Method and system for multi-access point cooperation

Abstract

According to a first aspect of the present disclosure, a method by which a station (STA) sends a multi-AP cooperation parameter change message to an access point (e.g., an associated access point) is discussed. The STA, which may be a mobile STA, may be in a better location than the AP itself for detecting conditional changes that may affect the effectiveness or even accessibility of multi-AP collaboration. A second aspect of the present invention provides an AP-to-AP negotiation process for multi-AP collaboration. This aspect may be used alone, may also be used in conjunction with the first aspect, or may be used to improve other multi-AP collaboration methods and systems. In some embodiments, this process includes each AP maintaining a current database of neighboring APs based on previous multi-AP collaboration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. patent application No. 17 / 877,421, filed on July 29, 2022, the contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to the field of communication networks, and in particular to a system and method for communicating using multiple access points (multi-AP). One aspect of the present invention provides a method and system for WLAN multi-AP collaboration. Background Information

[0003] Wireless access points (APs), such as those in wireless local area networks (WLANs) based on the IEEE 802.11 standard (commonly known as Wi-Fi), have traditionally operated in standalone mode. As end users’ service requirements become more stringent and the demands on devices and applications running on these devices are increasing, it has become extremely challenging for APs operating in standalone mode to achieve these goals. IEEE 802.11be (Wi-Fi 7) introduces the scenario of collaborative APs (multi-AP collaboration), where neighboring APs can collaborate in time, frequency, power, and airspace for resource allocation.

[0004] Multi-AP collaboration can be achieved through a group of non-co-located APs that have intersections in network coverage and operating frequency bands. For example, for these non-co-located APs, their respective network coverage areas and operating frequency bands overlap. Therefore, for devices located in the overlapping coverage area, one or more APs in the group of non-co-located APs can provide communication services to them. Current multi-AP collaboration proposals rely on the AP to request multi-AP collaboration based on the local conditions it detects. For example, an AP can use a transmission opportunity (TXOP) to obtain channel access, and can initiate collaboration with a second AP to allow the two APs to perform multi-user transmissions during the TXOP.

[0005] Prior art multi-AP collaboration proposals only involve APs. However, from a service provisioning perspective, configuring collaboration between APs is challenging and sometimes unnecessary because there is no clear expectation or need for collaboration. In addition, the AP performs necessary detection with a group of STAs and other potential collaborative APs. This results in low efficiency and high overhead (i.e., round-trip time for information reception).

[0006] Therefore, a system and method for multi-AP collaboration is needed to eliminate or alleviate one or more limitations of the prior art.

[0007] The purpose of providing this background information is to disclose information believed by the applicant to be potentially relevant to the present invention. It is not necessary to admit, nor should it be construed, that any of the above information constitutes prior art against the present invention. Summary of the invention

[0008] The prior art multi-AP cooperation proposal only involves APs. The present invention proposes to introduce stations (STAs) into the cooperation process.

[0009] According to a first aspect of the present invention, a method for a station (STA) to send a multi-AP cooperation parameter change message to an access point (e.g., an associated access point) is discussed. STA, which may be a mobile STA, may be in a better position than the AP itself to detect changes in conditions that may affect the effectiveness or even desirability of multi-AP cooperation. Therefore, the STA may send a message reporting the detected conditions related to multi-AP cooperation. In some embodiments, such a message may request the initialization of multi-AP cooperation, wherein such a message may be in response to a trigger event detected by the STA. In response to such a trigger event, the STA may actively analyze the service requirements of the STA and send a multi-AP cooperation parameter change message. In some embodiments, the STA may actively or preferentially perform an analysis of the service requirements of the STA and send a multi-AP cooperation parameter change message. It will be understood that this type of active or preferential analysis may be performed using a specific method or various methods or machine learning-based tools.

