Coordinated time domain multiple access (TDMA) between access points (APs) with different channels

Abstract

This disclosure provides systems, methods, and apparatus, including computer programs encoded on a computer storage medium, for wireless communications including coordinated time domain multiple access (C-TDMA) between access points (APs) having different channels. In one aspect, when C-TDMA is used, a first AP may receive a control message with scheduling information for a transmit opportunity (TXOP) from a second AP that is an owner of the TXOP. The second AP may operate in a particular bandwidth, and the first AP may operate in overlapping portions of the same bandwidth and also in different portions of the bandwidth. The scheduling information may indicate a portion of the TXOP for use by the first AP during the TXOP. During the portion of the TXOP for the first AP, the first AP may perform a clear channel assessment (CCA) for the overlapping portion and a non-overlapping portion, and transmit on both an overlapping bandwidth and a different bandwidth during the TXOP.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 17 / 940,867, filed by SUN et al. on September 8, 2022, entitled “COORDINATED TIMEDOMAIN MULTIPLE ACCESS (TDMA) AMONG ACCESS POINTS (APS) WITH DIFFERENT CHANNELS”, which is assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety. Technical Field

[0003] The following generally relates to wireless communications, including Coordinated Time Domain Multiple Access (C-TDMA) between access points (APs) having different channels. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be multiple access systems capable of supporting communication with multiple users by sharing available system resources, such as time, frequency, and power. A wireless network, such as a WLAN, such as a Wi-Fi (i.e., Institute of Electrical and Electronics Engineers (IEEE) 802.11) network, may include an AP that can communicate with one or more stations (STAs) or mobile devices. The AP may be coupled to a network, such as the Internet, and may enable mobile devices to communicate via the network (or communicate with other devices coupled to the AP). A wireless device may communicate bidirectionally with a network device. For example, in a WLAN, a STA may communicate with an associated AP via DL and UL using one or more communication links. A DL (or forward link) may refer to a communication link from an AP to a station, and a UL (or reverse link) may refer to a communication link from a station to an AP. In the case where a STA and an associated AP are multi-link devices (MLDs), the STA may communicate with an associated AP via DL and UL using multiple different communication links, and each communication link may be a DL (or forward link), or a UL (or reverse link), or a combination thereof. Summary of the invention

[0005] The systems, methods, and devices of the disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0006] One innovative aspect of the subject matter described in the present disclosure may be implemented in a method for wireless communication at a first wireless access point (AP). The method may include: receiving a first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a transmit opportunity (TXOP) from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping in frequency with the second bandwidth and a second frequency portion different in frequency from the second bandwidth; performing a clear channel assessment (CCA) associated with at least the second frequency portion of the first bandwidth during the TXOP; and transmitting one or more packets via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information in accordance with the CCA. The CCA may include detection of ongoing transmissions in the wireless medium based at least in part on energy detection, preamble detection, or both.

[0007] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a device for wireless communication at a first wireless AP. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions may be executable by the processor to cause the device to: receive a first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a TXOP from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping with the second bandwidth in frequency and a second frequency portion different in frequency from the second bandwidth; perform a CCA associated with at least the second frequency portion of the first bandwidth during the TXOP; and according to the CCA, send one or more packets via the first frequency portion and the second frequency portion during at least the first portion of the TXOP granted to the first wireless AP by the scheduling information.

[0008] Another innovative aspect of the subject matter described in the present disclosure may be implemented in an apparatus for wireless communication at a first wireless AP. The apparatus may include: a component for receiving a first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a TXOP from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping in frequency with the second bandwidth and a second frequency portion different in frequency from the second bandwidth; a component for performing a CCA associated with at least the second frequency portion of the first bandwidth during the TXOP; and a component for sending one or more packets via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information in accordance with the CCA.

[0009] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a first wireless AP. The code may include instructions that can be executed by a processor to: receive a first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a TXOP from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping with the second bandwidth in frequency and a second frequency portion different in frequency from the second bandwidth; perform a CCA associated with at least the second frequency portion of the first bandwidth during the TXOP; and send one or more packets via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information according to the CCA.

[0010] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a second control message prior to the first control message, the second control message indicating scheduling information for the second portion of the TXOP prior to the first portion of the TXOP.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for detecting that the first frequency portion may be occupied by transmissions from the second wireless AP during the second portion of the TXOP, and performing a backoff countdown of a backoff procedure for the first frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion may be performed in the first portion of the TXOP after the backoff procedure is completed.

[0012] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for pausing the backoff countdown in response to detecting a transmission from a wireless device.

[0013] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing, during the TXOP, the CCA associated with the first frequency portion in the first portion of the TXOP after the backoff procedure is completed.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: performing a backoff countdown of a backoff procedure in the second frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion may be performed in the first portion of the TXOP after the backoff procedure is completed; and performing the CCA associated with the first frequency portion of the first bandwidth, wherein the one or more packets may be sent according to the CCA associated with both the first frequency portion and the second frequency portion.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: tuning the radio of the first wireless AP to at least one subchannel of the first portion of the first bandwidth to monitor the second control message indicating the scheduling information; and tuning the radio of the first wireless AP to at least one subchannel of the second portion of the first bandwidth in response to obtaining the scheduling information.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing the CCA may include operations, features, components, or instructions for performing the CCA associated with the second frequency portion during an interframe spacing window of the first portion of the TXOP.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing the CCA may include operations, features, components, or instructions for performing the CCA associated with the second frequency portion during the first portion of the TXOP, regardless of whether a backoff countdown for the first wireless AP may have been completed.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a length, frequency, or both of one or more packets to be sent to a first wireless station (STA) based on a threshold count, a threshold duration, or both of the one or more packets to be received from the first wireless STA.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an indication to a second STA of a grant of a sub-portion of the first portion of the TXOP granted to the first wireless AP by the scheduling information, wherein the second STA performs the CCA before transmitting during the sub-portion.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing the CCA associated with the first frequency portion of the first bandwidth using the first radio of the first wireless AP, wherein the CCA associated with the second frequency portion of the first bandwidth may be performed using the second radio of the first wireless AP.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the CCA associated with the second frequency portion of the first bandwidth may be performed after a backoff procedure associated with the second radio is completed.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first wireless AP can have a first basic service set (BSS) and the second wireless AP can have a second BSS.

[0023] The details of one or more specific implementations of the subject matter described in the present disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions in the drawings may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 An example wireless communication system supporting coordinated time domain multiple access (C-TDMA) among access points (APs) having different channels is illustrated.

[0025] Figure 2 An example timing diagram illustrating an example of transmission supporting C-TDMA communications between APs with different channels is shown.

[0026] Figure 3A Example frequency resource allocations supporting C-TDMA among APs with different channels are shown.

[0027] Figure 3B Example frequency resource allocations supporting C-TDMA among APs with different channels are shown.

[0028] Figure 3C Example frequency resource allocations supporting C-TDMA among APs with different channels are shown.

[0029] Figure 4 A timing diagram illustrating an example of communication supporting C-TDMA between APs having different channels is shown.

[0030] Figure 5 A timing diagram illustrating an example of communication supporting C-TDMA between APs having different channels is shown.

[0031] Figure 6 An example diagram of a system supporting C-TDMA between APs with different channels is shown.

[0032] Figure 7 A flow chart of an example method for supporting C-TDMA between APs having different channels is shown.

[0033] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0034] For the purpose of describing the innovative aspects of the present disclosure, the following description refers to certain specific implementations. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The described specific implementations can be implemented in any device, system, or network capable of sending and receiving RF signals in accordance with any of the IEEE 16.11 standards, or any of the IEEE 802.11 standards, Standard, Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution-Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals for communicating within a wireless, cellular or Internet of Things (IoT) network, such as a system utilizing 3G, 4G or 5G, or another implementation or technology thereof.

[0035] Coordinated time domain multiple access (C-TDMA) may allow a group of access points (APs) to share or participate in a single transmission opportunity (TXOP) within a bandwidth. In C-TDMA, a first AP may ensure a TXOP for a bandwidth and share the TXOP with other APs. The APs sharing the TXOP may communicate in turn during corresponding portions of the TXOP according to scheduling information provided by the first AP. Some of the APs sharing the TXOP may operate on overlapping but different frequencies and bandwidths. For example, a first AP having a TXOP may operate on a bandwidth having multiple channels (which may also be referred to as subchannels, such as those defined in IEEE 802.11). The second AP may operate on some of the same channels as the first AP, but may also operate on one or more other channels that do not overlap with the operating bandwidth of the first AP. According to the current method, C-TDMA allows a first AP to share a portion of the bandwidth corresponding to a channel shared between the first AP and the second AP with a second AP. This constraint may prevent the second AP from transmitting or receiving over its entire operating bandwidth. Therefore, the throughput of the second AP may be reduced during the shared TXOP.

[0036] To avoid this reduction in throughput, the second AP may perform a clear channel assessment (CCA) for its corresponding portion of the shared TXOP. The second AP may perform CCA for its operating bandwidth as a whole, including channels shared with the first AP and channels outside the operating bandwidth of the first AP. If the CCA indicates that the medium is idle for transmission during the shared TXOP, the second AP may freely transmit or receive on any portion of its operating bandwidth (such as any channel or channel combination) during the scheduled TXOP according to the scheduling information from the first AP. Therefore, the second AP may use its entire bandwidth during the scheduled portion of the shared TXOP to communicate with the STAs of its BSS. In some specific implementations, the second AP may re-grant a portion of the TXOP to other wireless devices such as other APs or STAs.

