CN113301574A

CN113301574A - Method and device for middle frequency-division wide-spectrum multiplexing transmission in wireless communication

Info

Publication number: CN113301574A
Application number: CN202110192101.3A
Authority: CN
Inventors: 吕开颖; 刘剑函; 王超群; 石镕豪; 皮尔二世汤姆士艾德华; 易志熹
Original assignee: MediaTek Singapore Pte Ltd
Current assignee: MediaTek Singapore Pte Ltd
Priority date: 2020-02-21
Filing date: 2021-02-19
Publication date: 2021-08-24
Also published as: DE102021102970A1

Abstract

A device detects that a primary channel having an operating bandwidth of a plurality of channel segments is busy, the channel segments including the primary channel and at least one non-primary channel. In response to detecting that the primary channel is busy, the apparatus obtains a transmission opportunity (TXOP) through a first non-primary channel of the at least one non-primary channel. The apparatus then performs a transmission on at least the first non-primary channel during the TXOP.

Description

Method and device for middle frequency-division wide-spectrum multiplexing transmission in wireless communication

Technical Field

The present invention relates generally to wireless communications, and more particularly to transmission of partial bandwidth (bandwidth) spectral reuse in wireless communications.

Background

Unless otherwise indicated herein, the approaches described in this section are not background to the claims set forth below and are not admitted to be prior art by inclusion in this section.

In the context of wireless communications according to one or more Institute of Electrical and Electronics Engineers (IEEE)802.11 standards, such as local area networks (wanns), devices in a contention-based channel access system may access a medium in a wide frequency band, including multiple narrow frequency bands (or channels), by listening to a main channel and transmitting while the main channel is idle. Under a dynamic broadband transmission scheme, a device is allowed to transmit frames on an idle primary channel and one or more non-primary channels. Furthermore, with the puncturing of the primary channel(s) instead of puncturing the primary channel(s), spectrum usage increases when there are radar signals, existing signals, or Overlapping Basic Service Set (OBSS) interference in one or more non-primary channels.

In next generation wireless communication systems, which support wider operating bandwidths (e.g., 320MHz/160+160MHz/240MHz/160+80MHz/160MHz), contention on the primary channel is allowed and contention on the non-primary channel is not allowed. When the main channel is overloaded or busy due to channel contention, no transmission will be allowed to generate an underutilized wideband spectrum. In addition, the conventional apparatus needs to be protected and also needs to consider fairness issues. Therefore, a solution for a wide band transmission scheme is required in wireless communication.

Disclosure of Invention

The following summary is illustrative only and is not intended to be in any way limiting. That is, the following summary is provided to introduce concepts, brightness, benefits and advantages of the novel and non-obvious techniques described herein. Selected embodiments are further described in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

It is an object of the present invention to provide solutions, concepts, references, techniques, methods and arrangements to solve the aforementioned problems. Under various aspects presented herein, transmission of partial-bandwidth spectral multiplexing in wireless communications may be implemented to further increase spectral multiplexing to allow multiple sets of services to share broadband resources. For example, when the primary channel is busy and one or more non-primary channels are idle, the device may be allowed to transmit on unoccupied non-primary channels in the wideband operating channel, thereby improving bandwidth utilization when the primary channel is unavailable.

In one aspect, a method may involve detecting that a primary channel of an operating bandwidth having a plurality of channel segments is busy, a channel segment comprising the primary channel and at least one non-primary channel. The method also involves obtaining a transmission opportunity (TXOP) through a first non-primary channel on the at least one non-primary channel in response to detecting that the primary channel is busy. The method further involves performing a transmission on at least the first non-primary channel during the TXOP.

In another aspect, an apparatus may include a transceiver and a processor coupled to the transceiver. In operation, a processor may be used to perform certain operations. For example, the processor may detect that a primary channel having an operating bandwidth of a plurality of channel segments is busy, the channel segments including the primary channel and at least one non-primary channel. In response to detecting that the primary channel is busy, the processor may obtain a TXOP through a first non-primary channel of the at least one non-primary channel. Further, the processor can perform a transmission on at least the first non-primary channel during the TXOP.

It is worthy to note that although the description provided herein may be described in the context of certain radio access technologies, networks, and network topologies (e.g., WLAN), the proposed concepts, schemes, and any variations/derivations thereof, may be implemented on or by other types of radio access technologies, networks, and network topologies, such as, but not limited to, bluetooth, ZigBee, 5G/New Radio (NR), LTE-Advanced Pro, internet of things (IoT), industrial internet of things (IIoT), and narrowband IoT (NB-IoT). Accordingly, the scope of the invention is not limited to the embodiments described herein.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It will be appreciated that, because some of the elements may be shown out of proportion to the actual embodiment in order to clearly illustrate aspects of the present invention, the drawings are not necessarily drawn to scale.

FIG. 1 illustrates an exemplary network environment in which various solutions and schemes according to the present invention may be implemented.

Fig. 2 shows an exemplary scenario according to the present invention.

Fig. 3 shows an exemplary scenario according to the present invention.

Fig. 4 shows an exemplary scenario according to the present invention.

Fig. 5 shows an exemplary scenario according to the present invention.

Fig. 6 shows an exemplary scenario according to the present invention.

Fig. 7 shows an exemplary scenario according to the present invention.

Fig. 8 shows an exemplary scenario according to the present invention.

Fig. 9 shows an exemplary scenario according to the present invention.

Fig. 10 shows an exemplary scenario according to the present invention.

Fig. 11 shows an exemplary scenario according to the present invention.

Fig. 12 shows an exemplary scenario according to the present invention.

Fig. 13 shows an exemplary scenario according to the present invention.

Fig. 14 shows an exemplary scenario according to the present invention.

Fig. 15 shows an exemplary scenario according to the present invention.

Fig. 16 shows an exemplary scenario according to the present invention.

Fig. 17 shows an exemplary scenario according to the present invention.

Fig. 18 shows an exemplary scenario according to the present invention.

Fig. 19 shows an exemplary scenario according to the present invention.

Fig. 20 shows an exemplary scenario according to the present invention.

Fig. 21 shows an exemplary scenario according to the present invention.

Fig. 22 shows an exemplary scenario according to the present invention.

Fig. 23 shows an exemplary scenario according to the present invention.

Fig. 24 shows an exemplary scenario according to the present invention.

Fig. 25 shows an exemplary scenario according to the present invention.

Fig. 26 shows an exemplary scenario according to the present invention.

Fig. 27 shows a block diagram of an exemplary communication system in accordance with an embodiment of the present invention.

FIG. 28 sets forth a flow chart illustrating an exemplary process according to embodiments of the present invention.

Detailed Description

Specific embodiments and implementations of the claimed subject matter are disclosed herein. However, it is to be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter, which can be embodied in various forms. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided so that this description of the invention is thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following description, well-known features and details of the technology are omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

Embodiments in accordance with the present invention relate to various techniques, methods, schemes and/or solutions relating to broadband transmission schemes in wireless communications. Some of the possible solutions according to the invention can be implemented individually or jointly. That is, while these possible solutions may be described separately below, two or more of these possible solutions may be implemented in one combination or other combinations.

In the present invention, it is assumed that a Basic Service Set (BSS) is configured with 320MHz or 160MHz operation bandwidth, a first Access Point (AP) of the BSS operates in 320MHz bandwidth and a non-AP device belonging to the BSS supports operation bandwidth of 320MHz, 160+160MHz, 240MHz, 160+80MHz, 160MHz, 80+80MHz, or 80 MHz. Also assuming that Overlapping Basic Service Sets (OBSSs) operate on 80MHz, 160MHz, or 320MHz bandwidths, the BSS and the OBSS have the same or different primary 20MHz channels for channel contention. Further, in the present invention, the term "primary channel" refers to a 20MHz channel that allows medium access (medium access) through channel contention, and the term "non-primary channel" refers to a 20MHz channel that is not a primary channel in a wide band operating bandwidth. Furthermore, the term "channel segment" refers to a set of 20MHz channels (e.g., in a 40MHz, 80MHz, 160MHz, or 240MHz bandwidth), and belonging to a "primary channel segment" refers to a set of 20MHz channels that includes a primary 20MHz channel. It is noted that herein an Access Point (AP) or AP Station (STA) is interchangeably referred to as an "AP" and "non-AP-STA" is interchangeably referred to as a STA. The term "STA" is a generic name used to refer to "non-AP STA" or "AP STA".

FIG. 1 illustrates an example network environment 100 in which various solutions and schemes according to this invention may be implemented. Fig. 2-26 show examples of implementations of various proposed schemes in a network environment 100 according to the present invention. Subsequent descriptions of various proposed schemes are provided with reference to fig. 1-26.

Referring to fig. 1, a network environment 100 may involve an STA110 and another STA120 that wirelessly communicate according to one or more IEEE802.11 standards (e.g., IEEE802.11 be). STA110 may be an AP or a non-AP STA. Similarly, STA120 may be an AP or a non-AP STA. Each STA110 and 120 may be associated with or otherwise belong to a BSS 130 having a wide operating bandwidth (e.g., 320MHz or another bandwidth greater than 80 MHz). Under the proposed scheme according to the present invention, STA110 and STA120 may be configured to perform partial bandwidth spectrum multiplexed transmissions in wireless communications according to various proposed schemes described below.

