Communication apparatus and communication method for multiple-access-point coordination

Abstract

The present disclosure provides a communication apparatus and a communication method for multiple-access-point (multi-AP or M-AP) coordination. The communication apparatus may be an access point (AP) comprising: circuitry, which in operation, generates a first frame within a time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; and a transmitter, which in operation, transmits the first frame to a second AP.

Description

[0001] Description

[0002] Title of Invention: COMMUNICATION APPARATUS AND COMMUNICATION METHOD FOR MULTIPLE-ACCESS-POINT COORDINATION

[0003] TECHNICAL FIELD

[0004] [1] The present disclosure relates to communication apparatuses and methods for multiple-access-point (multi-AP or M-AP) coordination, and more particularly, for sending information or a request relating to resources for multi-AP coordination.

[0005] BACKGROUND

[0006] [2] In I EEE 802.11, multiple-access-point (multi-AP or M-AP) coordination is being considered as an important feature to increase throughput and reliability. M-AP schemes under consideration include coordinated time-division multiple access (C-TDMA), coordinated orthogonal frequency-division multiple access (C-OFDMA), coordinated spatial reuse (C-SR), coordinated beamforming (C-BF). Among the many discussed M- AP coordination schemes, C-TDMA mainly considers a sharing AP (an AP that share resources with another AP as part of M-AP coordination) allocating a time resource to a shared AP (an AP that be shared resources by a sharing AP as part of M-AP coordination) and the sharing AP transmitting / receiving data in the allocated time resource using the resource’s bandwidth. C-OFDMA mainly considers a sharing AP allocating a frequency resource to a shared AP and the sharing AP transmitting / receiving data in the allocated time resource using the resource’s bandwidth.

[0007] [3] However, for multi-AP coordination, an AP may allocate unnecessary, too much, or too little resources to another AP. The optimization of such allocation has not been discussed.

[0008] [4] Therefore, there is a need for a communication apparatus and method for multiple- access-point (multi-AP or M-AP) coordination to address the issues, more particularly, to optimize resource allocation for multi-AP coordination. [5] Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.

[0009] SUMMARY

[0010] [6] Non-limiting and exemplary embodiments facilitate providing communication apparatuses and communication methods for subcarriers modulation across multiple spatial streams in context of WLAN.

[0011] [7] In an embodiment, the present disclosure provides a first access point (AP) comprising: circuitry, which in operation, generates a first frame within a time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; and a transmitter, which in operation, transmits the first frame to a second AP.

[0012] [8] In another embodiment, the present disclosure provides a second AP comprising: a receiver, which in operation, receives a first frame from a first AP of one or more first APs within a time period, the first frame comprising a first signal field indicating a time or frequency resource to exchange data in a basic service set (BSS) of the first AP; circuitry, which in operation, processes the first frame; and a transmitter, which in operation, further transmits a second frame to the first AP, the second frame allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0013] [9] In one embodiment, the present disclosure provides a communication method implemented by a first AP, comprising: generating a first frame within a time period, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; and transmitting the first frame to a second AP.

[0014]

[0010] In yet another embodiment, the present disclosure provides a communication method implemented by a second AP, comprising: receiving a first frame from a first AP of one or more first APs within a time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; processing the first frame; and transmitting a second frame to the first AP, the second frame allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0015]

[0011] It should be noted that general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0016]

[0012] Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and / or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and / or advantages.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018]

[0013] Embodiments of the disclosure will be better understood and readily apparent to one of ordinary skilled in the art from the following written description, by way of example only, and in conjunction with the drawings, in which:

[0019]

[0014] Figure 1 shows a schematic diagram illustrating a transmission opportunity (TXOP) sharing (TXS) procedure in C-TDMA involving a sharing access point (AP) and a single shared AP.

[0020]

[0015] Figure 2 shows a schematic diagram illustrating a TXOP sharing procedure in C-TDMA involving a sharing AP and multiple shared APs.

[0021]

[0016] Figure 3 shows a schematic diagram illustrating a communication apparatus according to various embodiments of the present disclosure.

[0022]

[0017] Figure 4 shows a flowchart illustrating a communication method for M-AP coordination according to various embodiments of the present disclosure.

[0023]

[0018] Figure 5 shows a flowchart illustrating another communication method for M-AP according to various embodiments of the present disclosure.

[0024]

[0019] Figure 6 shows a schematic diagram illustrating communications between two APs for M-AP coordination according to various embodiments of the present disclosure.

[0020] Figure 7 shows a schematic diagram illustrating communications between two APs for M-AP coordination according to a first embodiment of the present disclosure.

[0025]

[0021] Figure 8 shows a schematic diagram illustrating a TXOP sharing procedure according to a first variant of the first embodiment of the present disclosure.

[0026]

[0022] Figure 9 shows a schematic diagram illustrating another TXOP sharing procedure according to the first variant of the first embodiment of the present disclosure.

[0027]

[0023] Figure 10 shows an example format of a Common Info field in a Required TXOP Report Poll (RTRP) frame according to an embodiment of the present disclosure.

[0028]

[0024] Figure 11 shows an example format of a User Info list field in an RTRP frame according to an embodiment of the present disclosure.

[0029]

[0025] Figure 12 shows an example format of an RTR (Required TXOP Report) frame according to an embodiment of the present disclosure.

[0030]

[0026] Figure 13 shows an example format of a Control Information subfield in a Control List subfield of a HT Control field of an RTR frame according to an embodiment of the present disclosure.

[0031]

[0027] Figure 14 shows an example format of a multi-user request-to-send transmission opportunity (TXOP) sharing (MU-RTS TXS) trigger frame according to an embodiment of the present disclosure.

[0032]

[0028] Figure 15 shows a schematic diagram illustrating a TXOP sharing procedure according to a second variant of the first embodiment of the present disclosure.

[0033]

[0029] Figure 16 shows an example format of an element in an RTRP frame according to an embodiment of the present disclosure.

[0034]

[0030] Figure 17 shows a schematic diagram illustrating TXOP sharing procedures according to a third variant of the first embodiment of the present disclosure.

[0035]

[0031] Figure 18 shows a schematic diagram illustrating TXOP sharing procedures according to a fourth variant of the first embodiment of the present disclosure.

[0032] Figure 19 shows a schematic diagram illustrating a TXOP sharing procedure according to a second embodiment of the present disclosure.

[0036]

[0033] Figure 20 shows a schematic diagram illustrating a channel sharing procedure according to a first variant of a third embodiment of the present disclosure.

[0037]

[0034] Figure 21 shows a schematic diagram illustrating a channel sharing procedure according to a second variant of the third embodiment of the present disclosure.

[0038]

[0035] Figure 22 shows a schematic diagram illustrating channel sharing procedures according to a third variant of the third embodiment of the present disclosure.

[0039]

[0036] Figure 23 shows a schematic diagram illustrating channel sharing procedures according to a fourth variant of the third embodiment of the present disclosure.

[0040]

[0037] Figure 24 shows a schematic diagram illustrating a channel sharing procedure according to a fifth variant of the third embodiment of the present disclosure.

[0041]

[0038] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been depicted to scale. For example, the dimensions of some of the elements in the illustrations, block diagrams or flow charts may be exaggerated in respect to other elements to help provide an accurate understanding of the present embodiments.

[0042] DETAILED DESCRIPTION

[0043]

[0039] Some embodiments of the present disclosure will be described, byway of example only, with reference to the drawings. Like reference numerals and characters in the drawings may refer to like elements or equivalents.

[0044]

[0040] In the following paragraphs, certain exemplifying embodiments are explained with reference to an access point (AP) and a station (STA) for subcarriers modulation across multiple spatial streams, especially in a multiple-input multiple-output (MIMO) wireless network.

[0041] In the context of IEEE 802.11 (Wi-Fi) technologies, a station, which is interchangeably referred to as a STA, is a communication apparatus that has the capability to use the IEEE 802.11 protocol. Based on the IEEE 802.11-2016 definition, a STA can be any device that contains an IEEE 802.11-conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM).

[0045]

[0042] For example, a STA may be a laptop, a desktop personal computer (PC), a personal digital assistant (PDA), an access point or a Wi-Fi phone in a wireless local area network (WLAN) environment. The STA may be fixed or mobile. In the WLAN environment, the terms “STA”, “wireless client”, “user”, “user device”, and “node” are often used interchangeably.

[0046]

[0043] Likewise, an AP, which may be interchangeably referred to as a wireless access point (WAP) in the context of IEEE 802.11 (Wi-Fi) technologies, is a communication apparatus that allows STAs in a WLAN to connect to a wired network. The AP usually connects to a router (via a wired network) as a standalone device, but it can also be integrated with or employed in the router.

[0047]

[0044] As mentioned above, a STA in a WLAN may work as an AP at a different occasion, and vice versa. This is because communication apparatuses in the context of IEEE 802.1 1 (Wi-Fi) technologies may include both STA hardware components and AP hardware components. In this manner, the communication apparatuses may switch between a STA mode and an AP mode, based on actual WLAN conditions and / or requirements.

[0048]

[0045] In a MIMO wireless network, “multiple” may refer to multiple antennas used simultaneously for transmission and multiple antennas used simultaneously for reception, over a radio channel. In this regard, “multiple-input” may refer to multiple transmitter antennas, which input a radio signal into the channel, and “multiple-output” may refer to multiple receiver antennas, which receive the radio signal from the channel and into the receiver. For example, in an N * M MIMO network system, N is the number of transmitter antennas, M is the number of receiver antennas, and N may or may not be equal to M. For the sake of simplicity, the respective numbers of transmitter antennas and receiver antennas are not discussed further in the present disclosure.

[0049]

[0046] In a MIMO wireless network, single-user (SU) communications and multi-user (MU) communications can be deployed for communications between communication apparatuses such as APs and ST As. MIMO wireless network has benefits like spatial multiplexing and spatial diversity, which enable higher data rates and robustness through the use of multiple spatial streams.

[0050]

[0047] In various embodiments below, each of the terms such as “channel” and “subchannel” may be used interchangeably with any one of “band”, “subband” “frequency” and “frequency resource”. The term “circuitry” may be used interchangeably with “module”.

[0051]

[0048] In various embodiments below, the term “sharing AP" refers to an AP that shares resources with another AP (e.g., shared AP) as part of multi-AP (M-AP) coordination and / or initiates a multi-AP coordination procedure; whereas the term “shared AP” refers to an AP that be shared resources by another AP (e.g., sharing AP) as part of multi-AP coordination and / or participates in a multi-AP coordination procedure.

