Distributed access point multilink device

Abstract

Embodiments of the present disclosure relate to an architecture of a distributed AP MLD. An apparatus includes at least two upper MAC sublayer functional entities, and at least one intermediate MAC sublayer functional entity configured to be affiliated to at least one AP having a lower MAC sublayer functional entity. The at least one intermediate MAC sublayer functional entity is configured to communicate with the at least two upper MAC sublayer functional entities over the logical ports.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of communications, and in particular to distributed access point multi-link devices (AP MLDs). Background Art

[0002] Multi-link operation (MLO) has been identified as an important feature of Institute of Electrical and Electronics Engineers (IEEE) 802.11be. The goal of MLO is to operate efficiently within all available frequency bands (such as 2.4 GHz, 5 GHz, and 6 GHz) to achieve load balancing, multi-band aggregation, and simultaneous downlink and uplink transmissions. For MLO, an MLD manages communications on multiple links. Whether communications across different frequency bands or channels can occur simultaneously can depend on the capabilities of both AP MLDs and non-AP MLDs. Summary of the Invention

[0003] Example embodiments of the present disclosure provide an improved solution for the architecture of distributed AP MLDs.

[0004] In a first aspect, a device is provided. The device includes: at least two upper MAC sublayer functional entities, and at least one intermediate MAC sublayer functional entity configured to: be attached to at least one AP having a lower MAC sublayer functional entity. The at least one intermediate MAC sublayer functional entity is configured to communicate with the at least two upper MAC sublayer functional entities through logical ports.

[0005] In a second aspect, a device is provided. The device includes: components for implementing at least two upper MAC sublayer functional entities, and components for implementing at least one intermediate MAC sublayer functional entity configured to: be attached to at least one AP having a lower MAC sublayer functional entity. The at least one intermediate MAC sublayer functional entity is configured to communicate with the at least two upper MAC sublayer functional entities through logical ports.

[0006] In a third aspect, a method is provided. The method includes: implementing at least two upper media access control (MAC) sublayer functional entities; and attaching at least one intermediate MAC sublayer functional entity to at least one access point (AP) having a lower MAC sublayer functional entity, wherein the at least one intermediate MAC sublayer functional entity communicates with the at least two upper MAC sublayer functional entities through logical ports.

[0007] In a fourth aspect, an apparatus is provided. The apparatus includes at least one processor and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the apparatus to at least: implement at least two upper Medium Access Control (MAC) sublayer functional entities; and attach at least one intermediate MAC sublayer functional entity to at least one Access Point (AP) having a lower MAC sublayer functional entity, wherein at least one intermediate MAC sublayer functional entity communicates with at least two upper MAC sublayer functional entities via a logical port.

[0008] In a fifth aspect, a computer-readable medium is provided. The non-transitory computer-readable medium includes program instructions for causing an apparatus to execute the method according to the third aspect.

[0009] It should be understood that the Summary of the Invention section is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Some example implementations will now be described with reference to the accompanying drawings, in which:

[0011] Figure 1 An example of Multi-Link Operation (MLO) between an AP MLD and a non-AP MLD is illustrated;

[0012] Figure 2 The data plane architecture of the Medium Access Control (MAC) layer of a traditional AP MLD is illustrated;

[0013] Figure 3 An example apparatus according to some example implementations of the present disclosure is illustrated;

[0014] Figure 4 An example of the data plane architecture of the MAC layer of a distributed AP MLD according to some example implementations of the present disclosure is illustrated;

[0015] Figure 5 An example of MLO between a distributed AP MLD and a non-AP MLD according to some example implementations of the present disclosure is illustrated;

[0016] Figure 6 A simplified block diagram of an apparatus suitable for implementing the example implementations of the present disclosure is illustrated; and

[0017] Figure 7 A block diagram of an example computer-readable medium according to an example implementation of the present disclosure is illustrated.

[0018] Unless otherwise specified, throughout the drawings, the same or similar reference numerals denote the same or similar elements. DETAILED DESCRIPTION

[0019] The principles of the present disclosure will now be described with reference to some example implementations. It should be understood that these implementations are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing the present disclosure, and do not represent any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in a variety of other ways than those described below.

[0020] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0021] In the present disclosure, references to "one embodiment", "an embodiment", "example embodiment", etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, those skilled in the art will recognize that, whether or not explicitly described, the ability to combine such feature, structure, or characteristic with other implementations is within the knowledge of those skilled in the art.

[0022] It should be understood that although terms such as "first" and "second" may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the example implementation, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0023] The terms used herein are for the purpose of describing particular implementations only and are not intended to limit the example implementations. The singular forms "a", "an", and "the" used herein also include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "has", "having", "contains", and / or "including", when used herein, specify the presence of the stated features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0024] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0025] (a) A pure hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and

[0026] (b) A combination of hardware circuitry and software, such as (if applicable):

[0027] (i) A combination of (one or more) analog and / or digital hardware circuits and software / firmware, and

[0028] (ii) Any part of (one or more) hardware processors (including (one or more) digital signal processors), software, and (one or more) memories with software that work together to cause a device, such as a mobile phone or a server, to perform various functions), and

[0029] (c) (One or more) hardware circuits and / or (one or more) processors, such as (one or more) microprocessors or parts of (one or more) microprocessors, which require software (e.g., firmware)

[0030] to operate, but the software may be absent when not needed.

[0031] This definition of circuitry is suitable for all uses of the term in this application, including in any claim. As another example, as used in this application, the term circuitry also encompasses implementations of only hardware circuits or processors (or multiple processors) or parts of hardware circuits or processors along with their accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also encompasses a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or networking devices.

[0032] As used herein, the term "communication network" refers to a network that follows any suitable communication standard, such as but not limited to fifth-generation (5G) systems, Long-Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), Wi-Fi, etc. In addition, the communication between a terminal device and a network device in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G) New Radio (NR) communication protocols, and / or any other protocol known currently or to be developed in the future. Embodiments of the present disclosure can be applied to various communication systems. Considering the rapid development of communication, of course, there will also be future types of communication technologies and systems that can be used to embody the present disclosure. It should not be regarded as limiting the scope of the present disclosure to the above systems.

[0033] As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services from the network. The network device may refer to a base station (BS) or an access point (AP), such as Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NR NB (also referred to as gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, low-power node (such as femto, pico), etc., depending on the terminology and technology applied. The RAN split architecture includes a gNB-CU (centralized unit that hosts RRC, SDAP, and PDCP), which controls multiple gNB-DUs (distributed units that host RLC, MAC, and PHY). The relay node may correspond to the DU part of the IAB node.