In network environment 100, when frame transmission from an OBSS or other system (not shown) having a signal strength equal to or greater than a certain level is detected, one of STA110 and STA120 as an AP may obtain a partial bandwidth spectrum multiplexing transmission opportunity (PBSR TXOP) on a partial bandwidth of an operating bandwidth. The PBSR TXOP may not include a primary channel or a primary channel segment, and preamble puncturing (puncturing) may be applied in the PBSR TXOP on the idle channel within the operating bandwidth. One or more non-primary channels or channel segments within the operating bandwidth may be allocated to non-AP devices associated with the BSS 130 to camp on and monitor for new transmissions. non-AP devices residing on a particular non-primary channel or channel segment may receive only Downlink (DL) transmissions or be triggered for Uplink (UL) transmissions. In addition, non-AP devices may switch to the primary channel or primary channel segment to contend for the medium.

With respect to a Partial Bandwidth Transmission (PBT) process, when an AP device (e.g., STA110 or STA120) detects a frame transmission from an OBSS or a transmission from another system with a signal strength equal to or greater than a certain level (e.g., -82dBm of a Preamble Detection (PD) threshold, -72dBm of a spatial multiplexing PD threshold, or-62 dBm of an Energy Detection (ED) threshold), the AP may initiate a PBSR without including a primary channel and one or more non-primary channels that detect an OBSS frame transmission or a channel busy state. An AP may operate on a bandwidth that includes a set of channels. The AP may invoke a channel contention backoff (backoff) procedure on the primary channel to access the wireless medium of the primary channel, and once the backoff procedure has started, the AP may suspend the ongoing backoff procedure when frame transmission or channel busy is detected. The AP may initiate a PBSR TXOP on one or more non-primary channels that are idle when the AP detects an OBSS frame with a signal strength equal to or greater than a certain level. The duration of the PBSR period may be set according to the TXOP duration information or PPDU length information in the received OBSS frame.

Prior to initiating the PBSR TXOP, the AP may invoke a PBT fallback procedure or may resume the fallback procedure suspended during the PBSR period. The back-off counter (or timer) may count down every slot time without detecting the medium status. When the backoff counter counts down to 0, the AP may perform medium status detection during a particular time interval before transmission on each non-primary channel, and may initiate a PBSR TXOP on the non-primary channel detected as idle, the duration of the PBSR TXOP may be limited by the TXOP duration or PPDU length information in the received OBSS frame. The preamble puncturing may be applied to non-primary channels that are not idle. After the PBSR TXOP, the suspended fallback process may be resumed or a new fallback process may be invoked on the primary channel.

With respect to PBSR channel segments, an AP device (e.g., STA110 or STA120) may indicate one or more channel segments for PBSR operation. For example, in a 320MHz operating bandwidth having four 80MHz channel segments, each 80MHz channel segment may contain one or more channels, with the primary channel segment comprising the primary 20MHz channels. The AP device may assign a channel segment for the non-AP device to camp on and monitor for transmissions. The non-AP device may negotiate with the AP device for camping and monitoring the channel segment for transmissions. Further, the non-AP device may switch between the primary channel segment and the non-primary channel segment. For example, a non-AP device may switch to a primary channel segment while camped on a non-primary channel segment. The non-AP device may: (1) based on the indication from the AP device; (2) disabling trigger-based UL transmission by instructing the AP device, and/or (3) an indication announced by a channel segment switch. Further, while camped on the primary channel segment, the non-AP device may instruct it to switch to the non-primary channel segment. The non-AP device may enable the AP device to trigger UL transmissions by signaling and/or request a channel segment switch (e.g., a channel segment switch announcement) by signaling a particular channel segment.

With respect to non-AP device operation in PBSR TXOP, the non-AP device may camp on and monitor a particular channel segment for PBSR operation. For example, the DL frame transmission may be within a particular channel segment allocated to the non-AP device. The control (trigger) frame may include individually addressed resource allocation information to trigger UL transmissions addressed to the non-AP device. In the event that it receives a frame on the channel, the non-AP device may monitor the particular channel segment that is allocated and may update its Network Allocation Vector (NAV). In response to the trigger frame, the non-AP device may perform Clear Channel Assessment (CCA) to sense the status of the medium on the channel on which resources are allocated and/or check the NAV value to decide whether to transmit on the medium. The non-AP devices may use a channel contention mechanism to access the medium on the primary channel and may be triggered by the AP device for UL transmissions when the non-AP devices reside on a non-primary channel segment. When a non-AP device decides to contend for the medium, it may first switch back to the primary channel/primary channel segment. After switching to the primary channel/primary channel segment, the non-AP device may perform Clear Channel Assessment (CCA) until it detects a frame in which the non-AP device may set a NAV or until a period of time expires. In various examples shown and described in fig. 2-5, EDCA-based channel contention may be allowed for AP devices on non-primary channels when the primary channel is unavailable.

Fig. 2 illustrates an exemplary scenario 200 according to the present invention. In scenario 200, an AP device (e.g., STA110 or STA120) operates on 320MHz operating bandwidth and splits the 320MHz bandwidth into four 80MHz channel segments. One of the four 80MHz channel segments is primary 80MHz channel segment 1 and the other three 80MHz channel segments are allocated to different non-AP devices (e.g., STA1, STA2, and STA3) to camp on and monitor transmissions thereon. Each 80MHz channel segment includes four 20MHz channels, one of which is a primary 20MHz channel. When an AP device detects a frame (e.g., PPDU) on the primary 20MHz channel of the primary 80MHz channel segment 1, the AP device may pause its ongoing backoff counter and obtain duration information for OBSS transmissions in the physical layer (PHY) header of the received PPDU. Upon deciding that the received frame is from an OBSS with a signal strength equal to or greater than a certain level (e.g., -62dBm), the AP device may initiate a PBSR TXOP that does not include the primary 80MHz channel segment 1, the duration of the PBSR period being limited by the duration information in the received OBSS PPDU. Prior to initiating the PBSR TXOP, the AP device may invoke a PBT backoff process for a PBT backoff counter to count down per slot without checking the medium state. The PBT backoff counter may be initialized with a random number selected from a balanced distribution in the range of 0 to M, where M is a positive integer (e.g., 10).

When the PBT backoff procedure counts down to 0, the AP device may be performing medium status detection during a particular time interval (e.g., a Point Coordination Function (PCF) inter-frame space (PIFS) interval) prior to transmission on each channel within the 320MHz operating bandwidth except for the channels in primary 80MH channel segment 1. During the PIFS interval after the PBT backoff counter counts down to 0, the AP device may initiate a PBSR TXOP on an idle channel. The preamble puncturing may be applied to non-idle channels. The PBSR TXOP may be limited by duration information of OBSS transmission in the received OBSS PPDU. non-AP STA1, STA2, and STA3 may monitor 80MHz channel segments 2, 3, and 4, respectively, and may receive PPDUs transmitted on these channel segments. Each STA1, STA2, and STA3 may respond with a Block Acknowledgement (BA) in response to the respective PPDU received. After the end of the PBSR TXOP, the suspended fallback procedure may be resumed on the primary channel.

Fig. 3 shows an exemplary scenario 300 according to the present invention. In scenario 300, an AP device (e.g., STA110 or STA120) may initiate a PBSR TXOP to trigger UL transmissions from non-AP devices. The non-AP STA1, STA2, and STA3 may monitor 80MHz channel segments 2, 3, and 4, respectively, and may respond to a trigger frame if allocated resources in the channel are idle. For example, in the case that the STA's bandwidth is less than or equal to 80MHz, the resource allocation of non-AP STA1, STA2, and STA3 may be within monitored 80MHz channel segments 2, 3, and 4, respectively. In the case that the bandwidth of the STA is greater than 80MHz, the resource allocation of the non-AP STA1, STA2, and STA3 may not be limited to the respective monitored channel segments. In the example shown in fig. 3, each non-AP STA1, STA2, and STA3 may receive triggers accordingly, and each STA1, STA2, and STA3 may transmit a trigger-based (TB) PPDU and receive a BA from an AP device.

Fig. 4 shows an exemplary scenario 400 according to the present invention. In scenario 400, an AP device (e.g., ST 110 or STA120) may initiate a PBSR TXOP after the end of the received OBSS PPDU. The AP device may obtain duration information (e.g., TXOP duration of OBSS TXOP) in a media access control layer (MAC) header of the OBSS PPDU, and the AP device may invoke the PBT fallback procedure after the OBSS PPDU ends. After the PBT backoff procedure counts down to 0, the AP device may perform medium status detection during a particular time interval (e.g., PIFS interval) prior to transmission on each channel within the 320MHz operating bandwidth except for the channel in primary 80MHz channel segment 1. The PBSR TXOP may be limited by the TXOP duration of the OBSS TXOP. In the example shown in fig. 4, after the OBSS PPDU ends, the AP device may transmit the PPDU on a free channel in the channel segment monitored by STA1, STA2, and STA 3. Each STA1, STA2, and STA3 may respond with a BA in response to receiving the respective PPDU.

Fig. 5 shows an exemplary scenario 500 according to the present invention. In scenario 500, after the received OBSS PPDU ends, the AP device (e.g., STA110 or STA120) may initiate a PBSR TXOP to trigger UL transmissions from non-AP devices. The AP device may obtain a TXOP duration of the OBSS TXOP in a MAC header of the received OBSS PPDU, and after the received OBSS PPDU ends, the AP device may invoke a PBT fallback procedure. non-AP STA1, STA2, and STA3 may monitor 80MHz channel segments 2, 3, and 4, respectively, and may respond to a trigger frame if the allocated resources of the channel are idle. For example, in the case that the bandwidth of the STA is less than or equal to 80MHz, the resource allocation of the non-AP STA1, STA2, and STA3 may be within the monitored 80MHz channel segment, respectively. In the case that the bandwidth of the STA is greater than 80MHz, the resource allocation of the non-AP STA1, STA2, and STA3 may not be limited to the respective monitored channel segments. In the example shown in fig. 5, each non-AP STA1, STA2, and STA3 may receive respective triggers accordingly, and each STA1, STA2, and STA3 may transmit a trigger-based PPDU and receive a BA from an AP device.