[0052]

[0049] In various embodiments below, the terms “multi-AP coordination scheme” and “multi-AP coordination procedure” may be used interchangeably. Unless explicitly indicated otherwise, it will be appreciated that, the disclosure should be applicable to various generations of IEEE 802.11 protocols and other standards and / or technologies in wireless communication involving similar features.

[0053]

[0050] As mentioned earlier, among the many discussed M-AP coordination schemes, C- TDMA mainly considers a sharing AP (an AP that share resources with another AP as part of M-AP coordination) allocating a time resource to a shared AP (an AP that be shared resources by a sharing AP as part of M-AP coordination) and the sharing AP transmitting / receiving data in the allocated time resource using the resource’s bandwidth. C-OFDMA mainly considers a sharing AP allocating a frequency resource to a shared AP and the sharing AP transmitting / receiving data in the allocated time resource using the resource’s bandwidth. Among the discussions about C-TDMA and C-OFDMA, allocation of TXOP in C-TDMA using multi-user request-to-send (MU-RTS) transmission opportunity (TXOP) sharing (TXS) trigger frame has been discussed.

[0054]

[0051] Figure 1 shows a schematic diagram illustrating a transmission opportunity (TXOP) sharing (TXS) procedure 100 in C-TDMA involving a sharing access point (AP) 102 and a single shared AP 104. For example, the sharing AP 102 uses a multi-user request-to-send (MU-RTS) TXS trigger frame 1 10 to allocate time within a TXOP 108 to the shared AP 104, initiating the TXS procedure. Upon receiving the MU-RTS TXS trigger frame 110 from the sharing AP 102, the shared AP 104 transmits a clear-to-send (CTS) frame 112 to the sharing AP 102, and performs frame exchange 114 during time allocated by the MU-RTS TXS trigger frame 116 (e.g., allowing the shared AP 104 to perform data transmission to its non-AP STA 106 in its BSS).

[0055]

[0052] Figure 2 shows a schematic diagram illustrating a TXOP sharing procedure 200 in C- TDMA involving a sharing AP 202 and multiple shared APs 204, 206. For example, the sharing AP 202 uses MU-RTS TXS trigger frames 210, 218 to allocate times within a TXOP 208 to the shared AP 206 and the shared AP 204 respectively, initiating the TXS procedure. Upon receiving the MU-RTS TXS trigger frames 210, 218 from the sharing AP 202, shared APs 206, 204 respectively transmits a CTS frame 212, 220 to the sharing AP 202, enabling frame exchange 214, 222 during their respective allocated times 216, 224 (Allocated Time_1 , Allocated Time_2).

[0056]

[0053] Figure 3 shows a schematic diagram illustrating a communication apparatus 300 according to various embodiments of the present disclosure. The communication apparatus 300 may be implemented as an AP or a STA.

[0057]

[0054] As shown in Figure 3, the communication apparatus 300 may include circuitry 314, at least one radio transmitter 302, at least one radio receiver 304, and at least one antenna 312 (for the sake of simplicity, only one antenna is depicted in Figure 3 for illustration purposes). The circuitry 314 may include at least one controller 306 for use in software and / or hardware aided execution of tasks that the at least one controller 306 is designed to perform, including but not limited to control of communications with one or more other communication apparatuses in a MIMO wireless network. The circuitry 314 may further include at least one transmission signal generator 308 and at least one receive signal processor 310. The at least one controller 306 may control the at least one transmission signal generator 308 for generating physical layer protocol data units (PPDUs) to be sent through the at least one radio transmitter 302 to one or more other communication apparatuses. Here, the PPDU, for example, may be PPDUs used for downlink transmissions if the communication apparatus 300 is an AP. Alternatively, the PPDU may be PPDUs used for trigger-based uplink transmissions if the communication apparatus 300 is a STA. The at least one controller 306 may control the at least one receive signal processor 310 for processing MAC frames and PPDUs received through the at least one radio receiver 304 from the one or more other communication apparatuses under the control of the at least one controller 306. Here the PPDU, for example, may be PPDUs used for trigger-based uplink transmissions if the communication apparatus 300 is an AP. Alternatively, the PPDU may be PPDUs used for downlink transmissions if the communication apparatus 300 is a STA. The at least one transmission signal generator 308 and the at least one receive signal processor 310 may be stand-alone modules of the communication apparatus 300 that communicate with the at least one controller 306 for the above-mentioned functions, as shown in Figure 3. Alternatively, the at least one transmission signal generator 308 and the at least one receive signal processor 310 may be included in the at least one controller 306. It is appreciable to those skilled in the art that the arrangement of these functional modules is flexible and may vary depending on the practical needs and / or requirements. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and / or in chipsets. In various embodiments, when in operation, the at least one radio transmitter 302, at least one radio receiver 304, and at least one antenna 312 may be controlled by the at least one controller 306.

[0058]

[0055] The communication apparatus 300, which in operation, may provide functions required forM-AP coordination. For example, the communication apparatus 300 may be a shared AP which is shared resources by another AP (e.g., sharing AP) as part of multi- AP coordination, and the circuitry 314 (for example the at least one transmission signal generator 308 of the circuitry 314) may be configured to generate a first frame (e.g., a Required TXOP Report (RTR) frame) within a time period obtained by or allocated to the shared AP, the first frame comprising a first signal field indicating a time or frequency resource required for the shared AP to exchange data in a basic service set (BSS) of the shared AP. The at least one radio transmitter 302 may transmit the first frame to another AP (e.g., a sharing AP).

[0059]

[0056] In an embodiment, the circuitry 314 (for example the at least one controller 306 of the circuitry 314) may determine whether the time period is sufficient, e.g., for a data exchange in the BSS of the shared AP, and the at least one radio transmitter 302 may transmit the first frame to the another AP within the time period in response to determining that the time period is sufficient. Alternatively, the at least one radio transmitter 302 may broadcast the first frame in response to determining that the time period is not sufficient.

[0060]

[0057] In another embodiment, the at least one radio receiver 304 may receive a second frame (e.g., MU RTS-TXS trigger frame) comprising a second signal field allocating the time or frequency resource to be used by the shared AP for exchanging the data in the BSS of the shared AP.

[0058] In one embodiment, where the time period is a first TXOP obtained by the shared AP, the at least one radio receiver 304 may receive a third frame (e.g., Required TXOP Report Poll (RTRP) frame) within a second TXOP of the another AP prior to the first TXOP, the third frame comprising a third signal field carrying an indication to solicit the first frame. In an alternative embodiment, the at least one radio receiver 304 may receive a third frame (e.g., Required TXOP Report Poll (RTRP) frame) from the another AP prior to the time period, the third frame comprising a third signal field carrying an indication to solicit the first frame and a fourth signal field allocating the time period to the shared AP to exchange frames in the BSS of the shared AP within the time period.

[0061]

[0059] In various embodiments below, within the time period and prior to generating the first frame, the at least one radio transmitter 302 may transmit a fourth frame to a station in the BSS of the shared AP and the at least one radio receiver 304 may receive a fifth frame comprising information relating to the station, and the circuitry 314 (for example the at least one transmission signal generator 308 of the circuitry 314) may be configured to generate the first frame based on the information relating to the station.

[0062]

[0060] The communication apparatus 300 may be a sharing AP which shares resources with another AP (e.g., shared AP) as part of multi-AP coordination, and the at least one radio receiver 304 may receive a first frame (e.g., RTR frame) from an AP (e.g., a shared AP) of one or more other APs (e.g., shared APs). The circuitry 314 (for example the receive signal processor 310 of the circuitry 314) may process the first frame. The at least one transmitter 302 may transmit a second frame (e.g., MU RTS-TXS trigger frame) to the shared AP, the second frame allocating the time or frequency resource to be used by the shared AP for exchanging the data in the BSS of the shared AP.

[0063]

[0061] The circuitry 314 (for example the at least one transmission signal generator 308 of the circuitry 314) may generate a third frame (e.g., RTRP frame) comprising a third signal field soliciting the first frame from the shared AP; and the at least one transmitter 302 may transmit the third frame to the shared AP prior to the time period. Optionally, the third frame may comprise a fourth signal field allocating the time period to the shared AP to exchange frames in the BSS of the shared AP within the time period.

[0064]

[0062] Figure 4 shows a flowchart 400 illustrating a method for M-AP coordination according to various embodiments of the present disclosure. In step 402, a step of generating a first frame within a time period is carried out. The first frame may comprise a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of a first AP. In step 404, a step of transmitting the first frame to a second AP is carried out.

[0065]

[0063] Figure 5 shows a flowchart 500 illustrating a method for M-AP coordination according to various embodiments of the present disclosure. In step 502, a step of receiving a first frame from a first AP of one or more first APs within a time period obtained by or allocated to the first AP is carried out. The first frame comprises a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP. In step 504, a step of processing the first frame is carried out. In step 506, a step of transmitting a second frame to the first AP is carried out, where the second frame allocates the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0066]

[0064] Figure 6 shows a schematic diagram 600 illustrating communications between two APs 602, 604 for M-AP coordination according to various embodiments of the present disclosure. A first AP (AP1 ) 604 may send a resource report 606 (e.g., comprising information or a request relating to resources) to a second AP (AP2) 602 that supports multi-AP coordination prior to the multi-AP coordination procedure (scheme) 608. Advantageously, the AP can allocate resources accurately based on information in the resource report.

[0067]

[0065] In the following paragraphs, a first embodiment of the present disclosure, where a resource report poll is transmitted by the second AP prior to the transmission of the resource report by the first AP for C-TDMA uplink information gathering, is described.

[0068]

[0066] Figure 7 shows a schematic diagram illustrating a TXOP sharing procedure 700 involving a sharing AP (AP2) 702 and a shared AP (AP1) 704 for M-AP coordination according to the first embodiment of the present disclosure. Prior to multi-AP coordination scheme between a first AP (AP1 ) 704 and a second AP (AP2) 702, AP2 702 may firstly send a resource report poll 706 to AP1 704 for soliciting a resource report. AP1 704 receiving the frame may subsequently send the resource report 708 (e.g., comprising information and / or request relating to resources) to AP2 702. Advantageously, a resource report frame is solicited from a non-TXOP holder AP such as AP1 704 to help in resource allocation.