[0034] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, the terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). The terminal device may include, but is not limited to, mobile phones, cellular phones, smart phones, IP voice (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), game terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, smart devices, wireless customer premise equipment (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMD), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automation processing chain environment), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. The terminal device may also correspond to the mobile terminal (MT) part of an integrated access and backhaul (IAB) node (also referred to as a relay node). In the following description, the terms "terminal device", "communication device", "terminal", "user equipment", and "UE" may be used interchangeably.

[0035] Figure 1 An example 100 of MLO between an AP MLD 120 and a non-AP MLD 110 is illustrated. As Figure 1As shown, the non-AP MLD 110 has attached non-AP stations (STAs) 111, 112, and 113. Hereinafter, for simplicity, the non-AP STAs are also referred to as STAs. The AP MLD 120 has attached APs 121, AP 122, and AP 123.

[0036] AP 121 operates on the 2.4 GHz band, AP 122 operates on the 5 GHz band, and AP 123 operates on the 6 GHz band. After MLD establishment or MLD re-establishment, three links on the 2.4 GHz, 5 GHz, and 6 GHz bands can be established for simultaneous communication between the AP MLD 120 and the non-AP MLD 110.

[0037] Figure 2 The figure illustrates the data plane architecture of the media access control (MAC) layer of a conventional AP MLD 120 with n links for unicast data frames. N is an integer equal to or greater than 2.

[0038] As Figure 2 shown, the AP MLD 120 includes IEEE 802.1X controlled and uncontrolled port filtering ports 230 and the MAC layer. For MLO, the MAC layer of the AP MLD 120 can be divided into an MLD upper MAC sublayer 210 and two MLD lower MAC sublayers 220.

[0039] The IEEE 802.1X controlled and uncontrolled ports 230 include an IEEE 802.1X controlled port (C) 231 and an IEEE 802.1X uncontrolled port (U) 232. The IEEE 802.1X controlled port 231 is blocked from passing general data traffic between two STAs or between two MLDs until the IEEE 802.1X authentication process is successfully completed on the IEEE 802.1X uncontrolled port 232. If the IEEE 802.1X controlled port 231 is not enabled and if the received MAC service data unit (MSDU) does not represent an IEEE 802.1X frame, the IEEE 802.1X controlled port 231 discards the received MSDU.

[0040] The IEEE 802.1X controlled and uncontrolled ports 230 communicate with the MLD upper MAC sublayer 210 through a single MAC service access point (MAC-SAP) 233.

[0041] The MLD upper MAC sublayer 210 performs functions that are common across all links. The MLD lower MAC sublayers 220 perform functions that are local to each link. Some of these functions require joint processing by both the MLD upper MAC sublayer 210 and the MLD lower MAC sublayers 220.

[0042] Specifically, the upper MAC sublayer 210 of the MLD includes: an RX / TX MSDU rate limiting block 2111, an A-MSDU aggregation or disaggregation block 2112, a PS deferral queuing block 2113, a sequence number (SN) assignment block 2114, a packet number (PN) assignment block 2115, a MAC protocol data unit (MPDU) encryption block 2116, a replay detection block 2117, a block acknowledgment (Ack) cache and reordering block 2118, an MPDU decryption block 2119, a duplicate detection block 2120, a block Ack scoring block 2121, and a traffic identifier (TID) to link mapping or merging block 2122.

[0043] The RX / TX MSDU rate limiting block 2111 is configured to perform resource utilization limiting at a specific rate.

[0044] The A-MSDU aggregation or disaggregation block 2112 is configured to allow several MAC-level service data units (MSDUs) to be aggregated into a single MPDU, or allow a single MPDU to be disaggregated into several MSDUs.

[0045] The PS deferral queuing block 2113 is configured to defer and cache MPDU transmissions for energy saving reasons, which means that the MPDU is assigned to a link in the upper MAC 210 and then cached until the energy saving state of the link is suitable for transmitting the MPDU.

[0046] The SN assignment block 2114 is configured to perform SN assignment on unicast frames to be encrypted by a pairwise transient key (PTK).

[0047] The PN assignment block 2115 is configured to perform PN assignment on unicast frames to be encrypted by a PTK.

[0048] The MPDU encryption block 2116 is configured to encrypt unicast frames with a PTK.

[0049] The replay detection block 2117 is configured to detect replay transmissions from an attacker who monitors the transmissions (passive attack) and retransmits messages posing as a legitimate user.

[0050] The block acknowledgment cache and reordering block 2118 is configured to perform reordering of packets to ensure in-sequence delivery for each block Ack session.

[0051] The MPDU decryption block 2119 is configured to decrypt unicast frames with a PTK.

[0052] If MAC-level acknowledgments and retransmissions are incorporated into the protocol, frames may be received more than once. The duplicate detection block 2120 is configured to attempt to filter out duplicate frame receptions.

[0053] The Block Ack scoring block 2121 is configured to perform Block Ack scoring on individually addressed frames in cooperation with the MLD lower MAC sublayer 220. Optionally, the MLD upper MAC sublayer 210 delivers the Block Ack record on one link to the MLD lower MAC sublayer of another link.

[0054] In the IEEE 802.11be specification, the TID-to-link mapping mechanism allows the AP MLD 120 and the non-AP MLD 110 that perform multi-link establishment to determine how the TIDs are mapped to the established links in the DL and UL. If a link is defined as a disabled link, no TIDs will be mapped to that link in the DL and UL, and thus the AP MLD 120 can dynamically manage the traffic delivery links of special non-AP MLDs according to the traffic scheduling policy.

[0055] The TID-to-link mapping or aggregation block 2122 is configured to: perform the selection of one of the MLD lower MAC sublayers 220 for transmission, or perform the aggregation of MPDUs from the selected MLD lower MAC sublayer.

[0056] Specifically, the MLD lower MAC sublayer 220 includes the following blocks associated with Link 1: the Block Ack scoring block 2210, the address filing block 2211, the MPDU header and CRC creation or verification block 2212, and the A-MSDU aggregation or de-aggregation block 2213.

[0057] The Block Ack scoring block 2210 is configured to perform Block Ack scoring on individually addressed frames in cooperation with the Block Ack scoring block 2121 in the MLD upper MAC sublayer 210. Optionally, the Block Ack scoring block 2210 is configured to receive the Block Ack record from the MLD upper MAC sublayer 210 on other links.

[0058] The address filing block 2211 is configured to perform MAC address filtering for frame reception.

[0059] The MPDU header and CRC creation or verification block 2212 is configured to create or verify the MPDU header and CRC.

[0060] The A-MSDU aggregation or de-aggregation block 2213 is configured to: allow several MSDUs to be aggregated into a single MPDU to be transmitted, or allow a single MPDU to be de-aggregated into several MSDUs.

