Collision detection and resolution for prioritized full-duplex communication

Abstract

A preamble-based collision detection mechanism for use in a wireless local area network (WLAN) having one or more full-duplex (FD) stations. Also described is a new collision resolution estimation and scheduling mechanism for prioritized communications. These techniques can enable faster collision detection and resolution without the need to perform self-interference (SI) estimation. The techniques include using orthogonal preambles in which FD stations embed priority information in the time and / or frequency domains.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Patent Application No. 17 / 819,285, filed August 11, 2022, which is incorporated herein by reference in its entirety. This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 261,062, filed September 9, 2021, which is incorporated herein by reference in its entirety.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable

[0003] Notification of copyrighted material Portions of the material in this patent document may be subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the reproduction by any third party of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office publicly available files or records, but otherwise reserves all copyright rights. The copyright owner does not hereby waive any rights to have this patent document maintained in secrecy, including, but not limited to, the right pursuant to 37 CFR § 1.14.

[0004]

[0005] The techniques of this disclosure relate generally to wireless local area networks (WLANs), and more particularly to full-duplex WLANs that address the problem of self-interference. [Background technology]

[0005]

[0007] The use of full-duplex (FD) technology on wireless local area networks (WLANs) is becoming increasingly important due to its ability to increase spectral efficiency.

[0006]

[0008] However, the use of FD raises issues regarding self-interference (SI) of the FD device as it is received by the same device through transceiver coupling and multipath reflections. Summary of the Invention [Problem to be solved by the invention]

[0007]

[0009] Therefore, there is a need for FD techniques that address the issue of SI. The present disclosure fulfills this need and provides additional benefits. [Means for solving the problem]

[0008]

[0010] A novel preamble-based collision detection apparatus and method that can be performed without self-interference (SI) estimation, and a novel collision resolution estimation and scheduling mechanism for communications with prioritized traffic are disclosed.

[0009]

[0011] A collision detection (CD) mechanism can detect collisions more quickly using orthogonal (e.g., time / frequency domain) preambles in the time or frequency domain. In at least one embodiment, priority information is embedded in the preamble. The priority level can be predetermined and agreed upon by all FD STAs. This priority information can be embedded in the FD preamble field that follows the legacy preamble field specified in 802.11. FD STAs can handle the detection of a colliding preamble in different ways, which may depend on their relative priorities.

[0010]

[0012] In at least one embodiment, a mechanism can ensure prioritized transmission after the process of intra-BSS collision estimation, for example, by allowing FD STAs to indicate priority in control frames used for collision avoidance and / or by allowing FD scheduler STAs to process higher priority traffic before lower priority traffic when intra-BSS collision is estimated.

[0011]

[0013] In at least one embodiment, an FD STA can initiate a transmit opportunity (TXOP) that includes a request-to-send / clear-to-send (RTS / CTS) exchange.

[0012]

[0014] There are many possible implementations of the disclosed technology, examples of which are described throughout this specification.

[0013]

[0015] Further aspects of the technology described herein will become apparent in the remainder of this specification, and this detailed description is intended to fully disclose preferred embodiments of the technology without limiting them.

[0014]

[0016] The techniques described herein will be better understood by reference to the following drawings, which are for illustrative purposes only. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a plot to show various noise sources, including SI, comparing what is believed to be transmitted with what is actually received. [Figure 2] FIG. 1 is a plot to show various noise sources, including SI, comparing what is believed to be transmitted with what is actually received. [Figure 3] FIG. 1 is a diagram of SIC requirements for analog cancellation and digital cancellation based on a transmitted signal including subcomponents. [Figure 4] A diagram showing an FD preamble that can be designated as an FD standalone training frame. [Figure 5] FIG. 10 illustrates an FD preamble that can be added to an existing frame. [Figure 6]FIG. 1 is a block diagram of a full-duplex transceiver including analog and digital SIC, showing that there is an RF / analog self-interference cancellation (SIC) and a baseband / digital SIC element between each pair of Tx and Rx chains, in accordance with at least one embodiment of the present disclosure. [Figure 7] FIG. 1 is a hardware block diagram of station (STA) hardware in accordance with at least one embodiment of the present disclosure. [Figure 8] FIG. 1 is a hardware block diagram of a station configuration as included in multi-link device (MLD) hardware, in accordance with at least one embodiment of the present disclosure. [Figure 9] FIG. 1 illustrates an example network topology for asymmetric FD, as used for demonstration purposes, in accordance with at least one embodiment of the present disclosure. [Figure 10] FIG. 1 illustrates an example network topology for symmetric FD as used for demonstration purposes, in accordance with at least one embodiment of the present disclosure. [Figure 11] FIG. 1 illustrates an example network topology with an AP and multiple FD stations for demonstration purposes, in accordance with at least one embodiment of the present disclosure. [Figure 12] FIG. 1 is a block diagram of a self-interference path for a dual antenna element illustrating various forms of interference. [Figure 13] FIG. 1 is a block diagram of a self-interference path of a single antenna element illustrating various forms of interference. [Figure 14] FIG. 10 is a signal diagram of orthogonalizing time domain signals in an FD preamble for collision detection in accordance with at least one embodiment of the present disclosure. [Figure 15] FIG. 1 is a signal diagram of a preamble field and an FD preamble in the time domain and frequency domain, in accordance with at least one embodiment of the present disclosure. [Figure 16] FIG. 10 is a signal diagram of frequency domain collisions between different prioritized preambles in accordance with at least one embodiment of the present disclosure. [Figure 17]FIG. 10 is a signal diagram of a collision between frequency domain preambles indicating the same priority, in accordance with at least one embodiment of the present disclosure. [Figure 18] FIG. 10 is a signal diagram of collision detection between prioritized preambles and legacy preambles in accordance with at least one embodiment of the present disclosure. [Figure 19] FIG. 19 illustrates an example network topology used for FIG. 18, in accordance with at least one embodiment of the present disclosure. [Figure 20] FIG. 10 is a flow diagram for a transmitting station to react to the detection of a collision, in accordance with at least one embodiment of the present disclosure. [Figure 21] FIG. 6 illustrates an example network topology to illustrate the problem in Section 6.2, in accordance with at least one embodiment of the present disclosure. [Figure 22] FIG. 2 is a communication diagram of Example 2-1 for performing HP traffic admission including PR+CDP frames, in accordance with at least one embodiment of the present disclosure. [Figure 23] FIG. 2 is a communication diagram of Example 2-1-0 in which an FD AP triggers LP traffic without receiving any response from an authorized HP traffic destination, in accordance with at least one embodiment of the present disclosure. [Figure 24] FIG. 2 is a communication diagram of Example 2-1-1 in which FD STA1 re-accesses the channel without receiving a trigger from the FD AP, in accordance with at least one embodiment of the present disclosure. [Figure 25] FIG. 10 is a communication diagram of Example 2-1-2 of HP traffic admission without PR+CDP frames, in accordance with at least one embodiment of the present disclosure. [Figure 26] FIG. 2 is a communication diagram of Example 2-2 of HP traffic admission when an AP has an LP, in accordance with at least one embodiment of the present disclosure. [Figure 27] FIG. 2 illustrates an example network topology used to explain Example 2-2 of HP traffic admission when an AP has an LP, in accordance with at least one embodiment of the present disclosure. [Figure 28]10A-10C illustrate example network topologies for illustrating enhanced examples 2-3 of the effect of OBSS collisions on OBSS interference, in accordance with at least one embodiment of the present disclosure. [Figure 29] 10A-10C illustrate example network topologies for illustrating enhanced examples 2-3 of the effect of BSS collisions on intra-BSS interference, in accordance with at least one embodiment of the present disclosure. [Figure 30] 1 illustrates an example network topology in which an AP may overestimate collisions, as described in accordance with at least one embodiment of the present disclosure. [Figure 31] FIG. 31 is a communication diagram for resolving the example over-estimated collision case 2 of FIG. 30 in accordance with at least one embodiment of the present disclosure. [Figure 32] FIG. 10 is a flow diagram of the operation of an FD AP when a TXOP including a combination of P-RTS and P-CTS is initiated, in accordance with at least one embodiment of the present disclosure. [Figure 33] FIG. 10 is a flow diagram of the operation of an FD AP when a TXOP including a combination of P-RTS and P-CTS is initiated, in accordance with at least one embodiment of the present disclosure. [Figure 34] FIG. 10 is a flow diagram of the operation of an FD AP when a TXOP including a combination of P-RTS and P-CTS is initiated, in accordance with at least one embodiment of the present disclosure. [Figure 35] FIG. 10 is a flow diagram of the operation of an FD AP when a TXOP including a combination of P-RTS and P-CTS is initiated, in accordance with at least one embodiment of the present disclosure. [Figure 36] FIG. 10 is a flow diagram of an FD STA's operation when initiating a TXOP that includes a P-RTS, P-CTS combination, in accordance with at least one embodiment of the present disclosure. [Figure 37] FIG. 10 is a flow diagram of an FD STA's operation when initiating a TXOP that includes a P-RTS, P-CTS combination, in accordance with at least one embodiment of the present disclosure. [Figure 38]FIG. 10 is a flow diagram of an FD STA's operation when initiating a TXOP that includes a P-RTS, P-CTS combination, in accordance with at least one embodiment of the present disclosure. [Figure 39] FIG. 3 is a communication diagram of Example 3-1 of HP traffic grant for a PPDU-initiated TXOP in accordance with at least one embodiment of the present disclosure. [Figure 40] FIG. 3 is a communication diagram of Example 3-2 of HP traffic admission including overestimated intra-BSS collisions, in accordance with at least one embodiment of the present disclosure. [Figure 41] FIG. 3 is a communication diagram of Example 3-3 of HP traffic admission for a PPDU-initiated TXOP when the AP has an LP, in accordance with at least one embodiment of the present disclosure. [Figure 42] 10A-10C are communication diagrams of example 3-4 of HP traffic admission for a PPDU-initiated TXOP when the AP has an LP, in accordance with at least one embodiment of the present disclosure. [Figure 43] 1 is a flow diagram of an FD STA initiating a TXOP containing a DATA PPDU, in accordance with at least one embodiment of the present disclosure. [Figure 44] 1 is a flow diagram of an FD STA initiating a TXOP containing a DATA PPDU, in accordance with at least one embodiment of the present disclosure. [Figure 45] 1 is a flow diagram of an FD STA initiating a TXOP containing a DATA PPDU, in accordance with at least one embodiment of the present disclosure. [Figure 46] 1 is a flow diagram of a non-AP STA initiating a TXOP containing a DATA PPDU, in accordance with at least one embodiment of the present disclosure. [Figure 47] 1 is a flow diagram of a non-AP STA initiating a TXOP containing a DATA PPDU, in accordance with at least one embodiment of the present disclosure. [Figure 48] FIG. 1 is a data field diagram of a P-RTS frame in accordance with at least one embodiment of the present disclosure. [Figure 49]FIG. 49 is a data field diagram of the PR control field from FIG. 48 in accordance with at least one embodiment of the present disclosure. [Figure 50] FIG. 10 is a data field diagram of a P-CTS frame in accordance with at least one embodiment of the present disclosure. [Figure 51] FIG. 51 is a data field diagram of the PR control field shown in FIG. 50 in accordance with at least one embodiment of the present disclosure. [Figure 52] FIG. 10 is a data field diagram of a PR+CDP frame in accordance with at least one embodiment of the present disclosure. [Figure 53] FIG. 53 is a data field diagram of the PR+CDP control field as seen in FIG. 52. DETAILED DESCRIPTION OF THE INVENTION

[0016] 1. Conventional state-of-the-art technology

[0060] Full-duplex (FD) technology is under consideration in the 802.11 FD Technical Interest Group (TIG), and as of this writing, no FD technology standard exists. Benefits of FD include the ability to simultaneously transmit and receive radio signals sharing the same frequency resources, thus potentially doubling the spectral efficiency of bidirectional links compared to half-duplex links.

[0017]

[0061] The challenge is to efficiently and sufficiently cancel the self-interference (SI) transmitted by an FD device and received by the same device through transceiver coupling and multipath reflections.

[0018]

[0062] There are many use cases for the technology, including, for example, virtual reality (VR), augmented reality (AR), telemedicine, etc.

[0019] 1.1. Self-Interference Cancellation (SIC)

[0064] Figures 1 and 2 show the spectrum (power and frequency) of the expected transmission (Figure 1) and that which was actually transmitted (Figure 2). The result is that the signal originally transmitted by the STA is as seen in Figure 1, while the actual transmitted signal is as shown in Figure 2. Many analog components in the transceiver distort the original signal as seen in Figure 1 by adding transmitter noise and harmonics to the transmitted signal, resulting in the received signal as shown in Figure 2.

[0020]

[0065] Figure 3 shows the self-interference cancellation (SIC) requirements of FD to sufficiently cancel any self-interference so that the interference power is reduced to the level of the receiver noise floor (-90 dBm). On the left side of the figure, we see the transmitted signal, which includes 110 dB of the main signal, 80 dB of harmonics, and 50 dB of transmitter noise. On the right side of the figure, we see what is picked up at the receiver and the contribution of the noise cancellation. The noise cancellation includes 60 dB of analog SIC cancellation, which allows the receiver chain to meet a 10 dB peak-to-average power ratio (PAPR) at receiver saturation. It also includes 50 dB of digital SIC cancellation, which results in a receiver noise floor of -90 dBm using SIC.

[0021]

[0066] Therefore, SIC should provide the following capabilities: (1) Any FD system should provide 110 dB of linear self-interference cancellation to reduce SI to the receiver noise floor. This allows for the rejection of the strongest main signal component (110 dB) above the noise floor. (2) Any FD system should reduce nonlinear harmonic components by 80 dB above the noise floor. (3) Any FD system should have an analog cancellation component that provides at least 50 dB of analog noise cancellation to cancel transmitter noise. (4) If the input signal exceeds a certain level determined by the analog-to-digital converter (ADC) resolution, the receiver (RX) chain in the radio may saturate. Therefore, as shown in Figure 3, since the transmitted SI can be as low as 20 dBm, the FD system must have analog cancellation that provides 60 dB of SI reduction and meet the Rx saturation level requirement, including a 10 dB margin for the peak-to-average power ratio (PAPR). Furthermore, digital cancellation that provides 50 dB of SI reduction achieves a receiver noise floor of -90 dBm.

[0022] 1.2. Prioritized Communications

[0068] In 802.11, intra-access category (AC) communication prioritization provides six transmission queues that map to four Enhanced Distributed Channel Access Functions (EDCAFs) to differentiate between traffic streams in the same AC and provide finer prioritization between AC_VI or AC_VO streams.

[0023] 1.3. Previously Proposed Solutions

[0070] To avoid time wastage due to collisions, a collision detection based on FD-assisted collision detection is proposed to stop simultaneous transmissions from FD devices. Further FD-assisted EDCA access including contention resolution is also proposed to accelerate collision recovery. FD-assisted Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) is proposed to improve the efficiency of existing MAC protocols. An FD preamble is proposed that needs to be flexible enough to facilitate self-interference cancellation (SIC).

[0024]

[0071] 4 and 5 show an FD preamble that can be designated as an FD stand-alone training frame, as in FIG. 4, or that can be appended to an existing frame, as seen in FIG.

[0025]

[0072] A solution has been analyzed and / or proposed: Self-Interference Cancellation (SIC) to cancel self-interference to FD transceivers.

[0026]

[0073] Existing solutions require full SIC, and current collision detection solutions cannot distinguish between different priorities of colliding signals, so they usually stop transmission from both sides to avoid further collisions.

[0027] 2. Contribution of this Disclosure

[0075] A full-duplex (FD) collision detection methodology is described that utilizes prioritized preambles defined in a new FD preamble field. Collision detection for prioritized preambles does not require full self-interference cancellation (SIC). Using collision detection based on the FD preamble without SIC improves the transmission efficiency of the detecting STA, allowing it to stop transmitting the remainder of the physical layer protocol data unit (PPDU) to avoid further collisions.

[0028]

[0076] Additionally, this disclosure describes another collision resolution method for prioritized streams that allows highly prioritized streams to have earlier access than lower prioritized streams when intra-BSS collisions occur.