[0069]

[0067] Figure 8 shows a schematic diagram illustrating a TXOP sharing procedure 800 involving a sharing AP (AP2) 802, a shared AP (AP1 ) 804 and a non-AP STA 806 in the shared AP’s BSS for M-AP coordination according to a first variant of the first embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 806 in the shared AP’s BSS (API’s BSS) is illustrated. It is appreciated there may be more than one non-AP STA in the shared AP’s BSS. The sharing AP (AP2) 802 may transmit a trigger frame (e.g., Required Transmission Opportunity (TXOP) Report Poll (RTRP)) 812 to the shared AP (AP1 ) 804 to allocate a portion of the TXOP (e.g., time 813) for the shared AP to perform intra-BSS information gathering (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., a resource report or RTR frame) 820.

[0070]

[0068] After receiving the trigger frame 812, the shared AP 804 (AP1) may process the frame 812 to perform a Clear-To-Send (CTS) procedure (e.g., transmitting a CTS frame 814 to the sharing AP 802 (AP2)). Then the shared AP 804 may perform information gathering 815 in its BSS, for example by initiating Buffer Status Report Poll (BSRP) - Buffer Status Report (BSR) exchanges with one or more associated STAs using the allocated resources (e.g., an amount of time resource). For example, the shared AP 804 transmits a BSRP frame 816 to associated non-AP STA(s) (e.g., non-AP STA 806) to solicit a BSR frame(s) 818 to collect buffer status of the STA(s). Alternatively, the shared AP 804 may skip information gathering. For example, the shared AP may skip information gathering when the shared AP 804 does not intend to perform uplink communication with the associated STAs during an upcoming TXOP sharing (e.g., TXS phase) or the shared AP 804 may have information about the uplink traffic for the associated STAs already.

[0071]

[0069] During the remaining time of the time 813 allocated to AP1 804 after the intra-BSS information gathering 815, the shared AP 804 transmits a frame (e.g., RTR frame) 820 to sharing AP 802. The RTR frame 820 may comprise information (e.g., required TXOP duration and low latency (LL) requirements information) useful for the allocating of time resource by the sharing AP 802 to the shared AP 804. The shared AP 804 may determine such information, e.g., based on the buffer status of the shared AP 804 and / or the information obtained during the information gathering 815. It should be noted that the frame 820 may also function as a TXOP return, where AP1 804 returns the allocated time / resource 813 back to AP2 802.

[0072]

[0070] After receiving the RTR frame 820, during upcoming TXOP sharing (e.g., TXS phase 821), the sharing AP 802 may perform TXOP sharing with the shared AP 804 (e.g., C-TDMA, C-OFDMA, triggered TXOP sharing with AP, etc.). For example, the sharing AP 802 may generate a frame (e.g., multi-user request-to-send (MU-RTS) TXS trigger frame) 822 for allocating a TXOP obtained by the sharing AP 802, the frame 822 allocating a portion of the TXOP 823 for the shared AP 804 to perform data transmission 826 in a BSS of the shared AP 804 (e.g., the data may be transmitted to one or more communication apparatuses in the BSS of the shared AP 804, such as a STA, another AP, or other similar communication apparatus). The sharing AP 802 may determine the duration of the allocation 823 based on the information or request (e.g., required TXOP duration and LL requirements information) in the RTR frame 820 sent by the shared AP 804. The sharing AP 802 may then transmit the frame 822 to the shared AP 804. After receiving the frame 822, the shared AP 804 may process the frame 822 to perform a CTS procedure (e.g., transmitting a CTS frame 824 to the sharing AP 82) and then performs data transmission 826 in its BSS during its allocated time 823. Advantageously, in this variant, the sharing AP allocates resources for the shared AP to gather intra-BSS information before sending the report for more accurate information.

[0073]

[0071] Figure 9 shows a schematic diagram illustrating another TXOP sharing procedure 900 involving a sharing AP (AP2) 902, a shared AP (AP1) 904 and a non-AP STA 906 in the shared AP’s BSS without intra-BSS information gathering according to the first variant of the first embodiment of the present disclosure. For the sake of simplicity, only one non- AP STA 906 in the shared AP’s BSS is illustrated. It is appreciated there may be more than one non-AP STA in the shared AP’s BSS. The sharing AP (AP2) 902 may transmit a trigger frame (e.g., Required Transmission Opportunity (TXOP) Report Poll (RTRP)) 912 to the shared AP (AP1) 904 to solicit transmission of another frame (e.g., a resource report or RTR frame) 916.

[0074]

[0072] After receiving the trigger frame 912, the shared AP 904 may process the frame 912 to perform a CTS procedure (e.g., transmitting a CTS frame 914 to the sharing AP 902). In this case, the shared AP 804 does not need to perform uplink communication with the associated ST As during upcoming TXOP sharing (e.g., TXS phase) or the shared AP 804 may have information about the uplink traffics at the associated STAs already therefore the shared AP 804 skip information gathering.

[0075]

[0073] The shared AP 904 then transmits a frame (e.g., RTR frame) 920 to sharing AP 902. The RTR frame 920 may comprise information (e.g., required TXOP duration and LL requirements information) useful for the allocating of time resource by the sharing AP 902 to the shared AP 904. The shared AP 904 may determine such information, e.g., based on the buffer status of the shared AP 904 and / or the information obtained before.

[0074] After receiving the RTR frame 920, during upcoming TXOP sharing (e.g., TXS phase 921), the sharing AP 902 may perform TXOP sharing with the shared AP 904 (e.g., C-TDMA, C-OFDMA, triggered TXOP sharing with AP, etc.). For example, the sharing AP 902 may generate a frame (e.g., MU-RTS TXS trigger frame) 922 for allocating a TXOP obtained by the sharing AP 902, the frame 922 allocating a portion of the TXOP 923 for the shared AP 904 to perform data transmission 926 in a BSS of the shared AP 904 (e.g., the data may be transmitted to one or more communication apparatuses in the BSS of the shared AP 904, such as a STA, another AP, or other similar communication apparatus). The sharing AP 902 may determine the duration of the allocation based on the information or request (e.g., required TXOP duration and LL requirements information) in the RTR frame 920 sent by the shared AP 904. The sharing AP 902 may then transmit the frame 922 to the shared AP 904. After receiving the frame 922, the shared AP 904 may process the frame 922 to perform a CTS procedure (e.g., transmitting a CTS frame 924 to the sharing AP 902) and then performs data transmission 926 in its BSS during its allocated time 923.

[0076]

[0075] Figures 10 and 1 1 respectively show an example format of a Common Information field and a User Information List field of an RTRP frame 1000, 1100 according to an embodiment of the present disclosure. The RTRP frame 1000, 1100 may be an MU-RTS TXS trigger frame, and may comprise a Frame Control field, a Duration field, a Recipient Address (RA) field, a Transmitter Address (TA) field, a Common Information field, a User Information List field, a Padding field and a frame check sequence (FCS) field. As shown in Figure 10, the Common Information field further comprises a Trigger Type subfield, a Reserved subfield, a More TF subfield, a CS Required subfield, an uplink (UL) Bandwidth (BW) subfield, a Guard Interval (Gl) And High Efficiency / Extremely High Throughput Long Training Field (HE / EHT-LTF) Type / Triggered TXOP Sharing (TXS) Mode subfield, an RTRP Flag subfield and another Reserved subfield. The RTRP Flag subfield indicates whether this MU-RTS TXS trigger frame is used to solicit the RTR. For example, the RTRP Flag subfield may be set to 1 to indicate this is to solicit RTR, 0 to indicate otherwise. This subfield was previously a Reserved field. Table 1 shows different TXS procedures initiated by the frame 100 having different TXS Mode subfield values. The TXS Mode subfield, may be set to 3, which was previously Reserved, to indicate an MU-RTS that initiates TXS procedure wherein a scheduled AP can transmit MPDU(s) addressed to its associated STAs or another APs. Alternatively (not shown in Table 2), the TXS Mode subfield may be set to 2 and description modified to indicate an MU-RTS that initiates TXS procedure wherein a scheduled STA can transmit MPDU(s) addressed to its associated AP or addressed to another ST A, or a scheduled AP can transmit MPDU(s) addressed to its associated ST As or another APs.

[0077] [Table 1]

[0078]

[0076] As shown in Figure 11 , the User Information List field comprises an Associated Identifier (AID12) subfield indicating an AID that uniquely identifies an AP among multiple APs, an RU Allocation subfield, an Allocation Duration subfield, a Reserved subfield and a PS160 subfield.

[0079]

[0077] Figure 12 shows an example format of an RTR frame 1200 according to an embodiment of the present disclosure. The RTR frame 1200 comprises a Frame Control field, a Duration field, three Address fields (Address 1 , Address 2, Address 3), a Sequence Control field, another Address field (Address 4), a Quality of Service (QoS) field, a HT Control field, a Frame Body and an FCS field. If RTR frame is broadcasted, the RA (Address 1 field) is set to broadcast address. The HT Control field may comprise different subfields depending on which PPDU type the frame is in. If the RTR frame 1200 is in a High Throughput (HT) PPDU, BO or bit number 0 is set to 0; B1 -B29 (bit number 1 to bit number 29) comprise a HT Control Middle subfield; B30 is set to indicate an AC Constraint, and B31 comprises RDG / More PPDU subfield. If the RTR frame 1200 is in a Very High Throughput (VHT) PPDU, BO is set to 1 , B1 is set to 0, B2 to B29 comprise a VHT Control Middle field, B30 is set to indicate an AC Constraint and B31 comprises RDG / More PPDU subfield. If the RTR frame is in a High Efficiency (HE) PPDU, BO is set to 1 , B1 is set to 1 and B2 to B31 comprise a A- Control subfield. The A-Control subfield comprises a Control List subfield and a Padding subfield, and the Control List subfield comprises a Control ID subfield and a Control Information subfield.

[0080]

[0078] The Control ID subfield indicates the type of information carried in the Control Information subfield. Table 2 shows the type of information carried in the Control Information subfield indicated by the Control ID subfield values and the respective lengths (number of bits) of the Control Information subfield. According to the present disclosure, the Control ID with value, e.g., 10, which was Reserved, is changed to indicate Required TXOP report (RTR).