[0061] The control plane functions of the MLD lower MAC sublayer may include at least one of the following:

[0062] · Maintain link-specific GTK / IGTK / BIGTK between the AP attached to the AP MLD 120 and the STA attached to the non-AP MLD 110;

[0063] · Use GTK / IGTK / BIGTK for link-specific encryption / decryption / integrity protection and PN assignment between the AP attached to the AP MLD 120 and the STA attached to the non-AP MLD 110;

[0064] · Link-specific management information (such as beacons) exchange / indication;

[0065] · Link-specific control information (such as RTS / CTS, acknowledgments, NDP) exchange / indication; or

[0066] · Control power-saving states and modes.

[0067] Similarly, the lower MLD MAC sublayer 220 includes the following blocks associated with link n: Block Ack Score Block 2220, Address Archive Block 2221, MPDU Header and CRC Creation or Verification Block 2222, and A-MSDU Aggregation or De-aggregation Block 2223. The functions of blocks 2220 to 2223 are the same as the functions of blocks 2210 to 2213.

[0068] During transmission, the MSDU from the MAC-SAP 233 goes through the process shown on the left side of

[0069] , and then goes through the TID-to-link mapping process in the TID-to-link mapping or merging block 2122. The TID-to-link mapping or merging block 2122 forwards the MPDU downward to one of the lower MLD MAC sublayers, and then forwards it to the corresponding PHY SAP ( Figure 2 not shown in Figure 2 ).

[0070] During reception, the MPDUs originating from different PHY SAPs first go through the lower MLD MAC sublayer, and then the merging process in the TID-to-link mapping or merging block 2122. Then, the MPDUs go through the process on the right side of Figure 2 . Then, one or more MSDUs are delivered to the MAC-SAP 233, or delivered to the distributed system (DS) via the distributed system access function (DSAF).

[0071] When using MLO, before transmission on the link, unicast MPDUs and MAC management protocol data units (MMPDUs) are encrypted using the same pairwise transient key security association (PTKSA). The same PTKSA is used to decrypt unicast MPDUs and MMPDUs received on the link. The group temporal key (GTK) of the link is used to encrypt group-addressed frame MPDUs and MMPDUs before transmission on the link. The GTK of the link is used to decrypt group-addressed frame MPDUs and MMPDUs received on the link.

[0072] When using MLO, the block Ack scoreboard 2121 in the MLD upper MAC sublayer 210 manages the block Ack status of MPDUs (of the block Ack session) received on any established link. Each of the block Ack scoreboards 2210 and 2220 in the MLD lower MAC sublayer 220 manages the block Ack status of MPDUs of the block Ack session received on that link. If each of the blocks in the block Ack scoreboards 2210 and 2220 obtains the block Ack status of MPDUs received on another link from the MLD upper MAC sublayer 210, then such a block can convey such information.

[0073] For MLO, the following outstanding issues still need to be resolved.

[0074] First, there will be a service interruption problem during the fast basic service set (BSS) transition between AP MLDs because, according to the latest IEEE 802.11be specification, it is not allowed for a non-AP MLD to be associated with two AP MLDs simultaneously. For example, when a non-AP MLD (such as a Wi-Fi 7 phone) moves away from its associated AP MLD and closer to an adjacent AP MLD, according to the rules defined by the latest draft of IEEE 802.11be, the non-AP MLD can disconnect from the current AP MLD and re-associate with the adjacent AP MLD. In this case, a service interruption problem may occur and lead to an interruption problem for low-latency services (such as AR, VR, XR, etc.), which is not a friendly design for terminal devices.

[0075] Second, generally, a co-located AP MLD can have only three links operating on three unlicensed frequency bands. For example, APs 121, 122, and 123 attached to AP MLD 120 operate on the 2.4 GHz band, 5 GHz band, and 6 GHz band, respectively. Due to in-band interference issues, it is difficult to have more links. If the frequency separation in the physical device is too short, this may cause the co-located APs 121, 122, and 123 attached to AP MLD 120 to interfere with each other. For example, assume that AP 121 and AP 122 attached to AP MLD 120 operate on channel 120 of 5 GHz and channel 149 of 5 GHz, respectively. AP 121 is sending a PPDU to the associated STA 111, while AP 122 remains in a listen mode of the clear channel assessment (CCA) state. Due to the short frequency separation, the transmission power of AP 121 operating on CH120 of 5 GHz may cause leakage into channel 149 of 5 GHz (and vice versa). This makes AP 122 always think the channel is busy, and AP 122 cannot send any frames to the corresponding STA 112.

[0076] Third, due to the co-located deployment of RF components, the coverage area and supported links of AP MLD 120 are limited. To support flexible coverage and range, the scalability of AP MLD 120 is an issue that will need to be addressed in next-generation Wi-Fi technologies.

[0077] Implementations of the present disclosure provide a solution for an architecture of a distributed AP MLD to address the above problems and one or more other potential problems. According to the solution, a device includes at least two upper MAC sublayer functional entities and at least one intermediate MAC sublayer functional entity, where the at least one intermediate MAC sublayer functional entity is configured to: be attached to at least one AP having a lower MAC sublayer functional entity. The at least one intermediate MAC sublayer functional entity is configured to: communicate with the at least two upper MAC sublayer functional entities via logical ports.

[0078] In the following, reference will be made to Figures 3 to 7 describe the principles of the present disclosure.

[0079] Figure 3FIG. illustrates an example apparatus 300 in accordance with some example implementations of the present disclosure. In some embodiments, the apparatus 300 may be implemented as a distributed AP MLD. The distributed AP MLD may increase the throughput of non-AP MLDs communicating with the distributed AP MLD through the aggregation of multiple links associated with multiple physical devices. In other embodiments, the apparatus 300 may be implemented as any other suitable device. The scope of the present disclosure is not limited in this regard. Hereinafter, some embodiments of the present disclosure will be described by taking the distributed AP MLD as an example.

[0080] In embodiments where the apparatus 300 is implemented as a distributed AP MLD, the intermediate MAC sublayer functional entity is also referred to as the MLD intermediate MAC sublayer functional entity, and the lower MAC sublayer functional entity is also referred to as the MLD lower MAC sublayer functional entity.

[0081] As Figure 3 shown, the apparatus 300 includes: an MLD upper MAC sublayer functional entity 310, a first MLD intermediate MAC sublayer functional entity 321, and a second MLD intermediate MAC sublayer functional entity 331.

[0082] The first MLD intermediate MAC sublayer functional entity 321 is configured to be attached to AP 3221 and AP 3222. Each of AP 3221 and AP 3222 has an MLD lower MAC sublayer functional entity. The second MLD intermediate MAC sublayer functional entity 331 is configured to be attached to AP 3321 and AP 3322. Each of AP 3321 and AP 3322 has an MLD lower MAC sublayer functional entity.

