Apparatus and method for coordinated transmissions in wireless network

Abstract

There is disclosed an access point (AP) (120) for obtaining channel access by participating in coordinated transmission with at least a portion of at least one transmission opportunity (TXOP) acquired and shared by an AP (110) operating as a shared AP (110), the AP (110) operating under a coordinated protocol of a wireless communication network (100) and / or within a set (125) of multiple APs (multi-AP, M-AP), the wireless communication network (100) further comprises one or more first further APs (130, 140) operating as part of the set of M-APs (125) and / or under the same coordination protocol. The AP (120) is configured to implement one or more fairness timers, the one or more fairness timers comprising a first fairness timer and / or a second fairness timer, for ensuring channel access fairness between the AP (120) and other APs (110, 130, 140), the other APs (110, 130, 140) operating under the same coordination protocol within the same set of M-APs (125).

Description

Technical Field

[0001] This invention relates to wireless communication. More specifically, this invention relates to apparatus and methods for coordinated transmission in wireless communication networks, particularly WLANs based on IEEE 802.11. Background Technology

[0002] WLANs (also known as Wi-Fi networks) based on IEEE 802.11 have proliferated at an unprecedented rate. Modification IEEE 802.11be introduced multi-AP (M-AP) coordinated transmission operations, in which multiple access points (APs) share resources to support coordinated transmission and more efficiently utilize their resources to communicate with non-AP stations (STAs). The main principle of M-AP coordination is that an AP that acquires a transmission opportunity (TXOP) can share its resources with other APs. The group of APs that have decided to cooperate and perform coordinated transmissions can be a subset of the M-AP set. APs sharing TXOPs are also called APs operating as shared APs (or simply "shared APs"), while other APs using the TXOPs shared by the shared APs to participate in coordinated transmissions are also called APs operating as shared APs (or simply "shared APs").

[0003] In Wi-Fi networks, each access point (AP) or non-AP station must maintain a backoff counter (also known as an enhanced distributed channel access (EDCA) backoff counter). This backoff counter allows the AP or non-AP station to determine whether it should acquire an EDCA TXOP to initiate a frame exchange sequence. A set of EDCA channel access rules defined by the IEEE 802.11 standard defines: conditions for setting the backoff counter to a value; conditions for decrementing the backoff counter; and conditions for acquiring an EDCA TXOP. Assuming all EDCA channel access rules are maintained by each AP in the Wi-Fi network, APs participating in coordinated transmission gain channel access while their EDCA backoff counters remain unchanged. This can lead to unfairness in Wi-Fi networks for APs that do not support M-AP coordinated transmission, as APs participating in M-AP coordinated transmission may have more channel access compared to APs that do not participate in M-AP coordinated transmission. Summary of the Invention

[0004] The aim is to provide improved devices and methods for AP coordinated transmission in wireless communication networks, specifically IEEE 802.11-based WLANs, while maintaining fairness in channel access.

[0005] The foregoing and other objectives are achieved through the subject matter claimed in the independent claims. Other implementations are apparent from the dependent claims, the specification, and the drawings.

[0006] According to a first aspect, an access point (AP) is provided for obtaining channel access by participating in coordinated transmission using at least a portion of at least one transmission opportunity (TXOP) acquired and shared by a shared AP (i.e., an AP operating as a shared AP), wherein the AP and the shared AP operate under a coordination protocol of a wireless, specifically Wi-Fi, communication network and / or within a multi-AP (M-AP) set, the Wi-Fi communication network further including one or more first additional APs operating under the same coordination protocol and / or as part of the M-AP set. The AP is used to implement one or more fairness timers, including: a first fairness timer (also referred to herein as M-APInterSetTimer) for ensuring channel access fairness between the AP and one or more second additional APs operating on the same channel but not part of the M-AP set or the same coordination protocol or another coordination protocol; and / or a second fairness timer (also referred to herein as M-APIntraSetTimer) for ensuring channel access fairness between the AP and the first additional AP, operating under the same coordination protocol and / or as part of the same M-AP set. Therefore, the AP is provided for use in wireless communication networks, specifically for coordinated transmissions in IEEE 802.11-based WLANs, to support the maintenance of channel access fairness and thus reduce collision rates in wireless communication networks.

[0007] In another possible implementation, the AP is configured to implement the first fairness timer after being shared by the APs operating as the shared AP for coordinating transmissions, the AP having acquired the TXOP to ensure channel access fairness between the AP and the one or more second additional APs operating on the same channel but not part of the M-AP set or the same coordination protocol or another coordination protocol, and the AP is configured to wait for the first fairness timer to end (i.e. expire) before resuming competition for the channel access.

[0008] In another possible implementation, the AP is used to wait for the first fairness timer to expire (i.e., to expire) before resuming contention for channel access by restoring the EDCA backoff counter.

[0009] In another possible implementation, the first fairness timer is defined in units of time.

[0010] In another possible implementation, the AP is configured to implement the second timer to ensure channel access fairness between the AP and the first additional AP, which is shared by the AP operating as the shared AP, operating under the same coordination protocol and / or as part of the M-AP set, wherein the AP is configured to wait for the second timer to expire (i.e., to expire) before participating in another subsequent M-AP coordinated transmission within the M-AP set or under the same coordination protocol within the M-AP set.

[0011] In another possible implementation, the second timer is defined in units of time.

[0012] In another possible implementation, the second timer is defined in units of TXOP.

[0013] In another possible implementation, the AP is used to count down the second timer, defined in units of TXOP, by decrementing the second timer by one whenever the TXOP is held by one or more of the first additional APs, the first additional APs operating in the M-AP set or under the same coordination protocol within the M-AP set.

[0014] In another possible implementation, the AP is used to start the first timer and / or the second timer when the TXOP ends.

[0015] In another possible implementation, the AP is configured to receive a PPDU from the AP operating as the shared AP (i.e., the AP that has already acquired the TXOP), wherein the PPDU includes an indication of the duration of the TXOP, specifically a duration field value, to start the first timer and / or the second timer.

[0016] In another possible implementation, the AP is used to be triggered by the AP operating as the shared AP (i.e., the AP that has acquired the TXOP) to send at least one PPDU as a coordinated transmission, wherein the AP is used to start the first timer and / or the second timer when the at least one PPDU ends.

[0017] In another possible implementation, the AP is configured to restart the first timer and / or the second timer if the AP is triggered by the AP operating as the shared AP (i.e., the AP that has acquired the TXOP) to send at least one additional PPDU as a coordinated transmission.

[0018] In another possible implementation, the AP is configured to receive a frame from the AP operating as the shared AP, wherein the frame instructs the AP to start the first timer and / or the second timer at the end of the frame.

[0019] In another possible implementation, the frame includes one or more identifiers indicating that one or more of the APs and / or the first additional APs operating under the same coordination protocol in the M-AP set are requested and / or required to start the first timer and / or the second timer at the end of the frame.

[0020] In another possible implementation, the first timer and / or the second timer are defined by the coordination protocol upon which the AP operates.

[0021] In another possible implementation, before or at the start of the TXOP, the AP receives a frame from the AP operating as the shared AP (i.e., the AP that has already acquired the TXOP), wherein the frame includes an indication indicating whether the AP counts the second timer (i.e., whether the second timer is applied) before participating in another subsequent M-AP coordination transmission initiated by any AP operating within the same M-AP set or the same M-AP set as the AP. In one implementation, the indication may be a single bit, such as a flag bit, which may be part of the M-AP notification frame sent by the AP operating as the shared AP at the start of the TXOP acquired by the AP operating as the shared AP.