[0081]

[0082] [Table 2]

[0083]

[0079] The Control Information subfield in a Control List subfield may contain information such as required TXOP duration and LL requirements information for C-TDMA TXOP sharing. Figure 13 shows an example format of a Control Information subfield 1300 in a Control List subfield of a HT Control field of an RTR frame according to an embodiment of the present disclosure. The RTR frame comprises a BW subfield having 3 bits, a Required TXOP Duration subfield with 9 bits, a Low Latency (LL) Requirements Info subfield with 5 bits and a Reserved subfield with 9 bits containing other information. The LL Requirement Info subfield comprises an LL Presence subfield with 1 bit, and an ACI Bitmap subfield with 4 bits. The BW subfield is optionally present and indicates the bandwidth for which the medium resource is requested (e.g., may only be used for calculation of allocation time). Table 3 shows an example encoding of the BW subfield. It should be noted that if the BW subfield is not present, a predefined bandwidth may be used to calculate the required TXOP.

[0084] [Table 3]

[0085]

[0080] The Required TXOP Duration subfield indicates the duration of each shared AP’s required allocated time, based on the bandwidth specified in the BW subfield. If TXOP is not required, the duration is set to 0. The LL Presence subfield may be set to 1 if LL data arrives at the shared AP and may be set to 0 to indicate otherwise. The ACI Bitmap subfield indicates the priority level of the traffic. For example, a sharing AP shares a TXOP to the AP with more urgent LL data first. Other information such as number of STAS in the BSS can be included optionally in the Reserved subfield.

[0086]

[0081] Figure 14 shows an example format of an MU-RTS TXS trigger frame 1400 according to an embodiment of the present disclosure. The MU-RTS TXS trigger frame may comprise a Frame Control field, a Duration field, a RA field, a TA field, a Common Information field, a User Information List field, a Padding field and a frame check sequence (FCS) field. The User Information List field comprises an Associated Identifier (AID12) subfield indicating an AID that uniquely identify an AP among multiple APs, an RU Allocation subfield, an Allocation Duration subfield, a Reserved subfield and a PS160 (Primary, Secondary 160 MHz Channel) subfield. The Common Information field may comprise a Trigger TXOP Sharing Mode subfield. Table 4 shows different triggered TXOP sharing modes encoded by different Triggered TXOP Sharing Mode subfield values. The Triggered TXOP Sharing Mode subfield, may be set to 3, which was previously a Reserved value, to indicate an MU-RTS that initiates TXS procedure wherein a scheduled AP can transmit MPDU(s) addressed to its associated STAs or another APs. Alternatively (not shown in Table 4), The Triggered TXOP Sharing Mode subfield may be set to 2 and description modified to indicate an MU-RTS that initiates TXS procedure wherein a scheduled STA can transmit MPDU(s) addressed to its associated AP or addressed to another STA, or a scheduled AP can transmit MPDU(s) addressed to its associated STAs or another APs.

[0087] [Table 4]

[0088]

[0082] Figure 15 shows a schematic diagram illustrating a TXOP sharing procedure 1500 using an Enhanced Distributed Channel Access (EDCA) method involving a second AP (AP2) 1502, a first AP (AP1 ) 1504, and a non-AP STA 1506 in the first AP’s BSS according to a second variant of the first embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 1506 in the first AP’s BSS is illustrated. It is appreciated there may be more than one non-AP STA in the first AP’s BSS.

[0089]

[0083] In a TXS phase 1521 , the second AP (AP2) 1502 is the sharing AP and the first AP (AP1 ) 1504 is the shared AP. The sharing AP 1502 may share a TXOP according to the information or request in an RTR frame 1522 sent by the shared AP 1504. For example, in the TXS phase 1521 , the sharing AP 1502 may perform backoff 1526 to obtain TXOP 1525 and generate a frame (e.g., MU-RTS TXS trigger frame) 1524 for allocating the time 1525 obtained by the sharing AP 1502, the frame 1524 allocating a portion of the TXOP (e.g., time 1527) for the shared AP 1504 to perform data transmission 1528 in a BSS of the shared AP 1504 (e.g., the data 1528 may be transmitted to one or more communication apparatuses in the BSS of the shared AP 1504, such as a STA, another AP, or other similar communication apparatus). The sharing AP 1502 may then transmit the frame 1524 to the shared AP, to allocate the portion of the TXOP based on information (e.g., required TXOP duration and LL requirements information) received from the shared AP 1504. After receiving the frame 1522, the shared AP 1504 may process the frame 1522 to perform a CTS procedure (e.g., transmitting a CTS frame 1526 to the sharing AP 1502) and then perform data transmission 1528 in its BSS during its allocated time 1527.

[0090]

[0084] Before the TXS phase 1521 , where prior to the generation of the frame (e.g., MORTS TXS trigger frame) 1524, during the second AP’s TXOP 151 1 , the second AP 1502 may transmit a management frame (e.g., RTRP frame) 1512 to the first AP 1504 to trigger the first AP 1504 to, e.g., optionally, perform intra-BSS information gathering 1519 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 1520. After receiving the management frame (e.g., RTRP frame) 1512, the first AP 1504 may process the frame 1512 to perform an ACK procedure (e.g., transmitting an ACK frame 1514 to the second AP) and then perform backoff 1516 to obtain TXOP 1517. For example, a backoff value (e.g., a value of 1 ) may be randomly selected and counted down when obtaining the TXOP 1517. After obtaining TXOP 1517, the first AP 1504 transmits a trigger frame (e.g., BSRP frame) 1518 to associated non-AP STA 1506 to solicit another frame (e.g., BSR frame) 1520 for intra-BSS information gathering 1519. During the remaining time of the first AP’s TXOP 1517 obtained by AP1 1504 after the intra-BSS information gathering 1519, the first AP 1504 transmits another frame (e.g., RTR frame) 1522 to second AP 1502. The RTR frame 1522 may comprise the information (e.g., required TXOP duration and LL requirements information) useful for allocating the time resource by the second AP 1502 to the first AP 1504. Advantageously, in this variant, the first AP can obtain the TXOP at a suitable to perform intra-BSS information gathering and RTR transmission.

[0091]

[0085] Figure 16 shows an example format of an element in an RTRP frame 1600 according to an embodiment of the present disclosure. A new element is defined and is included in a Beacon frame to be the RTRP frame. The RTRP frame 1600 comprises an Element ID field, a Length field, an Element ID Extension field, an Info field. The Element ID field is set to, e.g., 255, and the Element ID Extension set to, e.g., 115, defined for indicating the RTRP, which was previously, a Reserved element.

[0086] Figure 17 shows a schematic diagram illustrating TXOP sharing procedures 1700 involving a sharing AP 1702 (AP2) and multiple shared APs, 1704 (AP1 ), 1708 (AP3) and multiple non-AP ST As 1706, 1710 in the shared APs’ BSSs according to a third variant of the first embodiment of the present disclosure. For the sake of simplicity, only one non- AP STA 1706, 1710 in each shared AP’s BSS is illustrated, i.e., STA 1706 is in API ’s BSS and STA 1710 is in AP3’s BSS. It is appreciated there may be more than one non-AP STA in each shared AP’s BSS.

[0092]

[0087] In a TXS phase 1731 , the sharing AP 1702 may generate a frame (e.g., MU-RTS TXS trigger frame) 1732 for allocating a TXOP obtained by the sharing AP 1702. The frame 1732 may allocate a portion of the TXOP for one of the shared AP, for example, the shared AP (AP3) 1708, to perform data transmission 1736 in a BSS of the shared AP 1708, e.g., the data 1736 may be transmitted to one or more communication apparatuses in the BSS of the shared AP 1708, such as a STA, another AP, or other similar communication apparatus. After receiving the frame 1732, the shared AP 1708 may process the frame 1732 to perform a CTS procedure (e.g., transmitting a CTS frame 1734 to the sharing AP 1702) and then performs data transmission 1736 in the BSS of AP 1708 during a time 1733 allocated to the AP3 1708e. Subsequently, the sharing AP 1702 may generate another frame (e.g., MU-RTS TXS trigger frame) 1738 for allocating TXOP to another shared AP, for example shared AP (AP1) 1704, repeating the above process including a CTS procedure (e.g., transmitting a CTS frame 1740 by the another shared AP 1704 to the sharing AP 1702), and data transmission 1742 in a BSS of the another shared AP 1704 during a time 1739 allocated to the AP1 1704.

[0093]

[0088] Before the TXS phase 1731 , which occurs prior to the generation of the frame (e.g., MU-RTS TXS trigger frame) 1732, the sharing AP 1702 may transmit multiple trigger frames (e.g., RTRP frame) 1712, 1722 to multiple shared APs to allocate portions of the TXOP (e.g., time 1715, 1725) for the shared APs 1704, 1708 to perform intra-BSS information gathering 1717, 1727 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 1720, 1730, respectively.

[0094]

[0089] For each shared AP 1704, 1708, after receiving the trigger frame (e.g., RTRP frame) 1712, 1722, the shared AP, 1704, 1708 may process the frame 1712, 1722 to perform a corresponding CTS procedure (e.g., transmitting a CTS frame 1714, 1724 to the sharing AP 1702) and then transmit a trigger frame (e.g., BSRP frame) 1716, 1726 to the associated non-AP STA 1706, 1710 to solicit another frame (e.g., BSR frame) 1718, 1728 for intra-BSS information gathering 1717, 1727, respectively.

[0095]

[0090] Subsequently, during the remaining time of the time allocated to each shared AP 1704, 1708, the shared AP 1704, 1708 may respectively transmit a frame (e.g., RTR frame) 1720, 1730 to sharing AP 1702. The RTR frames 1720, 1730 may comprise the information (e.g., required TXOP duration and LL requirements information) for allocating the times (e.g., 1733, 1739) for the shared APs 1704, 1708 to perform data transmissions 1736, 1742 during upcoming TXOP sharing. Although the same term “Time allocated to AP1” are used twice in Figure 17, it is appreciated by a skilled person that the “Time allocated to the AP1” indicated by different reference numerals 1715 and 1739 may refer to different time periods / resources allocated to the first AP 1704 and are not necessarily related to each other. As explained above, the time 1715 allocated to the first AP 1704 refers to a portion of the TXOP allocated to the first AP 1704 before the TXS phase 1731 to perform intra-BSS information gathering 1717 in the first AP’s BSS; whereas the time 1739 allocated to the first AP 1704 refers to a portion of the TXOP allocated to the first AP 1704 in the TXS phase 1731 after receiving the MU-RTS TXS trigger frame 1738 to perform data transmission 1736 in the first AP’s BSS 1708. A similar explanation applies to the term “Time allocated to AP3” indicated by different reference numerals 1725, 1733 referring to portions of TXOPs allocated to the third AP 1808 before and in the TXS phase 1731 , respectively.