[0083] The first MLD intermediate MAC sublayer functional entity 321 is configured to communicate with the MLD upper MAC sublayer functional entity 310 through a logical port 323 to implement the functions of the MAC layer. The second MLD intermediate MAC sublayer functional entity 331 is configured to communicate with the MLD upper MAC sublayer functional entity 310 through a logical port 333 to implement the functions of the MAC layer.

[0084] In some embodiments, the apparatus 300 may include a single MAC SAP 340 for logical link control (LLC). The MAC-SAP 340 may include one MAC data service.

[0085] In some embodiments, the first MLD intermediate MAC sublayer functional entity 321, and AP 3221 and AP 3222 may be deployed in a first physical device 320, as Figure 3As shown. Each of the APs in AP 3221 and AP 3222 can operate on a link. Similarly, the second MLD intermediate MAC sublayer functional entity 331 and APs 3321 and 3322 can be deployed in a second physical device 330 different from the first physical device 320, as Figure 3 shown. Each of the APs in AP 3321 and AP 3322 can operate on a link. The apparatus 300 can enable MLO through physical devices 320 and 330.

[0086] In some embodiments, when transmitting the MLD data frame 311 with a non-AP MLD, the first physical device 320 and the second physical device 330 can share a single MLD upper MAC sublayer functional entity 310. The APs 3221 and 3222 can share the first MLD intermediate MAC sublayer functional entity 321. The APs 3321 and 3322 can share the second MLD intermediate MAC sublayer functional entity 331.

[0087] In addition, the apparatus 300 further includes a first non-MLD upper MAC sublayer functional entity 350 and a second non-MLD upper MAC sublayer functional entity 360.

[0088] In some embodiments, the first non-MLD upper MAC sublayer functional entity 350 can be associated with the AP 3221 for the transmission of the non-MLD data frame 351. The second non-MLD upper MAC sublayer functional entity 360 can be associated with the AP 3322 for the transmission of the non-MLD data frame 361. In some embodiments, the non-MLD data frames 351 and 361 can be data frames going to or from a legacy (non-MLD) STA, or group addressed MLD data frames.

[0089] In this way, even if the non-AP MLD moves from one physical device to another physical device, the distributed AP MLD 300 can connect to the non-AP MLD with the best link, which will not result in a throughput reduction. In addition, due to the extended coverage, the non-AP MLD can always connect to a large area of the distributed AP MLD without consuming a large amount of power on the non-AP MLD, nor incurring the handover cost of re-association or re-negotiating security.

[0090] In some embodiments, the first non-MLD upper MAC sublayer functional entity 350 can be configured to communicate with the lower MAC sublayer functional entity of the AP 3221 through the logical port 323 using a tunnel transparent to the first intermediate MAC sublayer functional entity 321.

[0091] In some embodiments, the apparatus 300 can be implemented as a logical entity.

[0092] In some embodiments, the MLD upper MAC sublayer functional entity 310 and the non-MLD upper MAC sublayer functional entities 350 and 360 may be implemented in one of the physical devices 320 and 330.

[0093] In some embodiments, the MLD upper MAC sublayer functional entity 310 and the non-MLD upper MAC sublayer functional entities 350 and 360 may be implemented in a third device different from the physical devices 320 and 330. For example, the third device may include a network device.

[0094] In some embodiments, each of the physical devices 320 and 330 may be implemented as a pluggable physical device. In this way, the distributed AP MLD can provide good scalability to change the number of physical devices so as to meet the coverage and / or cost requirements. Generally, the cost of the physical device will be lower than that of a traditional AP MLD with the same attached APs.

[0095] In some embodiments, the physical devices 320 and 330 may be transparent to non-AP MLDs communicating with the device 300. After the MLD is established or re-established, one or more APs attached to one or more MLD intermediate MAC sublayer functional entities among the MLD intermediate MAC sublayer functional entities 321 and 331 may be used for communication between the distributed AP MLD 300 and non-AP MLDs. Therefore, the distributed AP MLD can be well compatible with traditional non-AP MLDs because the physical devices 320 and 330 are transparent to non-AP MLDs.

[0096] It should be understood that Figure 3 the number of MLD intermediate MAC sublayer functional entities in the device 300 as shown, the number of APs attached to the MLD intermediate MAC sublayer functional entities 321 and 331, and the number of non-MLD upper MAC sublayer functional entities are for illustrative purposes only and do not represent any limitation. The device 300 may include any suitable number of MLD intermediate MAC sublayer functional entities, any suitable number of APs, and any suitable number of non-MLD upper MAC sublayer functional entities adapted to implement the embodiments of the present disclosure.

[0097] In some embodiments, the MLD upper MAC sublayer functional entity 310 may include: common functions across all the MLD intermediate MAC sublayer functional entities 321 and 331.

[0098] In some embodiments, a TID may be mapped to a set of multiple links to allow any link in the set to be used to transmit traffic having that TID. In this way, higher-rate traffic having that TID can be processed, and the congested queue for that TID will be emptied faster. The MLD upper MAC sublayer function entity 310 on the transmitter side may be configured to collect at least one of the following: the TID-to-link mapping or the queue status of the TID. For example, the MLD upper MAC sublayer function entity 310 on the transmitter side may be configured to collect the queue status of the locally stored TID. Additionally or alternatively, the MLD upper MAC sublayer function entity 310 on the transmitter side may be configured to collect the queue status of the TID from the MLD middle MAC sublayer function entities 321 and 331. Further, the MLD upper MAC sublayer function entity 310 may be configured to select one of the MLD middle MAC sublayer function entities 321 and 331 for transmitting or retransmitting traffic having the TID based on at least one of the following: the TID-to-link mapping, or the queue status of the TID.

[0099] In some embodiments, different from traditional AP MLDs, the block Ack scorekeeping at the MLD upper MAC sublayer function entity 310 may be based on cooperation with at least one of the MLD middle MAC sublayer function entities 321 and 331. In such an embodiment, the MLD upper MAC sublayer function entity 310 may be configured to: obtain the block Ack status of the MPDU from the first MLD middle MAC sublayer function entity 321, and schedule the retransmission of the MPDU across the MLD middle MAC sublayer function entities 321 and 331 based on the block Ack status.

[0100] In some embodiments, the MLD upper MAC sublayer function entity 310 may be configured to: provide the block Ack status to the second MLD middle MAC sublayer function entity 331.

[0101] In some embodiments, the first MLD middle MAC sublayer function entity 321 may include: common functions across all subordinate links.

[0102] In some embodiments, the first MLD middle MAC sublayer function entity 321 may be configured to: provide the MLD upper MAC sublayer function entity 310 with the capability information and operation parameters of each link associated with the APs 3221 and 3222.

