second virtual AP set.

17. The communication method according to claim 11, wherein: The multi-link element includes: a common information field including the MAC address of the AP MLD; and a per-link information field including link information of the second virtual AP.

18. The communication method according to claim 17, wherein: The per-link information field includes a link ID subfield and a non-transmission BSSID information field.

19. The communication method according to claim 13, comprising: a fifth virtual AP corresponding to a third BSSID, the third BSSID being any one of a third transmission BSSID and a third non-transmission BSSID attached to a third multi-BSSID set for a third channel, The first virtual AP advertises the first public SSID that is also shared by the third BSSID. When the third BSSID is the third transmission BSSID, the third virtual AP advertises the first public SSID on the third channel.

20. The communication method according to claim 19, wherein: The multi-link element includes a per-link information field, where the per-link information field includes link information of the second virtual AP and the third virtual AP.

21. An integrated circuit, which is an integrated circuit for an access point multi-link device (AP MLD) to which a plurality of access points (APs) are attached, wherein: The AP MLD comprises: a first virtual AP corresponding to a first basic service set identifier (BSSID), the first BSSID being a first transmission BSSID attached to a first multiple BSSID set for a first channel; and a second virtual AP corresponding to a second BSSID, the second BSSID being any one of a second transmission BSSID and a second non-transmission BSSID attached to a second multi-BSSID set for a second channel, The first virtual AP advertises a first public service set identifier (SSID) for the first BSSID and the second BSSID on the first channel, The integrated circuit controls: a frame generating step of generating, by the first virtual AP, a frame including an SSID field indicating the first public SSID, a multilink element for the AP MLD, and a multi-BSSID element for other AP MLDs, wherein the multilink element includes a MAC address of the AP MLD, and the multi-BSSID element includes a non-transmission BSSID profile of a first non-transmission BSSID attached to the first multi-BSSID set; as well as A frame transmission step is performed, wherein the frame is transmitted on the first channel through the first virtual AP.

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