[0022] In another possible implementation, the ratio between the values ​​of the first timer and the second timer, or the ratio between the values ​​of the second timer and the first timer, is defined by a fairness factor.

[0023] In another possible implementation, the fairness factor is 1 or greater, or the fairness parameter is in the range of 0 to 1, i.e., including boundary values ​​of 0 and 1.

[0024] In another possible implementation, the AP is configured to receive frames containing M-AP EDCA information elements from the AP operating as the shared AP within the same M-AP set, wherein the M-AP EDCA information elements include one or more parameters, the one or more parameters including: a first timer; a second timer; the fairness factor; the minimum size of the M-AP contention window; the maximum size of the M-AP contention window; the M-AP arbitration interframe space number (AIFSN); and / or the timer initialization point.

[0025] In another possible implementation, the AP is used to derive the M-AP EDCA information element as a component of the frame containing the coordination protocol, and the frame is sent by the AP operating as the shared AP, wherein one or more parameters of the M-AP information element are valid for the duration of the coordination protocol.

[0026] In another possible implementation, the AP is used to derive the M-AP EDCA information element as a component of the M-AP notification frame, which is sent by the AP operating as the shared AP, wherein one or more parameters of the M-AP information element are valid for the current TXOP.

[0027] In another possible implementation, the AP is used to send information to the AP operating as the shared AP, which operates under the same coordination protocol within the M-AP set, the information indicating whether the second timer has expired, so that the AP operating as the shared AP knows the potential APs (as the shared AP) that may participate in the next M-AP coordination transmission.

[0028] In another possible implementation, the AP is configured to send an M-AP timer status response frame to the AP operating as the shared AP in response to receiving an M-AP timer status polling frame and / or an M-AP notification frame aggregated with the M-AP timer status polling frame sent by the AP operating as the shared AP. The AP operating as the shared AP operates under the same coordination protocol within the M-AP set, and the M-AP timer status response frame includes information indicating whether the second timer has expired.

[0029] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes an M-AP set identifier indicating the M-AP set.

[0030] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes a coordination protocol identifier within the M-AP set, wherein the coordination protocol identifier identifies one of a plurality of coordination protocols within the M-AP set, and the AP operates as the shared AP, the AP operating under the coordination protocol identified by the coordination protocol identifier within the M-AP set.

[0031] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes the identifier of the AP and / or one or more identifiers of the one or more first additional APs operating under the same coordination protocol in or within the M-AP set, the identifier indicating that the AP is requested to send an M-AP timer status response frame to the shared AP.

[0032] In another possible implementation, the AP is used to send the M-AP timer status response frame to the AP operating as the shared AP, which operates the same coordination protocol within the M-AP set, regardless of whether the first fairness timer and / or the second fairness timer has ended.

[0033] According to a second aspect, a method is provided for operating an access point (AP) for obtaining channel access by participating in coordinated transmission using at least a portion of at least one transmission opportunity (TXOP), the at least one TXOP being acquired and shared by an AP operating as a shared AP operating under a coordination protocol of a wireless, specifically Wi-Fi communication network and / or within a multi-AP (M-AP) set, the wireless, specifically Wi-Fi communication network further including one or more first additional APs operating as part of the M-AP set and / or under the coordination protocol, wherein the method includes implementing one or more fairness timers, the one or more fairness timers comprising: a first timer for ensuring channel access fairness between the AP and one or more second additional APs operating on the same channel but not as part of the M-AP set or the coordination protocol or another coordination protocol; and / or a second timer for ensuring channel access fairness between the AP and the one or more first additional APs operating under the same coordination protocol within the same M-AP set.

[0034] The method provided in the second aspect of the invention can be executed by the AP provided in the first aspect of the invention. Therefore, other features of the method provided in the second aspect of the invention are directly derived from the functionality of the AP provided in the first aspect of the invention and its various implementations described above and below.

[0035] According to a third aspect, an AP operating as a shared AP is provided, wherein the AP operating as the shared AP is used to utilize at least one transmission opportunity acquired and shared by the AP operating as the shared AP. At least a portion of the first additional AP (TXOP) participates in the coordination transmission to manage channel access for one or more other APs, the AP operating as the shared AP operating under a coordination protocol of a wireless, specifically Wi-Fi, communication network and / or within a multi-AP (M-AP) set, wherein each of the one or more first additional APs is configured to implement one or more fairness timers, the one or more fairness timers comprising: a first fairness timer for ensuring channel access fairness between the AP and one or more second additional APs operating on the same channel but not part of the M-AP set or the coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the AP and one or more first additional APs operating under the same coordination protocol within the same M-AP set, wherein the AP operating as the shared AP is configured to send M-AP timer status polling frames and / or M-AP notification frames aggregated with M-AP timer status polling frames to the one or more first additional APs to request information about the second fairness timer, such as the status of the second fairness timer.

[0036] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes an M-AP set identifier indicating the M-AP set.

[0037] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes a coordination protocol identifier within the M-AP set, wherein the coordination protocol identifier identifies one of a plurality of coordination protocols within the M-AP set, and the AP operates as the shared AP, and the one or more other APs operate under the coordination protocol identified by the coordination protocol identifier within the M-AP set.

[0038] In another possible implementation, the M-AP timer status polling frame and / or the M-AP notification frame includes one or more identifiers of the one or more first additional APs operating under the same coordination protocol in or within the M-AP set, the one or more identifiers indicating that the AP is requested to send an M-AP timer status response frame to the AP operating as the shared AP.

[0039] In another possible implementation, the AP acting as the shared AP is configured to receive an M-AP timer status response frame from the one or more first additional APs, wherein the M-AP timer status response frame includes information about the second fairness timer.

[0040] In another possible implementation, the AP operating as the shared AP is configured to send an indication to the one or more first additional APs, the indication being configured to set the second fairness timer of each of the one or more first additional APs to zero for the current TXOP.

[0041] In another possible implementation, the AP operating as the shared AP is configured to send an M-AP notification frame to the one or more first additional APs, wherein the M-AP notification frame includes the indication for setting the second timer of each of the one or more first additional APs to zero for the current TXOP.

[0042] In another possible implementation, the AP operating as the shared AP is used to send frames containing M-AP EDCA information elements to one or more first additional APs within the M-AP set, wherein the M-AP EDCA information elements include one or more parameters, the one or more parameters including: a first fairness timer; a second fairness timer; a fairness factor defined by the ratio between the first fairness timer and the second fairness timer; a minimum size of the M-AP contention window; a maximum size of the M-AP contention window; an M-AP arbitration interframe space number (AIFSN); and / or a fairness timer initialization point.

[0043] In another possible implementation, the AP operating as the shared AP is configured to generate a new backoff counter value based on the minimum and maximum size of the M-AP contention window once the AP operating as the shared AP has completed the M-AP coordinated transmission of at least one TXOP.

[0044] According to a fourth aspect, a method is provided for operating an AP as a shared AP, wherein the AP operating as the shared AP is configured to manage channel access of one or more first additional APs by participating in coordinated transmissions using at least a portion of at least one transmission opportunity (TXOP) acquired and shared by the AP operating as the shared AP, the AP operating as the shared AP operating under a coordination protocol of a wireless, specifically Wi-Fi, communication network and / or within a multi-AP (M-AP) set, wherein each of the one or more first additional APs is configured to implement one or more fairness timers, the one or more fairness timers comprising: a first fairness timer for ensuring channel access fairness between the first additional AP and one or more second additional APs operating on the same channel but not part of the M-AP set or the coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the corresponding first additional AP and other first additional APs operating under the same coordination protocol within the M-AP set. The method includes sending an M-AP timer status polling frame and / or an M-AP notification frame aggregated with the M-AP timer status polling frame to the one or more first additional APs to request information about the status of the second fairness timer.