[0010] Therefore, the embodiment implements a user-centric multi-AP collaboration scheme, which includes one or both of an intelligent STA reporting mechanism and an AP to AP negotiation process. In some embodiments, multi-AP collaboration is triggered by STA and initiated by AP. In some embodiments, the intelligent STA reporting mechanism allows STA to explicitly express its own resource requirements by identifying QoS requirements, where QoS requirements can be defined based on aspects including but not limited to data rate, latency, reliability, and efficiency. In some embodiments, the AP to AP negotiation process achieves a flexible and context-aware collaboration level through information sharing between APs.

[0011] In some embodiments of the first aspect, a method for multi-access point (AP) collaboration is provided. The method includes: a station (STA) detects a trigger event, and the STA is served by an associated access point (AP); the STA analyzes the service requirements of the STA in response to the trigger event; and the STA sends a multi-AP collaboration parameter change message to the associated AP.

[0012] In some embodiments, the multi-AP collaboration parameter change message includes a multi-AP collaboration initialization request. In some embodiments, the message includes an update to the collaboration parameters of the current multi-AP collaboration. In some embodiments, the trigger event is triggered by an external factor associated with a change in the quality of service condition. In some embodiments, the message or request includes an analysis condition report. In some embodiments, the message or request is included as part of a physical layer protocol data unit (physical layer protocol data unit, PPDU). In some embodiments, the message or request is included as a specified frame. In some embodiments, the STA analyzes the service requirements of the STA in response to the trigger event, including: STA measuring and analyzing QoS metrics, QoS indicators including one or more of the following: (i) timeliness parameters; (ii) bandwidth parameters; (iii) reliability, stability and availability parameters. In some embodiments, the STA sends a multi-AP collaboration parameter change message to its associated AP, including: sending (i) timeliness parameters, such as acknowledgment (ACK) delay and jitter; (ii) bandwidth parameters, such as effective throughput and buffer size; (iii) reliability, stability, availability parameters, such as signal-to-interference-plus-noise ratio (SINR) changes, average bit error rate (BER), and average frame loss rate.

[0013] The second aspect of the present invention provides an AP-to-AP negotiation process for multi-AP collaboration. This aspect can be used alone, in combination with the first aspect, or can be used to improve other multi-AP collaboration methods and systems. In some embodiments, this process includes each AP maintaining a current database of neighboring APs based on previous multi-AP collaboration.

[0014] Therefore, in some embodiments, the method described above also includes: the associated AP receives a message related to multiple AP (multi-AP) collaboration from the STA; the associated AP broadcasts a message to an adjacent AP listed in a candidate AP table stored in a memory of the AP; the associated AP receives a response from the adjacent AP, the response including information related to the message of the STA; the associated AP selects an AP as a master AP for multi-AP collaboration based on the information in the response; the associated AP participates in the multi-AP collaboration according to the control message received from the master AP.

[0015] According to a second aspect of the present invention, a method for cooperation of multiple access points (APs) is provided, the method being performed by an AP (associated with a station (STA)). In this method, the AP receives a message related to cooperation of multiple APs (multi-APs) from the STA; the AP broadcasts a message to neighboring APs listed in a candidate AP table stored in a memory of the AP; the AP receives a response from the neighboring AP, the response including information related to the message of the STA; the AP selects an AP as a master AP for cooperation of multiple APs based on the information in the response; the AP participates in cooperation of multiple APs according to a control message received from the master AP. In some embodiments, the AP selects the neighboring AP as the master AP. In some embodiments, the AP updates its candidate AP table based on the information received in the response. In some embodiments, the information received in the response includes a cooperation score received from each neighboring AP according to a cooperation message of multiple APs (multi-APs) from the STA, and the method further includes the AP determining a cooperation score for itself. In some embodiments, the AP selects the AP as the master AP for cooperation of multiple APs based on the information in the response, including: selecting the AP with the highest cooperation score. In some embodiments, the cooperation score of each AP is calculated based on resource accessibility, resource availability, and resource quality.

