Collision detection and collision resolution for prioritized full-duplex communication

Abstract

A preamble-based collision detection mechanism for wireless local area networks (WLANs) with one or more full-duplex (FD) stations. Additionally, a new collision resolution estimation and scheduling mechanism is described for prioritized communications. These techniques can allow for faster collision detection and resolution without the need for self-interference (SI) estimation. These techniques include the use of orthogonal preambles in the time and / or frequency domain, with FD stations embedding priority information in the orthogonal preambles.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Patent Application Serial No. 17 / 819,285, filed August 11, 2022, which is incorporated herein by reference in its entirety. This application also claims priority and benefit to U.S. Provisional Patent Application Serial No. 63 / 261,062, filed September 9, 2021, which is incorporated herein by reference in its entirety.

[0003] Statement on Federally Funded Research and Development

[0004] not applicable

[0005] Declaration of copyrighted materials

[0006] Some material in this patent document is protected by copyright laws in the United States and other countries. The copyright holder does not object to any reproduction of this patent document or patent disclosure as if it were found in publicly available U.S. Patent and Trademark Office documents or archives, but retains all other copyrights. The copyright holder therefore does not waive any right to keep this patent document confidential, including but not limited to its rights under 37C.FR §1.14. Technical Field

[0007] The technology disclosed herein generally relates to wireless local area networks (WLANs), and more specifically to full-duplex WLANs that address the problem of self-interference. Background Technology

[0008] The use of full-duplex (FD) technology in wireless local area networks (WLANs) is becoming increasingly important because of its ability to improve spectrum efficiency.

[0009] However, when using FD, a problem arises where FD devices receive self-interference (SI) from the same device through transceiver coupling and multipath reflection.

[0010] Therefore, there is a need for FD techniques to solve the SI problem. This disclosure meets this need and provides additional benefits. Summary of the Invention

[0011] A novel preamble-based collision detection apparatus and method are disclosed, which can be performed without self-interference (SI) estimation. A novel collision resolution estimation and scheduling mechanism is also disclosed for use in priority-based traffic communication.

[0012] Collision detection (CD) mechanisms can detect collisions more quickly using orthogonal (e.g., time / frequency) 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 an FD preamble field following a conventional preamble field as defined in 802.11. FD STAs can handle collision preamble detection in different ways, depending on the relative priority.

[0013] In at least one embodiment, the mechanism can guarantee prioritized transmission after the processing of collision estimation within the BSS, such as the FD STA indicating priority in the control frame for collision avoidance, and / or the FD scheduler STA allowing high-priority traffic to be processed no later than low-priority traffic when estimating collisions within the BSS.

[0014] In at least one embodiment, the FD STA can initiate a transmission opportunity (TXOP) by preparing to transmit / clear transmit (RTS / CTS) exchange.

[0015] There are many possible implementations of the disclosed technology, examples of which are illustrated throughout the specification.

[0016] Other aspects of the technology described herein will be presented in the following sections of the specification, wherein the detailed description is intended to fully disclose preferred embodiments of the technology and not to limit it. Attached Figure Description

[0017] Referring to the following figures will provide a fuller understanding of the techniques described herein; the figures are for illustrative purposes only:

[0018] Figures 1 and 2 are diagrams comparing the signals that are thought to be transmitted with the signals that are actually received to illustrate various noise sources, including SI.

[0019] Figure 3 is a graph of SIC requirements based on analog and digital cancellation of the transmitted signal and its sub-components.

[0020] Figure 4 Figure 5 illustrates the FD preamble, which can be as follows: Figure 4 The frames shown are designated as FD independent training frames, or appended to existing frames as shown in Figure 5.

[0021] Figure 6 This is a block diagram of a full-duplex transceiver with analog and digital SICs according to at least one embodiment of the present disclosure, showing that there are RF / analog self-interference cancellation (SIC) elements and baseband / digital SIC elements between each pair of Tx chains and Rx chains.

[0022] Figure 7 is a hardware block diagram of a wireless station (STA) hardware according to at least one embodiment of the present disclosure.

[0023] Figure 8 It is a hardware block diagram of a station configuration such as that included in a multi-link device (MLD) hardware, according to at least one embodiment of the present disclosure.

[0024] Figure 9 This is an example network topology for illustrative purposes of asymmetric FD according to at least one embodiment of this disclosure.

[0025] Figure 10 This is an example network topology of a symmetric FD for illustrative purposes, according to at least one embodiment of this disclosure.

[0026] Figure 11 This is an example network topology with APs and multiple FD stations for illustrative purposes, according to at least one embodiment of this disclosure.

[0027] Figure 12 and Figure 13 This is a block diagram of the self-interference paths of dual-antenna elements and single-antenna elements, illustrating various forms of interference.

[0028] Figure 14 It is a signal diagram in which time-domain signals are orthogonal in FD preamble for collision detection according to at least one embodiment of the present disclosure.

[0029] Figure 15 It is a signal diagram of the preamble field and FD preamble in the time domain and frequency domain according to at least one embodiment of the present disclosure.

[0030] Figure 16 It is a signal diagram of frequency domain conflicts between different prioritized preambles according to at least one embodiment of the present disclosure.

[0031] Figure 17 It is a signal diagram indicating a conflict between frequency domain preambles of the same priority, according to at least one embodiment of the present disclosure.

[0032] Figure 18 It is a signal diagram for collision detection between a prioritized preamble and a conventional preamble according to at least one embodiment of the present disclosure.

[0033] Figure 19 It is for at least one embodiment of the present disclosure. Figure 18 Example network topology.

[0034] Figure 20 This is a flowchart illustrating how a transmitting station responds to collision detection according to at least one embodiment of the present disclosure.

[0035] Figure 21 This is an example network topology used to describe problem 6.2 according to at least one embodiment of this disclosure.

[0036] Figure 22 This is a communication diagram of Example 2-1, which illustrates HP traffic granting using PR+CDP frames according to at least one embodiment of this disclosure.

[0037] Figure 23 Example 2-1-0 is an example of at least one embodiment of this disclosure: a communication graph of FD AP triggering LP traffic without receiving any response from the granted HP traffic destination.

[0038] Figure 24 Example 2-1-1 is an example of at least one embodiment of this disclosure: a communication diagram of FD STA1 re-accessing the channel without receiving a trigger from FD.

[0039] Figure 25 Example 2-1-2 is an example of at least one embodiment of this disclosure: a communication diagram of HP traffic granting without PR+CDP frames.

[0040] Figure 26 Example 2-2 is an example of at least one embodiment of this disclosure: a communication graph of HP traffic granting when the AP has an LP.

[0041] Figure 27 Example 2-2 is an example network topology for describing example 2-2: HP traffic granting when the AP has an LP, according to at least one embodiment of this disclosure.

[0042] Figure 28 This is an example network topology used to describe extended examples 2-3: the impact of OBSS conflicts on OBSS interference, according to at least one embodiment of this disclosure.

[0043] Figure 29 This is an example network topology used to describe extended examples 2-3: the impact of OBSS conflicts on interference within the BSS, according to at least one embodiment of this disclosure.

[0044] Figure 30 This is an example network of a topology described according to at least one embodiment of the present disclosure, in which the AP may overestimate the collision.

[0045] Figure 31 The solution according to at least one embodiment of this disclosure Figure 30 Example of an overestimation of the conflict in communication diagram 2.

[0046] Figures 32-35This is a flowchart of FD AP operation when starting TXOP with a combination of P-RTS and P-CTS according to at least one embodiment of the present disclosure.

[0047] Figures 36-38 This is a flowchart of FD STA operation when starting TXOP with a combination of P-RTS and P-CTS according to at least one embodiment of the present disclosure.

[0048] Figure 39 Example 3-1 is an example of at least one embodiment of this disclosure: a communication diagram for HP traffic granting for a TXOP initiated by a PPDU.

[0049] Figure 40 Example 3-2 is an example of at least one embodiment of this disclosure: a communication diagram of HP traffic granting in the case of overestimated conflicts within the BSS.

[0050] Figure 41 Example 3-3 is an example of at least one embodiment of this disclosure: a communication diagram for HP traffic granting for TXOP initiated by PPDU when the AP has an LP.

[0051] Figure 42 Examples 3-4 are examples of at least one embodiment of this disclosure: a communication diagram for HP traffic granting for TXOP initiated by PPDU when the AP has an LP.

[0052] Figures 43-45 This is a flowchart of an FD AP starting a TXOP with a data PPDU according to at least one embodiment of the present disclosure.

[0053] Figures 46-47 This is a flowchart of a non-AP STA starting a TXOP with a data PPDU according to at least one embodiment of the present disclosure.

[0054] Figure 48 This is a data field diagram of a P-RTS frame according to at least one embodiment of the present disclosure.

[0055] Figure 49 It is from at least one embodiment of this disclosure Figure 48 Data field diagram of the PR request fields.

[0056] Figure 50 This is a data field diagram of a P-CTS frame according to at least one embodiment of the present disclosure.

[0057] Figure 51 It is in accordance with at least one embodiment of this disclosure Figure 50 The data field diagram of the PR control field is shown below.

[0058] Figure 52This is a data field diagram of a PR+CDP frame according to at least one embodiment of the present disclosure.

[0059] Figure 53 Is it like this? Figure 52 The data field diagram of the PR+CDP control field is shown below. Detailed Implementation

[0060] 1. Prior Art

[0061] The 802.11 FD Technology Interest Group (TIG) is discussing full-duplex (FD) technology, and at the time of writing, there are no standards for FD technology. The benefits of FD include the ability to simultaneously transmit and receive wireless signals sharing the same frequency resources; therefore, it offers the potential to double the spectral efficiency of bidirectional links compared to half-duplex links.

[0062] The challenge lies in effectively and adequately eliminating self-interference (SI) transmitted by the FD device and received by the same device through transceiver coupling and multipath reflection.

[0063] This technology has many use cases, including virtual reality (VR), artificial reality (AR), and telemedicine.

[0064] 1.1 Self-Interference Cancellation (SIC)

[0065] Figures 1 and 2 depict the spectrum (power and frequency) of the expected transmission (Figure 1) and the actual transmission (Figure 2). As a result, the signal initially transmitted by the STA is shown in Figure 1; however, the actual transmitted signal is shown in Figure 2. Numerous analog components in the transceiver distort the original signal shown in Figure 1 by adding transmitter noise and harmonics to the transmitted signal, resulting in the signal received as shown in Figure 2.

[0066] Figure 3 illustrates the self-interference cancellation (SIC) requirements for the FD to adequately eliminate any self-interference, thereby reducing the interference power to the level of the receiver noise floor (-90 dBm). The transmitted signal can be seen on the left side of the figure, including a 110 dB main signal, 80 dB harmonics, and 50 dB transmitter noise. The signal picked up by the receiver and the contribution of noise cancellation can be seen on the right side of the figure, comprising 60 dB of analog SIC cancellation and 50 dB of digital SIC cancellation. With this analog SIC cancellation, the receiver chain meets a peak-to-average power ratio (PAPR) of 10 dB at receiver saturation. The use of SIC results in a receiver noise floor of -90 dBm.

[0067] Therefore, the SIC should provide the following capabilities: (1) Any FD system should provide 110 dB of linear self-interference cancellation to reduce the SI to the receiver noise floor. This removes the strongest main signal component (110 dB) above the noise floor. (2) The FD system should reduce nonlinear harmonic components above the noise floor by 80 dB. (3) Any FD system should have an analog cancellation component that provides at least 50 dB of analog noise cancellation to eliminate transmitter noise. (4) Since the receiver (RX) chain in the radio may saturate if the input signal exceeds a certain level, which is determined by the analog-to-digital converter (ADC) resolution of the radio, as shown in Figure 3, since the transmitted SI can be as high as 20 dBm, the FD system needs to have analog cancellation that provides 60 dB of SI reduction to meet the Rx saturation level requirement, taking into account a 10 dB margin in peak-to-average power ratio (PAPR). In addition, digital cancellation that provides 50 dB of SI reduction results in a receiver noise floor of -90 dBm.

[0068] 1.2 Prioritized Communication

[0069] In 802.11, communication prioritization within an Access Class (AC) provides six transmit queues that are mapped to four Enhanced Distributed Channel Access Functions (EDCAF) to differentiate traffic flows within the same AC, thereby enabling finer prioritization between AC_VI or AC_VO flows.

[0070] 1.3. Previously Proposed Solutions

[0071] FD-assisted collision detection has been proposed to halt collision detection from concurrent transmissions from FD devices, thus avoiding time wastage caused by collisions. Further FD-assisted EDCA access with contention resolution has also been proposed to accelerate recovery from collisions. FD-assisted Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) has been proposed to improve the efficiency of existing MAC protocols. FD preambles have been proposed, requiring sufficient flexibility to facilitate Self-Interference Cancellation (SIC).

[0072] Figure 4 Figure 5 illustrates the FD preamble, which can be as follows: Figure 4 The frames shown are designated as FD independent training frames, or appended to existing frames as shown in Figure 5.

[0073] Self-interference cancellation (SIC) is proposed, which analyzes and / or proposes solutions to eliminate self-interference in FD transceivers.

[0074] Existing solutions require complete SIC (Self-Initial Communication). Furthermore, current collision detection solutions cannot distinguish between different priorities of collision signals, thus typically pausing transmissions from both sides to prevent further collisions.

[0075] 2. Contributions of this disclosure

[0076] A full-duplex (FD) collision detection method is described, which utilizes a prioritized preamble defined in a new FD preamble field. Collision detection using the prioritized preamble does not require full self-interference cancellation (SIC). Using FD-based collision detection without SIC improves the transmission efficiency of the detection STA, thus allowing it to pause the transmission of the remainder of the Physical Layer Protocol Data Unit (PPDU) to avoid further collisions.

[0077] In addition, this disclosure describes another conflict resolution method for priority flows, which grants earlier access to higher priority flows than lower priority flows when a conflict occurs within the BSS.