[0045] The method provided in the fourth aspect of the present invention can be executed by an AP operating as a shared AP, as provided in the third aspect of the present invention. Therefore, other features of the method provided in the fourth aspect of the present invention are directly derived from the functionality of the AP operating as a shared AP provided in the third aspect of the present invention and its various implementations described above and below.

[0046] According to a fifth aspect, a computer program product including a computer-readable storage medium is provided, the computer-readable storage medium being used to store program code that, when executed by a computer or processor, causes the computer or processor to perform the method of the second aspect or the method of the fourth aspect.

[0047] One or more embodiments will be described in detail in the accompanying drawings and the following description. Other features, objects, and advantages will be apparent from the specification, drawings, and claims. Attached Figure Description

[0048] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0049] Figure 1A schematic diagram of an exemplary wireless communication network provided in the embodiment is shown. The exemplary wireless communication network includes a shared AP and multiple shared APs under a coordination protocol in an M-AP set or the same M-AP set for M-AP coordination transmission, as well as multiple APs that are not part of the M-AP set or are not under the same M-AP set under a coordination protocol, to implement one or more channel access fairness timers. Figure 2 An embodiment is shown that utilizes a channel access fairness timer. Figure 1 A timing diagram of coordinated transmission of several APs in a wireless communication network for three transmission opportunities. Figure 3 An embodiment is shown, Figure 1 A timing diagram of frame exchange between several access points (APs) in a wireless communication network for obtaining information about one or more channel access fairness timers; Figure 4 A flowchart provided by an embodiment is shown, illustrating a method by which a shared AP operates as a shared AP in an M-AP coordination transport, the shared AP operating under the same coordination protocol within the M-AP set; Figure 5 This is a flowchart of a method for operating as a shared AP, as provided in the embodiment; Figure 6 This is a graph illustrating the channel access ratio of a group of APs implementing one or more channel access fairness timers according to an embodiment; Figure 7 A graph showing the cumulative distribution function (CDF) of the collision rate of a set of APs implementing one or more channel access fairness timers provided in the embodiment is shown. Figure 8 This is a graph illustrating the channel access ratio of a group of APs implementing one or more channel access fairness timers according to an embodiment.

[0050] In the following text, the same reference numerals refer to the same or at least functionally equivalent features. Detailed Implementation

[0051] In the following description, reference is made to the accompanying drawings, which form part of this invention and illustrate specific aspects of embodiments of the invention or to the drawings in which specific aspects of embodiments of the invention may be used. It should be understood that embodiments of the invention may be used in other aspects and may include structural or logical variations not depicted in the drawings. Therefore, the following detailed description should not be construed in a limiting sense, and the scope of the invention is defined by the appended claims.

[0052] For example, it should be understood that the disclosure relating to the described method can also apply to the corresponding device or system for performing the method, and vice versa. For example, if one or more specific method steps are described, the corresponding device may include one or more units (e.g., functional units) to perform the described one or more method steps (e.g., one unit performs one or more steps, or multiple units perform one or more of multiple steps respectively), even if the one or more units are not explicitly described or illustrated in the drawings. On the other hand, for example, if a specific apparatus is described based on one or more units (e.g., functional units), the corresponding method may include a step to perform the function of one or more units (e.g., one step performs the function of one or more units, or multiple steps perform the function of one or more of multiple units respectively), even if the one or more steps are not explicitly described or shown in the drawings. Furthermore, it should be understood that, unless otherwise expressly stated, features of the various exemplary embodiments and / or aspects described herein can be combined with each other.

[0053] Figure 1 An exemplary wireless communication network 100 is shown, comprising multiple access points (APs) 110 to 170. Figure 1 The illustrated embodiment may be an example of an enterprise implementation where multiple APs 110 to 170 provide connectivity to multiple non-AP stations (also known as non-AP STAs). Figure 1 In the exemplary scenario, only two exemplary non-AP stations 180 and 190 are shown as examples of multiple non-AP stations (e.g., seven or more non-AP stations), which may include mobile phones, laptops, tablets, or other types of smart IoT devices. It should be understood that once a corresponding non-AP station is associated with a corresponding AP 110 to 170, each AP 110 to 170 can provide connectivity to multiple non-AP stations (e.g., non-AP stations 180 and 190). In one embodiment, the wireless communication network 100 is a WLAN (also referred to as Wi-Fi network 100) according to the IEEE 802.11 standard framework.

[0054] In the exemplary scenario, APs 110, 120, 130, and 140 are part of a multi-AP (i.e., M-AP) set 125 (as indicated by circles), while APs 150, 160, and 170 are not part of the M-AP set 125. The M-AP set has already been discussed in the context of M-AP coordinated transmission operations (e.g., Figure 1The concept of an M-AP set (125) is used where multiple APs share resources to support parallel transmissions and more efficiently utilize their resources to communicate with non-AP stations (STAs). The main principle of M-AP coordinated transmission is that APs that have acquired a transmission opportunity (TXOP) can share their resources with other OBSS APs to create a coordinated transmission among the OBSS APs. The group of APs that have decided to cooperate and perform coordinated transmissions can be a subset of the M-AP set. APs sharing a TXOP are also called APs operating as shared APs (or simply "shared APs"), while other APs using the TXOP shared by the shared APs to participate in coordinated transmissions are also called APs operating as shared APs (or simply "shared APs"). The M-AP set (i.e., the AP group) can determine one or more specific coordination protocols, which, for example, define a corresponding set of parameters for coordinated transmissions of the APs in the M-AP set.

[0055] In the following detailed description of the embodiments, AP 110 operates as a shared AP and will therefore be referred to as the AP operating as shared AP 110 (or simply "shared AP 110"), while AP 120 in the M-AP set 125 and one or more of the possible other APs 130, 140 operate as shared APs and will therefore be referred to as APs operating as shared APs 120, 130, 140 (or simply "shared APs"). However, it should be understood that while for the first TXOP AP 110 may be the AP operating as a shared AP, and for example, AP 120 may be the AP operating as a shared AP, for another TXOP these roles may be reversed; that is, AP 110 may be the AP operating as a shared AP, and AP 120 may be the AP operating as a shared AP, as follows: Figure 2 This is described in more detail within the context of the example shown. Therefore, it should be further understood that being a shared AP or a shared AP can be considered as different operating modes or roles that each AP in the M-AP set can temporarily assume. In other words, the same physical AP (e.g., AP 110 or AP 120) can be a shared AP at some times and a shared AP at other times.

[0056] like Figure 1As further shown, the shared AP 110 may include processing circuitry 111 and a communication interface 113, specifically a wireless communication interface 113 according to the IEEE 802.11 standard framework. The processing circuitry 111 may be implemented in hardware and / or software and may include digital circuitry, or both analog and digital circuitry. The digital circuitry may include components such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), or general-purpose processors. The shared AP 110 may also include a memory 115 for storing executable program code, which, when executed by the processing circuitry 111, causes the shared AP 110 to perform the functions and methods described herein.