Under the proposed scheme according to the present invention, to support PBSR-based EDCA, an apparatus may maintain two fallback functional states, a first fallback functional state on a primary channel and a second fallback functional state on one or more selected non-primary channels. Under the proposed scheme, a device performing EDCA on a primary channel may suspend operation of its EDCA function (EDCAF) when the primary channel is busy, and the device may store a value of each backoff parameter (e.g., backoff count, contention window (CW [ AC ])), quality of service (QoS) STA retry count (QSRC [ AC ]), etc.) as a first backoff function state. To obtain PBSR TXOPs on non-primary channels, the EDCAF of the apparatus may invoke a new PBT fallback procedure or resume the first fallback procedure as a PBT fallback for accessing the wireless medium on the selected non-primary channel. In the event that an apparatus has pending MAC Protocol Data Units (MPDUs) on a selected non-primary channel for a target recipient, the EDCAF of the apparatus may invoke a new PBT fallback procedure corresponding to an Access Category (AC) of the pending MPDUs on the selected non-primary channel.

Under the proposed scheme, the PBT fallback procedure may follow the EDCA parameters and rules specific to the PBSR TXOP. For example, the EDCA parameters for PBSR TXOP may have a smaller (truncated) contention window. Where PBT fallback is a new fallback procedure, CW can be truncated by a portion of regular CW [ AC ] (e.g., half of regular CW [ AC ] and rounded up to the nearest integer). Where PBT fallback is a continuation of the restored first fallback procedure, the value of the PBT fallback counter may be copied from or truncated by a portion of the value of the first fallback procedure (e.g., half of the value and rounded up to the nearest integer). The EDCA backoff CCA-ED threshold may be adjusted within a certain range (e.g., -82dBM to-62 dBM), for example, less than Δ dB of a conventional CCA-ED threshold. The TXOP limit of the PBSR TXOP may be dynamically limited by a signal-busy status on the primary channel (e.g., a non-0 NAV, a non-0 PPDU length, a non-0 Channel Occupancy Time (COT), or a specific value of PBT).

Under the proposed scheme according to the invention, PBT fallback procedures can be invoked in parallel on multiple selected non-primary channels. In the case where multiple PBT backoff counters are initiated as parallel new PBT backoff processes, each PBT backoff counter may be initialized with a respective (different) random number based on the corresponding CW [ AC ] of pending MPDUs targeted to the selected non-AP channel receivers. Alternatively, each PBT fallback procedure can be initialized with the same random number within a particular CW [ AC ] of the PBSR, or it can be decided by the corresponding CW [ AC ] of the pending MPDUs targeted to the receiver on all selected non-primary channels (e.g., Min (CW [ AC ]), MAX (CW [ AC ]), Average (CW [ AC ])). In the event that the plurality of PBT backoff counters revert from the first backoff process to a concurrent PBT backoff process, each PBT backoff counter may be initialized with a respective (different) random number based on a first backoff functional state of pending MPDUs targeted for the receiver on the selected non-primary channel. Alternatively, each PBT backoff counter may be initialized with the same random number within a particular CW [ AC ] of the PBSR, or it may be determined by the first backoff function state of pending MPDUs targeted to the receiver on all selected non-primary channels (e.g., Min (CW [ AC ]), MAX (CW [ AC ]), Average (CW [ AC ])). Under the proposed scheme, PBT can be performed on the non-primary channel of the acquisition medium once the PBT backoff counter reaches 0. In the case where PIFS is detected to be idle before transmission begins, other non-primary channels within the 80MHz channel segment or segments may be used.

Under the proposed scheme according to the present invention, a PBT fallback procedure can be invoked sequentially on multiple selected non-primary channels within a PBSR TXOP. In the case where multiple PBT backoff counters are sequentially initiated as new PBT backoff processes, each PBT backoff counter or timer may be initialized with a different random number based on the corresponding CW [ AC ] of pending MPDUs targeted to the receiver of the selected non-primary channel. Alternatively, each PBT backoff counter may be initialized with the same random number within a particular CW [ AC ] of the PBSR. In the case where multiple PBT backoff counters are sequentially restored from a first backoff process as a PBT backoff process, each PBT progress counter may be initialized with a different random number based on a first backoff functional state of pending MPDUs targeted to a recipient of a selected non-primary channel. Alternatively, each PBT fallback procedure can be initialized with the same random number within a particular CW [ AC ] of the PBSR. Under the proposed scheme, in case the PBT backoff counter is suspended due to the selected non-primary channel being busy, another PBT backoff may be initiated on another selected non-primary channel. In the event that PIFS is detected to be idle before transmission begins, other non-primary channels within the 80MHz channel segment or segments may be used.

Under the proposed scheme according to the present invention, PBSR TXOP can be sequentially performed on a plurality of selected non-primary channels within a PBSR period. Once the PBSR TXOP on the selected non-primary channel ends, one or more other PBT fallback procedures may be sequentially invoked to obtain another PBSR TXOP. The corresponding PBT backoff counters may be initialized with different random numbers or with the same random number within a particular CW AC of the PBSR based on the corresponding CW AC of pending MPDUs targeted to the receiver of the selected non-primary channel. The corresponding PBT backoff counters may be initialized with different random numbers based on a first backoff function state of pending MPDUs targeted at a receiver of the selected non-primary channel. Alternatively, each PBT backoff timer may be initialized with the same random number within a particular CW [ AC ] of the PBSR.

Fig. 6 shows an exemplary scenario 600 according to the present invention. In scenario 600, a new PBSR EDCA fallback procedure may be initiated on a non-primary channel when there are pending packets/frames for the target recipient on the non-primary channel before the PBSR TXOP begins. For example, the EDCA fallback procedure on the primary channel may be suspended due to the medium status of the channel busy.

Fig. 7 shows an exemplary scenario 700 according to the present invention. In scenario 700, the suspended first EDCA fallback process may be resumed on a non-primary channel before the PBSR TXOP starts. For example, in the case where the first fallback procedure corresponds to an Access Class (AC) of a pending packet/frame of a target recipient on a non-primary channel, the suspended EDAC fallback procedure may be resumed on the non-primary channel.

Fig. 8 shows an exemplary scenario 800 according to the present invention. In scenario 800, one or more PBT fallback procedures may be invoked on one or more non-primary channels before the PBSR TXOP begins. For example, one or more fallback procedures may be invoked in parallel or sequentially, and a PBSR TXOP may be obtained on the non-primary channel that wins the medium as long as any PBT fallback counter reaches 0 first. Furthermore, only one PBSR TXOP is initiated after a successful PBT fallback.

Fig. 9 shows an exemplary scenario 900 according to the present invention. In scenario 900, one or more PBT fallback procedures and a plurality of PBT's may be invoked on one or more non-primary channels within a PBSR cycle. For example, as shown in fig. 9, one or more PBT fallback procedures and TXOPs may be initiated sequentially. Where an apparatus supports multiple concurrent PBT fallback procedures and multiple synchronous or asynchronous TXOPs over different segments in a wide operating frequency bandwidth, one or more PBSR TXOPs can also be initiated in parallel within a PBSR period.

Fig. 10 shows an exemplary scenario 1000 according to the present invention. In scenario 1000, one or more PBT fallback procedures can be invoked on one or more non-primary channels within a PBSR cycle, and once the PBT fallback counter reaches 0, one PBT can be executed. For example, as shown in fig. 10, one or more PBT fallback procedures can be initiated in parallel. Once PBT fallback succeeds, other ongoing PBT fallback may be suspended. Based on the PISF idle detection, PBSR TXOPs can occupy idle non-primary channels, including channels for which PBT fallback is suspended.

Under the proposed scheme according to the present invention, at the end of PBSR TXOP on non-primary channel, EDCA of the apparatus may resume the suspended first fallback procedure or invoke a new fallback procedure on the primary channel. For example, in the case where the previously stored first fallback functional state is empty, or in the case where the first fallback functional state has a value of 0 of the fallback counter, then the EDCAF of the device may invoke a new fallback procedure on the primary channel. Otherwise, the EDCAF of the device may resume the first fallback procedure. Under the proposed scheme, at the end of a PBSR TXOP on a non-primary channel, in case the medium on the primary channel is idle (e.g., in case both virtual carrier sensing (e.g., NAV, PPDU length and/or COT value) and physical CS mechanism (e.g., CCA-ED) indicate that the medium is idle), the first backoff procedure may be resumed to decrement the backoff counter or a new backoff procedure may be initialized to decrement the backoff counter. Further, at the end of a PBSR TXOP on a non-primary channel, the first backoff procedure may resume to decrement the backoff counter or a new backoff procedure may be initiated to decrement the backoff counter when the medium is idle, in the event the medium on the primary channel is busy (e.g., any NAV, PPDU length, and COT value are non-0 or CCA-ED busy).