[0078] 3. Hardware Implementation Examples

[0079] Figure 6 This illustration depicts an example embodiment 10 of self-interference cancellation (SIC) hardware used in a station with a radio frequency front-end (RFFE) 30. This SIC hardware is used in a wireless local area network (WLAN), such as the STA shown below in Figure 7, and in... Figure 8 It is used in MLD as seen in [the context].

[0080] Tx digital BB 12 is the baseband transmit (Tx) signal. The baseband digital signal is modulated into a passband signal by a digital-to-analog converter (DAC) and upconverter (UC) 14, accumulating harmonics and transmitter noise. Before the transmit signal reaches the TX antenna 16, a small portion of the transmit signal, including transmitter noise, passes through circuit 15 for analog SiC.

[0081] The SiC circuit consists of parallel fixed lines of variable delay units 26a-26n and adjustable attenuators 28a-28n. These lines are then aggregated and summed, and the combined signal is subtracted from the signal on the receiving path.

[0082] The passband signal received from antenna 22 is subjected to SIC correction 23 and then passed through an analog-to-digital converter (ADC) and a down-converter (DC) 20. Digital SIC 24 is applied to the baseband digital signal from the ADC and DC to estimate the remaining residual self-interference, including the main TX SI after analog cancellation and any delayed reflections of the signal from the environment, thereby generating the receiver digital baseband signal 18.

[0083] Figure 7 illustrates an example embodiment 50 of STA hardware configured to execute the protocols of this disclosure. An external I / O connection 54 is preferably coupled to an internal bus 56 of circuitry 52. ​​A CPU 58 and a memory (e.g., RAM) 60 are connected to the internal bus 56 for executing programs that implement the communication protocol. The host computer houses at least one modem 62 supporting communication, which is coupled to at least one RF module 64, 68. Each RF module is connected to one or more antennas 69, 66a, 66b, 66c to 66n. RF modules with multiple antennas (e.g., antenna arrays) allow beamforming during transmission and reception. Thus, the STA can use multiple sets of beam patterns to transmit signals.

[0084] Bus 54 allows various devices to be connected to the CPU, such as sensors, actuators, etc. Instructions from memory 60 are executed on processor 58 to execute a program that implements the communication protocol, which is executed to allow the STA to function as an access point (AP) station or a regular station (non-AP STA). It should also be appreciated that the programming is configured to operate in different modes (TXOP holder, TXOP sharing participant, source, intermediate, destination, first AP, other APs, station associated with the first AP, station associated with other APs, coordinator, coordinated party, AP in OBSS, STA in OBSS, etc.) depending on its role in the current communication context.

[0085] Therefore, the STA HW is shown configured with at least one modem and associated RF circuitry for providing communication in at least one frequency band. This disclosure is primarily directed to the sub-6 GHz frequency band.

[0086] It should be appreciated that this disclosure can be configured with multiple modems 62, each coupled to any number of RF circuits. Generally, using a larger number of RF circuits will result in wider coverage in the antenna beam direction. It should be appreciated that the number of RF circuits and antennas used is determined by the hardware constraints of the specific device. When a STA determines that it does not need to communicate with neighboring STAs, a portion of the RF circuits and antennas can be disabled. In at least one embodiment, the RF circuitry includes frequency converters, array antenna controllers, etc., and is connected to multiple antennas controlled to perform beamforming for transmission and reception. Thus, a STA can use multiple sets of beam patterns to transmit signals, each beam pattern direction being considered an antenna sector.

[0087] Additionally, it should be noted that multiple instances of the station hardware shown in the figure can be combined into a multi-link device (MLD). An MLD will typically have a processor and memory for coordinating activities, while each STA within an MLD does not always require a separate CPU and memory.

[0088] Figure 8 Example embodiment 90 illustrates a multi-link device (MLD) hardware configuration. An MLD may include a soft AP MLD, which is an MLD consisting of one or more affiliated STAs acting as APs. The soft AP MLD should support multiple radio operations on 2.4 GHz, 5 GHz, and 6 GHz. Among the multiple radios, a basic link set is a pair of links that satisfy the simultaneous transmit and receive (STR) mode, for example, a basic link set (2.4 GHz and 5 GHz) or a basic link set (2.4 GHz and 6 GHz).

[0089] A conditional link is a link that forms a non-simultaneous transmit and receive (NSTR) link pair with one or more basic links. For example, these link pairs might include a 6GHz link as a conditional link corresponding to the 5GHz link when the 5GHz link is the basic link, and vice versa. Soft APs are used in various scenarios, including Wi-Fi hotspots and tethering.

[0090] Multiple STAs belong to a single MLD, each operating on links at different frequencies. The MLD has external I / O access for applications, connected to an MLD management entity 98 with a CPU 112 and memory (e.g., RAM) 114, to allow the execution of programs that implement communication protocols at the MLD level. The MLD can distribute tasks to and collect information from each subordinate station to which it is connected, exemplified here by STA1 92, STA2 94 to STA_N 96, and information sharing between subordinate STAs.

[0091] In at least one embodiment, each STA of the MLD has its own CPU 100 and memory (RAM) 102, which are coupled to at least one modem 104 via a bus 108. The modem 104 is connected to at least one RF circuit 106, which has one or more antennas. In this example, the RF circuit has multiple antennas 110a, 110b, 110c to 110n, such as in an antenna array. The modem, combined with the RF circuit and associated antennas, transmits / receives data frames with adjacent STAs. In at least one implementation, the RF module includes a frequency converter, an array antenna controller, and other circuitry for interfacing with its antennas.

[0092] It should be appreciated that each STA in an MLD does not necessarily need its own processor and memory, as STAs may share resources with each other and / or with the MLD management entity, depending on the specific MLD implementation. It should also be appreciated that the MLD diagrams above are given as examples and not as limitations, and that this disclosure can operate with a wide variety of MLD implementations.

[0093] 4. Architecture

[0094] 4.1. Example FD Implementation

[0095] Figure 9 The diagram illustrates an example embodiment 150 of an asymmetric FD architecture, in which FD AP 152 simultaneously transmits to FD STA1 154 and receives from FD STA2 156. In this case, the transmitted signal from the TX antenna of the FD AP generates self-interference and is received by the RX antenna of the FD AP.

[0096] Figure 10 This diagram illustrates an example embodiment 160 of a symmetric FD architecture, in which FD AP 162 transmits to and receives from another FD STA 164. The FD AP and FD STA receive self-interference generated by themselves.

[0097] 4.2. Network Topology

[0098] Figure 11 Example 170 illustrates the network topology used in the example by way of illustration rather than limitation, and this also applies to other topologies illustrated herein.

[0099] This example depicts three FD transceivers as FD AP 172, FD STA1 174, and FD STA2 176. FD AP, FD STA1, and FD STA2 are within each other's communication range (e.g., they can "hear" each other). FD STA1 and FD AP begin transmitting simultaneously. FD STA1 sends a PPDU to FD AP, while FD AP sends a PPDU to FD STA2. FD STA1 and FD AP undergo SI processing before SIC processing.

[0100] 5. Prioritized FD

[0101] In the scenario presented in this study, two FD STAs with different priorities within each other's range simultaneously transmit PPDUs. The preamble of the PPDU may contain an indication of priority.

[0102] Figure 12 and Figure 13Examples 180 and 200 illustrate the self-interference paths of dual-antenna and single-antenna systems. Figure 12 In the diagram, STA 182 is shown as having a transmit chain 184 to antenna 186 and a receive chain 188 from antenna 190. The figure depicts leakage between antennas, reflections attributable to the transceiver structure, and external reflection 192. Figure 13 In the figure, STA 182 is shown as having a transmit chain 184 coupled 202 to a single antenna 210, and a receive chain 188 coupled 204 to the same antenna 210. The figure depicts leakage between the transmit and receiver chains, reflections due to antenna mismatch, reflections due to the environment, and external reflections 212.

[0103] 5.1. Issues regarding conflict detection in priority-based function deployment (FD)

[0104] Self-interference cancellation (SIC) is one of the major challenges in 802.11 FD technology. Current FD techniques attempt to perform preamble-based collision detection after SIC is completed. However, there is no mechanism for performing preamble-based collision detection before SI channel estimation.

[0105] If the FD transceiver does not perform external reflection of SI (e.g.) Figure 12 and Figure 13 If the self-interference (SI) estimate (as shown in the figure) is not accurate, the FD transceiver will not be able to detect the presence of another signal.

[0106] Additionally, an FD transceiver may be unable to determine a collision based on a Cyclic Redundancy Check (CRC) error by hearing (receiving) its own preamble. The collision signal is too weak compared to the self-interference of its own preamble (e.g., encoded with MCS0).

[0107] 5.2. Collision Detection Solution for Prioritized FD

[0108] The following are methods to address these self-interference (SI) problems. (1) Include priority information in the FD preamble for collision detection resolution. In this case, collision detection does not require a complete SIC. (2) Each STA transmits an FD preamble carrying a priority signal in the PPDU, which is orthogonal to other priority signals carried by the FD preambles of other STAs. For example, orthogonal priority signals can be pre-configured. (3) When a collision is detected, the STA with the higher priority should retransmit the PPDU. (4) STAs with lower or the same priority should stop (pause) their transmissions and begin a backoff process after sensing that the medium is free again. (5) If a STA detects a collision but does not detect the priority of the colliding FD preamble, the STA should stop transmitting and begin a backoff process after sensing that the medium is free (available).

[0109] 5.2.1 Collision Detection Using Time-Domain Orthogonal Signals

[0110] The following description is based on Figure 11 In the topology shown, FD STA1 sends a PPDU to the FD AP, while the FD AP sends a PPDU to FDSTA2. The FD AP and FD STA1 receive signals during their transmissions. The received signals contain self-interference signals and interference signals from other STAs. The use of time-domain signals in the FD preamble is described below.

[0111] Figure 14 The diagram illustrates an example embodiment 220 of orthogonalizing (orthogonalizing) time-domain signals in an FD preamble for collision detection. Blocks 222 and 224 represent orthogonal frequency division multiplexing (OFDM) symbols (defined as data samples with a cyclic prefix (CP), in this case, the cyclic prefix is ​​approximately 3 μs in the time domain).

[0112] The window size, depicted as a vertical dashed box, represents the duration of the OFDM symbol duration without CP. Assume the detecting STA is FD STA1, and the colliding STA is FD AP. The symbol 222 above collides with the STA's FD preamble signal of priority 2. The symbol 224 below detects the STA's own FD preamble of priority 1.

[0113] 5.2.2. Example 1-1: Using the CD of TD quadrature signals

[0114] This example is based on the content in Section 5.2.1 and describes the collision detection process.

[0115] (a) Before transmitting the FD preamble, the STA, acting as the FD transceiver, does not perform channel estimation for self-interference (SI) from the external environment.

[0116] (b) The FD preambles of different STAs should be encoded before transmission, which means that they are multiplied by different column vectors of the P matrix before transmission so that they are orthogonal to each other.

[0117] As an orthogonal matrix (in this case) The P-matrix is ​​used for collision detection prior to self-interference cancellation. The P-matrix can be configured based on the existing 802.11 standard, or any other desired orthogonal matrix can be used.

[0118] The different priorities of the FD preamble are reflected by different columns of the P matrix. The P matrix is ​​pre-configured so that the STA can identify the priority represented by each column.

[0119] For example, [x0,x0] are two symbols that are part of the FD preamble, and the two x0 symbols are the same. STA1 (priority 1) multiplies [x0,x0] by the first column of the P matrix and emits [x0,x0]; STA2 (priority 2), which is a conflicting STA, multiplies [x0,x0] by the second column of the P matrix and then emits [x0,-x0].

[0120] (c) At this point, for each FD transceiver, detecting the presence of an FD preamble from another STA becomes a simple process while it is simultaneously transmitting and receiving FD preambles (which may occur before SI estimation).

[0121] For example, when STA1 transmits the first x0 symbol, it receives y0, which equals x0*h1 + x0*h2, where h1 and h2 are the channel coefficients for self-interference and the channel coefficients from STA2 to STA1, respectively. Note that [h1, h2] are unknown at this point before channel estimation. When STA1 transmits the second x0 symbol, it simultaneously receives y1, which equals x0*h1 - x0*h2. After receiving y0 and y1, STA1 can detect a collision by subtracting y1 from y0 (which equals 2*x0*h2). STA1 identifies this result as indicating a collision because if there were no collision, y0 (no collision) = x0*h1, and y1 (no collision) = x0*h1, then the result of y0 - y1 = 0.

[0122] (d) Once the STA detects a conflicting FD preamble, the STA should determine whether it should retransmit the frame or stop (pause) transmission and back off after sensing that the channel medium is idle. In at least one embodiment, this decision is made based on comparing its own priority with the priority indicated in the FD preamble received from the conflicting STA.

[0123] It should be recognized that different priorities are reflected by different orthogonal column vectors of the P matrix.

[0124] The prioritized FD preamble is encoded using the same P matrix. Based on the FD STA that detected the conflicting FD preamble in step (c), the FD STA can infer the vector / priority of the P matrix being used by the conflicting STA. For example, STA1 detects a conflict by subtracting y1 from y0 (as described in (c), this equals 2*x0*h2) and identifies this result as indicating a conflict. STA1 is using a [1,1] vector of the P matrix to represent priority 1. Using this information, STA1 can infer that the conflicting FD preamble is encoded using a [1,-1] vector of the P matrix representing priority 2.

[0125] If the STA has a higher priority, it should retransmit the PPDU. Otherwise, it should immediately stop transmitting the PPDU and back off after sensing that the medium is free.

[0126] 6. Carrier Frequency Offset (CFO) Issue Description

[0127] Significant (heavy) levels of carrier frequency offset (CFO) can disrupt the orthogonality between two signals, in which case the solution proposed above for transmitting time-domain orthogonal signals may suffer performance degradation.

[0128] Example: Consider the following collision detection using time-domain quadrature signals in the case of CFO. STA observes that the signal from another STA has a linear phase shift. Where f d This is a CFO of up to 40 ppm (parts per million) in the IEEE standard. With a subcarrier spacing of 78.125 kHz, the above-mentioned OFDM symbol duration is assumed to be 12.8 μs. An ultra-long cyclic prefix (CP) of approximately 3 μs (round-trip delay of 450 m BSS) is assumed. When f d At 39 kHz, or 7.8 ppm at 5 GHz, the phase offset between the second and first symbols of the conflicting FD preamble is π (before applying 1,-1 orthogonal overlay). Therefore, the conflicting FD preamble, along with self-interference, is completely canceled out. Consequently, the STA cannot detect the conflict in this situation.