[0029] 3. Hardware Implementation

[0078] 6 illustrates an example embodiment 10 of self-interference cancellation (SIC) hardware as utilized in a station having a radio frequency front end (RFFE) 30. This SIC hardware is utilized in a wireless local area network (WLAN), such as the STA shown in FIG. 7 and the MLD shown in FIG. 8 below.

[0030]

[0079] The Tx digital BB 12 is the baseband transmit (TX) signal. The baseband digital signal accumulates harmonics and transmitter noise through modulation by a digital-to-analog converter (DAC) and upconverter (UC) 14 into a passband signal. Before the transmit signal is sent to the TX antenna 16, a small portion of the transmit signal, including the transmitter noise, passes through circuitry 15 to perform analog SIC.

[0031]

[0080] The SIC circuit consists of parallel fixed lines of variable delays 26a-26n and tunable attenuators 28a-28n, which are then summed together and this combined signal is then subtracted 23 from the signal on the receive path.

[0032]

[0081] The passband signal received from antenna 22 has SIC correction applied (23) and passes through an analog-to-digital converter (ADC) and downconverter (DC) 20. The baseband digital signal from the ADC and DC has digital SIC (24) applied (19) to estimate the remaining residual self-interference, including the main TX SI, after analog cancellation and any delayed reflections of this signal from the environment, to produce the receiver digital baseband signal (18).

[0033]

[0082] FIG. 7 illustrates an example embodiment 50 of STA hardware configured to execute the protocol of the present disclosure. An external I / O connection 54 preferably couples to an internal bus 56 of circuitry 52, to which a CPU 58 and memory (e.g., RAM) 60 are connected for executing programs implementing the communications protocol. The host machine contains at least one modem 62 to support communications, which is coupled to at least one RF module 64, 68, each of which is connected to one or more antennas 69, 66a, 66b, 66c, ..., 66n. RF modules containing multiple antennas (e.g., antenna arrays) enable beamforming during transmission and reception. In this manner, the STA can transmit signals using a set of multiple beam patterns.

[0034]

[0083] The bus 54 allows for connecting various devices to the CPU, e.g., sensors, actuators, etc. Executing on the processor 58 are instructions from a memory 60 for executing programs that implement a communication protocol, allowing the STA to perform the functions of an Access Point (AP) station or a regular station (non-AP STA). It should also be understood that the programming may be configured to operate in different modes (TXOP holder, TXOP sharing participant, source, intermediate, destination, first AP, other AP, station associated with first AP, station associated with other AP, coordinator, coordinator, AP in OBSS, STA in OBSS, etc.) depending on what role it is performing in the current communication context.

[0035]

[0084] The illustrated STA HW is therefore configured to include at least one modem and associated RF circuitry to provide communications in at least one band, with this disclosure primarily directed to the sub-6 GHz band.

[0036]

[0085] It should be understood that the present disclosure can be configured to include multiple modems 62, each coupled to any number of RF circuits. In general, the more RF circuits used, the wider the coverage of the antenna beam direction. It should be understood that the number of RF circuits and antennas utilized will depend on the hardware constraints of a particular device. Some RF circuits and antennas can be disabled when a STA determines that it does not need to communicate with neighboring STAs. In at least one embodiment, the RF circuitry is connected to multiple antennas, including frequency converters and array antenna controllers, that are controlled to perform beamforming for transmission and reception. In this manner, a STA can transmit signals using a set of multiple beam patterns, with each beam pattern direction being considered an antenna sector.

[0037]

[0086] Furthermore, it should be noted that multiple instances of station hardware such as those shown in the figures can be combined into a multi-link device (MLD), which typically has a processor and memory for coordinating activity, but a separate CPU and memory are not always required for each STA within the MLD.

[0038]

[0087] FIG. 8 shows an example embodiment 90 of a multi-link device (MLD) hardware configuration. The MLD can include a soft AP MLD, which is an MLD consisting of one or more associated STAs operating as an AP. The soft AP MLD should support multiple radio operation at 2.4 GHz, 5 GHz, and 6 GHz. Among the multiple radios, the basic link set is a link pair that satisfies simultaneous transmit / receive (STR) mode, such as a basic link set (2.4 GHz and 5 GHz) or a basic link set (2.4 GHz and 6 GHz).

[0039]

[0088] A conditional link is a link that forms a non-simultaneous transmit / receive (NSTR) link pair that includes several fundamental links. For example, these link pairs can include a 6 GHz link as a conditional link corresponding to the 5 GHz link when the 5 GHz is the fundamental link, and when the 6 GHz is the fundamental link, the 5 GHz link is a conditional link corresponding to the 6 GHz link. Soft APs are used in different scenarios, including Wi-Fi hotspots and tethering.

[0040]

[0089] Multiple STAs are associated with the MLD, each operating on a different frequency link. The MLD has external I / O access to applications, which connect to an MLD management entity 98 having a CPU 112 and memory (e.g., RAM) 114 to run programs that implement communication protocols at the MLD level. The MLD distributes tasks to each associated station (shown here as STA1 92, STA2 94, ..., STA_N 96) to which the MLD is connected, collects information from each associated station, and can share information among the associated STAs.

[0041]

[0090] In at least one embodiment, each STA in the MLD has its own CPU 100 and memory (RAM) 102, which are coupled via a bus 108 to at least one modem 104, which in turn is connected to at least one RF circuit 106, which in turn has one or more antennas. In this example, the RF circuit has multiple antennas 110a, 110b, 110c, ..., 110n, e.g., an antenna array. The modem, in conjunction with the RF circuit and associated antennas, transmits / receives data frames to / from neighboring STAs. In at least one implementation, the RF module includes a frequency converter, an array antenna controller, and other circuitry for interfacing with the antennas.

[0042]

[0091] It should be understood that each STA in an MLD does not necessarily require its own processor and memory, as they may share resources with each other and / or with an MLD management entity, depending on the particular MLD implementation. The above MLD illustration is provided by way of example and not limitation, and it should be understood that the present disclosure can work with a wide range of MLD implementations.

[0043] 4. Architecture 4.1.FD Implementation Example

[0094] 9 illustrates an example embodiment 150 of an asymmetric FD architecture in which FD AP 152 is simultaneously transmitting to FD STA1 154 and receiving from FD STA2 156. In this case, the transmitted signal from the FD AP's TX antenna generates self-interference and is received by the FD AP's RX antenna.

[0044]

[0095] 10 illustrates an example embodiment 160 of a symmetric FD architecture in which an FD AP 162 transmits to and receives from another FD STA 164. The FD AP and FD STA receive self-interference generated by themselves.

[0045] 4.2.Network Topology

[0097] FIG. 11 illustrates an example embodiment 170 of a network topology used in the examples by way of illustration and not limitation, which also applies to other topologies illustrated herein.

[0046]

[0098] This example shows three FD transceivers as FD AP 172, FD STA1 174, and FD STA2 176. The FD AP, FD STA1, and FD STA2 are within communication range of each other (e.g., they can "hear" each other). FD STA1 and the FD AP begin transmission at the same time. FD STA1 transmits a PPDU to the FD AP, while the FD AP transmits a PPDU to FD STA2. FD STA1 and the FD AP receive SI before SIC processing is performed.

[0047] 5. Prioritized FD

[0100] In the scenario considered, two FD STAs of different priorities within range of each other transmit PPDUs at the same time. The preamble of the PPDU may have an indication of the priority.

[0048]

[0101] Figures 12 and 13 show example self-interference paths 180, 200 for dual and single antennas. As shown in Figure 12, STA 182 includes a transmit chain 184 to antenna 186 and a receive chain 188 from antenna 190. The diagram shows leakage between the antennas, reflections due to the transceiver structure, and external reflections (192). As shown in Figure 13, STA 182 includes a transmit chain 184 coupled (202) to a single antenna 210 and a receive chain 188 coupled (204) to the same antenna 210. The diagram shows leakage between the transmit and receive chains, reflections due to antenna mismatch, reflections due to the environment, and external reflections (212).

[0049] 5.1. Collision Detection Issues for Prioritized FDs

[0103] Self-interference cancellation (SIC) is one of the major challenges in 802.11 FD technology. Current FD technology attempts to perform preamble-based collision detection after completing self-interference cancellation (SIC). However, there is no mechanism to perform preamble-based collision detection before SI channel estimation.

[0050]

[0104] If the FD transceiver did not perform a self-interference (SI) estimation of the external reflections of the SI (as shown in FIGS. 12 and 13), the FD transceiver would not recognize the presence of another signal.

[0051]

[0105] Also, an FD transceiver may not be able to determine that a collision has occurred by listening to its own preamble and based on a cyclic redundancy check (CRC): the colliding signal is too weak compared to the self-interference of its own preamble (e.g., encoded with MCS0).

[0052] 5.2. Solutions for Collision Detection for Prioritized FDs

[0107] The following are techniques to address these self-interference (SI) issues: (1) Priority information is included in the FD preamble for collision detection and resolution. In this case, collision detection does not require full SIC. (2) Each STA transmits the FD preamble of a PPDU carrying a priority signal that is orthogonal to other priority signals carried by the FD preambles of other STAs. For example, orthogonal priority signals can be preconfigured. (3) When a collision is detected, a STA with a higher priority should retransmit the PPDU. (4) A STA with a lower or equal priority should stop (pause) its transmission and initiate a backoff procedure after detecting the medium is idle again. (5) A STA detects a collision without detecting the priority of the colliding FD preamble, and therefore, the STA should stop transmission and initiate a backoff procedure after detecting the medium is idle (available).

[0053] 5.2.1. Collision Detection Using Time-Domain Quadrature Signals

[0109] The following description is based on the topology shown in Figure 11, where FD STA1 transmits a PPDU to the FD AP, and at the same time, the FD AP transmits a PPDU to FD STA2. The FD AP and FD STA1 receive signals during their transmissions. The received signals include self-interference signals and interference signals from other STAs. The following describes the use of time-domain signals in the FD preamble.

[0054]

[0110] 14 shows an example embodiment 220 for orthogonalizing time domain signals in an FD preamble for use in collision detection. Blocks 222 and 224 represent orthogonal frequency division multiplexing (OFDM) symbols (defined as data samples including a cyclic prefix (CP)), which in this case are approximately 3 μs in the time domain.

[0055]

[0111] The window size (shown as a vertical dashed box) represents the duration of an OFDM symbol duration without CP. Assume the detecting STA is FD STA1 and the colliding STA is FD AP. The top symbol 222 is colliding with the FD preamble signal of the STA with priority 2. The bottom symbol 224 is detecting the STA's own FD preamble with priority 1.

[0056] 5.2.2. Example 1-1: CD using TD quadrature signals

[0113] This example builds on the contents of Section 5.2.1 and describes the collision detection procedure.

[0057]

[0114] (a) Before transmitting the FD preamble, the STA, which is an FD transceiver, did not perform channel estimation of self-interference (SI) from external surroundings.

[0058]

[0115] (b) Before transmission, the FD preambles of different STAs should be encoded, which means multiplying them by different column vectors of the P matrix before transmission to make the FD preambles orthogonal to each other.

[0059]

[0116] Before performing self-interference cancellation, for collision detection, an orthogonal matrix (in this case, TIFF0007733137000001.tif8150) The P matrix can be constructed based on existing 802.11 standards, or any other desired orthogonal matrix can be utilized.

[0060]

[0117] Different priorities of the FD preamble are reflected by different columns of the P matrix. The P matrix is ​​pre-configured so that the STAs can know the priority represented by each column.

[0061]

[0118] For example, [x0,x0] are two symbols as part of the FD preamble, and two x0 symbols are the same. STA1 (with priority 1) multiplies [x0,x0] by the first column of the P matrix and sends out [x0,x0]. STA2 is a colliding STA (with priority 2), and multiplies [x0,x0] by the second column of the P matrix and sends out [x0,-x0].

[0062]

[0119] (c) At this stage, if each FD transceiver is simultaneously transmitting and receiving FD preambles, it becomes a simple process for detecting the presence of an FD preamble from another STA, which can be done before performing SI estimation.

[0063]

[0120] For example, STA1 receives y0 when it is sending the first x0 symbol. y0 is TIFF0007733137000002.tif6170. In the above equation, h1 and h2 are the channel coefficients from self-interference and from STA2 to STA1, respectively. Note that [h1, h2] are unknown at this stage before channel estimation. STA1 is simultaneously receiving y1 when it is sending the second x0 symbol. y1 is TIFF0007733137000003.tif6170. After receiving y0 and y1, STA1 can detect a collision by subtracting y1 from y0. This is TIFF0007733137000004.tif6170. STA1 recognizes this result as representing a collision, because if there is no collision, y0(no collision)= TIFF0007733137000005.tif6170 and y1(no collision)= TIFF0007733137000006.tif6170, This is because the result is TIFF0007733137000007.tif6170.

[0064]

[0121] (d) When a STA detects a colliding FD preamble, it should decide whether to retransmit the frame or stop (pause) transmission and perform a backoff after sensing that the channel medium is idle. In at least one embodiment, the decision is made based on comparing the STA's own priority with the priority indicated in the FD preamble received from the colliding STA.

[0065]

[0122] It should be understood that different priorities are reflected by different orthogonal column vectors of the P matrix.

[0066]

[0123] The prioritized FD preambles are encoded using the same P matrix, and an FD STA that detects a colliding FD preamble based on step (c) can derive the P matrix vector / priority used by the colliding STA. For example, STA1 detects a collision by subtracting y1 from y0. This is because, as explained in (c), TIFF0007733137000008.tif6150. STA1 recognizes that this result represents a collision. STA1 uses the [1,1] vector of the P matrix to represent priority 1. Using this information, STA1 can derive that the colliding FD preamble is encoded with the [1,-1] vector of the P matrix, which represents priority 2.

[0067]

[0124] If the STA has a high priority, it should retransmit the PPDU, otherwise it should immediately stop transmitting the PPDU and back off after detecting that the medium is idle.

[0068] 6. Carrier Frequency Offset (CFO) Issue Description

[0126] Significant (heavy) levels of carrier frequency offset (CFO) can impair the orthogonality between the two signals, in which case the above proposed solutions may suffer from performance degradation when transmitting time-domain orthogonal signals.

[0069]

[0127] Example: Consider collision detection using time-domain quadrature signals including CFO. When a signal from another STA is observed by a STA, TIFF0007733137000009.tif6170 with a linear phase offset, where f dis the CFO, which has a maximum of 40 ppm (parts per million) in the IEEE standard. The above assumes an OFDM symbol duration of 12.8 μs when the subcarrier spacing is 78.125 kHz. We also assume a very long cyclic prefix (CP) of approximately 3 μs (round trip delay for a 450 m BSS). f d When π is equal to 39 kHz, which is 7.8 ppm of 5 GHz, the phase offset between the second and first symbols of the collision FD preamble is π (before applying the 1,-1 orthogonal cover). Therefore, the collision FD preamble, together with the self-interference, is completely canceled. Therefore, in this case, the STA cannot detect the collision.

[0070] Lack of synchronization added to the issue description in section 6.1.5.1

[0129] If the two parties involved in the collision do not have synchronized center frequencies, the time-domain orthogonal signals may lose their orthogonality entirely.

[0071] 6.1.1. Proposed Solutions to the Lack of Synchronization

[0131] The following is a description of a solution according to the present disclosure to overcome the lack of proper center frequency synchronization: The FD preamble contains priority information embedded in the frequency domain. Different priorities can be carried by different subcarriers or tones of the FD preamble, spaced at least 40 ppm apart.

[0072]

[0132] In the baseband signal received after analog cancellation and before digital cancellation (note that digital cancellation requires SI channel estimation), a STA zeros out the tones of its own FD preamble to discover other STAs with different priorities.

[0073]

[0133] If an FD STA detects a colliding FD preamble as having a lower priority than its own, it should retransmit the FD preamble and the remainder of the PPDU. Otherwise, the STA should stop (pause) transmission and begin the backoff process after detecting that the channel medium is idle again. In response to receiving a retransmitted FD preamble from a higher-priority STA, the receiver can resynchronize and estimate the channel.