[0016] In some embodiments, the AP selects itself as the master AP, and the method further includes: the master AP determines the participating APs in the multi-AP collaboration; including calculating and determining a cost-effective collaboration solution to satisfy the message. The method also includes: the master AP performs resource scheduling; the master AP sends a message to the participating APs according to the scheduling to control the multi-AP collaboration.

[0017] According to another aspect of the present invention, a device is provided, wherein the device includes a module for executing a method according to one or more aspects described herein. For example, on the other hand, a station (STA) device is provided, including: at least one processor; at least one wireless interface for communicating with at least one access point (AP); a machine-readable memory storing machine-readable instructions. When the machine-readable instructions are executed by the processor, the machine-readable instructions cause the STA: the station (STA) detects a trigger event, and the STA is served by an associated access point (AP); the STA analyzes the service requirements of the STA in response to the trigger event; and the STA sends a multi-AP cooperation parameter change message to the associated AP. In some embodiments, the multi-AP cooperation parameter change message includes a multi-AP cooperation initialization request. In some embodiments, the STA sends a multi-AP cooperation parameter change message to the associated AP, including: sending (i) timeliness parameters: acknowledgment (ACK) delay, jitter; (ii) bandwidth parameters: effective throughput, buffer size; (iii) reliability, stability and availability parameters: SINR change, average bit error rate and average frame loss rate.

[0018] Other aspects provide one or more devices, including: a memory for storing a program; a processor for executing the program stored in the memory, and when the program stored in the memory is executed, the processor is used to execute one or more aspects of the method described in this document.

[0019] According to another aspect, a computer-readable medium is provided, wherein the computer-readable medium stores a program code executed by a device, the program code being used to execute one or more methods described herein.

[0020] According to another aspect, a chip is provided. The chip includes a processor and a data interface. The processor reads instructions stored in a memory by using the data interface to execute one or more methods described herein.

[0021] Other aspects of the present invention provide apparatus and systems for implementing the methods disclosed herein. For example, wireless stations and access points may be configured with machine-readable memories including instructions that, when executed by processors of these devices, cause the devices to perform one or more methods disclosed herein.

[0022] Embodiments have been described above in conjunction with aspects of the present invention, and these embodiments may be implemented based on these aspects. It will be appreciated by those skilled in the art that embodiments may be implemented in conjunction with the aspects in which they are described, but may also be implemented together with other embodiments of this aspect. When the embodiments are mutually exclusive or contradictory, this will be apparent to those skilled in the art. Some embodiments may be described in conjunction with an aspect, but may also be applicable to other aspects, which will be apparent to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A multi-AP environment based on a basic service set (BSS) is schematically shown.

[0025] Figure 2 A user-centric approach, a BSS-free, user-centric, collaborative multi-AP environment is shown according to one embodiment.

[0026] Figure 3 is a system model showing an example of co-channel interference from overlapping basic service sets (OBSS).

[0027] Figure 4 A method implemented by a STA according to one embodiment is shown.

[0028] Figure 5 A method for initiating multi-AP cooperation according to a system including STAs and APs according to one embodiment is shown.

[0029] Figure 6 A multi-AP cooperative session of APs maintaining a candidate AP list according to one embodiment is shown.

[0030] Figure 7 An AP to AP negotiation method according to one embodiment is shown.

[0031] Figure 8 is a schematic diagram of a device that can perform any or all of the operations of the above methods and features described herein, either explicitly or implicitly, according to different embodiments of the present invention.

[0032] It should be noted that throughout the drawings, like features are identified by like reference numerals. DETAILED DESCRIPTION

[0033] The wireless communication system to which the embodiments of the present invention are applicable may be a wireless local area network (WLAN) device, referred to as a station (STA). Such a STA may be a mobile STA, but it is not required to be a mobile STA. For example, it is obvious that the embodiments of the present invention are applicable to a fixed STA or AP. The communication device may be a wireless communication device that supports other wireless protocols.