[0037] Specific implementations of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. In some implementations, the described techniques may increase network throughput by allowing a scheduled AP (such as a first AP) to share a TXOP with other APs (such as a second AP) that may have non-overlapping bandwidths, thereby allowing the other APs to use additional frequency resources beyond the bandwidth of the scheduled AP. In this way, during the TXOP, the other APs may not have to perform conventional carrier sense multiple access / collision avoidance (CSMA / CA) or enhanced distributed channel access (EDCA) techniques to send and receive data in overlapping and non-overlapping bandwidths. Additionally, by allowing other APs to re-grant a portion of the TXOP to a third wireless device such as another AP or STA, some implementations may allow for increased uplink or downlink throughput and improved efficiency in the utilization of limited time and frequency resources. Various implementations may achieve these and other potential advantages without requiring any of the APs to be aware of STAs associated with other BSSs (OBSSs), without requiring a pre-assigned or dedicated master AP or pre-assigned AP group, or without requiring backhaul coordination between APs participating in the TXOP.

[0038] Figure 1 An example wireless communication system 100 supporting high frequency multi-link support system operation is shown. The wireless communication system 100 may be an example of a wireless local area network (WLAN) or a Wi-Fi network and may include an AP 105 and a plurality of associated STAs 115, which may represent devices such as mobile stations, personal digital assistants (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptop computers, display devices (such as TVs or computer monitors), or printers. The AP 105 and the associated STAs 115 may represent a basic service set (BSS) or an extended service set (ESS). The various STAs 115 in the network are able to communicate with each other through the AP 105. Also shown are a coverage area 110-a of the AP 105-a and a coverage area 110-b of the AP 105-b, each of which may represent a BSA of the wireless communication system 100. An extended network station (not shown) associated with the wireless communication system 100 may be connected to a wired or wireless distribution system that may allow multiple APs 105 to be connected in an ESS.

[0039] STA 115 may be located at the intersection of more than one coverage area 110 and may be associated with more than one AP 105. A collection of a single AP 105 and associated STA 115 may be referred to as a BSS. An ESS is a collection of connected BSSs. A distribution system (not shown) may be used to connect the APs 105 in an ESS. In some implementations, the coverage area 110 of an AP 105 may be divided into sectors (also not shown). The wireless communication system 100 may include APs 105 of different types (such as a metropolitan area network or a home network) with different and overlapping coverage areas 110. Two STAs 115 may also communicate directly via a direct wireless link 125, regardless of whether the two STAs 115 are in the same coverage area 110. Examples of direct wireless links 120 may include Wi-Fi direct connections, Wi-Fi tunneling direct link setup (TDLS) links, and other group connections. The STA 115 and the AP 105 may communicate according to WLAN radio and baseband protocols for the physical layer and the medium access control (MAC) layer from IEEE 802.11 and versions including, but not limited to, 802.11b, 802.11g, 802.11a, 802.11n, 802.11ac, 802.11ad, 802.11ah, 802.11ax, or 802.11be. In some other implementations, a peer-to-peer (P2P) connection or an ad hoc network may be implemented within the wireless communication system 100.

[0040] In some implementations, a STA 115 (or AP 105) may be detected by a central AP 105 but not by other STAs 115 in the coverage area 110 of the central AP 105. For example, one STA 115 may be located at one end of the coverage area 110 of the central AP 105, while another STA 115 may be located at the other end. Therefore, the two STAs 115 may communicate with the AP 105 but may not receive each other's transmissions. This may cause a transmission collision between the two STAs 115 in a contention-based environment such as a carrier sense multiple access with collision avoidance (CSMA / CA) environment, because the STAs 115 may transmit at the same time. A STA 115 whose transmission cannot be identified but is within the same coverage area 110 may be referred to as a hidden node. CSMA / CA may be supplemented by the exchange of a request to transmit (RTS) packet sent by a transmitting STA 115 (or AP 105) and a clear to transmit (CTS) packet sent by a receiving STA 115 (or AP 105). This can alert other devices within range of the transmitter and receiver that they are not transmitting for the duration of the primary transmission. RTS / CTS can therefore help mitigate the hidden node problem.

[0041] The AP 105-b of the wireless communication system 100 may win the contention to obtain access to the wireless medium within the duration of the TXOP. In such a specific implementation, the AP 105-b may be referred to as the TXOP owner AP. According to the C-TDMA technology, the AP 105-b that wins the contention and obtains access to the wireless medium within the duration of the TXOP may share time resources with other APs 105-a, which may also be referred to as participant APs or coordinated APs. The AP 105-b may also be referred to as the TXOP owner AP or scheduling AP. The AP 105-b may divide the TXOP into a plurality of TXOP segments or portions, each TXOP portion including corresponding time resources representing a sub-duration of the TXOP. For example, the AP 105-b may assign, grant or allocate (hereinafter interchangeably used) one or more of the time resources to the AP 105-b, and also allocate each of the one or more remaining time resources to one or more other participant APs (including the AP 105-a). In some implementations, AP 105-b shares all frequency resources with one or more participant APs (including AP 105-a) that have been allocated time resources in a portion of the TXOP. In some other implementations, AP 105-b may allocate different portions of bandwidth to at least some of the participant APs (including AP 105-a).

[0042] The AP 105-a and the STAs associated with the AP 105-b in the coverage area 110-b may receive a control message 130, such as a MU-RTS, from the AP 105-b indicating scheduling information for the TXOP owned by the AP 105-b. The STAs 115 associated with the AP 105-b in the coverage area 110-b that receive the control message 130 may each respond with a CTS 135. In some implementations, the AP 105-a may also respond to the control message 130 with the CTS. After receiving the CTS 135, the AP 105-b may send or receive data communications 140 with the STAs 115 in the coverage area 110-b via downlink (DL) transmission, uplink (UL) reception, or both within the TXOP. The STAs 115 that successfully receive the data communications 140 via the DL may send an acknowledgment to the AP 105-b, for example, using a block acknowledgment (BA) 145.

[0043] AP 105-a may operate in at least a portion of the bandwidth scheduled by AP 105-b within the TXOP. For example, the operating bandwidth of AP 105-a may include an overlapping portion that overlaps in frequency with the bandwidth scheduled by AP 105-b within the TXOP and a non-overlapping portion that is different in frequency from the bandwidth scheduled by AP 105-b within the TXOP. Scheduling information of a control message 130 (RTS or another control message) may indicate a first portion of a TXOP that is granted or scheduled for use by AP 105-a during the TXOP. The first portion of the TXOP may fall within the overlapping portion of the operating bandwidth of AP 105-a. Additionally or alternatively, AP 105-a may send scheduling information for a TXOP owned by AP 105-b. The scheduling information may identify the portion of the TXOP for AP 105-a at or before the beginning of the portion of the TXOP for AP 105-a. For example, the scheduling information may be included in a control message 150 (such as a MU-RTS or another control message).

[0044] During the first portion of the TXOP for AP 105-a, AP 105-a may perform CCA for the overlapping portion of the bandwidth and also for the non-overlapping portion of the bandwidth. If the CCA indicates that the medium is idle for transmission for the first TXOP portion, AP 105-a may transmit on the non-overlapping bandwidth as well as on the overlapping bandwidth. AP 105-b may, for example, use control message 150 to poll AP 105-a or trigger AP 105-a to operate in the first TXOP portion. In response to control message 150, AP 105-a may send CTS 155. AP 105-a may continue data communication 160 with STA 115 associated with AP 105-a within coverage area 110-a via DL transmission, via UL reception, or both. STA 115 that successfully receives data communication 160 via DL transmission may confirm reception by, for example, sending an acknowledgment to AP 105-a using BA 165.

[0045] Figure 2 An example timing diagram 200 is shown illustrating an example of transmission supporting C-TDMA communications between APs having different channels. AP 105-a may be Figure 1 AP 105-b may be Figure 1 STA1 can be an example of AP 105-b. Figure 1 105-a. STA2 may be an example of STA 115 associated with AP 105-a. Figure 1 Example of STA 115 associated with AP 105-b.

[0046] In some implementations, STA1 and zero or more additional STAs may be associated with a first BSS of AP 105-a. STA2 and zero or more additional STAs may be associated with a second BSS of AP 105-b.

[0047] In the example of timing diagram 200, a TXOP owner (AP 105-b) may obtain TXOP 201 and share the TXOP with one or more other coordinated APs (AP 105-a, and optionally one or more additional APs). As further illustrated, TXOP 201 includes multiple parts, phases, or periods, including a first TXOP portion 203 and a second TXOP portion 202.

[0048] For example, reference Figure 3A , Figure 3B and Figure 3C , the operating bandwidth (first bandwidth) of AP 105-a may be different from the operating bandwidth (second bandwidth) of TXOP owner AP 105-b. In one example, the first bandwidth may be a subset of the second bandwidth. In another example, the first bandwidth may include a first frequency portion as a subset of the second bandwidth and a second frequency portion outside the first bandwidth. In yet another example, the first bandwidth may include all second bandwidths (first frequency portions) and additional second frequency portions outside the first bandwidth. The first bandwidth may be continuous or non-continuous in frequency. Similarly, the second bandwidth may be continuous or non-continuous in frequency. In some specific implementations, the first bandwidth may also be the same as the second bandwidth, and they completely overlap in frequency. In this case, AP 105-a and AP 105-b may have the same or different primary channels in frequency. Although these examples illustrate TXOP sharing between APs, the techniques discussed may also be applicable to scenarios in which AP 105-b allocates a portion of a TXOP obtained by AP 105-b to a first device associated with AP 105-b for data exchange between the first device and a second device (such as via a peer-to-peer link between the first device and the second device).

[0049] In some implementations, to obtain TXOP 201, TXOP owner AP 105-b contends for access to a wireless medium on a second bandwidth including a primary operating channel or one or more channels of a primary channel (e.g., they may also be referred to as subchannels when the bandwidth includes multiple subchannels). For example, the second bandwidth may be a broadband wireless channel for AP 105-b and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more and may include a primary 20 MHz channel and one or more secondary channels. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel using, for example, CSMA / CA and enhanced distributed channel access (EDCA) techniques. For a broadband wireless channel such as a bonded channel formed by a primary channel and zero or more secondary channels, TXOP 201 may be obtained at time t1.