[0129] The lack of synchronization in the problem description added from section 6.1 to section 5.1

[0130] If the two parties involved in a conflict do not have a synchronized center frequency, the time-domain orthogonal signals may completely lose their orthogonality.

[0131] 6.1.1. Solutions to the lack of synchronization

[0132] The following is a description of a solution according to this disclosure for overcoming the lack of proper center frequency synchronization. The FD preamble includes priority information embedded in the frequency domain. Different priorities can be carried by different subcarriers or tones of the FD preamble, which are separated by at least 40 ppm.

[0133] In the received baseband signal after analog cancellation and before digital cancellation (it should be noted that digital cancellation requires SI channel estimation), the STA sets the tone of its own FD preamble to zero in order to detect other STAs with different priorities.

[0134] If an FD STA detects a collision where the FD preamble has a lower priority than itself, it should retransmit the FD preamble and the remainder of the PPDU. Otherwise, it should stop (pause) transmission and begin a backoff process after sensing that the channel medium is idle again. In response to receiving the retransmitted FD preamble from a higher-priority STA, the receiver can resynchronize and estimate the channel.

[0135] 6.1.2 Prioritized FD preamble with orthogonality

[0136] As defined in the 802.11 standard, for 20 MHz, the center frequency tolerance for transmission should be ±20 ppm. It should be recognized that when frequency accuracy is described using parts per million (ppm), for example, an accuracy of 20 ppm indicates that the average frequency of the clock may deviate by 20 Hz for every 1 MHz of its specified value.

[0137] Different priorities can be carried by different subcarriers and / or tones of the transmitted FD preamble. Each STA transmits only one or more subsequent tones to carry the priority. The tone used to indicate the priority carries the symbol "1", while other tones carry the symbol "0".

[0138] When an FD device is transmitting, if the received prioritized FD preamble indicates a priority on a subcarrier and / or tone within 40 ppm of the subcarrier and / or tone carrying its own priority, the FD device cannot distinguish between simultaneously received prioritized FD preambles from itself or from conflicting STAs. Therefore, different priorities should be spaced at least 40 ppm apart on different subcarriers and / or tones of the FD preamble. A large space of more than 40 ppm between subcarriers carrying priority information allows for the detection of different priorities even in the case of CFO (Constant Forward) scenarios. Subcarriers and / or tones are pre-determined to represent specific priorities.

[0139] A STA transmitting its prioritized FD preamble can detect collisions from the received FD preamble by using an analog SIC to zero out the self-interference of its own priority signal. If the STA detects another priority signal after zeroing out, a collision is detected.

[0140] Traditional equipment may not be able to understand the priority tones interwoven in the priority preamble.

[0141] 6.1.2.1. Frequency-prioritized FD preamble symbols

[0142] Figure 15Example embodiment 230 illustrates the preamble field 232 and FD preamble 234 in the time and frequency domains. The preamble field can be the same as the preamble defined in the 802.11 baseline protocol. The FD preamble field follows the preamble field and is used to carry a specific priority. Different priorities, exemplified as 236a, 236b, 236c, and 236d, can be indicated in different subcarriers of the FD preamble, with a given interval (i.e., at least 40 ppm). By way of example and not limitation, three priorities are shown in the figure. It should be noted that the number of priorities is predetermined and agreed upon by the STA applying this type of preamble.

[0143] 6.1.2.2. Example 1-2: Frequency quadrature signals indicate CDs of different priorities

[0144] Figure 16 Example embodiment 240 illustrates frequency domain conflicts between preambles with different priorities. The figure shows, as... Figure 15 The preamble 242 and FD preamble 243 are shown. This example is based on... Figure 11 The same topology is described below. Assume FD STA1 transmits PPDUs with preambles 244a and 246a indicating priority 0; simultaneously, FD AP, acting as the interfering party, transmits PPDUs with preambles 244b and 246b indicating priority 1. As shown in the time domain, the two preambles from FD STA1 and FD AP are transmitted almost simultaneously. As a result, a collision may occur on FD STA2.

[0145] After the FFT, the FD STA1, indicating a priority of zero, sets a portion of the spurious signal associated with priority 0 transmissions 244a and 246a carried by the priority 0 tone, as well as from the interfering preamble indicating priority 1, to zero (after the analog SIC). The FD STA1 can then detect peaks in the priority 1 signal that indicate the presence of conflicting preambles with different priorities (priority 1) corresponding to tones 244b and 246b.

[0146] The FD AP performs the same actions as FD STA1, thus also detecting conflicting preambles with different priorities (priority 0). The lower-priority (e.g., priority 0) FD STA1 should then stop transmitting and begin backoff. In this discussion, it is assumed that priority 0 refers to a priority lower than priority 1. The higher-priority (e.g., priority 1) FD AP can retransmit, allowing the intended receiver to resynchronize and estimate the channel.

[0147] 6.1.2.3. Examples 1-3: Frequency quadrature signals indicate CDs of the same priority

[0148] Figure 17 The illustration depicts an example embodiment 250 indicating a conflict between frequency-domain preambles of the same priority. This example is also based on... Figure 11 The same topology is described below. Assume that FD STA1 transmits PPDUs with preambles 252a and 254a indicating priority 0. At the same time, the interfering FD AP transmits PPDUs with preambles 252b and 254b also indicating priority 0, and a collision may occur on FD STA2.

[0149] After the FFT, FD STA1 (indicating priority = 0) then zeros the pulse carried by the priority 0 tone (after the analog SIC) and performs the following operations.

[0150] (a) FD STA1 can also zero out interference priority 0 pulses from STA2 due to its very small CFO of less than 40 ppm. In this case, STA1 should not suspend transmission because it cannot distinguish whether the received peak in the priority 0 tone before SIC is caused by a conflicting preamble or whether its own transmitted preamble has experienced a Doppler effect introduced in the case of the Doppler effect. Therefore, a collision may occur on FD STA2, and further collision solutions for dealing with this type of collision problem are described in another section.

[0151] (b) If the CFO is significant (e.g., greater than 40 ppm), the FD STA1 can detect interference peaks from the FD AP, thereby identifying the interference peaks as indicating the presence of a conflicting preamble with the same priority (priority 0). In this case, the FD STA1 suspends transmission and backs off when the channel becomes idle again. The FD AP operates in the same manner as described for the FD STA1.

[0152] Several points should be noted regarding this diagram. In the case of the Doppler effect, STA1 still transmits a preamble indicating a PPDU with priority 0; there are no other interfering STAs. However, if the Doppler effect is considered, STA1 may still receive peak pulses on one or more other tones (different from the tone indicating priority = 0), which are reflections of its own transmission.

[0153] The received peak pulse may have one or more tones with the same priority as the transmitted one or more tones because the speed of the STA or the obstacle reflecting the signal is typically small compared to the speed of the wave. The frequency change between the received and transmitted frequencies is Δf = Δv * f0 / c, where f0 is the transmitted frequency and c is the wave speed in air (approximately 3 * 10⁻⁶). ^ 8m / sec).

[0154] 6.1.2.4. Examples 1-4: CD between priority preamble and traditional preamble

[0155] Figure 18 and Figure 19 Illustrated example embodiment 260 with different topologies 270.

[0156] exist Figure 19 In the image, we can see the FD AP272 receiving data from both FD STA1 274 and half-duplex STA2 276.

[0157] exist Figure 18 In this context, there is a preamble 252 with FD preamble 254 and a conventional preamble 253. Assume FD STA1 sends a PPDU with prioritized preambles 256a and 256b to the FD AP, where preambles 256a and 256b indicate priority on one or more priority 0 tones. Simultaneously, a non-FD STA2, acting as an interfering party, sends a PPDU with a conventional preamble to the FD AP; thus, a collision may occur on the FD AP.

[0158] It should be noted that traditional preambles use the preamble frame format defined in the 802.11 standard, which does not include subcarriers / tones for containing priority information.

[0159] After FFT window 258, FD STA1 (indicating priority = 0) zeros out the pulse carried by its priority tone (after analog SIC). FD STA1 cannot detect peaks indicating any predetermined priority. However, FD STA1 detects the presence of a collision signal. FD STA1 suspends transmission and backs off when the channel is idle. Non-FD STA2 uses the conventional CSMA / CD method to detect collisions.

[0160] Figure 20 The illustration depicts an example embodiment 280 of a transmitting station's response to collision detection, where the transmitting station can be an FD non-AP STA or an FD AP. Check 282 determines the priority level of the colliding FD preamble. If a condition is met, in box 284, it is checked whether the detected priority is lower than the priority of the detecting station. If the condition is met, a retransmission is performed 286.

[0161] If the condition is not met, the process returns to box 282, and then proceeds to box 290, where it determines whether a collision has occurred with the FD preamble. If no collision has occurred, then in box 288, the STA continues sending the remaining portion of the PPDU.

[0162] Otherwise, if the conditions in box 290 are met, proceed to box 292, at which point the STA stops transmitting and begins backoff when the channel is idle.

[0163] 6.2. Conflict resolution of priority FD

[0164] Problems may arise when an FD AP needs to prioritize high-priority traffic over low-priority traffic, and both traffic groups use the channel simultaneously, and the destination non-AP STA of the DL traffic and the source non-AP STA of the UL traffic are different, resulting in a conflict at the destination non-AP STA of the DL traffic.

[0165] 6.2.1 Topology of Problem 6.2

[0166] Figure 21 The diagram illustrates an example embodiment 300 of a topology in which FD AP 302 receives low-priority traffic from FD STA1 304 and sends high-priority traffic to FD STA2 306. FD STA1, FD STA2, and FD AP are within each other's communication range, with the aim of enabling AP to send high-priority traffic to STA2 and enabling STA1 to send low-priority traffic to AP.

[0167] FD STA 1 sends a Ready to Transmit (RTS) to FD AP, and FD AP simultaneously sends an RTS to FD STA 2. A collision occurs on FD STA 2, causing FD AP to fail to receive the CTS from FD STA 2, even though FD AP can receive the RTS from FD STA 1.

[0168] 6.2.2 Solution to Problem 6.2

[0169] A priority-based collision avoidance scheme is described. (1) The FD device can indicate priority in the control frame used for collision avoidance. (2) If the FD device sends a priority frame and receives another priority frame during transmission, the FD device recognizes the presence of intra-BSS interference and should prioritize the higher priority traffic. (3) The FD device estimating intra-BSS interference as described in Item 2 can broadcast a frame indicating the preferred priority that the FD device should prioritize. (a) Upon receiving a frame indicating the priority of the requested traffic; the FD device sending lower priority traffic suspends (stops) any transmission / retransmission. (b) The FD device sending higher or equal priority traffic should continue (retransmit) the process. (4) The FD AP can trigger a non-AP FD device to initiate the transmission of lower priority traffic. If the channel is idle for at least the PIFS duration after a non-AP FD device receives a broadcast frame indicating a preference for higher priority traffic, the non-AP FD device with lower priority traffic can re-access the channel without being triggered.

[0170] (5) If the FD device directly transmits the data PPDU instead of the RTS, it can simultaneously use the transmitted and received FD preambles to estimate intra-BSS collisions and determine the following procedures based on priority determination: (a) An FD device estimating the presence of an intra-BSS collision with a priority lower than its own should retransmit the PPDU. A portion of a Resource Element (RU) can be reserved for purposes other than serving the data PPDU; and more specifically for exchanging control messages between the AP and other STAs. (b) An FD device estimating the presence of an intra-BSS collision with a priority higher than its own is configured to stop transmitting the remainder of the PPDU unless it receives a control frame from a reserved RU or a non-reserved RU, such as a trigger from its destination. If the STA fails to receive any other frame exchange between other STAs, it can re-access the channel after EDCA backoff when the CCA is idle. (c) An FD device that only receives the preamble and not the remainder of the data PPDU can use a reserved RU (e.g., a pre-defined RU) to transmit a control frame to indicate the overestimated presence of an intra-BS collision. If the preamble source STA receives the control frame through a reserved RU, it can retransmit or trigger (through reserved RUs) the retransmission of a previously suspended PPDU that was overestimated as an intra-BSS collision signal.

[0171] 6.2-1 Example 2-1: Granting HP traffic using PR+CDP frames

[0172] Figure 22 An example embodiment 310 is illustrated with a diagram of an FD AP 312 with high priority (HP), an FD STA1 314 with low priority (LP), and an FD STA2 316. It is assumed that STA1 and STA2 can hear each other (communicate), and the process begins with RTS / CTS.

[0173] Topology and Figure 21 The topology shown is the same. The FD AP has high-priority (HP) traffic to be sent to FD STA2, and FD STA1 has low-priority (LP) traffic to be sent to the FD AP. The FD AP, FD STA1, and FD STA2 are within each other's communication range (e.g., they can hear each other). The FD AP and FD STA1 each initiate a transmission opportunity (TXOP) using prioritized control frames (e.g., prioritized RTS (P-RTS) 318 and 319).

[0174] (1) The AP receives P-RTS 319 (low priority traffic) from STA1 and simultaneously sends P-RTS 318 (high priority traffic) to STA2.

[0175] (2) The AP broadcasts a new frame with a priority request + collision detection probability (PR+CDP) of 320 to declare that the AP requests higher priority data transmission. The AP can therefore indicate the probability of collision detection in the new (PR+CDP) frame.

[0176] (3) After receiving the broadcast PR+CDP frame 320, STA1 recognizes that it does not meet the priority requirements, so it cancels its retransmission of P-RTS after the P-CTS timeout that started from the previous P-RTS.

[0177] (4) If the AP does not receive a P-CTS from STA2 before the P-CTS timeout, which is the period when the AP begins sending the previous P-RTS, the AP should retransmit another P-RTS 322 to STA2. It should be noted that the transmission time of the PR+CDP frame should not exceed the P-CTS timeout. If the transmission time of the PR+CDP frame exceeds the P-CTS timeout, the AP should retransmit the P-RTS during the SIFS period following the AP's transmission of the PR+CDP frame.

