Reducing spectrum wastage within a basic service set

Abstract

A method for wireless communications by a plurality of stations (STAs) in a basic service set (BSS) is described. The method is implemented in the first STA and includes detecting a first control frame transmitted by at least one STA. The first control frame includes first information regarding frequency resource usage of a first data transmission. The method also includes, based on the first information in the first control frame, determining that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels. In addition, the method includes performing a second transmission to the second STA concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels.

Description

[0001] ADDRESSING DYNAMIC RANGE CHALLENGES DURING NON-PRIMARY CHANNEL ACCESS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to wireless communications, and in particular, to wireless communications associated with non-primary channel access (NPCA), dynamic range, and target receive power.

[0004] BACKGROUND

[0005] Wi-Fi, also known as Wireless Local Area Network (WLAN), is a technology that currently mainly operates in the 2.4 GHz, the 5 GHz band, and the 6 GHz band. There are specifications regulating access points' or mobile terminals' physical (PHY) layer, medium access layer (MAC) layer and other aspects in order to secure compatibility and interoperability between different WLAN entities, e.g., between an access point and mobile terminals, both of which may be referred to as stations (STAs) herein. Wi-Fi is generally operated in license-exempt bands, and as such, communication over Wi-Fi may be subject to interference sources from any number of known and unknown devices. Wi-Fi is commonly used as wireless extensions to fixed broadband access, e.g., in domestic environments and hotspots, like airports, train stations and restaurants.

[0006] Listen before talk (LBT) in IEEE 802.11 WLANs

[0007] Wireless communication devices in Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless local area networks (WLANs) - commonly known as Wi-Fi networks, typically use the listen before talk (LBT) mechanism when operating in license-exempt spectrum, which may also be referred to as carrier sense multiple access with collision avoidance (CSMA / CA), to gain access to the wireless medium. The working procedure of LBT may include various steps. For example, before a transmission can be initiated, a transmitter listens on the wireless medium to determine whether a desired channel is occupied (“busy”) or unoccupied (“idle”) by using an appropriate carrier sensing mechanism. If the channel is found to be idle, the transmission can be initiated with a channel access mechanism that typically involves a random backoff procedure. If the channel is found to be “busy,” the transmitter must defer from transmission and essentially keep sensing the channel until it becomes idle. The communication may be challenging especially in the presence of interference which may occur, for example, due to collisions when other transmitters (e.g., hidden nodes) gain access to the channel at the same time or when there are other systems (wideband or narrowband) operating in partially or completely overlapping channels.

[0008] The IEEE 802.11 WLAN standard allows for reservation of a transmission opportunity (TXOP), which is an interval of time during which a particular station (STA) has the right to initiate frame exchange sequences onto the wireless medium. A TXOP is defined by a starting time and a maximum duration and may include or contain multiple frame exchanges between two or more communicating STAs. For example, a TXOP may include or consist of a control frame exchange plus one or more data transmissions plus one or more corresponding acknowledgement frame transmissions.

[0009] Primary and nonprimary subchannels in IEEE 802.11 WLANs

[0010] A basic service set (BSS) in IEEE 802.11 WLANs comprises an access point (AP) STA which possibly serves one or more non-AP STAs associated with it. Every BSS is characterized by an operating channel which comprises a primary subchannel, which is the common channel of operation for all STAs that are members of the BSS. The primary subchannel is a 20 MHz subchannel. Some frames such as beacon frames are only sent on the primary 20 MHz subchannel. BSSs whose operating channel bandwidths are greater than 20 MHz comprise a primary subchannel as well as nonprimary channels. When a STA in a BSS performs LBT for attempting a transmission over the wireless medium, the allowed transmission bandwidth is determined by first assessing whether the primary 20 MHz subchannel of the BSS operating channel is idle and then assessing and appropriately cascading the nonprimary channels. If the primary 20 MHz subchannel is busy, the STA is not allowed to perform a transmission even if one or more nonprimary subchannels of the BSS operating channel are idle.

[0011] Power pre-correction in trigger-based uplink transmissions in IEEE 802.11 WLANs

[0012] Since the IEEE 802.1 lax amendment, orthogonal frequency division multiple access (OFDMA) is supported in Wi-Fi. Both downlink (DL) OFDMA and uplink (UL) OFDMA are supported, where an AP STA can simultaneously communicate with multiple non-AP STAs using non-overlapping frequency resources. During UL OFDMA, the AP STA first sends a trigger frame to inform the non-AP STAs about their respective resource allocations. Such a trigger frame may include or consists of multiple fields that provide information to the non-AP STAs for undertaking their trigger-based UL transmissions.

[0013] A non-AP STA may be mandated to perform power pre-correction for its triggerbased UL transmission wherein it uses information in the AP transmit (TX) Power field and UL Target Receive Power field contained in the trigger frame sent by the AP STA. The non-AP STA computes the path loss to the AP STA as the difference between the indicated AP TX Power and the received power for the trigger frame. This path loss value is then used by the non-AP STA together with the indicated UL Target Receive Power to set an appropriate TX power for the trigger-based UL transmission. Such power precorrection helps to ensure that the AP STA receives the multiple trigger-based UL transmissions sent by the scheduled non-AP STAs at the desired power levels. Specifically, the power levels of the signals from the different scheduled non-AP STAs may in this way be similar. There are at least two reasons why it is desired that the power levels are reasonably similar for the signals received from the different scheduled non-AP STAs. The first is that this will put less requirements on the analog-to-digital converter (ADC), i.e., the ADC may be implemented with less resolution. The second is that the leakage that will be present in the fast Fourier transform (FFT) due to residual frequency errors for the different received signals will be less severe.

[0014] It is to be noted that in UL OFDMA, the trigger frame including the UL target receive power indication is transmitted by the AP STA using all the 20 MHz subchannels over which the corresponding triggered UL transmissions are to be received from the different non-AP STAs. For bandwidths larger than 20 MHz, the trigger frame is duplicated over each 20 MHz subchannel.

[0015] Nonprimary channel access (NPCA) in IEEE 802.11bn

[0016] IEEE 802.1 Ibn is a next generation major amendment currently under development in IEEE 802.11 task group bn (TGbn). TGbn will correspondingly define and standardize the key features of the future Wi-Fi 8. As per the latest specification framework document of this amendment, TGbn is supposed to define a mode of operation wherein nonprimary subchannels can be accessed in a BSS during the concurrent usage of the BSS’s primary subchannel by an overlapping BSS (OBSS). This mode of operation is termed as nonprimary channel access (NPCA). The following is corresponding text from IEEE Specification Framework for TGbn.

[0017] TGbn defines a mode of operation that enables a STA to access the secondary channel while the primary channel is known to be busy due to OBSS traffic or other TBD conditions.

[0018] • The mode of operation shall not assume that the STA is capable to detect or decode a frame and obtain NA V information of the secondary channel concurrently with the primary channel. • A BSS shall only have a single NPCA primary channel (name TBD) on which the ST A contends while the primary channel of the BSS is known to be busy due to OBSS traffic or other TBD conditions.

[0019] An example illustration of NPCA is shown below in FIG. 1 (e.g., as shown in IEEE 802.11-23 / 2005rl, January 2024, titled “Non-Primary Channel access (NPCA)). A STA in a BSS can opportunistically use nonprimary (denoted as secondary in the figure) subchannels when the primary subchannel is determined to be busy due to OBSS transmissions.

[0020] In recent IEEE 802.11 WLAN standard amendments, AP STAs are mandated to support wide operating bandwidths such as 80 MHz (IEEE 802.1 lax = Wi-Fi 6) or 160 MHz (IEEE 802.1 Ibe = Wi-Fi 7, in 6 GHz), whereas non-AP STAs have no such mandatory bandwidth requirements and may support an operating bandwidth as low as 20 MHz only. As a result, when an ongoing communication in a BSS involves devices with a mismatch in their operating bandwidths, there can be significant spectrum wastage in the BSS. For example, when using EDCA, if a 20 MHz non-AP STA initiates a TXOP to transmit UL to a 160 MHz AP STA using the primary 20 MHz subchannel of the BSS, there will be potentially 140 MHz of bandwidth unused and idle in the BSS. There are currently no methods available to exploit such unused and idle portions of a BSS’s operating bandwidth that may help to avoid spectrum wastage within that BSS during an ongoing communication that only uses a small portion of the BSS operating bandwidth.

[0021] Advanced centralized channel access orchestrated by an AP using orthogonal frequency division multiple access (OFDMA), introduced in Wi-Fi by the IEEE 802.1 lax amendment, may perhaps help maximize spectrum usage in a BSS. However, to use OFDMA effectively, there needs to be either downlink (DL) data intended for multiple STAs pending simultaneously at the AP (in case of DL OFDMA), or there needs to be timely knowledge at the AP regarding uplink (UL) data pending simultaneously at multiple STAs (in case of UL OFDMA). This is commonly understood to be a difficult challenge to overcome in practice, and in real-world Wi-Fi deployments and devices, the conventional de-centralized EDCA continues to be the dominant channel access mode.

[0022] Further, the NPCA concept being discussed in IEEE 802.1 Ibn proposes to opportunistically use nonprimary subchannels in a BSS, when the primary subchannel of the BSS is identified to be busy due to OBSS transmissions. This may help improve the spectrum usage at a system level in a multi-BSS deployment but still does not resolve spectrum wastage issues that may arise within a single BSS - such as the one exemplified above. It is also not straightforward to reuse the NPCA concept from IEEE 802.1 Ibn as is and apply it within a single BSS - for example, to allow opportunistic transmissions on unoccupied subchannels concurrently with ongoing data transmissions on some other subchannels within the same BSS. A key reason being that detecting a data transmission on a first subchannel and concurrently not detecting a data transmission on a second subchannel does not necessarily mean that the second subchannel is unused in the BSS - this is an effect of the hidden node problem.

[0023] FIG. 2 shows an example BSS. If the AP orchestrates uplink (UL) OFDMA from STA1 and STA3, STA2 may not hear (or receive) the data transmission from STA3 due to being located outside the coverage of STA3. Thus, STA2 may incorrectly interpret that the corresponding frequency resources are unused. Detecting a corresponding trigger frame transmitted by the AP prior to the parallel UL data transmissions by STA1 and STA3 may help STA2 to understand (or determine) the intended overall bandwidth usage of the UL data transmissions. However, it may not be possible to ensure that a non-AP STA can always detect and correctly decode trigger frames. For example, the reception may be affected by interference, or the non-AP STA may be in a doze state (i.e., unavailable for reception) for power saving.

[0024] Another reason why the NPCA concept from IEEE 802.1 Ibn may not be directly applicable within a single BSS is the potential need for time and / or frequency synchronization of any opportunistic transmissions on nonprimary subchannels with those of ongoing baseline transmissions on the primary subchannel. This may be important to avoid detrimental interference to the latter’s reception.

[0025] If an NPCA based transmission is permitted during an intra-BSS transmission on a primary subchannel, it is important to ensure acceptable probability of successful reception for both transmissions - the baseline transmission on the primary subchannel as well as the NPCA based transmission on a nonprimary subchannel.

[0026] In a scenario where the receiver of both transmissions is the same device, e.g., an AP STA, there may be severe dynamic range challenges if the difference between received signal powers for both UL signals is large. This problem may arise due to the limited bit width supported by the analog to digital conversion stage in the reception. A similar dynamic range problem would arise if one transmission is DL and the other is UL, where the received signal power at the AP STA for the DL transmission (i.e., self-interference) may be significantly larger than the received signal power of the desired UL signal. SUMMARY

[0027] Some embodiments advantageously provide methods, systems, and apparatuses for management of spectrum usage associated with a BSS. Some embodiments provide a method to address the dynamic range challenges that may arise when NPCA is performed in a BSS during intra-BSS traffic on the primary channel.

[0028] One or more embodiments provide methods for a STA in a BSS to perform opportunistic transmissions using unutilized nonprimary subchannels in the BSS when the primary subchannel is busy due to transmissions within the same BSS. In a main embodiment, upon detecting a control frame and determining, from the control frame, the frequency resource usage of an upcoming data transmission in the BSS, a STA performs an opportunistic transmission concurrently with the data transmission and using unutilized and idle frequency resources within the operating bandwidth of the BSS. Some embodiments are related to duration of the opportunistic transmission, nature of the opportunistic transmission, selection of appropriate subchannels for the opportunistic transmission, signaling, rules and restrictions for the opportunistic transmission, etc.