[0050] In some implementations, after obtaining the TXOP 201, and to ensure interference-free communication during the TXOP 201, the TXOP owner AP 105-b may further reserve the wireless channel by sending a multi-user request to transmit (MU-RTS) frame 205 to one or more STAs associated with the AP 105-b and one or more APs including the AP 105-a. In some implementations, the MU-RTS frame 205 may also be a control message configured to be received by one or more other APs (e.g., APs of the ESS). The MU-RTS frame 205 is configured to cause at least one of the STAs to send a clear to transmit (CTS) frame 210. Any other wireless communication devices (including the AP 105-a and its associated STAs) that receive one or both of the MU-RTS frame 205 or the CTS frame 210 may set their respective network allocation vectors (NAVs) for the duration indicated in the MU-RTS frame 205 or the CTS frame 210.

[0051] In some implementations, to select one or more other coordinated APs to participate in the TXOP 201, the TXOP owner AP 105-b may optionally perform a TXOP availability indication procedure, such as during a TXOP indication phase, during which the TXOP owner AP 105-b learns of the desire or intent of other APs to participate in the TXOP 201. The TXOP indication phase may end before the MU-RTS frame 205 is sent at time t1. In some implementations, the TXOP indication phase may begin at or after time t1 when the TXOP 201 is obtained. In other examples, the TXOP indication phase may occur when the TXOP 201 is obtained, such as before time t0. In some implementations, during the TXOP indication phase, the AP 105-a may announce the availability of time resources in the TXOP 201. The TXOP owner AP 105-b may have previously learned about other neighboring APs in the vicinity of the AP 105-b based on information in beacons, other management frames, or other control frames received from the other APs. TXOP owner AP 105 - b may proceed to select one or more of the candidate APs, including AP 105 - a , to participate in TXOP 201 .

[0052] Additionally or alternatively, in some implementations, the TXOP owner AP 105-b may already be aware of another AP's desire or willingness to participate in a TXOP owned (or to be owned in the future) by the AP 105-a when the AP 105-a obtains the current TXOP 201. For example, the TXOP owner AP 105-b may determine that another AP will participate in the current TXOP 201 based on a previous execution of the TXOP indication procedure in the TXOP indication phase of a previous TXOP or via out-of-band signaling, such as signaling over a backhaul. In some such implementations, the TXOP owner AP 105-b may select candidate APs to participate in the TXOP 201 before or after obtaining the TXOP 201.

[0053] The TXOP owner AP 105-b may determine an amount of time resources of the TXOP to be allocated to each of the selected APs after selecting the APs. In some implementations, the TXOP owner AP 105-b divides the available time resources of the TXOP 201 into two or more TXOP portions, each TXOP portion including one or more time resources. For example, the TXOP owner AP 105-b may divide the TXOP 201 into two portions, which may be equal or unequal, such as a first TXOP portion 203 for the AP 105-a and a second TXOP portion 202 for the TXOP owner AP 105-b. The first TXOP portion 203 may follow the second TXOP portion 202 in time.

[0054] After selecting an AP to participate in TXOP 201, TXOP owner AP 105-b grants, schedules, or otherwise actually allocates corresponding time resources to the selected AP (such as indicating the allocation of these corresponding time resources). In some implementations, the selection of AP 105-a or the amount of time resources allocated to AP 105-a by AP 105-b may be performed in a manner such as Figure 2 201. In some other implementations, the AP 105-b may skip the MU-RTS frame 205 and the subsequent CTS frame 210 at the beginning of the TXOP 201. In this case, the selection of the AP 105-a or the amount of time resources allocated to the AP 105-a may be indicated in another control message as illustrated by the MU-RTS frame 225 preceding the first TXOP portion 203 allocated to the AP 105-a. For example, after the TXOP indication process and before time t1, the TXOP owner AP 105-b may send a MU-RTS frame 205 including, for each of the selected APs, TXOP scheduling information including an indication of the TXOP portion allocated to the respective APs including the first TXOP portion 203 for the AP 105-a and the second TXOP portion 202 for the TXOP owner AP 105-b. The first TXOP portion 203 may be indicated as time resources that may be used by the respective AP 105-a to transmit data to or receive data from one or more respective associated wireless STAs. The second TXOP portion 202 may be indicated in the third frame as time resources that may be used by the AP 105-b to transmit data to or receive data from one or more respective associated wireless STAs.

[0055] The TXOP owner AP 105-b may send the MU-RTS frame 205 or the MU-RTS frame 225 in a non-high-throughput duplicate PPDU that indicates the time resources allocated to the AP 105-a for the first TXOP portion 203 in each of a plurality of channels of the operating bandwidth for the AP 105-b (such as in each of a plurality of 20 MHz subchannels). In this manner, other APs do not need to operate on the same primary 20 MHz channel to receive and process the MU-RTS frame 205 or the MU-RTS frame 225. In some implementations, the source address field and the BSSID field associated with the MU-RTS frame 205 (such as in a MAC header) are set to the MAC address of the TXOP owner, and the destination address field associated with the MU-RTS frame 205 (such as in a MAC header) is set to the broadcast address.

[0056] Each duplicate copy of the MU-RTS frame 205 or the MU-RTS frame 225 in the non-HT duplicate PPDU may include, for each selected AP in the selected AP, an indication of the TXOP portion allocated to the corresponding AP. For example, each copy of the MU-RTS frame 205 on the 20 MHz subchannel may include a user information field for each selected AP in the selected AP. Each user information field may include a corresponding APID of the corresponding AP. For example, the APID may be a MAC address of the AP, a BSSID associated with the AP, a BSS color associated with the AP, or a short identifier associated with the AP. For the corresponding AP, each user information field may include an indication of the start time, duration, or both of the corresponding allocated time resources. For example, the user information field may include an indication of a symbol, a time slot, or an absolute or relative time at which the allocated time resources start to identify the first TXOP portion 203 for the AP 105-a, and an indication of a symbol, a time slot, or an absolute or relative time at which the allocated time resources start to identify the second TXOP portion 202 for the AP 105-b. Additional indications may be provided in the user information for additional corresponding APs. The user information field may also include a duration of the corresponding allocated time resource, for example, in symbols, time slots, or milliseconds (ms). The duration may be indicated with reference to the MU-RTS frame 205 or the MU-RTS frame 225, or with reference to a timer synchronized across APs (including AP 105-a and AP 105-b), such as a timing synchronization function (TSF) timer. In some implementations, the user information field may indicate a duration allocated to the participant AP within the TXOP 201 obtained by AP 105-b. For example, the duration of the first TXOP portion 203 may be indicated in the user information field associated with AP 105-a. The duration of the first TXOP portion 203 may be indicated in the MU-RTS 205, the MU-RTS 225, or both. Each user information field may also include, for the corresponding selected AP, an indication of frequency resources available for use by the corresponding AP when using the corresponding allocated time resources. For example, the user information field may indicate one or more channels or subchannels (such as one or more 20 MHz channels) or one or more resource units (RUs) or RU sets that the corresponding AP can use when using the allocated time resources. In some specific implementations or instances, TXOP owner AP 105-b and one or more of the other APs (including AP 105-a) may be configured to communicate via C-TDMA and CAP OFDMA simultaneously. In other specific implementations or instances, the MU-RTS frame 205 may allocate all available frequency resources to each of the selected APs for use when using their corresponding allocated time resources.The MU-RTS frame 205 or MU-RTS frame 225 may also include operating bandwidth information (which may also be referred to as operating channel information) of the TXOP owner AP 105-b, such as an indication of the center frequency and system bandwidth, so that the corresponding selected AP can unambiguously derive the frequency resources or spatial resources to be used in the data transmission phase.

[0057] After scheduling allocation via MU-RTS frame 205, at t3, TXOP owner AP 105-b may continue to perform data communications 215 with their respective STAs (including STA2). Data communications 215 may include performing DL communications, enabling UL communications, or both DL and UL. APs with C-TDMA capabilities (including AP 105-a and AP 105-b) may be configured to send and receive data communications, acknowledgement (ACK) frames, and trigger frames during their allocated time resources regardless of their respective NAVs.

[0058] Additionally, STAs compatible with C-TDMA may be configured to be in active listening mode at least during the corresponding allocated time resources, and to enable them to send and receive data communications, ACK frames, and trigger frames regardless of their corresponding NAVs. For example, for data communication 215, the TXOP owner AP 105-b may use the time resources allocated to itself and the BSS during the second TXOP portion 202 starting at time t3 to send or receive one or more data communications of one or more STAs in the BSS of the TXOP owner AP 105-b. The data communication 215 may begin at a SIFS duration after the reception of the CTS frame 210. In some specific implementations, the TXOP owner AP 105-b may use multi-user (MU) orthogonal frequency division multiple access (OFDMA) for transmission. Additionally or alternatively, the TXOP owner AP 105-b may use MU multiple-input multiple-output (MIMO) to send data frames to multiple STAs. Additionally or alternatively, the TXOP owner AP 105 - b may transmit data frames using single user (SU) technology.

[0059] In some such implementations in which the TXOP owner AP 105-b sends one or more DL data communications, the associated STAs may also respond with an ACK frame 220, such as a block ACK (BA), using one or more of the time resources allocated to the TXOP owner AP 105-b and the BSS of the AP 105-b in the first TXOP portion 203. As such, the first TXOP portion 203 allocated to the TXOP owner AP 105-b includes not only time resources for sending DL communications, but also sufficient time resources for the associated STAs to send ACK frames 220, which may be sent a SIFS duration after receipt of the DL communications.