Under the proposed scheme, an initiation of a synchronization counter (e.g., a synchronization timer) to start a synchronization period may be started immediately at the end of a PBSR TXOP on a non-primary channel. For example, in the case where the virtual CS indicates that the medium on the primary channel is busy after the PBSR TXOP on the non-primary channel ends (e.g., non-0 NAV, non-0 PPDU length, or non-0 COT), the counter may not be initiated. Alternatively, the counter may not be initiated in the case where the physical CS mechanism indicates that the medium is busy after the PBSR TXOP on the non-primary channel ends. Under the proposed scheme, the CCA-ED threshold may be adjusted, e.g., by Δ dB less than the conventional CCA-ED threshold within some range (e.g., -82dBm to-62 dBm), until the PPDU is received with valid TXOP duration information (to set the NAV), or the sync counter expires if the counter is initiated, whichever occurs first.

Fig. 11 shows an exemplary scenario 1100 according to the present invention. In scenario 1100, after the PBSR TXOP ends, the suspended EDCA fallback procedure on the primary channel may be resumed immediately after the PBSR TXOP ends. In scenario 1100, since the medium status is busy, the EDCA fallback procedure on the primary channel may be suspended. Further, a PBSR EDCA fallback procedure on a non-primary channel may be invoked.

Fig. 12 illustrates an exemplary scenario 1200 in accordance with the present invention. In scenario 1200, where a PBT fallback process is suspended due to a busy channel, the suspended EDCA fallback process on the primary channel may be resumed at the end of the TXOP on the primary channel. In scenario 1200, the EDCA fallback procedure on the primary channel may be suspended due to the medium status of the channel busy. Furthermore, the PBSR EDCA fallback procedure on non-primary channels may be invoked or suspended since the channel is busy.

Fig. 13 shows an exemplary scenario 1300 according to the present invention. In scenario 1300, after the PBSR TXOP ends, a new EDCA fallback procedure on the primary channel may be invoked immediately after the PBSR TXOP ends, even though no additional transmissions are currently queued. In scenario 1300, the EDCA fallback procedure on the primary channel may be suspended due to the medium status of the channel busy. Furthermore, during busy times on the primary channel, suspended EDCA fallback procedures may be resumed on non-primary channels.

Fig. 14 illustrates an exemplary scenario 1400 according to the present invention. In scenario 1400, after the PBSR TXOP ends, a new EDCA fallback procedure may be invoked on the primary channel even though there are no additional transmissions that are currently queued. In scenario 1400, when the primary channel is occupied (busy), a PBSR EDCA fallback procedure may be invoked on the non-primary channel.

Under the proposed scheme according to the present invention, at the end of a PBSR TXOP on a non-primary channel, the apparatus with the second backoff counter (PBT backoff counter) may be reset and discard the second backoff functional state. In the event that the PBT fallback process is a newly initiated fallback process, the second fallback functional state may be reset on the selected non-primary channel and the previously stored first fallback functional state may be restored on the primary channel. In the event that the PBT fallback process is a restoration of a first fallback process on the primary channel, the second fallback functional state may be reset on the selected non-primary channel and a previously stored first fallback functional state may be restored on the primary channel. Alternatively, the new fallback functional state may replace the first fallback functional state on the primary channel.

Under the proposed scheme according to the present invention, when the device leaves the primary channel and starts a PBSR cycle on a non-primary channel, the device can always start transmission with a control frame to request acknowledgement of the required channel state on the responding side to obtain and protect PBSR TXOP on the non-primary channel. For example, Request To Send (RTS) and Clear To Send (CTS) exchanges may be used for PBSR TXOP protection. A target recipient residing on a non-primary channel or channel segment may record the virtual channel state of the channel on the corresponding non-primary channel via a Network Allocation Vector (NAV). Once the target receiving device detects that the medium is idle (e.g., NAV is 0 and/or CCA-ED is empty), the receiving device may respond to the received control frame. The PBSR period may be a period in which the primary channel is estimated to be busy. For example, the PBSR period may be decided based on TXOP duration information of ongoing transmissions detected on the primary channel. Alternatively, the PBSR period may be decided based on the length of the PPDU being transmitted detected on the primary channel. Alternatively, the PBSR period may be decided based on the COT of another system. The maximum allowed number of transmissions that begin with a control frame exchange may be specified before the PBSR period expires or the PBSR period mentions the end. Multiple PBT's may be allowed within a PBSR period on the same or different non-primary channels/channel segments.

Fig. 15 shows an exemplary scenario 1500 in accordance with the present invention. In scenario 1500, when the PBT backoff counter reaches 0, a control frame exchange may be initiated to obtain PBSR TXOPs on a non-primary channel. For example, RTS/CTS frame exchanges are necessary for PBSR TXOPs. In addition, multi-user (MU) -RTS/CTS frame exchange is necessary for multi-user TXOP protection.

Under the proposed scheme according to the present invention, when the PBSR period ends on the non-primary channel or the apparatus decides to end the PBSR period early, the apparatus can resume or invoke the fallback procedure on the primary channel and obtain TXOP on the primary channel when the fallback counter reaches 0. Under the proposed scheme, when the channel state of the responding side is idle, the TXOP may be protected by requesting an acknowledgement with a control frame start transmission unless the virtual CS state (NAV) is updated by the received PPDU or expires if a synchronization counter (or synchronization timer) is initiated (whichever occurs first). For example, once the target recipient detects that the medium is idle (e.g., NAV of 0 and/or CCA-ED is idle), it may respond to the received control frame (e.g., an RTS/CTS frame exchange may be used for TXOP protection). A target recipient residing on a primary channel/channel segment may maintain a virtual channel state (NAV) for the primary channel. The maximum number of allowed transmissions to begin with a control frame exchange may be specified before the NAV is updated or the synchronization counter (if any) expires.

Fig. 16 shows an exemplary scenario 1600 according to the present invention. In case 1600, when a device is handed off to the primary channel after the PBT ends, the TXOP initiated by the device on the primary channel may be protected by the control frame exchange unless the NAV is updated or the synchronization counter (if any) expires, whichever occurs first. For example, an RTS/CTS frame exchange is necessary for TXOP protection on the primary channel before the NAV is updated or the synchronization counter expires (if any). In addition, MU-RTS/CTS frame exchange is necessary for multi-user TXOP protection.

Thus, under the proposed scheme for supporting EDCA-based PBT described with respect to fig. 6-16, the apparatus may maintain two fallback functional states, one (first fallback functional state) for the primary channel and the other (second fallback functional state) for the selected non-primary channel. To obtain PBSR TXOPs on non-primary channels, the EDCAF of the apparatus may invoke a new PBT fallback procedure or resume the first fallback procedure as PBT fallback for accessing the wireless medium on the selected non-primary channel. Under the proposed scheme, EDCA parameters for PBT backoff may include, by way of example and not limitation, (1) a Contention Window (CW) truncated by a portion of the normal CW, (2) a PBT backoff counter that is set to an initial value based on the value of the first backoff counter, (3) an EDCA backoff CCA-ED threshold that may be adjusted, and (4) a TXOP limit that may be limited by the state of the primary channel. Further, under the proposed scheme, the PBT fallback procedure can be invoked in parallel or sequentially (sequentially) on multiple selected non-primary channels. Further, under the proposed scheme, at the end of PBSR on non-primary channel, the EDCAF of the apparatus may resume the suspended first fallback procedure or invoke a new fallback procedure on the primary channel. For example, a synchronization timer may be initiated to begin a synchronization period immediately after the PBT ends. Additionally, in the event that the synchronization timer does not expire, the CCA-ED threshold for backoff on the primary channel may be adjusted after PBT unless the PPDU is received before the synchronization timer expires. Further, TXOP protection may be enabled for transmissions on the primary channel in the event that the concurrent timer does not expire, unless a PPDU is received before the synchronization timer expires. TXOP protection may be enabled for PBT (e.g., RTS/CTS frame exchange before PBT).

Fig. 17 illustrates an exemplary scenario 1700 in accordance with the present invention. In scenario 1700, an AP device (e.g., STA110 or STA120) operates on a 320MHz operating bandwidth and splits the 320MHz bandwidth into four 80MHz channel segments. One of the four 80MHz channel segments is labeled as the primary 80MHz channel segment and the other three 80MHz channel segments are labeled 80MHz bandwidth part 1, part 2, and part 3, respectively. Each 80MHz channel segment includes four 20MHz channels, one of which is designated/preconfigured for contention-based channel access. When the AP device detects a frame transmission (e.g., PPDU) from an OBSS (e.g., -62dBm) having a signal strength equal to or greater than a certain level, the AP device may initiate a PBT TXOP at a preconfigured portion of bandwidth. For example, the AP device may invoke a channel contention backoff procedure on the primary channel to access the medium. Further, the AP device may suspend its ongoing backoff process when frame transmission is detected. The AP device may initiate a PBT TXOP at a preconfigured portion of bandwidth when the AP device detects an OBSS frame with a signal strength equal to or greater than a particular level (e.g., -62 dBm). In the present invention, the PBT period refers to a period set by TXOP duration information in a received OBSS frame.

As indicated above, prior to initiating a PBT TXOP, the AP device may involve a PBT fallback procedure on a particular bandwidth portion (e.g., bandwidth portion 4 shown in fig. 17), e.g., using EDCA channel access. A back-off timer corresponding to a back-off procedure may count down based on CCA performance on a pre-configured 20MHz channel for a particular portion of bandwidth. When the back-off timer counts down to 0, the AP device may obtain the PBT TXOP in the bandwidth portion. Notably, preamble puncturing may be applied to non-primary channels that are not idle (e.g., based on PIFS idle detection prior to transmission). Furthermore, under the proposed scheme, PBT TXOP may be limited by TXOP duration information in the received OBSS frames.