[0178] (5) STA2 receives the retransmitted P-RTS from AP and responds to AP with P-CTS 324. AP sends PPDU 326 to STA2 with Ack / BA 328 and 330.

[0179] (6) STA1 is considered to be busy 323 and therefore does not access the channel to (re)transmit PPDU unless it receives a trigger from the AP that allows STA1 to access the channel again.

[0180] Then, in the remainder of the diagram, the AP triggers STA 334, the STA accesses the channel and sends PPDU 338, and the sent PPDU is acknowledged by 340 and 342.

[0181] 6.2-1-0 Example 2-1-0: FDP triggers LP traffic when no response is received from the granted HP traffic destination.

[0182] Figure 23 Illustrated example of embodiment 410, embodiment 410 is Figure 22 The embodiment shown is a variation. The description is the same as in Example 2-1. The first four points of this example are the same as those described in Example 2-1; the difference here begins from the fifth element.

[0183] (5) STA2 failed to receive the retransmitted P-RTS 322 from AP, so it did not respond to AP with P-CTS.

[0184] (6) Since the AP did not receive the P-CTS from STA2 after the P-RTS was retransmitted, the AP sent a trigger frame 412 to STA1 so that STA1 could access the channel.

[0185] (7) STA1 receives the trigger frame from AP and sends UL PPDU 418 to AP, and receives Ack / BA 420 from AP during the transmission of UL PPDU.

[0186] (8) After confirming all UL PPDUs from STA1, the AP can retransmit P-RTS 424 to STA2. STA1 becomes CCA busy 426.

[0187] (9) STA2 successfully received P-RTS from AP and responded to AP with P-CTS 428.

[0188] (10) After receiving the P-CTS from STA2, the AP sends a DL PPDU 430 to STA2. The AP may receive an Ack / BA 432 from STA2 during the transmission of the DL PPDU.

[0189] (11)STA2 shall acknowledge to AP for all received DL PPDUs 434.

[0190] 6.2-1-1 Example 2-1-1: FD STA1 re-accesses the channel without receiving a trigger from the FD AP.

[0191] Figure 24 Illustrated Example 510, which has the same topology and description as Example 2-1. The first four points are the same as those described in Example 2-1; the following steps begin from this point.

[0192] (5) STA2 failed to receive the retransmitted P-RTS 322 from AP, so it did not respond to AP with P-CTS.

[0193] (6) The AP did not receive the P-CTS from STA2 after the P-RTS was retransmitted, so it did not send a trigger frame to STA1 to enable STA1 to access the channel.

[0194] (7) STA1 is in CCA busy during P-RTS 512. Then, when STA1 senses that CCA is idle, it re-accesses the channel by sending, for example, a CTS-to-self retransmitted P-RTS to the AP or by sending UL data after receiving a trigger frame from the AP. In this example, STA1 sends a retransmitted P-RTS to the AP 514, and STA2 is considered to be in CCA busy 516.

[0195] (8) The AP receives the P-RTS from STA1 and responds to STA1 with P-CTS 518 so that STA1 can send the LPUL PPDU.

[0196] (9) STA1 receives a P-CTS frame from AP and sends a UL PPDU 520 to AP, and then receives an Ack / BA 522 from AP during the transmission of the UL PPDU.

[0197] (10) After confirming that all 524UL PPDU 526 from STA1 are 524, AP may resend P-RTS526 to STA2.

[0198] (11) STA2 successfully received P-RTS from AP and responded to AP with P-CTS 530.

[0199] (12) After receiving the P-CTS from STA2, the AP sends a DL PPDU 532 to STA2. The AP can receive an Ack / BA 534 from STA2 during the transmission of the DL PPDU.

[0200] (13)STA2 acknowledges to AP for all received DL PPDUs 536.

[0201] 6.2-2-1-2 Example 2-1-2: HP Traffic Granting Without PR+CDP Frames

[0202] Figure 25 Illustrated Example 2-1-2: Example Implementation 610 in HP Traffic Granting without PR+CDP Frames. Topology and General Description with Figure 21 The same applies in this case. If both AP and STA1 estimate intra-BSS collisions and are pre-configured to grant higher priority to traffic, then after prioritizing based on the collision preamble, they can perform the following operations.

[0203] At the FD AP: (a) P-RTS 318 is simultaneously sent from AP (high priority) to STA2 and P-RTS 319 is received from STA1 (low priority). (b) After priority determination of the received preamble, the AP decides to continue sending traffic with higher priority. As a response to the P-RTS received from FD STA1 (LP), AP (high P) retransmits P-RTS 612 to STA2 instead of sending P-CTS. At this time, STA1 is in CCA busy 614. After receiving P-CTS 616 from STA2, AP sends PPDU 618, and STA2 acknowledges PPDU 618 620, 622. After this, AP sends trigger 624 to STA1, STA1 responds with PPDU 626, AP acknowledges PPDU 626 628, 630, while STA2 is in CCA busy 625.

[0204] At FD STA1: (a) P-RTS 319 is simultaneously sent from STA1 (low priority) to AP and P-RTS 318 is received from AP (high priority). (b) After priority determination based on the received preamble, STA1 stops sending to avoid conflict with higher priority traffic and enters CCA busy 614. (c) STA1 receives trigger 624 from AP (high priority) to send PPDU 626, and the reception of PPDU 626 is acknowledged 628, 630, while STA2 is in CCA busy 625.

[0205] 6.2-2-2 Example 2-2: HP Traffic Granting When the AP Has an LP

[0206] Figure 26 and Figure 27 Illustrated example embodiment 710 and example topology 750 of granting high-priority traffic when the AP has low-priority traffic.

[0207] exist Figure 27 In the middle, the topology is almost the same as Figure 21 The difference is that the traffic priority is reversed: FD AP has LP traffic to FD STA2 while FD STA1 has HP traffic to AP.

[0208] Now for reference Figure 26 Each station is within each other's range, and the FD AP and FD STA initiate TXOP with a priority control frame exemplified by the priority RTS (P-RTS).

[0209] (1) FD STA1 sends P-RTS 319(HP) to FD AP, while FD AP sends P-RTS 318(LP) to FD STA2. If FD STA1 and FD STA2 are within each other's communication range, P-RTS frames may collide at FD STA2.

[0210] (2) The FD AP first responds to STA1(HP) with P-CTS 712 and temporarily suspends the retransmission of P-RTS to STA2. At this time, STA2 is in CCA busy 714.

[0211] (3) After receiving P-CTS from AP, STA1 sends UL PPDU 716; and receives Ack 718 and 720 accordingly.

[0212] (4) After completing the transmission sequence with STA, AP retransmits P-RTS 722 to STA2. At this time, STA1 is in CCA busy 724.

[0213] (5) STA2 responds with P-CTS 726 after receiving P-RTS 722 from AP1.

[0214] (6) After receiving P-CTS from STA2, AP1 sends DL PPDU 728 to STA2; and receives Ack730 and 732 accordingly.

[0215] 6.2-2-3 Extended Example 2-3: The Impact of OBSS Conflicts

[0216] Figure 28 and Figure 29 The illustrations in examples 790 and 810 illustrate the impact of other Basic Service Set (OBSS) collisions. As we saw in examples 2-1-1, 2-1-2, and 2-2, the AP should grant higher priority traffic after collision resolution. However, a collision may be caused by OBSS interference, and the AP may not receive the colliding frame.

[0217] exist Figure 28 In this context, FD AP1 802 estimates the presence of OBSS interference. FD STA1 800 and FD STA2 798 are associated with FD AP1 802, where FD AP2 792 is an OBSS AP capable of generating the OBSS interference exemplified by signals 794 and 796. FD AP1 802 is sending high-priority traffic (HP) 804 to STA2 798.

[0218] While FD AP1 is sending high-priority traffic frame 804 to FD STA2, OBSS AP2 is transmitting some frames in the OBSS. The high-priority traffic frame from FD AP1 and the interfering frame 794 from FD AP2 collide at FD STA2. During the transmission of the high-priority traffic frame, AP1 did not receive the interfering frame from OBSS AP2 and cannot estimate the existence of the collision. In this situation, FD AP1 should retransmit the frame based on the conventional retransmission strategy.

[0219] exist Figure 29 In the process, the AP estimates the presence of interference within the BSS. Topology and OBSS interference are related to... Figure 28 The same as in the previous example, however, in this example, FD AP1 812 sends the same HP traffic 814 to FD STA2 798; but in this example, FD STA1 800 also sends a lower priority traffic frame 816 to FD AP1 812.

[0220] As a result of the above, collisions caused by intra-BSS interference and OBSS interference occur on FD STA2 798. In this case, FD AP1 can only estimate the presence of intra-BSS collisions by receiving a collision preamble indicating a lower priority during transmission.

[0221] Although FD AP1 cannot anticipate the existence of OBSS conflicts, it should still process the proposed protocol and grant higher priority traffic after performing conflict resolution.

[0222] 6.2-2-4 Example 2-4: AP Overestimation Conflict

[0223] Figure 30 The diagrams illustrate example cases 850a, 850b, 850c, and 850d where the AP might overestimate collisions. These cases depict different scenarios combining FD AP 854 with one or more stations such as FD STA1 852, FD STA2 856, and FD STA3 858. The AP may sometimes overestimate collisions within the BSS, as shown in cases 2 850b and 4 850d; in these cases, FD STA1 and FD STA2 are outside each other's communication range. However, the AP is unaware (e.g., there is no information indicating) that FD STA1 and FD STA2 cannot hear each other (cannot communicate with each other). Therefore, in both cases, the AP could estimate that there is a collision within the BSS; however, since the two stations are outside each other's range, there is no collision. Thus, it can be said that the AP overestimated the collisions.

[0224] In Case 1 850a, when the AP is transmitting to FD STA1 and FD STA1 is also transmitting to the AP, the AP can detect a spurious collision. However, without decoding the receiver address indicated in the header of the received PPDU, the FD AP cannot recognize that the received PPDU is addressed to itself. Once the AP detects the presence of the interference preamble, it will stop transmitting. But in reality, there is no collision within the BSS.

[0225] In scenario 3 850c, when the AP is transmitting to FD STA1 while FD STA1 is transmitting to FD STA2, the AP can detect a collision. The AP hears (detects) the interference preamble and can stop transmitting, thus avoiding a collision on FD STA2.

[0226] The next section discusses a solution using PR+CDP frames, which are suitable for overcoming overestimation of collisions.

[0227] Figure 31 Diagrammatic explanation of the solution Figure 30 Example 2 of the overestimation of the conflict, Example Implementation 910, where FDAP has high priority (HP) traffic to FD STA2 and FD STA1 has low priority (LP) traffic to FD AP. FD STA1 and FD STA2 are not in communication range with each other, but both can communicate with FD AP. FD AP and FD STA initiate TXOP using prioritized control frames, such as prioritized RTS (P-RTS).

[0228] (1) The AP receives P-RTS 319 from STA1 (lower priority) and simultaneously sends P-RTS 318 to STA2 (higher priority).

[0229] (2) The AP broadcasts a new frame (PR+CDP)912 to declare that the AP requests higher priority (indicating priority level) data transmission. (i) The AP may indicate the probability of collision in the new (RP+CDP) frame.

[0230] (3) STA1 and STA2 are outside each other’s communication range, which means there is no P-RTS conflict as mentioned in the previous steps. STA2 responds to the P-RTS sent by the AP with P-CTS 914, which overlaps in time with the PR+CDP frame received from the AP.

[0231] (4) A P-CTS from STA2 and a PR+CDP frame from AP collide on STA1; however, AP can receive P-CTS while AP is sending a PR+CDP frame.

[0232] (5) After the AP receives P-CTS 914 from STA2, the AP knows that it has overestimated the intra-BSS collision and that it should respond with P-CTS to the P-RTS previously received from STA1.

[0233] (6) Since STA1 did not receive PR+CDP frame 912, it should retransmit the P-RTS to the AP after the first P-CTS timeout. The retransmitted P-RTS to the AP may overlap with the P-CTS received from the AP in time, which may not have start / end alignment. In this case, STA1 will not retransmit the P-RTS again.

[0234] (7) Both STA1 and AP receive P-CTS from their destinations and begin sending one or more PPDUs 924, 925, 932, 933 to the destination simultaneously, provided that the origin and destination of each PPDU are aligned.

[0235] (8) Alignment of the start time of PPDU 922 and 930 can be achieved by: (a) the predetermined time from when the AP (as the collision estimator) sends the first P-RTS until it sends the P-CTS to STA1 (as the overestimated collision estimator) plus SIFS. (b) Alignment information can be sent, for example, the PPDU start time can be defined in the PR+CDP frame.

[0236] (9) Alignment of PPDU lengths 922 and 930 can be achieved by: (a) indicating in the first P-RTS; (b) indicating in the PR+CDP frame; (c) indicating in the management frame exchanged between the AP and STA.

[0237] (10) AP and STA2 receive PPDUs 924, 925, 932, 933 and respond with Ack / BA 928, 929, 936, and 937, provided that the start and end points of Ack / BA are aligned. (a) If the FD STA is sending a PPDU, it may receive another PPDU at the same time. In this case, Ack / BA should not be scheduled while the STA is sending a PPDU. There are several ways to achieve this: (i) Send a BA request at the end of each PPDU transmission. Only send a BA response after receiving the BA request. (2) Configure this in the first P-RTS frame or PR+CDP frame or in other management frames exchanged between AP and STA for reconfiguration.

[0238] The diagram then depicts the transmission of PPDU 938 from AP to STA2 while STA1 is in CCA busy 940, and the Ack 942 returning to AP.

[0239] Figures 32-35 Example embodiment 950 illustrates the FD AP operation when starting TXOP with a combination of P-RTS and P-CTS.