[0029] Some embodiments provide methods for an AP STA to orchestrate the NPCA based transmissions in its BSS in scenarios where dynamic range challenges may arise. In some other embodiments, an AP STA is configured to transmit a first transmission over the primary subchannel, where the first transmission includes an indication of a target receive power at the AP STA for a potential ‘opportunistic’ NPCA based second transmission on a nonprimary subchannel which may occur during an ongoing third transmission over the primary subchannel. Other embodiments provide non-AP STAs that may undertake NPCA based transmissions using the indication provided by the AP STA in the first transmission. Some embodiments address dynamic range challenges at an AP STA that is involved in NPCA operation, for example, during intra-BSS traffic on the primary channel.

[0030] One or more embodiments are beneficial at least because spectrum wastage within a BSS may be reduced and overall throughput and latency performance may be improved.

[0031] Furthermore, one or more embodiments can help with addressing dynamic range challenges at an AP STA that is involved in NPCA operation, for example, during intra- BSS traffic on the primary channel.

[0032] According to an aspect, a method for wireless communications by a plurality of stations (STAs) in a basic service set (BSS) is described. The BSS is characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels. The plurality of STAs includes a first STA and a second STA. The method is implemented in the first STA and includes detecting a first control frame transmitted by at least one STA of the plurality of STAs. The at least one STA is different from the first STA, and the first control frame includes first information regarding frequency resource usage of a first data transmission. The method also includes, based on the first information in the first control frame, determining that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels. In addition, the method includes performing a second transmission to the second STA concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels.

[0033] In some embodiments, the method further includes detecting a second control frame that is transmitted by at least one STA of the plurality of STAs. The at least one STA is different from the first STA, and the second control frame is detected either within a first predetermined time before or a second predetermined time after detecting the first control frame. The second control frame includes second information regarding frequency resource usage of the first data transmission.

[0034] In some other embodiments, the second transmission is completed within an estimated duration of the first data transmission.

[0035] In some embodiments, the estimated duration is based on either the first information or the second information or both.

[0036] In some other embodiments, the second transmission is a control frame transmission.

[0037] In some embodiments, the control frame transmission one of is a request to send (RTS) frame, comprises buffer status information of data pending at the first STA, and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

[0038] In some other embodiments, the second transmission is a second data transmission. In some embodiments, the second data transmission is permitted only for a predetermined data type.

[0039] In some other embodiments, one of: (A) the first STA is a non-access point station (non-AP STA), and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and (B) the first STA is an access point station (AP STA), and the second transmission corresponds to either a downlink transmission or an AP-to- AP transmission.

[0040] In some embodiments, one or both of: (A) the second transmission is permitted only in a predetermined communication direction; and (B) the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

[0041] In some other embodiments, an intended recipient STA of the first data transmission on the primary subchannel is the second STA.

[0042] In some embodiments, the second STA is an access point station (AP STA).

[0043] In some other embodiments, an intended recipient STA of the first data transmission on the primary subchannel is different from the second STA.

[0044] In some embodiments, the second STA shares information in advance of the second transmission with the first STA regarding capabilities of the second STA to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

[0045] In some other embodiments, if the first STA has multiple unutilized nonprimary subchannels to select from for the second transmission, the method further includes performing subchannel selection based on one or more of: (A) a random selection among candidate subchannels; (B) a speed of accessing the candidate subchannels; (C) a probability of successful transmission; (D) a potential achievable data rate; (E) a location of the candidate subchannels compared with the primary subchannel; and (F) subchannel preference information shared in advance by the second STA for the second transmission.

[0046] In some embodiments, one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA while operating in the BSS.

[0047] In some other embodiments, the first STA is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission.

[0048] In some embodiments, one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.

[0049] In some other embodiments, the method further includes, if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing (OFDM) modulation, aligning OFDM symbol boundaries of the second transmission with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission. In some embodiments, the detected first or second control frame is one of (A) a request to send (RTS) frame; (B) a multi-user RTS (MU-RTS) frame; (C) a clear to send (CTS) frame; (D) a CTS-to-self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0050] In some other embodiments, the detected first or second control frame includes first indication, and the method further includes determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, where the one or more idle frequency resources are usable by the first STA to perform second transmissions.

[0051] In some embodiments, the first STA is a non-access point station (non-AP STA), and the second STA is an access point station (AP STA). The first control frame is transmitted by the AP STA using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels. The first control frame includes a second indication indicating a target receive power at the AP STA for the second transmission. The second transmission is receivable by the AP STA using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel. The method further includes, based on the second indication in the first control frame, determining a transmit power setting for the second transmission to be transmitted to the AP STA and using the determined transmit power setting for the second transmission to the AP STA.

[0052] In some other embodiments, the first data transmission is an uplink transmission within the BSS.

[0053] In some embodiments, both of the second transmission and the first data transmission are received at the AP STA based on the indicated target receive power.

[0054] In some other embodiments, the first data transmission is a downlink transmission within the BSS.

[0055] In some embodiments, the indicated target receive power represents one of (A) a maximum supported receive power at the AP STA for the second transmission; and (B) a minimum supported receive power at the AP STA for the second transmission.

[0056] In some other embodiments, the first control frame includes a third indication that indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0057] According to another aspect, a first station (STA) of a plurality of STAs is described. The plurality of STAs is in a basic service set (BSS) which is characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels. The plurality of STAs includes the first STA and a second STA, and the first STA is configured to detect a first control frame transmitted by at least one STA of the plurality of STAs. The at least one STA is different from the first STA, and the first control frame includes first information regarding frequency resource usage of a first data transmission. The first STA is also configured to, based on the first information in the first control frame, determine that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels. In addition, the first STA is configured to perform a second transmission to the second STA concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels.

[0058] In some embodiments, the first STA is configured to perform one or more of the steps of any one of the embodiments of the method implemented in the first STA. According to one aspect, a method for wireless communications by a plurality of stations (STAs) in a basic service set (BSS) is described. The BSS is characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels, and the plurality of STAs includes a first STA and a second STA (22). The method is implemented in the second STA and includes receiving, from the first STA, a second transmission, the second transmission being performed concurrently with a first data transmission. The first data transmission is associated with a first control frame, and the first control frame includes first information regarding frequency resource usage of the first data transmission. The first information in the first control frame informs that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from one or more nonprimary subchannels. Further, one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels are used for the second transmission.

[0059] In some embodiments, a second control frame is transmitted by at least one STA of the plurality of STAs, where the at least one STA is different from the first STA, and the second control frame is detected either within a first predetermined time before or a second predetermined time after detecting the first control frame. The second control frame includes second information regarding frequency resource usage of the first data transmission. In some other embodiments, the second transmission is completed within an estimated duration of the first data transmission.

[0060] In some embodiments, the estimated duration is based on either the first information or the second information or both.

[0061] In some other embodiments, the second transmission is a control frame transmission.

[0062] In some embodiments, the control frame transmission one of: is a request to send (RTS) frame, comprises buffer status information of data pending at the first STA, and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

[0063] In some other embodiments, the second transmission is a second data transmission.

[0064] In some embodiments, the second data transmission is permitted only for a predetermined data type.

[0065] In some other embodiments, one of: (A) the first STA is a non-access point station (non-AP STA), and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and (B) the first STA is an access point station (AP STA), and the second transmission corresponds to either a downlink transmission or an AP-to- AP transmission.

[0066] In some embodiments, one or both of the second transmission is permitted only in a predetermined communication direction and the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

[0067] In some other embodiments, an intended recipient STA of the first data transmission on the primary subchannel is the second STA.

[0068] In some embodiments, the second STA is an access point station (AP STA).

[0069] In some other embodiments, an intended recipient STA of the first data transmission on the primary subchannel is different from the second STA.

[0070] In some embodiments, the second STA shares information in advance of the second transmission with the first STA regarding capabilities of second STA to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

[0071] In some other embodiments, if the first STA has multiple unutilized nonprimary subchannels to select from for the second transmission, and the method further includes performing subchannel selection based on one or more of: (A) a random selection among candidate subchannels; (B) a speed of accessing the candidate subchannels; (C) a probability of successful transmission; (D) a potential achievable data rate; (E) a location of the candidate subchannels compared with the primary subchannel; and (F) subchannel preference information shared in advance by the second STA for the second transmission.

[0072] In some embodiments, one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA while operating in the BSS.

[0073] In some other embodiments, the first STA is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission.

[0074] In some embodiments, one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.

[0075] In some other embodiments, if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing (OFDM) modulation, OFDM symbol boundaries of the second transmission are aligned with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission.

[0076] In some embodiments, the detected first or second control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user RTS (MU-RTS) frame; (C) a clear to send (CTS) frame; (D) a CTS-to-self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0077] In some other embodiments, the detected first or second control frame includes a first indication, and the method further includes determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, the one or more idle frequency resources being usable by the first STA to perform second transmissions.

[0078] In some embodiments, the first STA is a non-access point station (non-AP STA), and the second STA is an access point station (AP STA). The method further includes transmitting the first control frame using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels. The first control frame includes a second indication indicating a target receive power at the AP STA for the second transmission. The second transmission is receivable by the AP STA using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel.

[0079] In some other embodiments, the method further includes receiving, at the AP STA, the second transmission using the second set of frequency resources simultaneously with an ongoing first data transmission over the primary subchannel. The second transmission is received based on the indicated target receive power.

[0080] In some embodiments, the first data transmission is an uplink transmission within the BSS.

[0081] In some other embodiments, the method further includes receiving, at the AP STA, both of the second transmission and the first data transmission based on the indicated target receive power.

[0082] In some embodiments, the first data transmission is a downlink transmission within the BSS.

[0083] In some other embodiments, the indicated target receive power represents one of

[0084] (A) a maximum supported receive power at the AP STA for the second transmission; and

[0085] (B) a minimum supported receive power at the AP STA for the second transmission.

[0086] In some embodiments, a third indication is included in the first control frame, where the third indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0087] According to another aspect, a second station (STA) of a plurality of STAs is described. The plurality of STAs is in a basic service set (BSS) which is characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels. The plurality of STAs include a first STA and the second STA, and the second STA is configured to receive, from the first STA, a second transmission, where the second transmission is performed concurrently with a first data transmission. The first data transmission being associated with a first control frame, and the first control frame includes first information regarding frequency resource usage of the first data transmission. The first information in the first control frame informs that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels. One or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels are used for the second transmission.

[0088] In some embodiments, the second STA is configured to perform one or more of the steps of any one of the embodiments implemented in the second STA.

[0089] One or more embodiments provide an AP STA that orchestrates NPCA based transmissions in its BSS in scenarios wherein dynamic range challenges may arise. In an embodiment, an AP STA may transmit a first transmission over the primary subchannel, where the first transmission includes an indication of a target receive power at the AP STA for a potential ‘opportunistic’ NPCA based second transmission on a nonprimary subchannel which may occur during an ongoing third transmission over the primary subchannel. Some embodiments provide a non-AP STAs that may undertake NPCA based transmissions using the indication provided by the AP STA in the first transmission.

[0090] According to one aspect, a method for wireless communications in a basic service set (BSS) is described. The BSS includes at least an access point (AP) station (STA) and a non-AP STA. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel. The method is applicable or implemented at the non-AP STA and includes receiving a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel. The first transmission includes an indication indicating a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel. Based on the indication in the first transmission, a transmit power setting is determined for the second transmission to be transmitted to the AP STA using the second set of frequency resources. The method also includes transmitting the second transmission to the AP STA using the determined transmit power, where the second transmission is transmitted simultaneously during an ongoing third transmission over the primary subchannel.

[0091] In some embodiments, the AP STA receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel, and the second transmission is received based on the indicated target receive power.

[0092] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, e.g., sent to the AP STA by a non-AP STA within the BSS.

[0093] In some other embodiments, the AP STA receives both the second and the third transmissions based on the indicated target receive power.

[0094] In some embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA to a non-AP STA within the BSS.

[0095] In some other embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA for the second transmission and a minimum supported receive power at the AP STA for the second transmission. In some embodiments, the AP STA includes a further indication in the first transmission, where the further indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0096] In some other embodiments, the first transmission is a control frame transmission.

[0097] In some embodiments, the control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user (MU)-RTS frame; (C) a clear to send (CTS) frame; (D) a CTS-to- self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0098] In some other embodiments, the first transmission is a management frame transmission.

[0099] In some embodiments, the management frame is a beacon frame.