[0060] In addition to or as an alternative to sending DL data communications, the TXOP owner AP 105-b may also receive one or more UL data communications from one or more STAs in the BSS of the AP 105-b in the first TXOP portion 203. For example, the TXOP owner AP 105-b may send a trigger frame during the first TXOP portion 203 that triggers: UL data communication in the form of a MU-PPDU including multiple data frames from multiple STAs using one or more of MU OFDMA or MU MIMO, or UL data communication in the form of a corresponding SU PPDU from each of one or more single STAs sequentially. In some such specific implementations in which the TXOP owner AP 105-b receives the one or more UL data communications, the TXOP owner AP 105-b may also respond with an ACK frame (such as a BA) using one or more of the time resources allocated to the TXOP owner AP 105-b and the BSS of the AP 105-b in the first TXOP portion 203. As such, the first TXOP portion 203 allocated to the TXOP owner AP 105-b includes not only time resources for sending trigger frames and receiving UL communications, but also time resources for sending ACK frames 220, which may be sent a SIFS duration after reception of UL communications.

[0061] In some implementations, before sending any communications, the AP 105-a may perform CCA (which may also be referred to as a CCA operation) on one or more (or all) of the subchannels of the first bandwidth associated with the AP 105-a. For example, in some implementations, the TXOP owner AP 105-a may perform physical carrier sensing and specifically energy detection to determine whether the wireless medium is idle before sending any data, trigger, management, or control frames in the first TXOP portion 203. If the AP 105-a senses that the wireless medium is not idle, the AP 105-a may forgo sending any communications in the time resources allocated to the AP 105-a. In addition to CCA, or as an alternative to CCA, the AP 105-a may perform packet detection on one or more or all of the channels of the first bandwidth of the AP 105-a.

[0062] Similar to the TXOP owner AP 105-b, the first AP 105-a may use the time resources allocated to the first AP 105-a by the AP 105-b during the first TXOP portion 203 to send or receive one or more data communications to or from one or more STAs in the BSS of the AP 105-a. The STAs may be configured to be in an active listening mode at least during the first TXOP portion 203, and such that they may send and receive data communications, ACK frames, and trigger frames regardless of their respective NAVs. In some implementations, there may be a guard (or "non-transmit") interval (e.g., for a SIFS duration) between the time resources allocated to a given one of the APs, such as the second TXOP portion 202, and the adjacent time resources allocated to another one of the APs, such as the first TXOP portion 203, to buffer and prevent interference that may be caused by overlapping communications that may be caused by timing errors.

[0063] At time t5, AP 105-b may send an indication of polling to initiate AP 105-a to use the time resources allocated to AP 105-a. In some implementations, the time resources allocated to AP 105-a, such as the duration exemplified by the first TXOP portion 203, may be indicated by the AP itself in the MU-RTS frame 225 (such as in the case where AP 105-b does not send a MU-RTS frame 205 at the beginning of the TXOP to pre-indicate the allocation). The indication of polling may be provided in a user information field in the MU-RTS frame 225 that identifies the APID associated with AP 105-a. Additionally or alternatively, AP 105-b may send an indication of scheduling information for a TXOP owned by AP 105-b and specifically identifying the first TXOP portion 203 at or before the beginning of the TXOP portion for AP 105-a. For example, AP 105-b may include the scheduling information in the MU-RTS frame 205. The first TXOP portion 203 may be identified by the APID associated with the AP 105-a and the duration of the TXOP portion 203. In this case, the MU-RTS frame 225 may simply refer to the time resources already indicated in the MU-RTS frame 205, or carry another time resource indicated in the time resources allocated to the AP 105-a.

[0064] In response to the MU-RTS frame 225, the AP 105-a may send a CTS 230 to the AP 105-b at time t6 to confirm receipt of the MU-RTS frame 205. The CTS 230 may also be received by other wireless communication devices to confirm that the AP 105-b will use the first TXOP portion 203 for data communication. The other wireless communication devices may include STAs (including STA1) within the BSS of the AP 105-a, other APs that share the TXOP 201, or other APs including the AP 105-b.

[0065] After sending CTS 230, AP 105-a may continue to perform data communication 235 with corresponding STAs (including STA1) in the BSS of AP 105-a at time t7. Data communication 235 may begin a SIFS duration after the sending of CTS 230. Data communication 235 may include performing downlink (DL) communication, enabling uplink (UL) communication, or both DL and UL. In some specific implementations, AP 105-a may use MU OFDMA to transmit. Additionally or alternatively, AP 105-a may use MU MIMO to send data frames to multiple STAs. Additionally or alternatively, AP 105-a may use SU technology to send data frames.

[0066] For example, reference Figure 3A , Figure 3B and Figure 3C , the operating bandwidth (first bandwidth) of AP 105-a may be different from the operating bandwidth (second bandwidth) of TXOP owner AP 105-b. In one example, the first bandwidth may be a subset of the second bandwidth. In another example, the first bandwidth may include a first frequency portion as a subset of the second bandwidth and a second frequency portion outside the first bandwidth. In yet another example, the first bandwidth may include all second bandwidths (first frequency portions) and additional second frequency portions outside the first bandwidth. The first bandwidth may be continuous or non-continuous in frequency. Similarly, the second bandwidth may be continuous or non-continuous in frequency. Although not shown in FIG. 3, in some specific implementations, the first bandwidth may also be the same as the second bandwidth and completely overlap with the second bandwidth in frequency. In such specific implementations, AP 105-a and AP105-b may have the same or different primary channels in frequency.

[0067] Also similar to the TXOP owner AP 105-b, before transmitting communications to any of the AP 105-a's associated STAs, the AP may perform CCA at the beginning of the first TXOP portion 203. The AP 105-a may perform physical carrier sensing and specifically energy detection to determine whether the wireless medium is idle on one or more or all of the subchannels of the first bandwidth before transmitting any data, trigger, management, or control frames during the time resources allocated to the AP 105-a, as described above with reference to the TXOP owner AP 105-b. In addition to or as an alternative to CCA, the AP 105-a may perform packet detection on one or more or all of the channels of the first bandwidth of the AP 105-a.

[0068] Consistent with the techniques described herein, the AP 105-a may have received scheduling information for the TXOP 201 and specifically for the first TXOP portion 203 in the MU-RTS frame 205. In an example where the first bandwidth of the AP 105-a includes a first frequency portion that overlaps with the second bandwidth of the TXOP owner AP 105-b and the first bandwidth additionally includes a second frequency portion that is different from (outside, non-overlapping) the first bandwidth, the AP 105-a may transmit on the second frequency portion during the TXOP 201. For example, the AP 105-a may resume transmitting on one or more 20 MHz channels of the first frequency portion (the overlapping portion) after a PIFS or SIFS delay after sending the CTS 230.

[0069] For the second frequency portion (a different non-overlapping portion), AP 105-a may perform CCA. AP 105-a may not need to perform a backoff procedure in the overlapping first frequency portion, for example because the portion is included in the time and frequency resources scheduled by TXOP owner AP 105-b. However, the AP may need to perform CCA for the first frequency portion, for example, depending on the region or sequence.

[0070] If the CCA indicates that the second frequency portion is idle, the AP 105-a may continue to use the non-overlapping second frequency portion in addition to the first frequency portion during the second TXOP portion 202 to perform data communication 235 with the corresponding STA (including STA1) of the BSS of the AP 105-a. The data communication 235 may include performing downlink (DL) communication, enabling uplink (UL) communication, or both DL and UL. In some specific implementations, the AP 105-a may use MU OFDMA for transmission. Additionally or alternatively, the AP 105-a may use MU MIMO to send data frames to multiple STAs. Additionally or alternatively, the AP 105-a may use SU technology to send data frames. Resources such as resource units allocated for data communication 235 may span the first bandwidth, including both the first frequency portion and the second frequency portion.

[0071] In some such implementations where the AP 105-a sends one or more DL data communications, the associated STAs may also respond with an ACK frame 240, such as a BA, at time t8 using one or more of the time resources allocated to the AP 105-a during the first TXOP portion 203 and the BSS of the AP 105-a in the first TXOP portion 203. Thus, the first TXOP portion 203 allocated to the AP 105-a includes not only time resources for sending DL communications, UL communications, or both, but also includes sufficient time resources for the associated STAs to send ACK frames 240, such as BAs, which may be sent within a SIFS duration after the receipt of the DL communications. Although this example shows that the device is the AP 105-a exchanging data and ACK frames with the associated devices, even if the device is a non-AP device associated with the AP 105-b, the same method of exchanging data and ACK frames with another device via a peer link during the first TXOP portion 203 allocated by the AP 105-b may be used. For example, a peer link may be established by a peer protocol such as Tunneled Direct Link Setup (TDLS) and Soft AP.

[0072] Figure 3A , Figure 3B and Figure 3CExample frequency resource allocations 301, 302, and 303 are shown, respectively, to support C-TDMA between APs having different channels. AP 105-a may be an example of a participant AP in a shared TXOP, such as Figure 1 AP 105-a or Figure 2 AP 105-a of the TXOP. AP 105-b may be an example of a TXOP owner AP in a shared TXOP, such as Figure 1 AP 105-b or Figure 2 AP 105-b.

[0073] refer to Figure 3A , the frequency resource allocation 301 may include a first bandwidth 315 of the AP 105-a, including a primary channel 325. For example, the first bandwidth 315 may be a broadband wireless channel, and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 325 and one or more secondary channels. The primary channel 325 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0074] The primary channels of the APs, including primary channel 320 and primary channel 325, may be used by the respective APs 105-b and 105-a to monitor for incoming packets.

[0075] The frequency resource allocation 301 may also include a second bandwidth 310 for the AP 105-b, including a primary channel 325. For example, the second bandwidth 310 may be a broadband wireless channel and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 320 and one or more secondary channels. The primary channel 325 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0076] Frequency resource allocation 301 illustrates an example frequency resource allocation, where first bandwidth 315 and second bandwidth 310 are the same bandwidth and completely overlap, such that there are no non-overlapping frequency portions. In some implementations, primary channel 320 and primary channel 325 may be the same channel and occupy the same set of frequency resources. In other examples, primary channel 320 and primary channel 325 may be different channels occupying different sets of frequency resources. In some examples, the different sets of frequency resources may be completely different, or may partially overlap.