[0103] Alternatively, in some embodiments, the apparatus 300 may further include Figure 3A station management entity (SME) not shown in the figure. The SME, the MLD upper MAC sublayer functional entity 310, the non-MLD upper MAC sublayer functional entities 350 and 360 can be implemented in a single physical device within the apparatus 300.

[0104] In some embodiments, the first MLD middle MAC sublayer functional entity 321 can be configured to: provide the SME with the capability information and operation parameters of each link of the links associated with the APs 3221 and 3222.

[0105] In some embodiments, at least one of the MLD upper MAC sublayer functional entity 310 and the SME can be configured to: determine whether the first MLD middle MAC sublayer functional entity 321 is qualified based on the capability information and operation parameters. If the first MLD middle MAC sublayer functional entity 321 is qualified, at least one of the MLD upper MAC sublayer functional entity 310 and the SME can be configured to: activate the first MLD middle MAC sublayer functional entity 321 and the APs 3221 and 3222 for MLO based on the capability information and operation parameters. After activation, at least one of the MLD upper MAC sublayer functional entity 310 and the SME can be configured to: manage the links associated with the APs 3221 and 3222 (e.g., enable or disable the links) like a traditional AP.

[0106] On the other hand, if the first MLD middle MAC sublayer functional entity 321 is unqualified, at least one of the MLD upper MAC sublayer functional entity 310 and the SME can be configured to: deactivate the first MLD middle MAC sublayer functional entity 321 and the APs 3221 and 3222 for MLO based on the capability information and operation parameters.

[0107] In some embodiments, the logical port 323 can be configured to: implement a transport protocol for exchanging information between the MLD upper MAC sublayer functional entity 310 and the first MLD middle MAC sublayer functional entity 321. The information can include at least one of the following: management information, control information, configuration information, or data information.

[0108] In some embodiments, the information exchange between the MLD upper MAC sublayer functional entities 310 can be performed through the logical port 323 and the logical port 312 in the MLD upper MAC sublayer functional entity 310.

[0109] In some embodiments, the first MLD middle MAC sublayer functional entity 321 can be configured to: cache the MPDUs from the MLD upper MAC sublayer functional entity 310 for transmission or retransmission within the physical device 320.

[0110] In some embodiments, the MLD upper MAC sublayer functional entity 310 may not be configured to locally cache MPDUs. In such embodiments, the first MLD intermediate MAC sublayer functional entity 321 may be configured to: provide the cached MPDUs to the MLD upper MAC sublayer functional entity 310 for transmission or retransmission across physical devices 320 and 330.

[0111] In some embodiments, the first MLD intermediate MAC sublayer functional entity 321 may be configured to select one or more of the links 3221 and 3222 for transmission or retransmission of the cached MPDUs based on at least one of the following:

[0112] · The establishment status of the links associated with APs 3221 and 3222,

[0113] · The link indication in the MPDU,

[0114] · The TID of the MPDU,

[0115] · The caching status of the TID on the links associated with APs 3221 and 3222,

[0116] · The queue status of the TID on the links associated with APs 3221 and 3222, or

[0117] · The TID-to-link mapping obtained from the MLD upper MAC sublayer functional entity 310.

[0118] In some embodiments, the first MLD intermediate MAC sublayer functional entity 321 may be configured to: obtain the block Ack status of the MPDU from link 3221 and provide the block Ack status to link 3222 for retransmission of the MPDU via link 3222.

[0119] In some embodiments, the first MLD intermediate MAC sublayer functional entity 321 may be configured to: provide the block Ack status to the MLD upper MAC sublayer functional entity 310.

[0120] In some embodiments, each of the MLD lower MAC sublayer functional entities of APs 3221 and 3222 may be configured to: implement most of the functions of the lower MAC sublayer 220 in the legacy AP MLD 120 and make minor enhancements. For example, each of the MLD lower MAC sublayer functional entities of APs 3221 and 3222 may be configured to: cooperate with the first MLD intermediate MAC sublayer functional entity 321 to maintain the block Ack status.

[0121] It should be understood that the functions of the MLD middle MAC sublayer functional entities have been described by taking the first MLD middle MAC sublayer functional entity 321 as an example. The second MLD middle MAC sublayer functional entity 331 may have the same functions as the first MLD middle MAC sublayer functional entity 321. For the sake of brevity, the details of the functions of the second MLD middle MAC sublayer functional entity 331 are omitted.

[0122] Similarly, the MLD lower MAC sublayer functional entities of AP 3321 and AP 3322 may have the same functions as the MLD lower MAC sublayer functional entities of AP 3221 and AP 3222. For the sake of brevity, the details of the functions of the MLD lower MAC sublayer functional entities of AP 3321 and AP 3322 are omitted.

[0123] Figure 4 An example of the data plane architecture 400 of the MAC layer of the distributed AP MLD 300 according to some example implementations of the present disclosure is illustrated.

[0124] As Figure 4 shown, the distributed AP MLD 300 includes an MLD upper MAC sublayer functional entity 310, a first MLD middle MAC sublayer functional entity 321, a second MLD middle MAC sublayer functional entity 331, a non-MLD upper MAC sublayer functional entity 350, and a non-MLD upper MAC sublayer functional entity 360.

[0125] In addition, the distributed AP MLD 300 further includes an IEEE 802.1X controlled and uncontrolled port filtering port 340. The IEEE 802.1X controlled and uncontrolled port filtering port 340 includes an IEEE 802.1X controlled port (C) 341 and an IEEE 802.1X uncontrolled port (U) 342. The IEEE 802.1X controlled and uncontrolled port 340 communicates with the MLD upper MAC sublayer 310 through a single MAC-SAP 343. The functions of the IEEE 802.1X controlled and uncontrolled port filtering port 340 are the same as those of Figure 2 the IEEE 802.1X control and uncontrolled port filtering port 230 in. Therefore, for the sake of brevity, the details of the functions are omitted.

[0126] The upper MLD MAC sublayer 310 includes: an RX / TX MSDU rate limiting block 3111, an A-MSDU aggregation or de-aggregation block 3112, a PS deferral queuing block 3113, a sequence number (SN) assignment block 3114, a packet number (PN) assignment block 3115, an MPDU encryption block 3116, a replay detection block 3117 (which is optional), a block acknowledgement (Ack) caching and reordering block 3118, an MPDU decryption block 3119, a duplicate detection block 3120, and a traffic identifier (TID) to link mapping or merging block 3121.

[0127] The functions of blocks 3111 to 3117, 3119, and 3120 are the same as those of blocks 2111 to 2117, 2119, and 2120 in Figure 2 . For the sake of brevity, the details of the functions of blocks 3111 to 3117, 3119, and 3120 are omitted.