[0100] According to an aspect, a non-AP STA configured for wireless communications in a basic service set (BSS) is described. The BSS includes at least an access point (AP) station (STA) and the non-AP STA. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel. The non-AP STA is configured to receive a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel. The first transmission includes an indication indicating a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel. Based on the indication in the first transmission, a transmit power setting is determined for the second transmission to be transmitted to the AP STA using the second set of frequency resources. The non-AP STA is also configured to transmitting the second transmission to the AP STA using the determined transmit power, where the second transmission is transmitted simultaneously during an ongoing third transmission over the primary subchannel.

[0101] In some embodiments, the AP STA receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel, and the second transmission is received based on the indicated target receive power.

[0102] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, e.g., sent to the AP STA by a non-AP STA within the BSS.

[0103] In some other embodiments, the AP STA receives both the second and the third transmissions based on the indicated target receive power. In some embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA to a non-AP STA within the BSS.

[0104] In some other embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA for the second transmission and a minimum supported receive power at the AP STA for the second transmission.

[0105] In some embodiments, the AP STA includes a further indication in the first transmission, where the further indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0106] In some other embodiments, the first transmission is a control frame transmission.

[0107] In some embodiments, the control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user (MU)-RTS frame; (C) a clear to send (CTS) frame; (D) a CTS-to- self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0108] In some other embodiments, the first transmission is a management frame transmission.

[0109] In some embodiments, the management frame is a beacon frame.

[0110] According to one aspect, a method for wireless communications in a basic service set (BSS) is described. The BSS includes at least an access point (AP) station (STA) and a non-AP STA. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel. The method is applicable or implemented at the AP STA and includes transmitting a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel and including an indication in the first transmission. The indication indicates a target receive power at the AP STA for a second transmission that can be received by the AP STA using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel.

[0111] In some embodiments, the AP STA receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel, and the second transmission is received based on the indicated target receive power.

[0112] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, e.g., sent to the AP STA by a non-AP STA within the BSS.

[0113] In some other embodiments, the AP STA receives both the second and the third transmissions based on the indicated target receive power. In some embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA to a non-AP STA within the BSS.

[0114] In some other embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA for the second transmission and a minimum supported receive power at the AP STA for the second transmission.

[0115] In some embodiments, the AP STA includes a further indication in the first transmission, where the further indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0116] In some other embodiments, the first transmission is a control frame transmission.

[0117] In some embodiments, the control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user (MU)-RTS frame; (C) a clear to send (CTS) frame; (D) a CTS-to- self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0118] In some other embodiments, the first transmission is a management frame transmission.

[0119] In some embodiments, the management frame is a beacon frame.

[0120] According to another aspect, an access point (AP) station (STA) configured for wireless communications in a basic service set (BSS) is described. The BSS includes at least the AP STA and a non-AP STA. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel. The AP STA is configured to transmit a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel and include an indication in the first transmission. The indication indicates a target receive power at the AP STA for a second transmission that can be received by the AP STA using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel.

[0121] In some embodiments, the AP STA receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel, and the second transmission is received based on the indicated target receive power.

[0122] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, e.g., sent to the AP STA by a non-AP STA within the BSS.

[0123] In some other embodiments, the AP STA receives both the second and the third transmissions based on the indicated target receive power. In some embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA to a non-AP STA within the BSS.

[0124] In some other embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA for the second transmission and a minimum supported receive power at the AP STA for the second transmission.

[0125] In some embodiments, the AP STA includes a further indication in the first transmission, where the further indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0126] In some other embodiments, the first transmission is a control frame transmission.

[0127] In some embodiments, the control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user (MU)-RTS frame; (C) a clear to send (CTS) frame; (D) a CTS-to- self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0128] In some other embodiments, the first transmission is a management frame transmission.

[0129] In some embodiments, the management frame is a beacon frame.

[0130] BRIEF DESCRIPTION OF THE DRAWINGS

[0131] A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

[0132] FIG. 1 shows example nonprimary channel access;

[0133] FIG. 2 shows an example BSS;

[0134] FIG. 3 is a schematic diagram of an example network architecture illustrating a communication system according to the principles in the present disclosure;

[0135] FIG. 4 is a block diagram of an AP communicating with a non-AP STA over an at least partially wireless connection according to some embodiments of the present disclosure;

[0136] FIG. 5 is a flowchart of an example process in first STA according to some embodiments of the present disclosure;

[0137] FIG. 6 is a flowchart of an example process in a second STA according to some embodiments of the present disclosure;

[0138] FIG. 7 is a flowchart of another example process in first STA according to some embodiments of the present disclosure; FIG. 8 is a flowchart of another example process in a second STA according to some embodiments of the present disclosure;

[0139] FIG. 9 shows an example opportunistic UL transmission performed on an unutilized nonprimary subchannel during an ongoing UL transmission on a primary subchannel according to some embodiments of the present disclosure;

[0140] FIG. 10 shows another example opportunistic UL transmission performed on an unutilized nonprimary subchannel during an ongoing peer-to-peer (P2P) transmission on the primary subchannel between two non-AP STAs according to some embodiments of the present disclosure;

[0141] FIG. 11 shows an example of NPCA during intra-BSS traffic on primary channel according to some embodiments of the present disclosure;

[0142] FIG. 12 shows an example indication indicating target receive power for NPCA based UL transmission in a trigger frame according to some embodiments of the present disclosure;

[0143] FIG. 13 shows an example indication indicating target receive power for NPCA based UL transmission in a CTS frame according to some embodiments of the present disclosure; and

[0144] FIG. 14 shows an example indication indicating target receive power for NPCA based UL transmission in a CTS-to-self frame according to some embodiments of the present disclosure.

[0145] DETAILED DESCRIPTION

[0146] Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to management of spectrum usage associated with a BSS. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0147] As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and / or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0148] In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate, and modifications and variations are possible of achieving the electrical and data communication.

[0149] In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and / or wireless connections.

[0150] Some embodiments of the present disclosure may be supported by an IEEE 802.11 standard. IEEE 802.11 denotes a set of Wireless Local Area Network (WLAN) air interface standards developed by the IEEE 802.11 committee for short-range communications (e.g., tens of meters to a few hundred meters). Some embodiments may also be supported by systems and / or devices associated with the Third Generation Partnership Project (3GPP). The 3GPP has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD) or user equipment (UE), as well as communication between network nodes and between WDs or UEs. The 3 GPP is also developing standards for Sixth Generation (6G) wireless communication networks. That is, some embodiments of the description can be supported by the above documents (e.g., standard documents). In addition, all the terms disclosed in the present document may be described by the above standard documents.

[0151] In some embodiments, the term “access point” or “AP” is used interchangeably and may comprise, or be, a network node. The AP may include any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell / multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB), donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The AP may also comprise test equipment. The AP may comprise a radio router, a radio transceiver, WiFi access point, wireless local area network (WLAN) access point, a network controller, etc.

[0152] In some embodiments, the non-limiting term “device” is used to describe a wireless device (WD) and / or user equipment (UE) that may be used to implement some embodiments of the present disclosure. In some embodiments, the device may be and / or comprise an access point (AP) station (STA). In some embodiments, the device may be and / or comprise a non-access point station (non-AP STA). In some embodiments, the device may be any type of device capable of communicating with a network node, such as an AP, over radio signals. The device may be any radio communication device, target device, a portable device, device-to-device (D2D) device, machine type device or device capable of machine to machine communication (M2M), low-cost and / or low-complexity device, a sensor equipped with a device, a computer, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device, Reduced Capability (RedCap) device, etc.

[0153] A device may be considered a network node and may include physical components, such as processors, allocated processing elements, or other computing hardware, computer memory, communication interfaces, and other supporting computing hardware. The network node may use dedicated physical components, or the node may be allocated use of the physical components of another device, such as a computing device or resources of a datacenter, in which case the network node is said to be virtualized. A network node may be associated with multiple physical components that may be located either in one location or may be distributed across multiple locations.

[0154] Even though the descriptions herein may be explained in the context of one of a Downlink (DL) and an Uplink (UL) communication, it should be understood that the basic principles disclosed may also be applicable to the other of the one of the DL and the UL communication. In some embodiments in this disclosure, the principles may be considered applicable to, e.g., a first STA and, e.g., a second STA. For DL communication, the first STA may be the transmitter, and the second STA may be the receiver. For UL communication, the transmitter may be the second STA, and the receiver may be the first STA In some embodiments, the first STA may be an AP or non-AP STA, and the second STA may be an AP or a non-AP STA.

[0155] Note that although terminology from one particular wireless system, such as, for example, IEEE 802.11, 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE), 5th Generation (5G) and / or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

[0156] Note further, that functions described herein as being performed by one or more of a first STA, second STA, transmitting STA, receiving STA, AP, non-AP STA, wireless device, network node, etc., may be distributed over a plurality of STAs, APs, non-AP STAs, wireless devices, network nodes, etc. In other words, it is contemplated that the functions of the devices described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

[0157] In some embodiments, the term “transmission” is used and may refer to signaling transmitted by a STA such as an AP STA or a non-AP STA or any other device or node described herein. In some other embodiments, the transmission may comprise an “opportunistic transmission” which may refer to a transmission that is performed by a device which, if it were a conventional device, would not be expected or configured to transmit within a predetermined period of time or using a predetermined resource. In some embodiments, the opportunistic transmission is performed during a TXOP associated with or corresponding to a device other than the device performing the opportunistic transmission. As a nonlimiting example, a first STA may detect a first control frame transmitted by the second STA, where the first control frame includes first information regarding frequency resource usage of a first data transmission. The first STA may, based on the first information in the first control frame, determine that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from one or more nonprimary subchannels. In addition, the first STA may perform a second transmission concurrently with the first data transmission and use one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels. The second transmission may be referred to as an opportunistic transmission.

[0158] Further, in or more embodiments, the term “opportunistic transmission” is used and may refer to an opportunistic transmission or other type of transmission. In some embodiments, a transmission (of signaling such as an opportunistic transmission) by a device or node may be received by another device or node. The reception (of the signaling) may be referred to as “opportunistic reception” and may have features that are similar and / or complementary to the “opportunistic transmission.”

[0159] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0160] Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 3 a schematic diagram of the communication system 10, according to one embodiment, constructed in accordance with the principles of the present disclosure. The communication system 10 in FIG. 3 is a nonlimiting example and other embodiments of the present disclosure may be implemented by one or more other systems and / or networks. Referring to FIG. 3, system 10 may comprise a wireless local area network (WLAN). The devices in the system 10 may communicate over one or more spectrums, such as, for example, an unlicensed spectrum, which may include frequency bands typically used by Wi-Fi technology. One or more of the devices may be further configured to communicate over other frequency bands, such as shared licensed frequency bands, etc. The system 10 may include one or more service areas 12a, 12b, etc. (collectively referred to herein as “service area 12”), which may be defined by corresponding access points (APs) 14a, 14b, etc. (collectively referred to herein as “AP STA 14”). A service area 12 may also correspond to and / or be associated with a coverage area, a cell, and / or a basic service set (BSS).

[0161] The AP STAs 14 may or may not be connectable to another network, such as a core network over a wired or wireless connection. The system 10 includes a plurality of non-AP devices, such as, for example, non-AP STAs 16a, 16b, 16c (collectively referred to as non-AP STAs 16). Each of the non-AP STAs 16 may be located in one or more service areas 12 and may be configured to wirelessly connect to one or more AP STA 14. Note that although two AP STAs 14a and 14b and two non-AP STAs 16a and 16b are shown for convenience, the communication system may include many more non-AP STAs 16 and AP STAs 14. Each AP STA 14 may connect to serve / configure / schedule / etc., one or more non-AP STAs 16.

[0162] It should be understood that the system 10 may include additional nodes and / or devices not shown in FIG. 3. In addition, the system 10 may include many more connections and / or interfaces than those shown in FIG. 3. Thus, the elements shown in FIG. 3 are presented for ease of understanding.

[0163] Also, it is contemplated that a non-AP STA 16 can be in communication and / or configured to separately communicate with more than one AP STA 14 and / or more than one type of AP STA 14. Furthermore, an AP STA 14 may be in communication and / or configured to separately communicate with other AP STAs 14, as described herein, which may be via wired and / or wireless communication channels.

[0164] A non-AP STA 16 is configured to include a non-AP STA Management Unit 18, which is configured to perform one or more non-AP STA 16 functions described herein. An AP STA 14 is configured to include an AP STA Management Unit 20, which is configured to perform one or more AP STA 14 functions described herein.

[0165] Example implementations, in accordance with an embodiment, of the AP STA 14 and non-AP STA 16 discussed in the preceding paragraphs will now be described with reference to FIG. 4.