[0077] Even though the first bandwidth 315 and the second bandwidth 310 are the same bandwidth and share frequency resources, the first bandwidth 315 and the second bandwidth 310 may each be allocated using the same or different resource units (RUs).

[0078] refer to Figure 3B , the frequency resource allocation 302 may include a first bandwidth 315 of the AP 105-a, including a primary channel 350. For example, the first bandwidth 315 may be a broadband wireless channel, and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 350 and one or more secondary channels. The primary channel 350 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0079] The frequency resource allocation 302 may also include a second bandwidth 310 for the AP 105-b, including a primary channel 345. For example, the second bandwidth 310 may be a broadband wireless channel and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 345 and one or more secondary channels. The primary channel 345 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0080] Frequency resource allocation 302 illustrates an example frequency resource allocation in which first bandwidth 315 and second bandwidth 310 at least partially overlap, such that there is a first frequency portion 330 that overlaps with second bandwidth 310, a second frequency portion 335 that is different (non-overlapping, different) in frequency from second bandwidth 310, and a third frequency portion 340 of second bandwidth 310 that is different (non-overlapping, different) in frequency from first bandwidth 315. In some implementations, primary channel 345 and primary channel 350 can be the same channel and occupy the same set of frequency resources of first frequency portion 330. In other examples, primary channel 345 and primary channel 350 can be different channels that occupy different sets of frequency resources of first frequency portion 330. In some examples, the different sets of frequency resources can be completely different, or can partially overlap.

[0081] The primary channels of the APs, including the primary channel 345 and the primary channel 350, may be used by the respective APs 105-b and 105-a to monitor for incoming packets. In some implementations, for a shared TXOP, the primary channel 345 and the primary channel 350 may be in the first frequency portion 330 overlapping between the first bandwidth 315 and the second bandwidth 310. Non-HT repeat PPDUs may be used for signaling exchanges between the APs 105-a and 105-b.

[0082] In some implementations, one or both of the first bandwidth 315 and the second bandwidth 310 may operate using channels in or adjacent to the unlicensed national information infrastructure (U-NII) radio spectrum bands U-NII-5, U-NII-6, U-NII-7, or U-NII-8. Such channels may include 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz bandwidths. In some implementations, the first bandwidth 315 may be a 320 MHz bandwidth such as in one or more of U-NII-5, U-NII-6, U-NII-7, or U-NII-8, and the second bandwidth 310 may be a 320 MHz bandwidth such as in one or more of U-NII-5, U-NII-6, U-NII-7, or U-NII-8.

[0083] In the first frequency portion 330 that overlaps between the first bandwidth 315 and the second bandwidth 310, the first bandwidth 315 and the second bandwidth 310 may each use the same or different resource unit (RU) allocations, for example, for data communications.

[0084] refer to Figure 3C , the frequency resource allocation 303 may include a first bandwidth 315 of the AP 105-a, including a primary channel 370. For example, the first bandwidth 315 may be a broadband wireless channel, and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 370 and one or more secondary channels. The primary channel 370 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0085] The frequency resource allocation 302 may also include a second bandwidth 355 for the AP 105-b, including a primary channel 365. For example, the second bandwidth 355 may be a broadband wireless channel and may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, or more, including the primary channel 345 and one or more secondary channels. The primary channel 365 may be a 20 MHz channel. In other examples, the primary channel may be a 40 MHz, 80 MHz, or 160 MHz channel. The secondary channel may be a 20 MHz, 40 MHz, 80 MHz, or 160 MHz channel.

[0086] Frequency resource allocation 302 illustrates an example frequency resource allocation in which first bandwidth 315 and second bandwidth 310 at least partially overlap. In some implementations, second bandwidth 310 is a portion of the frequency resources of first bandwidth 315 or includes a subset of the frequency resources of the first bandwidth, such that there is a first frequency portion 330 that overlaps with second bandwidth 310 and a second frequency portion 335 that is different (non-overlapping, different) in frequency from second bandwidth 355. In some implementations, primary channel 365 and primary channel 370 can be the same channel and occupy the same set of frequency resources of first frequency portion 330. In other examples, primary channel 365 and primary channel 370 can be different channels that occupy different sets of frequency resources of first frequency portion 330. In some examples, the different sets of frequency resources can be completely different, or can partially overlap.

[0087] In some implementations, one or both of the first bandwidth 315 and the second bandwidth 355 may operate using channels in or adjacent to the unlicensed national information infrastructure (U-NII) radio spectrum bands U-NII-5, U-NII-6, U-NII-7, or U-NII-8. Such channels may include 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz bandwidths. In some implementations, the first bandwidth 315 may be a 40 MHz, 80 MHz, 160 MHz, or 320 MHz bandwidth such as one or more of U-NII-5, U-NII-6, U-NII-7, or U-NII-8, and the second bandwidth 355 may be a 20 MHz, 40 MHz, 80 MHz, 160 MHz bandwidth such as one or more of U-NII-5, U-NII-6, U-NII-7, or U-NII-8 that is less than or narrower than the first bandwidth 315.

[0088] The first bandwidth 315 and the second bandwidth 355 may each use the same or different resource unit (RU) allocations, such as in the first frequency portion 330 that overlaps between the first bandwidth 315 and the second bandwidth 355 for data communication.

[0089] Figure 4 A timing diagram 400 is shown illustrating an example of communication supporting C-TDMA between APs having different channels. AP 105-a may be Figure 1 AP 105-a or Figure 2 , Figure 3A , Figure 3B or Figure 3C AP 105-b may be Figure 1 AP 105-b or Figure 2 , Figure 3A , Figure 3B or Figure 3C Example of AP 105-b.

[0090] The AP 105-a can have an operating bandwidth as the first bandwidth 450. The AP 105-b can have an operating bandwidth as the second bandwidth 455 that overlaps with the first bandwidth 450 for the first frequency portion 451 and is different from (non-overlapping with) the first bandwidth 450 for the second frequency portion 452. In some implementations, the first bandwidth 450 and the second bandwidth 455 can be configured differently, for example, with Figure 3B Frequency resource allocation 302 or Figure 3C One or more of the frequency resource allocations 303 are consistent.

[0091] AP 105-b may be a TXOP owner of TXOP 401 that has secured a wireless medium including a second bandwidth 455 of TXOP 401. During MU-RTS / CTS exchange 405, AP 105-b may provide scheduling information identifying a first TXOP portion 403 for AP 105-a as part of a shared TXOP of TXOP 401. AP 105-b may use second TXOP portion 402. AP 105-b may communicate data communications 410 to STAs of the BSS of AP 105-b, and such STAs may provide acknowledgments such as BA 415 in response.

[0092] AP 105-b and AP 105-a may exchange control signaling 420 at or near the beginning of the first TXOP portion 403. Such control signaling 420 may be in, for example, a non-HT repeated PPDU that may be received by the AP using different channel settings. For example, AP 105-b may send control signaling 420, such as a trigger for AP 105-a to use the first TXOP portion 403, wherein AP 105-a and AP 105-b use primary channels in different frequency resources within the first frequency portion 451. The control signaling 420 may include a MU-RTS sent by AP 105-b and a CTS sent by AP 105-a. AP 105-a may communicate data communications 425 to STAs of the BSS of AP 105-a, and such STAs may provide acknowledgments such as BA 430 in response. AP 105-a may communicate data in both the portion of first bandwidth 450 that overlaps with second bandwidth 455, i.e., first frequency portion 451, and also in the portion of first bandwidth 450 that is different from or non-overlapping with second bandwidth 455. Similarly, acknowledgments such as BA 430 may be sent in both first frequency portion 451 and second frequency portion 452.

[0093] In some examples, the AP 105-a may perform a backoff procedure such as a random backoff procedure and CCA before performing data communication 425 in the first TXOP portion 403. In addition to CCA, or as an alternative to CCA, the AP 105-a may perform packet detection. The AP 105-a may perform the backoff procedure and CCA in the non-overlapping second frequency portion 452, for example, for one or more subchannels within the second frequency portion 452. In some specific implementations, the AP 105-a may use a first radio or primary radio to perform CCA, packet detection, or both on the overlapping first frequency portion 451, and use a second radio or secondary radio to perform CCA, packet detection, or both on the second frequency portion 452. In other examples, the AP 105-a may receive scheduling information from the AP 105-b in the Mu-RTS during the MU-RTS / CTS exchange 405 using a radio of the AP 105-a tuned to receive in at least a portion of the second bandwidth 455, and tune the radio, packet detection logic, or both to perform CCA, packet detection, or both on at least the second frequency portion 452 according to the scheduling information identifying the first TXOP portion 403. The AP 105-a may continue to perform data communication 425 in the first TXOP portion 403 after a countdown of a backoff timer of the backoff procedure and CCA indicates idleness of the non-overlapping second frequency portion 452.

[0094] In some implementations, the AP 105-a can detect that the first frequency portion 451 is occupied by transmissions from the AP 105-b during the second TXOP portion 402, for example, by performing a CCA during the second TXOP portion 402. The AP 105-a can perform, start, or continue a backoff countdown of a backoff procedure for the first frequency portion 451 during the second TXOP portion 402. The backoff countdown can be a new backoff or a continuation of an existing backoff that started before the AP 105-a received the control signaling 420. The CCA associated with the second frequency portion 452 can be performed in the first TXOP portion 403 after the backoff procedure is completed.