[0240] exist Figure 32 In this process, a set of checks are performed to determine whether a P-RTS was sent with priority (952); whether a P-RTS was received simultaneously (954); whether the P-RTS used for intra-BSS collision estimation has a lower priority (956); whether a PR+CDP was broadcast (958); and whether intra-BSS collisions were overestimated (960). If all these conditions are met, then in box 962, the AP responds to the lower-priority traffic source with a P-CTS.

[0241] If the 960 instruction conflict is not overestimated, then in Figure 33 In box 964, the AP retransmits 964P-RTS with the indicated priority and completes the 966 higher priority traffic TX / RX sequence.

[0242] Check 968 and then decide whether it should send a frame to the lower priority traffic source. If it should not send a frame, the process ends. Otherwise, if it decides to send a frame, the lower priority traffic sequence is completed in box 970, after which the process ends.

[0243] Return to Figure 32 If the first decision box 952 in the code does not meet the condition, then the execution will move to the next decision box. Figure 35 In box 988, it is determined whether a P-RTS has been received. If a P-RTS has been received, the AP responds with a P-CTS at 990, and the AP receives one or more PPDUs and a Block Ack Request (BAR) at 992, responding with an Ack / BA, after which the process ends. If it is determined at box 988 that a P-RTS has not been received, the process also ends.

[0244] Return to Figure 32 In the second decision box 954, if the condition is not met, the execution will move to... Figure 34 In box 976, a check is performed to determine if a P-CTS was received before the P-CTS timeout. If the condition is not met, a P-CTS timeout is registered (984), and a P-RTS (986) is retransmitted, after which a return is executed to retrieve the P-CTS data. Figure 32 The box starts at 952.

[0245] However, if the condition in box 976 is met, then in box 978, the AP sends a PPDU and receives an Ack / BA 980, then performs a check 982 to determine if the TXOP has not yet expired, and should send 982 more PPDUs. If more PPDUs need to be sent, the operation moves back to box 978; otherwise, the operation moves to... Figure 33 Box 966 is used to complete the higher priority TX / RX sequence.

[0246] Return to Figure 32 In the third decision box 956, if the condition is not met, then... Figure 34 In box 974, AP responds with P-CTS and performs a move to... Figure 33 The frame is 966.

[0247] Return to Figure 32 In the fourth decision box 958, if the condition is not met, then... Figure 34 In box 986, the AP retransmits the P-RTS, and the process returns to the beginning of the procedure.

[0248] Return to Figure 32 In the fifth decision box 960, if the conflict is overestimated, then in box 962, the AP responds to the lower priority traffic source with P-CTS and performs a move to... Figure 33 Box 972 in the document handles both higher-priority and lower-priority traffic simultaneously; see execution boxes 966 and 970.

[0249] Figures 36-38 The diagram illustrates the operation of FD STA when starting TXOP with the P-RTS and P-CTS combination.

[0250] exist Figure 36 In the process, a series of checks determine whether a P-RTS has been sent (1012); whether a P-RTS has been received simultaneously and whether it estimates a collision within the BSS (1014); and whether a PR+CDP frame has been received (1016).

[0251] If all these conditions are met, then in box 1018, STA stops retransmitting P-RTS and executes the move to Figure 37 Box 1022 checks whether, after it stopped (re)transmitting, a P-RTS or P-CTS or data with higher priority was transmitted within a short interval (e.g., the PIFS time period).

[0252] If the conditions are not met, then in box 1024, the STA uses CCA to send a frame to the same destination as the previously sent P-RTS to request processing for subsequent transmissions.

[0253] If the condition in box 1022 is met, then in box 1032, the STA stops its transmission or retransmits. In either case, execution moves to check 1026, which determines whether a frame for triggering and / or initiating PPDU transmission has been received. If this condition is met, then in box 1028, the STA completes its TX / RX sequence, and the process ends.

[0254] If the conditions of check 1026 are not met, then in box 1030, register the response frame timeout and then return to box 1022.

[0255] If the condition is not met, return to Figure 36 Box 1012, move to Figure 38 Box 1046 determines whether the STA has received a P-RTS with priority information.

[0256] If this condition is not met, the process ends.

[0257] If the conditions of check 1046 are met, the STA responds with P-CTS in box 1048, and then in box 1050, the STA receives one or more PPDUs and BARs and responds with Ack / BA, and then the process ends.

[0258] Return to check 1014; if the condition is not met, then... Figure 38 Check 1034 to determine if the STA received the P-CTS before the P-CTS timeout. If the P-CTS was not received in time, a timeout is registered in box 1042, and the STA retransmits the P-RTS with priority information in box 1044, and performs a move to... Figure 36 Box 1012.

[0259] Otherwise, if the condition in check 1034 is met, then in box 1036, the STA sends a PPDU and receives an Ack / BA 1038. Check 1040 then determines whether the TXOP is still valid (not expired) and whether more PPDUs need to be sent. If this condition is met, execution returns to box 1036. Otherwise, the TXOP has expired, and the process ends.

[0260] Return to Figure 36 In check 1016, if the condition is not met, execution moves to box 1020, which determines whether the STA has received a P-RTS frame indicating a higher or equal priority. If the condition is not met, execution moves to... Figure 37 The inspection was 1026.

[0261] 6.2-3-1 Example 3-1: HP traffic granting for TXOPs initiated by PPDU

[0262] The topology of this example is shown in Figure 21 In this context, FD AP 312 carries high-priority (HP) traffic to FD STA2 316, and FD STA1 314 carries low-priority (LP) traffic to the FD AP. The FD AP, FD STA1, and FD STA2 are within each other's communication range. The FD AP and FD STAs initiate TXOPs using PPDUs.

[0263] (1) At the beginning, STA1 (lower priority) sends a preamble 1114 indicating the priority of the traffic to the associated AP. At the same time, the AP (higher priority) also sends a preamble 1112 indicating the priority of the traffic to STA2.

[0264] (2) Both AP and STA1 estimated that there might be a collision within the BSS, since each sent its own preamble and received the other's preamble at approximately the same time.

[0265] (3) After estimating the collision within the BSS, STA 1 stops sending the remainder of the PPDU to the AP and is considered busy (CCA 1120). STA 1 waits for the sensing channel, or waits for a response or trigger frame from the AP to perform the next transmission.

[0266] (4) After the AP estimates a collision within the BSS, if the preamble of the collision indicates a lower priority than the AP's traffic, the AP may immediately or alternatively retransmit PPDU 1122 at PIFS after receiving the preamble of the collision.

[0267] (5) The AP may reserve some RUs (represented by the lower shaded area of ​​the PPDU block) to send selection control messages to other STAs that are not the destination of the current PPDU frame. If the preamble of the collision indicates a higher priority than the traffic of the AP, the procedure is performed as described in Examples 3-3 and 3-4, which will be presented in the following sections.

[0268] (6) STA2 receives DL PPDU 1122 from AP and may respond to AP with Ack / BA 1124, 1126 during its reception. The timing of the Ack / BA response should follow the schedule that can be set in BAR or other control / management frames (if any).

[0269] (7) If the AP does not receive Ack / BA from STA2 after / during the retransmission of PPDU, it can send trigger frame 1128 to STA1 to enable STA1 to access the channel.

[0270] (8) If STA1 receives neither a PPDU from AP nor a PPDU destined for AP from STA2, it can re-access the channel after EDCA backoff by sending, for example, a control frame or a retransmitted PPDU to AP, or wait for a trigger frame from AP to start sending TB-PPDU.

[0271] (9) STA1 senses CCA busy 1120 and therefore waits to access the channel to (re)transmit PPDU unless it receives a trigger from AP to enable STA1 to access the channel.

[0272] In this diagram, during PPDU 1122, STA2 sends ACKs 1124 and 1126. AP sends trigger 1128 to STA1. STA1 sends preamble (LP) 1132 followed by PPDU 1134. AP responds to STA1 with Acks 1136 and 1138; during this period, STA2 is in CCA busy state 1130.

[0273] 6.2-3-2 Example 3-2: HP Traffic Granting in Case of Overestimated Intra-BS Conflicts

[0274] Figure 40 This diagram illustrates an example embodiment 1210 with an HP AP and an LP STA1. STA1 and STA2 are not within communication range. The process begins with a data PPDU.

[0275] (1) At the beginning, STA1 (lower priority) sends a preamble 1214 indicating the priority of the traffic to the associated AP. At the same time, the AP (higher priority) also sends a preamble 1212 indicating the priority of the traffic to STA2.

[0276] (2) Both AP and STA1 estimated that intra-BSS collisions were possible because they simultaneously transmitted their own preambles and received preambles from another STA. However, they both overestimated intra-BSS collisions.

[0277] (3) After estimating the collision within the BSS, STA1 stops sending the remainder of the PPDU to the AP. It has identified the presence of a collision preamble indicating traffic with a higher priority than its own. STA1 should wait for the sensing channel, or wait for the AP's response or trigger frame 1222 to perform the next transmission.

[0278] (4) After the AP estimates a collision within the BSS, if the collision preamble indicates a lower priority than the AP's traffic, the AP immediately retransmits the 1220 PPDU to STA2, or it may be a PIFS after receiving the collision preamble. The AP may reserve some RUs (shown in the shaded part of the PPDU) to send control messages to some other STAs that are not destined for the ongoing PPDU transmission.

[0279] (5) Since there is no collision on STA2, it receives the preamble from the AP, but not the remainder of the data PPDU. Subsequently, it receives a retransmitted PPDU with the same preamble. In this case, it can use the reserved RU1218 and 1222 to send control frames such as CTS to the PPDU source, which can be an immediate response or SIFS after receiving the preamble.

[0280] (6) The AP receives control frame 1218 from STA2 in the reserved RU, during which time the AP may send DLPPDU to STA2. The AP can then use the reserved RU to send a trigger frame (e.g., PR+CDP) to STA1 to trigger preamble 1224 and UL PPDU 1226 from STA1. It should be noted that the trigger frame should contain PPDU endpoint alignment information to align the endpoints of the TB PPDU from STA1 to the AP and the UL PPDU from the AP to STA2.

[0281] (7) STA1 receives a control frame from AP in the reserved RU to trigger UL PPDU 1220. It should send UL PPDU 1224 and 1226 in accordance with the PPDU endpoint alignment rule 1225 from the received control frame.

[0282] (8) AP and STA2 receive PPDUs 1220 and 1226, and should respond simultaneously with Ack / BA 1230 and 1231, provided that the start and end points of Ack / BA are aligned to 1228. Ack / BA should not be scheduled while the STA is transmitting PPDUs. This can be achieved in several ways: (a) by sending a BA request at the end of each PPDU transmission. Only the BA responds after receiving the BA request. (b) by configuring this in a control frame (e.g., a PR+CDP frame) or in other management frames exchanged between AP and STA for reconfiguration.

[0283] The diagram shows additional PPDUs 1234 and 1235 aligned to 1232 between AP and STA2, followed by associated Acks 1238 and 1239 aligned to 1236. After this, another PPDU 1240 is sent to STA2, followed by Ack 1246, while STA1 is considered CCA busy 1242.

[0284] 6.2-3-3 Example 3-3: HP traffic granting for PPDU-initiated TXOPs when the AP has an LP

[0285] Figure 41 The diagram illustrates Example 1310 of Example 3-3, illustrating HP traffic granting for a TXOP initiated by a PPDU when the AP has low priority. The topology is as follows: Figure 30 As shown in case 2.

[0286] FD AP 312 has low-priority (LP) traffic to be sent to FD STA2 316, while FD STA1 314 has high-priority (HP) traffic to be sent to the FD AP. FD STA1 and FD STA2 are not within each other's range, but are both within the communication range of the FD AP. The FD AP and FD STAs initiate TXOPs using PPDUs.

[0287] (1) At the beginning, STA1 (higher priority) sends a preamble 1314 indicating the priority of the traffic to the associated AP. At the same time, the AP (lower priority) also sends a preamble 1312 indicating the priority of the traffic to STA2.

[0288] (2) Both AP and STA1 estimated that there might be intra-BSS collisions because they recognized that their own preambles were sent and received simultaneously.

[0289] (3) STA1 stops sending PPDUs after estimating intra-BSS collisions based on the preambles sent and received simultaneously (to avoid any possible further collisions). If STA1 has a higher priority, it can immediately retransmit the new preamble 1318 and PPDU 1322 to the AP, or retransmit the PPDU after receiving the colliding preamble via PIFS. STA1 can reserve some RUs for the AP (as shown in the shaded area of ​​the PPDU) to exchange control messages with other STAs.

[0290] (4) After the AP estimates the collision within the BSS, if the collision preamble indicates a higher priority than the AP's traffic, the AP stops sending the remainder of the PPDU.

[0291] (5) The AP receives UL PPDU 1322 from STA1 and may respond to STA1 with Ack / BA 1324 during its reception. The timing of the Ack / BA response shall follow the schedule that may be set in BAR or other control / management frames (if any).

[0292] (6) After completing the transmission sequence of the UL PPDU received from STA1, the AP can re-enter the channel after EDCA backoff to send the retransmitted preamble 1326 and PPDU 1330 to STA2, in response to Ack / BA 1332 and 1334. During this period, STA1 sees CCA busy.

[0293] 6.2-3-4 Example 3-4: HP traffic granting for PPDU-initiated TXOPs when the AP has an LP

[0294] Figure 42 The illustration includes an example embodiment 1410 with an FD AP 312 having an LP, an FD STA1 314 having an HP, and an FD STA2 316. STA1 and STA2 are not within each other's range, but are within the range of the AP. This example begins with a data PPDU.

[0295] Topology similar to Figure 30 The topology shown in Case 2 (850b) differs only in that the AP has LP traffic to STA2, while STA1 has HP traffic 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 TXOPs using PPDUs.

[0296] (1) At the beginning, STA1 (higher priority) sends a preamble 1414 indicating the priority of the traffic to the associated AP. At the same time, the AP (lower priority) also sends a preamble 1412 indicating the priority of the traffic to STA2.

[0297] (2) Both AP and STA1 estimated the possibility of intra-BSS collisions because they simultaneously transmitted their own preambles and received preambles from another station. However, in this case, they both overestimated intra-BSS collisions.