[0166] An AP STA 14 or a non-AP STA 16 may be generally referred to as a STA 22. For example, a first STA 22a may be an AP STA 14, and a second STA 22b may be a non-AP STA 16. System 10 may include one or more additional STAs 22n (which include AP STAs 14 and / or non-AP STAs 16), which may be in communication with STA 22a and / or STA 22b.

[0167] The AP STA 14 includes hardware 30 including a communication interface 32, processing circuitry 34, a processor 36, and memory 38. The communication interface 32 may be configured to communicate with any of the nodes / devices in the system 10 according to some embodiments of the present disclosure, such as with one or more other AP STAs 14 and / or one or more non-AP STAs 16. In some embodiments, the communication interface 32 may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and / or one or more RF transceivers, and / or may be considered a radio interface. In some embodiments, the communication interface 32 may also include a wired interface.

[0168] The processing circuitry 34 may include one or more processors 26 and memory, e.g., memory 38. In addition to a processor 36 and memory 38, the processing circuitry 34 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 36 may be configured to access (e.g., write to and / or read from) the memory 38, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0169] The AP STA 14 may further include software 40 stored internally in, for example, memory 38, or stored in external memory (e.g., database) accessible by the AP STA 14 via an external connection. The software 40 may be executable by the processing circuitry 34. The processing circuitry 34 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by AP STA 14. The memory 38 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 40 may include instructions stored in memory 38 that, when executed by the processor 36 and / or AP STA Management Unit 20 causes the processing circuitry 34 and / or configures the AP STA 14 to perform the processes described herein with respect to the AP STA 14.

[0170] Still referring to FIG. 4, the non-AP STA 16 includes hardware 50, which may include a communication interface 52, processing circuitry 54, a processor 56, and memory 58. The communication interface 52 may be configured to communicate with one or more AP STA 14 and / or other STA 22n, such as via wireless connection 35, and / or with other elements in the system 10, according to some embodiments of the present disclosure. In some embodiments, the communication interface 52 may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and / or one or more RF transceivers, and / or may be considered a radio interface. In some embodiments, the communication interface 52 may also include a wired interface. In some embodiments, AP STA 14 may be configured to communicate with another AP STA 14, non-AP STA 16, and / or STA 22n via wireless connection 35 and / or via a wired connection (not shown).

[0171] The processing circuitry 54 may include one or more processors 56 and memory, such as, the memory 58. Furthermore, in addition to a traditional processor and memory, the processing circuitry 54 may comprise integrated circuitry for processing and / or control, e.g., one or more processors and / or processor cores and / or FPGAs (Field Programmable Gate Array) and / or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 56 may be configured to access (e.g., write to and / or read from) the memory 58, which may comprise any kind of volatile and / or nonvolatile memory, e.g., cache and / or buffer memory and / or RAM (Random Access Memory) and / or ROM (Read-Only Memory) and / or optical memory and / or EPROM (Erasable Programmable Read-Only Memory).

[0172] Thus, the non-AP STA 16 may further include software 60 stored internally in, for example, memory 58, or stored in external memory (e.g., database) accessible by the non- AP STA 16 via an external connection. The software 60 may be executable by the processing circuitry 54. The processing circuitry 54 may be configured to control any of the methods and / or processes described herein and / or to cause such methods, and / or processes to be performed, e.g., by the non-AP STA 16. The memory 58 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software may include instructions stored in memory 58 that, when executed by the processor 56 and / or non-AP STA Management Unit 18, causes the processing circuitry 54 and / or configures the non-AP STA 16 to perform the processes described herein with respect to the non-AP STA 16.

[0173] In FIG. 4, the connection between the STAs 22 (i.e., AP STA 14, the non-AP STA 16, and STA 22n) is shown without explicit reference to any intermediary devices or connections. However, it should be understood that intermediary devices and / or connections may exist between these devices, although not explicitly shown.

[0174] Although FIG. 4 shows non-AP STA Management Unit 18 and AP STA Management Unit 20, as being within a processor, it is contemplated that this element may be implemented such that a portion of the element is stored in a corresponding memory within the processing circuitry. In other words, the element may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

[0175] FIG. 5 is a flowchart of an example process in a first STA 22. One or more blocks and / or functions and / or methods performed by the first STA 22 may be performed by one or more elements of the first STA 22 such as by non-AP STA Management Unit 18 in processing circuitry 54, memory 58, processor 56, communication interface 52, (or by AP STA Management Unit 20 in processing circuitry 34, memory 38, processor 36, communication interface 32), etc. according to the example process / method. The first STA 22 is configured to detect (Block SI 00) a first control frame transmitted by at least one STA 22 of the plurality of STAs 22. The at least one STA 22 is different from the first STA 22, and the first control frame includes first information regarding frequency resource usage of a first data transmission. The first STA 22 is also configured to, based on the first information in the first control frame, determine (Block SI 02) that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels. In addition, the first STA 22 is configured to perform (Block SI 04) a second transmission to the second STA 22 concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels.

[0176] In some embodiments, the method further includes detecting a second control frame that is transmitted by at least one STA 22 of the plurality of STAs 22. The at least one STA 22 is different from the first STA 22, and the second control frame is detected either within a first predetermined time before or a second predetermined time after detecting the first control frame. The second control frame includes second information regarding frequency resource usage of the first data transmission.

[0177] In some other embodiments, the second transmission is completed within an estimated duration of the first data transmission.

[0178] In some embodiments, the estimated duration is based on either the first information or the second information or both.

[0179] In some other embodiments, the second transmission is a control frame transmission.

[0180] In some embodiments, the control frame transmission one of: is a request to send (RTS) frame, comprises buffer status information of data pending at the first STA 22, and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

[0181] In some other embodiments, the second transmission is a second data transmission. In some embodiments, the second data transmission is permitted only for a predetermined data type.

[0182] In some other embodiments, one of: (A) the first STA 22 is a non-access point station (non-AP STA) 16, and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and (B) the first STA 22 is an access point station (AP STA) 14, and the second transmission corresponds to either a downlink transmission or an AP-to-AP transmission.

[0183] In some embodiments, one or both of: (A) the second transmission is permitted only in a predetermined communication direction; and (B) the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

[0184] In some other embodiments, an intended recipient STA 22 of the first data transmission on the primary subchannel is the second STA 22.

[0185] In some embodiments, the second STA 22 is an access point station (AP STA) 14.

[0186] In some other embodiments, an intended recipient STA 22 of the first data transmission on the primary subchannel is different from the second STA 22.

[0187] In some embodiments, the second STA 22 shares information in advance of the second transmission with the first STA 22 regarding capabilities of the second STA 22 to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

[0188] In some other embodiments, if the first STA 22 has multiple unutilized nonprimary subchannels to select from for the second transmission, the method further includes performing subchannel selection based on one or more of: (A) a random selection among candidate subchannels; (B) a speed of accessing the candidate subchannels; (C) a probability of successful transmission; (D) a potential achievable data rate; (E) a location of the candidate subchannels compared with the primary subchannel; and (F) subchannel preference information shared in advance by the second STA 22 for the second transmission.

[0189] In some embodiments, one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA 22 while operating in the BSS.

[0190] In some other embodiments, the first STA 22 is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission. In some embodiments, one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.

[0191] In some other embodiments, the method further includes, if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing (OFDM) modulation, aligning OFDM symbol boundaries of the second transmission with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission.

[0192] In some embodiments, the detected first or second control frame is one of: (A) a request to send (RTS) frame; (B) a multi-user RTS (MU-RTS) frame; (C) a clear to send (CTS) frame; (D) a CTS-to-self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0193] In some other embodiments, the detected first or second control frame includes a first indication, and the method further includes determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, where the one or more idle frequency resources are usable by the first STA 22 to perform second transmissions.

[0194] In some embodiments, the first STA 22 is a non-access point station (non-AP STA) 16, and the second STA 22 is an access point station (AP STA) 14. The first control frame is transmitted by the AP STA 14 using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels. The first control frame includes a second indication indicating a target receive power at the AP STA 14 for the second transmission. The second transmission is receivable by the AP STA 14 using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel. The method further includes, based on the second indication in the first control frame, determining a transmit power setting for the second transmission to be transmitted to the AP STA 14 and using the determined transmit power setting for the second transmission to the AP STA 14.

[0195] In some other embodiments, the first data transmission is an uplink transmission within the BSS.

[0196] In some embodiments, both of the second transmission and the first data transmission are received at the AP STA 14 based on the indicated target receive power.

[0197] In some other embodiments, the first data transmission is a downlink transmission within the BSS. In some embodiments, the indicated target receive power represents one of: (A) a maximum supported receive power at the AP STA 14 for the second transmission; and (B) a minimum supported receive power at the AP STA 14 for the second transmission.

[0198] In some other embodiments, the first control frame includes a third indication that indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0199] FIG. 6 is a flowchart of an example process in a second STA 22. One or more blocks and / or functions and / or methods performed by the second STA 22 may be performed by one or more elements of the second STA 22 such as by non-AP STA Management Unit 18 in processing circuitry 54, memory 58, processor 56, communication interface 52, (or by AP STA Management Unit 20 in processing circuitry 34, memory 38, processor 36, communication interface 32) etc. according to the example process / method. The second STA 22 is configured to receive (Block SI 06), from the first STA 22, a second transmission, the second transmission being performed concurrently with a first data transmission, the first data transmission being associated with a first control frame, the first control frame comprising first information regarding frequency resource usage of the first data transmission, the first information in the first control frame informing that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from one or more nonprimary subchannels, wherein one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels are used for the second transmission

[0200] In some embodiments, a second control frame is transmitted by at least one STA 22 of the plurality of STAs 22, where the at least one STA 22 is different from the first STA 22, and the second control frame is detected either within a first predetermined time before or a second predetermined time after detecting the first control frame. The second control frame includes second information regarding frequency resource usage of the first data transmission.

[0201] In some other embodiments, the second transmission is completed within an estimated duration of the first data transmission.

[0202] In some embodiments, the estimated duration is based on either the first information or the second information or both.

[0203] In some other embodiments, the second transmission is a control frame transmission. In some embodiments, the control frame transmission one of: is a request to send (RTS) frame, comprises buffer status information of data pending at the first STA 22, and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

[0204] In some other embodiments, the second transmission is a second data transmission.

[0205] In some embodiments, the second data transmission is permitted only for a predetermined data type.

[0206] In some other embodiments, one of: (A) the first STA 22 is a non-access point station (non-AP STA) 16, and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and (B) the first STA 22 is an access point station (AP STA) 14, and the second transmission corresponds to either a downlink transmission or an AP-to-AP transmission.

[0207] In some embodiments, one or both of the second transmission is permitted only in a predetermined communication direction and the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

[0208] In some other embodiments, an intended recipient STA 22 of the first data transmission on the primary subchannel is the second STA 22.

[0209] In some embodiments, the second STA 22 is an access point station (AP STA) 14.

[0210] In some other embodiments, an intended recipient STA 22 of the first data transmission on the primary subchannel is different from the second STA 22.

[0211] In some embodiments, the second STA 22 shares information in advance of the second transmission with the first STA 22 regarding capabilities of second STA 22 to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

[0212] In some other embodiments, if the first STA 22 has multiple unutilized nonprimary subchannels to select from for the second transmission, and the method further includes performing subchannel selection based on one or more of: (A) a random selection among candidate subchannels; (B) a speed of accessing the candidate subchannels; (C) a probability of successful transmission; (D) a potential achievable data rate; (E) a location of the candidate subchannels compared with the primary subchannel; and (F) subchannel preference information shared in advance by the second STA 22 for the second transmission. In some embodiments, one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA 22 while operating in the BSS.

[0213] In some other embodiments, the first STA 22 is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission.

[0214] In some embodiments, one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.

[0215] In some other embodiments, if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing (OFDM) modulation, OFDM symbol boundaries of the second transmission are aligned with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission.

[0216] In some embodiments, the detected first or second control frame is one of (A) a request to send (RTS) frame; (B) a multi-user RTS (MU-RTS) frame; (C) a clear to send (CTS) frame; (D) a CTS-to-self frame; (E) a CTS-to-AP frame; and (F) a trigger frame.

[0217] In some other embodiments, the detected first or second control frame includes a first indication, and the method further includes determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, the one or more idle frequency resources being usable by the first STA 22 to perform second transmissions.