[0095] For example, after receiving the scheduling information in the MU-RTS from the AP 105-b during the MU-RTS / CTS exchange 405, the AP 105-a may continue the countdown of the backoff timer of the backoff procedure. In some implementations, the AP 105-a may perform the backoff procedure, such as the countdown of the backoff timer that has already started in the second TXOP portion 402 or the start of a new backoff timer, regardless of the data communication 410 or the BA 415. In some implementations, if the AP 105-a detects a transmission from a device other than the AP 105-b, the AP 105-a may pause the countdown in the second TXOP portion 402. Such a device may be from an overlapping basic service set (OBSS) network. To detect such a transmission, the AP 105-a may use packet-in-packet detection, a change in the received signal level, or both. In some implementations, the AP 105-a may listen for such detection on a primary channel, such as a primary 20 MHz channel of the first frequency portion 451 that overlaps the second bandwidth 455 of the TXOP owner AP 105-b. The AP 105-a may continue to perform data communication 425 in the first TXOP portion 403 after the countdown of the backoff timer of the backoff procedure and the CCA indicates idleness of the non-overlapping second frequency portion 452.

[0096] In another example, if the CCA indicates an idle or free state of the non-overlapping second frequency portion 452 at the beginning of the first TXOP portion 403, the AP 105-a may ignore the countdown of the backoff counter and continue to perform data communications 425 in the first TXOP portion 403. The CCA may be performed during a SIFS or PIFS window before the AP 105-a continues to perform communications, such as data communications 425, during the TXOP portion 403. In other examples, the CCA may be performed during the SIFS window within 420 between the MU-RTS and the CTS. In some implementations, the AP 105-a may have a non-zero backoff counter value but continue to the CCA regardless of the non-zero value.

[0097] Figure 5 A timing diagram 500 is shown illustrating an example of communication supporting C-TDMA between APs having different channels. AP 105-a may be Figure 1 AP 105-a or Figure 2 , Figure 3A , Figure 3B , Figure 3C or Figure 4 AP 105-b may be Figure 1 AP 105-b or Figure 2 , Figure 3A , Figure 3B , Figure 3C or Figure 4 AP 105-c may be a third AP sharing TXOP 501, such as another AP of an ESS that also includes AP 105-a and AP 105-b.

[0098] AP 105-a may have an operating bandwidth as a first bandwidth 565. AP 105-b and AP 105-c may have an operating bandwidth as a second bandwidth 560 that overlaps with the first bandwidth 565.

[0099] The AP 105-b may be a TXOP owner of the TXOP 501 that has secured the wireless medium including the second bandwidth 560 of the TXOP 501. During the MU-RTS / CTS exchange 505, the AP 105-b may provide scheduling information identifying the first TXOP portion 503 for the AP 105-a and the third TXOP portion 504 for the AP 105-c as portions of a shared TXOP of the TXOP 501. The AP 105-b may use the second TXOP portion 502. The AP 105-b may communicate data 510 to the STAs of the BSS of the AP 105-b, and such STAs may provide acknowledgments such as BA 515 in response.

[0100] The AP 105-b and the AP 105-c may exchange control signals 520 at or near the beginning of the third TXOP portion 504. Such control signaling 420 may be in, for example, a non-HT repeated PPDU that may be received by the AP using different channel settings. For example, the AP 105-b may send a control signal 520, such as a MU-RTS for the AP 105-c to use the third TXOP portion 504. The AP 105-b and the AP 105-c may use primary channels in different frequency resources within the second bandwidth 506. The control signal 520 may include a MU-RTS for the AP 105-c sent by the AP 105-b and a CTS sent by the AP 105-c. The AP 105-c may communicate data 525 to the STAs of the BSS of the AP 105-c, and such STAs may provide an acknowledgment, such as a BA 530 in response.

[0101] After the third TXOP portion 504, the AP 105-b and the AP 105-a may exchange control signals 535 at or near the beginning of the first TXOP portion 503. The control signal 535 may be in a non-HT duplicate PPDU sent in a first bandwidth 565 that is a portion or subset of the second bandwidth 560, for example, that may be received by an AP using a different channel setting. In other examples, the control signal 535 may be sent by the AP 105-b on the second bandwidth 560, but a portion of the control signal 535 is received by the AP 105-a on the first bandwidth 565. The AP 105-b may send the control signal 535, such as a MU-RTS for the AP 105-a to use the first TXOP portion 503. In some implementations, the AP 105-a and the AP 105-b use primary channels in different frequency resources within the first bandwidth 565. The control signal 535 may include a MU-RTS from the AP 105-b and a CTS from the AP 105-a. The AP 105-a may communicate data 540 to STAs of the BSS of the AP 105-a, and such STAs may provide, in response, an acknowledgment such as a BA 545. The AP 105-a may communicate data on a first bandwidth 565.

[0102] In some examples, there may be a requirement that, where an AP has shared or granted a portion of an AP's TXOP with one or more other APs, those APs may begin transmitting on channels of their own operating bandwidth, such as 20 MHz channels (subchannels), in a TXOP only if the channels, such as 20 MHz channels, overlap in frequency with previous channels, including the channels (subchannels) of the TXOP owner AP. With this requirement, the bandwidth of each successively scheduled AP within a shared TXOP will have a bandwidth on which it may transmit that is constrained to be no greater than the bandwidth of the immediately preceding AP.

[0103] For example, if the AP that is secondarily scheduled in a TXOP has the minimum operating bandwidth among the non-TXOP owner APs in the shared TXOP, all subsequent non-TXOP owner APs in the TXOP may be able to use no more than the minimum bandwidth during the TXOP, even if the subsequent non-TXOP owner APs have a larger operating bandwidth. In this way, the TXOP owner AP 105-b may schedule the AP 105-a (of the first TXOP portion 503) at or near the end of the TXOP 501, where one or more other participating APs are scheduled within the TXOP 501 with the larger bandwidth, so that the bandwidth of the TXOP is not reduced for the other participating APs.

[0104] For example, the third TXOP portion 504 may be scheduled between the second TXOP portion 502 and the first TXOP portion 503, wherein the AP 105-c uses an operating bandwidth that is equal to or not less than the second bandwidth 560 of the AP 105-b, while the first bandwidth 565 of the AP 105-a is less than or narrower than the first bandwidth 565. As such, the bandwidth available to the AP 105-c during the third TXOP portion 504 may not be constrained by the first TXOP portion 503 for the AP 105-a being scheduled before the third TXOP portion 504 within the TXOP 501. In one example, the AP 105-b may schedule participating APs of the TXOP, such as the AP 105-a and the AP 105-b, from a maximum or widest bandwidth to a minimum or narrowest bandwidth to minimize constraints on bandwidths for the participating APs during the TXOP.

[0105] In some implementations, a participant AP may be constrained or constrain itself to schedule downlink transmissions to a wireless device such that responses (such as BAs or data transmissions) received by the participant AP from the wireless device during the shared TXOP meet a count threshold, a duration threshold, or both. Such a participant AP may include an AP with a different operating bandwidth than the TXOP owner AP. For example, a participant AP may be Figure 1 AP 105-a or Figures 2 to 5 The one or more other wireless devices may include an AP or a STA.

[0106] As part of a shared TXOP, a participant AP may be constrained or constrain itself to schedule downlink transmissions to a wireless device, such as during the portion of the TXOP scheduled by the TXOP owner AP for the participant AP, so that the response received by the participant AP from the wireless device complies with a count threshold, a duration threshold, or both of the rules applicable to TXOP sharing. For example, a participant AP may limit or otherwise control the minimum interval between acknowledgment frames and the total duration from the wireless device or client, for example by adjusting the length and frequency of PPDUs transmitted to the wireless device or client. Controlling the count and duration may allow fairness to other APs that schedule stations of their respective BSSs to comply with the count and duration rules for uplink transmissions during the shared TXOP. These techniques may be applicable to participant APs and TXOP owner APs with different bandwidths, and also when they have the same bandwidth. In addition, these techniques may be applied to C-OFDMA and coordinated scheduling request (C-SR) communications. In some specific implementations, these techniques may also be applied to a TXOP shared to a STA for data exchange between the STA and another STA over a peer link during a shared TXOP. For example, in Figure 1 After AP 105-a in the TXOP wins the TXOP based on competition itself, AP 105-a may share a portion of the TXOP with STA 116. This sharing may enable STA 116 and STA 117 to exchange data between the two STAs over a peer-to-peer link (such as TDLS) during the shared TXOP. In this case, STA 116 may limit or otherwise control the minimum interval between frames and the total duration of frames received from STA 117, for example, by adjusting the length and frequency of PPDUs transmitted to STA 117 to comply with the count and duration rules for frames received during the shared TXOP in a certain region or country.

[0107] In some implementations, a participant AP sharing a TXOP may grant a sub-portion (a sub-portion) or multiple portions of a scheduled TXOP portion of the participant AP to one or more other wireless devices. Such participant APs may include APs with different operating bandwidths than the TXOP owner AP. For example, a participant AP may be Figure 1 AP 105-a or Figures 2 to 5AP105-a. One or more other wireless devices may include an AP or a STA. As part of the grant, the participant AP may schedule transmissions and may be able to schedule more uplink transmissions. In some implementations, in order to be friendly or fair to existing devices on the scene, the participant AP may perform a CCA check in a SIFS or PIFS window to ensure that the medium is idle before re-granting a shared TXOP to the wireless device. The wireless device may also perform a CCA check in the SIFS or PIFS window in the re-granted TXOP to ensure that the medium is idle before transmitting. These techniques are applicable to participant APs and TXOP owner APs with different bandwidths, and also when they have the same bandwidth. Additionally, such techniques may be applied to C-OFDMA and C-SR communications.

[0108] Figure 6 An example diagram of a system 600 including a device 605 supporting C-TDMA between APs having different channels is shown. The device 605 may be an AP such as Figure 1 An example of an AP 105 or an AP such as Figures 2 to 5 AP 105-a of any one of them.