[0096]

[0091] The order of allocation of the TXOP may be based on the information (e.g., LL requirements information) included in the frames (e.g., RTR frames) 1720, 1730 received from the corresponding shared APs 1704, 1708. For example, if information from shared AP3 1708 indicates arrival of data of a certain traffic type (e.g., LL data, data having higher priority, or data requiring urgent transmission), the sharing AP 1702 may share the TXOP with the shared AP3 1708 first (e.g., by sending MU-RTS TXS trigger frame 1732 to shared AP3 1708 first).

[0097]

[0092] It should be noted that the RTRP frame, RTR frame, MU-RTS TXS trigger frame illustrated in this third variant with multiple shared APs are the same as those in the first variant with a single shared AP illustrated in Figures 8 and 9.

[0098]

[0093] Figure 18 shows a schematic diagram illustrating TXOP sharing procedures 1800 using an EDCA method involving a second AP (AP2) 1802, a first AP (AP1) 1804 and a third AP (AP3) 1808 and multiple non-AP STAs 1806, 1810 in the first and third APs’ BSSs according to a fourth variant of the first embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 1806, 1810 in each of the first AP’s BSS and the third AP’s BSS is illustrated. It is appreciated there may be more than one non-AP STA in each of the first AP’s BSS and the third AP’s BSS.

[0099]

[0094] In a TXS phase 1837, the second AP (AP2) 1802 is the sharing AP and the first AP (AP1 ) 1804 and the third AP (AP3) 1808 are the shared APs. The sharing AP 1802 may generate a frame (e.g., MU-RTS TXS trigger frame) 1838 for allocating a TXOP obtained by the sharing AP 1802, the frame 1838 allocating a portion of the TXOP for one of the shared APs, for example, shared AP 1808, to perform data transmission 1842 in a BSS of the shared AP 1808 (e.g., the data 1842 may be transmitted to one or more communication apparatuses in the BSS of the shared AP 1808, such as a STA, another AP, or other similar communication apparatus). After receiving the frame 1838, the shared AP 1808 may process the frame 1838 to perform a CTS procedure (e.g., transmitting a CTS frame 1840 to the sharing AP 1802) and then performs data transmission 1842 in its BSS during its allocated time 1839. The sharing AP 1802 may generate another frame (e.g., MU-RTS TXS trigger frame) 1844 for allocating TXOP 1845 to another shared AP, for example shared AP 1804, repeating the above process including a CTS procedure (e.g., transmitting a CTS frame 1846 by the another shared AP 1804 to the sharing AP 1802), and data transmission 1848 in a BSS of the another shared AP 1848 during the AP’s allocated time 1845.

[0100]

[0095] Before the TXS phase 1837, where prior to the generation of the frame (e.g., MU- RTS TXS trigger frame) 1838, the second AP 1802 may transmit multiple management frames (e.g., RTRP frames) 1812, 1816 to the first and third APs 1804, 1808 to perform intra-BSS information gathering 1825, 1833 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 1828, 1836, respectively.

[0101]

[0096] For the first and third APs 1804, 1808, after receiving the management frame (e.g., RTRP frame) 1812, 1816, the first and third APs 1804, 1808 may process the frame 1812, 1816 to perform an ACK procedure (e.g., transmitting an ACK frame 1814, 1818 to the second AP 1802) and then perform backoff 1822, 1830 to obtain TXOP 1823, 1831 , respectively. A backoff value (e.g., a value of 4) may be randomly selected and counted down. After obtaining TXOP 1823, 1831 , the first and third APs 1804, 1808 may transmit a trigger frame (e.g., BSRP frame) 1824, 1832 to associated non-AP STA 1806, 1810 to solicit another frame (e.g., BSR frame) 1826, 1834 for intra-BSS information gathering 1825, 1833, respectively.

[0097] Subsequently, during the remaining time of the time allocated to the first and third APs 1804, 1808, the first and third APs 1804, 1808 may transmit another frame (e.g., RTR frame) 1828, 1836 to the second AP 1802. The RTR frames 1828, 1836 may comprise the information (e.g., required TXOP duration and LL requirements information) for allocating the times (e.g., 1839, 1845) for the first and third APs 1804, 1808 to perform data transmissions 1842, 1848 during upcoming TXOP sharing.

[0102]

[0098] Alternatively, the second AP 1802 may transmit a broadcast or multicast management frame (e.g., RTRP frame) to the first and third APs 1804, 1808, and after receiving the management frame (e.g., RTRP frame), the first and third APs 1804, 1808 may perform backoff to obtain a TXOP without performing the ACK procedure first. Similarly, although the same term “Time allocated to AP1” are used twice in Figure 18, it is appreciated by a skilled person that the “Time allocated to the AP1” indicated by different reference numerals 1823 and 1845 refer to different time periods / resources allocated to the first AP 1804, and are not necessarily related to each other. As explained above, the time 1823 allocated to the first AP11804 refers to a portion of the TXOP allocated to the first AP 1804 before the TXS phase 1837 to perform intra-BSS information gathering 1825 in the first AP’s BSS; whereas the time 1845 allocated to the first AP 1804 refers to a portion of the TXOP allocated to the first AP 1804 in the TXS phase 1837 after receiving the MU-RTS TXS trigger frame 1838 to perform data transmission 1848 in the first AP’s BSS. A similar explanation applies to the term “Time allocated to AP3” indicated by different reference numerals 1831,1839 referring to portions of TXOPs allocated to the third AP 1808 before and in the TXS phase 1837, respectively.

[0103]

[0099] The order of allocation of the TXOP may be based on the information (e.g., LL requirements information) included in the frames (e.g., RTR frames) received from the shared APs 1804, 1808. For example, if information from shared AP3 1808 indicates arrival of data of a certain traffic type (e.g., LL data, data having higher priority, data requiring urgent transmission), the sharing AP 1802 may share the TXOP with the shared AP3 1808 first (e.g., by sending MU-RTS TXS trigger frame 1838 to shared AP3 1808 first). It should be noted that the RTRP frame, RTR frame, MU-RTS TXS trigger frame illustrated in this fourth variant with multiple shared APs are the same as those in the second variant with a single shared AP illustrated in Figure 15.

[0104]

[0100] In the following paragraphs, a second embodiment of the present disclosure, where an AP is a TXOP holder which is holding its own TXOP, and a resource report is transmitted from the AP to another AP for C-TDMA uplink information gathering without another AP firstly transmitting an RTRP frame to solicit the resource report, is described.

[0105]

[0101] Figure 19 shows a schematic diagram illustrating a TXOP sharing procedure 1900 involving a sharing AP 1902, a shared AP 1904, and a non-AP STA 1906 in the shared AP’s BSS according to the second embodiment of the present disclosure. In the procedure, shared AP 1904 may broadcast an unsolicited RTR to the sharing AP 1902.

[0106]

[0102] In a TXS phase 1917, the sharing AP (AP2) 1902 may share a TXOP according to the information or request in an RTR frame 1916 sent by the shared AP 1904. For example, in the TXS phase 1917, the sharing AP 1902 may generate a frame (e.g., MU- RTS TXS trigger frame) 1920 for allocating a TXOP 1919 obtained by the sharing AP 1902, the frame 1920 allocating a portion of the TXOP (e.g., time 1921) for the shared AP 1904 to perform data transmission 1924 in a BSS of the shared AP 1904 (e.g., the data 1924 may be transmitted to one or more communication apparatuses in the BSS of the shared AP 1904, such as a STA, another AP, or other similar communication apparatus). The sharing AP 1902 may then transmit the frame 1920 to the shared AP 1904, to allocate the portion of the TXOP based on information (e.g., required TXOP duration and LL requirements information) received from the shared AP 1904. After receiving the frame 1920, the shared AP 1904 may process the frame 1920 to perform a CTS procedure (e.g., transmitting a CTS frame 1922 to the sharing AP 1902) and then performs data transmission 1924 in its BSS during its allocated time 1921.

[0107]

[0103] Before the TXS phase 1917, where prior to the generation of the frame (e.g., MU- RTS TXS trigger frame) 1920, the TXOP-holder AP (AP1) 1904 holding a TXOP 1911 transmits a trigger frame (e.g., BSRP frame) 1912 to associated non-AP STA 1906 to solicit another frame (e.g., BSR frame) 1914 for intra-BSS information gathering 1913 (e.g., obtaining information about uplink traffic for associated STAs) during the TXOP 1911. If the TXOP 1911 or the remaining TXOP of the TXOP holder AP’s TXOP 1911 is not sufficient, e.g., for a data exchange in the BSS of the shared AP 1904, the TXOP- holder AP 1904 broadcasts a frame (e.g., RTR frame) 1916 requesting resources (e.g., an amount of time resource) in a future TXOP. The RTR frame 1916 may comprise the information (e.g., required TXOP duration and LL requirements information) for allocating the time in the upcoming TXOP sharing. It should be noted that the RTR frame, MU-RTS TXS trigger frame illustrated in this second embodiment in Figure 19 may be the same as those in the different variants of the first embodiment in Figures 8, 9, 15, 17 and 18.

[0104] In the following paragraphs, a third embodiment of the present disclosure, where a resource report poll is transmitted by the second AP prior to the transmission of the resource report by the first AP for coordinated orthogonal frequency-division multiple access (C-OFDMA) uplink information gathering, is described.

[0108]

[0105] Figure 20 shows a schematic diagram illustrating a channel sharing procedure 2000 involving a sharing AP (AP2) 2002, a shared AP (AP1) 2004 a non-AP STA (non-AP STA2) 2006 in the sharing AP’s BSS and a non-AP STA (non-AP STA1 ) 2008 in the shared AP’s BSS for M-AP coordination according to a first variant of the third embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 2006 in the sharing AP’s BSS (AP2’s BSS) and only one non-AP STA 2008 in the shared AP’s BSS (AP1 ’s BSS) are illustrated. It is appreciated there may be more than one non-AP STA in the sharing AP’s BSS and / or shared AP’s BSS. The sharing AP (AP2) 2002 may transmit a trigger frame (e.g., RTRP 2012) to the shared AP (AP1 ) 2004 to allocate a portion of the TXOP (e.g., time 2015) for the shared AP to perform intra-BSS information gathering (e.g., obtaining information about uplink traffic for associated ST As) and transmission of another frame (e.g., a resource report or RTR frame) 2020.