[0218] In some embodiments, the first STA 22 is a non-access point station (non-AP STA) 16, and the second STA 22 is an access point station (AP STA) 14. The method further includes transmitting the first control frame using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels. The first control frame includes a second indication indicating a target receive power at the AP STA 14 for the second transmission. The second transmission is receivable by the AP STA 14 using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel.

[0219] In some other embodiments, the method further includes receiving, at the AP STA 14, the second transmission using the second set of frequency resources simultaneously with an ongoing first data transmission over the primary subchannel. The second transmission is received based on the indicated target receive power. In some embodiments, the first data transmission is an uplink transmission within the BSS.

[0220] In some other embodiments, the method further includes receiving, at the AP STA 14, both of the second transmission and the first data transmission based on the indicated target receive power.

[0221] In some embodiments, the first data transmission is a downlink transmission within the BSS.

[0222] In some other embodiments, the indicated target receive power represents one of (A) a maximum supported receive power at the AP STA 14 for the second transmission; and (B) a minimum supported receive power at the AP STA 14 for the second transmission.

[0223] In some embodiments, a third indication is included in the first control frame, where the third indication indicates a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0224] FIG. 7 is a flowchart of an example process in a first STA 22 (e.g., a non-AP STA 16). One or more blocks and / or functions and / or methods performed by the second STA 22 may be performed by one or more elements of the second STA 22 such as by non-AP STA Management Unit 18 in processing circuitry 54, memory 58, processor 56, communication interface 52, etc. according to the example process / method. The method is for wireless communications in a basic service set (BSS) that includes at least an access point (AP) station (STA) 14 and a non-AP STA 16. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel, and the method is applicable or implemented at the non-AP STA 16. The first STA 22 (i.e., non-AP STA 16) is configured to receive (Block SI 08) a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel. The first transmission includes an indication indicating a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA 14 using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel. The first STA 22 (i.e., non-AP STA 16) is also configured to, based on the indication in the first transmission, determine (Block SI 10) a transmit power setting for the second transmission to be transmitted to the AP STA using the second set of frequency resources and perform (Block SI 12) the second transmission to the AP STA 14 using the determined transmit power. The second transmission is transmitted simultaneously during an ongoing third transmission over the primary subchannel..

[0225] In some embodiments, the AP STA 14 receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel. The second transmission is received based on the indicated target receive power.

[0226] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, i.e., sent to the AP STA 14 by a non-AP STA 16 within the BSS.

[0227] In some embodiments, the AP STA 14 receives both the second and the third transmissions based on the indicated target receive power.

[0228] In some other embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA 14 to a non-AP STA 16 within the BSS.

[0229] In some embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA 14 for the second transmission and a minimum supported receive power at the AP STA 14 for the second transmission.

[0230] In some other embodiments, the AP STA 14 includes a further indication in the first transmission, the further indication indicating a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0231] In some embodiments, the first transmission is a control frame transmission.

[0232] In some other embodiments, the control frame is one of: a request to send (RTS) frame; a multi-user (MU)-RTS frame; a clear to send (CTS) frame; a CTS-to-self frame; a CTS-to-AP frame; and a trigger frame.

[0233] In some embodiments, the first transmission is a management frame transmission.

[0234] In some other embodiments, the management frame is a beacon frame.

[0235] FIG. 8 is a flowchart of an example process in a second STA 22 (e.g., an AP STA 14). One or more blocks and / or functions and / or methods performed by the first STA 22 may be performed by one or more elements of the first STA 22 such as by AP STA Management Unit 20 in processing circuitry 34, memory 38, processor 36, communication interface 32, etc. according to the example process / method. The method is for wireless communications in a basic service set (BSS) that includes at least an access point (AP) station (STA) 14 and a non-AP STA 16. The BSS operates using a channel that includes at least a primary subchannel and a nonprimary subchannel. The method is applicable or implemented at the AP STA 14. The second STA 22 (i.e., AP STA 14) is configured to perform (Block SI 14) a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel. The second STA 22 (i.e., AP STA 14) is also configured to include (Block SI 16) an indication in the first transmission, where the indication indicates a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA 14 using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel.

[0236] In some embodiments, the AP STA 14 receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel. The second transmission is received based on the indicated target receive power.

[0237] In some other embodiments, the third transmission is an uplink (UL) transmission within the BSS, i.e., sent to the AP STA 14 by a non-AP STA 16 within the BSS.

[0238] In some embodiments, the AP STA 14 receives both the second and the third transmissions based on the indicated target receive power.

[0239] In some other embodiments, the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA 14 to a non-AP STA 16 within the BSS.

[0240] In some embodiments, the indicated target receive power represents one of a maximum supported receive power at the AP STA 14 for the second transmission and a minimum supported receive power at the AP STA 14 for the second transmission.

[0241] In some other embodiments, the AP STA 14 includes a further indication in the first transmission, the further indication indicating a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0242] In some embodiments, the first transmission is a control frame transmission.

[0243] In some other embodiments, the control frame is one of: a request to send (RTS) frame; a multi-user (MU)-RTS frame; a clear to send (CTS) frame; a CTS-to-self frame; a CTS-to-AP frame; and a trigger frame.

[0244] In some embodiments, the first transmission is a management frame transmission. In some other embodiments, the management frame is a beacon frame.

[0245] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for management of spectrum usage associated with a BSS. One or more embodiments are generally described when applied to a wireless communication system based on the IEEE 802.11 WLAN standard, e.g., for ease of understanding. However, the embodiments are not limited as such, and may be applicable to any other standards, communication protocols, systems, etc.

[0246] In some embodiments, various non-AP STAs 16 are described. In some other embodiments, a first non-AP STA 16a may be referred to as a first STA 16a (e.g., a first “STA1”). Similarly, a second non-AP STA 16a may be referred to as a second STA 16b (e.g., a second “STA2”), and a third non-AP STA 16c may be referred to as a third STA 16c (e.g., a third “STA3”). In some embodiments, system 10 refers to a BSS.

[0247] Although some embodiments described herein may refer to STA 16, the embodiments are not limited as such, and STA 16 may refer to any STA 22 such as an AP STA 14. Similarly, in some embodiments, AP STA 14 (or simply STA 14) and / or non-AP STA 16 (or simply STA 16) are used, and any may refer to STA 22.

[0248] One or more embodiments provide methods for a STA 22 in a BSS to perform opportunistic transmissions using unutilized nonprimary subchannels in the BSS when the primary subchannel is busy due to transmissions within the same BSS.

[0249] In an embodiment, upon detecting a control frame and determining, from the control frame, the frequency resource usage of an upcoming data transmission in the BSS, a STA 22 performs an opportunistic transmission concurrently with the data transmission and uses unutilized and idle frequency resources within the operating bandwidth of the BSS. In a related embodiment, the opportunistic transmission is completed within an estimated duration of the data transmission. The estimated duration may be determined (e.g., computed) based on information contained in the detected control frame. The opportunistic transmission may be completed within the duration of the data transmission, e.g., so that all communicating devices in the BSS can return to operation on the primary subchannel in a timely manner, e.g., at the end of the TXOP reserved on the primary subchannel. Fairness, especially with channel access, may be ensured when legacy devices or device incapable of such opportunistic nonprimary channel access are operating in the BSS. In some embodiments, the term “legacy devices” may refer to devices operating based on conventional technology, such as governed by existing IEEE 802.11 standards.

[0250] When using EDC A based channel access in a BSS, a request-to-send (RTS) - clear-to-send (CTS) frame exchange is typically undertaken prior to a data transmission which may help with multiple aspects, e.g., to ensure that the receiver STA(s) is(are) awake and ready for reception, to reserve and protect the TXOP, to prevent hidden node related interference, etc. The RTS and CTS frames may comprise information regarding duration and frequency resource usage of the subsequent data transmission, and a STA 22 that detects either of them may then determine this information. In some embodiments, standardized control frames may be detected and may provide relevant information regarding upcoming data transmissions, such as - RTS frame, multi-user RTS (MU-RTS) frame, CTS frame, CTS-to-self frame, CTS-to-AP frame, Trigger frame, e.g., as described in IEEE 802.11 WLAN standard and / or its amendments.

[0251] When data transmissions are preceded by RTS-CTS control frame exchanges, it may be favorable to detect both the RTS and CTS frames. For example, UL data transmissions may be performed in an 80 MHz BSS. A non-AP STA 16 may transmit an RTS frame over the 80 MHz operating bandwidth, but the AP STA 14 may transmit the CTS frame only over the primary 40 MHz subchannel (i.e., the nonprimary 40 MHz subchannel is not ‘idle’ at the AP STA). The subsequent UL data transmission may be performed by the non-AP STA 16 only over the primary 40 MHz subchannel. In this nonlimiting example, a different non-AP STA 16 that may attempt an opportunistic UL data transmission would benefit from detecting both the RTS and CTS frames, e.g., since the different non-AP STA 16 may determine (e.g., would understand) that an opportunistic transmission on the nonprimary 40 MHz subchannel may fail because the AP STA 14 determines that the subchannel is busy. However, in another nonlimiting example, if the RTS and CTS are both sent over the 40 MHz primary subchannel (e.g., the RTS may be transmitted by a non-AP STA 16 having a 40 MHz operating bandwidth), opportunistic UL transmissions over the 40 MHz nonprimary subchannel may have a higher chance of success since the AP may be available and able to receive them. Additionally, a non-AP STA 16 attempting an opportunistic UL transmission in the latter situation may also check the AP’s availability with an opportunistic RTS frame transmission on the nonprimary subchannel before sending UL data opportunistically. In an additional embodiment, a STA 22 detects two control frames that are sent prior to an upcoming data transmission on the primary subchannel of its BSS, and then performs an opportunistic transmission on a nonprimary subchannel concurrent with the data transmission on the primary subchannel.

[0252] To determine that the detected control frame originates from the same BSS, fields such as BSS color field, transmitter address (TA) field, receiver address (RA) field may be read by the detecting STA 22. In addition, the TA and / or RA fields may be used to determine the direction of the upcoming data communication on the primary channel, i.e., uplink (UL) or downlink (DL), e.g., depending on which address is set to the medium access control (MAC) address of the AP STA 14. Further, the STA 22 may perform LBT and follow a dedicated channel access procedure on those resources prior to performing the opportunistic transmission, e.g., to determine that the frequency resources to be used for the opportunistic transmission are idle.

[0253] In a further embodiment, the detected control frame includes an indication to help the detecting STA 22 understand or determine that there may be idle frequency resources available in the at least one unutilized nonprimary subchannel which may be used by the STA 22 to perform opportunistic transmissions. This may be beneficial in situations when the transmitter of the control frame could itself be a potential recipient of an opportunistic transmission. For example, an AP STA 14 transmitting a control frame (e.g., CTS frame) prior to receiving an UL data transmission from a non-AP STA 16 may include such an indication in the control frame, which may be helpful for a different non-AP STA 16 if it tries to perform an opportunistic UL transmission concurrent with the UL data transmission.

[0254] FIG. 9 shows an example opportunistic UL transmission performed on an unutilized nonprimary subchannel during an ongoing UL transmission on the primary subchannel. STA 16b (e.g., STA2) detects an RTS-CTS frame exchange (i.e., RTS to AP 14 on Pl, NP1, and CTS to STA 16a (STA1) on Pl, NP1) corresponding to a UL data transmission (e.g., by STA 16a to AP 14) on the primary subchannel Pl and non-primary subchannel NP1, and subsequently performs an opportunistic UL transmission to the AP 14 on subchannel NP3 concurrent with the ongoing UL transmission on subchannels Pl and NP1. FIG. 9, as a nonlimiting example, illustrates a default ACK frame being sent to STA 16a (e.g., STA1) on subchannels Pl and NP1 along with a delayed ACK frame to STA 16b (e.g., STA2) on subchannel NP3, which may be the case when rules and restrictions are required so that the AP 14 does not have to transmit and receive simultaneously. Alternatively, the opportunistic data transmission from STA 16b (e.g., STA2) to the AP 14 may be padded such that its end time aligns with that of the data transmission from STA 16a (e.g., STA1) to AP 14, thereby ensuring there is no undesired time gap left between the data transmission and its corresponding ACK. Further, LBT may be performed before RTS to AP 14 on Pl, NP1 and / or before data is transmitted to AP 14 by STA 16b on NP3.