[0074] 6.1.2. FD Orthogonal and Prioritized FD Preamble

[0135] As specified in the 802.11 standard, the transmitted center frequency tolerance should be ±20 ppm relative to 20 MHz. When parts per million (ppm) is used to indicate frequency accuracy, it should be understood that an accuracy of, for example, 20 ppm indicates that the average frequency of the clock may be off by 20 Hz for every 1 MHz of its specified value.

[0075]

[0136] Different priorities can be conveyed by different subcarriers and / or tones of the transmitted FD preamble. Each STA only transmits one or some of the resulting tones to convey its priority. The tones used to indicate priority carry the symbol "1", while the other tones carry the symbol "0".

[0076]

[0137] When transmitting, an FD device cannot distinguish between prioritized FD preambles received simultaneously from itself or a colliding STA if the received prioritized FD preamble indicates a priority on a subcarrier and / or tone that is within 40 ppm of the subcarrier and / or tone carrying the FD device's own priority. Therefore, different priorities should be carried on different subcarriers and / or tones of the FD preamble, spaced at least 40 ppm apart. A larger spacing of more than 40 ppm between subcarriers carrying priority information allows for detection of different priorities, even in the presence of CFO. Subcarriers and / or tones are predetermined to represent specific priorities.

[0077]

[0138] A STA transmitting its own prioritized FD preamble can detect a collision from the received FD preamble by nulling out the self-interference of its own priority signal using analog SIC. If the STA detects another priority signal after the zeroing out is performed, a collision is detected.

[0078]

[0139] Priority tones interleaved in the prioritized preamble may not be understood by legacy devices.

[0079] 6.1.2.1 Prioritized FD Preamble Symbols in Frequency

[0141] FIG. 15 illustrates an example embodiment 230 of a preamble field 232 and an FD preamble 234 in the time and frequency domains. The preamble field may be the same as the preamble specified in the 802.11 Baseline Protocol. The FD preamble field immediately follows the preamble field and is used to convey a specific priority. Different priorities (illustrated as 236a, 236b, 236c, and 236d) may be indicated on different subcarriers of the FD preamble over a given interval (i.e., at least 40 ppm). By way of example and not limitation, there are three priorities shown in the figure. Note that the number of priorities is predetermined and agreed upon by the STAs applying this type of preamble.

[0080] 6.1.2.2. Example 1-2: CD using frequency orthogonal signals indicating different priorities

[0143] Figure 16 illustrates an example embodiment 240 of frequency-domain collision between different prioritized preambles. This figure shows preamble 242 and FD preamble 243 as seen in Figure 15. This example is based on the same topology as described in Figure 11. Assume that FD STA1 transmits a PPDU including preambles indicating priority 0 244a and 246a, while simultaneously, an interfering FD AP transmits a PPDU including preambles indicating priority 1 244b and 246b. As shown in the time domain, the two preambles from FD STA1 and the FD AP are transmitted almost simultaneously. As a result, a collision may occur on FD STA2.

[0081]

[0144] After the FFT, FD STA1, indicating a priority equal to zero, zeros out pulses associated with priority 0 transmissions 244a and 246a carried by the priority 0 tone, along with a portion of the spurious signal that is on the priority 0 tone but is from an interfering preamble that indicates priority 1 (after analog SIC). FD STA1 can then detect a peak in the priority 1 signal that indicates the presence of a colliding preamble with a different priority (priority 1) corresponding to tones 244b and 246b.

[0082]

[0145] The FD AP may also perform the same action as FD STA1 to detect a colliding preamble with a different priority (priority 0). Then, FD STA1 with a lower priority (e.g., priority 0) should stop transmitting and begin backoff. In this description, it is assumed that priority 0 refers to a priority lower than priority 1. The FD AP with a higher priority (e.g., priority 1) may retransmit to allow the intended receiver to resynchronize and estimate the channel.

[0083] 6.1.2.3. Example 1-3: CD using frequency orthogonal signals showing the same priority

[0147] Figure 17 illustrates an example embodiment 250 of a collision between frequency-domain preambles indicating the same priority. This example is also based on the same topology as described in Figure 11. Assume that FD STA1 transmits a PPDU containing preambles indicating priority 0 252a and 254a. At the same time, an interfering FD AP may transmit a PPDU containing preambles 252b and 254b, also indicating priority 0, causing a collision on FD STA2.

[0084]

[0148] After the FFT, the FD STA1 (indicating priority=0) zeros the pulses carried by the priority 0 tone (after the analog SIC) and the following is performed:

[0085]

[0149] (a) FD STA1 may also zero out interference priority 0 pulses from STA2 due to a very small CFO of less than 40 ppm. In this case, STA1 should not stop transmitting because STA1 cannot distinguish whether the peak in the priority 0 tone received before the SIC was caused by a colliding preamble or whether STA1's own transmitted preamble experienced Doppler effects as described in the Doppler effect case. Therefore, collisions may occur on FD STA2, and further collision resolution solutions to address this type of collision problem will be described in another section.

[0086]

[0150] (b) If the CFO is large (e.g., greater than 40 ppm), FD STA1 can detect an interference peak from the FD AP, thereby recognizing that the interference peak indicates the presence of a colliding preamble with the same priority (priority 0). In this case, FD STA1 stops transmitting and performs backoff when the channel is idle again. The FD AP performs the same as described for FD STA1.

[0087]

[0151] Note some aspects with respect to the diagram: In the case of the Doppler effect, STA1 transmits a PPDU including a preamble that still indicates priority 0, and there are no other interfering STAs. When considering the Doppler effect, STA1 may still receive a peak pulse on another tone (different from the tone indicating priority=0), which is a reflected signal of its own transmission.

[0088]

[0152] Since the speed of the STA or the obstacles reflecting the signal is usually quite small compared to the speed of the radio waves, the received peak pulse is likely to have the same priority tone as the transmitted tone. The frequency change between the received and emitted frequencies is TIFF0007733137000010.tif6170, where f0 is the emission frequency and c is the propagation speed of radio waves (approximately TIFF0007733137000011.tif6150m / sec).

[0089] 6.1.2.4. Examples 1-4: CD between prioritized and legacy preambles

[0154] 18 and 19 show an example embodiment 260 that includes a different topology 270.

[0090]

[0155] As can be seen in FIG. 19, FD AP 272 is receiving from both FD STA1 274 and half-duplex STA2 276.

[0091]

[0156] 18 shows a preamble 252, an FD preamble 254, and a legacy preamble 253. Assume that FD STA1 transmits a PPDU to the FD AP including prioritized preambles 256a and 256b indicating priority with a priority 0 tone. At the same time, an interfering non-FD STA2 transmits a PPDU to the FD AP including a legacy preamble, which may cause a collision on the FD AP.

[0092]

[0157] Note that the legacy preamble uses the preamble frame format as specified in the 802.11 standard, which does not include subcarriers / tones for containing priority information.

[0093]

[0158] After the FFT window 258, FD STA1 (indicating priority=0) zeros its pulses carried by the priority tones (after the analog SIC). FD STA1 is unable to detect peaks indicating any of the predetermined preambles. However, FD STA1 detects the presence of a collision signal. FD STA1 stops transmitting and performs backoff when the channel is idle. Non-FD STA2 detects the collision using legacy CSMA / CD techniques.

[0094]

[0159] 20 illustrates an example embodiment 280 in which a transmitting station (which may be an FD non-AP STA or an FD AP) reacts to the detection of a collision. A check (282) determines the priority level of the colliding FD preamble. If the condition is met, a check is made in block 284 to determine whether the detected priority is lower than the priority of the detecting station. If the condition is met, a retransmission (286) is performed.

[0095]

[0160] Returning to block 282, when the condition is not met, execution proceeds to block 290 to determine whether an FD preamble collision has occurred. If no collision has occurred, then in block 288 the transmitting STA continues transmitting the remainder of the PPDU.

[0096]

[0161] On the other hand, if the conditions of block 290 are met, execution proceeds to block 292, at which time the STA stops transmitting and begins backing off when the channel is idle.

[0097] 6.2. Conflict Resolution for Prioritized FDs

[0163] A problem can arise when the FD AP needs to prioritize high-priority traffic over lower-priority traffic: collisions occur at the destination non-AP STA of the DL traffic because both sets of traffic are using the channel simultaneously and the destination non-AP STA for the DL traffic and the source non-AP STA for the UL traffic are different.

[0098] Topology for the problem in Section 6.2.1.6.2

[0165] 21 illustrates an example topology embodiment 300 showing FD AP 302 receiving low priority traffic from FD STA1 304 and transmitting high priority traffic to FD STA2 306. FD STA1, FD STA2, and the FD AP are within communication range of each other, with the AP intending to transmit high priority traffic to STA2 and STA1 intending to transmit low priority traffic to the AP.

[0099]

[0166] FD STA1 sends a request to send (RTS) to the FD AP, and at the same time, the FD AP sends an RTS to FD STA2. A collision occurs on FD STA2, and as a result, the FD AP can receive the RTS from FD STA1 but does not receive the CTS from FD STA2.

[0100] Solution for the problem in Section 6.2.2.6.2

[0168] A prioritized collision avoidance scheme is described below. (1) An FD device can indicate a priority in a control frame used for collision avoidance. (2) If an FD device transmits a prioritized frame and receives another prioritized frame during transmission, the FD device recognizes that intra-BSS interference exists and should address the highly prioritized traffic first. (3) An FD device that estimates intra-BSS interference as described in item (2) can broadcast a frame indicating the priority that the FD device should process first. (a) After receiving a frame indicating the requested traffic priority, an FD device transmitting low-priority traffic suspends (stops) any transmission / retransmission. (b) An FD device transmitting high-priority or equal-priority traffic should continue the (re)transmission process. (4) An FD AP can trigger non-AP FD devices to start transmitting low-prioritized traffic. A non-AP FD device with low-prioritized traffic can re-access the channel without being triggered if the channel is idle for at least a PIFS duration after receiving a broadcast frame indicating that high-prioritized traffic is prioritized.

[0101]

[0169] If an FD device directly transmits a DATA PPDU instead of an RTS, it can use the simultaneously transmitted FD preamble and the received FD preamble to estimate an intra-BSS collision and determine the following process based on priority resolution: (a) An FD device that estimates the existence of an intra-BSS collision with a lower priority than itself should retransmit the PPDU. It can reserve a portion of resource units (RUs) for purposes other than DATA PPDUs, specifically for exchanging control messages between the AP and other STAs. (b) An FD device that estimates the existence of an intra-BSS collision with a higher priority than itself is configured to stop transmitting the remaining portion of the PPDU unless it receives a control frame (such as a trigger from the destination) from the reserved RU or a non-reserved RU. If this STA fails to receive any other frame exchanges between other STAs, it can re-access the channel after EDCA backoff when CCA is idle. (c) An FD device that receives only the preamble without the remainder of the DATA PPDU can transmit a control frame using a reserved RU (which can be, for example, a predetermined RU) to indicate the existence of an overestimated intra-BSS collision. If the preamble source STA receives this control frame through the reserved RU, it can retransmit or trigger (through the reserved RU) to retransmit the previously aborted PPDU that was overestimated as an intra-BSS collision signal.

[0102] 6.2-1. Example 2-1: Allowing HP traffic including PR+CDP frames

[0171] 22 shows an example embodiment 310 of FD AP 312 with high priority (HP), FD STA1 314 with low priority (LP), and FD STA2 316. Assume STA1 and STA2 can hear each other and start the process with RTS / CTS.

[0103]

[0172] The topology is the same as that seen in Figure 21. The FD AP has high priority (HP) traffic to transmit to FD STA2, and FD STA1 has low priority (LP) traffic to transmit to the FD AP. The FD AP, FD STA1, and FD STA2 are within communication range of each other (e.g., can hear each other). The FD AP and FD STAs each initiate a transmit opportunity (TXOP) containing a prioritized control frame, e.g., prioritized RTS (P-RTS) 318 and 319.

[0104]

[0173] (1) The AP receives a P-RTS (319) from STA1 (low priority traffic) and simultaneously transmits a P-RTS (318) to STA2 (high priority traffic).

[0105]

[0174] (2) The AP broadcasts a new frame (320) containing a priority request plus collision detection probability (PR+CDP) to declare its request for high priority data (DATA) transmission. Thus, the AP can indicate the collision detection probability in the new (PR+CDP) frame.

[0106]

[0175] (3) After receiving the broadcasted PR+CDP frame (320), STA1 realizes that it does not meet the priority requirement and therefore cancels the retransmission of the P-RTS after the P-CTS timeout that starts from the time STA1 transmitted the previous P-RTS.

[0107]

[0176] (4) If the AP does not receive a P-CTS from STA2 before the P-CTS timeout, which is the period that begins when the AP starts transmitting the previous P-RTS, the AP should retransmit another P-RTS (322) to STA2. Note that the transmission time of the PR+CDP frame should not be longer than the P-CTS timeout. If the transmission time of the PR+CDP frame is longer than the P-CTS timeout, the AP should retransmit the P-RTS a SIFS period after the AP sends the PR+CDP frame.

[0108]

[0177] (5) STA2 receives the retransmitted P-RTS from the AP and responds to the AP with a P-CTS (324). The AP sends a PPDU (326) to STA2 with Ack / BA (328) and (330).

[0109]

[0178] (6) As can be seen in the figure, STA1 is CCA busy (323) and will not access the channel to (re)transmit the PPDU unless STA1 receives a trigger from the AP to allow it to access the channel again.

[0110]

[0179] Next, in the remainder of the figure, the AP triggers the STA (334), which accesses the channel and transmits a PPDU (338), which is acknowledged (340) (342).

[0111] 6.2-1-0. Example 2-1-0: FD AP triggers LP traffic without receiving any response from authorized HP traffic destination

[0181] Figure 23 shows an example embodiment 410 which is a variation of that shown in Figure 22. The description is the same as in Example 2-1. The first four bullet points of this example are the same as those described in Example 2-1, and here the differences start from the fifth element.

[0112]

[0182] (5) STA2 fails to receive the retransmitted P-RTS (322) from the AP and therefore does not respond to the AP with a P-CTS.

[0113]

[0183] (6) Since the AP did not receive a P-CTS from STA2 after the P-RTS retransmission, it sends a trigger frame (412) to STA1 to allow STA1 to access the channel.

[0114]

[0184] (7) STA1 receives a trigger frame from the AP, transmits a UL PPDU (418) to the AP, and receives an Ack / BA (420) from the AP during transmission of the UL PPDU.

[0115]

[0185] (8) After acknowledging (422) all UL PPDUs from STA1, the AP can retransmit P-RTS (424) to STA2. STA1 goes CCA Busy (426).

[0116]

[0186] (9) STA2 successfully receives the P-RTS from the AP and responds to the AP with a P-CTS (428).

[0117]

[0187] (10) After receiving the P-CTS from STA 2, the AP transmits a DL PPDU (430) to STA 2. The AP can receive an Ack / BA (432) from STA 2 during the transmission of the DL PPDU.

[0118]

[0188] (11) STA2 should acknowledge (434) all received DL PPDUs to the AP.

[0119] 6.2-1-1. Example 2-1-1: FD STA1 re-accesses the channel without receiving a trigger from the FD AP

[0190] 24 shows an example embodiment 510 with the same topology and description as Example 2-1. The first four bullet points are the same as those described in Example 2-1, and the following steps begin from there.

[0120]

[0191] (5) STA2 fails to receive the retransmitted P-RTS (322) from the AP and therefore does not respond to the AP with a P-CTS.

[0121]

[0192] (6) The AP does not receive a P-CTS from STA2 after the P-RTS retransmission, and therefore does not send a trigger frame to STA1 that allows STA1 to access the channel.

[0122]

[0193] (7) STA1 is CCA busy (512) during a P-RTS. STA1 then regains access to the channel when it detects CCA idle, for example, by sending a CTS to itself, sending a retransmitted P-RTS to the AP, or sending UL DATA after receiving a trigger frame from the AP. In this example, STA1 sends a retransmitted P-RTS (514) to the AP, and STA2 is CCA busy (516), as shown in the figure.

[0123]

[0194] (8) The AP receives the P-RTS from STA1 and responds with a P-CTS (518) to STA1 to allow STA1 to send the LP UL PPDU.

[0124]

[0195] (9) STA1 receives a P-CTS frame from the AP, transmits a UL PPDU (520) to the AP, and then receives an Ack / BA (522) from the AP during transmission of the UL PPDU.