[0109]

[0106] After receiving the trigger frame 2012, the shared AP 2004 (AP1 ) may process the frame 2012 to perform a CTS procedure (e.g., transmitting a CTS frame 2014 to the sharing AP 2002 (AP2)). Then the shared AP 2004 may perform information gathering 2017 in its BSS, for example by initiating BSRP - BSR exchanges with one or more associated STAs using the allocated resources (e.g., an amount of time resource). For example, the shared AP 2004 transmits a BSRP frame 2016 to associated non-AP STA(s) (e.g., non-AP STA 2008) to solicit a BSR frame(s) 2018 to collect buffer status of the STA(s). Alternatively, the shared AP 2004 may skip information gathering. For example, the shared AP may skip information gathering when the shared AP 2004 does not intend to perform uplink communication with the associated STAs during an upcoming C- OFDMA transmission or the shared AP 2004 may have information about the uplink traffic for the associated STAs already.

[0110]

[0107] During the remaining time of the time 2015 allocated to AP1 2004 after the intra- BSS information gathering 2017, the shared AP 2004 transmits a frame (e.g., RTR frame) 2020 to sharing AP 2002. The RTR frame 2020 may comprise information (e.g., required channel / bandwidth and LL requirements information) useful for the allocating frequency resource by the sharing AP 2002 to the shared AP 2004 during an upcoming C-OFDMA transmission 2021. The shared AP 2004 may determine such information, e.g., based on the buffer status of the shared AP 2004 and / or the information obtained during the information gathering 2017. It should be noted that the frame 2020 may also function as a TXOP return, where AP1 2004 returns the allocated time / resource 2015 back to AP2 2002.

[0111]

[0108] After receiving the RTR frame 2020, the sharing AP 2002 may perform C-OFDMA transmission 2021 with the shared AP 2004 using the information contained in the RTR frame 2020. For example, the sharing AP 2002 may generate a frame (e.g., M-AP trigger frame) 2022 for allocating a channel for the shared AP to perform data transmission (e.g., the data may be transmitted to from one or more communication apparatuses in the BSS of the shared AP 2004, such as a STA, another AP, or other similar communication apparatus). The sharing AP 2002 may determine the channel to be allocated based on the information or request (e.g., required TXOP duration and LL requirements information) in the RTR frame 2020 sent by the shared AP 2004. The sharing AP 2002 may then transmit the frame 2022 to the shared AP 2004 for allocating the channel for the shared AP 2004. After receiving the frame 2022, the shared AP 2004 may transmit a trigger frame 2026 to the non-AP STA 2008 in the shared AP’s BSS on the allocated channel while the sharing AP 2002 may transmit a trigger frame 2024 to the non-AP STA 2006 in the sharing AP’s BSS on another channel. The non-AP STA 2008 in the shared AP’s BSS and the non-AP STA 2006 in the sharing AP’s BSS may perform uplink communications (e.g., by transmitting UL PPDUs 2030, 2028) with the shared AP 2004 and the sharing AP 2002 on the allocated channel and another channel, respectively. After the shared AP 2004 and the sharing AP 2002 receive the UL PPDUs 2028, 2030, they may transmit acknowledgement frames 2032, 2034 back to their respective non-AP STAs 2006, 2008 in the BSSs on the respective channels.

[0112]

[0109] Figure 21 shows a schematic diagram illustrating a channel sharing procedure 2100 using an EDCA method involving a second AP (AP2) 2102, a first AP (AP1 ) 2104, a non-AP STA 2106 in the second AP’s BSS and a non-AP STA 2108 in the first AP’s BSS according to a second variant of the third embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 2106 in the second AP’s BSS and only one non- AP STA 2108 in the first AP’s BSS are illustrated. It is appreciated there may be more than one non-AP STA in the second AP’s BSS and / or first AP’s BSS.

[0113]

[0110] During the second AP’s TXOP 2111 , the second AP 2102 may transmit a management frame (e.g., RTRP frame) 2112 to the first AP 2104 to trigger the first AP 2104 to, e.g., optionally, perform intra-BSS information gathering 21 17 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 2122. After receiving the management frame (e.g., RTRP frame) 2112, the first AP 2104 may process the frame 21 12 to perform an ACK procedure (e.g., transmitting an ACK frame 2114 to the second AP) and then perform backoff 2116 to obtain TXOP 21 15. For example, a backoff value (e.g., a value of 1) may be randomly selected and counted down when obtaining the TXOP 2115. After obtaining TXOP 2115, the first AP 1504 transmits a trigger frame (e.g., BSRP frame) 2118 to its associated non-AP STA 2108 to solicit another frame (e.g., BSR frame) 2120 for intra-BSS information gathering 2117. During the remaining time of the first AP’s TXOP 21 15 obtained by AP1 2104 after the intra-BSS information gathering 21 17, the first AP 2104 transmits another frame (e.g., RTR frame) 2122 to second AP 2102. The RTR frame 2112 may comprise the information (e.g., required channel / bandwidth and LL requirements information) useful for allocating frequency resource (channel) by the second AP 2102 to the first AP 2104.

[0114]

[0111] During a subsequent second AP’s TXOP 2125, the second AP (AP2) 2102 is the sharing AP and the first AP (AP1 ) 2104 is the shared AP. The sharing AP 2102 may perform C-OFDMA transmission 2127 according to the information or request in the RTR frame 2122 sent by the shared AP 2104. For example, the sharing AP 2102 may perform backoff 2124 to obtain TXOP 2125 and generate a frame (e.g., M-AP trigger frame) 2126 for allocating the channel for the shared AP 2104. After receiving the frame 2126, the shared AP 2104 may transmit a trigger frame 2130 to the non-AP STA 2108 in the shared AP’s BSS on the allocated channel while the sharing AP 2102 may transmit a trigger frame 2128 to the non-AP STA 2106 in the sharing AP’s BSS on another channel. The non-AP STA 2106 in the shared AP’s BSS and the non-AP STA 2110 in the sharing AP’s BSS may perform uplink communications (e.g., by transmitting UL PPDUs 2132, 2134) with the shared AP 2104 and the sharing AP 2102 on the allocated channel and another channel, respectively. After the shared AP 2104 and the sharing AP 2102 receive the UL PPDUs 2132, 2134, they may transmit acknowledgement frames 2136, 2138 back to their respective non-AP STAs 2106, 2108 in the BSSs on the respective channels.

[0115]

[0112] Figure 22 shows a schematic diagram illustrating channel sharing procedures 2220 involving a sharing AP 2202 (AP2) and multiple shared APs 2204 (AP1), 2208 (AP3) and multiple non-AP STAs 2206, 2210 in the shared APs’ BSSs according to a third variant of the third embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA2206, 2210 in each shared AP’s BSS is illustrated. It is appreciated there may be more than one non-AP STA in each shared AP’s BSS.

[0116]

[0113] The sharing AP 2202 may transmit multiple trigger frames (e.g., RTRP frame) 2212, 2222 to multiple shared APs 2204, 2208 to allocate portions of the TXOP (e.g., time 2215, 2225 for the shared APs 2204, 2208 to perform intra-BSS information gathering 2217, 2227 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 2220, 2230, respectively.

[0117]

[0114] For each shared AP 2204, 2208, after receiving the trigger frame (e.g., RTRP frame) 2212, 2222, the shared AP, 2204, 2208 may process the frame 2212, 2222 to perform a corresponding CTS procedure (e.g., transmitting a CTS frame 2214, 2224 to the sharing AP 2202) and then transmit a trigger frame (e.g., BSRP frame) 2216, 2226 to the associated non-AP STA 2206, 2210 to solicit another frame (e.g., BSR frame) 2218, 2228 for intra-BSS information gathering 2217, 2227, respectively.

[0118]

[0115] Subsequently, during the remaining time of the time allocated to each shared AP 2204, 2208, the shared AP 2204, 2208 may respectively transmit a frame (e.g., RTR frame) 2220, 2230 to sharing AP 2202. The RTR frames 2220, 2230 may comprise the information (e.g., required channel / bandwidth and LL requirements information) useful for allocating the frequency resources (channels) by the sharing AP 2202 to the shared AP 2204 during an upcoming C-OFDMA transmission 2231.

[0119]

[0116] After receiving the RTR frames 2220, 2230, the sharing AP 2202 may perform C- OFDMA transmission 2231 with the shared APs 2204, 2208 using the information contained in the RTR frames 2220, 2230. For example, the sharing AP 2202 may generate a frame (e.g., M-AP trigger frame) 2232 for allocating different channels for different shared APs 2204, 2208 to perform data transmissions in their own BSSs using the allocated channels (e.g., the data may be transmitted to from one or more communication apparatuses such as a STA, another AP, or other similar communication apparatus in the BSS of the shared AP 2204 and the BSS of the shared AP 2208, respectively). The sharing AP 2202 may determine the channels to be allocated based on the information or request (e.g., required channel / bandwidth and LL requirements information) in the RTR frames 2220, 2230 sent by the shared APs 2204, 2208. The sharing AP 2202 may then transmit a frame (e.g., M-AP trigger frame) 2232 to the shared APs 2204, 2208 for allocating the channels for the shared APs 2204, 2208. After receiving the frame 2232, each shared AP 2204, 2208 may, respectively, transmit a trigger frame 2234, 2238 to the non-AP STA 2206, 2210 in the shared AP’s BSS on the allocated channel. The non-AP STA 2206, 2210 in the BSSs of the shared APs 2204, 2208 may perform uplink communications (e.g., by transmitting UL PPDUs 2238, 2240) with the shared APs 2204, 2208 on the allocated channels, respectively. After the shared APs 2204, 2208 receive the UL PPDUs 2238, 2240 from their respective non-AP STAs 2206, 2210, they may transmit acknowledgement frames 2242, 2244 back to their respective non-AP STAs 2206, 2208 in the BSSs on the respective allocated channels.

[0120]

[0117] It should be noted that the RTRP frame and RTR frame illustrated in this third variant of the third embodiment with multiple shared APs are the same as those in the first variant of the first or third embodiment with a single shared AP illustrated in Figures 8, 9 and 20, or the third variant of the first embodiment with multiple shared APs illustrated in Figure 17.