[0255] FIG. 10 shows another example opportunistic UL transmission performed on an unutilized nonprimary subchannel during an ongoing peer-to-peer (P2P) transmission on the primary subchannel between two non-AP STAs 16. STA 16a (e.g., STA1) detects an RTS-CTS frame exchange corresponding to a P2P data transmission on the subchannels Pl and NP1 (i.e., RTS to STA 16c (STA3) on Pl, NP1 and CTS to STA 16b (STA2) on Pl, Nl), and subsequently performs an opportunistic UL transmission the AP 14 on subchannel NP3 (i.e., Data to AP on NP3) concurrent with the ongoing P2P transmission on subchannels Pl and NP1 (i.e., Data to STA3 on Pl, NP1). Further, LBT may be performed before RTS to AP 14 on Pl, NP1. Further, LBT may be performed by STA 16b before RTS to STA 16c on Pl, NP1 and / or before data is transmitted to AP 14 by STA 16a on NP3. ACK is transmitted by AP 14 to STA 16a on NP3, and another ACK is transmitted by STA 16c to STA 16b on Pl, Nl.

[0256] Feasibility of detecting control frames to determine the used and unused frequency resources of corresponding data transmissions

[0257] In one or more embodiments, it may be important to detect a control frame that is sent prior to a data transmission since the control frame helps with determining the potential time and frequency resource usage of an upcoming data transmission in advance. An advantage of this advanced knowledge is that it can help a STA 22 to initiate its LBT procedures for accessing an unutilized nonprimary subchannel as soon as the control frame is detected. This may help the STA to win the contention if multiple devices are contending, and also initiate the opportunistic transmission sooner.

[0258] Another aspect is that detection of control frames may be more feasible than that of data transmissions since control frames may be transmitted with higher transmit powers than their corresponding data transmissions. An underlying reason is that data transmissions may feature usage of higher order modulations that may require significant transmit power backoff to ensure acceptable transmit signal quality.

[0259] Additionally, if RTS-CTS frame exchange is used prior to a data transmission and both frames are detected, it can help the STA 22 to determine exactly which frequency resources are being reserved for the data transmission as well as determine which frequency resources are not being reserved. This helps avoid any misinterpretation at the STA 22 due to a hidden node for another STA 22 involved as transmitter or receiver in the data transmission. An example scenario is DL or UL OFDMA, wherein a MU-RTS frame is transmitted by an AP STA 14 over the full reserved communication bandwidth whereas the CTS frames may be transmitted by non-AP STAs 16 only over the subchannels in which they are allocated frequency resources. Thus, if both MU-RTS and CTS frames are detected, it may help determine the frequency resource usage without any confusion. An additional advantage of detecting a control frame that is sent prior to a data transmission on the primary subchannel is that a STA 22 may perform time and / or frequency synchronization of any opportunistic transmission it may attempt on an unutilized nonprimary subchannel, where the synchronization is related to the data transmission on the primary subchannel. This may be used to avoid detrimental interference to the reception of the data transmission on the primary subchannel.

[0260] Embodiments regarding nature of opportunistic transmissions

[0261] In an additional embodiment, the opportunistic transmission may be a control frame transmission. For example, an opportunistic RTS frame transmission may be used by the transmitting STA 22 to determine whether the intended recipient STA 22 is available to receive a subsequent data transmission. Alternatively, the opportunistically transmitted control frame may include buffer status information of data pending at the transmitting STA 22. Alternatively, the opportunistically transmitted control frame may act as a preemption request to pause or terminate the data transmission on the primary subchannel.

[0262] In another embodiment, the opportunistic transmission is a data transmission. An AP 14 managing a BSS may impose restrictions on the type and amount of data that may be communicated in such an opportunistic data transmission.

[0263] In an additional embodiment, the STA 22 performing the opportunistic transmission is a non-AP STA 16, and the opportunistic transmission corresponds to either a UL transmission or a P2P transmission. In an alternative embodiment, the STA 22 performing the opportunistic transmission is an AP STA 14, and the opportunistic transmission corresponds to either a DL transmission or an AP-to-AP transmission.

[0264] In an additional embodiment, the intended recipient STA 22 of the data transmission on the primary subchannel and the opportunistic transmission is the same STA 22, e.g., the AP STA 14, which would imply that the scenario corresponds to an opportunistic UL transmission being performed during another ongoing UL data transmission. In an alternative embodiment, the intended recipient STA 22 of the data transmission on the primary subchannel and the opportunistic transmission are different. For example, the data transmission on the primary subchannel may correspond to a P2P transmission among two non-AP STAs 16, and the opportunistic transmission may be a UL transmission.

[0265] Embodiments regarding selection of appropriate subchannels for opportunistic transmissions In an additional embodiment, if there are multiple unutilized nonprimary subchannels to select from for the opportunistic transmission, one or more of the following criteria may be used (e.g., by STA 22) for the subchannel selection:

[0266] • Random selection among candidate subchannels.

[0267] • Speed of accessing the candidate subchannels, e.g., selecting a subchannel which can be accessed first by following the necessary LBT procedures.

[0268] • Probability of successful transmission, e.g., selecting a subchannel by considering success / failure of previous transmission attempts on the candidate subchannels.

[0269] • Data rate which could be achieved, e.g., selecting a subchannel that may allow for the highest data rate modulation and coding scheme (MCS) to be used.

[0270] • Location of the candidate subchannels compared with the primary subchannel, e.g., selecting a subchannel that is furthest from the primary subchannel in order to cause minimum interference to the data communication on the primary subchannel.

[0271] • Subchannel preference information shared in advance by intended recipient STA 22 of the opportunistic transmission, e.g., which may be based on hardware capabilities and cross-subchannel interference handling capabilities of the intended recipient STA.

[0272] Embodiments regarding signaling, rules, and restrictions for opportunistic transmissions:

[0273] In an additional embodiment, the intended recipient STA 22 of the opportunistic transmission shares information in advance with the STAs 22 it communicates with, the information being about its capabilities to receive an opportunistic transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel. Such information may, for example, be shared by an AP STA 14 with the non-AP STAs 16 in its BSS.

[0274] In an additional embodiment, one or more specific nonprimary subchannels are known beforehand to be permitted for opportunistic transmissions while operating in a BSS. This may, for example, be orchestrated by the AP STA 14 that manages that BSS.

[0275] In an additional embodiment, any opportunistic transmission is permitted to be performed using frequency resources from only one unutilized nonprimary subchannel, e.g., for simplifying the implementation and usage of opportunistic spectrum usage solutions, adhering to current rules and regulations regarding channel access for operating in license-exempt spectrum in certain jurisdictions (for example, in Europe, it is not permitted to change a channel bonding group of subchannels within a duration of less than 1 second when the LBT procedure is such that a random backoff is performed only on the primary subchannel within that group).

[0276] In an additional embodiment, the bandwidths of the primary and nonprimary subchannels are integer multiples of 20 Mega Hertz (MHz). This is the case, for example, in IEEE 802.11 WLANs.

[0277] In an additional embodiment, if the data transmission on the primary subchannel and the opportunistic transmission are based on orthogonal frequency division multiplexing (OFDM) modulation, the OFDM symbol boundaries of the opportunistic transmission are aligned with that of the data transmission on the primary subchannel within the cyclic prefix duration of the data transmission. This helps with reducing potential interference to the data transmission.

[0278] In an additional embodiment, opportunistic data transmissions on nonprimary subchannels are permitted only for a certain data type, e.g., classified based on access category (AC) or traffic identifier (TID). In an additional embodiment, the opportunistic data transmissions on nonprimary subchannels are permitted only in a certain direction, e g., UL, DL, P2P, AP-to-AP.

[0279] Subband full duplex (SBFD) capability to support independent communications on primary and nonprimary subchannels at the same device:

[0280] In subband full duplex (SBFD) operation, the bandwidth within one radio channel is split into non-overlapping sub-bands at the same device, with one or more sub-bands utilized for transmission and the rest for reception.

[0281] SBFD capability at STAs 22 in BSS may be an attractive feature, e.g., a SBFD capable AP STA 14 may be able to communicate independently with multiple non-AP STAs 16 on primary and nonprimary subchannels wherein the communications on the nonprimary subchannels are opportunistic. For example, the communications are such that the AP 14 may have to receive a data transmission on one subchannel while having to transmit an ACK frame on another subchannel. An opportunistic UL data reception on a nonprimary subchannel may be concurrent with an ACK frame transmission from the AP 14 on the primary subchannel, where the AP 114 is SBFD capable.

[0282] In some embodiments, if there is no SBFD capability, then the opportunistic transmissions may be restricted in their timing and duration in scenarios where the intended recipient STA 22 of data transmission on the primary subchannel and the opportunistic transmission on the secondary subchannel is the same. Rules may be used to ensure that the STA 22 does not simultaneously transmit and receive on different subchannels. This may, for example, be ensured by having rules that mandate aligning the start and / or end times of any opportunistic transmissions on nonprimary subchannels with that of the data transmissions on the primary subchannel.

[0283] In some embodiments, the features described herein need to be specified for their standardized usage by devices of different manufacturers. In the IEEE 802.11 WLAN context, there may be clearly identifiable content introduced. For example, rules and procedures regarding opportunistic nonprimary subchannel usage may be specified.

[0284] In some embodiments associated with a first STA 22, a first data transmission may be sent to an STA 22 which is different from a second STA 22. A first control frame is sent by a STA 22 that may be different from the second STA 22 and is always different from the first STA 22. A second control frame is sent by a STA 22 which may be different from the second STA 22 (or may be the same) and is always different from the first STA 22. Further, the same STA 22 may send the first and second control frame.

[0285] In some other embodiments, a first STA 22 is a transmitter of a second (opportunistic) transmission, and a second STA 22 is its receiver. Thus, not only may the second STA 22 send a first control frame, but any STA 22 of the plurality of STAs 22 which is not the first STA 22 may also send a control frame (e.g., first control frame).

[0286] In some embodiments, idle frequency resources are used for a second, (opportunistic) transmission, and the second STA 22 is a receiver.

[0287] In some other embodiments, a first control frame and a second control frame may be transmitted by the same or different STA 22.

[0288] NPCA during intra-BSS traffic on primary channel

[0289] An STA 22 in a BSS may perform opportunistic transmissions using unutilized and idle nonprimary subchannels in the BSS when the primary subchannel is busy due to transmissions within the same BSS. The spectrum wastage that may arise within a BSS due to, for example, a mismatch in operating bandwidths of AP STAs and non-AP STAs may be managed. FIG. 11 illustrates features associated with such opportunistic transmissions. Two opportunistic TXOPs are illustrated, which can be undertaken by performing NPCA during an ongoing TXOP within the same BSS. The NPCA operation during intra-BSS traffic on the primary subchannel results in two simultaneously ongoing transmissions within the same BSS, each of which could be an UL or a DL or a peer-to- peer transmission. In one embodiment, AP STA 14 may be configured to indicate (i.e., transmit an indication) a target receive power for an opportunistic NPCA based transmission over a nonprimary subchannel, which may occur simultaneously with a regular non-NPCA based transmission on the primary subchannel. The AP STA 14 may include such an indication in a transmission sent over the primary subchannel.

[0290] As a non-limiting example, an AP STA 14 may transmit a control frame such as a trigger frame over the primary subchannel to trigger an UL transmission over the primary subchannel, and include a target receive power indication corresponding to a different NPCA based UL transmission that may be received by the AP STA concurrently over the nonprimary subchannel. By doing so, the AP STA 14 may ensure that both UL transmissions would fit within the supported dynamic range of its receiver. Correspondingly, in an embodiment, the indication is transmitted in a control frame such as a Request to send (RTS) frame, multi-user (MU)-RTS frame, clear to send (CTS) frame, CTS-to-self frame, CTS-to-AP frame, trigger frame, etc. In another embodiment, the indication is transmitted by the AP STA 14 in a management frame such as a beacon frame.

[0291] In another embodiment, the indicated target receive power represents either a maximum supported receive power at the AP STA 14 for the opportunistic NPCA based transmission, or a minimum supported receive power at the AP STA 14 for the opportunistic NPCA based transmission. In an additional embodiment, the AP STA 14 indicates a supported range of receive power with respect to the indicated target receive power. These embodiments provide flexibility at the AP STA 14 for providing the indication, and the AP STA 14 may leverage them based on its reception capabilities such as the supported dynamic range during analog to digital conversion.

[0292] The following are some example scenarios of usage of these embodiments Case 1 : TXOP initiated by an AP STA for triggering UL transmission FIG. 12 illustrates the case when a TXOP is initiated by an AP STA 14 for triggering a UL transmission. The AP STA 14 may include the target receive power indication corresponding to a NPCA based UL transmission in the trigger frame sent on the primary 80 MHz channel.