[0298] (3) After the AP estimates the collision within the BSS, if the collision preamble indicates a higher priority than the AP’s traffic, the AP stops sending the remainder of the PPDU unless it receives a control frame from the reserved RU indicating that the AP overestimated the collision within the BSS.

[0299] (4) STA1 stops transmitting the remainder of PPDU 1414 after estimating an intra-BSS collision based on the transmitted and received preambles (to avoid any possible further collisions). If STA1 has a higher priority, it can immediately retransmit preamble 1418 and PPDU 1426, or retransmit the PPDU after receiving the colliding preamble via PIFS. STA1 can reserve some RUs for the AP (as shown in the shaded portion of the PPDU) to exchange control messages with other STAs.

[0300] (5) In this case, STA2 receives the preamble from AP but not the remainder of the data PPDU. If STA2 does not receive anything and the channel is idle for another preamble duration (and possibly an additional PIFS interval), STA2 can immediately send a control frame to AP with the reserved RU or with an additional SIFS delay to indicate that it has received the preamble.

[0301] (6) The AP receives control frame 1422 from STA2 on the reserved RU. Control frame 1422 indicates that the AP has overestimated the intra-BSS collision. The AP may retransmit preamble 1424 and PPDU 1428 to STA2, which is the destination of the overestimated intra-BSS collision. The AP should send a DL PPDU to STA2, where the endpoint of the PPDU is aligned with the UL PPDU received from STA1.

[0302] (7) AP and STA2 receive PPDUs and should respond simultaneously with Ack / BA 1430 and 1431, provided the Ack / BA start and end points are aligned. Ack / BA should not be scheduled while the STA is sending PPDUs. This can be achieved in several ways: (a) by sending a BA request at the end of each PPDU transmission. Upon receiving a BA request (BAR), only a BA response is used. (b) by configuring this in a control frame (e.g., a PR+CDP frame) or in other management frames exchanged between AP and STA for reconfiguration.

[0303] The diagram then shows additional PPDUs, including PPDU 1436 with preamble 1432 and PPDU 1436 to STA2, and PPDU 1436 with preamble 1434 and PPDU 1436 to AP, followed by Ack 1438 and 1439.

[0304] Figures 43-45 The diagram illustrates example embodiment 1470 where the FD AP begins a TXOP with a data PPDU. At check 1472, the AP estimates that the conflict within the BSS has a lower priority than itself.

[0305] exist Figure 43If the condition is met, then in box 1474, the AP retransmits the PPDU, reserving some RUs for other STAs. Then, in check 1476, the check determines whether the AP receives an overestimated control frame indicating a collision within the BSS from the destination via the reserved RUs.

[0306] If the condition is met in box 1476, then in Figure 44 In box 1482, the AP sends a control (trigger) frame in the reserved RU to trigger the estimated conflicting STA to send a trigger-based PPDU (TB-PPDU). Then in box 1484, the AP maintains PPDU end-point and / or start-point alignment and Ack / BA alignment according to the schedule (if any), and then the process ends.

[0307] Return to check 1476; if the condition is not met, proceed to the next step. Figure 44 In box 1478, the current PPDU transmission sequence is terminated, and a trigger is sent to another STA that is estimated to have a lower priority in the collision. Then in box 1480, the AP sends an Ack / BA in response to the received PPDU, and the process ends.

[0308] Return to check 1472; if the condition is not met, proceed to the next step. Figure 45 In box 1486, the AP stops sending the remainder of the PPDU. Then, at check 1488, the AP determines whether it has received an overestimated control frame indicating a collision within the BSS from the destination STA via the reserved RU.

[0309] If the conditions are met, in box 1490, the AP retransmits the DL PPDU. During this period, the AP may be receiving a UL PPDU and performing a move to... Figure 44 Box 1484 in the middle.

[0310] Returning to box 1488, if the condition is not met, then in box 1492, the AP responds to the received PPDU by sending an Ack / BA. Then in box 1494, the AP ends the current PPDU transmission sequence and can send a trigger to another STA that is estimated to have a lower priority in the conflict, and then the process ends.

[0311] Figure 46 and Figure 47 Illustrated example 1510 of a non-AP STA starting a TXOP with a data PPDU.

[0312] Check 1512 determines whether the non-AP STA has received the preamble but not the remainder of the data PPDU. If this condition is met, in box 1520, the STA sends a control frame using the reserved RU to indicate an overestimated intra-BSS collision, and then in box 1522, the non-AP STA responds to the PPDU by sending an Ack / BA, and then the process ends.

[0313] Returning to check 1512, if the condition is not met, then at check 1514, the STA checks whether the estimate of the conflict within the BSS has a lower priority than itself.

[0314] If the condition is met, in box 1516, the STA retransmits the PPDU while reserving some RUs for other STAs, and in box 1518, the STA maintains the PPDU end-point and / or start-point alignment and Ack / BA alignment according to the schedule (if a schedule exists), and then the process ends.

[0315] Return to check 1514; if the condition is not met, proceed to the next step. Figure 47 In box 1524, the STA stops sending the remainder of the PPDU. Check 1526 determines whether a control frame triggering the UL PPDU has been received from the destination STA (AP) via a reserved RU or a non-reserved RU.

[0316] If the conditions are not met, then in box 1530, if the STA cannot receive frame exchanges between other STAs, the STA will retransmit the PPDU after EDCA backoff when the channel is CCA idle, and then the process ends.

[0317] If this condition is met, proceed from check 1526 to box 1528, STA reissues UL PPDU, and then proceeds to... Figure 46 Box 1518 in the middle.

[0318] 7. Data Structures

[0319] 7.1. Preambles with Priority

[0320] Traditional preambles contain some reserved bits. (See also: [link to previous section]) Figure 4 Regarding the FD training sequence in Figure 5, the following should be noted: Bit 14 (B14) of the HE-SIG-A field in HE SU PPDU and HE ER SU PPDU is reserved. Bit 7 (B7) of the HE-SIG-A field in HE MU PPDU is reserved. In both cases, these reserved bits can be used to indicate high priority (stage 1) and low priority (stage 0).

[0321] In the following description, specific bit states used to indicate conditions / information are provided as examples rather than limitations.

[0322] Another approach is to implement priority information in the FD preamble following the conventional preamble shown in Figure 5. The priority subfield can be included within the FD preamble field. Alternatively, different priorities can be embedded in one or more different subcarriers with a certain space (i.e., at least 40 ppm) above the tone corresponding to the bit range of the FD preamble field.

[0323] 7.2. P-RTS (Prioritized RTS)

[0324] Figure 48 This diagram illustrates an example of a 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 sending STA requests to be transmitted, as well as scheduling information such as PPDU alignment. The STA receiving the P-RTS frame must identify the required traffic priority and must follow the PPDU and / or Ack alignment rules requested in the frame. Frame control indicates frame control information corresponding to different frame types. The Duration / ID field sets the NAV value at the receiving STA, which protects against any subsequent data, administrative, or response frames plus any additional overhead frames in a single protection context; otherwise, it sets the NAV protected against multiple frames until the estimated end of the sequence of multiple frames in a multi-protection context.

[0325] The RA field of this frame is the address of the STA that is the intended direct receiver. The TA field is the address of the STA that sent the 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 procedures after sending / receiving this frame.

[0326] Figure 49 The illustration is from Figure 48 Example embodiment 1610 of the PR control field. The Priority Request subfield indicates the priority of the traffic requested by the STA sending the frame. PPDU and ACK SYN Request subfields: If set to 1, the STA sending or receiving the frame should align the start of the PPDU and the start of the ACK / BA that is the response to each received PPDU.

[0327] The PPDU start time subfield indicates the option to start the PPDU TX / RX after the current TX / RX frame. If set to 0: This means no specific start time is indicated, and the STA begins sending the PPDU after SIFS following the completion of all control frame exchanges with its destination (e.g., from sending a P-RTS to receiving a P-CTS as a response to the P-RTS). If set to 1: This indicates a specific start time. For example, for an FD STA after receiving the frame, this is after 1 PR+CDP frame duration + SIFS + 1 CTS frame duration + SIFS. For an FD STA sending the frame, since it starts counting after sending the frame, it needs to add another SIFS to the previous calculation. PPDU Duration Alignment Subfield: Set to 1 to indicate that the PPDU should be padded to end simultaneously, as indicated by the L-SIG field of the preamble.

[0328] 7.3. P-CTS (Prioritized CTS)

[0329] Figure 50 Illustrated Example 1630 of a P-CTS Frame. The FD STA sends a P-CTS frame in response to receiving a P-RTS frame. The P-CTS frame is shown to have frame control, duration ID, RA, PR control, and FCS.

[0330] Figure 51 Diagram Explanation Figure 50 Example embodiment 1650 of the PR control field shown. The PR control field indicates priority request information for subsequent procedures after sending / receiving the frame. The priority request subfield indicates the priority for which the P-CTS is a response, which should be the same as the priority specified in the responding P-RTS frame.

[0331] The other fields are the same as those in the P-RTS overview.

[0332] 7.4.PR+CDP Frame Format

[0333] Figure 52 Example 1670 illustrates a PR+CDP frame. When an FD AP detects a collision within a BSS, it can broadcast a new frame (PR+CDP) to declare that the AP requests higher priority (indicating priority level) data transmission. It can also indicate scheduling rules such as PPDU alignment and / or ACK alignment in the frame.

[0334] A STA receiving a PR+CDP frame and having previously sent a prioritized control frame (such as a P-RTS AP) should compare the priority declared by the AP carried in the PR+CDP frame with the priority of the traffic it requests to send to the AP. If the AP declares a higher priority than its own, it should suspend the retransmission of the previous control frame.

[0335] Figure 53 Example embodiment 1690 illustrates the PR+CDP control field. The PR+CDP control field indicates priority requests and collision detection probability information, along with corresponding control information, for subsequent procedures after sending / receiving the frame. The priority request subfield indicates the priority that the STA sending the frame requests to process first. The collision detection probability subfield indicates the estimated probability of a collision within the BSS, and its possible values ​​are 0 or 1. The PPDU and ACK SYN request subfields can be set to 1 to indicate that the STA sending or receiving the frame should align the start of the PPDU and the start of the ACK that responds to each received PPDU.

[0336] PPDU Start Time Subfield: Indicates the option to start the TX / RX PPDU after the TX / RX frame. If set to 0: This means that no specific start time is indicated, and the STA begins sending the PPDU after completing all previous control frame exchanges with its destination (from sending RTS to receiving CTS, and may include additional frame exchanges for canceling overestimation of collision detection) at SIFS.

[0337] If set to 1: This indicates a specific start time, for example, for an FD STA that receives the frame, after 1 CTS frame duration + SIFS. For an FD STA that sends the frame, since it starts counting after sending the frame, it needs to add another SIFS to the previous calculation.

[0338] PPDU Duration Alignment Subfield: Set to 1 to indicate that the PPDU should be padded to end simultaneously, as indicated by the L-SIG field of the preamble. Other fields are the same as those defined in the P-RTS frame.

[0339] 8. General Scope of the Embodiments

[0340] Embodiments of this technology can be described herein with reference to flowchart illustrations of methods and systems according to embodiments of this technology, and / or may also be described as processes, algorithms, steps, operations, formulas, or other computational descriptions implemented as computer program products. In this regard, each block or step of the flowchart, and combinations of blocks (and / or steps) in the flowchart, as well as any process, algorithm, step, operation, formula, or computational description, can be implemented by various means, such as hardware, firmware, and / or software, including one or more computer program instructions embodied in computer-readable program code. It should be appreciated that any such computer program instructions can be executed by one or more computer processors (including, but not limited to, general-purpose or special-purpose computers), or other programmable processing means to produce a machine, such that the computer program instructions executing on the computer processor or other programmable processing means create components for implementing specified functions.

[0341] Therefore, the flowchart boxes, and the descriptions of processes, algorithms, steps, operations, formulas, or calculations illustrated herein, support combinations of components for performing a specified function, combinations of steps for performing a specified function, and computer program instructions (e.g., computer-readable program code logic components) for performing a specified function. It should also be understood that each box of the flowchart, and any descriptions of processes, algorithms, steps, operations, formulas, or calculations illustrated herein, and their combinations thereof, can be implemented using a dedicated hardware-based computer system, or a combination of dedicated hardware and computer-readable program code, to perform the specified function or step.

[0342] Furthermore, these computer program instructions (e.g., embodied in computer-readable program code) may also be stored in one or more computer-readable storage devices that can direct a computer processor or other programmable processing apparatus to operate in a particular manner, causing the instructions stored in the computer-readable storage device to produce an article of manufacture including instruction components that implement the functions specified in the blocks of the flowchart. The computer program instructions may also be executed by a computer processor or other programmable processing apparatus to cause a series of operational steps to be performed on the computer processor or other programmable processing apparatus, thereby producing a computer-implemented process, such that the instructions, which execute on the computer processor or other programmable processing apparatus, provide steps for implementing the functions specified in the blocks, processes, algorithms, steps, operations, formulas, or calculation descriptions of the flowchart.

[0343] It should also be recognized that, as used herein, the terms “programming” or “executable program” refer to one or more instructions that can be executed by one or more computer processors to perform one or more functions described herein. Instructions may be embodied in software, firmware, or a combination of both. Instructions may be stored locally on a non-transitory medium or remotely, such as on a server, or all or part of the instructions may be stored both locally and remotely. Remotely stored instructions may be downloaded (pushed) to the device by a user or automatically downloaded (pushed) to the device based on one or more factors.

[0344] It should also be recognized that the terms processor, hardware processor, computer processor, central processing unit (CPU), and computer, as used herein, are used synonymously to refer to a device capable of executing instructions and communicating with input / output interfaces and / or peripheral devices, and the terms processor, hardware processor, computer processor, CPU, and computer are intended to include single or multiple devices, single-core and multi-core devices, and variations thereof.