[0125]

[0196] (10) After acknowledging (524) all UL PPDUs (520) from STA1, the AP can retransmit the P-RTS (526) to STA2.

[0126]

[0197] (11) STA2 successfully receives the P-RTS from the AP and responds to the AP with a P-CTS (530).

[0127]

[0198] (12) After receiving P-CTS from STA2, the AP transmits DL PPDU (532) to STA2. The AP can receive Ack / BA (534) from STA2 during the transmission of DL PPDU.

[0128]

[0199] (13) STA2 should acknowledge (536) all received DL PPDUs to the AP.

[0129] 6.2-2-1-2. Example 2-1-2: Allowing HP traffic that does not include PR+CDP frames

[0201] 25 illustrates an example embodiment 610 of Example 2-1-2 of admitting HP traffic without PR+CDP frames. In this example, if both the AP and STA1 are pre-configured to estimate intra-BSS collisions and admit highly prioritized traffic, the AP and STA1 can perform the following after priority resolution from the collision preamble:

[0130]

[0202] In the FD AP: (a) the AP (high priority) sends a P-RTS (318) to STA2 and simultaneously receives a P-RTS (319) from STA1 (low priority). (b) After priority resolution of the received preamble, the AP decides to continue transmitting highly prioritized traffic. Instead of sending a P-CTS in response to the P-RTS received from FD STA1 (low priority), the AP (high priority) retransmits a P-RTS (612) to STA2. At this time, STA1 is CCA busy (614). Upon receiving a P-CTS (616) from STA2, the AP transmits a PPDU (618), to which STA2 responds with acknowledgments (620) and (622). After this, the AP sends a trigger (624) to STA1, which responds with a PPDU (626), to which the AP acknowledges (628) (630), while STA2 is CCA busy (625).

[0131]

[0203] In FD STA1: (a) STA1 (low priority) sends a P-RTS (319) to the AP and simultaneously receives a P-RTS (318) from the AP (high priority). (b) After priority resolution based on the received preamble, STA1 stops transmitting to avoid colliding with highly prioritized traffic and becomes CCA busy (614). (c) STA1 receives a trigger (624) from the AP (high priority) and sends a PPDU (626), which is acknowledged (628) (630) when received, all the while STA2 is CCA busy (625).

[0132] 6.2-2-2 Example 2-2: Home Page Traffic Admission When AP Has LP

[0205] 26 and 27 show an example embodiment 710 and an example topology 750 for admitting high priority traffic when an AP has low priority traffic.

[0133]

[0206] In Figure 27, the topology is almost the same as in Figure 21, with the difference being that the traffic priorities are swapped, with FD AP having LP traffic to FD STA2 and FD STA1 having HP traffic to the AP.

[0134]

[0207] Referring to FIG. 26, the stations are within range of each other and the FD AP and FD STA initiate a TXOP containing a prioritized control frame, exemplified by a prioritized RTS (P-RTS).

[0135]

[0208] (1) FD STA1 transmits a P-RTS (319) (HP) to the FD AP, and at the same time, the FD AP transmits a P-RTS (318) to FD STA2 (LP). If FD STA1 and FD STA2 are within each other's communication range, the P-RTS frames may collide at FD STA2.

[0136]

[0209] (2) The FD AP first responds to STA1 (HP) with a P-CTS (712) and pauses retransmission of the P-RTS to STA2, which is CCA busy (714) at the time.

[0137]

[0210] (3) After receiving P-CTS from the AP, STA1 transmits a UL PPDU (716) and receives Ack (718) and (720) in response.

[0138]

[0211] (4) After completing the transmission sequence with the STA, the AP retransmits a P-RTS (722) to STA2. At this time, STA1 is CCA busy (724).

[0139]

[0212] (5) After receiving P-RTS (722) from AP1, STA2 responds with P-CTS (726).

[0140]

[0213] (6) After receiving P-CTS from STA2, AP1 transmits DL PPDU (728) to STA2 and receives Ack (730) and (732) in response.

[0141] 6.2-2-3 Example 2-3: Allowing Home Page Traffic When an AP Has an LP

[0215] 28 and 29 show example topographies 790 and 810 used to illustrate the effect of other basic service set (OBSS) collisions. As shown in Examples 2-1-1, 2-1-2, and 2-2, the AP should allow transmission of highly prioritized traffic after performing collision resolution. However, OBSS interference may cause a collision, and the AP does not receive the colliding frame.

[0142]

[0216] In Figure 28, FD AP1 802 estimates the presence of OBSS interference. FD STA1 800 and FD STA2 798 are associated with FD AP1 802, which is an OBSS AP that may generate OBSS interference, as illustrated by signals 794 and 796. FD AP1 802 is sending high priority traffic (HP) 804 to STA2 798.

[0143]

[0217] At the same time that FD AP1 is sending high-priority traffic (804) to FD STA2, OBSS AP2 is sending some frames in the OBSS. The high-priority traffic frame from FD AP1 and the interference (794) frame from FD AP2 collide at FD AP2. AP1 does not receive the interference frame from OBSS AP2 and cannot deduce the existence of a collision during the sending of the high-priority traffic frame. In this case, FD AP1 should retransmit the frame based on the legacy retransmission policy.

[0144]

[0218] In Figure 29, an AP estimates the presence of intra-BSS interference. The topology and BSS interference are similar to Figure 28, but in this example, FD AP1 812 is sending the same HP traffic (814) to FD STA2 798, but in this example, FD STA1 800 is also sending a low priority traffic frame (816) to FD AP1 812.

[0145]

[0219] As a result of the above, a collision caused by intra-BSS interference and OBSS interference occurs on FD STA2 798. In this case, FD AP1 can only infer the existence of an intra-BSS collision by receiving a collision preamble indicating low priority during transmission.

[0146]

[0220] Although FD AP1 cannot deduce the existence of an OBSS collision, it should still process the proposed protocol and allow the transmission of highly prioritized traffic after collision resolution is performed.

[0147] 6.2-2-4 Example 2-4: AP overestimates collisions

[0222] FIG. 30 illustrates example cases 850a, 850b, 850c, and 850d in which an AP may overestimate a collision. These cases represent different scenarios combining an FD AP 854 with one or more stations, such as FD STA1 852, FD STA2 856, and FD STA3 858. The AP may also overestimate an intra-BSS collision, as shown in Case 2 (850b) and Case 4 (850d), in which FD STA1 and FD STA2 are out of communication range of each other. However, the AP does not know (e.g., has no information indicating) that FD STA1 and FD STA2 cannot hear (communicate with) each other. Thus, in these two cases, the AP may estimate that a collision exists within the BSS, but no collision exists due to the two stations being out of range of each other. Therefore, the AP is said to have overestimated a collision.

[0148]

[0223] In case 1 (850a), when the AP is transmitting to FD STA1 and FD STA1 is also transmitting to the AP, the AP may detect a fake collision. However, the FD AP cannot recognize that the received PPDU is intended for itself without decoding the receiver address indicated in the header of the received PPDU. When the AP detects the presence of an interfering preamble, it stops transmitting. However, in reality, there is no collision within the BSS.

[0149]

[0224] In case 3 (850c), the AP can detect a collision when it is transmitting to FD STA1 while FD STA1 is transmitting to FD STA2. The AP can avoid the collision on FD STA2 by listening (detecting) the interfering preamble and ceasing transmission.

[0150]

[0225] In the following section we describe a solution using PR+CDP frames that is designed to overcome the problem of overestimated collisions.

[0151]

[0226] 31 illustrates an example embodiment 910 that resolves the example overestimated collision case 2 of FIG. 30, where the FD AP has high priority (HP) traffic to FD STA2 and FD STA1 has low priority (LP) traffic to the FD AP. FD STA1 and FD STA2 are not within communication range of each other, but both can communicate with the FD AP. The FD AP and FD STA initiate a TXOP that includes a prioritized control frame, e.g., a prioritized RTS (P-RTS).

[0152]

[0227] (1) The AP receives a P-RTS (319) from STA1 (low priority) and simultaneously transmits a P-RTS (318) to STA2 (high priority).

[0153]

[0228] (2) The AP broadcasts a new frame (PR+CDP) (912) to declare its request for high priority data (DATA) transmission (including indicating the priority level). (i) The AP can indicate the collision probability in the new (PR+CDP) frame.

[0154]

[0229] (3) STA1 and STA2 are out of communication range of each other, which means there is no P-RTS collision as described in the above step. STA2 responds to the P-RTS sent by the AP with a P-CTS (914), which overlaps in time with the PR+CDP frame received from the AP.

[0155]

[0230] (4) The P-CTS from STA2 collides with the PR+CDP frame from the AP on STA1, but the P-CTS can be received by the AP when the AP is transmitting the PR+CDP frame.

[0156]

[0231] (5) After receiving the P-CTS (914) from STA2, the AP recognizes that it overestimated the intra-BSS collision and should respond with a P-CTS to the P-RTS it previously received from STA1.

[0157]

[0232] (6) STA1 should retransmit the P-RTS to the AP after the first P-CTS timeout because it did not receive the PR+CDP frame (912). The P-RTS retransmitted to the AP may overlap in time with the P-CTS received from the AP and may not have start / end point alignment. In this case, STA1 does not retransmit the P-RTS again.

[0158]

[0233] (7) Both STA1 and the AP receive the P-CTS from their destination and begin transmitting one or more PPDUs (924), (925), (932), (933) to the destination at the same time that the start and end points of each PPDU are aligned.

[0159]

[0234] (8) PPDU start time alignment (922) and (930) can be achieved as follows: (a) based on a predetermined time + SIFS after the AP (collision estimator) transmits the first P-RTS to transmit a P-CTS to STA1 (overestimated collidator); (b) alignment information can be transmitted, e.g., the PPDU start time can be defined in the PR+CDP frame.

[0160]

[0235] (9) PPDU length alignment (922) and (930) can be achieved as follows: (a) indicated in the first P-RTS; (b) indicated in the PR+CDP frame; (c) indicated in management frames exchanged between the AP and the STA.

[0161]

[0236] (10) The AP and STA2 receive PPDUs (924), (925), (932), and (933) and respond with Ack / BA (928), (929), (936), and (937) simultaneously with aligning the start and end points of the Ack / BA (926) and (934). (a) When an FD STA is transmitting a PPDU, it can receive another PPDU at the same time. In this case, an Ack / BA should not be scheduled when the STA is transmitting a PPDU. There are several ways to achieve this: (i) Send a BA request at the end of each PPDU transmission; or Send a BA-only response after receiving a BA request; or (ii) Configure this in the first P-RTS frame, PR+CDP frame, or other management frame exchanged between the AP and STA for reconfiguration.

[0162]

[0237] Next, as shown in this figure, the AP transmits a PPDU (938) to STA2, while STA1 is CCA busy (940) and returns an Ack (942) to the AP.

[0163]

[0238] 32 to 35 show an example embodiment 950 of the operation of the FD AP when a TXOP including a combination of P-RTS and P-CTS is initiated.

[0164]

[0239] 32, a set of checks are performed to determine whether a P-RTS containing priority was sent (952), whether a concurrent P-RTS was received (954), whether a P-RTS for intra-BSS collision estimation has a low priority (956), whether a PR+CDP was broadcast (958), and whether an intra-BSS collision was overestimated (960). If all of these conditions are met, the AP responds with a P-CTS to the low-priority traffic source in block 962.

[0165]

[0240] If the check (960) indicates that the collision was not overestimated, then in block 964 of FIG. 33, the AP retransmits (964) the P-RTS with the indicated priority and completes (966) the TX / RX sequence for the high priority traffic.

[0166]

[0241] A check (968) then determines whether the frame should be sent to the low priority traffic source. If the frame should not be sent, the process ends. On the other hand, if it is determined that the frame should be sent, the low priority traffic sequence is completed in block 970, and the process then ends.

[0167]

[0242] Returning to first decision block 952 of Figure 32, if the condition is not met, execution proceeds to block 988 of Figure 35 to determine whether a P-RTS was received. If a P-RTS was received, the AP responds (990) with a P-CTS, and the AP receives one or more PPDUs and a Block Ack Request (BAR) (992), responds with an Ack / BA, and then terminates the process. If block 988 determines that a P-RTS was not received, the process also terminates.

[0168]

[0243] Returning to the second decision block 954 of Figure 32, if the condition is not met, execution proceeds to block 976 of Figure 34, where a check determines whether a P-CTS was received before the P-CTS timeout. If the condition is not met, a P-CTS timeout (984) is registered and a P-RTS is retransmitted (986), after which execution returns to begin at block 952 of Figure 32.

[0169]

[0244] On the other hand, if the conditions of block 976 are met, then in block 978 the AP transmits the PPDU and receives an Ack / BA (980), and then a check is made to determine if the TXOP has not yet expired and if more PPDUs are to be transmitted (982). If more PPDUs are to be transmitted, execution returns to block 978; otherwise, execution proceeds to block 966 of FIG. 33 to complete the high priority TX / RX sequence.

[0170]

[0245] Returning to the third decision block 956 of FIG. 32, if the condition is not met, then the AP responds with a P-CTS in block 974 of FIG. 34 and execution continues to block 966 of FIG.

[0171]

[0246] Returning to the fourth decision block 958 of FIG. 32, if the condition is not met, then the AP retransmits the P-RTS at block 986 of FIG. 34 and execution returns to the start of the process.

[0172]

[0247] Returning to the fifth decision block 960 of FIG. 32, if collisions are overestimated, in block 962 the AP responds with a P-CTS to the low priority traffic source, and execution proceeds to block 972 of FIG. 33, where both high priority and low priority traffic are processed simultaneously, executing blocks 966 and 970.

[0173]

[0248] 36 to 38 show the operation of the FD STA when a TXOP including a combination of P-RTS and P-CTS is initiated.

[0174]

[0249] In Figure 36, a series of checks determine whether a P-RTS has been sent (1012), whether a P-RTS has been received at the same time, presuming an intra-BSS collision (1014), and whether a PR+CDP frame has been received (1016).

[0175]

[0250] If all these conditions are met, in block 1018, the STA stops retransmitting the P-RTS and execution proceeds to block 1022 of FIG. 37, where it checks whether a higher priority P-RTS or P-CTS or data (DATA) has been transmitted within a short interval (e.g., a PIFS time period after stopping the (re)transmission).

[0176]

[0251] If the condition is not met, then in block 1024 the STA uses CCA to send a frame to the same destination as the previously transmitted P-RTS to request processing of the subsequent transmission.

[0177]

[0252] If the condition of block 1022 is met, the STA stops its transmission or retransmission in block 1032. In either case, execution proceeds to check (1026) to determine whether a frame has been received to trigger and / or initiate PPDU transmission. If the condition is met, in block 1028, the STA completes its TX / RX sequence and ends the process.

[0178]

[0253] If the condition of the check (1026) is not met, a response frame timeout is registered in block 1030 and execution returns to block 1022.

[0179]

[0254] Returning to block 1012 of FIG. 36, when the condition is not met, execution proceeds to block 1046 of FIG. 38, which determines whether the STA received a P-RTS that includes priority information.

[0180]

[0255] If the condition is not met, the process ends.

[0181]

[0256] If the conditions of block 1046 are met, then in block 1048 the STA responds with a P-CTS, and then in block 1050 the STA receives one or more PPDUs and BARs and responds with an Ack / BA, ending the process.

[0182]

[0257] Returning to check 1014, if the condition is not met, check 1034 of Figure 38 determines whether the STA received a P-CTS before the P-CTS timeout. If not received in time, a timeout is registered in block 1042, and the STA retransmits 1044 a P-RTS including priority information, and execution continues to block 1012 of Figure 36.

[0183]

[0258] On the other hand, if the condition is met in check (1034), then in block 1036 the STA transmits the PPDU and receives an Ack / BA (1038). A check (1040) then determines if the TXOP is still active (not expired) and if any more PPDUs need to be sent. If the condition is met, execution returns to block 1036. Otherwise, the TXOP has expired and the process ends.

[0184]

[0259] Returning to check (1016) in Figure 36, when the condition is not met, execution proceeds to block 1020, which determines whether the STA received a P-RTS frame indicating higher or equal priority. If the condition is not met, execution proceeds to check (1026) in Figure 37.