Fig. 18 shows an exemplary scenario 1800 according to the present invention. In scenario 1800, an AP device (e.g., STA110 or STA120) operates on a 320MHz operating bandwidth and splits the 320MHz bandwidth into four 80MHz channel segments. One of the four 80MHz channel segments is labeled as the primary 80MHz channel segment and the other three 80MHz channels are labeled as 80MHz bandwidth segment 1, segment 2, and segment 3, respectively. Each 80MHz channel segment contains four 20MHz channels, one of which is preconfigured for contention-based channel access. In scenario 1800, PBT fallback procedures can be invoked in bandwidth part 1 and bandwidth part 2, respectively, with the fallback timer for each fallback procedure being initiated by the same random number or a different randomizer. For example, each fallback procedure may be performed using EDCA channel access. In scenario 1800, the fallback procedure on bandwidth portion 2 may be suspended due to a busy state. Based on CCA conditions on channel 1 of bandwidth part 1 (e.g., channel 1 in fig. 18), the AP device may initiate a PBT TXOP on bandwidth part 1 when the back-off timer on bandwidth part 1 counts down to 0. It is noted that the preamble puncturing may be applied to non-primary channels that are not idle in bandwidth portion 1. Further, in cases where a TXOP period is indicated, the PBT TXOP may be limited by duration information in the received OBSS frame (e.g., PPDU).

It is noted that in a wide bandwidth system with an operating bandwidth of 240MHz, 160+80MHz, 320MHz sitting at 160+160MHz, in the case that most of the user devices only support a narrow bandwidth (such as 80MHz, 160MHz or 80+80MHz), the wide bandwidth may not be fully utilized due to the fact that the channel contention mechanism only operates on the main channel. Under the proposed scheme according to the present invention, a primary channel and one or more secondary channels may be configured in a BSS (e.g., BSS 130). Under the proposed scheme, a 20MHz channel may be designated as a primary channel of a BSS of a certain duration for contention-based channel access (e.g., EDCA) operation. Furthermore, when the primary 20MHz channel is blocked/busy, one or more 20MHz channels of different segments of BSS operating bandwidth may be designated as secondary primary channels for channel access. The secondary primary channels of different channel segments may be designated as primary channels of the BSS for a particular time interval or duration. The AP device may signal when: the secondary primary channel becomes the primary channel and the current primary channel becomes the secondary primary channel.

Under the proposed scheme, the broadband system may apply a dynamic main channel scheme to control channel access. For example, the AP device may specify a particular duration for one primary 20MHz channel for contention-based channel access (EDCA). The AP device may also designate one or more 20MHz channels of different channel segments of BSS operating bandwidth as secondary primary channels for accessing the primary 20MHz channels when they are blocked/busy. The AP device may control and signal the primary channel for different durations in multiple secondary primary 20MHz channels located in different bandwidth portions/segments. non-AP devices residing on the primary 20MHz channel may contend for the channel using EDCA, and non-AP devices associated with the AP device may reside on the secondary primary 20MHz channel of the portion/segment of bandwidth. The AP device controls a channel access mode of a non-AP device residing on a secondary primary 20MHz channel to restrict it from contention-based channel access. For example, the AP device may change the EDCA parameter to a low priority parameter or allow only UL based on a trigger, or the AP device may change an MU-EDCA counter that sets a specific value to disallow EDCA.

Fig. 19 shows an example scenario 1900 of a dynamic primary channel scheme in accordance with the present invention. In scenario 1900, in each interval, a primary 20MHz channel may be designated in an 80MHz portion/segment of bandwidth. Alternatively, only one 20MHz channel may be used for channel contention. In addition, different intervals may have different primary 20MHz channels located in different 80MHz portions/segments of bandwidth. Further, a change in the primary channel may be indicated by the AP device, and the duration of such a transition may also be indicated by the AP device.

With the proposed scheme according to the present invention, one primary channel as well as the secondary primary channel can be used by the AP device for channel access for a certain duration. For example, for a particular duration, a primary 20MHz channel may be designated for channel access and one or more 20MHz channels may be designated as secondary primary channels for channel access during times of primary channel blocking/busy. The secondary primary channel may be located in different portions/segments of the bandwidth. The auxiliary primary channel may become the default primary channel when the AP device signals a switch of the primary channel to the corresponding bandwidth portion/segment. The secondary primary channel may be dynamically accessed by the AP device based on EDCA channel contention when the primary channel is blocked/busy. The AP device may uniformly perform random selection of one or more secondary primary channels when the primary channel is blocked/busy. When selecting a plurality of secondary primary channels for channel access, one secondary primary channel that first falls back to 0 may be used for channel access.

Fig. 20 shows an exemplary scenario 2000 of a dynamic main channel scheme according to the present invention. In scenario 2000, one primary 20MHz channel is designated in an 80MHz portion/segment of bandwidth and multiple 20MHz channels are designated as secondary primary channels in other portions/segments of bandwidth within each interval. In a particular interval, one secondary primary 20MHz channel may be a primary channel in another interval. For example, as shown in fig. 20, the secondary primary 20MHz channel of 80MHz segment 2 in interval 1 may become the primary 20MHz channel of 80MHz segment 2 in interval 2.

Under the proposed scheme according to the present invention, an AP device operating in a wide bandwidth may provide flexible channel access opportunities using a dynamic main channel scheme. The AP device may divide the wide bandwidth into multiple bandwidth portions (or segments) and configure the 20MHz channel as a primary channel or a secondary primary channel for each bandwidth portion, respectively. The AP device may activate a portion of the primary channel for contention-based channel access for a specified duration. For a certain duration, the auxiliary primary channel at other portions of the bandwidth may be used for channel access by the AP device when the primary 20MHz channel is blocked/busy. When the primary channel is blocked/busy, the secondary primary channel may be dynamically accessed based on EDCA channel contention. When the primary channel is blocked/busy, the AP device may select one or more secondary primary channels for channel access. When multiple secondary primary channels are selected for channel access, multiple backoff processes may be performed on the secondary primary channels, and the first process for which the backoff counter reaches 0 may be used for channel access. The secondary primary channel may become the primary channel when the AP device indicates a change of the primary channel to the corresponding portion/segment of bandwidth.

Fig. 21 shows an exemplary scenario 2100 of a dynamic main channel scheme according to the present invention. In scenario 2100, the AP device may select a secondary primary channel for channel access when the primary channel is blocked due to interference. Based on the CCA detection on the selected secondary primary channel, the backoff counter may start counting down. ED detection (e.g., PIFS check before transmission) may be performed on other channels within the bandwidth portion/segment.

Fig. 22 shows an exemplary scenario 2200 of a dynamic main channel scheme according to the present invention. In scenario 2200, the AP device may select a secondary primary channel for channel access when the primary channel is blocked. Based on the CCA detection on the selected secondary primary channel, the backoff counter may start counting down. In the event that the selected secondary primary channel is also blocked, then the AP device may select another secondary primary channel for channel access. In the case where the primary 20MHz channel is not blocked (e.g., NAV equals 0 or physical CS indicates idle), then the AP device may switch back to the primary channel for channel access.

Fig. 23 shows an exemplary scenario 2300 of a dynamic main channel scheme in accordance with the present invention. In scenario 2300, the AP device may select a secondary primary channel for channel access when the primary channel is blocked. Based on the CCA detection on the selected secondary primary channel, the backoff counter may start counting down. ED detection (e.g., PIFS check prior to transmission) may be performed on other channels within multiple bandwidth portions/segments.

Fig. 24 shows an exemplary scenario 2400 of a dynamic main channel scheme according to the present invention. In scenario 2400, when the primary channel is blocked, the AP device may select multiple secondary primary channels for channel access. The EDCA fallback procedure may be performed with an initial value on each selected secondary primary channel. The initial value of each back-off counter may be the same or different. The backoff counter may start counting down based on CCA detection on the selected secondary primary channel, respectively. ED detection (e.g., PIFS check before transmission) may be performed on other channels within the bandwidth portion/segment.

Fig. 25 shows an exemplary scenario 2500 of a dynamic primary channel scheme according to the present invention. In scenario 2500, when the primary channel is blocked, the AP device may select multiple secondary primary channels for channel access. The EDCA fallback procedure may be performed on each selected secondary primary channel with its own initial value. The backoff counter may start counting down based on CCA detection on the plurality of selected secondary primary channels, respectively. In scenario 2500, after the backoff on segment 3 counts down to 0, the backoff on segment 4 may be suspended.

Fig. 26 shows an exemplary scenario 2600 of a dynamic main channel scheme according to the present invention. In scenario 2600, when the primary channel is blocked, the AP device may select multiple secondary primary channels for channel access. The EDCA fallback procedure may be performed on each selected secondary primary channel with its own initial value. The backoff counter may start counting down based on CCA detection on the selected secondary primary channel, respectively. In scenario 2600, after the backoff on segment 3 counts down to 0, the backoff on segment 4 may be suspended. In addition, ED detection (e.g., PIFS check prior to transmission) may be performed on other channels including the secondary primary channel of segment 4.

Thus, under the proposed scheme described above with respect to fig. 19-26, one primary channel and multiple secondary primary channels may be designated for a BSS (e.g., BSS 130) within a time interval or by system information. For example, for a BSS having 320MHz operating bandwidth, the 320MHz bandwidth may be split into four 80MHz bandwidth segments, one 20MHz main channel being assigned for each 80MHz bandwidth segment, the 320MHz operating bandwidth having a total of four main channels. Of the four primary channels, one primary channel may be the designated primary channel for the entire 320MHz bandwidth and the other three primary channels may be auxiliary primary channels. The AP device of the BSS may change the designated primary channel to the secondary primary channel for some time interval or as explicitly indicated.