[0128] The first MLD middle MAC sublayer 321 includes: an MPDU caching block 3210, and a block Ack scoring block 3211.

[0129] The MPDU caching block 3210 can be configured to cache MPDUs from the MLD upper MAC sublayer functional entity 310 for transmission or retransmission within the physical device 320.

[0130] The lower MLD MAC sublayer of the AP 3221 includes a block Ack scoring block 3221-1, an address archival block 3221-2, an MPDU header and CRC creation or verification block 3221-3, and an A-MSDU aggregation or de-aggregation block 3221-4. The functions of blocks 3221-2 to 3221-4 are the same as those of blocks 2211-2213. For the sake of brevity, the details of the functions of blocks 3221-2 to 3221-4 are omitted.

[0131] The lower MLD MAC sublayer of the AP 3222 includes a block Ack scoring block 3222-1, an address archival block 3222-2, an MPDU header and CRC creation or verification block 3222-3, and an A-MSDU aggregation or de-aggregation block 3222-4. The functions of blocks 3222-2 to 3222-4 are the same as those of blocks 2211 to 2213. For the sake of brevity, the details of the functions of blocks 3222-2 to 3222-4 are omitted.

[0132] The second MLD middle MAC sublayer 331 includes: an MPDU caching block 3310, and a block Ack scoring block 3311.

[0133] The MPDU caching block 3310 can be configured to cache MPDUs from the MLD upper MAC sublayer functional entity 310 for transmission or retransmission within the physical device 330.

[0134] The lower MLD MAC sublayer of AP 3321 includes: a block Ack scoring block 3321-1, an address filing block 3321-2, an MPDU header and CRC creation or verification block 3321-3, and an A-MSDU aggregation or deaggregation block 3321-4. The functions of blocks 3321-2 to 3321-4 are the same as those of blocks 2211-2213. For the sake of brevity, the details of the functions of blocks 3321-2 to 3321-4 are omitted.

[0135] The lower MLD MAC sublayer of AP 3322 includes: a block Ack scoring block 3322-1, an address filing block 3322-2, an MPDU header and CRC creation or verification block 3322-3, and an A-MSDU aggregation or deaggregation block 3322-4. The functions of blocks 3322-2 to 3322-4 are the same as those of blocks 2211 to 2213. For the sake of brevity, the details of the functions of blocks 3322-2 to 3322-4 are omitted.

[0136] In some embodiments, during transmission, the MSDU from MAC-SAP 343 goes through Figure 4 the process shown in the left side.

[0137] The upper MAC sublayer functional entity 310 is configured to forward the MPDU downward to one of the MLD middle MAC sublayer functional entities 321 and 331 through a TID-to-link mapping process. Hereinafter, some embodiments will be described by taking the MLD middle MAC sublayer functional entity 321 as an example.

[0138] Based on the implementation of the MLD middle MAC sublayer functional entity 321, in some embodiments, the MLD middle MAC sublayer functional entity 321 can forward the MPDU from the MLD upper MAC sublayer functional entity 310 downward to one of the lower MLD MAC sublayer functional entities of AP 3221 and AP 3222 through an additional TID-to-link mapping process. In other embodiments, the MLD middle MAC sublayer functional entity 321 can directly forward the MPDU downward to one of the lower MLD MAC sublayer functional entities of AP 3221 and AP 3222, as shown by the MPDU.

[0139] When receiving the MPDU, the lower MLD MAC sublayer functional entity of AP 3221 or AP 3222 can deliver the MPDU to the corresponding PHY SAP after some processing (such as address filtering or MPDU aggregation).

[0140] In some embodiments, during reception, MPDUs originating from different PHY SAPs first pass through the MLD lower MAC sublayer functional entities of AP 3221 or AP 3222, and then the TID-to-link mapping or the merging process in the merging block 3121 in the MLD upper MAC sublayer functional entity 310. Then, the MPDU will pass through Figure 4 the process on the right side. One or more MSDUs are delivered to the MAC-SAP 343 or to the DS via the DSAF.

[0141] In some embodiments, optionally, the reception of MPDUs may be transparent to the MLD middle MAC sublayer functional entities 321 and 331.

[0142] In some embodiments, block Ack scoring may be maintained for each of the following: the MLD upper MAC sublayer functional entity 310 of AP 3221 and AP 3222, the MLD middle MAC sublayer functional entities 321 and 331, and the MLD lower MAC sublayer functional entity.

[0143] In some embodiments, the block Ack scoring block 3118 in the MLD upper MAC sublayer functional entity 310 manages the block Ack status of MPDUs of a block Ack session received on any established link. The MLD upper MAC sublayer functional entity 310 may receive the block Ack status of MPDUs from its subordinate MLD middle MAC sublayer functional entities 321 and 331.

[0144] In some embodiments, in cooperation with the MLD lower MAC sublayer functional entities of AP 3221 and AP 3222, the block Ack scoring block 3221-1 in the MLD middle MAC sublayer functional entity 321 is configured to manage the block Ack status of MPDUs of a block Ack session received on any subordinate established link. The MLD middle MAC sublayer functional entity 321 in the physical device 320 may receive the block Ack status of MPDUs from its subordinate MLD lower MAC sublayer functional entities of AP3221 and AP 3222 or from the physical device 330.

[0145] In some embodiments, the block Ack scoring block 3221-1 in the MLD lower MAC sublayer functional entity of AP 3221 is configured to: manage the block Ack status of MPDUs of a block Ack session received on that link. The MLD lower MAC sublayer functional entity of AP3221 associated with one link may receive the block Ack status of MPDUs from another link attached to the physical device 320.

[0146] In some embodiments, the retransmission of MPDUs may be performed as follows.

[0147] In one embodiment, if a NACK for the transmission of an MPDU is received on the established link associated with the MLD lower MAC sublayer functional entity of the AP 3221, the MLD lower MAC sublayer functional entity in the AP 3221 may retransmit the MPDU on the established link based on the content in the block Ack scoreboard 3221-1.

[0148] In another embodiment, the MLD middle MAC sublayer functional entity 321 may schedule the retransmission of the MPDU across the links affiliated with the physical device 320 based on the content in the block Ack scoreboard 3211.

[0149] In another embodiment, the MLD upper MAC sublayer functional entity 310 may schedule the retransmission of the MPDU across the physical devices 320 and 330 based on the content in the block Ack scoreboard 3118.

[0150] For the data plane architecture 400, the distributed AP MLD 300 may send non-MLD data frames through a dedicated non-MLD upper sublayer functional entity of the affiliated AP (such as the AP 3221). The non-MLD upper sublayer functional entity is connected to the MLD middle MAC sublayer functional entity 321 affiliated by the AP through a logical port. The MLD middle MAC sublayer functional entity 321 may schedule the non-MLD data frames to be sent through the corresponding link of the affiliated AP.