[0185] 6.2-3-1 Example 3-1: HP Traffic Admission for TXOP Initiated by PPDU

[0261] The topology for this example is shown in Figure 21. FD AP 312 has high priority (HP) traffic to FD STA2 316, and FD STA1 314 has low priority (LP) traffic to the FD AP. The FD AP, FD STA1, and FD STA2 are within communication range of each other. The FD AP and FD STAs initiate a TXOP containing a PPDU.

[0186]

[0262] (1) First, STA1 (low priority) sends a preamble (1114) to its associated AP to indicate the priority of its traffic. At the same time, the AP (high priority) also sends a preamble (1112) to STA2 to indicate the priority of its traffic.

[0187]

[0263] (2) Both AP and STA1 assume that an intra-BSS collision may exist since each transmits its own preamble and receives the other's preamble at approximately the same time.

[0188]

[0264] (3) After STA1 estimates an intra-BSS collision, it stops transmitting the remainder of the PPDU to the AP and is CCA busy as shown (1120). STA1 waits to sense the channel or waits for a response or trigger frame from the AP before performing its next transmission.

[0189]

[0265] (4) After the AP estimates an intra-BSS collision, if the colliding preamble indicates a lower priority than the AP's traffic, the AP can immediately retransmit the PPDU (1122) or alternatively retransmit the PIFS after receiving the colliding preamble.

[0190]

[0266] (5) The AP may reserve some RUs (represented by the shaded area at the bottom of the PPDU block) to send selection control messages to other STAs that are not the destination of the current PPDU frame. If the collision preamble indicates a higher priority than the AP's traffic, the process is carried out as described in Examples 3-3 and 3-4 in the following sections.

[0191]

[0267] (6) STA2 receives a DL PPDU (1122) from the AP and can respond to the AP with Ack / BA (1124), (1126) during the reception. The time to respond with Ack / BA should follow a schedule (if any) that can be set in a BAR or other control / management frame.

[0192]

[0268] (7) After / during the retransmission of the PPDU, the AP does not receive an Ack / BA from STA2 and can send a trigger frame (1128) to STA1 to allow STA1 to access the channel.

[0193]

[0269] (8) STA1 does not receive a PPDU from the AP, nor does it receive one from STA2. STA2 can either regain access to the channel after EDCA backoff by sending the AP, for example, a control frame or a retransmitted PPDU, containing a destination to the AP, or wait for a trigger frame from the AP to start transmitting the TB-PPDU.

[0194]

[0270] (9) STA1 detects CCA busy (1120) and therefore waits to access the channel to (re)transmit the PPDU unless it receives a trigger from the AP to allow STA1 to access the channel.

[0195]

[0271] In the figure, during PPDU 1122, STA2 sends ACKs 1124 and 1126. The AP sends a trigger 1128 to STA1. STA1 sends a preamble (LP) 1132 and a PPDU 1134. The AP responds to STA1 with Acks 1136 and 1138, all the while STA2 is CCA busy 1130.

[0196] 6.2-3-2 Example 3-2: Admitting HP Traffic with Overestimated Intra-BSS Collisions

[0273] 40 shows an example embodiment 1210 where the AP has high priority (HP) and STA1 has low priority (LP). STA1 and STA2 are not within communication range. Begin the process involving a DATA PPDU.

[0197]

[0274] (1) First, STA1 (low priority) sends a preamble (1214) to its associated AP to indicate the priority of its traffic. At the same time, the AP (high priority) also sends a preamble (1212) to STA2 to indicate the priority of its traffic.

[0198]

[0275] (2) Both AP and STA1 transmit their own preambles and simultaneously receive preambles from other STAs, and then estimate that there may be intra-BSS collisions. However, both AP and STA1 overestimate the intra-BSS collisions.

[0199]

[0276] (3) After estimating an intra-BSS collision, STA1 stops transmitting the remainder of the PPDU to the AP and recognizes that there is a collision preamble indicating traffic of higher priority than STA1's priority. STA1 should wait to sense the channel or wait for the AP's response or trigger frame (1222) before performing its next transmission.

[0200]

[0277] (4) After the AP estimates an intra-BSS collision, if the collision preamble indicates a lower priority than the AP's traffic, the AP can immediately retransmit the PPDU to STA2 (1220) or possibly retransmit the PIFS after receiving the collision preamble. The AP can reserve some RUs (shown in the shaded portion of the PPDU) to send control messages to some other STAs that are different from the destination of the ongoing transmission PPDU.

[0201]

[0278] (5) Because there is no collision on STA2, STA2 receives the preamble from the AP but does not receive the remainder of the DATA PPDU. Later, STA2 receives a retransmitted PPDU containing the same preamble. In this case, STA2 can use the reserved RUs (1218) and (1222) to send a control frame such as a CTS to the PPDU source, which can be an immediate response or SIFS after receiving the preamble.

[0202]

[0279] (6) The AP receives a control frame (1218) from STA2 in the reserved RU, during which the AP may be transmitting a DL PPDU to STA2. The AP may then use the reserved RU to transmit a trigger frame (e.g., PR+CDP) to STA1 to trigger the preamble (1224) containing the UL PPDU (1226) from STA1. Note that the trigger frame contains PPDU end point alignment information, and the end points of the TB PPDU from STA1 to the AP and the UL PPDU from the AP to STA2 should be aligned.

[0203]

[0280] (7) STA1 receives a control frame from the AP in the reserved RU and triggers an UL PPDU (1220). STA1 should transmit UL PPDUs (1224) and (1226) according to the PPDU end point alignment (1225) rule from the received control frame.

[0204]

[0281] (8) The AP and STA2 should receive the PPDUs (1220), (1226) and respond with Ack / BA (1230) and (1231) simultaneously with aligning the start and end points of the Ack / BA (1228). Ack / BA should not be scheduled when the STA is transmitting a PPDU. There are several ways to achieve this: (a) Send a BA request at the end of each PPDU transmission. The BA only responds after receiving the BA request. (b) Configure this in a control frame such as a PR+CDP frame or other management frame exchanged between the AP and STA for reconfiguration.

[0205]

[0282] This figure shows additional aligned PPDUs 1234, 1235 between the AP and STA2 (1232), followed by associated Acks 1238 and 1239 that are aligned 1236. This is followed by another PPDU 1240 sent to STA2, followed by an Ack 1246, while STA1 is CCA busy 1242, as shown.

[0206] 6.2-3-3 Example 3-3: HP Traffic Admission for TXOP Initiated by PPDU When AP Has LP

[0284] 41 shows an example embodiment 1310 of this Example 3-3 illustrating HP traffic admission for a PPDU initiated TXOP when the AP has low priority. The topology is shown as Case 2 in FIG.

[0207]

[0285] FD AP 312 has low priority (LP) traffic to transmit to FD STA2 316, while FD STA1 314 has high priority (HP) traffic to transmit to the FD AP. FD STA1 and FD STA2 are not within range of each other, but both are within communication range of the FD AP. The FD AP and FD STA initiate a TXOP containing a PPDU.

[0208]

[0286] (1) First, STA1 (high priority) sends a preamble (1314) to its associated AP to indicate the priority of its traffic. At the same time, the AP (low priority) also sends a preamble (1312) to STA2 to indicate the priority of its traffic.

[0209]

[0287] (2) Both the AP and STA1 assume that an intra-BSS collision may exist because they see their preambles being transmitted at the same time that their own preambles are received at the same time.

[0210]

[0288] (3) STA1 stops transmitting the PPDU (to avoid further potential collisions) after estimating an intra-BSS collision based on the simultaneously transmitted and received preambles. If STA1 has a higher priority, it can immediately retransmit a new preamble (1318) and PPDU (1322) to the AP, or retransmit the PPDU over a PIFS after receiving the colliding preamble. STA1 reserves some RUs (as shown in the shaded area of ​​the PPDU) to allow the AP to exchange control messages with other STAs.

[0211]

[0289] (4) After the AP estimates an intra-BSS collision, if the colliding preamble indicates a higher priority than the AP's traffic, the AP stops transmitting the remaining part of the PPDU.

[0212]

[0290] (5) The AP receives the UL PPDU (1322) from STA1 and can respond to STA1 with an Ack / BA (1324) during the reception. The time to respond with an Ack / BA should follow a schedule (if any) that can be set in a BAR or other control / management frame.

[0213]

[0291] (6) After completing the transmission sequence and receiving the UL PPDU from STA1, the AP accesses the channel again after EDCA backoff and sends a retransmitted preamble (1326) and PPDU (1330) to STA2, which is responded to by Ack / BA (1332) and (1334). During this time, STA1 is CCA busy.

[0214] 6.2-3-4 Example 3-4: HP Traffic Admission for TXOP Initiated by PPDU When AP Has LP

[0293] 42 shows an example embodiment 1410 including FD AP 312 with LP, FD STA1 314 with HP, and FD STA2 316. In this example, STA1 and STA2 are not within range of each other, but are within range of the AP. This example begins with a DATA PPDU.

[0215]

[0294] The topology is similar to that shown in Case 2 (850b) of Figure 30, with the only difference being that the AP has a LP to STA2 and STA1 has a HP to the AP. The FD AP has low priority (LP) traffic to FD STA2, and FD STA1 has high priority (HP) traffic to the FD AP. FD STA1 and FD STA2 cannot communicate with each other, but both can communicate with the FD AP. The FD AP and FD STA initiate a TXOP containing a PPDU.

[0216]

[0295] (1) First, STA1 (high priority) sends a preamble (1414) to its associated AP to indicate its traffic priority. At the same time, the AP (low priority) also sends a preamble (1412) to STA2 to indicate its traffic priority.

[0217]

[0296] (2) Both AP and STA1 estimate that an intra-BSS collision may exist because they transmit their own preambles and simultaneously receive preambles from other stations. However, in this case, both AP and STA1 overestimate the intra-BSS collision.

[0218]

[0297] (3) After the AP estimates an intra-BSS collision, if the collision preamble indicates a higher priority than the AP's traffic, the AP stops transmitting the remainder of the PPDU unless it receives a control frame from the reserved RU indicating that the AP has overestimated the intra-BSS collision.

[0219]

[0298] (4) After STA1 estimates an intra-BSS collision based on the transmitted and received preambles, it stops transmitting the remainder of the PPDU (1414) (to avoid the possibility of further collisions). If STA1 has a higher priority, it can immediately retransmit the preamble (1418) and PPDU (1426) or retransmit the PPDU over a PIFS after receiving the colliding preamble. STA1 reserves some RUs (as shown in the shaded portion of the PPDU) to allow the AP to exchange control messages with other STAs.

[0220]

[0299] (5) In this case, STA2 receives a preamble from the AP that does not contain the remainder of the DATA PPDU. If STA2 receives nothing and the channel is idle for another preamble duration plus possibly a PIFS interval, STA2 can send a control frame to the AP using a reserved RU, either immediately or with another SIFS delay, to indicate that it will receive the preamble.

[0221]

[0300] (6) The AP receives a control frame (1422) from STA2 in the reserved RU indicating that the AP overestimated the intra-BSS collision. The AP can retransmit the preamble (1424) and PPDU (1428) to STA2, the destination of the overestimated intra-BSS collision. The AP should transmit the DL PPDU to STA2 with a PPDU that has end-point alignment with the UL PPDU received from STA1.

[0222]

[0301] (7) The AP and STA2 should receive the PPDU and respond with Ack / BA (1430) and (1431) simultaneously to align the start and end of the Ack / BA. Ack / BA should not be scheduled when the STA is transmitting a PPDU. There are several ways to achieve this: (a) Send a BA request at the end of each PPDU transmission; Use a BA-only response after receiving a BA request (BAR); or (b) Configure this in a control frame such as a PR+CDP frame or other management frame exchanged between the AP and STA for reconfiguration.

[0223]

[0302] Next, the figure shows an additional PPDU including a preamble (1432) and a PPDU (1436) to STA2, and a preamble (1434) and a PPDU (1436) to the AP, followed by Acks (1438) and (1439).

[0224]

[0303] 43-45 show an example embodiment 1470 in which an FD STA initiates a TXOP containing a DATA PPDU. In a check 1472, the AP assumes that the intra-BSS collision has lower priority than the AP itself.

[0225]

[0304] 43, if the condition is met, the AP retransmits the PPDU containing the reservation of some RUs for other STAs in block 1474. Next, in check 1476, a check is made to determine whether the AP has received a control frame from the destination through the reserved RUs that indicates an overestimation of intra-BSS collisions.

[0226]

[0305] If the condition is met in block 1476, the AP transmits a control (trigger) frame in the reserved RU to trigger the presumed colliding STA to transmit a trigger-based PPDU (TB-PPDU) in block 1482 of Figure 44. Then, in block 1484, the AP maintains PPDU end and / or start alignment and Ack / BA alignment under the schedule (if any) and ends the process.

[0227]

[0306] Returning to check (1476), if the condition is not met, execution proceeds to block 1478 of Figure 44 to terminate the current PPDU transmission sequence and send a trigger to another STA that is presumed to be a lower priority colliding STA. Next, in block 1480, the AP transmits an Ack / BA in response to the received PPDU, ending the process.

[0228]

[0307] Returning to check (1472), if the condition is not met, execution proceeds to block 1486 of Figure 45, where the AP stops transmitting the remainder of the PPDU. Next, in check (1488), the AP determines whether it has received a control frame from the destination STA through the reserved RU indicating an overestimate of intra-BSS collisions.

[0229]

[0308] If the condition is met, then in block 1490, the AP retransmits the DL PPDU, during which time the AP can receive the UL PPDU, and execution proceeds to block 1484 of FIG.

[0230]

[0309] Returning to block 1488, if the condition is not met, in block 1492 the AP sends an Ack / BA in response to the received PPDU, and then in block 1494 the AP can end the current PPDU transmission sequence and send a trigger to other STAs that are estimated to be colliding STAs with lower priority, ending the process.

[0231]

[0310] 46 and 47 show an example embodiment 1510 in which a non-AP STA initiates a TXOP containing a DATA PPDU.

[0232]

[0311] A check (1512) determines whether the non-AP STA received a preamble that does not contain the remainder of the DATA PPDU. If this condition is met, in block 1520 the STA transmits a control frame using the reserved RU to indicate an overestimated intra-BSS collision, and then in block 1522 the non-AP STA transmits an Ack / BA in response to the PPDU, ending the process.

[0233]

[0312] Returning to check (1512), if the condition is not met, then in check (1514) the STA checks whether the intra-BSS collision estimate has a lower priority than the STA itself.

[0234]

[0313] If the condition is met, in block 1516, the STA retransmits the PPDU including reserving some RUs for other STAs, and in block 1518, the STA maintains PPDU end point and / or start point alignment and Ack / BA alignment under the schedule (if a schedule exists) and ends the process.

[0235]

[0314] Returning to check (1514), if the condition is not met, execution proceeds to block 1524 of Figure 47, where the STA stops transmitting the remainder of the PPDU. Check (1526) determines whether a control frame triggering an UL PPDU has been received from the destination STA (AP) through a reserved or unreserved RU.

[0236]

[0315] If the condition is not met, in block 1530, the STA retransmits the PPDU after EDCA backoff when the channel is CCA idle if it cannot receive a frame exchange between other STAs, and ends the process.

[0237]

[0316] If the condition is met, execution proceeds from check (1526) to block 1528, where the STA retransmits the UL PPDU, and then proceeds to block 1518 of FIG.

[0238] 7. Data Structures 7.1. Preamble with Priority

[0319] In the legacy preamble, there are several reserved bits. Returning to the FD training sequences in Figures 4 and 5, note the following: Bit 14 (B14) of the HE-SIG-A field of the HE SU PPDU and HE ER SU PPDU is reserved. Bit 7 (B7) of the HE-SIG-A field of the HE MU PPDU is reserved. In both cases, these reserved bits can be used to indicate priority High (stage 1) and priority Low (stage 0).

[0239]

[0320] In the following description, specific bit states for indicating conditions / information are provided by way of example and not limitation.

[0240]

[0321] Alternatively, the priority information can be implemented in the FD preamble following the legacy preamble as shown in Figure 5. The FD preamble field can include a priority subfield. Alternatively, different priorities can be embedded in different subcarriers at specific intervals (i.e., at least 40 ppm) on the tones corresponding to the bit range of the FD preamble field.