Furthermore, under the proposed scheme described with respect to fig. 19-26, flexible channel access rules may be applied based on the state of the designated primary channel as well as the secondary primary channel. For example, the AP device may perform EDCA-based channel contention on the currently designated primary channel. When the designated primary channel is blocked/busy, the secondary primary channel in the other 80MHz bandwidth segment may be used for the AP device to perform EDCA-based channel contention. When multiple secondary primary channels are selected for channel access, one or more backoff procedures may be performed on the secondary primary channels. The first of these fallback procedures, with the fallback counter counting down to 0, may be used for channel access. Thus, similar to the non-primary channels described with respect to fig. 2-18, in the examples shown in fig. 19-26, when the primary channel is blocked/busy, the secondary primary channel may be used for channel contention, thereby improving bandwidth utilization when the primary channel is unavailable.

Fig. 27 shows an exemplary system 2700 with at least one exemplary device 2710 and an exemplary device 2720 according to the present disclosure. Each of the devices 2710 and 2720 can perform various functions to implement the schemes, techniques, procedures, and methods for transmission with partial bandwidth spectrum reuse in wireless communications, including the various proposed designs, concepts, schemes, systems, and methods described above and procedures described below. For example, apparatus 2710 may be implemented in one of STA110 or STA120 and apparatus 2720 may be implemented in the other of STA110 or STA120, or vice versa.

Each device 2710 and 2720 may be part of an electronic device, which may be a STA or an AP, such as a portable or mobile device, a wearable device, a wireless communication device, or a computing device. When implemented in a STA, each of the apparatus 2710 and apparatus 2720 may be implemented in a smartphone, a smartwatch, a personal digital assistant, a digital camera, or a computing device such as a tablet, desktop, or laptop computer. Each device 2710 and 2720 may also be part of a machine-type device, which may be an IoT device, such as a stationary or fixed device, a home device, a wired communication device, or a computing device. For example, each device 2710 and device 2720 may be implemented in a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center. When implemented or implemented as a network device, the device 2710 and/or the device 2720 may be implemented in a network node, such as an AP in a WLAN.

In some embodiments, each device 2710 and device 2720 may be implemented in one or more Integrated Circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more Reduced Instruction Set Computing (RISC) processors, or one or more Complex Instruction Set Computing (CISC) processors. In the various aspects described above, each device 2710 and device 2720 may be implemented at or as a STA or an AP. Each device 2710 and 2720 may include at least some of the elements shown in fig. 27, such as processor 2712 and processor 2722, respectively. Each of the device 2710 and the device 2720 further includes one or more other elements (e.g., an internal power source, a display device, and/or a user interface device) not relevant to the aspects of the present invention, and thus such elements of the device 2710 and the device 2720 may not be shown in fig. 27 nor described below for simplicity.

In one aspect, each processor 2712 and processor 2722 may be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more RISC processors, or one or more CISC processors. That is, although the singular term "a processor" is used herein to refer to both the processor 2712 and the processor 2722, each of the processor 2712 and the processor 2722 may include multiple processors in some embodiments and a single processor in other embodiments. On the other hand, each of the processor 2712 and the processor 2722 may be implemented in hardware (optionally firmware) with electronic components including, by way of example and not limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and/or one or more varactors configured and used to achieve certain objectives in accordance with the present invention. In other words, in at least some embodiments, each of processor 2712 and processor 2722 is a dedicated machine specifically designed, arranged, and configured to perform certain tasks including transmission of partial bandwidth spectrum reuse in wireless communications in accordance with various embodiments of the present invention.

In some embodiments, the device 2710 may also include a transceiver 2716 coupled to the processor 2712. The transceiver 2716 may include a transmitter capable of wireless transmission and a receiver capable of wireless reception of data. In some embodiments, the apparatus 2720 may also include a transceiver 2726 coupled to the processor 2722. The transceiver 2726 may include a transmitter capable of wireless transmission and a receiver capable of wireless reception of data.

In some embodiments, the device 2710 may further include a memory 2714 coupled to the processor 2712, which is accessible by the processor 2712 and in which data is stored. In some embodiments, the apparatus 2720 may further include a memory 2724 coupled to the 2722, which is accessible by the processor 2722 and storing data therein. Each of memory 2714 and memory 2724 may comprise a type of Random Access Memory (RAM) such as dynamic RAM (dram), static RAM (sram), transistor RAM (T-RAM), and/or 0 capacitor RAM (Z-RAM). Alternatively, each of memory 2714 and memory 2724 may include one type of read-only memory (ROM), such as shadow ROM, programmable ROM (prom), erasable programmable ROM (eprom), and/or electrically erasable programmable ROM (eeprom). Alternatively, each of memory 2714 and memory 2724 may include a type of non-volatile random access memory (NVRAM), such as flash memory, solid state memory, ferroelectric ram (feram), magnetoresistive ram (mram), and/or phase change memory.

Each device 2710 and 2720 may be communication entities capable of communicating with each other using the scheme proposed according to the present invention. For purposes of illustration and not limitation, a performance description is provided below with device 2710 as one of STA110 and STA120 and device 2720 as the other of STA110 and STA 120. It is noted that although the description of the exemplary embodiments is provided in the context of a WLAN, the same may be implemented in other types of networks.

Under a scheme in accordance with the invention for transmission of partial band spectral multiplexing in wireless communications, processor 2712 of apparatus 2710 may detect, via transceiver 2716, that a primary channel is busy (e.g., by receiving a frame on the primary channel) for an operating bandwidth having a plurality of channel segments, the channel segments including the primary channel and at least one non-primary channel. Further, in response to detecting that the primary channel is busy, processor 2712 may obtain a TXOP (e.g., a PBSR TXOP) over a first non-primary channel of the at least one non-primary channel via transceiver 2716. Further, during a TXOP, processor 2712 may perform transmissions on at least the first non-primary channel via transceiver 2716.

In some embodiments, processor 2712 may perform certain operations when the main channel is detected to be busy. For example, processor 2712 may perform a channel contention backoff contention on the primary channel for access to the medium of the primary channel. Further, in response to detecting that the primary channel is busy, processor 2712 may suspend the fallback procedure.

In some embodiments, processor 2712 may receive frames from transmissions on the primary channel by the OBSS upon detecting that the primary channel is busy. Alternatively, processor 2712 may detect that the signal energy on the primary channel is above a threshold of energy detection.

In some embodiments, processor 2712 may perform additional operations in obtaining a TXOP. For example, processor 2712 may resume a suspended fallback process or initiate a new fallback process such that the fallback counter counts down on the first non-primary channel. Further, processor 2712 can initiate a TXOP on the first non-primary channel in response to the backoff counter counting down to 0 on the first non-primary channel. Further, the medium state of each of the at least one non-primary channel other than the first non-primary channel is determined during a particular time interval prior to the start of the TXOP. The processor 2712 may determine a bandwidth of the TXOP. In some embodiments, the particular time interval may comprise a PIFS interval.

In some embodiments, processor 2712 may execute a fallback process on a first non-primary channel within a selected channel segment upon resuming a suspended fallback process or upon initiating a new fallback process. Alternatively, processor 2712 may perform multiple backoff procedures on multiple non-primary channels of the at least one non-primary channel within the respective channel segment.

In some embodiments, when a TXOP is initiated, processor 2712 may set the duration of the TXOP according to duration information obtained from the duration of the TXOP or PPDU length information transmitted by an OBSS in a received frame. Alternatively, processor 2712 may set the duration of the TXOP to a particular value.

In some embodiments, processor 2712 may perform DL transmissions to at least one non-AP device on at least one non-primary channel while performing transmissions on a first non-primary channel. Or processor 2712 may trigger UL transmission from at least one non-AP device on at least one non-primary channel.

In some embodiments, processor 2712 may perform certain operations in obtaining a TXOP. For example, processor 2712 may maintain a first fall-back functional state for a primary channel and a second fall-back functional state for a first non-primary channel. Further, processor 2712 may perform EDCA backoff on the primary channel. Further, processor 2712 may suspend EDCA backoff on the primary channel upon detecting that the primary channel is busy. Also, the processor 2712 may store values of each of a plurality of backoff parameters for EDCA backoff on the primary channel as a first backoff function state. In this case, the plurality of backoff parameters may include at least a backoff count, a contention window, and a QoS STA retry count.

In some embodiments, the at least one non-primary channel may comprise a plurality of non-primary channels, including the first non-primary channel. In this case, processor 2712 may perform additional operations when obtaining a TXOP. For example, processor 2712 may invoke at least one fallback process by invoking a fallback process for at least one fallback process on a corresponding one of the plurality of non-primary channels. Further, processor 2712 can select a first non-primary channel to initiate a TXOP thereon in response to a respective backoff procedure on the first non-primary channel that first counts down to 0 of the plurality of non-primary channels.

In some embodiments, processor 2712 may invoke at least one fallback process in parallel or sequentially by initiating at least one new fallback process on the primary channel when invoking the at least one fallback process.

In some embodiments, where invoking the at least one fallback process involves resuming a suspended fallback process, the respective fallback counter for each at least one fallback process may be initialized based on the first fallback functional state of the primary channel. In some embodiments, where the invocation of the at least one fallback process involves initializing a new fallback process for the first non-primary channel, the respective fallback counter for each at least one fallback process may be initialized based on the access category. In some embodiments, the second fallback functional state for the first non-primary channel may be reset. In addition, the previously stored first fallback functional state may be restored on the primary channel.