[0034] Multi-AP collaboration schemes have been discussed as a major candidate feature for adoption in the wireless LAN (WLAN) 802.11 standard. Achieving a certain degree of collaboration between neighboring APs can more efficiently use limited wireless resources, such as time, frequency, power, and space resources. Additionally, information sharing (i.e., user scheduling and channel quality information) between collaborative APs can improve co-channel interference that has become unacceptable in increasingly dense wireless networks. Therefore, in the case where STAs are located in overlapping basic service sets (BSSs), an embodiment allows multi-AP collaboration, which can transform interfering APs into servers.

[0035] In addition, as devices become more powerful and allow the execution of more and more complex applications, it is expected that rich application areas (e.g., multi-party cloud gaming and extended reality) will have increasingly diverse and multi-dimensional QoS requirements. Therefore, more efficient and intelligent resource allocation strategies are needed to meet user requirements.

[0036] Therefore, the embodiment provides a user-centric method that allows multiple APs to collaborate to allow potential service providers to improve performance gains. It should be noted that the term "user-centric" is used because many STAs are user devices, and one or more applications running on the STA are usually user applications. However, the term STA-centric method can also be used.

[0037] Specifically, this user-centric design can be achieved by flexibly adjusting the scope of multi-AP collaboration and context awareness. Different combinations of collaborative resource domains result in different solutions with different levels of balance in the implementation, as shown in Table I (which is summarized from C. Deng et al., "IEEE 802.11be Wi-Fi 7: New Challenges and Opportunities", IEEE Communications Surveys and Tutorials, Vol. 22, No. 4, pp. 2136-2166, Q4 2020). Table I: Overview and comparison of four multi-AP collaboration schemes

[0038] One advantage of the methods and systems disclosed herein comes from recognizing that a STA may be in a better position than an AP to evaluate at least some of these criteria. This may depend on factors internal to the STA (e.g., requirements of applications running on the STA) as well as external factors (e.g., conditions of the local STA that may be monitored and analyzed by the STA).

[0039] Different embodiments may provide STA customized QoS enhancements, which may depend on specific user (application) requirements and STA measurable conditions. For example, STAs may provide data relevant to making decisions related to interference mitigation; facilitating AP switching and load balancing; and efficient multi-dimensional resource scheduling and collaboration. Examples of each are now given:

[0040] One advantage of multi-AP collaboration is interference suppression. For example, edge users of overlapping basic service sets (OBSS) may be subject to co-channel interference. In some locations, co-channel interference is more severe, which is particularly problematic for some STAs that are semi-static or static in geographical location. Implementing multi-AP collaborative transmission can offset this negative impact. However, compared to APs, STAs are better positioned to measure co-channel interference.

[0041] Another benefit is that multi-AP collaboration can facilitate AP switching and load balancing. When a STA roams between multiple BSSs, its service request can be used to trigger multi-AP collaboration. This resource provision by multiple AP collaboration can facilitate fast association and switching, reducing service interruptions caused by increasing reconnection speed.

[0042] Another benefit is that multi-AP collaboration enables efficient multi-dimensional resource scheduling and orchestration. Taking collaborative OFDMA as an example, APs can synchronize their data transmission and allocate orthogonal time-frequency resources to multiple STAs. Therefore, the probability of conflict is greatly reduced compared to APs independently performing contention-based channel access processes. In addition, collaborative OFDMA can facilitate shortening the latency of short data packet data transmission because it allows efficient sharing and full occupancy of the working frequency band, otherwise the available resources will not be fully utilized.

[0043] Although multi-AP collaboration generally has the above advantages, the present invention provides additional advantages by providing a method and system for intelligently providing services to STAs with multi-dimensional resources in a user-centric manner. Therefore, the embodiment extends the scope of resource usage from single AP independent operation to multi-AP resource orchestration based on input provided by STA.