[0241] 7.2.P-RTS (Prioritized RTS)

[0323] Figure 48 shows an example P-RTS frame 1590. An FD STA can initiate a TXOP by sending a P-RTS frame, which indicates the priority of the traffic the transmitting STA requests to transmit and any scheduling information, such as PPDU alignment. STAs receiving a P-RTS frame should be aware of the required traffic priority and should follow the PPDU and / or Ack alignment rules as requested in this frame. The Frame Control indicates frame control information corresponding to different frame types. The Duration / ID field sets a NAV value at the receiving STA that protects until the end of any subsequent Data, Management, or Response frames plus any additional overhead frames in single protection. Otherwise, the Duration / ID field sets a NAV that protects until the estimated end of the sequence of multiple frames in multiple protection.

[0242]

[0324] The RA field of this frame is the address of the STA that is the intended direct recipient. The TA field is the address of the STA that sends this frame. The Priority field indicates the priority specified in the RTS frame. The FCS field for error detection contains a 32-bit CRC. The PR control field indicates priority request information and corresponding control information for subsequent processes after sending / receiving this frame.

[0243]

[0325] Figure 49 shows an example embodiment 1610 of the PR Control field from Figure 48. The Priority Request subfield indicates the priority of the traffic that the STA that sent this frame requests to be transmitted. The PPDU and ACK Synchronization Request subfield, if set to 1, should cause the STA sending or receiving this frame to align the start of a PPDU and align the start of an Ack / BA in response to each received PPDU.

[0244]

[0326] The PPDU Start Time subfield indicates the option to start transmitting / receiving PPDUs after transmitting / receiving this frame. When set to 0, it means that no specific start time is indicated, and the STA starts transmitting PPDUs over SIFS after completing all control frame exchanges with its destination (e.g., from sending P-RTS to receiving P-CTS in response to P-RTS). When set to 1, it indicates a specific start time, e.g., one PR + CDP frame duration + SIFS + one CTS frame duration + SIFS after receiving this frame for FD STAs. FD STAs transmitting this frame should start counting after transmitting this frame and then add one more SIFS to their previous calculation. The PPDU Duration Alignment subfield, when set to 1, indicates that the PPDU should be padded to end at the same time, as indicated by the L-SIG field in the preamble.

[0245] 7.3.P-CTS (Prioritized CTS)

[0328] Figure 50 illustrates an example embodiment 1630 of a P-CTS frame. An FD STA transmits a P-CTS frame in response to receiving a P-RTS frame. This frame includes Frame Control, Duration / ID, RA, PR Control, and FCS, as shown.

[0246]

[0329] Figure 51 illustrates an example embodiment 1650 of the PR Control field shown in Figure 50. The PR Control field indicates priority request information for subsequent processing after sending / receiving this frame. The Priority Request subfield indicates which priority this P-CTS is a response to, and this priority should be the same as the priority specified in the responded P-RTS frame.

[0247]

[0330] The other fields are the same as those outlined for the P-RTS.

[0248] 7.4.PR+CDP Frame Format

[0332] An example embodiment of a PR+CDP frame 1670 is shown in Figure 52. When an FD AP detects an intra-BSS collision, it can broadcast a new frame (PR+CDP) to declare the AP's request for high-priority data (DATA) transmission (including indicating the priority level), and can also indicate scheduling rules such as PPDU alignment and / or ACK alignment.

[0249]

[0333] A STA that receives a PR+CDP frame and has previously sent a prioritized control frame, such as a P-RTS, to the AP should compare the priority declared by the AP, as carried by the PR+CDP frame, with the priority of the traffic that the STA has requested the AP to transmit. If the priority declared by the AP is higher than the STA's priority, the STA should abort the retransmission of the previous control frame.

[0250]

[0334] Figure 53 shows an example embodiment 1690 of the PR+CDP Control field. The PR+CDP Control field indicates priority request and collision detection probability information and corresponding control information for subsequent processes after transmitting / receiving this frame. The Priority Request subfield indicates the priority that the STA that transmitted this frame requests to be processed first. The Collision Detection Probability subfield indicates the estimated probability of an intra-BSS collision, with possible values ​​of 0 or 1. The PPDU and ACK Synchronization Request subfield, when set to 1, may indicate that the STA transmitting or receiving this frame should align the start of PPDUs and align the start of Acks in response to each received PPDU.

[0251]

[0335] The PPDU Start Time subfield indicates the option to start transmitting / receiving PPDUs after transmitting / receiving this frame. If set as 0, it means that no specific start time is indicated, and the STA starts transmitting PPDUs over SIFS after completing all previous control frame exchanges with its destination (from sending RTS to receiving CTS, which may include additional frame exchanges used to cancel collision detection overestimation).

[0252]

[0336] If set as 1, it indicates a specific start time after, for example, one CTS frame duration + SIFS for FD STAs after receiving this frame. FD STAs transmitting this frame should start counting after transmitting this frame and then add one more SIFS to their previous calculation.

[0253]

[0337] The PPDU Duration Alignment subfield, when set to 1, indicates that the PPDU should be padded to end at the same time as indicated by the L-SIG field in the preamble. The other fields are the same as those defined in the P-RTS frame.

[0254] 8. General Scope of Embodiments

[0339] Embodiments of the present technology may be described herein with reference to flow diagrams of methods and systems according to embodiments of the present technology, and / or procedures, algorithms, steps, operations, formulas, or other computational expressions, which may also be implemented as computer program products. In this regard, each block or step of the flowcharts, and combinations of blocks (and / or steps) of the flowcharts, and any procedures, algorithms, steps, operations, formulas, or computational expressions, may be implemented by various means, such as hardware, firmware, and / or software that includes one or more computer program instructions embodied in computer-readable program code. It will be understood that any such computer program instructions may be executed by one or more computer processors, including, but not limited to, a general-purpose computer or a special-purpose computer, or other programmable processing device to produce a machine, such that the computer program instructions executing on the computer processor(s) or other programmable processing device produce means for implementing the specified function(s).

[0255]

[0340] Thus, the flowchart blocks and procedures, algorithms, steps, operations, formulas, or computational expressions described herein support combinations of means for performing a particular function(s), combinations of steps for performing a particular function(s), and computer program instructions for performing a particular function(s) as embodied in computer-readable program code logic means. It will also be understood that each flowchart block and any procedures, algorithms, steps, operations, formulas, or computational expressions described herein, and combinations thereof, can also be implemented by a dedicated hardware-based computer system that performs the particular function(s) or step(s), or a combination of dedicated hardware and computer-readable program code.

[0256]

[0341] Furthermore, these computer program instructions, embodied in computer-readable program code or the like, may be stored in one or more computer-readable memories or memory devices that can direct a computer processor or other programmable processing device to function in a particular manner, such that the instructions stored in these computer-readable memories or memory devices produce an article of manufacture that includes instruction means that implement the functions specified in the flowchart block(s). The computer program instructions may be executed by the computer processor or other programmable processing device to cause a series of operational steps to be performed on the computer processor or other programmable processing device to generate a computer-implemented process, such that the instructions executing on the computer processor or other programmable processing device provide steps for implementing the function specified in the flowchart block(s), procedure(s), algorithm(s), step(s), operation(s), mathematical formula(s), or computational expression(s).

[0257]

[0342] Furthermore, as used herein, the terms "program" or "program executable" will be understood to mean one or more instructions executable by one or more computer processors to perform one or more functions described herein. The instructions may be embodied in software, firmware, or a combination of software and firmware. The instructions may be stored locally on a non-transitory medium of the device, or remotely, such as on a server, or all or a portion of the instructions may be stored both locally and remotely. Remotely stored instructions may be downloaded (pushed) to the device upon user initiation or automatically based on one or more factors.

[0258]

[0343] Furthermore, as used herein, the terms processor, hardware processor, computer processor, central processing unit (CPU), and computer are used interchangeably to refer to devices capable of executing instructions and communicating with input / output interfaces and / or peripheral devices, and it will be understood that the terms processor, hardware processor, computer processor, CPU, and computer are intended to include single or multiple devices, single-core devices and multi-core devices, and variations thereof.

[0259]

[0344] From the description herein, it will be understood that the present disclosure includes multiple implementations of the technology, including but not limited to the following:

[0260]

[0345] 1. An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a station (STA) for wirelessly communicating with other STAs over a wireless local area network (WLAN) in an IEEE 802.11 protocol configured to support carrier sense multiple access with collision avoidance (CSMA / CA); (b) a processor of the STA; and (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs and performing different roles in a communication protocol, the instructions, when executed by the processor, performing one or more steps of preamble-based collision detection, the one or more steps including: (d)(i) generating, by the STA that is a full-duplex (FD) STA, an orthogonal preamble, the orthogonal preamble including embedded traffic priority information; and processing the preamble, wherein: (d)(i)(A) ​​when the STA detects a colliding preamble having a priority lower than its own priority, (d)(i)(B) when the STA detects a colliding preamble of equal or higher priority than its own priority or no priority, it stops its transmission and starts backoff after detecting that the medium is idle, and (d)(i)(C) if no collision is detected, it continues transmitting the PPDU; and (d)(ii) prioritizing transmissions after processing intra-basic service set (intra-BSS) collision estimation, the steps including: (d)(ii)(A) ​​indicating a priority in each control frame transmitted for collision avoidance; and (d)(ii)(B) allowing high priority traffic to be served before low priority traffic when an intra-BSS collision is estimated by a STA acting as a scheduler.

[0261]

[0346] An apparatus for wireless communication in a network, the apparatus being configured to (a) support carrier sense multiple access with collision avoidance (CSMA / CA) in IEEE 802.and (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs and performing different roles in the communication protocol, (d) the instructions, when executed by the processor, perform one or more steps of preamble-based collision detection, the one or more steps comprising: (i) a FD-based collision detection circuit for detecting a collision between the STA and another STA; generating, by the STA being a STA, orthogonal preambles that are orthogonal in time and / or frequency domain, the orthogonal preambles including embedded traffic priority information, and processing the preambles, (d)(i)(A) ​​retransmitting the preamble and its associated physical layer protocol data unit (PPDU) when the STA detects a colliding preamble with a priority lower than its own priority; (d)(i)(B) ceasing its transmission and initiating backoff after detecting that the medium is idle when the STA detects a colliding preamble with a priority equal to or higher than its own priority or with no priority; and (d)(i)(C) retransmitting the remaining portion of the PPDU when no collision is detected. (d)(ii) prioritizing transmissions after processing an intra-basic service set (intra-BSS) collision estimation, the prioritizing steps including: (d)(ii)(A) ​​indicating a priority in each control frame transmitted for collision avoidance; and (d)(ii)(B) allowing higher priority traffic to be served before lower priority traffic when an intra-BSS collision is estimated by a STA acting as a scheduler; and (d)(iii) initiating a transmission opportunity (TXOP), wherein upon estimating the presence of intra-basic service set (intra-BSS) interference, a frame is broadcast indicating a preferred priority of a request to be served for the TXOP.

[0262]

[0347] A method of wireless communication in a network, comprising: (a) configuring wireless communication circuitry as a station (STA) for wireless communication with other STAs on a wireless local area network (WLAN) in an IEEE 802.11 protocol configured to support Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA), the STA being configured to perform a role in preamble-based collision detection; (b) generating, by the STA being an FD STA, an orthogonal preamble, the orthogonal preamble including embedded traffic priority information; and processing the preamble such that: (b)(i) the STA retransmits the preamble and its associated physical layer protocol data unit (PPDU) when it detects a colliding preamble having a priority lower than its own priority; and (b)(ii) the STA stops its transmission and determines that the medium is idle when it detects a colliding preamble having a priority equal to or higher than its own priority or having no priority. and (b)(iii) continuing to transmit the remainder of the PPDU if no collision is detected; and (c) prioritizing transmissions after processing intra-basic service set (intra-BSS) collision estimations, the prioritizing transmissions comprising: (c)(i) indicating a priority in each control frame transmitted for collision avoidance; and (c)(ii) allowing high priority traffic to be served before low priority traffic when an intra-BSS collision is estimated by a STA acting as a scheduler.

[0263]

[0348] A WLAN device includes the following (a) to (g): (a) A full-duplex (FD) station (STA) is enabled using a new preamble-based collision detection without performing self-interference (SI) estimation, providing a new collision resolution estimation and scheduling for prioritized communications; (b) An orthogonal preamble is used to detect collisions faster without performing self-interference channel estimation; (c) Priority information is embedded in the preamble; (d) The priority level can be predetermined and agreed upon by all FD STAs, for example, embedded in the FD preamble field following the legacy preamble field specified in IEEE 802.11; (e) If a STA detects a colliding preamble with a lower priority than its own, it retransmits the preamble and its PPDU; otherwise, it stops transmission and starts backoff after detecting that the channel is idle; (f) If a FD STA detects a collision without detecting the priority of the colliding preamble, it should stop transmission and start backoff after detecting that the channel is idle; (g) If a collision is not detected, the STA continues transmitting the remaining part of the PPDU.

[0264]

[0349] An apparatus or method of any preceding implementation, wherein the preamble-based collision detection is performed without having to perform self-interference cancellation (SIC) channel estimation.

[0265]

[0350] An apparatus or method of any preceding implementation, wherein priority information is embedded in a preamble as predetermined and / or agreed upon by stations on the wireless network.

[0266]

[0351] An apparatus or method of any preceding implementation, wherein priority information is embedded in a preamble following a legacy preamble field as specified in 802.11.

[0267]

[0352] An apparatus or method of any preceding implementation, wherein the orthogonal preambles are orthogonal in the time domain, or in the frequency domain, or in both the time domain and the frequency domain.

[0268]

[0353] An apparatus or method of any preceding implementation, wherein the orthogonal preamble in the time domain carries an orthogonal priority signal that is orthogonal to other priority signals carried by preambles of other STAs.

[0269]

[0354] An apparatus or method of any preceding implementation, wherein the orthogonal priority signals are pre-configured and center frequency synchronization between transmitters is required.

[0270]

[0355] An apparatus or method of any preceding implementation, wherein the orthogonal preambles in the frequency domain include priority information that can be embedded in different subcarriers that are spaced at least 40 ppm apart.

[0271]

[0356] An apparatus or method of any of the preceding implementations, wherein the STA zeros out tones in its own FD preamble to discover other STAs with different priorities.

[0272]

[0357] The apparatus or method of any preceding implementation, wherein the FD STA can initiate a transmit opportunity (TXOP) including a request to send (RTS), clear to send (CTS), and message exchange.

[0273]

[0358] An apparatus or method of any preceding implementation, wherein upon estimating the presence of intra-basic service set (intra-BSS) interference, a frame is broadcast indicating a preferred priority of a request to be processed for the TXOP.

[0274]

[0359] An apparatus or method of any of the above implementations, wherein after receiving a frame indicating the requested traffic priority, each FD STA on the network performs the following actions depending on which traffic priority is being processed: (i) when processing traffic of a priority lower than the requested priority, each FD STA stops any transmissions and retransmissions, and (ii) when processing traffic of a priority higher than or equal to the requested priority, each FD STA continues their respective transmitter and receiver processing.

[0275]

[0360] An apparatus or method of any of the preceding implementations, wherein the STA is an FD access point (AP), and the FD AP triggers non-AP FD STAs on the network to begin transmitting low-prioritized traffic, allowing these non-AP FD STAs with low-prioritized traffic to re-access the channel without having to be triggered if the channel has been idle for at least a PIFS duration after receiving a broadcast frame indicating that high-prioritized traffic is given priority.

[0276]

[0361] An apparatus or method of any of the above implementations, wherein after processing the requested priority traffic, the FD STA that broadcast the frame containing the requested priority information sends another frame to estimated colliding FD STAs on the network that have lower priority traffic indicating that they can begin sending and receiving lower priority traffic.

[0277]

[0362] An apparatus or method of any preceding implementation, wherein the FD STA initiates a transmit opportunity (TXOP) by transmitting a DATA PPDU.

[0278]

[0363] An apparatus or method of any of the above implementations, which estimates an intra-basic service set (intra-BSS) collision using simultaneously transmitted and received preambles and makes a process decision based on priority resolution as follows: (a) when it is estimated that there is an intra-BSS collision with a lower priority than itself, the PPDU is retransmitted; (b) when it is estimated that there is an intra-BSS collision with a higher priority than itself, the transmission of the PPDU is stopped unless a control frame is received from a reserved RU or a non-reserved RU; and (c) when a preamble that does not include a DATA PPDU portion is received, a control frame is transmitted through a reserved RU to indicate that there is an over-estimated intra-BSS collision.

[0279]

[0364] In response to the overestimated intra-BSS collision, the STA in the network that sent the preamble receives the control frame through a reserved RU and retransmits or triggers the retransmission of a previously terminated low-priority PPDU that was overestimated as an intra-BSS collision signal.

[0280]

[0365] An apparatus or method of any of the above implementations, wherein after receiving a frame indicating the requested traffic priority, each FD STA on the network performs the following actions depending on which traffic priority is being processed: (i) when processing traffic of a priority lower than the requested priority, each FD STA stops any transmissions and retransmissions, and (ii) when processing traffic of a priority higher than or equal to the requested priority, each FD STA continues their respective transmitter and receiver processing.

[0281]

[0366] An apparatus or method of any of the above implementations, where after processing an intra-BSS collision estimation, prioritized transmission is ensured: (a) the FD STA should indicate priority in a control frame used for collision avoidance; and (b) the FD scheduler STA should be able to process high priority traffic before low priority traffic when an intra-BSS collision is estimated.

[0282]

[0367] An apparatus or method of any preceding implementation, wherein the FD STA uses orthogonal preambles in the time domain and / or the frequency domain.

[0283]

[0368] An apparatus or method of any of the preceding implementations, wherein for time-domain orthogonal preambles: (i) each STA transmits an FD preamble of a PPDU carrying a priority signal that is orthogonal to other priority signals carried by the FD preambles of other STAs, the orthogonal priority signals being pre-configured; and (ii) the application requires center frequency synchronization between transmitters.

[0284]

[0369] For orthogonal preambles in the frequency domain: (i) priority information can be embedded in different subcarriers that are spaced at least 40 ppm apart in the frequency domain of the FD preamble; (ii) at baseband after analog cancellation and before digital cancellation (note that digital cancellation requires SI channel estimation), a STA zeros out the tones of its own FD preamble to discover other STAs with different priorities; (iii) since this application is CFO tolerant, it may not require center frequency synchronization between transmitters.

[0285]

[0370] An FD STA can initiate a TXOP including an RTS / CTS exchange: (a) an FD STA that estimates the presence of intra-BSS interference can broadcast a frame indicating the preferred priority it requests to be processed first; (b) after receiving a frame indicating the requested traffic priority, FD STAs perform differently depending on the traffic priority they are processing, as follows: (i) FD STAs should stop any transmission / retransmission to accommodate traffic of lower priority than the requested priority; (ii) FD STAs should continue their TX / RX process to accommodate traffic of higher / same priority than the requested priority; (c) an FD AP can trigger non-AP FD devices to start transmitting low-prioritized traffic; these non-AP FD devices with low-prioritized traffic can re-access the channel without being triggered if the channel is idle for at least a PIFS duration after receiving a broadcast frame indicating that high-prioritized traffic is prioritized; (d) after finishing processing the requested priority traffic, an FD STA that broadcast a frame including the requested priority information can re-access the estimated collision FD device with low-priority traffic. An apparatus or method of any of the preceding implementations may send another frame to the STA to begin the process of transmitting and receiving low priority traffic.

[0286]

[0371] An apparatus or method of any of the above implementations, wherein an FD STA that stops (re)transmission after receiving a broadcast frame containing a requested priority higher than its own priority can access the medium if it does not receive or detect any frames from a STA dealing with traffic of the requested priority after a certain time, e.g., 1 PIFS, after stopping (re)transmission.

[0287]

[0372] An apparatus or method of any of the preceding implementations, wherein an FD STA that overestimates an intra-BSS collision should recognize the overestimate after receiving a response frame from the estimated collision destination.

[0288]

[0373] An apparatus or method of any of the above implementations, wherein an FD STA that discovers that it has overestimated an intra-BSS collision should send a response frame to the overestimated collision source that sent a frame, e.g., an RTS including a priority, but has not received a response frame.

[0289]

[0374] An apparatus or method of any of the above implementations, wherein FD STAs with different traffic priorities receive responses from their destinations and enable their transmission, and the FD STAs can begin transmitting one or more PPDUs to their destinations simultaneously with aligning the start and end points of the PPDUs or aligning the lengths of the PPDUs.

[0290]

[0375] An apparatus or method of any of the above implementations, wherein alignment of the PPDU start time can be achieved based on (a) a predetermined time from when the collision-detecting STA transmits the first frame, e.g., P-RTS, until it receives a response frame, e.g., P-CTS, and additional SIFS; and (b) alignment information, e.g., PPDU start time, can be defined in a broadcasted frame indicating the request priority.

[0291]

[0376] The alignment of the PPDU length can be achieved as follows: (a) indicated in the first frame to start a new TXOP, e.g., P-RTS; (b) indicated in a broadcasted frame indicating the request priority; and (c) indicated in a management frame exchangeable between the AP and the STA, in an apparatus or method of any of the above implementations.

[0292]

[0377] An apparatus or method of any of the preceding implementations, wherein a destination FD STA receiving a PPDU as described in the preceding paragraph should respond with an Ack / BA simultaneously with the Ack / BA alignment, and the transmitted Ack / BA should not overlap with any simultaneous TX / RX of the PPDU at the Ack / BA destination.

[0293]

[0378] The Ack / BA alignment can be achieved as follows: (a) sending a BA request with each PPDU, and the FD STA responds with only a BA when it receives the BA request; (b) configuring the first frame to start a new TXOP, e.g., in a P-RTS, or in a broadcasted frame indicating the request priority, or in a management frame exchangeable between the AP and the STA, as described in the preceding paragraph, in an apparatus or method of any of the above implementations.

[0294]

[0379] An apparatus or method of any of the preceding implementations, wherein the FD STA can initiate a TXOP by sending a DATA PPDU.

[0295]

[0380] The simultaneously transmitted and received preambles are used to estimate an intra-BSS collision, and the following process is decided based on priority resolution: (a) an FD device that estimates the existence of an intra-BSS collision with a lower priority than itself should retransmit the PPDU and can reserve a part of the RU for this device to exchange control messages between the AP and other STAs, rather than for DATA PPDUs; (b) an FD device that estimates the existence of an intra-BSS collision with a higher priority than itself should stop transmitting the remaining part of the PPDU unless it receives a control frame (e.g., a trigger from the destination) from the reserved RU or a non-reserved RU; if this STA does not hear any other frame exchanges between other STAs, it can access the channel again after EDCA backoff when it is CCA idle; and (c) a DATA PPDU can be reserved for this device. An apparatus or method of any of the above implementations, wherein an FD device that receives only the preamble without the remainder of the PPDU can transmit a control frame using a reserved RU (which can be a predetermined RU) to indicate that an over-estimated intra-BSS collision exists, and when the preamble source STA receives this control frame through the reserved RU, it can retransmit (through the reserved RU) or trigger retransmission of a previously terminated low-priority PPDU that was over-estimated as an intra-BSS collision signal.

[0296]

[0381] An apparatus or method of any of the preceding implementations, wherein if the FD STA can receive PPDUs of different flows at the same time, it should respond with an Ack / BA at the same time as the Ack / BA alignment.

[0297]

[0382] The Ack / BA alignment can be achieved as follows: (a) sending a BA request with each PPDU, and the FD STA responds with only a BA when it receives the BA request; (b) configuring what is described in the preceding paragraph in the first frame to start a new TXOP, or in a control frame indicating the request priority, or in a management frame exchangeable between the AP and the STA; an apparatus or method of any of the above implementations.

[0298]

[0383] The alignment of the PPDU end point can be achieved as follows: (a) indicated in the first frame to start a new TXOP, (b) indicated in a control frame indicating the request priority and exchanged in the reserved RU, and (c) indicated in a management frame exchangeable between the AP and the STA, in an apparatus or method of any of the above implementations.

[0299]

[0384] As used herein, the term "implementation" is intended to include, but is not limited to, any embodiment, example, or other form of implementing the techniques described herein.

[0300]

[0385] As used herein, the singular words "a," "an," and "the" may include plural references unless the context clearly dictates otherwise. Reference to an item in the singular does not mean "one and only one" unless expressly stated otherwise, but rather means "one or more."

[0301]

[0386] Phrasal constructions within this disclosure such as "A, B and / or C" describe when either A, B, or C can be present, or any combination of items A, B, and C. Phrasal constructions such as "at least one of" followed by a listed group of elements indicate that at least one of the group elements is present, and, where applicable, includes any possible combination of the listed elements.

[0302]

[0387] Reference herein to "one embodiment," "at least one embodiment," or similar embodiment terminology indicates that a particular feature, structure, or characteristic described in connection with the described embodiment is included in at least one embodiment of the present disclosure. Thus, these various embodiment phrases do not necessarily all refer to the same embodiment or to a specific embodiment that is different from all other embodiments described. The embodiment phrase should be interpreted to mean that the particular feature, structure, or characteristic of a given embodiment can be combined in any suitable manner in one or more embodiments of the disclosed devices, systems, or methods.

[0303]

[0388] As used herein, the term "set" means a collection of one or more objects. Thus, for example, a set of objects can include a single object or multiple objects.

[0304]

[0389] Relative terms such as first and second, top and bottom, etc. may be used only to distinguish one entity or action from another and do not necessarily require or imply that any actual relationship or order exists between such entities or actions.

[0305]

[0390] The terms "comprises," "comprising," "has," "having," "includes," "including," "contains," "containing," or any other variations of these terms, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises, includes, contains, or has a list of elements may include other elements not expressly listed or inherent to such process, method, article, or apparatus, rather than including only those elements. An element introduced by "comprises...a," "has...a," "includes...a," or "contains...a" does not, in the absence of further constraints, exclude the presence of additional identical elements within the process, method, article, or apparatus that comprises, includes, contains, or has that element.

[0306]

[0391] As used herein, the terms “approximately,” “approximate,” “substantially,” “essentially,” and “about,” or any other versions of these terms, are intended to describe and explain slight variations. When used in connection with events or circumstances, these terms can mean that the events or circumstances will definitely occur and that the occurrence of these events or circumstances is highly probable. When used in connection with a numerical value, these terms can mean a variation range of ±10% or less, such as ±5% or less, ±4% or less, ±3% or less, ±2% or less, ±1% or less, ±0.5% or less, ±0.1% or less, or ±0.05% or less of the numerical value. For example, being “substantially” aligned can mean an angular variation range of ±10% or less, such as ±5° or less, ±4° or less, ±3° or less, ±2° or less, ±1° or less, ±0.5° or less, ±0.1° or less, or ±0.05° or less.

[0307]

[0392] In addition, amounts, ratios, and other numerical values ​​may be presented in range format herein. Such range formats are used as a shorthand for convenience and should be understood to include numerical values ​​explicitly specified as the limits of the range, but should also be understood to include all individual numerical values ​​or subranges within the range, as if each such numerical value and subrange were expressly set forth. For example, a ratio within the range of about 1 to about 200 should be understood to include the explicitly recited limits of about 1 and about 200, but also to include individual ratios such as about 2, about 3, and about 4, as well as subranges such as about 10 to about 50 and about 20 to about 100.

[0308]

[0393] The term "coupled," as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. A device or structure that is "configured" in a particular way is configured in at least that way, but may also be configured in unrecited ways.

[0309]

[0394] Benefits, advantages, solutions to problems, and any element(s) that may result in or make more apparent any benefit, advantage, or solution should not be construed as a critical, necessary, or essential feature or element of the technology described herein or any or all of the claims.

[0310]

[0395] Furthermore, in the foregoing disclosure, various features may be grouped together in various embodiments for brevity of the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Inventive subject matter may comprise less than all features of a single disclosed embodiment.

[0311]

[0396] The Abstract of the Disclosure is intended to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

[0312]

[0397] It is understood that some jurisdictions have a practice of requiring the deletion of one or more portions of the disclosure after filing. Therefore, the reader should refer to the application as of its filing date for the original content of the disclosure. The deletion of any of the disclosure content should not be construed as an abandonment, forfeiture, or public disclosure of any subject matter of the application as originally filed.

[0313]

[0398] The following claims are hereby incorporated into this disclosure, with each claim standing on its own as separately claimed subject matter.

[0314]

[0399] Although the description herein contains many details, these should not be construed as limiting the scope of the disclosure, but merely as exemplifying some of the presently preferred embodiments, and therefore, the scope of the disclosure will be understood to fully encompass other embodiments that may become apparent to those skilled in the art.

[0315]

[0400] All structural and functional equivalents of elements of the embodiments of the present disclosure known to those skilled in the art are expressly incorporated herein by reference and are intended to be within the scope of the claims. Furthermore, no elements, components, or method steps of the present disclosure are intended to be publicly disclosed, regardless of whether they are explicitly recited in the claims. No claim element herein should be construed as a "means-plus-function" element unless the element is expressly recited using the phrase "means for." Also, no claim element herein should be construed as a "step-plus-function" element unless the element is expressly recited using the phrase "step for." [Explanation of symbols]