[0293] As a non-limiting example, the following steps may be performed in this Case 1 :

[0294] • AP STA 14 sends a trigger frame on the primary subchannel, which includes an indication of an UL target receive power for any potential NPCA based transmission. o If it is multi-user triggered UL (e.g., as in UL OFDMA) on the primary subchannel, the indicated UL target receive power for NPCA subchannel can be same as UL target receive power for a scheduled non-AP STA 16 on the primary subchannel. This may have already been indicated in an UL OFDMA trigger frame, and thus a separate indication may be avoided for the NPCA subchannel. o Alternatively, if it is single-user triggered UL on the primary subchannel, the AP STA 14 specifically indicates UL target receive power for NPCA subchannel. There is not any UL target receive power indication in single-user triggered UL operation, for example, as specified in the IEEE 802.1 Ibe amendment.

[0295] • A non-AP STA 16 wanting to perform NPCA based transmission detects the trigger frame on the primary subchannel, reads the relevant info from the trigger frame (e.g., to understand NPCA possibility, UL target receive power), switches to NPCA subchannel, and attempts to undertake NPCA based transmission.

[0296] Case 2: TXOP initiated by a non-AP STA for UL transmission

[0297] FIG. 13 illustrates the case when a TXOP is initiated by a non-AP STA 16 for performing a UL transmission. The AP STA 14 may include the target receive power indication corresponding to a NPCA based UL transmission in the CTS frame sent on the primary 80 MHz channel.

[0298] As a non-limiting example, the following steps may be performed in Case 2:

[0299] • AP STA 14 mandates RTS-CTS frame exchange before undertaking UL data transmissions.

[0300] • Non-AP STA 16 initiates TXOP on the primary subchannel with a RTS frame.

[0301] • In the corresponding CTS frame, AP STA 14 indicates an UL target receive power for any potential NPCA based transmission.

[0302] • A non-AP STA 16 wanting to perform NPCA based transmission detects the CTS frame on the primary subchannel, reads the relevant info from the CTS frame (e.g., to understand NPCA possibility, UL target receive power), switches to NPCA subchannel, and attempts to undertake NPCA based transmission.

[0303] Case 3: TXOP initiated by an AP STA for DL transmission FIG. 14 illustrates the case when a TXOP is initiated by an AP STA 14 for performing a DL transmission. The AP STA 14 may include the target receive power indication corresponding to a NPCA based UL transmission in the CTS-to-self frame sent on the primary 80 MHz channel. As a non-limiting example, the following steps may be performed in case 3 :

[0304] • AP STA 14 sends an initial control frame such as a CTS-to-self frame on the primary subchannel, which includes an indication of an UL target receive power for any potential NPCA based transmission.

[0305] • A non-AP STA 16 wanting to perform NPCA based transmission detects the CTS-to-self frame on the primary subchannel, reads the relevant info from the CTS-to-self frame (e.g., to understand NPCA possibility, UL target receive power), switches to NPCA subchannel, and attempts to undertake NPCA based transmission.

[0306] • Thus, the AP STA 14 may transmit a DL transmission on the primary subchannel and simultaneously receive an NPCA based UL transmission on a nonprimary subchannel. In some embodiments, this case may require a selfinterference suppression and / or cancellation capability at the AP STA 14, and the AP STA 14 may be configured to perform the self-interference suppression and / or cancellation.

[0307] One or more embodiments may be specified for their standardized usage by devices of different manufacturers. In the IEEE 802.11 WLAN context, there may be clearly identifiable content introduced in a future amendment. For example, rules and procedures regarding indication of a target receive power for receiving an opportunistic NPCA based transmission may be specified.

[0308] The following is a list of nonlimiting embodiments.

[0309] Embodiment 1. A method for wireless communications by STAs 22 in a BSS, where the BSS is characterized by an AP STA 14 communicating with multiple non- AP STAs 16 using an operating channel that comprises one primary subchannel and at least one nonprimary subchannel. The method includes the following steps:

[0310] (1) A first STA 22 in the BSS detecting a control frame transmitted by a second STA 22 belonging to the same BSS, the control frame comprising information regarding frequency resource usage of an upcoming data transmission;

[0311] (2) Based on the information in the control frame, the first STA 22 determining that the data transmission will utilize frequency resources from the primary subchannel and will not utilize frequency resources from at least one nonprimary subchannel; and

[0312] (3) The first STA 22 performing an opportunistic transmission concurrently with the data transmission and using idle frequency resources from at least one unutilized nonprimary subchannel.

[0313] Embodiment 2. As Embodiment 1, where the first STA 22 detects an additional control frame that is transmitted by a third STA 22 belonging to the same BSS, the additional control frame being detected either immediately before or immediately after detecting the control frame in Step (1), and the additional control frame also comprising information regarding frequency resource usage of the same upcoming data transmission.

[0314] Embodiment 3. As Embodiment 1 or 2, where the opportunistic transmission is completed within an estimated duration of the data transmission.

[0315] Embodiment 4. As Embodiment 3, where the estimated duration is computed based on information contained in the detected control frame.

[0316] Embodiment 5. As any of Embodiments 1-4, where the opportunistic transmission is a control frame transmission.

[0317] Embodiment 6. As Embodiment 5, where the control frame is an RTS frame.

[0318] Embodiment 7. As Embodiment 5, where the control frame comprises buffer status information of data pending at the first STA.

[0319] Embodiment 8. As Embodiment 5, where the control frame is a preemption request to pause or terminate the data transmission on the primary subchannel.

[0320] Embodiment 9. As any of Embodiments 1-4, where the opportunistic transmission is a data transmission.

[0321] Embodiment 10. As Embodiment 9, where the opportunistic data transmission is permitted only for a certain data type, e.g., classified based on access category (AC) or traffic identifier (TID).

[0322] Embodiment 11. As any of Embodiments 1-10, where the first STA 22 is a non-AP STA 16, and the opportunistic transmission corresponds to either an UL transmission or a P2P transmission.

[0323] Embodiment 12. As any of Embodiments 1-10, where the first STA 22 is an AP STA 14, and the opportunistic transmission corresponds to either a DL transmission or an AP-to-AP transmission.

[0324] Embodiment 13. As any of Embodiments 1-12, where the opportunistic transmission is permitted only in a certain direction, e.g., UL, DL, P2P, AP-to-AP. Embodiment 14. As any of Embodiments 1-13, where the intended recipient STA 22 of the data transmission on the primary subchannel and the opportunistic transmission is the same STA 22.

[0325] Embodiment 15. As Embodiment 14, where the same STA 22 is the AP STA 14.

[0326] Embodiment 16. As any of Embodiments 1-13, where the intended recipient STA 22 of the data transmission on the primary subchannel and the opportunistic transmission are different.

[0327] Embodiment 17. As any of Embodiments 1-16, where the intended recipient STA 22 of the opportunistic transmission shares information in advance with the first STA 22 regarding its capabilities to receive an opportunistic transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

[0328] Embodiment 18. As any of Embodiments 1-17, where if the first STA 22 has multiple unutilized nonprimary subchannels to select from for the opportunistic transmission, it follows one or more considerations out of the following for the subchannel selection:

[0329] (1) Random selection among candidate subchannels,

[0330] (2) Speed of accessing the candidate subchannels,

[0331] (3) Probability of successful transmission,

[0332] (4) Data rate which could be achieved,

[0333] (5) Location of the candidate subchannels compared with the primary subchannel,

[0334] (6) Subchannel preference information shared in advance by intended recipient STA of the opportunistic transmission.

[0335] Embodiment 19. As any of Embodiments 1-18, where one or more specific nonprimary subchannels are known beforehand to be permitted for opportunistic transmissions by the first STA 22 while operating in the BSS.

[0336] Embodiment 20. As any of Embodiments 1-19, where the first STA 22 is permitted to use frequency resources from only one unutilized nonprimary subchannel for the opportunistic transmission.

[0337] Embodiment 21. As any of Embodiments 1-20, where the bandwidths of the primary and nonprimary subchannels are integer multiples of 20 MHz. Embodiment 22. As any of Embodiments 1-21, where if the data transmission on the primary subchannel and the opportunistic transmission are based on OFDM modulation, the first STA 22 aligns the OFDM symbol boundaries of the opportunistic transmission with that of the data transmission on the primary subchannel within the cyclic prefix duration of the data transmission.

[0338] Embodiment 23. As any of Embodiments 1-22, where the detected control frame is one of the following:

[0339] (1) RTS frame,

[0340] (2) MU-RTS frame,

[0341] (3) CTS frame,

[0342] (4) CTS-to-self frame,

[0343] (5) CTS-to-AP frame,

[0344] (6) Trigger frame.

[0345] Embodiment 24. As any of Embodiments 1-23, where the detected control frame includes an indication to help the first STA 22 understand that there may be idle frequency resources available in the at least one unutilized nonprimary subchannel which could be used by the first STA 22 to perform opportunistic transmissions.

[0346] Embodiment 25. A method for wireless communications in a basic service set (BSS), the BSS comprising at least an access point (AP) station (STA) 14 and a non-AP STA 16, the BSS operating using a channel that includes at least a primary subchannel and a nonprimary subchannel, the method being applicable or implemented at the AP STA 14, the method comprising:

[0347] (1) Transmitting a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel; and

[0348] (2) Including an indication in the first transmission, the indication indicating a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA 14 using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel.

[0349] Embodiment 26. The method of Embodiment 25, where the AP STA 14 receives the second transmission using the second set of frequency resources simultaneously during an ongoing third transmission over the primary subchannel, the second transmission being received based on the indicated target receive power. Embodiment 27. The method of Embodiment 26, where the third transmission is an uplink (UL) transmission within the BSS, i.e., sent to the AP STA 14 by a non-AP STA 16 within the BSS.

[0350] Embodiment 28. The method of Embodiment 27, where the AP STA 14 receives both the second and the third transmissions based on the indicated target receive power.

[0351] Embodiment 29. The method of Embodiment 26, where the third transmission is a downlink (DL) transmission within the BSS, i.e., sent by the AP STA 14 to a non-AP STA 16 within the BSS.

[0352] Embodiment 30. The method of any one of Embodiments 25-29, where the indicated target receive power represents one of a maximum supported receive power at the AP STA 14 for the second transmission and a minimum supported receive power at the AP STA 14 for the second transmission.

[0353] Embodiment 31. The method of any one of Embodiments 25-30, where the AP STA 14 includes a further indication in the first transmission, the further indication indicating a supported range of receive power for the second transmission with respect to the indicated target receive power.

[0354] Embodiment 32. The method of any one of Embodiments 25-31, where the first transmission is a control frame transmission.

[0355] Embodiment 33. The method of Embodiment 32, where the control frame is one of: a request to send (RTS) frame; a multi-user (MU)-RTS frame; a clear to send (CTS) frame; a CTS-to-self frame; a CTS-to-AP frame; and a trigger frame.

[0356] Embodiment 34. The method of any one of Embodiments 25-31, where the first transmission is a management frame transmission.

[0357] Embodiment 35. The method of Embodiment 34, where the management frame is a beacon frame.

[0358] Embodiment 36. A method for wireless communications in a basic service set (BSS), the BSS comprising at least an access point (AP) station (STA) 14 and a non-AP STA 16, the BSS operating using a channel that includes at least a primary subchannel and a nonprimary subchannel, the method being applicable or implemented at the non-AP STA 16, the method comprising:

[0359] (1) Receiving a first transmission using a first set of frequency resources that include the primary subchannel and do not include the nonprimary subchannel;

[0360] (2) The first transmission including an indication indicating a target receive power at the AP STA 14 for a second transmission that can be received by the AP STA 14 using a second set of frequency resources that include the nonprimary subchannel and do not include the primary subchannel;

[0361] (3) Based on the indication in the first transmission, determining a transmit power setting for the second transmission to be transmitted to the AP STA using the second set of frequency resources; and

[0362] (4) Transmitting the second transmission to the AP STA 14 using the determined transmit power, the second transmission being transmitted simultaneously during an ongoing third transmission over the primary subchannel.

[0363] As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and / or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and / or functionality described herein may be performed by, and / or associated to, a corresponding module, which may be implemented in software and / or firmware and / or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.

[0364] Some embodiments are described herein with reference to flowchart illustrations and / or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0365] These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function / act specified in the flowchart and / or block diagram block or blocks.

[0366] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0367] It is to be understood that the functions / acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

[0368] Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and / or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings and following claims.