[0345] Based on the description herein, it should be appreciated that this disclosure includes various implementations of the described technology, including but not limited to the following:

[0346] An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuit, the wireless communication circuit acting as a station (STA) wirelessly communicating with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol, the wireless communication circuit being configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA); (b) a processor for the STA; (c) a non-temporary memory storing instructions executable by the processor to communicate with other STAs and fulfill different roles in the communication protocol; and (d) wherein, when executed by the processor, the instructions perform one or more steps of preamble-based collision detection, including: (d)(i) generating an orthogonal preamble by the STA acting as a full-duplex (FD) STA, the orthogonal preamble containing embedded traffic priority information, and processing the preamble, including: (d)(i)(A) ​​detecting a priority lower than its own priority. When a collision occurs, the STA retransmits the preamble and its associated Physical Layer Protocol Data Unit (PPDU); (d)(i)(B) when a collision occurs with a preamble of equal or higher priority than its own or with no priority, the STA stops transmitting and begins backoff after sensing that the medium is idle; and (d)(i)(C) if no collision is detected, PPDU transmission continues; (d)(ii) after processing collision estimates within the Basic Service Set (BSS), transmission is prioritized, including: (d)(ii)(A) ​​indicating the priority in each control frame transmitted for collision avoidance; and (d)(ii)(B) when the STA, operating as a scheduler, estimates collisions within the BSS, higher priority traffic is allowed to be processed no later than lower priority traffic.

[0347] An apparatus for wireless communication in a network, the apparatus comprising: (a) a wireless communication circuitry acting as a station (STA) to wirelessly communicate with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol, the wireless communication circuitry being configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA); (b) a processor for the STA; (c) a non-temporary memory storing instructions executable by the processor to communicate with other STAs and fulfill different roles in the communication protocol; and (d) wherein, when executed by the processor, the instructions perform one or more steps of collision detection based on a preamble, including: (d)(i) by acting as a FD The STA generates orthogonal preambles in the time and / or frequency domains, containing embedded traffic priority information, and processes the preambles, including: (d)(i)(A) ​​when a conflicting preamble with a lower priority than its own is detected, the STA retransmits the preamble and its associated Physical Layer Protocol Data Unit (PPDU); (d)(i)(B) when a conflicting preamble with a priority equal to or higher than its own or with no priority is detected, the STA stops its transmission and begins backoff after sensing medium idleness; and (d)(i)(C) if no conflict is detected, it continues to transmit PDUs. The remaining portion of the PDU; (d)(ii) prioritizing transmissions after processing intra-basic service set (BSS) collision estimates, including: (d)(ii)(A) ​​indicating priority in each control frame transmitted for collision avoidance; and (d)(ii)(B) allowing higher priority traffic to be processed no later than lower priority traffic when the STA, operating as a scheduler, estimates intra-BSS collisions; (d)(iii) initiating a transmission opportunity (TXOP), and broadcasting a frame to indicate the preferred priority for requests to be processed for the TXOP when intra-basic service set (BSS) interference is estimated to be present.

[0348] A method for wireless communication in a network includes: (a) a wireless communication circuit acting as a station (STA) communicating wirelessly with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol, wherein the wireless communication circuit is configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) and is configured to perform a role in preamble-based collision detection; (b) by a FD The STA generates an orthogonal preamble containing embedded traffic priority information and processes the preamble, including: (b)(i) when a conflicting preamble with a priority lower than its own is detected, the STA retransmits the preamble and its associated Physical Layer Protocol Data Unit (PPDU); (b)(ii) when a conflicting preamble with a priority equal to or higher than its own or with no priority is detected, the STA stops its transmission and begins backoff after sensing that the medium is idle; and (b)(iii) if no conflict is detected, the STA continues to transmit the remainder of the PPDU; (c) after processing the conflict estimation within the Basic Service Set (BSS), the transmission is prioritized, including: (c)(i) indicating the priority in each control frame transmitted for conflict avoidance; and (c)(ii) when the STA, operating as a scheduler, estimates conflicts within the BSS, allowing higher priority traffic to be processed no later than lower priority traffic.

[0349] A WLAN apparatus includes: (a) a full-duplex (FD) station (STA) capable of initiating new preamble-based collision detection without performing self-interference (SI) estimation and providing new collision resolution estimation and scheduling for prioritized communications; (b) detecting collisions faster using orthogonal preambles without performing self-interference channel estimation; (c) embedding priority information in the preamble; (d) a priority level that can be predetermined and agreed upon by all FD STAs and can be embedded in an FD preamble field, such as following a conventional preamble field as defined in 802.11; (e) detecting a colliding preamble with a priority lower than its own and retransmitting the preamble and its PPDU; otherwise, ceasing transmission and initiating backoff upon sensing an idle channel; (f) if the FD STA detects a collision without detecting the priority of the colliding preamble, wherein the STA should cease transmission and initiating backoff upon sensing an idle channel; and (g) if no collision is detected, wherein the STA continues to transmit the remainder of the PPDU.

[0350] Any of the foregoing implementations of the apparatus or method wherein the preamble-based collision detection is performed without performing self-interference cancellation (SIC) channel estimation.

[0351] Any of the aforementioned implementations of the apparatus or method, wherein priority information is embedded in a preamble and is predetermined and / or agreed upon by a station on the wireless network.

[0352] Any of the aforementioned implementations of the apparatus or method, wherein priority information is embedded in a preamble following a conventional preamble field as defined in 802.11.

[0353] Any of the foregoing implementations of the apparatus or method wherein the orthogonal preamble is orthogonal in the time domain, or in the frequency domain, or in both the time and frequency domains.

[0354] Any of the aforementioned implementations of the apparatus or method, wherein the orthogonal preamble in the time domain carries an orthogonal priority signal, the orthogonal priority signal being orthogonal to other priority signals carried by the preambles of other STAs.

[0355] Any of the foregoing implementations of the apparatus or method wherein the orthogonal priority signal is pre-configured and wherein center frequency synchronization between transmitters is requested.

[0356] Any of the foregoing implementations of the apparatus or method wherein the orthogonal preamble in the frequency domain includes priority information that can be embedded in different subcarriers spaced at least 40 ppm apart.

[0357] Any of the foregoing implementations of the described apparatus or method, wherein the STA sets the tone of its own FD preamble to zero in order to detect other STAs with different priorities.

[0358] Any of the foregoing implementations of the apparatus or method wherein the FD STA is capable of initiating a transmission opportunity (TXOP) using Prepare to Transmit (RTS), Clear to Transmit (CTS), and message exchange.

[0359] Any of the foregoing implementations of the apparatus or method wherein, when interference within the basic service set (BSS) is estimated to be present, a broadcast frame is used to indicate the preferred priority of the request to be processed for the TXOP.

[0360] Any of the foregoing implementations of the apparatus or method wherein, upon receiving a frame indicating the requested traffic priority, each FD STA on the network performs an action based on which traffic priority it is processing: (i) when processing traffic with a priority lower than the requested priority, they cease any transmission and retransmission; and (ii) when processing traffic with a priority higher than or equal to the requested priority, each FD STA continues its respective transmitter and receiver processing.

[0361] Any of the foregoing implementations of the apparatus or method wherein the STA is an FD access point (AP) that triggers a non-AP FD STA on the network to initiate the transmission of lower priority traffic, and if the channel is idle for at least the PIFS duration after the non-AP FD STA receives a broadcast frame indicating a preference for higher priority traffic, then the non-AP FD STA with lower priority traffic is allowed to re-access the channel without being triggered.

[0362] Any of the foregoing implementations of the apparatus or method wherein, after processing the requested priority traffic, the FD STA broadcasting the frame containing the requested priority information then sends another frame to the conflicting FD STAs on the network with estimated lower priority traffic, to indicate that they are able to begin sending and receiving lower priority traffic.

[0363] Any of the foregoing implementations of the apparatus or method, wherein the FD STA initiates a transmission opportunity (TXOP) by transmitting a data PPDU.

[0364] Any of the foregoing implementations of the apparatus or method wherein the simultaneously transmitted and received preamble is used to estimate intra-BSS (basic service set) collisions and to make the following procedural decisions based on priority determination: (a) if an intra-BSS collision with an estimated priority lower than its own exists, then retransmit the PPDU; (b) if an intra-BSS collision with an estimated priority higher than its own exists, then stop transmitting the PPDU unless a control frame is received from a reserved RU or a non-reserved RU; and (c) if a preamble is received but no data PPDU portion is available, then a control frame is transmitted on a reserved RU to indicate that an overestimated intra-BS collision exists.

[0365] In any of the aforementioned implementations of the apparatus or method, for an overestimated intra-BSS collision, the STA that generated the preamble in the network receives the control frame through a reserved RU and retransmits or triggers a retransmission of a previously terminated PPDU with lower priority, which was overestimated as an intra-BSS collision signal.

[0366] Any of the foregoing implementations of the apparatus or method wherein, upon receiving a frame indicating the requested traffic priority, each FD STA on the network performs an action based on which traffic priority it is processing: (i) when processing traffic with a priority lower than the requested priority, they cease any transmission and retransmission; and (ii) when processing traffic with a priority higher than or equal to the requested priority, each FD STA continues its respective transmitter and receiver processing.

[0367] Any of the foregoing implementations of the apparatus or method wherein prioritization of transmission is guaranteed after processing intra-BSS collision estimation: (a) the FD STA should indicate the priority in the control frame used for collision avoidance; (b) when intra-BSS collisions are estimated, the FD scheduler STA should allow higher priority traffic to be processed no later than lower priority traffic.

[0368] Any of the foregoing implementations of the apparatus or method wherein the FD STA uses orthogonal preamble codes in the time and / or frequency domains.

[0369] Any of the foregoing implementations of the apparatus or method, wherein for time-domain orthogonal preambles: (i) each STA transmits an FD preamble of a PPDU carrying a priority signal, the priority signal being orthogonal to other priority signals carried by the FD preambles of other STAs; and the orthogonal priority signals are pre-configured; and (ii) a request is made to synchronize the center frequency between the transmitters.

[0370] Any of the foregoing implementations of the apparatus or method wherein, for frequency-domain orthogonal preambles: (i) priority information may be embedded in different subcarriers of the FD preamble that are at least 40 ppm apart in the frequency domain; (ii) in the baseband after analog cancellation and before digital cancellation (note that digital cancellation requires SI channel estimation), the STA sets the tone of its own FD preamble to zero in order to detect other STAs with different priorities; (iii) since this application is CFO tolerant, center frequency synchronization between transmitters may not be requested.

[0371] In any of the foregoing implementations of the apparatus or method, wherein the FD STA can initiate a TXOP using RTS / CTS switching: (a) an FD STA estimating the presence of interference within the BSS can broadcast a frame indicating its requested preferred priority for processing; (b) upon receiving the frame indicating the requested traffic priority, the FD STAs perform different operations based on the priority of the traffic they are processing: (i) for FD STAs processing traffic with a priority lower than the requested priority, they should stop any transmission / retransmission; (ii) for FD STAs processing traffic with a priority higher than or equal to the requested priority, they should continue their TX / RX processes; (c) an FD AP can trigger a non-AP FD device to initiate the transmission of lower-priority traffic; wherein if the channel is idle for at least the PIFS duration after the non-AP FD device receives the broadcast frame indicating a preference for higher-priority traffic, the non-AP FD device with lower-priority traffic can re-access the channel without being triggered; (d) after finishing processing the requested priority traffic, the FD STA that broadcast the frame with the requested priority information can send a frame to a conflicting FD device with lower-priority traffic. The STA sends another frame to begin a lower-bandwidth transmission and reception process.

[0372] In any of the aforementioned implementations of the apparatus or method, an FD STA that stops (re)transmitting after receiving a broadcast frame with a request priority higher than its own can access the medium if, after a certain period of time following the stop (re)transmission, for example, after one PIFS, it does not receive or detect any frame from the STA handling the requested priority traffic.

[0373] Any of the aforementioned implementations of the apparatus or method, wherein an FD STA that overestimates the collision within the BSS should become aware of the overestimation after receiving a response frame from the estimated collision destination.

[0374] Any of the foregoing implementations of the apparatus or method wherein the FD STA finds that it has overestimated the collision within the BSS and should respond with a frame to the overestimated collision source that has sent a frame (e.g., an RTS with priority) but has not yet received a response frame.

[0375] Any of the foregoing implementations of the apparatus or method wherein FD STAs with different traffic priorities have received responses from their destinations allowing their transmission. They may simultaneously begin transmitting one or more PPDUs to their destinations, provided that the start and end points of the PPDUs are aligned or the PPDU lengths are aligned.

[0376] Any of the foregoing implementations of the apparatus or method wherein the alignment of the start time of the PPDU can be achieved by: (a) adding an additional SIFS based on a predetermined time from when the collision detection STA sends the first frame (e.g., P-RTS) until it receives a response frame (e.g., P-CTS); or (b) defining alignment information, such as the PPDU start time, in a broadcast frame indicating the request priority.

[0377] Any of the foregoing implementations of the apparatus or method wherein alignment of the PPDU length can be achieved by: (a) indicating the start of a new TXOP in a first frame, such as a P-RTS; (b) indicating it in a broadcast frame indicating a priority request; and (c) indicating it in an exchangeable management frame between the AP and STA.

[0378] Any of the foregoing implementations of the apparatus or method, wherein the destination FD STA receiving the PPDU as described in the preceding claims shall respond simultaneously with Ack / BA in the case of Ack / BA alignment; wherein the transmitted Ack / BA shall not overlap with any concurrent TX / RX of the PPDU at the Ack / BA destination.

[0379] Any of the foregoing implementations of the apparatus or method wherein the Ack / BA alignment is achieved by: (a) sending a BA request per PPDU, wherein the FD STA responds with only a BA when a BA request is received; (b) being configured to start a new TXOP in a first frame, such as a P-RTS, as described in the preceding claims; or being configured in a broadcast frame indicating the priority of the request or in an exchangeable management frame between the AP and STA.

[0380] Any of the foregoing implementations of the apparatus or method, wherein the FD STA can initiate a TXOP by sending a data PPDU.