[0316] 10 Example of Implementation 12 Tx Digital BB 14 DAC and UC 15 circuits 16 TX antenna 18 Rx Digital BB 19 Apply digital SIC 20 ADC and DC 22 RX antenna 23 Subtract / SIC correction applied 24 Digital SIC 26a~26n variable delay 28a~28n variable attenuator 30 Radio Frequency Front End (RFFE) 50 Example of Implementation 52 circuits 54 External I / O Connections / Bus 56 Internal Bus 58 CPUs / Processors 60 memory 62 Modem 64,68 RF Module 66a, 66b, 66c, …, 66n, 69 Antenna 90 Example of Implementation 92 STA1 94 STA2 96 STA_N 98 MLD Management Entity 100 CPU 102 memory 104 modem 106 RF circuit 108 Bus 110a, 110b, 110c, ..., 110n antennas 112 CPU 114 memory 150 Example of Implementation 152 FD AP 154 FD STA1 156 FD STA2 160 Example of Implementation 162 FD AP 164 FD STA 170 Example of Implementation 172 FD AP 174 FD STA1 176 FD STA2 180,200 Examples of self-interfering paths 182 STA 184 Transmission Chain 186 Antenna 188 receive chain 190 Antenna 192 External reflection 202 Combine 204 Join 210 Single Antenna 212 External reflection 220 Example of Implementation 222 Collision with FD preamble signal of STA with priority 2 224 STA with priority 1 detects its own FD preamble 230 Example of Implementation 232 Preamble 234 FD Preamble 236a priority=0 236b priority=1 236c priority=2 236d priority=0 240 Example of Implementation 242 Preamble 243 FD Preamble 244a priority=0 244b priority=1 246a priority=0 246b priority=1 250 Example of Implementation 252 Preamble 252a priority=0 252b priority=0 253 Legacy Preamble 254 FD Preamble 254a priority=0 254b priority=0 256a priority=0 256b priority=0 258 FFT windows 260 Example of Implementation 270 Topology 272 FD AP 274 FD STA1 276 Half-duplex STA2 280 Example of Implementation 282 Collision FD preamble priority detected? 284 Is the detected priority lower than the STA's priority? 286 retransmission 288 Continue transmitting the rest of the PPDU 290 Collision FD preamble detected? 292 Stop sending and start backoff 300 Example of embodiment 302 FD AP 304 FD STA1 306 FD STA2 310 Example of Implementation 312 FD AP 314 FD STA1 316 FD STA2 318 P-RTS to STA2 P-RTS to 319 AP 320 Priority Request + Collision Detection Probability (PR+CDP) 321 STA1 cancels retransmission of RTS to AP 322 P-RTS to STA2 323 CCA Busy P-CTS to 324 AP 326 PPDU to STA2 ACK to 328 AP ACK to 330 AP ACK to 332 AP 334 Trigger to STA1 336 CCA Busy PPDU to 338 AP 340 ACK to STA1 342 ACK to STA1 410 Example of Implementation 412 Trigger frame to STA1 414 CCA Busy PPDU to 418 AP 420 ACK to STA1 422 ACK to STA1 424 P-RTS to STA2 426 CCA Busy P-CTS to 428 AP 430 PPDU to STA2 ACK to 432 AP ACK to 434 AP 510 Example of Implementation 512 CCA Busy P-RTS to 514 AP 516 CCA Busy 518 P-CTS to STA1 PPDU to 520 AP 522 ACK to STA1 524 ACK to STA1 526 P-RTS to STA2 528 CCA Busy P-CTS to 530 AP 532 PPDU to STA2 ACK to 534 AP ACK to 536 AP 610 Example of Implementation 612 P-RTS to STA2 614 CCA Busy P-CTS to 616 AP 618 PPDU to STA2 ACK to 620 AP ACK to 622 AP 624 Trigger to STA1 625 CCA Busy PPDU to 626 AP 628 ACK to STA1 630 ACK to STA1 710 Example of Implementation 712 P-CTS to STA1 714 CCA Busy PPDU to 716 AP 718 ACK to STA1 720 ACK to STA1 722 P-RTS to STA2 724 CCA Busy P-CTS to 726 AP 728 PPDU to STA2 ACK to 730 AP ACK to 732 AP 750 Topology Example 752 Full Duplex AP 754 Full duplex STA1 756 Full duplex STA2 790 Topography Examples 792 FD AP2 794,796 OBSS interference 798 FD STA2 800 FD STA1 802 FD AP1 804 High Priority Traffic 810 Topography Examples 812 FD AP1 814 High Priority Traffic 816 Low Priority Traffic 850a Case 1 850b Case 2 850c Case 3 850d Case 4 852 FD STA1 854 FD AP 856 FD STA2 858 FD STA3 910 Example of Implementation 912 PR+CDP P-CTS to 914 AP 916 P-CTS to STA1 P-RTS to 918 AP 920 CCA Busy 922 PPDU Alignment 924 PPDU to STA2 PPDU to 925 AP 926 ACK Alignment 928 ACK to STA1 ACK to 929 AP 930 PPDU Alignment 932 PPDU to STA2 PPDU to 933 AP 934 ACK Alignment 936 ACK to STA1 ACK to 937 AP 938 PPDU to STA2 940 CCA Busy ACK to 942 AP 950 Example of embodiment 952 (including priority) P-RTS sent? 954 Was a P-RTS received at the same time? 956 Does P-RTS have low priority for intra-BSS collision estimation? 958 PR+CDP broadcast? 960 Are intra-BSS collisions overestimated? 962 Respond with P-CTS to low priority traffic sources 964 (including priority) P-RTS retransmission 966 Completed TX / RX sequence for high priority traffic 968 Should frames be sent to low priority traffic sources? 970 Completed TX / RX sequence for low priority traffic 972 Simultaneous handling of high-priority and low-priority traffic 974 P-CTS response 976 Was a P-CTS received before the P-CTS timeout? Send 978 PPDU Receive 980 ACK / BA 982 Has the TXOP expired and do I need to send any more PPDUs? 984 P-CTS Timeout Resend 986 P-RTS 988 (including priority) P-RTS received? Respond with 990 P-CTS 992 Receive one or more PPDUs and BARs and respond with ACK / BA 1012 (including priority) P-RTS sent? 1014 Simultaneous P-RTSs are received and an intra-BSS collision is assumed to exist? 1016 PR+CDP frame received? 1018 Stop retransmission of P-RTS (including priority) 1020 Have you received a P-RTS frame indicating higher / same priority? 1022 Have you detected high priority P-RTS / P-CTS / DATA being sent within a short interval? 1024 CCA can be used to send a frame to the previous destination requesting processing. 1026 Has a frame been received to trigger / start PPDU transmission? Completed 1028 traffic TX / RX sequences 1030 Response Frame Timeout 1032 Stop sending or retransmitting 1034 Was a P-CTS received before the P-CTS timeout? Send 1036 PPDUs 1038 ACK / BA received 1040 Has the TXOP expired and do I need to send any more PPDUs? 1042 P-CTS Timeout 1044 (including priority) P-RTS retransmission 1046 (including priority) Have you received P-RTS? 1048 P-CTS response 1050 Receive one or more PPDUs and BARs and respond with ACK / BA 1112 Preamble (HP) 1114 Preamble (LP) 1116 Preamble 1118 Preamble (HP) 1120 CCA Busy 1122 PPDU to STA2 1124 ACK to AP 1126 ACK to AP 1128 Trigger to STA1 1130 CCA Busy 1132 Preamble (LP) PPDU to 1134 AP 1136 ACK to STA1 1138 ACK to STA1 1210 Example of embodiment 1212 Preamble (HP) 1214 Preamble (LP) 1216 Preamble (HP) 1218 Reserved RU 1220 PPDU to STA2 1222 Trigger 1224 Preamble (LP) 1225 PPDU Alignment 1226 PPDU to AP 1228 ACK Alignment 1230 ACK to STA1 ACK to 1231 AP 1232 PPDU Alignment 1234 PPDU to STA2 PPDU to 1235 AP 1236 ACK Alignment 1238 ACK to STA1 ACK to 1239 AP 1240 PPDU to STA2 1242 CCA Busy ACK to 1246 AP 1310 Example of Implementation 1312 Preamble (LP) 1314 Preamble (HP) 1316 Preamble 1318 Preamble (HP) 1320 CCA Busy PPDU to 1322 AP 1324 ACK to STA1 1326 Preamble (LP) 1328 CCA Busy 1330 PPDU to STA2 ACK to 1332 AP ACK to 1334 AP 1410 Example of embodiment 1412 Preamble (LP) 1414 Preamble (HP) 1418 Preamble (HP) 1420 CCA Idol 1422 Control Frames 1424 Preamble (LP) PPDU to 1426 AP 1428 PPDU to STA2 1430 ACK to STA1 ACK to 1431 AP 1432 Preamble (LP) 1434 Preamble (HP) 1436 PPDU to STA2 / PPDU to AP 1438 ACK to STA1 ACK to 1439 AP 1470 Example of Implementation 1472 Are intra-BSS collisions assumed to have lower priority than the AP itself? 1474 Retransmit PPDU containing reservation of some RUs for other STAs 1476 Has a control frame been received from the destination STA via a reserved RU indicating an overestimation of intra-BSS collisions? 1478 may terminate the current PPDU transmission sequence and send a trigger to other STAs that are presumed to be colliding STAs with lower priority 1480 Send ACK / BA in response to received PPDU 1482 Transmit a control (trigger) frame in the reserved RU to trigger the estimated colliding STA to transmit a TB-PPDU. Maintain PPDU end and / or start alignment and BA / ACK alignment under 1484 schedule (if any) 1486 Stop sending the rest of the PPDU 1488 Has a control frame been received from the destination STA via a reserved RU indicating an overestimation of intra-BSS collisions? 1490 DL PPDUs can be retransmitted, and all the while UL PPDUs can be received. 1492 Send ACK / BA in response to received PPDU 1494 may terminate the current PPDU transmission sequence and send a trigger to other STAs that are presumed to be colliding STAs with lower priority Example embodiment 1510 1512 Did the STA receive a preamble that did not contain the remainder of the DATA PPDU? 1514 Intra-BSS collision assumed to have lower priority than the STA itself? 1516 Retransmit PPDUs that reserve some RUs for other STAs 1518 Maintain PPDU end and / or start alignment and BA / ACK alignment under schedule (if any) 1520 Send a control frame using reserved RUs to indicate an overestimated intra-BSS collision 1522 Send ACK / BA in response to received PPDU 1524 Stop sending the rest of the PPDU 1526 Has a control frame triggering a UL PPDU been received from the destination STA (AP) via a reserved or unreserved RU? 1528 UL PPDU retransmission 1530 Retransmit PPDU after EDCA backoff when CCA idle if not listening to frame exchange between other STAs 1590 P-RTS Frame Example 1610 Example of embodiment 1630 Example of embodiment 1650 Example of embodiment 1670 Example of implementation 1690 Example of implementation

Claims

1. 1. An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a station (STA) for wirelessly communicating with other STAs over a wireless local area network (WLAN) in an IEEE 802.11 protocol configured to support carrier sense multiple access with collision avoidance (CSMA / CA); (b) a processor of the STA; and (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs and performing different roles in a communication protocol; Equipped with (d) the instructions, when executed by the processor, perform one or more steps of preamble-based collision detection, the one or more steps comprising: (i) generating an orthogonal preamble by the STA, the orthogonal preamble including embedded traffic priority information, and processing the preamble, the orthogonal preamble being a full-duplex (FD) STA; (A) when the STA detects a colliding preamble having a priority lower than its own priority, retransmitting the preamble and its associated physical layer protocol data unit (PPDU); (B) when the STA detects a colliding preamble with a priority equal to or higher than its own priority or with no priority, it stops its transmission and starts backoff after detecting that the medium is idle; (C) if no collision is detected, continuing to transmit the PPDU; and and (ii) prioritizing transmissions after processing intra-basic service set (intra-BSS) collision estimates, (A) indicating a priority in each control frame transmitted for collision avoidance; (B) allowing high priority traffic to be served before low priority traffic when an intra-BSS collision is estimated by the STA or the other STA acting as a scheduler; and Including, the orthogonal preambles are orthogonal in the time domain, or in the frequency domain, or in both the time domain and the frequency domain; the orthogonal preamble in the frequency domain includes priority information that can be embedded in different subcarriers spaced at least 40 ppm apart; An apparatus characterized in that

2. 10. The apparatus of claim 1, wherein the preamble-based collision detection is performed without having to perform self-interference cancellation (SIC) channel estimation.

3. 2. The apparatus of claim 1, wherein priority information is embedded in a preamble as predetermined and / or agreed upon by stations on the wireless local area network.

4. 2. The device of claim 1, wherein priority information is embedded in a preamble following a legacy preamble field defined in 802.

11.

5. 2. The apparatus of claim 1, wherein the orthogonal preamble in the time domain carries an orthogonal priority signal that is orthogonal to other priority signals carried by preambles of other STAs.

6. 6. The apparatus of claim 5, wherein the orthogonal priority signals are preconfigured such that center frequency synchronization between transmitters is required.

7. The apparatus of claim 1 , wherein the STA zeros out tones of its own FD preamble to discover other STAs with different priorities.

8. 10. The apparatus of claim 1, wherein the FD STA can initiate a transmit opportunity (TXOP) including a request to send (RTS), clear to send (CTS), and message exchange.

9. 10. The apparatus of claim 8, wherein upon estimating the presence of intra-basic service set (intra-BSS) interference, a frame is broadcast indicating a preferred priority of a request to be processed for the TXOP.

10. 10. The apparatus of claim 1, wherein after receiving a frame indicating a requested traffic priority, each FD STA on the network performs the following actions depending on which traffic priority is being processed: (i) when processing traffic of a priority lower than the requested priority, each FD STA stops any transmissions and retransmissions, and (ii) when processing traffic of a priority higher than or equal to the requested priority, each FD STA continues their respective transmitter and receiver operations.

11. 10. The apparatus of claim 1, wherein the STA is an FD access point (AP), and the FD AP triggers non-AP FD STAs on the network to begin transmitting low-prioritized traffic so that those non-AP FD STAs with low-prioritized traffic can re-access the channel without needing to be triggered if the channel has been idle for at least a PIFS duration after receiving a broadcast frame indicating that high-prioritized traffic is given priority.

12. 10. The apparatus of claim 1, wherein after processing requested priority traffic, the FD STA that broadcast the frame containing the requested priority information transmits another frame to estimated colliding FD STAs on the network that have lower priority traffic indicating that they may begin transmitting and receiving lower priority traffic.

13. The apparatus of claim 1 , wherein the FD STA initiates a transmission opportunity (TXOP) by transmitting a DATA PPDU.

14. 14. The apparatus of claim 13, wherein the apparatus estimates an intra-basic service set (Intra-BSS) collision using simultaneously transmitted and received preambles, and makes a process decision based on priority resolution as follows: (a) when an Intra-BSS collision with a lower priority than itself is estimated, the PPDU is retransmitted; (b) when an Intra-BSS collision with a higher priority than itself is estimated, the transmission of the PPDU is stopped unless a control frame is received from a reserved RU or a non-reserved RU; and (c) when a preamble not including a DATA PPDU portion is received, a control frame is transmitted through a reserved RU to indicate the existence of an overestimated Intra-BSS collision.

15. 15. The apparatus of claim 14, wherein, in response to the over-estimated intra-BSS collision, the STA in the network that sent the preamble receives the control frame through a reserved RU and retransmits or triggers retransmission of a previously terminated low-priority PPDU that was over-estimated as an intra-BSS collision signal.

16. 1. An apparatus for wireless communication in a network, the apparatus comprising: (a) wireless communication circuitry as a station (STA) for wirelessly communicating with other STAs over a wireless local area network (WLAN) in an IEEE 802.11 protocol configured to support carrier sense multiple access with collision avoidance (CSMA / CA); (b) a processor of the STA; and (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs and performing different roles in a communication protocol; Equipped with (d) the instructions, when executed by the processor, perform one or more steps of preamble-based collision detection, the one or more steps comprising: (i) generating, by the STA that is an FD STA, orthogonal preambles that are orthogonal in the time domain and / or the frequency domain, the orthogonal preambles including embedded traffic priority information, and processing the preambles; (A) when the STA detects a colliding preamble having a priority lower than its own priority, retransmitting the preamble and its associated physical layer protocol data unit (PPDU); (B) when the STA detects a colliding preamble with a priority equal to or higher than its own priority or with no priority, it stops its transmission and starts backoff after detecting that the medium is idle; (C) if no collision is detected, continuing to transmit the remainder of the PPDU; and and (ii) prioritizing transmissions after processing intra-basic service set (intra-BSS) collision estimates, (A) indicating a priority in each control frame transmitted for collision avoidance; (B) allowing high priority traffic to be served before low priority traffic when an intra-BSS collision is estimated by the STA or the other STA acting as a scheduler; and (iii) initiating a transmission opportunity (TXOP), wherein upon estimating the presence of intra-basic service set (intra-BSS) interference, a frame is broadcast indicating a preferred priority of a request to be processed for said TXOP; Including, the orthogonal preambles are orthogonal in the time domain, or in the frequency domain, or in both the time domain and the frequency domain; the orthogonal preamble in the frequency domain includes priority information that can be embedded in different subcarriers spaced at least 40 ppm apart; An apparatus characterized in that

17. 17. The apparatus of claim 16, wherein after receiving a frame indicating a requested traffic priority, each FD STA on the network performs the following actions depending on which traffic priority is being processed: (i) when processing traffic of a priority lower than the requested priority, each FD STA stops any transmissions and retransmissions, and (ii) when processing traffic of a priority higher than or equal to the requested priority, each FD STA continues their respective transmitter and receiver operations.

18. 1. A method of wireless communication in a network, comprising: (a) configuring wireless communication circuitry as a station (STA) for wireless communication with other STAs over a wireless local area network (WLAN) in an IEEE 802.11 protocol configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA), the STA being configured to perform a role in preamble-based collision detection; (b) generating, by the STA that is an FD STA, an orthogonal preamble, the orthogonal preamble including embedded traffic priority information, and processing the preamble; (i) when the STA detects a colliding preamble having a priority lower than its own priority, retransmitting the preamble and its associated physical layer protocol data unit (PPDU); (ii) when the STA detects a colliding preamble with a priority equal to or higher than its own priority or with no priority, it stops its transmission and starts backing off after detecting that the medium is idle; (iii) if no collision is detected, continuing to transmit the remainder of the PPDU; and and (c) prioritizing transmissions after processing intra-basic service set (intra-BSS) collision estimates, comprising: (i) indicating a priority in each control frame transmitted for collision avoidance purposes; (ii) allowing high priority traffic to be served before low priority traffic when an intra-BSS collision is estimated by the STA or the other STA acting as a scheduler; and Including, the orthogonal preambles are orthogonal in the time domain, or in the frequency domain, or in both the time domain and the frequency domain; the orthogonal preamble in the frequency domain includes priority information that can be embedded in different subcarriers spaced at least 40 ppm apart; A method characterized by:

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