[0044] Figure 1Schematically illustrates an environment based on a basic service set (BSS). Each BSS20 is served by AP 30. Therefore, BSS20A is served by AP 30A, BSS20B is served by AP 30B, and BSS20C is served by AP 30C. As can be seen, STA 10A is within BSS20A, while STA 10B is within both BSS20A and BSS20B, and STA 10C is within both BSS20C and BSS20A. STA 10A within BSS20A will be served by AP 30A (or associated with AP 30A). STA 10B within BSS20A and BSS20B can be served by AP 30A or AP 30B. However, if STA 10B is served by AP 30A, it may receive co-channel interference from AP 30B.

[0045] Figure 2 A user-centric approach according to one embodiment is shown, which again eliminates the traditional disadvantaged BSS edge STAs. Rather than evaluating performance by individual BSSs, this embodiment uses a collaborative resource service cluster of spatially distributed neighboring APs specifically for each STA. To avoid cluttering the diagram, Figure 2 A single cluster 50 is shown centered around STA 10C, which includes APs 30A and 30C. However, it should be understood that each STA has its own user-centric cluster.

[0046] Figure 3 6 is a system model showing an example of co-channel interference from overlapping basic service sets (OBSS). The STA is currently associated with AP1, as shown by solid line 60. However, the STA is subject to co-channel interference from neighboring APs (i.e., AP2 and AP3), as shown by dashed lines 80 and 70, respectively.

[0047] Figure 4 A method implemented by a STA according to an embodiment is shown. The method includes the STA detecting a trigger event 100, and the STA is associated with an access point (AP). An example of such a trigger event is discussed below. The method also includes the STA analyzing (130) the service requirements of the STA in response to the trigger event. An example of such an analysis is discussed below. The method also includes: the STA sends (150) a multi-AP collaboration parameter change message to the associated AP. Such a message may include a multi-AP collaboration initialization request, and may also provide an update of parameters for the current multi-AP collaboration.

[0048] The trigger event 100 may depend on an internal factor (a factor internal to the STA) or an external factor (a factor external to the STA). In some embodiments, the trigger event 100 is triggered by an internal factor related to an application running on the STA. An example of an internal factor may be the launch (or request by) of a bandwidth-intensive or delay-sensitive application executed on the STA device. In some embodiments, the trigger event 100 is triggered by an external factor related to a change in quality of service conditions. For example, a sudden deterioration in channel quality or OBSS interference are examples of external factors. Table II: STA-specified predictive QoS information reporting

[0049] As shown, the mobility of the STA can be related to multi-AP collaboration because the mobility of the STA changes the QoS parameters. Therefore, the STA can monitor and analyze the mobility of the STA based on external factors (such as the conditions summarized in Table II). In some embodiments, the mobility of the STA can be detected as an internal factor (for example, detected by an accelerometer or GPS application running on the STA). It should be understood that it is not important to determine whether the trigger event 100 is based on internal factors or external factors. For example, mobility can be detected, reported, and can be used to influence the request of the STA, regardless of whether it is detected by internal factors or external factors.

[0050] Now, according to an embodiment, the STA will analyze (130) the service requirements of the STA in response to the triggering event. The STA monitors and analyzes the conditions of the air interface and link measurements. Then, the STA analyzes its own service requirements caused by the triggering event 100 and makes a decision whether to report to the associated AP (e.g., send a message 150).

[0051] Thus, embodiments relate to a QoS-related information reporting mechanism for evaluating and identifying STA resource requirements by a STA. In some embodiments, this includes configuring the STA to perform information processing and analysis locally in advance to (1) eliminate unnecessary and cumbersome reporting to the AP; and (2) avoid false alarms. Such QoS-related reporting can facilitate one or more APs to make decisions about resource allocation parameters, such as transmit power, bandwidth (RU), acceptable latency, queuing, and spatial beamforming design. In addition, in some embodiments, the STA's analysis can trigger the minimum requirements for multi-AP collaboration.