In some embodiments, in obtaining a TXOP, processor 2712 may perform an exchange of RTS and CTS frames prior to any data or management frame transmission within the TXOP.

In some embodiments, after the TXOP, processor 2712 may (1) resume a previous fallback process suspended on the primary channel in response to detecting that the primary channel is busy; or (b) invoke a new fallback procedure on the primary channel.

In some embodiments, after the TXOP, when acquiring the TXOP on the primary channel, processor 2712 may perform an RTS and CTS frame exchange prior to any data or management frame transmission. In some embodiments, in performing the RTS and CTS frame exchange, processor 2712 may perform the RTS and CTS frame exchange in response to at least one of: (1) an unexpired (if any) synchronization timer, and (2) the NAV is not updated by the received PPDU.

In some embodiments, processor 2712 may perform additional operations. For example, for each plurality of channel segments each having a plurality of channels, processor 2712 may designate one of the plurality of channels as a primary channel for the respective channel segment to generate a plurality of primary channels for the plurality of channel segments. Further, processor 2712 can designate a first primary channel of the plurality of primary channels as a current primary channel of operating bandwidth, wherein the remaining one or more of the plurality of primary channels are one or more secondary primary channels. In addition, the processor 2712 may detect that the current primary channel of the operating bandwidth is busy. In response, processor 2712 may obtain another TXOP via a first secondary primary channel of the one or more secondary primary channels.

In some embodiments, processor 2712 may perform certain operations when obtaining another TXOP on the first secondary primary channel. For example, processor 2712 may perform respective backoff procedures on one or more secondary primary channels. Further, processor 2712 may obtain another TXOP by one of the one or more secondary primary channels, which may count down to 0 first for a respective backoff process in all of the one or more secondary primary channels. Further, processor 2712 may perform transmission on at least one first secondary primary channel.

In some embodiments, processor 2712 may perform additional operations. For example, for a particular duration, the processor 2712 may designate one of the one or more auxiliary primary channels as a new primary channel for operating bandwidth. In addition, the processor 2712 can change the current primary channel of operating bandwidth to one of the one or more secondary primary channels.

FIG. 28 illustrates an exemplary process 2800 in accordance with the present invention. Process 2800 may represent an aspect to implement various proposed designs, concepts, schemes, systems, and methods described above. More particularly, process 2800 may represent an aspect of the proposed concepts and schemes for transmission of partial bandwidth spectrum reuse in wireless communications in accordance with the present invention. Process 2800 may include one or more operations, actions, or functions illustrated by one or more of blocks 2810, 2820, and 2830. Although shown as discrete blocks, the various blocks of process 2800 can be broken up into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Further, the blocks/sub-blocks of process 2800 may be performed in the order shown in FIG. 28 or in a different order. Further, one or more blocks/sub-blocks of process 2800 may be performed repeatedly or iteratively. Process 2800 can be implemented in or by any variant of apparatus 2710 and apparatus 2720. For purposes of illustration only and not limitation, process 2800 is described in the context of STA110, where device 2710 is implemented or embodied as a wireless network, which may be a WLAN in network environment 100 according to one or more IEEE802.11 standards, and STA120, where device 2720 is implemented or embodied as a STA 120. Process 2800 begins at block 2810.

At 2810, process 2800 can involve processor 2712 of device 2710 detecting, via transceiver 2716, that a primary channel of an operating bandwidth of a plurality of channel segments is busy, the channel segments comprising the primary channel and at least one non-primary channel. Process 2800 may proceed from 2810 to 2820.

At 2820, in response to detecting that the primary channel is busy, process 2800 may involve processor 2712 obtaining a TXOP (e.g., a PBSR TXOP) over a first non-primary channel of the at least one non-primary channel via transceiver 2716. From 2820, process 2800 may proceed to 2830.

At 2830, process 2800 can involve, during the TXOP, processor 2712 performing, via transceiver 2712, a transmission on at least the first non-primary channel.

In some embodiments, process 2800 may involve processor 2712 performing certain operations in detecting that the main channel is busy. For example, process 2800 can involve processor 2712 performing a channel contention backoff process on a primary channel to access a medium on the primary channel. Further, in response to detecting that the primary channel is busy, process 2800 may involve processor 2712 halting the fallback process.

In some embodiments, process 2800 may involve processor 2712 receiving a frame from a transmission by an OBSS on a main channel upon detection of the main channel being busy. Alternatively, process 2800 can involve processor 2712 detecting that the signal energy on the primary channel is above an energy detection threshold.

In some embodiments, process 2800 can involve processor 2712 performing additional operations in obtaining a TXOP. For example, process 2800 may involve processor 2712 resuming a suspended fallback process or initiating a new fallback process such that the fallback counter counts down to 0 on the first non-primary channel. Further, process 2800 can involve processor 2712 initiating a TXOP on a first non-primary channel in response to the backoff counter counting down to 0 on the first non-primary channel. Further, during a particular time interval prior to the start of the TXOP, process 2800 can involve processor 2712 determining the bandwidth of the TXOP based on the medium state of each at least one non-primary channel other than the first non-primary channel. In some embodiments, the particular time interval may comprise a PIFS interval.

In some embodiments, process 2800 may involve processor 2712 executing a fallback process on a first non-primary channel within a selected channel segment when resuming a suspended fallback process or when initiating a new fallback process. Alternatively, process 2800 can involve processor 2712 performing multiple backoff processes on multiple non-primary channels of at least one non-primary channel within a respective channel segment.

In some embodiments, when initiating a TXOP, process 2800 can involve processor 2712 setting a duration of the TXOP according to a duration from the TOXP or length information of a PPDU transmitted by an OBSS receiving a frame. Alternatively, process 2800 can involve processor 2712 setting a duration of the TXOP to a particular value.

In some embodiments, process 2800 may involve processor 2712 performing DL transmissions to at least one non-AP device on at least one non-primary channel while performing transmissions on the first non-primary channel. Alternatively, process 2800 can involve processor 2712 triggering UL transmission from at least one non-AP device on at least one non-primary channel.

In some embodiments, process 2800 may involve processor 2712 performing certain operations in obtaining a TXOP. For example, process 2800 may involve processor 2712 maintaining a first fall-back functional state for a primary channel and a second fall-back functional state for a first non-primary channel. Further, process 2800 can involve processor 2712 performing EDCA backoff on the primary channel. Further, process 2800 can involve processor 2712 suspending EDCA backoff on the primary channel upon detecting that the primary channel is busy. Further, process 2800 may involve processor 2712 storing a value for each of a plurality of backoff parameters for EDCA backoff on the primary channel as a first backoff function state. In this case, the plurality of backoff parameters may include at least a backoff count, a contention window, and a QoS retry count.

In some embodiments, the at least one non-primary channel may comprise a plurality of non-primary channels (which include the first non-primary channel). In this case, process 2800 can involve processor 2712 performing additional operations in obtaining the TXOP. For example, process 2800 can involve processor 2712 invoking at least one fallback process by invoking respective fallback processes for at least one fallback process on a channel corresponding to the plurality of non-primary channels. Further, process 2800 can involve processor 2712 selecting a first non-primary channel to initiate a TXOP thereon in response to a respective backoff process on the first non-primary channel of the plurality of non-primary channels first counting down to 0.

In some embodiments, when invoking at least one fallback process, the process 2800 may involve the processor 2712 invoking at least one fallback process in parallel or sequentially by initializing at least one new fallback process or resuming a suspended fallback process on the primary channel.

In some embodiments, where the invocation of the at least one fallback process involves resuming a suspended fallback process, the respective fallback counter for each at least one fallback process may be initialized based on the first fallback functional state of the primary channel. In some embodiments, where the invocation of the at least one fallback process involves initializing a new fallback process for the first non-primary channel, the respective fallback counter for each at least one fallback process may be initialized based on the access category. In some embodiments, the second fallback functional state for the first non-primary channel may be reset. Further, the previously stored first fallback functional state may be restored on the primary channel.

In some embodiments, in obtaining a TXOP, process 2800 may involve processor 2712 performing an RTS and CTS frame exchange prior to any data or management frame transmission within the TXOP.

In some embodiments, after the TXOP, process 2800 may involve processor 2712(1) resuming a previous fallback process suspended on the primary channel in response to detecting that the primary channel is busy; or (b) invoke a new fallback procedure on the primary channel.

In some embodiments, after a TXOP, when obtaining a TXOP on a primary channel, process 2800 may involve processor 2712 performing an RTS and CTS frame exchange before any data or management frame transmission. In some embodiments, in performing RTS and CTS frame exchanges, process 2800 may involve processor 2712 performing RTS and CTS frame exchanges in response to one of: (11) unexpired synchronization timer (if any); and (2) PPDU update that NVA was not received

In some embodiments, process 2800 may involve processor 2712 performing additional operations. For example, for each of a plurality of channel segments having a plurality of channels per channel segment, process 2800 may involve processor 2712 designating one of the plurality of channels as a primary channel for a respective channel segment to generate a plurality of primary channels for the plurality of channel segments. Further, process 2800 can involve processor 2712 designating a first primary channel of a plurality of primary channels as a current primary channel for operating bandwidth, remaining one or more of the plurality of primary channels being one or more secondary primary channels. Further, process 2800 can involve processor 2712 detecting that a current primary channel for operating bandwidth is busy. In response, process 2800 can involve processor 2712 obtaining another TXOP with a first secondary primary channel of the one or more secondary primary channels.