[0109] Device 605 may include components for two-way voice and data communications, including components for sending and receiving communications, such as communications manager 620, network communications manager 610, transceiver 615, antenna 625, memory 630, code 635, processor 640, and inter-AP communications manager 645. These components may be in electronic communication or otherwise coupled (such as operatively, communicatively, functionally, electronically, electrically) via one or more buses, such as bus 650.

[0110] The network communication manager 610 may manage communications with the core network (such as via one or more wired backhaul links). For example, the network communication manager 610 may manage the delivery of data communications for client devices such as one or more STAs 115.

[0111] In some implementations, the device 605 may include a single antenna 625. However, in some other implementations, the device 605 may have more than one antenna 625, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 615 may communicate bidirectionally via one or more antennas 625, a wired or wireless link, as described herein. For example, the transceiver 615 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 615 may also include a modem for modulating packets and providing the modulated packets to one or more antennas 625 for transmission, and for demodulating packets received from one or more antennas 625. The transceiver 615 or the transceiver 615 and the one or more antennas 625 may be examples of a transmitter, a receiver, or any combination thereof, or components thereof.

[0112] The memory 630 may include RAM and ROM. The memory 630 may store computer-readable, computer-executable code 635 including instructions that, when executed by the processor 640, cause the device 605 to perform various functions described herein. In some implementations, the memory 630 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0113] The processor 640 may include an intelligent hardware device (such as a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some specific implementations, the processor 640 may be configured to operate a memory array using a memory controller. In some other specific implementations, the memory controller may be integrated into the processor 640. The processor 640 may be configured to execute computer-readable instructions stored in a memory (such as a memory 630) to enable the device 605 to perform various functions (such as functions or tasks that support coordinated time domain multiple access between APs with different channels). For example, the device 605 or a component of the device 605 may include a processor 640 and a memory 630 coupled to or coupled to the processor 640, and the processor 640 and the memory 630 are configured to perform the various functions described herein.

[0114] The inter-AP communication manager 645 can manage communications with other APs 105 and can include a controller or scheduler for controlling communications with STAs 115 in cooperation with other APs 105. For example, the inter-AP communication manager 645 can coordinate scheduling of TXOP portions of a shared TXOP among APs 105 (e.g., for APs using different channels) for C-TDMA, as further described herein. In some implementations, the inter-AP communication manager 645 can coordinate scheduling of transmissions to APs 105 for various interference mitigation techniques such as beamforming or joint transmission. In some implementations, the inter-AP communication manager 645 can provide an interface to provide communications between APs 105.

[0115] According to examples as disclosed herein, the communication manager 620 may support wireless communications at a first wireless AP. For example, the communication manager 620 may be configured to or otherwise support a component for receiving a first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a TXOP from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping the second bandwidth in frequency and a second frequency portion different in frequency from the second bandwidth. The communication manager 620 may be configured to or otherwise support a component for performing a CCA associated with at least the second frequency portion of the first bandwidth during the TXOP. The communication manager 620 may be configured to or otherwise support a component for sending one or more packets via the first frequency portion and the second frequency portion during at least the first portion of the TXOP granted to the first wireless AP by the scheduling information in accordance with the CCA.

[0116] By including or configuring the communication manager 620 according to examples as described herein, the device 605 can support techniques for coordinated time domain multiple access between APs having different channels.

[0117] Figure 7 1 shows a flowchart illustrating a method 700 for supporting C-TDMA between APs with different channels. The operations of the method 700 may be implemented by an AP or its components as described herein. For example, the operations of the method 700 may be implemented by an AP or its components as described herein. Figures 1 to 6 The described AP (which may also be equivalently referred to as a wireless AP) (eg Figure 1 AP 105-a or Figures 2 to 6 In some implementations, the AP may execute a set of instructions to control the functional elements of the AP to perform the described functions. Additionally or alternatively, the AP may use dedicated hardware to perform various aspects of the described functions.

[0118] At 705, the method may include receiving a first control message indicating scheduling information for at least a first wireless AP to send or receive packets during a TXOP from a second wireless AP operating in a second bandwidth, the first wireless AP operating in a first bandwidth, the first bandwidth including a first frequency portion overlapping in frequency with the second bandwidth and a second frequency portion different in frequency from the second bandwidth. The operations of 705 may be performed according to examples as disclosed herein.

[0119] At 710, the method may include performing a CCA associated with at least a second frequency portion of the first bandwidth during the TXOP. The operations of 710 may be performed according to examples as disclosed herein.

[0120] At 715, the method may include, according to the CCA, transmitting one or more packets via the first frequency portion and the second frequency portion during at least a first portion of a TXOP granted to the first wireless AP by the scheduling information. The operations of 715 may be performed according to examples as disclosed herein.

[0121] The above methods describe possible implementations, and the operations and steps may be rearranged or otherwise modified, and other implementations are possible. In addition, aspects from two or more of the methods may be combined.

[0122] The following provides an overview of various aspects of the disclosure:

[0123] Aspect 1: A method for performing wireless communications at a first wireless AP, the method comprising: receiving a first control message from a second wireless AP operating in a second bandwidth, the first control message indicating scheduling information for at least the first wireless AP to send or receive packets during a transmit opportunity (TXOP), the first wireless AP operating in a first bandwidth, the first bandwidth comprising a first frequency portion overlapping with the second bandwidth in frequency and a second frequency portion different in frequency from the second bandwidth; performing a CCA associated with at least the second frequency portion of the first bandwidth during the TXOP; and, based on the CCA, sending one or more packets via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information.

[0124] Aspect 2: The method according to aspect 1 further comprises: receiving a second control message before the first control message, the second control message indicating scheduling information for a second part of the TXOP before the first part of the TXOP.

[0125] Aspect 3: According to the method described in Aspect 2, the method also includes: detecting that the first frequency part is occupied by transmission from the second wireless AP during the second part of the TXOP; and performing a backoff countdown of a backoff procedure for the first frequency part during the second part of the TXOP, wherein the CCA associated with the second frequency part is performed in the first part of the TXOP after the backoff procedure is completed.

[0126] Aspect 4: The method according to aspect 3, further comprising: pausing the backoff countdown in response to detecting a transmission from a wireless device.

[0127] Aspect 5: The method according to any one of aspects 3 to 4, further comprising: during the TXOP, performing the CCA associated with the first frequency portion in the first part of the TXOP after the backoff procedure is completed.

[0128] Aspect 6: According to the method described in any one of Aspects 2 to 5, the method further includes: performing a backoff countdown of a backoff procedure in the second frequency part during the second part of the TXOP, wherein the CCA associated with the second frequency part is performed in the first part of the TXOP after the backoff procedure is completed; and performing the CCA associated with the first frequency part of the first bandwidth, wherein the one or more packets are sent according to the CCA associated with both the first frequency part and the second frequency part.

[0129] Aspect 7: According to the method described in Aspect 6, the method also includes: tuning the radio of the first wireless AP to at least one subchannel of the first part of the first bandwidth to monitor the second control message indicating the scheduling information; and tuning the radio of the first wireless AP to at least one subchannel of the second part of the first bandwidth in response to obtaining the scheduling information.

[0130] Aspect 8: The method according to any one of aspects 1 to 7, wherein performing the CCA includes: performing the CCA associated with the second frequency portion during an interframe spacing window of the first part of the TXOP.

[0131] Aspect 9: The method according to any one of aspects 1 to 8, wherein performing the CCA includes: performing the CCA associated with the second frequency portion during the first portion of the TXOP regardless of whether a backoff countdown for the first wireless AP has been completed.

[0132] Aspect 10: According to the method described in any one of Aspects 1 to 9, the method also includes: selecting the length, frequency, or both of the one or more packets to be sent to the first wireless STA based on a threshold count, a threshold duration, or both of the one or more packets to be received from the first wireless STA.

[0133] Aspect 11: According to the method described in any one of Aspects 1 to 10, the method further includes: sending an indication to a second STA of a grant of a sub-portion of the first part of the TXOP granted to the first wireless AP by the scheduling information, wherein the second STA performs a CCA before transmitting during the sub-portion.

[0134] Aspect 12: According to the method described in any one of Aspects 1 to 11, the method further includes: using the first radio of the first wireless AP to perform the CCA associated with the first frequency part of the first bandwidth, wherein the CCA associated with the second frequency part of the first bandwidth is performed using the second radio of the first wireless AP.

[0135] Aspect 13: The method of aspect 12, wherein the CCA associated with the second frequency portion of the first bandwidth is performed after a backoff procedure associated with the second radio is completed.

[0136] Aspect 14: The method according to any one of aspects 1 to 13, wherein the first wireless AP has a first basic service set (BSS) and the second wireless AP has a second BSS.

[0137] Aspect 15: An apparatus for performing wireless communications at a first wireless AP, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 1 to 14.

[0138] Aspect 16: An apparatus for wireless communication at a first wireless AP, the apparatus comprising at least one component for performing the method according to any one of aspects 1 to 14.

[0139] Aspect 17: A non-transitory computer-readable medium storing code for wireless communication at a first wireless AP, the code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 14.

[0140] As used herein, the term "determining" encompasses a wide variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database or other data structure), inferring, ascertaining, etc. Additionally, "determining" may include receiving (such as receiving information), accessing (such as accessing data stored in a memory), etc. Additionally, "determining" may include resolving, selecting, choosing, establishing, and other such similar actions.

[0141] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including single members). As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc.

[0142] The various illustrative logical components, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the specific implementations disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. The interchangeability of hardware and software has been generally described in terms of functionality and is illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented using hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0143] The hardware and data processing apparatus for implementing the various illustrative logic components, logic blocks, modules and circuits described in conjunction with the various aspects disclosed herein may be implemented or executed using a general purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by circuits specific to a given function.

[0144] In one or more aspects, the functions described may be implemented using hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents, or in any combination thereof. Specific implementations of the subject matter described in this specification may also be implemented as one or more computer programs, such as one or more modules of computer program instructions encoded on computer storage media for execution by a data processing device or for controlling the operation of a data processing device.