[0151] When the distributed AP MLD 330 receives a non-MLD data packet on the link, the MLD lower MAC sublayer functional entity associated with the link may decode the data packet and forward the corresponding MPDU to the MLD middle MAC sublayer functional entity (e.g., the MLD middle MAC sublayer functional entity 321). Thereafter, the MLD middle MAC sublayer functional entity 321 may send the received MPDU to the non-MLD MAC sublayer functional entity 350 of the link for further processing.

[0152] Figure 5 An example of the MLO between the distributed AP MLD 300 and the non-AP MLD 500 according to some example implementations of the present disclosure is illustrated.

[0153] As Figure 5 shown, the distributed AP MLD 300 includes: an MLD upper MAC sublayer functional entity 310, a first MLD middle MAC sublayer functional entity 321, and a second MLD middle MAC sublayer functional entity 331. Since the non-MLD upper MAC sublayer functional entities 350 and 360 are not relevant to the MLO, the entities 350 and 360 are not shown in Figure 5 herein.

[0154] Reference Figure 3 and Figure 4 The embodiments of the described entities 310, 321, and 331 are also applicable to Figure 5 the distributed AP MLD 300 in . For the sake of brevity, the details of the embodiments are omitted.

[0155] The non-AP MLD 500 includes: a traditional MLD upper MAC sublayer functional entity 510, and a traditional MLD lower MAC sublayer functional entity 520. The traditional MLD lower MAC sublayer functional entity 520 is attached to STAs 521, 522, and 523.

[0156] In this example, the distributed AP MLD 300 is configured with an MLD MAC address M, and the non-AP MLD is configured with an MLD MAC address N.

[0157] After multi-link establishment, three links are established between the non-AP MLD 500 and the distributed AP MLD 300. That is, link 1 is established between AP 3221 and non-AP STA 521, link 2 is established between AP 3222 and non-AP STA 522, and link 3 is established between AP 3322 and non-AP STA 523. The distributed AP MLD 300 can increase the throughput of the non-AP MLD 500 by aggregating the three links associated with physical devices 320 and 330.

[0158] Figure 6 is a simplified block diagram of a device 600 suitable for implementing the embodiments of the present disclosure. The device 600 can be provided to implement a communication device, for example, such as Figure 3 the apparatus 300 shown. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0159] The communication module 640 is configured for two-way communication. The communication module 640 has at least one antenna to facilitate communication. The communication interface can represent any interface required for communication with other network elements.

[0160] The processor 610 can be of any type suitable for a local technical network, and as a non-limiting example, can include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 600 can have multiple processors, such as an application-specific integrated circuit chip that is subordinate in time to a clock synchronized with the main processor.

[0161] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 624, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic storage devices and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 622 and other volatile memories that do not persist during a power outage.

[0162] The computer program 630 includes computer-executable instructions that are executed by the associated processor 610. The instructions (e.g., the computer program 630) may be stored in the memory 620 (e.g., ROM 624). The processor 610 may execute any suitable actions and processes by loading the program 630 into the RAM 622.

[0163] Embodiments of the present disclosure may be implemented by instructions (e.g., the computer program 630) such that the device 600 may perform any of the processes of the present disclosure discussed with reference to Figures 3 to 5 Embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0164] In some example embodiments, the program 630 may be tangibly embodied in a computer-readable medium, which may be included in the device 600 (such as in the memory 620) or in other storage devices accessible to the device 600. The device 600 may load the program 630 from the computer-readable medium into the RAM 622 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Figure 7 An example of a computer-readable medium 700 in the form of a CD or DVD is shown. The program 630 is stored on the computer-readable medium.

[0165] Generally, the various embodiments of the present disclosure may be implemented using hardware or special-purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented using hardware, while other aspects may be implemented using firmware or software that may be executed by a controller, microprocessor, or other computing device. Although the various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as a non-limiting example, the blocks, devices, systems, techniques, or methods described herein may be implemented using hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or a controller or other computing device, or some combination thereof.

[0166] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as the instructions included in program modules, which are executed in a device on a target real or virtual processor for the device to perform the methods described above with reference to Figure 3 and Figure 4 the methods described. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of program modules can be combined or split as needed among program modules. The machine-executable instructions of program modules can be executed within a local or distributed device. In a distributed device, program modules can be located in both local and remote storage media.

[0167] The program code for performing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0168] In the context of the present disclosure, the computer program code or related data can be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0169] The computer-readable media can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium will include an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0170] Moreover, although the operations are described in a particular order, this should not be construed as requiring that such operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Also, although several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0171] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the above specific features and acts are disclosed as example forms of implementing the claims.

[0172] List of Abbreviations

[0173] A-MPDU: Aggregation of MAC data units

[0174] AP: Access Point

[0175] AR: Augmented Reality

[0176] BIGTK: Beacon Integrity Group Temporary Key

[0177] CTS: Clear to Send

[0178] DS: Distributed System

[0179] DSAF: Distributed System Access Function

[0180] GTK: Group Temporary Key

[0181] IGTK: Integrity Group Temporary Key

[0182] LLC: Logical Link Control

[0183] MAC: Media Access Control

[0184] MLD: Multi-Link Device

[0185] MLO: Multi-Link Operation

[0186] MPDU: MAC Protocol Data Unit

[0187] NDP: Null Data Packet

[0188] RTS: Request to Send

[0189] RX: Receiver

[0190] SAP: Service Access Point

[0191] MSDU: MAC Service Data Unit

[0192] SN: Serial Number

[0193] SME: Station Management Entity

[0194] STA: Station

[0195] Tx: Transceiver

[0196] PMK: Pairwise Master Key

[0197] PMKSA: Pairwise Master Key Security Association

[0198] PN: Packet Number

[0199] PTKSA: Pairwise Transient Key Security Association

[0200] TID: Traffic Identifier

[0201] VR: Virtual Reality

[0202] XR: Extended Reality

Claims

1. A device, comprising: at least two upper Medium Access Control (MAC) sublayer functional entities; and at least one intermediate MAC sublayer functional entity, configured to be attached to at least one Access Point (AP) having a lower MAC sublayer functional entity, wherein the at least one intermediate MAC sublayer functional entity is configured to communicate with the at least two upper MAC sublayer functional entities via a logical port.

2. The device according to claim 1, wherein the at least two upper MAC sublayer functional entities include a Multi-Link Device (MLD) upper MAC sublayer functional entity and at least one non-MLD upper MAC sublayer functional entity.