[0057] Similarly, Figure 1 The shared AP 120 shown (as) Figure 1 Examples of other APs shown may include processing circuitry 121 and a communication interface 123, specifically a wireless communication interface 123 according to the IEEE 802.11 standard framework. Processing circuitry 121 may be implemented in hardware and / or software and may include digital circuitry, or both analog and digital circuitry. Digital circuitry may include components such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), or general-purpose processors. The shared AP 120 may also include memory 125 for storing executable program code that, when executed by processing circuitry 121, causes the exemplary shared AP 120 to perform the functions and methods described herein.

[0058] According to the embodiments disclosed herein, multiple APs of Wi-Fi network 100, specifically APs 110, 120, 130, and 140 of M-AP set 125, are configured to operate as shared APs such that inter-set fairness (i.e., fairness between APs of M-AP set 125 and other APs not belonging to M-AP set 125 or coordination protocols within M-AP set 125, such as APs 150, 160, and 170) and / or intra-set fairness (i.e., fairness among APs within M-AP set 125) are observed within Wi-Fi network 100, as will be described in more detail below. The inter-set fairness implemented by the embodiments disclosed herein supports maintaining fairness among all OBSS APs, not just those OBSS APs operating as part of M-AP coordination transport. In other words, according to the embodiments disclosed herein, being part of an M-AP set and / or coordination protocol does not increase the probability of an OBSS AP obtaining channel access compared to any other OBSS AP in Wi-Fi network 100.

[0059] The intra-set fairness implemented in the embodiments disclosed herein is based on the following assumptions: the sharing method of APs participating in M-AP coordinated transmissions may be flexible, and therefore not all APs operating within the M-AP set or under the same coordination protocol within the M-AP set share each TXOP, which is obtained through any member AP in the M-AP set or operating under the same coordination protocol within the M-AP set. Each AP may implement its own algorithm for selecting shared APs, and there is no guarantee that all algorithms provide the same probability of being selected as a shared AP for all APs operating within the M-AP set or under the same coordination protocol within the M-AP set. This unequal probability may cause APs to leave the M-AP set or break already joined coordination protocols, potentially reducing M-AP coordinated transmission gain. Therefore, the intra-set fairness implemented in the embodiments disclosed herein ensures that each AP operating within the M-AP set or under the same coordination protocol within the M-AP set (e.g., M-AP set 125 and / or APs 110, 120, 130, 140 of the coordination protocol) has a similar probability of becoming a shared AP.

[0060] To this end, the embodiments disclosed herein provide new parameters and rules regarding inter-set fairness and / or intra-set fairness for M-AP coordinated transmissions. In the following sections, Figure 2 These embodiments are described in the context of the exemplary shared AP 120 of the M-AP set 125. However, it should be understood, and as mentioned above, that these embodiments are also applicable to other APs 110, 130, 140 in the M-AP set 125.

[0061] In order to communicate with its associated non-AP STA (e.g., non-AP STA 180), AP 120 is used to obtain channel access by participating in coordinated transmission 220a by utilizing at least a portion of at least one transmission opportunity (TXOP) 210a, said at least one TXOP being acquired and shared by an exemplary shared AP 110, which operates under a coordination protocol within and / or within a set of M-APs 125 of a wireless communication network, specifically a Wi-Fi network 100. From the perspective of the shared AP 120, Figure 1 The exemplary Wi-Fi network 100 shown includes one or more first additional APs (i.e., AP 130, 140) that are part of and / or operate under the same coordination protocol within the M-AP set 125, and one or more second additional APs (i.e., AP 150, 160, 170) that operate on the same channel but are not part of the M-AP set 125 or part of the same coordination protocol within the M-AP set 125. As will be described in more detail below, AP 120 (e.g., via its processing circuitry 121) is used to implement one or more fairness timers, including (a) a first fairness timer (also referred to herein as M-APInterSetTimer) for ensuring channel access fairness between AP 120 and one or more second additional APs 150, 160, 170, which operate on the same channel but are not part of M-AP set 125 or the same coordination protocol within M-AP set 125, and / or (b) a second fairness timer (also referred herein as M-APIntraSetTimer) for ensuring channel access fairness between AP 120 and one or more first additional APs 130, 140, which operate under the same coordination protocol within M-AP set 125.

[0062] In one embodiment, AP 120, specifically its processing circuitry 121, is configured to wait for a first fairness timer (i.e., M-APInterSetTimer) to expire, as defined in the IEEE 802.11 standard framework, before resuming contention for channel access by restoring the enhanced distributed channel access (EDCA) backoff counter. In other words, in one embodiment, the first fairness timer defines the period for which AP 120 should maintain the EDCA backoff counter.

[0063] In one embodiment, AP 120, specifically its processing circuitry 121, is configured to wait for a second fairness timer (i.e., M-APIntraSetTimer) to expire before participating in another coordinated transfer within M-AP set 125 or under the same coordination protocol within M-AP set 125. In other words, in one embodiment, the second fairness timer defines the period during which AP 120 cannot operate as a shared AP in another TXOP that includes the coordinated transfer (i.e., cannot assume the role of a shared AP).

[0064] Therefore, based on the embodiments disclosed above, the shared AP 120 that has already obtained channel access using M-AP coordinated transmission can be used to wait for a period of time before the shared AP 120 resumes its backoff counter, i.e., the duration defined by M-APInterSetTimer, and / or before the shared AP 120 can participate in another M-AP coordinated transmission within the M-AP set 125, i.e., the duration defined by M-APIntraSetTimer. In another embodiment, the AP used as the shared AP 120 or used as the shared AP 110 can update the CWmin / CWmax values ​​as defined according to the IEEE 802.11 standard framework to generate a new backoff counter value in order to obtain channel access for the next M-AP coordinated transmission.

[0065] To further illustrate the embodiments described above, Figure 2 The timing diagram for coordinated transmission of APs 110, 120, 130, and 140 is shown, as follows: Figure 1 As shown, APs 110, 120, 130, and 140 define the M-AP set 125 of the Wi-Fi network 100 or the coordination protocol within the M-AP set 125. As described above, APs 110, 120, 130, and 140 of the M-AP set 125 or the coordination protocol within the M-AP set 125 may have already established an M-AP coordination protocol. This M-AP coordination protocol can be defined by an example where the value of the second timer (i.e., M-APIntraSetTimer) is equal to half the value of the first timer (i.e., M-APInterSetTimer). Therefore, in this exemplary embodiment, for a duration of 0.5 * M-APInterSetTimer, any shared AP 120, 130, or 140 that has participated in the M-AP coordination transmission 220a (and obtained channel access) cannot become a shared AP in another TXOP, which is acquired by any member of the M-AP coordination protocol and occurs within the period of the first timer (i.e., M-APInterSetTimer).

[0066] As an example, Figure 2The timing diagram illustrates three transmission opportunities 210a to 210c: the first transmission opportunity TXOP1 210a, the second transmission opportunity TXOP2 210b, and the third transmission opportunity TXOP3 210c. AP 110 is the holder of the first TXOP1 210a, i.e., the sharing AP 110, and AP 110 shares its resources with AP 120 (i.e., the shared AP 120) during the M-AP coordination transmission 220a. According to the embodiment described above, at the end of the first TXOP1 210a, AP 120 must wait for M-APInterSetTimer 250 before AP 120 can continue its backoff count. Furthermore, AP 120 is used to avoid becoming the shared AP for M-APIntraSetTimer 240, i.e., for a period of 0.5 * M-APInterSetTimer (defined by the M-AP coordination protocol established by APs 110 and 120).