[0145] If implemented in software, the function can be stored or sent using one or more instructions or codes of a computer-readable medium. The process of the method or algorithm disclosed herein can be implemented in a processor executable software module that can reside on a computer-readable medium. Computer-readable media include both computer storage media and communication media, and the communication media include any media that can be implemented to transfer a computer program from one location to another. The storage medium can be any available medium that a computer can access. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, disk storage devices or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. As used herein, disks and optical disks include compact disks (CDs), laser optical disks, optical optical disks, digital versatile disks (DVDs), floppy disks, and blue-ray disks. Disks can reproduce data magnetically, and optical disks can reproduce data optically with lasers. The above combination should also be included in the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as a code and instruction set, or any combination of code and instruction sets, on a machine-readable medium or computer-readable medium, which may be incorporated into a computer program product.

[0146] Various modifications to the specific implementations described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other specific implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the specific implementations shown herein, but should be granted the widest scope consistent with the disclosure, the principles and features disclosed herein.

[0147] Additionally, one of ordinary skill in the art will readily recognize that the terms "upper" and "lower" are sometimes used for ease of describing the drawings and indicate relative positions corresponding to the orientation of the drawings on a correctly oriented page, and may not reflect the correct orientation of any device as implemented.

[0148] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable subcombination. Furthermore, while features may be described above as functioning in some combination and even initially claimed as such, one or more features from a claimed combination may be removed from the combination, and a claimed combination may involve subcombinations or variations of subcombinations.

[0149] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the specific order shown or in a sequential order, or to perform all illustrated operations to achieve the desired result. In addition, the accompanying drawings can schematically depict one or more example processes in the form of a flow chart. However, other operations not depicted can be incorporated into the example processes schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously or between any operations in the illustrated operations. In some environments, multitasking and parallel processing may be advantageous. In addition, the separation of each system component in the specific implementation described above should not be understood as requiring such separation in all specific implementations, but it should be understood that the described program components and systems can usually be integrated together in a single software product, or be packaged in multiple software products. Additionally, other specific implementations are within the scope of the following claims. In some specific implementations, the actions narrated in the claims can be performed in different orders and still achieve the desired result.

Claims

1. An apparatus for wireless communication at a first wireless access point (AP), the apparatus comprising: One or more interfaces, the one or more interfaces being configured to: obtaining, from a second wireless AP operating in a second bandwidth, a first control message indicating scheduling information for at least the first wireless AP to transmit or receive packets during a transmit opportunity (TXOP), the first wireless AP operating in a first bandwidth, the first bandwidth comprising a first frequency portion overlapping in frequency with the second bandwidth and a second frequency portion different in frequency from the second bandwidth; as well as outputting one or more packets via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information; and A processing system, the processing system being configured to: A clear channel assessment (CCA) associated with at least the second frequency portion of the first bandwidth is performed during the TXOP, wherein the one or more packets are output according to the CCA.

2. The apparatus of claim 1, wherein the one or more interfaces are configured to: A second control message is obtained prior to the first control message, the second control message indicating scheduling information for a second portion of the TXOP prior to the first portion of the TXOP.

3. The apparatus of claim 2, wherein the processing system is configured to: detecting that the first frequency portion is occupied by transmissions from the second wireless AP during the second portion of the TXOP; and A backoff countdown of a backoff procedure is performed for the first frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion is performed in the first portion of the TXOP after completion of the backoff procedure.

4. The apparatus of claim 3, wherein the processing system is configured to: In response to detecting a transmission from a wireless device, the backoff countdown is paused.

5. The apparatus of claim 3, wherein the processing system is configured to: During the TXOP, the CCA associated with the first frequency portion is performed in the first portion of the TXOP after the backoff procedure is completed.

6. The apparatus of claim 2, wherein the processing system is configured to: performing a backoff countdown of a backoff procedure in the second frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion is performed in the first portion of the TXOP after completion of the backoff procedure; and The CCA associated with the first frequency portion of the first bandwidth is performed, wherein the one or more packets are sent in accordance with the CCA associated with both the first frequency portion and the second frequency portion.

7. The apparatus of claim 6, wherein the processing system is configured to: tuning a radio of the first wireless AP to at least one subchannel of the first portion of the first bandwidth to monitor for the second control message indicating the scheduling information; and The radio of the first wireless AP is tuned to at least one subchannel of the second portion of the first bandwidth in response to obtaining the scheduling information.

8. The apparatus of claim 1 , wherein to perform the CCA, the processing system is further configured to: The CCA associated with the second frequency portion is performed during an interframe spacing window of the first portion of the TXOP.

9. The apparatus of claim 1 , wherein to perform the CCA, the processing system is further configured to: The CCA associated with the second frequency portion is performed during the first portion of the TXOP regardless of whether a backoff countdown for the first wireless AP has completed.

10. The apparatus of claim 1, wherein the processing system is configured to: A length, a frequency, or both of one or more packets to be sent to a first wireless station (STA) is selected based on a threshold count, a threshold duration, or both of the one or more packets to be received from the first wireless STA.

11. The apparatus of claim 1 , wherein the one or more interfaces are configured to: An indication of a grant of a sub-portion of the first portion of the TXOP granted by the scheduling information to the first wireless AP is output to a second STA, wherein the second STA performs a CCA before transmitting during the sub-portion.

12. The apparatus of claim 1, wherein the processing system is configured to: The CCA associated with the first frequency portion of the first bandwidth is performed using a first radio of the first wireless AP, wherein the CCA associated with the second frequency portion of the first bandwidth is performed using a second radio of the first wireless AP.

13. The apparatus of claim 12, wherein the CCA associated with the second frequency portion of the first bandwidth is performed after a backoff procedure associated with the second radio is completed.

14. The apparatus of claim 1, wherein the first wireless AP uses a first primary subchannel in the first bandwidth, the second wireless AP uses a second primary subchannel in the second bandwidth, and the first primary subchannel is different in frequency from the second primary subchannel.

15. The apparatus according to claim 1, wherein the first wireless AP uses a first primary sub-channel in the first bandwidth, the second wireless AP uses a second primary sub-channel in the second bandwidth, and a frequency of the first primary sub-channel is the same as that of the second primary sub-channel.

16. The apparatus of claim 1, wherein the first wireless AP has a first basic service set (BSS) and the second wireless AP has a second BSS.

17. A method for wireless communication at a first wireless access point (AP), the method comprising: receiving, from a second wireless AP operating in a second bandwidth, a first control message indicating scheduling information for at least the first wireless AP to transmit or receive packets during a transmit opportunity (TXOP), the first wireless AP operating in a first bandwidth, the first bandwidth comprising a first frequency portion overlapping in frequency with the second bandwidth and a second frequency portion different in frequency from the second bandwidth; performing a clear channel assessment (CCA) associated with at least the second frequency portion of the first bandwidth during the TXOP; as well as In accordance with the CCA, one or more packets are transmitted via the first frequency portion and the second frequency portion during at least a first portion of the TXOP granted to the first wireless AP by the scheduling information.

18. The method according to claim 17, further comprising: A second control message is received prior to the first control message, the second control message indicating scheduling information for a second portion of the TXOP prior to the first portion of the TXOP.

19. The method according to claim 18, further comprising: detecting that the first frequency portion is occupied by transmissions from the second wireless AP during the second portion of the TXOP; as well as A backoff countdown of a backoff procedure is performed for the first frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion is performed in the first portion of the TXOP after completion of the backoff procedure.

20. The method according to claim 19, further comprising: In response to detecting a transmission from a wireless device, the backoff countdown is paused.

21. The method according to claim 19, further comprising: During the TXOP, the CCA associated with the first frequency portion is performed in the first portion of the TXOP after the backoff procedure is completed.

22. The method according to claim 18, further comprising: performing a backoff countdown of a backoff procedure in the second frequency portion during the second portion of the TXOP, wherein the CCA associated with the second frequency portion is performed in the first portion of the TXOP after completion of the backoff procedure; as well as The CCA associated with the first frequency portion of the first bandwidth is performed, wherein the one or more packets are sent in accordance with the CCA associated with both the first frequency portion and the second frequency portion.

23. The method according to claim 22, further comprising: tuning a radio of the first wireless AP to at least one subchannel of the first portion of the first bandwidth to monitor for the second control message indicating the scheduling information; as well as The radio of the first wireless AP is tuned to at least one subchannel of the second portion of the first bandwidth in response to obtaining the scheduling information.

24. The method of claim 17, wherein performing the CCA comprises: The CCA associated with the second frequency portion is performed during an interframe spacing window of the first portion of the TXOP.

25. The method of claim 17, wherein performing the CCA comprises: The CCA associated with the second frequency portion is performed during the first portion of the TXOP regardless of whether a backoff countdown for the first wireless AP has completed.

26. The method of claim 17, further comprising: A length, a frequency, or both of one or more packets to be sent to a first wireless station (STA) is selected based on a threshold count, a threshold duration, or both of the one or more packets to be received from the first wireless STA.

27. The method of claim 17, further comprising: An indication of a grant of a sub-portion of the first portion of the TXOP granted by the scheduling information to the first wireless AP is sent to a second STA, wherein the second STA performs a CCA before transmitting during the sub-portion.

28. The method of claim 17, further comprising: The CCA associated with the first frequency portion of the first bandwidth is performed using a first radio of the first wireless AP, wherein the CCA associated with the second frequency portion of the first bandwidth is performed using a second radio of the first wireless AP.

29. The method of claim 28, wherein the CCA associated with the second frequency portion of the first bandwidth is performed after a backoff procedure associated with the second radio is completed.

30. The method of claim 17, wherein the first wireless AP has a first basic service set (BSS) and the second wireless AP has a second BSS.

Images