[0052] In some embodiments, in order to efficiently report, QoS indicators are measured and parameterized by: (i) timeliness, (ii) bandwidth (iii) reliability, stability and availability, all of which are calculated by each individual STA to reflect their own specific circumstances. In some embodiments, the STA measures and analyzes PHY and MAC layer indicators to identify and express the resource requirements of the STA, also to support differentiation of services with different requirements. As described above, the STA sending 150 multi-AP cooperation parameter change message to the associated AP may include one or more of the following: an initialization request for multi-AP cooperation; a report on parameters related to controlling and updating multi-AP cooperation. Therefore, in some embodiments, the STA sends a multi-AP cooperation parameter change message to the associated AP, which may include one or more of the following: (i) Timeliness parameters: (e.g., confirmation) ACK delay, jitter (e.g., delay jitter); (ii) Bandwidth parameters: (e.g. effective throughput, buffer size); (iii) Reliability, stability and availability parameters: (e.g., SINR variation, average bit error rate and average frame loss rate parameters).

[0053] The report includes but is not limited to the QoS information listed in the following Table III and Table IV. Table III: STA-QoS indicators and parameters:

[0054] In some embodiments, the STA can use a learning-based method to analyze historical data locally and achieve situational awareness through prediction. More specifically, in some embodiments, the STA performs analysis on the QoS information (e.g., deriving the probability distribution of the service arrival time interval) through a learning-based method (e.g., machine learning and deep reinforcement learning) to make the reporting more accurate and efficient. Therefore, in some embodiments, the STA can actively generate one or more reports of the analysis conditions. That is, the STA can actively send a request to the AP. Since it also takes time to establish multi-AP collaboration, the active / predictive request of the STA can help reduce the delay in providing information. For example, in some embodiments, if the STA detects (or predicts) that an emergency service needs to occur, the STA can then use a specified frame to report instead of using a physical layer protocol data unit (PPDU) to report, instead of waiting for the AP to trigger the sending of the PPDU. Different reporting methods are provided in Table V below. Table V: Reporting methods

[0055] The above embodiments discuss the method performed by the STA when requesting multi-AP cooperation and reporting multi-AP cooperation parameters.

[0056] According to an embodiment, a method performed by an AP is now discussed.

[0057] Figure 5 This method for initiating multi-AP collaboration according to a system including STAs and APs according to one embodiment is shown. Figure 5 In the embodiment, the STA responds to the triggering event 100 by evaluating the service requirements of the STA relative to possible multi-AP cooperation 120. If multi-AP cooperation is not requested, the AP and STA maintain the traditional independent mode (the STA is served by a single AP) 205.

[0058] After the AP receives and evaluates the request from STA 210, the AP will also decide whether to initiate multi-AP cooperation 220 or just follow the routine of independent transmission 205. If multi-AP cooperation is selected, the first step is to perform AP to AP negotiation 230, which is performed to determine the cooperation scope of participating APs.

[0059] During the negotiation 230, a master AP is elected to assume the roles of resource scheduler and coordinator. More details of the negotiation 230 will be referred to below. Figure 6 and Figure 7 for discussion. Next, after the AP to AP negotiation 230 is completed, the elected master AP will perform 240 multi-dimensional resource scheduling and notify all participating APs of their respective responsibilities. More specifically, multi-dimensional resource scheduling may include TXOPs in the time domain (e.g., via enhanced distributed channel access (EDCA)), spatial streams in the spatial domain (e.g., adjusted by multiple-input multiple-output (MIMO) technology), resource unit allocation in the frequency domain through orthogonal frequency division multiple access (OFDMA), and transmit power allocation in the power domain. The participating APs follow the received instructions and perform collaborative transmission 250.