[0381] Any of the foregoing implementations of the apparatus or method, wherein the simultaneously transmitted and received preambles are used to estimate intra-BSS collisions and determine the following process based on priority determination: (a) an FD device that estimates the existence of an intra-BSS collision with a priority lower than its own should retransmit the PPDU; and wherein a portion of the RU may not be reserved for servicing data PPDUs for that device, but instead be used to exchange control messages between the AP and other STAs; (b) an FD device that estimates the existence of an intra-BSS collision with a priority higher than its own should stop transmitting the remainder of the PPDU unless it receives a control frame from a reserved RU or a non-reserved RU, such as a trigger from its destination. If the STA does not hear any other frame exchange between other STAs, it can re-access the channel after EDCA backoff when CCA is idle; and wherein (c) an FD device that receives only the preamble and not the remainder of the data PPDU can use a reserved RU (which may be a predetermined RU) to send a control frame to indicate an overestimated intra-BSS collision; wherein if the preamble source STA receives the control frame through the reserved RU, it can retransmit or trigger (through the reserved RU) a previously terminated PPDU with lower priority that has been overestimated as an intra-BSS collision signal.

[0382] Any of the foregoing implementations of the apparatus or method wherein PPDUs from different streams can be received simultaneously in the FD STA, and they should respond simultaneously with Ack / BA while being Ack / BA aligned.

[0383] Any of the foregoing implementations of the apparatus or method wherein the Ack / BA alignment is achieved by: (a) sending a BA request per PPDU, wherein the FD STA responds with only a BA when a BA request is received; (b) configuring to start a new TXOP in a first frame as described in the preceding claims; or configuring in a control frame indicating the priority of the request or in an exchangeable management frame between the AP and STA.

[0384] Any of the foregoing implementations of the apparatus or method wherein alignment of the PPDU endpoint can be achieved by: (a) indicating the start of a new TXOP in a first frame; (b) indicating in a control frame that indicates a priority request and is exchanged in a reserved RU; and (c) indicating in a management frame that is exchangeable between the AP and STA.

[0385] The term “implementation” as used herein is intended to include, but is not limited to, embodiments, examples, or other forms of practicing the techniques described herein.

[0386] The singular forms “a,” “one,” and “the” used in this article may include objects referred to in the plural form, unless the context clearly indicates otherwise. Unless explicitly stated otherwise, referring to an object in the singular does not imply “there is one and only one,” but rather “one or more.”

[0387] The wording structures such as “A, B and / or C” in this disclosure indicate that A, B or C, or any combination of items A, B and C, may be present. Wording structures such as “at least one of…” that previously listed a set of elements indicate the presence of at least one of that set of elements, including any possible combination of the applicable listed elements.

[0388] References to the terms "embodiment," "at least one embodiment," or similar embodiments in this specification indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of this disclosure. Therefore, these different embodiment phrases do not necessarily refer to the same embodiment or a specific embodiment different from all other embodiments described. The term "embodiment" should be interpreted as meaning that a particular feature, structure, or characteristic of a given embodiment can be combined in any suitable manner in one or more embodiments of the disclosed apparatus, system, or method.

[0389] As used in this article, the term "group" refers to a collection of one or more objects. Thus, a group of objects can include, for example, a single object or multiple objects.

[0390] Relational terms such as first and second, top and bottom are used only to distinguish one entity or action from another, and do not necessarily require or imply any actual such relationship or order between these entities or actions.

[0391] The terms “comprising,” “having,” “including,” “containing,” or any other variation thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes, has, comprises, or contains elements does not solely include those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Elements preceding “comprising…,” “having…,” “including…,” or “containing…” do not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes, has, comprises, or contains that element, unless further construed.

[0392] The terms “approximately,” “approximately,” “generally,” “substantially,” and “about,” or any other version thereof, used in this document are used to describe and indicate small variations. When used in conjunction with an event or situation, these terms may refer to instances in which the event or situation occurs precisely, and instances in which the event or situation occurs approximately. When used in conjunction with a numerical value, these terms may refer to a range of variation less than or equal to ±10% of that value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, “substantially” alignment may refer to a range of angular variation less than or equal to ±10°, such as less than or equal to ±5°, less than or equal to ±4°, less than or equal to ±3°, less than or equal to ±2°, less than or equal to ±1°, less than or equal to ±0.5°, less than or equal to ±0.1°, or less than or equal to ±0.05°.

[0393] In addition, quantities, ratios, and other numerical values ​​may sometimes be presented in range format throughout this document. It should be understood that this range format is used for convenience and brevity, and should be flexibly interpreted to include not only the values ​​explicitly specified as the limits of the range, but also all individual values ​​or subranges covered within that range, as if each value and subrange were explicitly specified. For example, a ratio in the range of approximately 1 to approximately 200 should be understood to include the explicitly listed limits of approximately 1 and approximately 200, as well as individual ratios such as approximately 2, approximately 3, and approximately 4, and subranges such as approximately 10 to approximately 50, approximately 20 to approximately 100, etc.

[0394] The term "coupled" as used in this article is defined as a connection, but not necessarily a direct connection or a mechanical connection. A device or structure that is "configured" in a certain way is at least configured in that way, but it can also be configured in ways not listed.

[0395] Benefits, advantages, solutions to problems, and any elements that may lead to or make any benefit, advantage, or solution appear or become more apparent should not be construed as key, essential, or fundamental features or elements of the technology described herein or any or all claims.

[0396] Furthermore, in the foregoing disclosure, features may be grouped together in various embodiments for the purpose of simplification. This approach should not be construed as reflecting an intention that the claimed embodiments require more features than are expressly listed in each claim. The subject matter of the invention may lie in fewer features than all the features of a single disclosed embodiment.

[0397] An abstract of this disclosure is provided to enable the reader to quickly determine the nature of the technical disclosure. The abstract is provided so that it will not be used to interpret or limit the scope or meaning of the claims.

[0398] It should be recognized that, following the filing of this application, the practice of some jurisdictions may require the deletion of one or more portions of this disclosure. Therefore, the reader should consult the filed application for the original content of this disclosure. Any deletion of the contents of this disclosure should not be construed as a waiver, loss, or dedication to the public of any subject matter of the originally filed application.

[0399] The following claims are therefore incorporated into this disclosure, each claim being an independent subject matter for protection.

[0400] Although the description herein contains numerous details, these details should not be construed as limiting the scope of this disclosure, but rather as merely illustrative of some embodiments of the presently preferred embodiments. Therefore, it should be appreciated that the scope of this disclosure fully encompasses other embodiments that may become apparent to those skilled in the art.

[0401] All structural and functional equivalents of the elements of the disclosed embodiments that are known to those skilled in the art are expressly incorporated herein by reference and are included in the claims. Furthermore, the elements, components, or method steps in this disclosure are not intended to be given to the public, whether or not they are expressly stated in the claims. Claim elements herein should not be construed as “component + function” elements unless the element is expressly stated using the phrase “component for…”. Claim elements herein should not be construed as “step + function” elements unless the element is expressly stated using the phrase “step for…”.

Claims

1. An apparatus for wireless communication in a network, the apparatus comprising: (a) A wireless communication circuit, which acts as a station (STA) and communicates wirelessly with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol. The wireless communication circuit is configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA). (b) The processor of the STA; (c) Non-temporary memory storing instructions that can be executed by the processor to communicate with other STAs and perform different roles in the communication protocol; as well as (d) When the instruction is executed by the processor, it performs one or more steps of preamble-based collision detection, including: (i) An orthogonal preamble is generated by the STA, which is a full-duplex FD STA, the orthogonal preamble containing embedded traffic priority information, and the preamble is processed, including: (A) When a conflicting preamble with a lower priority than its own is detected, the STA retransmits the preamble and its associated physical layer protocol data unit (PPDU). (B) Upon detecting a conflicting preamble with a priority equal to or higher than its own priority, or with no priority, the STA stops transmitting and begins backoff after sensing that the medium is idle; and (C) If no collision is detected, continue sending PPDU; (ii) Prioritizing transmissions after processing collision estimation within the Basic Service Set (BSS), including: (A) Indicate priority in each control frame sent for collision avoidance; and (B) When a STA operating as a scheduler estimates intra-BSS conflicts, it is permissible to process higher-priority traffic no later than lower-priority traffic.

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

3. The apparatus according to claim 1, wherein priority information is embedded in a preamble and is predetermined and / or agreed upon by a station on the wireless network.

4. The apparatus according to claim 1, wherein priority information is embedded in a preamble following a conventional preamble field as defined in 802.

11.

5. The apparatus according to claim 1, wherein the orthogonal preamble is orthogonal in the time domain, or in the frequency domain, or in both the time and frequency domains.

6. The apparatus according to claim 5, wherein the orthogonal preamble in the time domain carries an orthogonal priority signal, the orthogonal priority signal being orthogonal to other priority signals carried by the preambles of other STAs.

7. The apparatus according to claim 6, wherein the orthogonal priority signal is pre-configured, and wherein center frequency synchronization between transmitters shall be requested.

8. The apparatus according to claim 5, wherein the orthogonal preamble in the frequency domain includes priority information that can be embedded in different subcarriers spaced at least 40 ppm apart.

9. The apparatus according to claim 8, wherein the STA sets the tone of its own FD preamble to zero in order to detect other STAs with different priorities.

10. The apparatus according to claim 1, wherein the FD STA is capable of initiating a transmission opportunity (TXOP) by preparing to transmit the RTS, clearing the transmission CTS, and exchanging messages.

11. The apparatus of claim 10, wherein when interference is estimated to exist within the Basic Service Set (BSS), a broadcast frame is used to indicate the preferred priority of the request to be processed for the TXOP.

12. The apparatus of claim 1, wherein upon receiving a frame indicating the requested traffic priority, each FD STA on the network performs an action based on which traffic priority it is processing: (i) when processing traffic with a priority lower than the requested priority, it stops any transmission and retransmission; and (ii) when processing traffic with a priority higher than or equal to the requested priority, each FD STA continues its respective transmitter and receiver processing.

13. The apparatus of claim 1, wherein the STA is an FD AP that triggers a non-access point AP FD STA on the network to initiate the transmission of lower priority traffic, and allows the non-AP FD STA with lower priority traffic to re-access the channel without being triggered if the channel is idle for at least the PIFS duration after the non-AP FD STA receives a broadcast frame indicating a preference for higher priority traffic.

14. The apparatus of claim 1, wherein after processing the requested priority traffic, the FD STA that broadcast the frame containing the requested priority information then sends another frame to the conflicting FD STAs on the network with estimated lower priority traffic to indicate that they are able to begin transmitting and receiving lower priority traffic.

15. The apparatus according to claim 1, wherein the FD STA initiates a transmission opportunity (TXOP) by transmitting a data PPDU.

16. The apparatus of claim 15, wherein the simultaneously transmitted and received preamble is used to estimate intra-BSS collisions and to make the following procedural decisions based on priority determination: (a) retransmitting the PPDU when an intra-BSS collision with an estimated priority lower than its own exists; (b) stopping the transmission of the PPDU when an intra-BSS collision with an estimated priority higher than its own exists, unless a control frame is received from a reserved RU or a non-reserved RU; and (c) transmitting a control frame on a reserved RU to indicate the existence of an overestimated intra-BS collision when a preamble is received but no data PPDU portion is available.

17. The apparatus of claim 16, wherein for an overestimated intra-BSS collision, the STA that generated the preamble in the network receives the control frame through a reserved RU and retransmits or triggers a retransmission of a previously terminated PPDU with lower priority, which was overestimated as an intra-BSS collision signal.

18. An apparatus for wireless communication in a network, the apparatus comprising: (a) A wireless communication circuit, which acts as a station (STA) and communicates wirelessly with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol. The wireless communication circuit is configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA). (b) The processor of the STA; (c) Non-temporary memory storing instructions that can be executed by the processor to communicate with other STAs and perform different roles in the communication protocol; as well as (d) When the instruction is executed by the processor, it performs one or more steps of preamble-based collision detection, including: (i) The STA, acting as the FD STA, generates orthogonal preambles in the time and / or frequency domains, containing embedded traffic priority information, and processes the preambles, including: (A) When a conflicting preamble with a lower priority than its own is detected, the STA retransmits the preamble and its associated physical layer protocol data unit (PPDU). (B) Upon detecting a conflicting preamble with a priority equal to or higher than its own priority, or with no priority, the STA stops transmitting and begins backoff after sensing that the medium is idle; and (C) If no collision is detected, continue sending the remainder of the PPDU; (ii) Prioritizing transmissions after processing collision estimation within the Basic Service Set (BSS), including: (A) Indicate priority in each control frame sent for collision avoidance; and (B) When a STA operating as a scheduler estimates intra-BSS conflicts, it is permissible to process higher-priority traffic no later than lower-priority traffic. (iii) Initiate a transmission opportunity (TXOP) and, when interference is estimated to exist within the basic service set (BSS), broadcast a frame to indicate the preferred priority of the request to be processed for the TXOP.

19. The apparatus of claim 18, wherein upon receiving a frame indicating the requested traffic priority, each FD STA on the network performs an action based on which traffic priority it is processing: (i) when processing traffic with a priority lower than the requested priority, it stops any transmission and retransmission; and (ii) when processing traffic with a priority higher than or equal to the requested priority, each FD STA continues its respective transmitter and receiver processing.

20. A method for wireless communication in a network, comprising: (a) The wireless communication circuitry of a station STA communicates wirelessly with other STAs on a wireless local area network (WLAN) using the IEEE 802.11 protocol. The wireless communication circuitry is configured to support Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) and is configured to perform a role in preamble-based collision detection. (b) The STA, acting as the FD STA, generates an orthogonal preamble containing embedded traffic priority information, and processes the preamble, including: (i) When a conflicting preamble with a lower priority than its own is detected, the STA retransmits the preamble and its associated physical layer protocol data unit (PPDU). (ii) Upon detecting a conflicting preamble with a priority equal to or higher than its own priority, or with no priority, the STA stops transmitting and begins backoff after sensing that the medium is idle; and (iii) If no collision is detected, continue sending the remainder of the PPDU; (c) Prioritizing transmissions after processing collision estimation within the Basic Service Set (BSS), including: (i) Indicate priority in each control frame sent for collision avoidance; and (ii) When a STA operating as a scheduler estimates intra-BSS conflicts, it is permissible to process higher-priority traffic no later than lower-priority traffic.

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