[0121]

[0118] Figure 23 shows a schematic diagram illustrating channel sharing procedures 2300 using an EDCA method involving a second AP (AP2) 2302 a first AP (AP1) 2304 and a third AP (AP3) 2308 and multiple non-AP STAs 2306, 2310 in the first and third APs’ BSSs according to a fourth variant of the third embodiment of the present disclosure. For the sake of simplicity, only one non-AP STA 2306, 2310 in each of the first AP’s BSS and the third AP’s BSS is illustrated. It is appreciated there may be more than one non- AP STA in each of the first AP’s BSS and the third BSS.

[0122]

[0119] The second AP 2302 may transmit multiple management frames (e.g., RTRP frames) 2312 to the first and third APs 2304, 2308 to perform intra-BSS information gathering 2319, 2329 (e.g., obtaining information about uplink traffic for associated STAs) and transmission of another frame (e.g., RTR frame) 2326, 2334, respectively.

[0123]

[0120] For the first and the third APs 2304, 2308, after receiving the management frame (e.g., RTRP frame) 2312, the first and the third AP 2304, 2308 may process the frame 2312 to perform an ACK procedure (e.g., transmitting an ACK frame 2314, 2316 to the second AP 2302) and then perform backoff 2318, 2328 to obtain TXOP 2323, 2331 , respectively. A backoff value (e.g., a value of 4) may be randomly selected and counted down. After obtaining TXOP, the first and third APs 2304, 2308 may transmit a trigger frame (e.g., BSRP frame) 2322, 2330 to associated non-AP STA 2306, 2310 to solicit another frame (e.g., BSR frame) 2324, 2332 for intra-BSS information gathering 2319, 2329, respectively.

[0121] Subsequently, during the remaining time of the time 2323, 2331 allocated to the first and third APs 2304, 2308, the first and third APs 2304, 2308 may transmit another frame (e.g., RTR frame) 2326, 2334 to second AP 2302, respectively. The RTR frames 2326, 2334 may comprise the information (e.g., required channel / bandwidth and LL requirements information) for allocating the frequency resources for the first and third APs 2304, 2308 to perform data transmissions during upcoming C-OFDMA transmissions 2335.

[0124]

[0122] Alternatively, the second AP 2302 may transmit a broadcast or multicast management frame (e.g., RTRP frame) to the first and third APs, and after receiving the management frame (e.g., RTRP frame), the first and third APs may perform backoff to obtain a TXOP without performing the ACK procedure first.

[0125]

[0123] After receiving the RTR frames 2326, 2334, the second AP 2302 may perform C- OFDMA transmission 2335 with the first and third APs 2304, 2308 using the information contained in the RTR frames 2326, 2334. The second AP (AP2) 2302 is the sharing AP and the first AP (AP1 ) 2304 and the third AP (AP3) 2308 are the shared APs. For example, the sharing AP 2302 may generate a frame (e.g., M-AP trigger frame) 2336 for allocating different channels for different shared APs 2304, 2308 to perform data transmissions in their own BSSs using the allocated channels (e.g., the data may be transmitted to from one or more communication apparatuses such as a STA, another AP, or other similar communication apparatus in the BSS of the shared AP 2304 and the BSS of the shared AP 2308, respectively). The sharing AP 2302 may determine the channels to be allocated based on the information or request (e.g., required channel / bandwidth and LL requirements information) in the RTR frames 2326, 2334 sent by the shared APs 2304, 2308. The sharing AP 2302 may then transmit a frame (e.g., M-AP trigger frame) 2336 to the shared APs 2304, 2308 for allocating the channels for the shared APs 2304, 2308. After receiving the frame 2336, each shared AP 2304, 2308 may, respectively, transmit a trigger frame 2338, 2340 to the non-AP STA 2306, 2310 in the shared AP’s BSS on the allocated channel. The non-AP STA 2306, 2310 in the BSSs of the shared APs 2304, 2308 may perform uplink communications (e.g., by transmitting UL PPDUs 2342, 2344) with the shared APs 2304, 2308 on the allocated channels, respectively. After the shared APs 2304, 2308 receive the UL PPDUs 2342, 2344 from their respective non-AP STAs 2306, 2310, they may transmit acknowledgement frames 2346, 2348 back to their respective non-AP STAs 2306, 2308 in the BSSs on the respective allocated channels.

[0124] It should be noted that the RTRP frame and RTR frame illustrated in this fourth variant of the third embodiment with multiple shared APs are the same as those in the second variant of the first or third embodiment with a single shared AP illustrated in Figure 15 and 21, or the fourth variant of the first embodiment with multiple shared APs illustrated in Figure 18.

[0126]

[0125] Figure 24 shows a schematic diagram illustrating a channel sharing procedure 2400 involving a sharing AP 2402, a shared AP 2404, a non-AP STA 2406 in the sharing AP’s BSS and a non-AP STA 2410 in the shared AP’s BSS according to a fifth variant of the third embodiment of the present disclosure. In the procedure, shared AP 2404 may broadcast an unsolicited RTR to the sharing AP 2402.

[0127]

[0126] The TXOP-holder AP (AP1) 2404 holding a TXOP 2411 transmits a trigger frame (e.g., BSRP frame) 2412 to associated non-AP STA 2408 to solicit another frame (e.g., BSR frame) 2414 for intra-BSS information gathering 2413 (e.g., obtaining information about uplink traffic for associated STAs) during the TXOP 2411 . If the TXOP 2411 or the remaining TXOP of the TXOP holder AP’s TXOP 2411 is not sufficient, e.g., for a data exchange in the BSS of the shared AP 2404, the TXOP-holder AP 2404 broadcasts a frame (e.g., RTR frame) 2416 requesting resources (e.g., frequency resource) in a future TXOP. The RTR frame 2416 may comprise the information (e.g., required channel / bandwidth and LL requirements information) for allocating the frequency resource in the upcoming C-OFDMA transmission 2417.

[0128]

[0127] During subsequent TXOP 2419 of the sharing AP 2402, the sharing AP (AP2) 2402 may perform a C-OFDMA transmission according to the information or request in the RTR frame 2416 sent by the shared AP 2404. For example, the sharing AP 2402 may generate a frame (e.g., M-AP trigger frame) 2420 for allocating a channel for the shared AP 2404 to perform data transmission in a BSS of the shared AP 2404 (e.g., the data may be transmitted to one or more communication apparatuses in the BSS of the shared AP 2404, such as a STA, another AP, or other similar communication apparatus). The shared AP 2404 may transmit a trigger frame 2424 to the non-AP STA 2408 in the shared AP’s BSS on the allocated channel while the sharing AP 2402 may transmit a trigger frame 2422 to the non-AP STA 2406 in the sharing AP’s BSS on another channel. The non-AP STA 2408 in the shared AP’s BSS and the non-AP STA 2406 in the sharing AP’s BSS may perform uplink communications (e.g., by transmitting UL PPDUs 2428, 2426) with the shared AP 2404 and the sharing AP 2402 on the allocated channel and another channel, respectively. After the shared AP 2404 and the sharing AP 2402 receive the UL PPDUs 2426, 2428, they may transmit acknowledgement frames 2430, 2432 back to their respective non-AP STAs 2406, 2408 in the BSSs on the respective channels.

[0129]

[0128] It should be noted that the RTR frame illustrated in this fifth variant of the third embodiment in Figure 24 may be the same as those in the different variants of the first embodiment and the second embodiment in Figures 8, 9, 15, 17, 18 and 19.

[0130]

[0129] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of each embodiment described above can be partly or entirely realized by an LSI such as an integrated circuit, and each process described in each embodiment may be controlled partly or entirely by the same LSI or a combination of LSIs. The LSI may be individually formed as chips, or one chip may be formed so as to include a part of or all the functional blocks. The LSI may include a data input and output coupled thereto. The LSI here may be referred to as an IC, a system on a chip (SoC), a system LSI, a super LSI, or an ultra LSI depending on a difference in the degree of integration. However, the technique of implementing an integrated circuit is not limited to the LSI and may be realized by using a dedicated circuit, a general-purpose processor, or a special-purpose processor. In addition, an FPGA (Field Programmable Gate Array) that can be programmed after the manufacture of the LSI or a reconfigurable processor in which the connections and the settings of circuit cells disposed inside the LSI can be reconfigured may be used. The present disclosure can be realized as digital processing or analogue processing. If future integrated circuit technology replaces LSIs as a result of the advancement of semiconductor technology or other derivative technology, the functional blocks could be integrated using the future integrated circuit technology. Biotechnology can also be applied.

[0131]

[0130] The present disclosure can be realized by any kind of apparatus, device or system having a function of communication, which is referred to as a communication apparatus.

[0132]

[0131] Some non-limiting examples of such a communication apparatus include a phone (e.g., cellular (cell) phone, smart phone), a tablet, a personal computer (PC) (e.g., laptop, desktop, netbook), a camera (e.g., digital still / video camera), a digital player (digital audio / video player), a wearable device (e.g., wearable camera, smart watch, tracking device), a game console, a digital book reader, a telehealth / telemedicine (remote health and medicine) device, and a vehicle providing communication functionality (e.g., automotive, airplane, ship), and various combinations thereof.

[0132] The communication apparatus is not limited to be portable or movable, and may also include any kind of apparatus, device or system being non-portable or stationary, such as a smart home device (e.g., an appliance, lighting, smart meter, control panel), a vending machine, and any other “things” in a network of an “Internet of Things (loT)”.

[0133]

[0133] The communication may include exchanging data through, for example, a cellular system, a wireless LAN system, a satellite system, etc., and various combinations thereof.

[0134]

[0134] The communication apparatus may comprise a device such as a controller or a sensor which is coupled to a communication device performing a function of communication described in the present disclosure. For example, the communication apparatus may comprise a controller or a sensor that generates control signals or data signals which are used by a communication device performing a communication function of the communication apparatus.

[0135]

[0135] The communication apparatus also may include an infrastructure facility, such as a base station, an access point, and any other apparatus, device or system that communicates with or controls apparatuses such as those in the above non-limiting examples.

[0136]

[0136] It will be understood that while some properties of the various embodiments have been described with reference to a device, corresponding properties also apply to the methods of various embodiments, and vice versa.