Claims

54Claims:

1. A method for wireless communications by a plurality of stations, STAs, (22) in a basic service set, BSS, the BSS being characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels, the plurality of STAs (22) comprising a first STA (22) and a second STA (22), the method being implemented in the first STA (22) and comprising: detecting (SI 00) a first control frame transmitted by at least one STA (22) of the plurality of STAs (22), the at least one STA (22) being different from the first STA (22), the first control frame comprising first information regarding frequency resource usage of a first data transmission; based on the first information in the first control frame, determining (SI 02) that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels; and performing (SI 04) a second transmission to the second STA (22) concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels.

2. The method of Claim 1, wherein the method further includes: detecting a second control frame that is transmitted by at least one STA (22) of the plurality of STAs (22), the at least one STA (22) being different from the first STA (22), the second control frame being detected either within a first predetermined time before or a second predetermined time after detecting the first control frame, the second control frame comprising second information regarding frequency resource usage of the first data transmission.

3. The method of any one of Claims 1 and 2, wherein the second transmission is completed within an estimated duration of the first data transmission.

4. The method of Claim 3, wherein the estimated duration is based on either the first information or the second information or both.

555. The method of any one of Claims 1-4, wherein the second transmission is a control frame transmission.

6. The method of Claim 5, wherein the control frame transmission one of: is a request to send, RTS, frame; comprises buffer status information of data pending at the first STA (22); and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

7. The method of any one of Claims 1-4, wherein the second transmission is a second data transmission.

8. The method of Claim 7, wherein the second data transmission is permitted only for a predetermined data type.

9. The method of any one of Claims 1-8, wherein one of: the first STA (22) is a non-access point station, non-AP STA, (16) and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and the first STA (22) is an access point station, AP STA, (14) and the second transmission corresponds to either a downlink transmission or an AP-to-AP transmission.

10. The method of any one of Claims 1-9, wherein one or both of: the second transmission is permitted only in a predetermined communication direction; and the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

11. The method of any one of Claims 1-10, wherein an intended recipient STA (22) of the first data transmission on the primary subchannel is the second STA (22).

12. The method of Claim 11, wherein the second STA (22) is an access point station, AP STA (14).5613. The method of any one of Claims 1-10, wherein an intended recipient STA (22) of the first data transmission on the primary subchannel is different from the second STA (22).

14. The method of any one of Claims 1-13, wherein the second STA (22) shares information in advance of the second transmission with the first STA (22) regarding capabilities of the second STA (22) to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

15. The method of any one of Claims 1-14, wherein if the first STA (22) has multiple unutilized nonprimary subchannels to select from for the second transmission, the method further includes performing subchannel selection based on one or more of: a random selection among candidate subchannels; a speed of accessing the candidate subchannels; a probability of successful transmission; a potential achievable data rate; a location of the candidate subchannels compared with the primary subchannel; and subchannel preference information shared in advance by the second STA (22) for the second transmission.

16. The method of any one of Claims 1-15, wherein one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA (22) while operating in the BSS.

17. The method of any one of Claims 1-16, wherein the first STA (22) is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission.

18. The method of any one of Claims 1-17, wherein one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.5719. The method of any one of Claims 1-18, wherein the method further includes: if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing, OFDM, modulation, aligning OFDM symbol boundaries of the second transmission with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission.

20. The method of any one of Claims 2-19, wherein the detected first or second control frame is one of: a request to send, RTS, frame; a multi-user RTS, MU-RTS, frame; a clear to send, CTS, frame; a CTS-to-self frame; a CTS-to-AP frame; and a trigger frame.

21. The method of any one of Claims 2-20, wherein the detected first or second control frame includes a first indication, and the method further includes: determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, the one or more idle frequency resources being usable by the first STA (22) to perform second transmissions.

22. The method of any one of Claims 1-21, wherein the first STA (22) is a non- access point station, non-AP STA, (16) the second STA (22) is an access point station, AP STA, (14) the first control frame is transmitted by the AP STA (14) using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels, the first control frame including a second indication indicating a target receive power at the AP STA (14) for the second transmission, the second transmission being receivable by the AP STA (14) using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel, the method further including:based on the second indication in the first control frame, determining a transmit power setting for the second transmission to be transmitted to the AP STA (14); and using the determined transmit power setting for the second transmission to the AP STA (14).

23. The method of Claim 22, wherein the first data transmission is an uplink transmission within the BSS.

24. The method of Claims 23, wherein both of the second transmission and the first data transmission are received at the AP STA (14) based on the indicated target receive power.

25. The method of Claim 22, wherein the first data transmission is a downlink transmission within the BSS.

26. The method of any one of Claims 22-25, wherein the indicated target receive power represents one of a maximum supported receive power at the AP STA (14) for the second transmission; and a minimum supported receive power at the AP STA (14) for the second transmission.

27. The method of any one of Claims 22-26, wherein the first control frame includes a third indication, the third indication indicating a supported range of receive power for the second transmission with respect to the indicated target receive power.

28. A first station, STA, (22) of a plurality of STAs (22), the plurality of STAs (22) being in a basic service set, BSS, the BSS being characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels, the plurality of STAs (22) comprising the first STA (22) and a second STA (22), the first STA (22) being configured to: detect a first control frame transmitted by at least one STA (22) of the plurality of STAs (22), the at least one STA (22) being different from the first STA (22), the firstcontrol frame comprising first information regarding frequency resource usage of a first data transmission; based on the first information in the first control frame, determine that the first data transmission will utilize one or more frequency resources from the primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels; perform a second transmission to the second STA (22) concurrently with the first data transmission, using for the second transmission one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels.

29. The first STA (22) of Claim 28, wherein the first STA (22) is configured to perform one or more of the steps of any one of Claims 2-27.

30. A method for wireless communications by a plurality of stations, STAs, (22) in a basic service set, BSS, the BSS being characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels, the plurality of STAs (22) comprising a first STA (22) and a second STA (22), the method being implemented in the second STA (22) and comprising: receiving (SI 06), from the first STA (22), a second transmission, the second transmission being performed concurrently with a first data transmission, the first data transmission being associated with a first control frame, the first control frame comprising first information regarding frequency resource usage of the first data transmission, the first information in the first control frame informing that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from one or more nonprimary subchannels, wherein one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels are used for the second transmission.

31. The method of Claim 30, wherein a second control frame is transmitted by at least one STA (22) of the plurality of STAs (22), the at least one STA (22) being different from the first STA (22), the second control frame being detected either within a first predetermined time before or a second predetermined time after detecting the firstcontrol frame, the second control frame comprising second information regarding frequency resource usage of the first data transmission.

32. The method of any one of Claims 30 and 31, wherein the second transmission is completed within an estimated duration of the first data transmission.

33. The method of Claim 32, wherein the estimated duration is based on either the first information or the second information or both.

34. The method of any one of Claims 30-33, wherein the second transmission is a control frame transmission.

35. The method of Claim 34, wherein the control frame transmission one of: is a request to send, RTS, frame; comprises buffer status information of data pending at the first STA (22); and is a preemption request to pause or terminate the first data transmission on the primary subchannel.

36. The method of any one of Claims 30-33, wherein the second transmission is a second data transmission.

37. The method of Claim 36, wherein the second data transmission is permitted only for a predetermined data type.

38. The method of any one of Claims 30-37, wherein one of: the first STA (22) is a non-access point station, non-AP STA, (16) and the second transmission corresponds to either an uplink transmission or a peer to peer transmission; and the first STA is an access point station, AP STA, (14) and the second transmission corresponds to either a downlink transmission or an AP-to-AP transmission.

39. The method of any one of Claims 30-38, wherein one or both of: the second transmission is permitted only in a predetermined communication direction; and61 the predetermined communication direction is one of uplink, downlink, peer to peer, and AP-to-AP.

40. The method of any one of Claims 30-39, wherein an intended recipient STA (22) of the first data transmission on the primary subchannel is the second STA (22).

41. The method of Claim 40, wherein the second STA (22) is an access point station, AP STA (14).

42. The method of any one of Claims 30-39, wherein an intended recipient STA (22) of the first data transmission on the primary subchannel is different from the second STA (22).

43. The method of any one of Claims 30-42, wherein the second STA (22) shares information in advance of the second transmission with the first STA (22) regarding capabilities of second STA (22) to receive the second transmission on a nonprimary subchannel concurrently with ongoing communications in the BSS on the primary subchannel.

44. The method of any one of Claims 30-43, wherein if the first STA (22) has multiple unutilized nonprimary subchannels to select from for the second transmission, the method further includes performing subchannel selection based on one or more of: a random selection among candidate subchannels; a speed of accessing the candidate subchannels; a probability of successful transmission; a potential achievable data rate; a location of the candidate subchannels compared with the primary subchannel; and subchannel preference information shared in advance by the second STA (22) for the second transmission.

45. The method of any one of Claims 30-44, wherein one or more specific nonprimary subchannels are predetermined to be permitted for second transmissions by the first STA (22) while operating in the BSS.6246. The method of any one of Claims 30-45, wherein the first STA (22) is permitted, by one or both of an access point and a configuration, to use frequency resources from only one unutilized nonprimary subchannel for the second transmission.

47. The method of any one of Claims 30-46, wherein one or more bandwidths of the primary subchannel and the one or more nonprimary subchannels are integer multiples of 20 MHz.

48. The method of any one of Claims 30-47, wherein if the first data transmission on the primary subchannel and the second transmission are based on orthogonal frequency division multiplexing, OFDM, modulation, OFDM symbol boundaries of the second transmission are aligned with OFDM symbol boundaries of the first data transmission within a cyclic prefix duration of the first data transmission.

49. The method of any one of Claims 31-48, wherein the detected first or second control frame is one of: a request to send, RTS, frame; a multi-user RTS, MU-RTS, frame; a clear to send, CTS, frame; a CTS-to-self frame; a CTS-to-AP frame; and a trigger frame.

50. The method of any one of Claims 31-49, wherein the detected first or second control frame includes a first indication, and the method further includes: determining, based on the first indication, if there are one or more idle frequency resources available in one or more unutilized nonprimary subchannels, the one or more idle frequency resources being usable by the first STA (22) to perform second transmissions.

51. The method of any one of Claims 30-50, wherein the first STA (22) is a non-access point station, non-AP STA, (16) the second STA (22) is an access point station, AP STA, (14) and the method further includes:63 transmitting the first control frame using a first set of frequency resources that include the one primary subchannel and do not include any of the one or more nonprimary subchannels, the first control frame including a second indication indicating a target receive power at the AP STA (14) for the second transmission, the second transmission being receivable by the AP STA (14) using a second set of frequency resources that include the one or more nonprimary subchannels and do not include the primary subchannel.

52. The method of Claim 51, wherein the method further includes: receiving, at the AP STA (14), the second transmission using the second set of frequency resources simultaneously with an ongoing first data transmission over the primary subchannel, the second transmission being received based on the indicated target receive power.

53. The method of any one of Claims 51 and 52, wherein the first data transmission is an uplink transmission within the BSS.

54. The method of Claim 53, wherein the method further includes: receiving, at the AP STA (14), both of the second transmission and the first data transmission based on the indicated target receive power.

55. The method of any one of Claims 51 and 52, wherein the first data transmission is a downlink transmission within the BSS.

56. The method of any one of Claims 51-55, wherein the indicated target receive power represents one of: a maximum supported receive power at the AP STA (14) for the second transmission; and a minimum supported receive power at the AP STA (14) for the second transmission.

57. The method of any one of Claims 51-56, wherein a third indication is included in the first control frame, the third indication indicating a supported range of64 receive power for the second transmission with respect to the indicated target receive power.

58. A second station, STA, (22) of a plurality of STAs (22), the plurality of STAs (22) being in a basic service set, BSS, the BSS being characterized by an operating channel that comprises one primary subchannel and one or more nonprimary subchannels, the plurality of STAs (22) comprising a first STA (22) and the second STA (22), the second STA (22) being configured to: receive, from the first STA (22), a second transmission, the second transmission being performed concurrently with a first data transmission, the first data transmission being associated with a first control frame, the first control frame comprising first information regarding frequency resource usage of the first data transmission, the first information in the first control frame informing that the first data transmission will utilize one or more frequency resources from a primary subchannel and will not utilize one or more other frequency resources from the one or more nonprimary subchannels, wherein one or more idle frequency resources from one or more unutilized nonprimary subchannels of the one or more nonprimary subchannels are used for the second transmission.

59. The second STA (22) of Claim 58, wherein the second STA (22) is configured to perform one or more of the steps of any one of Claims 31-57.

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