[0060] According to the "specific situation", the final result of multi-AP collaboration can be divided into coordinated-OFDMA (Co-OFDMA), coordinated beamforming (Co-BF), coordinated spatial reuse (Co-SR) or joint transmission (JTX). Here, the specific situation can depend on two factors: (i) the details of the STA's request; (ii) the result of AP-to-AP negotiation. In other words, from the perspective of resource utilization, it is the STA's request and AP-to-AP negotiation that jointly determine which resource domains should be coordinated.

[0061] In some embodiments, for example, when a TXOP owner AP shares its TXOP with its neighboring APs, the TXOP owner AP may also coordinate available frequency, space, and / or power domain resources with these APs, which may result in four different scenarios:

[0062] In some embodiments, time domain and frequency domain resources are coordinated between participating APs, and multi-AP cooperation can be classified as Co-OFDMA. For example, Co-OFDMA with synchronized TXOP and fully occupied frequency band will reduce the probability of collision in the contention-based channel access process while shortening the short packet data transmission delay.

[0063] In some embodiments, the air and power domains are coordinated between APs, and multi-AP cooperation can be classified as Co-SR. When an OBSS signal is detected, the APs can cooperate with each other in TXOP to dynamically increase or decrease the transmit power level to mitigate interference and improve throughput. During cooperation, the size of the BSS is flexibly modified (and the execution of spatial multiplexing between cooperative APs can be achieved).

[0064] In some embodiments, only collaborative airspace resources are used, and multi-AP collaboration can be classified as Co-BF. Multi-antenna APs can use nulling control and beamforming techniques to further enhance spatial multiplexing capabilities. Compared with Co-OFDMA, Co-BF requires overlapping APs to organize their scheduling decisions and obtain accurate channel state information (CSI) from non-associated STAs to effectively perform radiation null placement.

[0065] In some embodiments, spatial resources, time domain resources, and frequency domain resources are all coordinated, and multi-AP cooperation can be called JTX in the most complex case. Non-co-located APs perform joint transmission and / or reception from (to) multiple STAs that reuse the same time / frequency resources. JTX is more likely to achieve the full potential of all performance gains. However, implementation complexity and high-speed backhaul connections need to be balanced when choosing JTX.

[0066] Therefore, collaboration in different resource domains will result in different multi-AP collaboration use cases (refer to the 4 categories listed in Table I above). Some embodiments may use a unified process design covering the scenarios described above.

[0067] Now discuss the method implemented by the AP according to the embodiment. In some embodiments, the goal of the AP to AP negotiation process is to maximize resource utilization while minimizing communication overhead between APs. In some embodiments, each AP maintains a candidate AP list that includes the latest information and attributes of its neighboring APs. Figure 6 An example of an embodiment involving three APs (AP1, AP2, and AP3) in AP negotiation is shown. Figure 6 The AP candidate list of AP1 (which includes neighboring APs, namely AP2 and AP3) is shown.

[0068] In some embodiments, each AP maintains a candidate AP list, which is constructed and updated through information exchange between APs and past collaborative experience. In some embodiments, the candidate AP list of each AP can be maintained and updated by a collaborative learning tool. For example, the collaborative learning tool can be configured as a machine learning tool or other artificial intelligence learning tool that is easy to understand. Table VI shows an example of information used to establish a candidate AP list, including available resources, current workloads, and their operating details. Table VI: Information and parameters used in AP-to-AP negotiation

[0069] According to an embodiment, after receiving the request from the STA, the original AP associated with the STA broadcasts the resource requirements of the STA to all APs in its candidate AP list. Therefore, all APs can calculate the cooperation score relative to the request from the STA.

[0070] According to an embodiment, the collaboration score may be measured by three metrics: resource accessibility, resource availability, and resource quality. STA's AP collaboration score = w1 · {resource accessibility} + w2 · {resource availability} + w3 · {resource quality} Where w is the weight factor in this exemplary model.