[0137]

[0137] In the following paragraphs, certain exemplifying embodiments are explained with reference to terms related to wireless network technology and the present disclosure regarding communication apparatuses and methods for multi-AP coordination, namely:

[0138] Example 1. A first access point (AP) comprising: circuitry, which in operation, generates a first frame within a time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; and a transmitter, which in operation, transmits the first frame to a second AP. Example 2. The first AP of Example 1 , further comprising: a receiver, which in operation, receives a second frame comprising a second signal field allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0139] Example 3. The first AP of Example 1 , wherein the time period is a first transmission opportunity (TXOP) obtained by the first AP, the first AP further comprising: a receiver, which in operation, receives a third frame within a second TXOP of the second AP prior to the first TXOP, the third frame comprising a third signal field carrying an indication to solicit the first frame.

[0140] Example 4. The first AP of Example 1 , further comprising: a receiver, which in operation, receives a third frame from the second AP prior to the time period, the third frame comprising a third signal field carrying an indication to solicit the first frame and a fourth signal field allocating the time period to the first AP to exchange frames in the BSS of the first AP within the time period.

[0141] Example 5. The first AP of Example 1 , wherein, within the time period and prior to generating the first frame, the transmitter transmits a fourth frame to a station in the BSS of the first AP, the first AP further comprising: a receiver, which in operation, receives a fifth frame comprising information relating to the station, wherein the circuitry generates the first frame based on the information relating to the station.

[0142] Example 6. The first AP of Example 5, wherein the circuitry further determines whether the time period is sufficient for transmitting the fourth frame and receiving the fifth frame, and the transmitter transmits the fourth frame to the station in the BSS of the first AP in response to determining that the time period is sufficient, or the transmitter broadcasts the first frame in response to determining that the time period is not sufficient. Example 7. The first AP of any one of Examples 1 to 6, wherein the first frame further comprises a fifth signal field indicating a bandwidth, wherein the circuitry determines the time or frequency resource based on the bandwidth.

[0143] Example 8. A second access point (AP), comprising: a receiver, which in operation, receives a first frame from a first AP of one or more first APs within a time period, the first frame comprising a first signal field indicating a time or frequency resource to exchange data in a basic service set (BSS) of the first AP; circuitry, which in operation, processes the first frame; and a transmitter, which in operation, further transmits a second frame to the first AP, the second frame allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0144] Example 9. The second AP of Example 8, wherein the circuitry generates a third frame, the third frame comprising a third signal field soliciting the first frame from the first AP; and the transmitter transmits the third frame to the first AP prior to the time period.

[0145] Example 10. The second AP of Example 9, wherein the third frame further comprises a fourth signal field allocating the time period to the first AP to exchange frames in the BSS of the first AP within the time period.

[0146] Example 11 . A communication method implemented by a first access point (AP), comprising; generating a first frame within a time period, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; and transmitting the first frame to a second AP.

[0147] Example 12. The communication method of Example 11 , further comprising: determining whether a remaining time period within the time period is sufficient for the transmission of the first frame, wherein the step of transmitting the first frame to the second AP comprises:

[0148] (i) transmitting the first frame to the second AP within the time period in response to determining that the remaining time period is sufficient; or

[0149] (ii) broadcasting the first frame in response to determining that the remaining time period is not sufficient for the transmission of the first frame.

[0150] Example 13. The communication method of Example 11 or 12, further comprising: receiving a second frame comprising a second signal field allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0151] Example 14. The communication method of Example 11 or 12, wherein the time period is a first transmission opportunity (TXOP) obtained by the first AP, the method further comprising: receiving a third frame within a second TXOP of the second AP prior to the first TXOP, the third frame comprising a third signal field carrying an indication to solicit the first frame.

[0152] Example 15. The communication method of Example 11 or 12, further comprising: receiving a third frame from the second AP prior to the time period, the third frame comprising a third signal field carrying an indication to solicit the first frame and a fourth signal field allocating the time period to the first AP to exchange frames in the BSS of the first AP within the time period.

[0153] Example 16. The communication method of any one of Examples 11 to15, wherein, within the time period and prior to generating the first frame, the communication method further comprising: transmitting a fourth frame to a station in the BSS of the first AP; receiving a fifth frame comprising information relating to the station, wherein the step of generating the first frame within the time period comprises generating the first frame based on the information relating to the station.

[0154] Example 17. A communication method implemented by a second access point (AP), comprising: receiving a first frame from a first AP of one or more first APs within a time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in a basic service set (BSS) of the first AP; processing the first frame; and transmitting a second frame to the first AP, the second frame allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

[0155] Example 18. The communication method of Example 17, further comprising: generating a third frame, the third frame comprising a third signal field soliciting the first frame from the first AP; and transmitting the third frame to the first AP prior to the time period.

[0156]

[0138] It will be appreciated by a person skilled in the art that numerous variations and / or modifications may be made to the present disclosure as shown in the specific embodiments without departing from the spirit or scope of the disclosure as broadly described. The present embodiments are, therefore, to be considered in all respects illustrative and not restrictive.

Claims

CLAIMS1 . A first access point (AP) comprising: a receiver, which in operation, receives a first trigger frame; circuitry, which in operation, generates a second trigger frame to solicit another frame; and a transmitter, which in operation, transmits the second trigger frame to the one or more stations in a basic service set (BSS) of the first AP in a time period after the first AP receiving the first trigger frame and prior to the first AP and the second AP performing coordinated transmission.

2. The first AP of claim 1 wherein, the receiver further receives the another frame from the stations in response to the second trigger frame, in the time period after receiving the first trigger frame and prior to performing the coordinated transmission with the second AP.

3. The first AP of claim 2 wherein, the second trigger frame is a Buffer Status Report Poll (BSRP) frame, and the another frame is a Buffer Status Report (BSR) frame.

4. The first AP of claim 2, wherein, the time period is a portion of a TXOP obtained by the second AP.

5. The first AP of claim 1 , wherein, the circuitry generates a first frame within the time period obtained by or allocated to the first AP, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in the BSS of the first AP; and the transmitter transmits the first frame to the second AP.

6. The first AP of claim 5, wherein, the receiver receives a second frame comprising a second signal field allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

7. The first AP of claim 1 , wherein the time period is a first transmission opportunity (TXOP) obtained by the first AP, the first AP further comprising: a receiver, which in operation, receives the first trigger frame within a second TXOP of the second AP prior to the first TXOP, the first trigger frame comprising a third signal field carrying an indication to solicit the first frame.

8. The first AP of claim 5, further comprising: a receiver, which in operation, receives the first trigger frame from the second AP prior to the time period, the first trigger frame comprising a third signal field carrying an indication to solicit the first frame and a fourth signal field allocating the time period to the first AP to exchange frames in the BSS of the first AP within the time period.

9. The first AP of claim 5, wherein, within the time period and prior to generating the first frame, the transmitter transmits the second trigger frame to a station in the BSS of the first AP, the first AP further comprising: a receiver, which in operation, receives the another frame comprising information relating to the station, wherein the circuitry generates the first frame based on the information relating to the station.

10. The first AP of claim 9, wherein the circuitry further determines whether the time period is sufficient for transmitting the second trigger frame and receiving the another frame, and the transmitter transmits the second trigger frame to the station in the BSS of the first AP in response to determining that the time period is sufficient, or the transmitter broadcasts the first frame in response to determining that the time period is not sufficient.11 . The first AP of claim 5, wherein the first frame further comprises a fifth signal field indicating a bandwidth, wherein the circuitry determines the time or frequency resource based on the bandwidth.

12. A second access point (AP) comprising: circuity, which in operation, generates the first trigger frame; and; a transmitter, which in operation, transmits the first trigger frame to a first AP, wherein the first trigger frame triggers the first AP to exchange a second trigger frame and another frame solicited by the second trigger frame between the first AP and one or more stations in a basic service set (BSS) of the first AP in a time period after the first AP receiving the first trigger frame and prior to the first AP and the second AP performing coordinated transmission.

13. The second AP of claim 12, wherein the second trigger frame is a Buffer Status Report Poll (BSRP) frame, and the another frame is a Buffer Status Report (BSR) frame.

14. The second AP of claim 12, further comprising: a receiver, which in operation, receives a first frame from the first AP of one or more first APs within the time period, the first frame comprising a first signal field indicating a time or frequency resource required for the first AP to exchange data in the BSS of the first AP, wherein the circuitry processes the first frame; and the transmitter further transmits a second frame to the first AP, the second frame allocating the time or frequency resource to be used by the first AP for exchanging the data in the BSS of the first AP.

15. The second AP of claim 14, wherein the circuitry generates the first trigger frame, the first trigger frame, comprising a third signal field soliciting the first frame from the first AP; and the transmitter transmits the first trigger frame to the first AP prior to the time period.

16. The second AP of claim 15, wherein the first trigger frame, further comprises a fourth signal field allocating the time period to the first AP to exchange frames in the BSS of the first AP within the time period.

17. A communication method implemented by a first access point (AP) comprising: receiving, by a receiver, a first trigger frame; generating, by circuity, a second trigger frame to solicit another frame; and transmitting, by a transmitter, the second trigger frame to one or more stations in a basic service set (BSS) of the first AP in a time period after the first AP receiving the first trigger frame and prior to the first AP and the second AP performing coordinated transmission.

18. A communication method implemented by a second access point (AP) comprising: generating, by circuity, a first trigger frame; and transmitting, by a transmitter, the first trigger frame to a first AP, wherein the first trigger frame triggers the first AP to exchange a second trigger frame and another frame solicited by the second trigger frame between the first AP and one or more stations in a basic service set (BSS) of the first AP in a time period after the first AP receiving the first trigger frame and prior to the first AP and the second AP performing coordinated transmission.

19. A station comprising: a receiver, which in operation, receives, from an access point (AP) which receives a first trigger frame from another AP, a second trigger frame;circuity, which in operation, generates another frame solicited by the second trigger frame; and a transmitter, which in operation, transmits the another frame to the AP, in a time period after the AP receiving the first trigger frame and prior to the AP and the another AP performing coordinated transmission.

20. A communication method implemented by a station comprising: receiving, by a receiver, from an access point (AP) which receives a first trigger frame from another AP, a second trigger frame from an access point (AP); generating, by a circuity, another frame solicited by the second trigger frame; and transmitting, by a transmitter, the another frame to the AP, in a time period after the AP receiving a first trigger frame and prior to the AP and the another AP performing coordinated transmission.

Images