3. The device according to claim 1, wherein the at least one non-MLD upper MAC sublayer functional entity comprises: a first non-MLD upper MAC sublayer functional entity configured to be associated with a first AP and a first lower MAC sublayer functional entity of the first AP, the first AP being attached to a first intermediate MAC sublayer functional entity.

4. The device according to claim 3, wherein the first non-MLD upper MAC sublayer functional entity is configured to communicate with the first lower MAC sublayer functional entity via the logical port using a tunnel transparent to the at least one intermediate MAC sublayer functional entity.

5. The device according to claim 2, wherein the MLD upper MAC sublayer functional entity is configured to: select one of the at least one intermediate MAC sublayer functional entities for transmission or retransmission of traffic having the Traffic Identifier (TID) based on at least one of: TID-to-link mapping or the queue state of the TID.

6. The device according to claim 2, wherein the intermediate MAC sublayer functional entities include a first intermediate MAC sublayer functional entity and a second intermediate MAC sublayer functional entity, the first intermediate MAC sublayer functional entity being configured to be attached to at least one first AP, and the second intermediate MAC sublayer functional entity being configured to be attached to at least one second AP; and wherein the first intermediate MAC sublayer functional entity and the at least one first AP are deployed in a first physical device, and the second intermediate MAC sublayer functional entity and the at least one second AP are deployed in a second physical device different from the first physical device, the first physical device and the second physical device being included in the device.

7. The device according to claim 6, wherein the MLD upper MAC sublayer functional entity is configured to: obtain the block acknowledgment status of a MAC Protocol Data Unit (MPDU) from the first intermediate MAC sublayer functional entity; and schedule retransmission of the MPDU across the at least one intermediate MAC sublayer functional entity based on the block acknowledgment status.

8. The device according to claim 7, wherein the MLD upper MAC sublayer functional entity is further configured to: provide the block acknowledgment status to the second intermediate MAC sublayer functional entity.

9. The apparatus according to claim 6, wherein each of the at least one first AP is configured to operate on a link.

10. The apparatus according to claim 9, wherein the first intermediate MAC sublayer functional entity is configured to provide the MLD upper MAC sublayer functional entity with the capability information and operation parameters of each of the at least one link; and the MLD upper MAC sublayer functional entity is configured to perform at least one of the following: activate the first intermediate MAC sublayer functional entity and the at least one first AP for multi-link operation based on the capability information and the operation parameters, deactivate the first intermediate MAC sublayer functional entity and the at least one first AP for the multi-link operation based on the capability information and the operation parameters, or manage the first intermediate MAC sublayer functional entity and the at least one first AP for the multi-link operation based on the capability information and the operation parameters.

11. The apparatus according to claim 9, wherein the first intermediate MAC sublayer functional entity is configured to provide the station management entity SME with the capability information and operation parameters of each of the at least one link; and the SME is configured to perform at least one of the following: activate the first intermediate MAC sublayer functional entity and the at least one first AP for multi-link operation based on the capability information and the operation parameters, deactivate the first intermediate MAC sublayer functional entity and the at least one first AP for the multi-link operation based on the capability information and the operation parameters, or manage the first intermediate MAC sublayer functional entity and the at least one first AP for the multi-link operation based on the capability information and the operation parameters.

12. The apparatus according to claim 10, wherein the at least two upper MAC sublayer functional entities and the SME are implemented in at least one of the first physical device and the second physical device.

13. The apparatus according to claim 10, wherein the at least two upper MAC sublayer functional entities and the SME are implemented in a third physical device different from the first physical device and the second physical device, and the third physical device is included in the apparatus.

14. The apparatus according to claim 9, wherein the first intermediate MAC sublayer functional entity is configured to: select one or more links from the at least one link for the transmission or retransmission of the MAC protocol data unit MPDU based on at least one of the following: the establishment state of the at least one link, the link indication in the MPDU, the traffic identifier TID of the MPDU, the caching state of the TID on the at least one link, the queue state of the TID on the at least one link, or the TID-to-link mapping obtained from the MLD upper MAC sublayer functional entity.

15. The apparatus according to claim 9, wherein the first intermediate MAC sublayer functional entity is configured to: Obtain the block acknowledgment status of a MAC protocol data unit (MPDU) from a first link; and Provide the block acknowledgment status to a second link for retransmission of the MPDU over the second link.

16. The apparatus according to claim 15, wherein the first intermediate MAC sublayer functional entity is further configured to: Provide the block acknowledgment status to the upper MLD MAC sublayer functional entity.

17. The apparatus according to claim 2, wherein the at least one intermediate MAC sublayer functional entity is configured to: Cache a MAC protocol data unit (MPDU) from the upper MLD MAC sublayer functional entity for transmission or retransmission within the at least one intermediate MAC sublayer functional entity.

18. The apparatus according to claim 17, wherein the at least one intermediate MAC sublayer functional entity is further configured to: Provide the cached MPDU to the upper MLD MAC sublayer functional entity for transmission or retransmission across the at least one intermediate MAC sublayer functional entity.

19. The apparatus according to claim 1, wherein the at least two upper MAC sublayer functional entities and the at least one intermediate MAC sublayer functional entity are implemented in a single physical device, and the single physical device is included in the apparatus.

20. The apparatus according to claim 1, wherein the at least two upper MAC sublayer functional entities are implemented in a third physical device, and the at least one intermediate MAC sublayer functional entity is implemented in a fourth physical device different from the third physical device, and the third physical device and the fourth physical device are included in the apparatus.

21. The apparatus according to claim 20, wherein at least one of the third physical device and the fourth physical device is pluggable.

22. An apparatus comprising: Components for implementing at least two upper media access control (MAC) sublayer functional entities; and Components for implementing at least one intermediate MAC sublayer functional entity, the at least one intermediate MAC sublayer functional entity being configured to be attached to at least one access point (AP) having a lower MAC sublayer functional entity, wherein the at least one intermediate MAC sublayer functional entity is configured to communicate with the at least two upper MAC sublayer functional entities via a logical port.

23. A method comprising: Implementing at least two upper media access control (MAC) sublayer functional entities; and Attaching at least one intermediate MAC sublayer functional entity to at least one access point (AP) having a lower MAC sublayer functional entity, wherein the at least one intermediate MAC sublayer functional entity communicates with the at least two upper MAC sublayer functional entities via a logical port.

24. An apparatus comprising: At least one processor; and At least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: Implement at least two upper media access control (MAC) sublayer functional entities; and Attach at least one intermediate MAC sublayer functional entity to at least one access point AP having a lower MAC sublayer functional entity, wherein the at least one intermediate MAC sublayer functional entity communicates with the at least two upper MAC sublayer functional entities via a logical port.

25. A computer-readable medium comprising program instructions for causing a device to perform the method according to claim 23.

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