[0067] For the second TXOP2 210b, AP 130 is the TXOP holder, i.e., a shared AP, and it shares its resources in its coordinated transmission 220b with AP 110 but not with AP 120 because AP 120's M-APIntraSetTimer 240 has not yet expired. For the third TXOP3 210c, AP 140 is the TXOP holder, i.e., a shared AP, and it shares its resources in the coordinated transmission with AP 120 (whose M-APIntraSetTimer 240 has now expired) and AP 130, but not with AP 110 because AP 110's M-APIntraSetTimer 260 has not yet expired. It should be understood that... Figure 2 The examples shown are for illustrative purposes only, and the time periods shown here may differ in practice during the actual operation of the WLAN network 100 according to the embodiment.

[0068] In one embodiment, the first fairness timer, namely M-APInterSetTimer 250 (or more specifically, its duration), can be defined in units of time (e.g., microseconds, TU). In one embodiment, the second fairness timer, namely M-APIntraSetTimer 240, 260, can also be defined in units of time. Alternatively, the second fairness timer can be defined in integer units of TXOP, for example, M-APIntraSetTimer = 1 * TXOP.

[0069] In one embodiment, the processing circuitry 121 of AP 120 may be used to initialize (i.e., start) the counting of the first fairness timer 250 and / or the second fairness timers 240, 260 at the end of the TXOP, wherein AP 120 participates as a shared AP. In one embodiment, this information may be provided in the duration field of the first PPDU sent by the sharing AP 110 for coordinated transmission during its TXOP.

[0070] In another embodiment, the processing circuitry 121 of AP 120 may be used to initialize (i.e., start) counting first fairness timer 250 and / or second fairness timers 240, 260 at the end of the last PPDU, the last PPDU being sent as a coordinated transmission in which AP 120, triggered by the shared AP 120, has participated as a shared AP 110 (in which case AP 120 may restart the first and / or second fairness timers 240, 250, 260 at the end of each PPDU, each PPDU being sent during an M-AP coordinated transmission triggered by the shared AP 110, in which AP 120 participates as a shared AP).

[0071] In another embodiment, the processing circuitry 121 of AP 120 can be used to initialize (i.e., start) the counting of the first fairness timer 250 and / or the second fairness timers 240, 260 based on dedicated information sent by the shared AP 110. For example, in one embodiment, the shared AP 110 can send a frame including an indication that the first and / or second fairness timers 240, 250, 260 should be started at the end of the current frame. In one embodiment, such a frame provided by the shared AP 110 may include a corresponding indication (e.g., identifier or address) of a specific AP 120, 130, 140 that needs to start its first and / or second fairness timers 240, 250, 260 and / or an indication to trigger all shared APs 120, 130, 140 of the M-AP set 125 or its specific coordination protocol to start their first and / or second fairness timers 240, 250, 260.

[0072] In one embodiment, each shared AP 120, 130, 140 that has participated in the coordinated transmission triggered by shared AP 110 may count its first and / or second M-AP fairness timers 240, 250, 260 according to one or more of the following rules. Shared APs 120, 130, 140 may continuously count the first fairness timer (i.e., M-APInterSetTimer 250) from an initialization point (i.e., the starting point) until the timer reaches zero (as described above, in one embodiment, the first fairness timer (i.e., M-APInterSetTimer 250) is defined in units of time (e.g., microseconds). Where the second fairness timer (i.e., M-APIntraSetTimer 240, 260) is also defined in units of time, shared APs 120, 130, 140 may continuously count the second fairness timer (i.e., M-APIntraSetTimer 240, 260) from an initialization point (i.e., the starting point) until the timer reaches zero. In the alternative case where the second fairness timer (i.e., M-APIntraSetTimer 240, 260) is defined in integer units of TXOP, the shared APs 120, 130, 140 can be used to decrement the second fairness timer (i.e., M-APIntraSetTimer 240, 260) whenever TXOP is owned by an AP from the same M-AP set 125 or an AP operating under the same coordination protocol within the M-AP set 125.

[0073] In certain scenarios, such as for specific TXOPs, the restrictions on being shared APs can be relaxed. For example, if all APs 110, 120, 130, and 140 within M-AP set 125 and / or its coordination protocol are shared in a particular TXOP, there is no reason to prevent any of them from being shared in the next TXOP acquired by any AP 110, 120, 130, or 140 that is a member of M-AP set 125 and / or its coordination protocol (because there is no fairness issue among shared APs within a specific M-AP coordination protocol).

[0074] Therefore, in one embodiment, to support operation in a dynamic environment, an indication can be added to the shared AP at the beginning of the TXOP to indicate (a) whether restrictions on participation in coordinated transmissions (such as those set as part of the coordination protocol) should be applied after the current TXOP has ended, i.e., for using a second fairness timer (i.e., M-APIntraSetTimer 240, 260 as defined in the coordination protocol), or (b) whether the second fairness timer (i.e., M-APIntraSetTimer 240, 260) should be set to zero for the current TXOP after it has ended. In one embodiment, the indication may include a single indication, i.e., a flag bit. In one embodiment, the indication (e.g., the flag bit) may be added by the shared AP 110 to an M-AP notification frame (sent by the shared AP at the beginning of the TXOP it acquires).

[0075] As mentioned above Figure 2 In the context described above, in one embodiment, the first fairness timer (i.e., M-APInterSetTimer 250) and the second fairness timer (i.e., M-APIntraSetTimer 240, 260) can be associated, for example, through the following relationships: M-APInterSetTimer = 0.5 * M-APInterSetTimer. Based on this correlation, the APs in the M-AP set of 125 can use the M-APFairnessFactor, which will be described in more detail below.

[0076] As described above, in one embodiment, the first fairness timer (i.e., M-APInterSetTimer 250) defines the period during which the corresponding shared AP maintains (i.e., freezes) its EDCA backoff counter. In one embodiment, M-APFairnessFactor can be defined as the ratio between M-APIntraSetTimer and M-APInterSetTimer, i.e., M-APFairnessFactor = M-APIntraSetTimer / M-APInterSetTimer. In one embodiment, M-APIntraSetTimer = M-APFairnessFactor * M-APInterSetTimer can be considered as a portion of the M-APInterSetTimer period during which the corresponding shared AP cannot participate in future coordinated transmissions (e.g., {0, ¼, ½, 1} for different M-APFairnessFactors). A zero value for M-APFairnessFactor indicates no restriction on participation in coordinated transmissions.

[0077] As described above, in another embodiment, the second fairness timer (i.e., M-APIntraSetTimer 240, 260) defines the period during which the corresponding AP cannot participate in future coordinated transmissions as a shared AP. In one embodiment, M-APInterSetTimer = M-APFairnessFactor * M-APIntraSetTimer can be considered as a multiple of the M-APIntraSetTimer period, during which the corresponding AP should maintain (i.e., preserve) a backoff counter (e.g., {1, 2, 4, 8} for different M-APFairnessFactors).

[0078] In one embodiment, one or more parameters related to the embodiments described above may be indicated within the M-AP EDCA information element. More specifically, in one embodiment, the M-AP EDCA information element may include at least: a first fairness timer, namely M-APInterSetTimer; a second fairness timer, namely M-APIntraSetTimer; a fairness factor (if the two timers are related); a minimum size of the M-AP contention window; a maximum size of the M-AP contention window; an M-AP arbitration interframe space number (AIFSN); and / or a fairness timer initialization point.

[0079] In one embodiment, during the protocol establishment process regarding parameters of the first and / or second fairness timer, M-AP EDCA information elements may be included in coordination protocol frames exchanged between APs. In one embodiment, the parameters may be valid throughout the coordination protocol period.

[0080] According to another embodiment, M-AP EDCA information elements may be included in the M-AP notification frame. In other words, at the beginning of the TXOP, the shared AP may include parameters in the M-AP notification frame to ensure that each shared AP participating in the M-AP coordination transmission uses the same parameters. In one embodiment, the parameters may be valid for the current TXOP. It should be understood that this embodiment also includes cases where a coordination protocol is not present.

[0081] In one embodiment, when operating as a shared AP, each AP 120, 130, 140 may be used to operate according to one or more of the following rules: (i) each shared AP 120, 130, 140 that has been sent as part of a coordination transport triggered by the shared AP 110 sets its internal timer to the value of the first fairness timer (i.e., M-APInterSetTimer) according to the M-AP fairness timer initialization option described above; (ii) the EDCA backoff counter of the corresponding shared AP 120, 130, 140 may only be restored when the value of the first fairness timer (i.e., M-APInterSetTimer) reaches zero; (iii) an AP that is a member of the M-AP set 125 and / or its coordination protocol should not approve any participation within the coordination transport as a shared AP if its M-APIntraSetTimer > 0; (iv) once the shared AP If 110 completes the M-AP coordination transmission for the acquired TXOP, it can be used to generate a new backoff value using parameters M-APCWmin and M-APCWmax; and / or (v) if triggered, the corresponding AP can respond to the management poll sent by the shared AP 110 for the entire first fairness timer (i.e., the M-APInterSetTimer period).

[0082] In one embodiment, each AP 110, 120, 130, 140 within the M-AP set 125 and / or its coordination protocol is responsible for maintaining its own M-AP EDCA parameters. Therefore, to support the shared AP in determining which AP can potentially become the shared AP, it can send a polling frame 310, such as... Figure 3 As shown, this is to obtain short responses from all other APs operating under the same coordination protocol within the M-AP set 125. In one embodiment, an AP can reply with a true / false answer (i.e., true if the second fairness timer (i.e., the M-APIntraSetTimer 250 counter) has reached zero).

[0083] In one embodiment, the M-AP timer status polling frame 310 may be part of an M-AP notification frame or sent as a separate frame by the sharing AP 110. The sharing AP 110 may be used to request participation in the coordination transmission only from APs within the M-AP set 125 and / or its coordination protocol, which responded "yes" or "true" to the previous M-AP timer status polling frame 310 in the M-AP timer status response frame 320. In one embodiment, the M-AP timer status polling frame 310 sent by the sharing AP 110 may include one or more of the following information elements: M-AP set ID; coordination protocol ID; and / or a list of AP IDs.

[0084] Figure 4 This is a flowchart illustrating a method 400 for operating an AP (e.g., AP 120) to obtain channel access by participating in a coordinated transmission 220a using at least a portion of at least one transmission opportunity (TXOP) 210a, the at least one TXOP being acquired and shared by a shared AP 110 operating under a coordination protocol of a wireless communication network 100 and / or within an M-AP 125. Method 400 includes step 401: implementing one or more fairness timers, the one or more fairness timers including: a first fairness timer 250 for ensuring channel access fairness between AP 120 and one or more second additional APs 150, 160, 170, the one or more second additional APs 150, 160, 170 operating on the same channel but not part of M-AP set 125 or a coordination protocol within M-AP set 125; and / or second fairness timers 240, 260 for ensuring channel access fairness between AP 120 and one or more first additional APs 130, 140 operating under the same coordination protocol within M-AP set 125.

[0085] Since method 400 can be implemented, for example, by AP 120, when running as the shared AP 120, other features of method 400 come directly from the functionality of the shared AP 120 and its various embodiments described above and below.

[0086] Figure 5This is a flowchart illustrating a method 500 for operating an AP 110 as a shared AP 110, the AP 110 being used to manage channel access of one or more first additional APs 120, 130, 140 by participating in a coordinated transmission 220a using at least a portion of at least one transmission opportunity (TXOP) 210a, the at least one TXOP being acquired and shared by the AP 110, the AP 110 operating as a shared AP 110, operating under a coordination protocol of the wireless communication network 100 and / or within the M-AP set 125. As described above, each of one or more first additional APs 120, 130, 140 is used to implement one or more fairness timers, the one or more fairness timers including: a first fairness timer 250 for ensuring channel access fairness between APs 120, 130, 140 and one or more second additional APs 150, 160, 170, the one or more second additional APs 150, 160, 170 operating on the same channel but not part of the M-AP set 125 or a coordination protocol within the M-AP set 125; and / or second fairness timers 240, 260 for ensuring channel access fairness between APs 120, 130, 140 and other first additional APs 120, 130, 140 operating under the same coordination protocol within the M-AP set 125. Method 500 includes step 501: sending an M-AP timer status polling frame 310 (e.g., ...) to one or more first additional APs 120, 130, 140. Figure 3 (as shown) and / or an M-AP notification frame aggregated with the M-AP timer status polling frame 310 to request information 320 about the second fairness timers 240, 260.

[0087] Since method 500 can be implemented by AP 110 operating as a shared AP 110, other features of method 500 are derived directly from the functionality of the AP operating as a shared AP 110 and its various embodiments described above and below.

[0088] In the following sections, simulation results obtained for multiple APs implementing the first fairness timer 250 and / or the second fairness timers 240, 260 will be presented. Figure 6 , Figure 7 and Figure 8 Described in the context of [the above]. These simulations have been performed for an exemplary Wi-Fi network 100 with 10 OBSSAPs, where 4 of these OBSSAPs ( Figure 6The AP indices 1 to 4 in the M-AP set 125 and / or the M-AP coordination protocol within the M-AP set 125 are established, and comparisons are made between AP1 to AP4 when they are used as shared APs, using the regular EDCA rules for all OBSS APs and the first fairness timer (i.e., M-APInterSetTimer 250) when applied. For the remaining OBSS APs, the regular EDCA rules are applied. Figure 6 and Figure 7 It can be seen that applying the first fairness timer (i.e., using M-APInterSetTimer 250) to APs 1 to 4 (i.e. within the M-AP set 125) results in fewer conflicts and also reduces the "unfairness gap" between APs within the M-AP set 125 and the remaining OBSS APs.

[0089] Regarding fairness within the set, a similar simulation has been performed, assuming an identical Wi-Fi network 100 with 10 OBSS APs, of which 4 of these OBSS APs ( Figure 8 AP indices 1 to 4) establish the M-AP set 125 and / or the M-AP coordination protocol within the M-AP set 125. For this simulation, the APs within the M-AP set 125 implement the M-AP rules described above, i.e., the M-APInterSetTimer has a non-zero value, while the remaining OBSS APs operate according to the regular EDCA rules. Furthermore, two algorithms have been used for selecting the shared APs: one with equal probability and one with higher probability for the AP with the lower index to be selected (i.e., AP1). Both selection algorithms were initially run without applying a second fairness timer (i.e., M-APIntraSetTimer), resulting in a very unequal channel access ratio. In fact, AP1 received more channel access opportunities than other APs in the M-AP set, which can be seen from... Figure 8 The results are obtained from the corresponding left bar representing the algorithm. When the second fairness timer (i.e., M-APIntraSetTimer 240, 260) is applied (for this simulation, it is assumed that the duration of the second fairness timer is equal to 1 / 4 of the CWMin duration), the differences between APs within the M-AP set 125 decrease (i.e., they have been balanced), resulting in a channel access ratio similar to that of algorithms with equal probabilities (such as...). Figure 8 (As shown in the corresponding middle and right bars).

[0090] Those skilled in the art will understand that “blocks” (“units”) in the various drawings (methods and apparatuses) represent or describe the functionality of embodiments of the invention (and are not necessarily independent “units” in hardware or software), thereby equally describing the functionality or features (unit = step) of apparatus embodiments and method embodiments.

[0091] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the described apparatus embodiments are merely exemplary. For example, the unit division is merely a logical functional division, and in actual implementation, it can be another division. For example, multiple units or components can be merged or integrated into another system, or some features can be ignored or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be implemented through some interface. Indirect coupling or communication connection between devices or units can be implemented electronically, mechanically, or otherwise.

[0092] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiment solution according to actual needs.

[0093] In addition, the functional units in the embodiments disclosed herein may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

Claims

1. An access point (AP) (120), characterized in that, For obtaining channel access by participating in coordinated transmission using at least a portion of at least one transmission opportunity (TXOP) (210a to 210c), said at least one TXOP (210a to 210c) being acquired and shared by an AP (110) operating as a shared AP (110), said AP (110) operating under a coordination protocol of a wireless communication network (100) and / or within a multi-AP (M-AP) set (125), said wireless communication network (100) also including one or more first additional APs (130, 140) operating as part of said M-AP (125) set and / or under the same coordination protocol, wherein said AP (120) is used to implement one or more fairness timers, The one or more fairness timers include: a first fairness timer for ensuring channel access fairness between the AP (120) and one or more second additional APs (150, 160, 170), which operate on the same channel but are not part of the M-AP set (125) or the same coordination protocol or another coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the AP (120) and the first additional AP (130, 140), which operate under the same coordination protocol and / or are part of the M-AP set (125).

2. The AP (120) according to claim 1, characterized in that, The AP (120) is configured to implement the first fairness timer after being shared by the AP (110) operating as the shared AP (110) for coordinating transmissions, the AP (110) having acquired the TXOP (210a to 210c) to ensure the channel access fairness between the AP (120) and the one or more second additional APs (150, 160, 170) operating on the same channel but not part of the M-AP set (125) or the same coordination protocol or another coordination protocol, and the AP (120) is configured to wait for the first fairness timer to end its count before resuming competition for the acquisition of the channel access.

3. The AP (120) according to claim 2, characterized in that, The AP (120) is used to wait for the first fairness timer to end before resuming contention for channel access by resuming the enhanced distributed channel access (EDCA) backoff counter.

4. The AP (120) according to claim 2 or 3, characterized in that, The fairness first timer is defined in units of time.

5. The AP (120) according to any one of the preceding claims, characterized in that, The AP (120) is used to implement the second fairness timer to ensure channel access fairness between the AP (120) and the first additional AP (130, 140), which is shared by the AP (110) operating as the shared AP (110), operates under the same coordination protocol within the M-AP set (125), and the AP (120) is used to wait for the second fairness timer to end before participating in another coordinated transmission within the M-AP set (125) or under the same coordination protocol within the M-AP set (125).

6. The AP (120) according to claim 5, characterized in that, The second fairness timer is defined in units of time.

7. The AP (120) according to claim 5 or 6, characterized in that, The second fairness timer is defined in units of TXOP (210a to 210c).

8. The AP (120) according to claim 7, characterized in that, The AP (120) is used to count down the second fairness timer, defined in units of TXOPs (210a to 210c), by decrementing the second fairness timer whenever the TXOPs (210a to 210c) are held by one or more of the first additional APs (130, 140), which operate in the M-AP set (125) or under the same coordination protocol within the M-AP set (125).

9. The AP (120) according to claim 8, characterized in that, The AP (120) is used to start the first fairness timer and / or the second fairness timer at the end of the TXOP (210a to 210c).

10. The AP (120) according to claim 9, characterized in that, The AP (120) is used to receive a PPDU from the AP (110) operating as the shared AP (110), wherein the PPDU includes an indication of the duration of the TXOP (210a to 210c) that initiates the first fairness timer and / or the second fairness timer.

11. The AP (120) according to any one of claims 1 to 8, characterized in that, The AP (120) is used to be triggered by the AP (110) operating as the shared AP (110) to send at least one PPDU as a coordinated transmission, wherein the AP (120) is used to start the first fairness timer and / or the second fairness timer when the at least one PPDU ends.

12. The AP (120) according to claim 11, characterized in that, The AP (120) is configured to restart the first fairness timer and / or the second fairness timer if the AP (120) is triggered by the AP (110) operating as the shared AP (110) to send at least one additional PPDU as a coordinated transmission.

13. The AP (120) according to any one of claims 1 to 8, characterized in that, The AP (120) is used to receive a frame from the AP (110) operating as the shared AP (110), wherein the frame instructs the AP (120) to start the first fairness timer and / or the second fairness timer at the end of the frame.

14. The AP (120) according to claim 13, characterized in that, The frame includes one or more identifiers that indicate one or more of the APs (120) and / or the first additional APs (130, 140) operating under the same coordination protocol in the M-AP set (125) to start the first fairness timer and / or the second fairness timer at the end of the frame.

15. The AP (120) according to any one of the preceding claims, characterized in that, The first fairness timer and / or the second fairness timer are defined by the coordination protocol upon which the AP (120) operates.

16. The AP (120) according to any one of the preceding claims, characterized in that, Before or at the start of the TXOP (210a to 210c), the AP (120) is configured to receive a frame from the AP (110) operating as the shared AP (110), wherein the frame includes an indication for indicating whether the AP (120) counts the second fairness timer before participating in another coordinated transmission initiated by any AP (110, 130, 140) operating in the same M-AP set (125) as the AP (120).

17. The AP (120) according to any one of the preceding claims, characterized in that, The ratio between the values ​​of the first fairness timer and the second fairness timer, or the ratio between the values ​​of the second fairness timer and the first fairness timer, is defined by a fairness factor.

18. The AP (120) according to claim 17, characterized in that, The fairness factor has a value of 1 or greater, or the fairness factor is in the range of 0 to 1, including the boundary values ​​0 and 1.

19. The AP (120) according to claim 17 or 18, characterized in that, The AP (120) is used to receive frames containing M-AP EDCA information elements from the AP (110) operating as the shared AP (110) within the M-AP set (125), wherein the M-AP EDCA information elements include one or more parameters, the one or more parameters including: a first fairness timer; a second fairness timer; the fairness factor; the minimum size of the M-AP contention window; the maximum size of the M-AP contention window; the M-AP arbitration interframe space number (AIFSN); and / or the fairness timer initialization point.

20. The AP (120) according to claim 19, characterized in that, The AP (120) is used to derive the M-APEDCA information element as a component of the frame containing the coordination protocol and is sent from the AP (110) operating as the shared AP (110), wherein one or more parameters of the M-AP EDCA information element are valid for the duration of the coordination protocol.

21. The AP (120) according to claim 19, characterized in that, The AP (120) is used to derive the M-APEDCA information element as a component of the M-AP notification frame, which is sent by the AP (110) operating as the shared AP (110), wherein one or more parameters of the M-AP EDCA information element are valid for the current TXOP (210a to 210c).

22. The AP (120) according to any one of the preceding claims, characterized in that, The AP (120) is used to send information to the AP (110) operating as the shared AP (110) indicating whether the second fairness timer has expired, the AP (110) operating under the same coordination protocol within the M-AP set (125).

23. The AP (120) according to claim 22, characterized in that, The AP (120) is configured to send an M-AP timer status response frame (320) to the AP (110) operating as the shared AP (110) in response to receiving an M-AP timer status polling frame (310) and / or an M-AP notification frame aggregated with the M-AP timer status polling frame, the AP (110) operating as the shared AP (110) operating under the same coordination protocol within the M-AP set (125), the M-AP timer status response frame (320) including information indicating whether the second fairness timer has expired.

24. The AP (120) according to claim 23, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include an M-AP set identifier indicating the M-AP set (125).

25. The AP (120) according to claim 23 or 24, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include a coordination protocol identifier, wherein the coordination protocol identifier identifies one of a plurality of coordination protocols within the M-AP set (125), and the AP (110) operates as the shared AP (110), and the AP (120) operates under the coordination protocol identified by the coordination protocol identifier within the M-AP set (125).

26. The AP (120) according to any one of claims 23 to 25, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include an identifier of the AP (120) and / or one or more identifiers of the one or more first additional APs (130, 140) operating under the same coordination protocol in or within the M-AP set (125), the identifiers indicating that the AP (120, 130, 140) is requested to send an M-AP timer status response frame (320) to the AP (110) operating as the shared AP (110).

27. The AP (120) according to any one of claims 23 to 26, characterized in that, The AP (120) is used to send the M-AP timer status response frame (320) to the AP (110) operating as the shared AP (110), which operates the same coordination protocol within the M-AP set (125), regardless of whether the first fairness timer and / or the second fairness timer have ended.

28. A method (400) for operating an access point (AP) (120), characterized in that, The AP 120 is used to obtain channel access by participating in coordinated transmission using at least a portion of at least one transmission opportunity (TXOP) (210a to 210c), the at least one TXOP (210a to 210c) being acquired and shared by an AP (110) operating as a shared AP (110), the AP (110) operating under a coordination protocol of a wireless communication network (100) and / or within a multi-AP (M-AP) set (125), the wireless communication network (100) also including one or more first additional APs (130, 140) operating as part of the M-AP set (125) and / or under the coordination protocol, wherein the method (400) includes implementing (401) one or more fairness timers. The one or more fairness timers include: a first fairness timer for ensuring channel access fairness between the AP (120) and one or more second additional APs (150, 160, 170), which operate on the same channel but are not part of the M-AP set (125) or the coordination protocol or another coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the AP (120) and the one or more first additional APs (130, 140), which operate under the same coordination protocol within the M-AP set (125).

29. An AP (110), characterized in that, Operating as a shared AP (110), for managing channel access of one or more first additional APs (120, 130, 140) by utilizing at least a portion of at least one transmission opportunity (TXOP) (210a to 210c) acquired and shared by the AP (110) operating as the shared AP (110) to participate in coordinated transmission, the AP (110) operating under a coordination protocol of a wireless communication network (100) and / or within a multi-AP (M-AP) set (125), wherein each of the one or more first additional APs (120, 130, 140) is configured to implement one or more fairness timers, the one or more fairness timers comprising: a first fairness timer for ensuring that the first additional APs (120, 130, 140) cooperate with one or more second additional APs (150, 160, 170, 180, 19 ... Channel access fairness between the first additional APs (120, 130, 140) and other first additional APs (120, 130, 140) operating on the same channel but not part of the M-AP set (125) or the coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the first additional APs (120, 130, 140) and other first additional APs (120, 130, 140) operating under the same coordination protocol within the M-AP set (125), wherein the AP (110) operating as the shared AP (110) is used to send an M-AP timer status polling frame (310) and / or an M-AP notification frame aggregated with the M-AP timer status polling frame (310) to the one or more first additional APs (120, 130, 140) to request information about the second fairness timer.

30. The AP (110) according to claim 29, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include an M-AP set identifier indicating the M-AP set (125).

31. The AP (110) according to claim 29 or 30, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include a coordination protocol identifier, wherein the coordination protocol identifier identifies one of a plurality of coordination protocols within the M-AP set (125), and the AP (110) operates as the shared AP (110), and the one or more first additional APs (120, 130, 140) operate under the coordination protocol identified by the coordination protocol identifier within the M-AP set (125).

32. The AP (110) according to any one of claims 29 to 31, characterized in that, The M-AP timer status polling frame (310) and / or the M-AP notification frame include one or more identifiers of the one or more first additional APs (120, 130, 140) operating under the same coordination protocol in the M-AP set (125), the one or more identifiers indicating that the first additional AP (120, 130, 140) is requested to send an M-AP timer status response frame (320) to the AP (110) operating as the shared AP (110).

33. The AP (110) according to any one of claims 29 to 32, characterized in that, The AP (110) operating as the shared AP (110) is used to receive an M-AP timer status response frame (320) from one or more first additional APs (120, 130, 140), wherein the M-AP timer status response frame (320) includes information about the second fairness timer.

34. The AP (110) according to any one of claims 29 to 33, characterized in that, The AP (110) operating as the shared AP (110) is used to send an instruction to the one or more first additional APs (120, 130, 140) for setting the second fairness timer of each of the one or more first additional APs (120, 130, 140) to zero for the current TXOP (210a to 210c).

35. The AP (110) according to claim 34, characterized in that, The AP (110) operating as the shared AP (110) is used to send an M-AP notification frame to the one or more first additional APs (120, 130, 140), wherein the M-AP notification frame includes the indication for setting the second fairness timer of each of the one or more first additional APs (120, 130, 140) to zero for the current TXOP (210a to 210c).

36. The AP (110) according to any one of claims 29 to 35, characterized in that, The AP (110) operating as the shared AP (110) is used to send frames containing M-AP EDCA information elements to one or more first additional APs (120, 130, 140) within the M-AP set (125), wherein the M-AP EDCA information elements include one or more parameters, the one or more parameters including: a first fairness timer; a second fairness timer; a fairness factor defined by the ratio between the first fairness timer and the second fairness timer; a minimum size of the M-AP contention window; a maximum size of the M-AP contention window; an M-AP arbitration interframe space number (AIFSN); and / or a fairness timer initialization point.

37. The AP (110) according to claim 36, characterized in that, The AP (110) operating as the shared AP (110) is configured to generate a new backoff counter value based on the minimum and maximum size of the M-AP contention window once the AP (110) operating as the shared AP (110) has completed the M-AP coordinated transmission of at least one TXOP.

38. A method (500) for operating AP (110), characterized in that, The AP (110) operates as a shared AP (110) and is used to manage channel access of one or more first additional APs (120, 130, 140) by coordinating transmissions using at least a portion of at least one transmission opportunity (TXOP) acquired and shared by the AP (110) operating as the shared AP (110), the AP (110) operating under a coordination protocol of the wireless communication network (100) and / or within a multi-AP (M-AP) set (125), wherein each of the one or more first additional APs (120, 130, 140) is used to implement one or more fairness timers, the one or more fairness timers including: a first fairness timer for ensuring channel access fairness between the AP (120, 130, 140) and one or more second additional APs (150, 160, 170), the one or more second additional APs (150, 160, 170, 180, 19 ... 170) Operating on the same channel but not part of the M-AP set (125) or the coordination protocol; and / or a second fairness timer for ensuring channel access fairness between the APs (120, 130, 140) and other first additional APs (120, 130, 140) operating under the same coordination protocol within the M-AP set (125), wherein the method (500) includes sending (501) an M-AP timer status polling frame (310) and / or an M-AP notification frame aggregated with the M-AP timer status polling frame (310) to the one or more first additional APs (120, 130, 140) to request information about the second fairness timer.

39. A computer program product, characterized in that, Includes a computer-readable storage medium for storing program code, which, when executed by a computer or processor, causes the computer or processor to perform the method (400) according to claim 28 or the method (500) according to claim 38.

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