In some embodiments, process 2800 may involve processor 2712 performing certain operations in obtaining another TXOP on the first secondary primary channel. For example, process 2800 can involve processor 2712 performing respective backoff on one or more secondary primary channels. Further, process 2800 can involve processor 2712 obtaining another TXOP by first counting down to one of 0 by a respective backoff process for one or more secondary primary channels. Further, process 2800 can involve processor 2712 performing a transmission on at least one first secondary primary channel.

In some embodiments, process 2800 may involve processor 2712 performing additional operations. For example, for a particular duration, process 2800 can involve processor 2712 designating one of the one or more secondary main channels as a new main channel of operating bandwidth. Further, process 2800 can involve processor 2712 changing a current primary channel of operating bandwidth to one of the one or more secondary primary channels.

The subject matter described herein sometimes illustrates different elements as being included in, or connected with, different other elements. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. Conceptually, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two elements herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial elements. Likewise, any two elements so associated can also be viewed as being "operably connected," or "operably coupled," to each other to achieve the desired functionality, and any two elements capable of being so associated can also be viewed as being "operably couplable," to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting elements and/or wirelessly cognizable and/or wirelessly interacting elements and/or logically interactable elements.

Furthermore, to the extent that substantially any plural and/or singular terms are used herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and application. Various singular/plural permutations may be expressly set forth herein for the sake of clarity.

Furthermore, those skilled in the art will understand that, in general, terms used herein, and especially terms used in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms, e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an," the same applies to indefinite articles such as "at least one" or "one or more. Furthermore, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least one of the recited number, and the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations. Further, where a convention analogous to "at least one A, B and C, etc." is used, in general such a construction is intended that one skilled in the art will understand the convention such that "a system has at least one A, B and C" will include but not be limited to systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B and C together, etc. In those instances where a convention analogous to "at least one A, B or C" is used, it is generally intended that such a construction will be understood by those skilled in the art that the convention such as "a system has at least one A, B or C" will include but not be limited to systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B and C together, and the like. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, in the description, claims, or drawings, will be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "a or B" will be understood to include the possibility of "a or B" or "a and B".

From the foregoing, it will be appreciated that various embodiments of the invention have been described herein for purposes of illustration, and that various modifications may be made without deviating from the scope and spirit of the invention. Accordingly, the various embodiments described herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

1. A method for partial bandwidth spectrum multiplexing transmission, the method comprising:

detecting that a primary channel of an operating bandwidth is busy, the operating bandwidth having a plurality of channel segments including the primary channel and at least one non-primary channel;

in response to detecting that the primary channel is busy, obtaining a transmission opportunity over a first non-primary channel of the at least one non-primary channel; and

performing transmission on at least the first non-primary channel during the transmission opportunity.

2. The method for partial-bandwidth spectrum multiplexing transmission of claim 1 wherein detecting that the primary channel is busy comprises:

performing a channel contention backoff procedure on the primary channel to access a medium of the primary channel; and

suspending the channel contention backoff process in response to detecting that the primary channel is busy.

3. The method for partial-bandwidth spectrum multiplexed transmission of claim 1, wherein the detecting that the primary channel is busy comprises:

detecting a frame from an overlapping basic service set on the primary channel; or

Detecting that a signal energy on the primary channel is above an energy detection threshold.

4. The method for partial-bandwidth spectrum multiplexing transmission of claim 1, wherein obtaining the transmission opportunity comprises:

resuming a suspended fallback process or initiating a new fallback process such that a fallback counter counts down on the first non-primary channel;

initiating the transmission opportunity on the first non-primary channel in response to the back-off counter counting down to 0 on the first non-primary channel; and

determining a bandwidth of a transmission opportunity during a specified time interval before the start of the transmission opportunity based on a medium status of each of the at least one non-primary channel except the first non-primary channel,

wherein the particular time interval comprises a point coordination function interframe space interval.

5. The method for partial-bandwidth spectrum multiplexing transmission of claim 4, wherein resuming the suspended fallback process or initiating the new fallback process comprises:

performing a back-off procedure on the first non-primary channel within the selected channel segment; or

Performing a plurality of fallback procedures on a plurality of non-primary channels of the at least one non-primary channel within a respective channel segment.

6. The method for partial-bandwidth spectrum multiplexing transmission of claim 4, wherein initiating the transmission opportunity comprises:

setting the time length of the transmission opportunity according to the received time length information of the transmission opportunity carried in the received frame from the overlapped basic service set or the time length information obtained by the length information of the received frame; or

Setting the duration of the transmission opportunity to a particular value.

7. The method for partial-bandwidth spectrum multiplexing transmission of claim 1, wherein performing the transmission on the first non-primary channel comprises:

performing downlink transmission on the at least one non-primary channel to at least one non-AP device; or

Triggering uplink transmissions from at least one non-AP device on the at least one non-primary channel.

8. The method for partial-bandwidth spectrum multiplexing transmission of claim 1, wherein obtaining the transmission opportunity comprises:

maintaining a first fallback functional state for the primary channel;

maintaining a second fallback functional state for the first non-primary channel;

performing enhanced distributed channel access backoff on the primary channel;

suspending the enhanced distributed channel access backoff on the primary channel upon detecting that the primary channel is busy; and

storing a value for each of a plurality of backoff parameters for the enhanced distributed channel access backoff on the primary channel as the first backoff functional state,

wherein the plurality of backoff parameters comprises at least: a backoff count, a contention window, and a quality of service STA retry count.

9. The method for partial-bandwidth spectrum multiplexed transmission of claim 1, wherein the at least one non-primary channel comprises a plurality of non-primary channels including the first non-primary channel, and wherein obtaining the transmission opportunity further comprises:

invoking at least one fallback process by invoking a corresponding fallback process on at least one of the plurality of non-primary channels; and

selecting the first non-primary channel to initiate the transmission opportunity in response to a back-off procedure on the first non-primary channel first counting down to 0 in the plurality of non-primary channels.

10. The method for partial-bandwidth spectrum multiplexing transmission of claim 9, wherein invoking the at least one fallback process comprises invoking the at least one fallback process in parallel or sequentially by initializing at least one new fallback process or resuming a suspended fallback process on the primary channel.

11. The method for partial-bandwidth spectrum multiplexed transmission of claim 9, wherein in the event that invoking the at least one fallback process comprises resuming the suspended fallback process, a fallback counter for each of the at least one fallback process is initialized based on a first fallback functional state of the primary channel.

12. The method for partial-bandwidth spectrum multiplexing transmission of claim 9, wherein initializing a backoff counter for each of the at least one backoff process based on an access category if invoking the at least one backoff process comprises initializing a new backoff process for the first non-primary channel.

13. The method for partial-bandwidth spectrum multiplexed transmission of claim 9, wherein a second fallback functional state for the first non-primary channel is reset, and wherein a previously stored first fallback functional state is resumed on the primary channel at the end of the transmission opportunity obtained on the first non-primary channel.

14. The method for partial-bandwidth spectrum multiplexing transmission of claim 1, wherein obtaining the transmission opportunity comprises:

within the transmission opportunity, request-to-send and clear-to-send frame exchanges are performed prior to any data or management frame transmission.

15. The method for partial-bandwidth spectrum multiplexed transmission according to claim 1, wherein the method further comprises:

resuming, after the transmission opportunity, a previous fallback procedure on the primary channel suspended in response to detecting that the primary channel is busy; or

After the transmission opportunity, a new fallback procedure is invoked on the primary channel.

16. The method for partial-bandwidth spectrum multiplexed transmission according to claim 1, wherein the method further comprises:

after the transmission opportunity, when a transmission opportunity is obtained on the primary channel, request-to-send and clear-to-send frame exchanges are performed before any data or management frame transmission.

17. The method for partial-bandwidth spectrum multiplexing transmission of claim 16, wherein performing request-to-send and clear-to-send frame exchanges comprises:

performing the request transmission and the clear to transmit frame exchange in response to the synchronization timer not having expired; and

the request transmission and the clear to transmit frame exchange are performed in response to a PPDU update for which the network allocation vector was not received.

18. The method for partial-bandwidth spectrum multiplexed transmission according to claim 1, wherein the method further comprises:

for each channel segment having a plurality of channels, designating one of the plurality of channels as a primary channel for the respective channel segment to generate the plurality of primary channels for the plurality of channel segments;

designating a first primary channel of the plurality of primary channels as a current primary channel for the operating bandwidth, the remaining one or more primary channels of the plurality of primary channels being one or more secondary primary channels;

detecting that the current primary channel of the operating bandwidth is busy; and

in response to detecting that the current primary channel is busy, obtaining another transmission opportunity through a first secondary primary channel of the one or more secondary primary channels.

19. The method for partial-bandwidth spectrum multiplexed transmission according to claim 18, wherein obtaining the another transmission opportunity over the first secondary primary channel comprises:

performing respective fallback procedures on the one or more secondary primary channels;

obtaining the other transmission opportunity through the first secondary primary channel counting down to 0 first by a backoff procedure among all of the one or more secondary primary channels; and

performing a transmission on at least the first secondary primary channel.

20. The method for partial-bandwidth spectrum multiplexed transmission according to claim 18, wherein the method further comprises:

designating one of the one or more secondary primary channels as a new primary channel for the operating bandwidth during a particular duration; and

changing the current primary channel for the operating bandwidth to the auxiliary primary channel.

21. An apparatus for partial-bandwidth spectrum multiplexing transmission, the apparatus comprising one or more processors and memory, execution by the one or more processors of instructions stored in the memory causing the apparatus to perform a method of partial-bandwidth spectrum multiplexing transmission, the method comprising: