Communication apparatus and communication method for coordinating service periods

Abstract

Communication devices and methods for coordinating service periods (SPs) are provided. A first aspect provides a first access point (AP) including: circuitry for generating a request frame indicating a request to set up one or more coordinated SPs; and a transmitter for sending the request frame to a second AP. A second aspect provides a non-AP STA including: a receiver for receiving a beacon frame or action frame from its associated AP; circuitry for extracting information about coordinated SPs from the frame; and a transmitter for sending a request frame to the AP indicating a request to join an SP.

Description

Technical Field

[0001] This embodiment generally relates to communication devices, and more specifically, to methods and apparatus for coordinating service periods (SPs). Background Technology

[0002] In the standardization of next-generation wireless local area networks (WLANs), new radio access technologies with backward compatibility with IEEE 802.11a / b / g / n / ac / ax technologies have been discussed in the IEEE 802.11be task group.

[0003] In 11ax High Efficiency (HE) WLANs, multi-frame transmission during transmission opportunity (TXOP) is supported, enabling stations (STAs) to send additional frames in the transmission queue. In 11be Extremely High Throughput (EHT) WLANs, to improve throughput, especially for cell-edge STAs, coordinated transmission in multi-AP systems has been proposed, including coordinated orthogonal frequency-division multiple access (C-OFDMA), coordinated time-division multiple access (C-TDMA), coordinated beamforming (C-BF), coordinated spatial reuse (C-SR), and coordinated multi-user multiple input multiple output (C-MU-MIMO).

[0004] Various multi-AP coordination schemes are being considered in IEEE 802.11be. For time-domain coordination scheduling, access providers (APs) coordinate their transmission timing. In spatial reuse (SR) coordination, APs coordinate their transmission power. In C-OFDMA, APs coordinate resource unit (RU) assignments. In beamforming (BF) coordination, access points coordinate BF. In multi-user multiple-input multiple-output (MU-MIMO) coordination (also known as joint transmission), APs coordinate their MU-MIMO transmissions.

[0005] However, there has been no discussion about coordinated service hours (SP) so far.

[0006] Therefore, there is a need for communication devices and methods capable of solving the aforementioned problems. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and the background of this disclosure. Summary of the Invention

[0007] Non-limiting and exemplary embodiments help to provide communication devices and communication methods for coordinating SPs.

[0008] According to one aspect of this disclosure, a first access point (AP) is provided, comprising: circuitry for generating a request frame indicating a request to set one or more coordinated service periods (SPs); and a transmitter for sending the request frame to a second AP.

[0009] According to another aspect of this disclosure, a non-AP STA is provided, comprising: a receiver that receives one of a beacon frame or an action frame from its associated AP; circuitry that extracts information of an SP for coordinating transmission from the frame; and a transmitter that sends a request frame to the AP, the request frame indicating a request to join the SP.

[0010] According to another aspect of this disclosure, a method is provided, comprising: generating a request frame indicating a request to set up one or more coordinating SPs; and sending the request frame to an AP.

[0011] It should be noted that general or specific embodiments may be implemented as systems, methods, integrated circuits, computer programs, storage media, or any alternative combination thereof. Further benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. These benefits and / or advantages can be obtained individually from the various embodiments and features in the specification and drawings, and it is not necessary to provide all embodiments and features to obtain one or more such benefits and / or advantages. Attached Figure Description

[0012] The accompanying drawings are used to illustrate various embodiments and explain the various principles and advantages of the embodiments. In the drawings, the same reference numerals refer to the same or functionally similar elements in separate views. The drawings, together with the following detailed description, are incorporated into and form a part of the specification.

[0013] Figure 1 The diagram illustrates a flowchart, based on an example, of communication using enhanced service periods for priority-ordering services.

[0014] Figure 2 An example of a coordination service period for multi-AP coordinated transmission is shown.

[0015] Figure 3 and Figure 4 An example of an overlapping wireless network is shown, each wireless network may include at least one access point (AP) and at least one communication device.

[0016] Figure 5 An EHT action frame based on an example is shown.

[0017] Figure 6 The image shows an example AP coordination session action frame.

[0018] Figure 7 A coordinated transmission sequence based on an example is described.

[0019] Figure 8 A coordinated transmission sequence based on another example is described.

[0020] Figure 9 An example of coordinating SP transmission is shown.

[0021] Figure 10 An example of a TWT setup frame for setting up a TWT request / response for a coordinating SP is shown.

[0022] Figure 11 Another example of coordinating SP transmission is shown.

[0023] Figure 12An example of an Ethernet 89-0d data frame used for multi-AP buffer status reporting is shown.

[0024] Figure 13 An example of an EHT capability element is shown.

[0025] Figure 14 Another example of an 802.11 data frame used to set up a coordination SP is shown.

[0026] Figure 15 Another example of coordinating SP transmission is shown.

[0027] Figure 16 An example of a coordinated SP request action frame is shown.

[0028] Figure 17 A sample table of coordinated SP type values ​​is shown.

[0029] Figure 18 An example of a coordinated SP response action frame is shown.

[0030] Figure 19 An example of a TWT setup frame for setting up a multi-AP coordinated TWT SP is shown.

[0031] Figure 20 An example of a TWT element for setting up a multi-AP coordination TWT SP for C-TDMA is shown.

[0032] Figure 21 An example diagram of a coordinated SP for C-TDMA is shown.

[0033] Figure 22 An example diagram of a coordinated SP for C-TDMA + C-OFDMA is shown.

[0034] Figure 23 An example of coordinated SP transmission using enhanced TWT SP is shown.

[0035] Figure 24 Another example of coordinated SP transport using enhanced TWT SP is shown.

[0036] Figure 25 An example of a data frame using the “Ethernet 89-0d” frame body is shown, which is used to request information about the service hours of an AP or to share the service hours of an AP with other APs.

[0037] Figure 26 Another example table of coordinated SP type values ​​is shown.

[0038] Figure 27An example of a TWT SP information request / response action frame is shown, which is used to request information about the service hours of an AP or to share information about the service hours of an AP with other APs.

[0039] Figure 28 An example of C-TDMA transmission using broadcast-enhanced TWT SP is shown.

[0040] Figure 29 The TWT setup frame is shown, which can be used to add an existing TWT SP to another AP via a separate TWT setup.

[0041] Figure 30 The TWT setup frame is shown, which can be used to enable an AP to join a scheduled broadcast SP that other APs are interested in.

[0042] Figure 31 An example diagram is shown illustrating the use of sub-SPs to protect sensitive business operations.

[0043] Figure 32 Configurations of communication devices according to various embodiments are shown, such as communication apparatuses, for example, sharing APs or shared APs.

[0044] Figure 33 Configurations of communication devices according to various embodiments are shown, such as communication apparatuses, for example, non-AP STAs.

[0045] Figure 34 A flowchart illustrating a method for coordinating SPs according to various embodiments is shown.

[0046] Figure 35 A schematic partial cross-sectional view is shown, which can be implemented for coordinating SPs according to various embodiments.

[0047] Those skilled in the art will understand that the elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. Detailed Implementation

[0048] The following detailed descriptions are merely exemplary in nature and are not intended to limit the embodiments or their application and use. Furthermore, they are not intended to be limited to any theory presented in the foregoing background or detailed descriptions. Moreover, other desirable features and characteristics will become apparent from the following detailed descriptions and appended claims, taken in conjunction with the accompanying drawings and the background information disclosed herein.

[0049] Multi-AP coordination based on shared transmission opportunity (TXOP) has been accepted in 802.11be, where APs perform coordinated transmissions within a shared TXOP. Examples include C-OFDMA / C-TTIME DMA and C-SR based on shared TXOP.

[0050] Singapore Patent Application No. 10202012139Q discusses a mechanism to protect priority services (e.g., low latency or National Security and Emergency Preparedness (NSEP) services) within the enhanced target wait time (TWT) by restricting channel access (from non-designated services) within the basic service set (BSS).

[0051] For example, Figure 1A flowchart 100 illustrating communication using enhanced service periods for priority-ordered services is shown, based on an example diagram. Contention-based channel access procedures (e.g., enhanced distributed channel access (EDCA) procedures) are illustrated by blocks 108, 110, 114, 118, 122, 124, 132, and 134. For simplicity, acknowledgment frames (e.g., ACK, BlockAck frames) are not explicitly shown, but they are understood to be present where needed. AP 102 may send beacon frames 109 to announce the existence of enhanced TWT SPs 121, 129, where only low-latency services are permitted. Any STA (such as STA1 104) that needs to access the channel during enhanced TWT SPs 121, 129 can then negotiate membership in enhanced TWT SPs 121, 129 with AP 102 via TWT request / response frame exchange. Specifically, during TWT negotiation phase 112, STA1 104 sends a TWT request frame to AP 102 to request membership in Enhanced TWT SPs 121 and 129, and AP 102 then sends a TWT response frame to STA1 104 to grant membership. In TWT negotiation phase 117, STA1 104 can request, suggest, or demand the TWT parameter set for Enhanced TWT SPs 121 and 129, and AP 102 can accept or reject, or propose alternative settings. The first target beacon transmission time (TBTT) 116 can also be negotiated during negotiation phase 112. This now allows STA1 to access the channel and exchange low-latency services during Enhanced TWT SPs 121 and 129. The broadcast TWT ID field of the TWT element included in the TWT request frame or TWT response frame is set to a non-zero value (e.g., 1) to indicate a broadcast TWT.

[0052] STA1 can enter a dozing state and wake up after the first TBTT 116 to receive beacon frame 119 from AP 102. Beacon frame 119 may include a broadcast TWT element, which includes further TWT information such as the broadcast TWT (e.g., broadcast TWT1 120), the TWT wake-up interval 130, and the minimum TWT wake-up duration (as indicated by the dashed boxes of enhanced TWT SPs 121, 129). The TWT element also indicates that this is an enhanced TWT and that only low-latency traffic is permitted during this TWT SP.

[0053] STA1 can go to sleep after receiving beacon frame 119 and wake up to broadcast TWT1 SP 121. Since STA1 is a member of the TWT TP and has low-latency (LL) services to transmit, it does not set its network allocation vector (NAV) when waking up for the enhanced TWT SP. During this first enhanced TWT SP 121, AP 102 and STA1 104 exchange low-latency services, such as low-latency downlink (LL DL) signal 123 and low-latency uplink (LL UL) signal 125, respectively.

[0054] STA1 104 can enter sleep mode after the first enhanced TWT SP 121 ends. STA1 104 can wake up for the next broadcast TWT1 SP 129 according to the TWT wake-up interval 130 specified in the negotiation phase or beacon frame 119. During this second enhanced TWT SP 129, AP 102 and STA1 104 transmit LL DL PPDU 133 and LL ULPPDU 135, respectively.

[0055] On the other hand, any third-party STA (such as STA2 106) that has not yet negotiated membership with AP 102 and is therefore not a member of the Enhanced TWT SP is not allowed to access the channel during Enhanced TWT SPs 121 and 129, as indicated by dashed boxes 126 and 136. This can be achieved by STA2 checking whether it is a member of the Enhanced TWT SP when it wakes up for Enhanced TWT SPs 121 and 129; and since it is not, setting its NAV for the duration of the TWT SP. The Enhanced TWT SP can also be called a Restricted TWT SP because during the TWT SP, transmission of traffic types with TIDs other than the Traffic ID (TID) allowed by the TWT SP is restricted. To further restrict transmissions by conventional STAs during Enhanced TWT SPs, the AP can further send silent elements / silent channel elements to schedule silent intervals overlapping with the Enhanced TWT SP. For non-AP legacy STAs, control of the channel is lost at the beginning of the silence interval, and the NAV is set by all non-AP legacy STAs in the BSS for the length of the silence interval established by the silence element / silent channel element, thereby restricting non-AP legacy STAs from transmitting during the enhanced SP.

[0056] However, protection for overlapping BSS (OBSS) services is not considered, where adjacent BSSs operate in the same channel.

[0057] Multi-AP coordinated transmission schemes (especially those based on shared TXOPs) require target STAs in different BSSs to be simultaneously active or awake. This is not always possible, especially when STAs are operating in power-saving mode. Therefore, the problem is how to ensure that STAs in different BSSs participating in the coordinated transmission are simultaneously active or awake. Furthermore, another problem to be addressed is how to protect priority-ordering services (e.g., low-latency services or NSEP services) within the enhanced TWT by limiting channel access from the OBSS (from non-designated services).

[0058] refer to Figure 2 APs can negotiate a time period (coordination service period) during which they agree to perform multi-AP coordinated transmissions. For example, coordination SP negotiation between AP1 and AP2 occurs at SP negotiation 202. Such a coordination SP for multi-AP coordinated transmissions can include periodically repeating SPs, such as coordination SP 206 and coordination SP 208, in which the sharing AP (the AP that wins the shared TXOP) determines the actual multi-AP coordination scheme to be used within each coordination SP. Each AP, based on the actual multi-AP coordination scheme to be used within each coordination SP, determines the target STA from its associated STAs for transmissions during the coordination SP.

[0059] At 204, the STA negotiates the scheduling SP (BSS-specific) with its associated AP, or in some cases, the STA may have already negotiated the scheduling SP with its associated AP before SP negotiation 202. For example, STA1-1 and STA1-2 negotiate with AP1, while STA2-1 and STA2-2 negotiate with AP2. The AP assigns the STA to scheduling SPs 210 and 212, such that the STA's scheduling SP overlaps with the coordinating SP, thus ensuring that the STA is awake during each coordination transfer. The AP may also exchange next TBTT and beacon interval information 214 to ensure that the coordinating SP does not overlap with the AP's TBTT.

[0060] The scheduling SP used here refers to an SP existing between a STA and its associated AP, and can be any SP in which the STA and associated AP pre-negotiate one or more time periods to exchange frames. The STA is expected to be in a wake-up state or active mode during the SP, such as an S-APSD (Scheduled Automatic Power Save Delivery) SP, a Scheduled PSMP (Power Save Multi-poll) SP, a TWT (Target Wake Time) SP, a QTP (Quiet Time Period) SP, etc. Negotiation for a coordinated service period can be performed between two APs at a given time, but if a static shared AP / shared AP hierarchy exists, many shared APs can negotiate coordinated SPs with the same shared AP, and multiple shared APs can be assigned to the same coordinating SP (of the shared AP). Otherwise, each coordinated SP may exist between two APs. A shared AP is an AP that shares its Transmission Timing (TXOP) with another AP (shared AP).

[0061] The AP can negotiate the following parameters with respect to the coordinating SP:

[0062] - Start time of the first SP: The time when the first coordinated SP occurs.

[0063] -SP Duration: The duration of each coordinated SP

[0064] -SP Interval: The time interval between two consecutive coordinated SPs

[0065] - Number of Coordinating SPs: If greater than 1, this parameter indicates the total number of periodically repeating coordinating SPs. For example, this parameter may not exist if the coordinating SPs are persistent and occur periodically over the entire lifecycle of multi-AP coordination, or unless the coordinating SPs are explicitly terminated.

[0066] - The characteristics of the services expected to be exchanged during SP (data rate, burst size, latency limits, etc.) can optionally be included in the setup frame.

[0067] APs can also request that specific sub-parts of a SP be allocated to themselves, or they can exchange information about their timing synchronization function (TSF), next TBTT, and Beacon Interval (BI) to ensure that the coordinating SP does not overlap with the beacon transmission times of any AP. Once the coordinating SP is negotiated among APs, within each BSS, the selected STAs (i.e., vulnerable STAs expected to participate in the coordinated transmission) are assigned to scheduling SPs that overlap with the coordinating SP (e.g., S-APSD SP, TWT SP, etc.). STAs do not need to know about the coordinating SP. Advantageously, knowing the coordinating SP and the identifiers of the STAs participating in the coordinated transmission allows APs to better manage their scheduling.

[0068] Not all STAs benefit equally from coordinated transmissions. Some STAs may benefit more than others, and these STAs can be considered vulnerable. Which STA benefits the most also depends on the multi-AP coordination scheme. STAs that can benefit most from coordinated OFDMA should be identified before coordinated transmissions begin, i.e., STAs within the transmission range of multiple APs for C-OFDMA / C-TDMA, or STAs geographically dispersed for C-SR / C-BF. For example, see reference... Figure 3 STA2-1 and STA2-2 are associated with AP2 (BSS2), while STA1-1 and STA1-2 are associated with AP1 (BSS1). STA1-2 and STA2-2 can benefit most from C-SR / C-BF because they are far apart from each other, and simultaneous transmissions of both will not cause high levels of interference between them; while STA1-1 and STA2-1 benefit most from C-OFDMA / TDMA because these two STAs are very close to each other, so their transmissions cannot overlap in the frequency domain and / or time domain to avoid mutual interference.

[0069] The AP can collect reports (e.g., interference measurement reports) from associated STAs to identify vulnerable STAs. Typically, STAs operate in power-saving modes to conserve power, where each STA determines its own wake-up period (duty cycle). It is expected that the wake-up state of these STAs can be synchronized between OBSSs.

[0070] Not all STAs at the cell edge are equally affected by OBSS interference. In rare cases, even STAs at the cell center can be severely affected by OBSS interference. An AP can attempt to protect vulnerable STAs in its BSS from OBSS interference by "reserving" frequency units (RUs) for these STAs and making these RUs known to the OBSS AP. If all OBSS access points coordinate their transmissions so that they do not simultaneously transmit on reserved RUs at their neighboring access points, interference to vulnerable STAs can be largely avoided. The AP only "reserves" RUs for STAs that need protection from OBSS, such as vulnerable STAs. This subset of RUs can be referred to as the "reserved RU set" or the "protected RU set." The AP can use reports from its associated STAs to identify affected STAs and also determine the RUs in the "reserved RU set." For example, refer to... Figure 4 AP2 can identify STA3 as a "vulnerable STA" using bandwidth query reports (BQRs) or interference reports from the STA, and also select a reserved RU set for it. For the remaining STAs (such as...) Figure 4 STA1 may have no restrictions on RU selection. Interference reports from STAs can also identify interfering OBSS STAs; that is, STA2 can be identified as an interfering STA by STA3. Therefore, STA2 and STA3 can be identified as vulnerable STAs. The AP advertises the reserved RU set to other APs (either by broadcasting in beacons or via AP-to-AP links). Optionally, the AP can also report interfering OBSS STAs.

[0071] When selecting its own set of reserved RUs, the coordinating AP also considers the set of reserved RUs of neighboring BSSs. The set of reserved RUs is selected to have minimal overlap with the set of reserved RUs of neighboring BSSs. The RUs of those STAs reported as interfering STAs are also restricted to the set of reserved RUs.

[0072] EHT action frames can be defined as requests (by the AP) and reports (by the STA) of interference measurements. (Reference) Figure 5The AP can request interference measurements using EHT Interference Measurement Request Frame 502, and the STA can report interference measurements using EHT Interference Measurement Report Frame 504. If the interference originates from the UL in a non-AP STA, the Interference STA MAC Address subfield 506 can indicate the STA MAC address extracted from the TA (transmitter address) field of the interference frame; or if the interference originates from the DL to a non-AP STA, the Interference STA MAC Address subfield 506 can indicate the STA MAC address extracted from the RA (receiver address) field of the interference frame. The Interference BSSID subfield 508 can indicate the BSSID extracted from the BSSID field (typically address field 3) of the interference frame.

[0073] Instead of broadcasting, an AP can send a consolidated set of cell edge RUs or a reserved set of RUs to another AP via an AP-to-AP link, either directly as an action frame or encapsulated in a data frame (e.g., as an Ethernet 89-0d frame). This can be done as follows: Figure 6 The new AP coordination session action frame 600 shown is defined as carrying a reserved RU set element field 602 (with the same format as the cell edge RU set element, except that the cell edge RU set field is renamed to the reserved RU set field). The category field 604 may have an AP coordination session action field value of 6, indicating that the AP coordination session action frame 600 is for AP coordination of reserved RUs. Furthermore, the interfering STA list field 506 may list interfering STAs belonging to the target AP by their BSS, MAC address, or association identifier (AID). The reserved RU information is considered valid until the next "AP Coordinate Reserved RU" frame is sent. An AP may proactively send a reserved RU set to other APs, or the sending may be a response to a request from another AP.

[0074] In such Figure 7In the example of the coordinated transmission sequence shown, BSS1 and BSS2 can have different operating channels (same bandwidth but different start frequencies, different primary channels), but they overlap on CH3 and CH4. The reserved RU set of BSS1 is assigned to CH5 and CH6, while the reserved RU set of BSS2 is assigned to CH1 and CH2. There is ongoing UL MU PPDU transmission in BSS2; the RUs used for DL ​​transmissions to vulnerable STAs are in CH5 and CH6. The AP in BSS1 can solicit uplink transmissions by sending a TF frame, which assigns RUs to its vulnerable STAs on CH1 and CH2. The vulnerable STAs in BSS1 can then transmit their UL PPDUs on the RUs assigned in CH1 and CH2. Having a non-overlapping reserved RU set for vulnerable STAs helps minimize inter-BSS interference while improving space reuse.

[0075] Figure 8 Another example of a coordinated transmission sequence is shown. In this sequence, transmissions from multiple APs are coordinated, for example, by a multi-AP coordinator (i.e.,...). Figure 8 In a tightly coordinated multi-AP network (AP2), the timing of transmissions and the RUs (Remote Access Units) to be used for transmissions to / from vulnerable STAs can be determined by the multi-AP coordinator. AP2 sends a multi-AP trigger frame 802 to another AP (AP1) to initiate a coordinated uplink transmission. The multi-AP trigger frame 802 instructs AP1 to initiate a UL (Ultimate Link) transmission from STA2 and also assigns RU1 to be used for the UL transmission from STA2.

[0076] Following the SIFS (Short Interframe Space) interval, both AP2 and AP1 transmit a basic trigger frame 804. AP2 allocates RU2 for the UL transmission from STA3, and AP1 allocates RU1 for the UL transmission from STA2. After the SIFS interval, STA3 and STA2 transmit UL PPDU 806 on RU2 and RU1 respectively, thus avoiding any mutual interference. After the SIFS interval, AP2 and AP1 transmit block acknowledgments 808 on RU2 and RU1 respectively. Using this transmission sequence, the APs can dynamically coordinate their RU allocations to vulnerable STAs.

[0077] In one embodiment, a separate Target Wake-up Time (TWT) agreement can be negotiated as a coordinating SP between APs. The requesting AP can act as the TWT requesting STA, and the responding AP can act as the TWT responding STA. (See reference) Figure 9STA1-1 and STA1-2 are associated with AP1, STA2-1 and STA2-2 are associated with AP2, and STA3-1 is associated with AP3. Individual TWT agreements can be negotiated as a coordination SP 902 between APs. Coordination SP 902 can also be referred to as the Coordination TWT SP. Any AP assigned to the Coordination TWT SP (i.e., AP1, AP2, or AP3) can assume the role of a shared AP. APs can also send an unsolicited TWT setup response 906 to schedule another AP to join the Coordination SP. APs sending an unsolicited TWT setup response 906 can also include a list of APs already assigned / planned to be assigned to the same Coordination SP. Once the Coordination TWT SP has been negotiated, each AP can negotiate or renegotiate a new / existing scheduling SP 904 with a vulnerable STA, such that scheduling SP 904 overlaps with Coordination SP 902. The STA's scheduling SP 904 can be any SP where the STA and its associated AP pre-negotiate one or more time periods to exchange frames, and the STA is expected to be awake or active during that SP. Such SPs include S-APSD (Scheduled Automatic Power-Saving Delivery), Scheduled PSMP (Power-Saving Multi-Polling), TWT (Target Wake-Up Time), QTP (Quiet Time Period), etc. Figure 9 The diagram illustrates that STAs simultaneously negotiate a scheduling SP with their respective associated APs. However, in reality, these negotiations may occur at different times, and some STAs may have already negotiated the scheduling SP even before the APs set up the coordination SP. Within each coordination SP, the sharing AP decides on the multi-AP coordination scheme to use. For example, in the first coordination SP 902, the sharing AP AP1 decides to use C-OFDMA and shares the upper half of its operating bandwidth with AP2, such that AP1 and AP2 transmit to STA1-1 and STA2-1 on non-overlapping frequency channels (or RUs) during the first coordination SP, while AP3 does not participate in multi-AP coordination transmissions. In the second coordination SP, the sharing AP AP1 decides to use C-TDMA and allocates a sub-part of its TXOP to AP2 and AP3, such that during the second coordination SP, AP1, AP2, and AP3 transmit to their respective associated STAs STA1-1, STA2-1, and STA3-1 without overlapping their transmissions.

[0078] The TWT setup frame can be customized for multi-AP coordination. Figure 10An example of a TWT setup frame 1000 for setting up a TWT request / response for a coordinating SP is shown. Address 1 field (or A1 field) 1002 can indicate the MAC address of the target AP. Address 2 field (or A2 field) 1004 can indicate the MAC address of the requesting AP. Address 3 field (or A3 field) 1006 can be set to a special value (i.e., the virtual BSSID of the AP candidate set) if a special value exists; otherwise, it is set to the MAC address of the target AP. Since the TWT setup frame is not a public action frame, by default, the AP will reject such frames from STAs not associated with the AP. Thus, A3 field 1006 can be set to a special value (i.e., the virtual BSSID) known to all APs in the AP candidate set. TWT setup frames with the A3 field set to a special value will be accepted by APs in the AP candidate set. The AP can still perform further filtering based on TA; for example, if an AP candidate set exists, it can only accept frames from other APs in that set. Alternatively, the BSSID can be set to the BSSID of the receiving AP, and the receiving AP will accept the frame if the TA matches the MAC address of any AP in the AP candidate set. The AP candidate set is a set of APs that have performed basic negotiation and capability exchange and agreed to participate in multi-AP coordinated transmissions, either as a sharing AP (an AP that shares an acquired TXOP with another AP) or as a shared AP (the receiver of the shared TXOP). For the purposes of this disclosure, it is assumed that all participating APs are members of the AP candidate set. It is assumed that the APs have completed negotiation for forming the AP candidate set.

[0079] Since the timing synchronization function (TSF) of an AP is unlikely to be synchronized, the TSF offset / TSF value field 1008 can indicate the difference between the TSFs of two related requesting APs and receiving APs, or the value of the requesting AP's TSF at the time of transmission, to help the responding AP correctly calculate the requested target wake-up time. When determining the actual start time / duration of the coordinating SP, APs also take each other's TBTT and BI into account. The member AP list field 1010 in the TWT setting response frame can carry a list of MAC addresses of other APs also assigned to the same coordinating TWT SP. Furthermore, the reserved bits in TWT element 1012 (multi-AP coordination TWT subfield 1014) can be used to highlight that TWT element field 1012 is for coordinating SPs.

[0080] In such Figure 11In the example transmission shown, the scheduling SP for the STA can also be a TWT, for example, a triggered TWT SP. The STA's scheduling SP can start slightly earlier than the coordination SP to allow APs to check if they are awake, their buffer status, etc. The shared AP can pass this information to the sharing AP (e.g., at the beginning of the shared TXOP), and the sharing AP can use this information to determine which / which shared APs it shares the TXOP with. For example, at the beginning of the scheduling SP, each AP (i.e., AP1, AP2, and AP3) can optionally collect information about their associated STAs within their own BSS by sending a Buffer Status Report Poll Trigger frame (BSRP TF) 1102 to each associated STA, and each STA responds to the BSRP TF 1102 by sending the requested information to the associated STA. The sharing AP1 can then, for example, send a MAP Buffer Status Report Poll Trigger frame (BSRP TF) 1104 to the shared APs AP2 and AP3 at the beginning of the coordination SP1 to request information about their associated STAs. Then, AP2 and AP3 can each send a MAP BSR frame 1106 to AP1 in OFDMA mode to report the buffer status (UL and DL) of the STAs they have identified or associated with. For example, based on this report, if AP3 has significantly less buffered traffic than AP2, AP1 decides to share the TXOP with AP2 and therefore sends a MAP TF 1108 to AP2 to indicate AP1's intention to share the TXOP with AP2, along with relevant transmission parameters such as the RU assigned to AP2, transmission duration, MCS, TX power, etc. Following MAP TF 1108, AP1 and AP2 begin coordinating transmission, each sending DL PPDUs to STA1-1 and STA2-2 respectively in OFDMA mode. Subsequently, each STA sends an acknowledgment frame (e.g., a block acknowledgment frame) back to its associated AP. MAP BSR frame 1106 is also used to protect the coordinated transmission by setting the NAV of all STAs within AP1's transmission range.

[0081] Ethernet 89-0d data frames (such as...) Figure 12 Data frame 1200 in the 11ax framework can be used as a MAP-BSR frame (such as MAPBSR frame 1106) to share buffer status reports between APs. For example, the UL / DL field 1202 can indicate whether the report is for the DL buffer or the UL buffer. The queue size field 1204 can indicate an estimate of the total buffer size at the AP (for DL) / associated vulnerable STA (for UL) (using the same encoding as in 11ax).

[0082] In addition, AP or STA can use such as Figure 13 The EHT capability elements 1300 are shown to indicate the features they support. For example, the EHT MAC capability field 1302 may include an Enhanced TWT field 1304, which may indicate whether Enhanced TWT is supported. The EHT multi-AP capability field 1306 may include C-OFDMA, C-TDMA, C-SR, C-BF, and joint transmission fields, which can be used to indicate whether multi-AP transmission schemes are supported. The EHT multi-AP capability field 1306 may also include a Coordinated SP field 1308 and an SP Information Solicitation field 1310, whereby the Coordinated SP field 1308 indicates whether the relevant AP supports Coordinated SP, and the SP Information Solicitation field 1310 indicates whether the relevant AP supports soliciting information about SP.

[0083] TWT setup frames (used to set the coordination SP) can also be carried within Ethernet 89-0d data frames, such as... Figure 14 The 802.11 data frame 1400. For example, data frame 1400 may include one or more TWT element fields 1402 and a subtype field 1404, the TWT element field 1402 including information for setting the coordination SP, and the subtype field 1404 indicating that data frame 1400 is for TWT setting.

[0084] In various embodiments, the coordinating SP can specify a multi-AP coordination scheme (C-OFDMA / C-TDMA, C-SR / C-BF, joint transport, etc.) or permitted service types within the SP. For example, refer to... Figure 15 Coordinating SP1 1502 can be a coordinating SP for C-OFDMA / TDMA transmissions, while coordinating SP2 1504 can be a coordinating SP for C-SR / C-BF transmissions. STAs can then be assigned to scheduling SPs (specifically BSSs) located within suitable coordinating SPs to ensure they are awake during appropriate coordinated transmissions. This advantageously allows STAs to have greater power-saving gains and avoids unnecessary wake-ups during unsuitable coordinating SPs.

[0085] An AP can request another AP to set up a coordination SP for a specific type of MAP coordination scheme or for a specific type of service. During the SP negotiation phase, the requesting AP can also specify a desired 20 MHz sub-channel for itself for C-OFDMA; the responding AP can specify the assigned 20 MHz sub-channel for the requesting AP for C-OFDMA. Similarly, the requesting AP can specify a desired sub-slot within its SP for C-TDMA or priority-ordering services; the responding AP can specify the assigned sub-slot for the requesting AP. By sending a silence element or a silence channel element in the beacon / probe response frame, the AP can further protect sensitive services (e.g., low-latency services / NSEP services) from each AP's own associated STA during the sub-slot period, thus silencing the BSS channel during the sub-slot period.

[0086] New common action frames (such as Figure 16 Coordination SP request frame 1600 and Figure 18 The coordination SP response frame 1800 can be used to negotiate and coordinate an SP. For example, the coordination SP request frame 1600 may include a scheduling element field 1602 that can indicate the parameters of the requested SP. (See reference...) Figure 17 Table 1700, the scheduling element field 1602 may further include a scheduling information field 1604 that can indicate a coordination SP type value. For example, a coordination SP type value of 0 indicates that the coordination SP is for C-OFDMA, a coordination SP type value of 1 indicates that the coordination SP is for C-TDMA, and so on. Furthermore, the coordination SP response frame 1800 may include a status field 1802 that can indicate whether the request has been accepted or rejected. This frame may also include a scheduling element field 1804 that can indicate the agreed SP parameters used for coordination.

[0087] In one example, the baseline scheduling element (scheduling element 9.4.2.33 of IEEE 802.11-2020) can be reused to negotiate and coordinate SPs. For example, the service start time field of the baseline scheduling element indicates the expected time, in microseconds, when service begins, and is represented by the lower four octets of the TSF timer value at the start of the first SP. The service interval field indicates the time, in microseconds, between two consecutive SPs, and represents the measured time from the start of one SP to the start of the next SP. Furthermore, some reserved bits in the scheduling information field can be used to indicate the type of coordinated SP, i.e., the multi-AP coordination scheme to be executed within the coordinated SP. The canonical interval field can be reused to signal the number of coordinated SPs for periodically repeating coordinated SPs.

[0088] Alternatively, the TWT setup frame can be used to negotiate and coordinate the SP. (See reference) Figure 19An example TWT setup frame 1900, which can be used for TWT requests and responses to set up multi-AP coordination TWT SPs, may include one or more TWT element fields 1902. The TWT element fields 1902 include a coordination SP type field 1904 for specifying the multi-AP coordination scheme and / or allowed service types. For example, based on... Figure 17 Table 1700, the Coordination SP Type field 1904 can indicate a Coordination SP Type value to indicate the Coordination SP Type. The TWT Setup Frame 1900 may also include an eTSPEC field 1906 that can indicate service characteristics. For example, if the Coordination SP Type field 1904 indicates a service type, further characteristics of the service can be indicated in the eTSPEC field 1906.

[0089] For intra-BSS TWT negotiation, the TWT channel field (such as TWT channel field 1908) and extended TWT channel field (such as extended TWT channel field 1910) in the TWT element of the TWT setting frame are used together for HE / EHT sub-channel selective transmission. The TWT channel can be used to signal a secondary channel requested by an HE / EHT STA within the primary 160 MHz. The extended TWT channel can be used to signal a secondary channel requested by an EHT STA within the secondary 160 MHz. A 1-bit setting indicates a 20 MHz channel for a 20 MHz working STA, while all four least significant bits (LSBs) or all four most significant bits (MSBs) set to 1 indicate the first or second 80 MHz channel within the secondary 160 MHz.

[0090] In TWT negotiation for C-OFDMA MAP coordination SP, the TWT channel field and extended TWT channel field in the TWT element of the TWT setting frame are used together to signal the requested / assigned sub-channel to the AP during C-OFDMA MAP transmission. The TWT channel is used to signal the secondary channel requested by the AP within the primary 160 MHz range, with each bit representing a 20 MHz sub-channel. The extended TWT channel is used to signal the secondary channel requested by the AP within the secondary 160 MHz range, with each bit representing a 20 MHz sub-channel.

[0091] An AP can also request coordination with a sub-SP (i.e., a specific time slot) within a SP. A sub-SP can indicate a short period during which the AP needs quasi-guaranteed channel access (e.g., for low-latency services highly sensitive to jitter). [Reference] Figure 20In TWT negotiation for C-TDMA MAP coordination SPs or priority-ordering service coordination SPs, the TWT setting frame (i.e., such as...) Figure 20 The TWT element 2000 can also carry information related to the requested / assigned sub-SP (within the coordinating SP) during C-OFDMA MAP transmission:

[0092] - If set, the Non-Negotiable field 2002 indicates that the requested subSP start time cannot be changed.

[0093] The SubSP Start Offset Field 2004 is used to signal the time offset from the SP start time to the start of the requested / assigned subSP.

[0094] The SubSP Duration field 2006 is used to signal the duration of the requested / assigned SubSP.

[0095] The SubSP Interval field 2008 indicates the time interval between consecutive subSPs when the subSPs are also periodic.

[0096] If 11be decides not to allow mixed C-OFDMA and C-TDMA transmissions within the same MAP shared TXOP, it is also possible that when the coordinated SP type is C-TDMA, or if the coordinated SP type is reserved for priority ordering services, the TWT channel and extended TWT channel fields are reused as the sub-SP start offset field and sub-SP duration field.

[0097] Figure 21 Figure 2100 illustrates an example of a coordinated SP for C-TDMA. In this example, all STAs have low-latency services, and the negotiated coordinated SP type is low-latency. When negotiating a coordinated SP with AP1, AP2 and AP3 may also indicate sub-parts of the coordinated SP (called sub-SPs, such as sub-SP 2104) during which they need to provide quasi-guaranteed channel access for certain service types (e.g., for low-latency services that are highly sensitive to jitter). If the sub-SPs of the member APs of the coordinated SP do not overlap, the sharing APs may employ C-TDMA transmissions during the shared TXOP to make a best effort to provide the shared TXOP to each member AP during the sub-SPs they request. Each AP uses its assigned sub-SP 2104 to communicate with its respective associated STA. The sharing AP AP1 may retrieve any unused portions of the TXOP for transmissions to its own associated STAs, i.e., transmissions such as those used for DL-PPDU 2102.

[0098] If the sub-SPs of member APs coordinating a SP overlap, the sharing APs may not be able to cleanly share the TXOP using only C-TDMA during the shared TXOP period. In this case, the sharing APs can employ a hybrid C-TDMA and C-OFDMA transmission to make a best effort to provide the shared TXOP to each member AP during the sub-SP requested by the member APs, while ensuring that the member APs are assigned different sub-channels at least during the sub-SP period. For example, refer to... Figure 22 Figure 2200 illustrates a C-TDMA + C-OFDMA example. During the initial portion of the shared TXOP, the sharing AP AP1 uses the entire bandwidth to transmit to / from its associated STA via the C-TDMA portion 2204, and is assigned to other member APs of the coordinating SP during the second portion of the shared TXOP. For example, the sharing AP AP1 can send a MAP TF 2202 to the shared APs AP2 and AP3 to signal the C-TDMA parameters for the C-TDMA portion 2204. During the second portion of the TXOP, the sharing AP can further employ C-OFDMA and share the TXOP with member APs to allocate non-overlapping sub-channels to each member AP. To achieve this, the shared AP can send a second MAP TF 2206 at the end of its own C-TDMA portion 2204 of the TXOP to allocate sub-channels to member APs during the C-OFDMA portion 2208 of the shared TXOP; that is, allocating a minor 160 MHz channel to AP2 and a major 160 MHz channel to AP3 (assuming all APs operate on 320 MHz channels). Alternatively, if sub-channels have already been allocated during the coordination SP negotiation 2210 (e.g., using the TWT channel field and TWT extended channel field of the TWT element), the second MAP TF 2206 for C-OFDMA can be skipped, as each AP already knows its allocated sub-channels. Each shared AP, AP2 and AP3, uses the channels they have allocated within the sub-SP to communicate with their respective associated STAs. The shared APs may also opportunistically use any unused portions of the TXOP (in the time or frequency domain) for transmissions to their own associated STAs. In this example, all STAs have low-latency services, and the negotiated coordination SP type is low-latency.

[0099] In one embodiment, each AP can also advertise the coordinating SP to the STAs in the BSS; that is, the AP can overlay broadcast TWT SPs on the coordinating SPs and advertise them via the TWT element in the beacon frame. For example, refer to Figure 23In transmission diagram 2300, AP1 and AP2 can use beacon frame 2302 to set up broadcast TWT SPs that overlap with the coordinating SP. For example, they can set up an enhanced TWT SP set (broadcast TWT SP with ID 1) to overlap with coordinating SP1, and set up another enhanced TWT SP set (broadcast TWT SP with ID 2) to overlap with coordinating SP2. In this example, the APs do not need to identify the STA type; instead, the STAs can negotiate to join the broadcast TWT SPs of interest, i.e., at transmission section 2304. The STAs do not need to know about the existence of overlapping coordinating SPs. Therefore, the APs do not need to identify and micro-manage the STAs, because the STAs can subscribe to the SPs of interest. For example, STA1-1 and STA2-1, which have low-latency services to send, can negotiate to join the enhanced TWT SP (with broadcast TWT ID 1), while STA1-2 and STA2-2, which have NSEP services to send, can negotiate to join the enhanced TWT SP (with broadcast TWT ID 2).

[0100] In one embodiment, an AP can request scheduling SP information for its associated STA from a second AP, and use this information to schedule SPs for its own associated STAs, thereby reducing competition between priority-ordering services between OBSSs. (See reference) Figure 24 In transmission diagram 2400, APs in the AP candidate set exchange information about (existing and / or intended) enhanced TWT SPs and coordinate their enhanced TWT SPs so that the TWT SPs do not overlap in the time / frequency domain. For example, AP2 can request enhanced TWT information from AP1 and AP3 by sending SP information request 2402 to AP1 and SP information request 2404 to AP3, respectively. Using the enhanced TWT information from AP1 and AP3, AP2 can ensure that its own enhanced TWT SP (i.e., enhanced TWT SP 2406) does not overlap with the enhanced TWT SPs of AP1 / AP3 in time / frequency.

[0101] Information exchange between APs can be over the air (in-band) or on the backhaul link (wired / wireless) (out-of-band). Enhanced TWTs can be as defined in Singapore Patent Application No. 10202012139Q. While coordination can be for any TWT SP, enhanced TWT coordination can offer more benefits by ensuring that priority-ordering services (e.g., low-latency services) of the OBSS do not simultaneously compete for the channel. This implementation may be suitable for deployments where there is no strong relationship between APs (e.g., non-enterprise deployments) and the APs do not intend to share TXOPs.

[0102] While it's possible for an AP to decode another AP's beacon frame to gather information about that AP's broadcast enhanced SPs (if any) and passively adjust its own enhanced SPs (if necessary) to avoid overlap, individual TWT SPs are not advertised in beacon frames, so another AP might not be aware of an AP's individual TWT SPs. An AP can also request information about another AP's service periods (AP-coordinated SPs, or the scheduled SPs of an AP's STAs (broadcast SPs and individual SPs)). For example, an AP can request information about another AP's coordinated SPs, which it can use to request to join an interested coordinated SP. Alternatively, if needed, an AP can also request information about enhanced TWT SPs used for prioritizing services from another AP and adjust its own enhanced TWTs for prioritizing SPs so that the SPs of the two APs do not overlap. In managed networks (e.g., enterprise deployments), this coordination of SPs between APs can also be centrally managed, for example, by an AP controller (multiple APs). If a master / slave hierarchy exists between APs, the master AP can assist in the coordination of SPs between APs.

[0103] Data frames with a "ether-type 89-0d" frame body (such as...) Figure 25 Data frame 2500) or new common action frames (such as Figure 27 The TWT SP information request / response frame 2700 can be used to request AP service time information or to share AP service time information with other APs. Referring to data frame 2500, the TWT SP type field can indicate based on... Figure 26 The TWT SP type values ​​in Table 2600. For example, a TWT SP type value of 0 indicates that the SP coordinated by the AP is for C-OFDMA / C-TDMA, a value of 1 indicates that the SP coordinated by the AP is for C-SR / C-BF, and so on. Data frame 2500 may include zero or more TWT element fields 2504 and zero or more eTSPEC element fields 2506. The TWT element fields 2504 carry information about the TWT SP, and the eTSPEC element fields 2506 carry information about the characteristics of the services expected / permitted to be exchanged during the TWT SP.

[0104] refer to Figure 27 In TWT SP Message Request / Response Frame 2700, the following fields are always carried in the TWT SP Message Response Frame and may optionally be carried in the TWT SP Message Request Frame:

[0105] - Current TSF field 2702: Carries the AP's TSF value at the time of transmission to help the receiving AP calculate the target wake-up time (TWT SP).

[0106] -TWT element field 2704: Each TWT element carries information about a TWT SP for the sending AP.

[0107] In addition, the eTSPEC element field 2706 may optionally be carried in both frames. The eTSPEC element field 2706 carries information about the characteristics of the services that are expected / permitted to be exchanged during the TWT SP.

[0108] In one embodiment, an AP may also request to join an existing scheduling SP of another AP (e.g., a separate or broadcast TWP SP). Reference Figure 28 In the transmission diagram 2800, AP2 has set up a broadcast enhanced TWT SP (ID2) 2802 for its associated STAs (e.g., for low-latency services). AP1 and AP3 collect information about AP2's enhanced TWT SP by passively listening to AP2's beacon frames or by exchanging SP information request / response frames for low latency. AP1 and AP3 request to join AP2's broadcast TWT SP (ID2) 2802. During the TWT SP, AP2, knowing that AP1 and AP3 are also members of the TWT SP, can share its TXOP with AP1 and AP2, for example, for C-TDMA transmission.

[0109] An AP can also indicate its desired subchannel or subSP in a TWT setup request. In this case, the first AP requesting to join the TWT SP is the TWT requesting STA (or TWT scheduled STA), and the second AP accepting the request is the TWT responding STA (or TWT scheduling STA). During the TWT SP, the second AP is expected to act as the sharing AP, while the first AP will be the shared AP. The first AP should wait for the second AP to initiate a coordinated transmission at the beginning of the TWT SP and avoid attempting to gain access to the channel. In this example, there are four phases:

[0110] - Phase 1 (SP Information Collection Phase): AP1 and AP3 collect information from TWT SPs provided by AP2 (broadcast / individual TWT SPs for their associated STAs, or coordinated SPs for other APs).

[0111] - Phase 2 (AP-AP SP Joining Phase): AP1 and AP3 request to join one of AP2's Broadcast Enhanced TWT SPs (e.g., one reserved for low-latency services). AP1 and AP2 may also request sub-SPs within a TWT SP.

[0112] - Phase 3 (SP Request within BSS): If an SP does not yet exist within the BSS, AP1 and AP3 can set up SPs for their associated STAs. These SPs can benefit from MAP-coordinated transmissions, ensuring they reside within the TWT SPs of AP2, which AP1 and AP2 have already joined. If an AP requests any sub-SPs, the SP within the BSS overlaps with the sub-SPs. This can be achieved, for example, by the AP sending an unsolicited TWT setup response frame to the selected STAs if a new TWT SP needs to be set up, or by sending a TWT information frame to adjust the start time of an existing TWT SP.

[0113] - Phase 4 (MAP Coordination Transmission during TWT SP): AP2 initiates coordination transmission (e.g., C-TDMA / C-OFDMA, etc.) during TWT SP to allocate time / frequency resources for AP1 and AP3, for example, within a shared TXOP.

[0114] Figure 29 A TWT setup frame 2900 is shown that can be used to join an existing TWT SP of another AP via a separate TWT setting. Since the TWT setup frame is not a common action frame, a special exception can be made in the IEEE 802.11be specification to allow an AP to accept a TWT setup frame sent by another AP. Alternatively, a new common action frame equivalent to the TWT setup frame can be defined for AP-to-AP TWT settings. The TWT setup frame 2900 may include one or two TWT element fields 2902, which may include a control field 2904 and a TWT parameter information field 2908. The control field 2904 may include a multi-AP coordination TWT field 2906, and the TWT element field 2902 may use reserved bits to indicate that the TWT element is for AP-to-AP settings. TWT parameter information field 2908 may include: Extended TWT Channel field 2910, which can signal the request for (multiple) secondary channels within the secondary 160MHz; MAP Coordination Type field 2912, which can indicate the MAP coordination transmission scheme that can be used during TWT SP; SubSP Non-Negotiation field 2914 (if set), which can indicate that the requested subSP start time cannot be changed; SubSP Start Offset field 2916, which can signal the time offset from the SP start time to the start of the requested / assigned subSP; SubSP Duration field 2918, which can signal the duration of the requested or assigned subSP; and SubSP Interval field 2920, which can indicate the time interval between consecutive subSPs when the subSP is also periodic.

[0115] Alternatively, instead of action frames, TWT setup frames can also be encapsulated in Ethernet 89-0d data frames. This approach avoids defining new common action frames for AP-to-AP TWT setups. Instead of including its TSF value / TSF offset in the TWT setup request frame, the requesting AP can also calculate the target wake-up time of the TWT SP based on the responding AP's TSF, so that the target wake-up time field in the TWT element indicates the actual start time from the responding AP's perspective, without requiring further adjustment.

[0116] The SubSP Non-Negotiation Field 2914 can be set by the requesting AP to indicate to the responding AP that it needs a quasi-guaranteed time period during which the requesting AP should be able to access the channel with a very high probability. For example, such a request could be for low-latency services that are very sensitive to jitter. If the responding AP accepts the TWT request, it will ensure that the AP or its associated STA does not transmit during the subSP period. The SubSP Start Offset Field 2916 can indicate the time offset from the requested SP start time to the start of the requested / assigned subSP. Alternatively, this field can also indicate the actual TSF (of the responding AP) at which the first subSP is requested to begin.

[0117] In addition, the sub-SP duration field 2918 can indicate the duration of each sub-SP. The sub-SP interval field 2920 can indicate the time interval between consecutive sub-SPs when the sub-SPs are also periodic and more than one sub-SP occurs within the requested TWT SP.

[0118] Therefore, an AP can use TWT setting frame 2900 to join a separate scheduled SP of interest for another AP. Alternatively, broadcasting the TWT setting can also be used to join an AP's existing scheduled SP. For example, Figure 30 The TWT setup frame 3000 can be used in a manner similar to that discussed for the TWT setup frame 2900, enabling an AP to join other APs’ schedule broadcast SPs of interest.

[0119] Figure 31 Figure 3100 illustrates an example of using a sub-SP to protect sensitive services (e.g., jitter-sensitive low-latency services). The stages of this example are as follows:

[0120] Phase 1: STA2-2 has negotiated with AP2 for periodic TWT SP #20 for jitter-sensitive low-latency services. SPs are short in duration but occur frequently. Due to the jitter sensitivity of the services, AP2 needs to ensure that STA2-2's services are prioritized during SPs.

[0121] Phase 2A: AP2 requests to join AP1's broadcast TWT #1 at 3102.

[0122] - Phase 2B: AP2 request is assigned a non-negotiable subSP 3104 within TWT#1.

[0123] - Phase 3: At the beginning of TWT#1, since AP2 knows AP1's TWT SP#1, it waits for MAP TF 3106 from AP1.

[0124] - Phase 4: Within the TWT SP, AP1 (e.g., using C-TDMA) shares its TXOP with AP2 to ensure that AP2 can gain access to the medium for jitter-sensitive services during AP2's TWT#20 SP. Each AP can also protect the sub-SP by sending a silence element / silent channel element to its associated STA, causing the sub-SP to overlap with the silence period, thereby ensuring that third-party STAs do not transmit during the sub-SP.

[0125] - Phase 5: During TWT #20 SP, which overlaps with TWT #1 of AP1, AP2 sends / receives sensitive service 3108 to / from the associated STA.

[0126] It can be seen that the coordination of TWT SPs between APs allows APs (even within the acquired TXOP) to effectively coordinate their transmissions and helps mitigate the adverse effects of OBSS transmissions on jitter-sensitive services.

[0127] In example diagram 3100, it is assumed that AP2 has already collected this information from AP1 by passively listening to AP1's beacon frames or by actively probing AP1's TWT SP information using SP information request / response frames. STA1-1 and STA2-1 are associated with AP1 and AP2, respectively. Since AP1's TWT SP #1 and AP2's TWT SP #20 may have different periodicities (determined by the TWT wake-up interval of each TWT agreement), the start time of the requested sub-SP may not be constant but varies depending on the occurrence of different TWT SP #1s. AP1 needs to calculate the start time of the sub-SP at the start of each new TWT SP #1 to ensure that they are aligned with AP2's TWT SP #20. Alternatively, before each new instance of TWT SP #1, AP2 may (e.g., using TWT information frames) inform AP1 of the correct start time of its requested sub-SP. AP1 and AP2 can further protect jitter-sensitive services from the associated STAs of each AP by sending a silence element or a silence channel element in the beacon / probe response frame, so that the BSS channel is silenced during the non-negotiable sub-SP.

[0128] Figure 32The diagram illustrates configurations of a communication device 3200 according to various embodiments, such as a communication apparatus, a shared access point (AP), or a shared access point. The communication device 3200 may include at least one antenna 3201 for transmitting and receiving signals (for simplicity, in...). Figure 32 (Only one antenna is shown in the diagram). The communication device may include a wired I / F (interface) module 3212, a wireless I / F module 3202, a power supply 3220, at least one memory 3218, and a central processing unit (CPU) 3214 including at least one processor and at least one auxiliary storage device 3216. The wireless I / F module 3202 may also include a MAC sublayer 3206 and a PHY sublayer 3204. The MAC sublayer 3206 includes a service session management module 3208, which manages service sessions for associated STAs and stores records of all such STAs in a record of coordinated service sessions 3210. The wireless I / F module 3202, CPU 3214, at least one memory 3218, and at least one auxiliary storage device 3216 can be used together as circuitry for a communication device 3200 for coordinating and prioritizing services (i.e., low-latency services) as described in this application. This circuitry generates TWT request frames, response frames, trigger frames, multi-STA block acknowledgment frames, DL MUPPDUs, beacon frames, DL PPDUs, frames including TWT elements, RTS / CTS frames, TWT information frames, NSEP response frames, NSEP frames, and TWT setting frames. The antenna 3201 can then transmit the generated frames or PPDUs to other communication devices (e.g., multiple STAs). Antenna 3201 can receive TWT request frames, response frames, PS-Poll frames, QoS empty frames, block acknowledgment frames, TB PPDUs (i.e., UL PPDUs), CTS frames, NSEP request frames, NSEP frames, and TWT setting frames from other communication devices (i.e., multiple STAs used for the coordination and prioritization services (i.e., low-latency services) described in this disclosure). The circuitry of communication device 3200 can then process the received frames or PPDUs.

[0129] Figure 33 The diagram illustrates a configuration of a communication device 3300 according to various embodiments, such as a communication apparatus, for example, a non-APSTA. The communication device 3300 may include at least one antenna 3301 for transmitting and receiving signals (for simplicity, in...). Figure 33(Only one antenna is shown in the image). The communication device may include a wired I / F module 3312, a wireless I / F module 3302, a power supply 3320, at least one memory 3318, and a central processing unit (CPU) 3314 including at least one processor and at least one auxiliary memory 3316. The wireless I / F module 3302 may also include a MAC sublayer 3306 and a PHY sublayer 3304. The MAC sublayer 3306 includes a service session management module 3308, which manages the service sessions that the communication device 3300 is a member of and stores records of all such service sessions in a record of coordinated service sessions 3310. The wireless I / F module 3302, CPU 3314, at least one memory 3318, and at least one auxiliary memory 3316 can be used together as circuitry for a communication device 3300 for coordinating and prioritizing services (i.e., low-latency services) as described in this disclosure, generating TWT request frames, response frames, PS-Poll frames, QoS empty frames, block acknowledgment frames, TB PPDUs (i.e., UL PPDUs), CTS frames, NSEP request frames, NSEP frames, and TWT setting frames. The antenna 3301 can then transmit the generated frames or PPDUs to other communication devices, such as multiple access points (APs). Antenna 3301 can receive TWT response frames, trigger frames, multi-STA block acknowledgment frames, DL MUPPDUs, beacon frames, DL PPDUs, frames including TWT elements, RTS / CTS frames, TWT information frames, NSEP response frames, NSEP frames, and TWT setting frames from other communication devices (i.e., multiple APs used for coordination services and priority ordering services (i.e., low-latency services) as described in this disclosure). The circuitry of communication device 3300 can then process the received frames or PPDUs.

[0130] Figure 34 A flowchart 3400 illustrating a communication method according to various embodiments is shown. In step 3402, a frame indicating a request to set up one or more coordinating SPs is generated. In step 3404, the frame is sent to the AP.

[0131] Figure 35 A schematic partial cross-sectional view of a communication device 3500 that can be implemented for coordinating a Service Provider (SP) is shown. According to various embodiments, the communication device 3500 can be implemented as a shared Access Point (AP), a shared AP, or an associated Service Provider (STA).

[0132] The various functions and operations of the communication device 3500 are arranged into multiple layers according to a hierarchical model. In this model, lower layers report to and receive instructions from higher layers according to IEEE specifications. For simplicity, the details of the hierarchical model are not discussed in this disclosure.

[0133] like Figure 35 As shown, the communication device 3500 may include circuitry 3514, at least one radio transmitter 3502, at least one radio receiver 3504, and multiple antennas 3512 (for simplicity and for illustrative purposes, in...). Figure 35 (Only one antenna is depicted in the diagram). The circuit may include at least one controller 3506, which is used for software and hardware to assist in the execution of tasks designed to be performed, including controlling communication with one or more other multi-link devices in a MIMO wireless network. The at least one controller 3506 may control: at least one transmit signal generator 3508 for generating frames to be transmitted to one or more other STAs, APs, or AP multi-link devices (MLDs) via at least one radio transmitter 3502; and at least one receive signal processor 3510 for processing frames received from one or more other STAs, APs, or AP MLDs via at least one radio receiver 3504. The at least one transmit signal generator 3508 and the at least one receive signal processor 3510 may be separate modules of the communication device 3500, communicating with the at least one controller 3506 for the aforementioned functions. Alternatively, the at least one transmit signal generator 3508 and the at least one receive signal processor 3510 may be included within the at least one controller 3506. It will be apparent to those skilled in the art that the arrangement of these functional modules is flexible and may vary depending on actual needs and / or requirements. Data processing, storage, and other related control devices can be provided on appropriate circuit boards and / or in chipsets.

[0134] In various embodiments, at least one radio transmitter 3502, at least one radio receiver 3504, and at least one antenna 3512 may be controlled by at least one controller 3506. Furthermore, although only one radio transmitter 3502 is shown, it should be understood that there may be more than one such transmitter.

[0135] In various embodiments, at least one radio receiver 3504, together with at least one receive signal processor 3510, forms the receiver of the communication device 3500. The receiver of the communication device 3500 provides the functionality required for multi-link communication. Although only one radio receiver 3504 is shown, it should be understood that there may be more than one such receiver.

[0136] Communication device 3500 provides the functionality required to coordinate SPs. For example, communication device 3500 may be a first AP. Circuit 3514 may generate a request frame indicating a request to set up one or more coordinated SPs. Transmitter 3502 may send the request frame to a second AP.

[0137] Receiver 3504 can receive a response frame from the second AP indicating acceptance of a request to set one or more coordinating SPs; wherein transmitter 3502 can also send frames to one or more associated STAs to set scheduling SPs that overlap with the coordinating SPs. The request frame, response frame, and the frames can be TWT setting frames, and the coordinating SP can be a TWT SP. The TWT setting frame carries an indication that the coordinating SP is used for multi-AP coordinated transmission, and also carries the Timing Synchronization Function (TSF) value of the AP sending the TWT setting frame. The TWT setting frame received from the second AP can also carry identification information of one or more other APs that are also members of the coordinating SP. The TWT setting frame can indicate, in the TWT channel field and TWT extended channel field of the TWT element of each TWT setting frame, a sub-channel requested by the first AP or assigned to the first AP by the second AP, the sub-channel being a subset of the second AP's working channels. The TWT setting frame can indicate, in the TWT element of each TWT setting frame, the start time offset, duration, and interval of one or more sub-SPs requested by the first AP or assigned to the first AP by the second AP, the sub-SP being part of the coordinating SP. The first AP can be the only AP permitted by the second AP to transmit in the assigned sub-channel or in the assigned sub-SP during a shared TXOP of a multi-AP coordinated transmission initiated by the second AP.

[0138] The first AP can also participate in a shared TXOP of a multi-AP coordinated transmission initiated by the second AP within a coordinating SP, wherein the transmitter 3502 of the first AP can also send frames to its associated STAs in a coordinated manner with the second AP. The transmitter 3502 can also send frames to the second AP at the beginning of the shared TXOP reporting the DL and UL buffer status of its BSS. The multi-AP coordinated transmission can be one of C-OFDMA, C-TDMA, C-SR, C-BF, or coordinated MU-MIMO transmission. Circuit 3514 can also determine the appropriate type of multi-AP coordinated transmission for each associated STA, wherein the transmitter 3502 can also send frames to the associated STAs based on the determined multi-AP coordinated transmission type to set the scheduling SP overlapping with the corresponding coordinating SP; the request frame and the frame are TWT setting frames. The TWT setting frames can indicate, in the TWT channel field and TWT extended channel field of the TWT element of each TWT setting frame, a sub-channel requested by the first AP or assigned to the first AP by the second AP, the sub-channel being a subset of the second AP's working channels. The TWT setup frame can indicate the start time offset, duration, and interval of one or more sub-SPs requested by the first AP or assigned to the first AP by the second AP in the TWT element of each TWT setup frame. The sub-SPs are part of the coordinated SP. The first AP can be the only AP permitted by the second AP to transmit in the assigned sub-SPs in the assigned sub-channel or during a shared TXOP of a multi-AP coordinated transmission initiated by the second AP.

[0139] Receiver 3504 can receive frames transmitted by the second AP, which are beacon frames, action frames, or data frames; and circuitry 3514 can also extract information about SPs associated with the second AP from the received frames. The SP can be a TWT SP. Transmitter 3502 can also send TWT setup request frames to the second AP to request one or more associated SPs to join the second AP. Transmitter 3502 can also send frames to one or more associated STAs to set up scheduled SPs that do not overlap with the associated SPs of the second AP. The TWT setup frame can indicate, in the TWT channel field and TWT extended channel field of the TWT element of each TWT setup frame, a sub-channel requested by the first AP or assigned to the first AP by the second AP, the sub-channel being a subset of the second AP's operating channels. The TWT setup frame can also indicate, in the TWT element of each TWT setup frame, the start time offset, duration, and interval of one or more sub-SPs requested by the first AP or assigned to the first AP by the second AP, the sub-SP being part of a coordinated SP. The first AP can be the only AP permitted by the second AP to transmit in the assigned sub-channel or during a shared TXOP of a multi-AP coordinated transmission initiated by the second AP for the assigned sub-SP.

[0140] Communication device 3500 can be a non-AP STA. Receiver 3504 can receive either a beacon frame or an action frame from its associated AP. Circuitry 3514 can extract SP information for coordinating transmissions from this frame. Transmitter 3502 can send a request frame to the AP indicating a request to join the SP. The SP can be a TWT SP, and the request frame can be a TWT setup request frame.

[0141] This disclosure can be implemented through software, hardware, or a combination of both. Each functional block used in the description of each of the above embodiments can be implemented in part or in whole by an LSI (Large Scale Integrated circuit), such as an integrated circuit, and each process described in each embodiment can be controlled in part or in whole by the same LSI or a combination of LSIs. An LSI can be formed as a chip on its own, or a chip can be formed to include some or all of the functional blocks. An LSI may include data input terminals and output terminals coupled thereto. Depending on the level of integration, the LSI here may be referred to as an IC, a system LSI, a super LSI, or an ultra-LSI. However, the technology for implementing integrated circuits is not limited to LSIs and can be implemented using dedicated circuits, general-purpose processors, or special-purpose processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after the LSI is manufactured, or reconfigurable processors in which the connections and settings of circuit cells disposed within the LSI can be reconfigured, can be used. This disclosure can be implemented as digital or analog processing. If future integrated circuit technologies replace LSIs due to advancements in semiconductor technology or other derivative technologies, future integrated circuit technologies can be used to integrate the functional blocks. Biotechnology can also be applied.

[0142] This disclosure can be implemented by any kind of communication-enabled device, apparatus or system, which is referred to as a communication device.

[0143] Some non-limiting examples of such communication devices include telephones (e.g., cellular phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital cameras / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, remote health / telemedicine (remote health and medical) devices, and vehicles that provide communication capabilities (e.g., cars, airplanes, ships) and various combinations thereof.

[0144] Communication devices are not limited to portable or mobile devices, but may also include any kind of non-portable or fixed devices, equipment or systems, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines, and any other “things” in an “Internet of Things (IoT)” network.

[0145] Communication can include exchanging data through, for example, cellular systems, wireless LAN systems, satellite systems, and various combinations thereof.

[0146] The communication device may include means, such as a controller or sensor, coupled to a communication means that performs the communication functions described in this disclosure. For example, the communication device may include a controller or sensor that generates control signals or data signals used by the communication means that performs the communication functions of the communication device.

[0147] Communication equipment may also include infrastructure such as base stations, access points, and any other devices, equipment, or systems that communicate with or control such devices as those in the non-limiting examples above.

[0148] A non-limiting example of a station may be a station included in a first plurality of stations attached to a multi-link station logical entity (i.e., an AP MLD), wherein, as part of the first plurality of stations attached to the multi-link station logical entity, the stations in the first plurality of stations share a common media access control (MAC) data service interface at the upper layer, wherein the common MAC data service interface is associated with a common MAC address or service identifier (TID).

[0149] The following statements are described in this disclosure:

[0150] Statement 1: A first access point (AP) includes:

[0151] The circuit generates a request frame indicating a request to set one or more Coordination Service Periods (SPs); and

[0152] The transmitter sends a request frame to the second AP.

[0153] Statement 2: The first AP according to Statement 1 further includes a receiver that receives a response frame from the second AP, the response frame indicating acceptance of a request to set one or more coordinating SPs; wherein the transmitter also sends frames to one or more associated stations (STAs) to set scheduling SPs that overlap with the coordinating SPs.

[0154] Statement 3: According to the first AP described in Statement 2, the request frame, the response frame, and the frame are target wait time (TWT) setting frames, and the coordinating SP is a TWT SP.

[0155] Statement 4: According to the first AP described in Statement 3, the TWT setup frame carries the Coordination SP as an indication for multi-AP coordinated transmission, and also carries the Timing Synchronization Function (TSF) value of the AP that sent the TWT setup frame.

[0156] Statement 5: According to the first AP described in Statement 3, the TWT setting frame received from the second AP also carries identification information of one or more other APs that are also members of the coordinating SP.

[0157] Statement 6: According to the first AP described in Statement 1, wherein the first AP also participates in a shared TXOP of multi-AP coordinated transmission initiated by the second AP within the coordinating SP, and wherein the transmitter of the first AP also transmits frames to its associated STA in a manner coordinated with the second AP.

[0158] Statement 7: According to the first AP as described in Statement 6, the transmitter also sends a frame to the second AP at the beginning of the shared TXOP reporting the downlink (DL) and uplink (UL) buffer status of its Basic Service Set (BSS).

[0159] Statement 8: According to the first AP described in Statement 6, the multi-AP coordinated transmission is one of coordinated orthogonal frequency division multiple access (OFDMA) transmission, coordinated time division multiple access (TDMA) transmission, coordinated spatial reuse (SR) transmission, coordinated beamforming (BF) transmission, or coordinated multi-user multiple-input multiple-output (MU-MIMO) transmission.

[0160] Statement 9: According to the first AP described in Statement 8, wherein the circuit further determines an appropriate type of multi-AP coordination transmission for each associated STA, and wherein the transmitter further sends a frame to the associated STA based on the determined multi-AP coordination transmission type to set a scheduling SP overlapping with the corresponding coordination SP, the request frame and the frame being a TWT setting frame.

[0161] Statement 10: The first AP according to Statement 1 further includes a receiver that receives a frame sent by the second AP, the frame being one of a beacon frame, an action frame, or a data frame; and wherein the circuitry also extracts information of the SP associated with the second AP from the received frame.

[0162] Statement 11: The first AP as described in Statement 10, wherein SP is TWT SP.

[0163] Statement 12: According to the first AP as described in Statement 11, the transmitter also sends a TWT setup request frame to the second AP for requesting one or more associated SPs to join the second AP.

[0164] Statement 13: According to the first AP as described in Statement 10, the transmitter also sends frames to one or more associated STAs to set up scheduling SPs that do not overlap with the associated SPs of the second AP.

[0165] Statement 14: According to the first AP as described in statements 3, 9 and 12, wherein the TWT setting frame indicates, in the TWT channel field and TWT extended channel field of the TWT element of each TWT setting frame, a subchannel requested by the first AP or assigned to the first AP by the second AP, which is a subset of the working channels of the second AP.

[0166] Statement 15: The first AP as described in Statements 3, 9 and 12, wherein the TWT setting frame indicates in the TWT element of each TWT setting frame the start time offset, duration and interval of one or more sub-SPs requested by the first AP or assigned to the first AP by the second AP, the sub-SP being part of a coordinating SP.

[0167] Statement 16: The first AP as described in Statements 14 and 15, wherein the first AP is the only AP permitted by the second AP for transmission in the assigned sub-channel or in the assigned sub-SP during a shared TXOP of a multi-AP coordinated transmission initiated by the second AP.

[0168] Statement 17: A non-AP STA comprising:

[0169] The receiver receives either a beacon frame or an action frame from its associated AP;

[0170] The circuit extracts SP information for coordinating transmission from the frame; and

[0171] The transmitter sends a request frame to the AP, which indicates a request to join the SP.

[0172] Statement 18: The non-AP STA as described in Statement 17, wherein the SP is a TWT SP and the request frame is a TWT setup request frame.

[0173] Statement 19: A method comprising:

[0174] Generate a request frame indicating a request to set one or more Coordination Service Hours (SPs); and

[0175] Send a request frame to the AP.

[0176] Therefore, it can be seen that this embodiment provides a communication device and method for coordinating SPs.

[0177] While exemplary embodiments have been presented in the foregoing detailed descriptions of these embodiments, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiments are examples and are not intended to limit the scope, applicability, operation, or configuration of this disclosure in any way. Rather, the foregoing detailed descriptions will provide those skilled in the art with a detailed plan for facilitating the implementation of the exemplary embodiments. It should be understood that various changes can be made to the functionality and arrangement of the operating methods and steps described in the exemplary embodiments, as well as the modules and structure of the device described in the exemplary embodiments, without departing from the scope of the subject matter set forth in the appended claims.

Claims

1. A first access point (AP), comprising: The circuit generates a request frame that initiates negotiation between the first AP and the second AP for one or more service time slots (SPs). as well as The transmitter sends the request frame to the second AP. The second AP sends control frames to one or more STAs associated with the second AP. The control frame includes a TWT element that indicates the broadcast TWT and TWT wake-up interval of the first AP.

2. The first AP of claim 1, further comprising a receiver that receives a response frame from the second AP, the response frame being transmitted in response to the request frame; wherein, The transmitter also sends frames to one or more associated stations (STAs) to set up scheduling SPs that overlap with the SP.

3. The first AP of claim 2, wherein, The request frame and the response frame are target wait time (TWT) setting frames, and the SP is a TWT SP.

4. The first AP of claim 3, wherein, The TWT setup frame carries an indication that the SP is for multi-AP coordinated transmission, and also carries the timing synchronization function TSF value of the AP that sent the TWT setup frame.

5. The first AP of claim 3, wherein, The TWT setting frame received from the second AP also carries identification information of one or more other APs that are also members of the SP.

6. The first AP according to claim 1, wherein, The first AP also participates in the shared TXOP of the multi-AP coordinated transmission initiated by the second AP within the coordinating SP, and wherein the transmitter of the first AP also sends frames to its associated STA in a manner coordinated with the second AP.

7. The first AP according to claim 6, wherein, The transmitter also sends a frame at the beginning of the shared TXOP to the second AP reporting the downlink DL and uplink UL buffer status of its Basic Service Set (BSS).

8. The first AP according to claim 6, wherein, The multi-AP coordinated transmission is one of the following: coordinated orthogonal frequency division multiple access (OFDMA) transmission, coordinated time division multiple access (TDMA) transmission, coordinated spatial reuse (SR) transmission, coordinated beamforming (BF) transmission, or coordinated multi-user multiple input multiple output (MU-MIMO) transmission.

9. The first AP according to claim 8, wherein, The circuit also determines the appropriate type of multi-AP coordination transmission for each associated STA, and wherein the transmitter also sends a TWT setting frame to the associated STA based on the determined multi-AP coordination transmission type to set the scheduling SP that overlaps with the corresponding coordination SP.

10. The first AP according to claim 1, further comprising a receiver, the receiver receiving a frame transmitted by the second AP, the frame being one of a beacon frame, an action frame, or a data frame; and wherein, The circuit also extracts information about the SP associated with the second AP from the received frames.

11. The first AP according to claim 10, wherein, The SP is a TWT SP.

12. The first AP according to claim 11, wherein, The transmitter also sends a TWT setup request frame to the second AP to request one or more associated SPs to join the second AP.

13. The first AP according to claim 10, wherein, The transmitter also sends frames to one or more associated STAs to set up scheduling SPs that do not overlap with the associated SPs of the second AP.

14. The first AP according to claim 1, wherein, The control frame is a beacon frame.

15. The first AP according to claim 1, wherein, It also includes a receiver that receives a response frame sent from the second AP in response to the request frame, wherein the request frame and the response frame are common action frames or new action frames.

16. The first AP according to claim 1, wherein, The request frame includes information about the target wake-up time, the TWT wake-up interval last digit, and the nominal minimum TWT wake-up duration.

17. The first AP according to claim 1, wherein, The request frame includes the identification information of the second AP.

18. A communication method performed by an access point (AP), comprising: Generate a request frame to initiate negotiation between the first AP and the second AP for one or more service time slots (SPs). Send the request frame to the second AP; as well as Send control frames to one or more STAs associated with the second AP. The control frame includes a TWT element that indicates the broadcast TWT and TWT wake-up interval of the first AP.

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