[0071] More specifically, these three indicators can be flexibly defined and adjusted in practice. Each AP evaluates its own resource provisioning capabilities for STA's requests by performing a review on the necessary probes (e.g., by measuring the STA's CSI). Here we can define resource availability, resource accessibility, and resource quality, where: Resource availability: Evaluate the availability of bandwidth (or RU), TXOP, transmit power budget, and spatial streams on different AP sides. Resource accessibility: evaluates (i) the distances between the requesting STA and different APs; and (ii) the probability of acceptance of the request of the STA served by different APs. Resource quality: Evaluate the link quality between the requesting STA and different APs, which can be judged by SINR, RSRP, and RSSI.

[0072] For example, in cooperative OFDMA, an AP that is a TXOP owner obtains a higher score in the “Resource Availability” section, and an AP that has a shorter geographical distance to a requesting STA has the potential to obtain a higher score in the “Resource Accessibility” section.

[0073] It should be noted that during a multi-AP cooperation session, the APs share the same method (or indicator) for calculating the cooperation score to avoid confusion in the process of electing the master AP.

[0074] The collaboration score can be used to evaluate / verify the qualifications, suitability, and implementation complexity of each AP to participate in multi-AP collaboration. In some embodiments, the original AP collects and compares all scores. The AP with the highest score will be elected as the master AP.

[0075] according to Figure 6 , it can be considered that AP3 obtains the highest collaboration score and thus becomes the main AP.

[0076] Figure 6 An example of a message between an AP and a STA for establishing a multi-AP cooperative session according to an embodiment is shown. Figure 7 The corresponding method steps for establishing a multi-AP collaborative session according to one embodiment are shown. The process is initialized by a request 150 from the STA to its currently associated AP1. Then, AP1 "evaluates" this request to determine whether to initiate multi-AP collaboration. This evaluation performed by the AP mainly checks the resource allocation parameters and priority of the request about the STA. If the decision is "yes", AP1 initiates Figure 7The method shown. Therefore, the AP (AP1) currently associated with the STA performs (710) multicast transmission 305A, 305B to all APs included in its candidate AP list. It should be noted that although a multicast message is shown, it should be understood that a broadcast message or a unicast message to each of AP2 and AP3 can be used. Such messages 305A, B include information requested from the STA. In some embodiments, the multicast message may include AP1's candidate list (after being updated with information from the STA request message). After the neighboring APs (i.e., AP2 and AP3) receive the multicast message from AP1, the neighboring APs will calculate (720) the cooperation score regarding the STA's request based on the information in the multicast message and the AP's own candidate list. The other APs (each of AP2 and AP3) respond to AP1 with their corresponding calculated cooperation scores through response messages 315A, 315B 730. AP1 then collects and compares the cooperation scores, and then notifies the highest score owner to become the master AP 740. As shown Figure 6 As shown, AP1 determines that AP3 has achieved the highest score (i.e., AP3) as the elected master AP, and sends a message 330 to AP3 to instruct it to act as the master AP. In some embodiments, AP1 may notify other neighboring APs (e.g., AP2) of the election. In some embodiments, AP1 may also send a message to the neighboring APs, the message including information for updating its candidate list, such as the information in Table V. In addition, in some embodiments, the AP responses 315A, 315B may include information for updating its candidate list, such as the information in Table V.

[0077] The elected master AP calculates and determines the most cost-effective collaboration scheme, and then performs resource scheduling according to the STA's request 750. Based on the resource scheduling results, the master AP sends instructions to all participating APs to notify their corresponding "responsibilities" 760. The STA's request sets the minimum requirements for multi-AP collaboration. In some embodiments, as long as the STA's request is met, the master AP will not over-provide resources or services. In other words, the master AP will select the most cost-effective collaboration scheme (i.e., in terms of implementation complexity or energy efficiency).

[0078] Finally, multi-AP cooperation begins (770). Data packets will be transmitted according to the instructions of the master AP using one of the multi-AP cooperation schemes discussed above (ie, Co-OFDMA, Co-BF, Co-SR, and JTX).

[0079] In some embodiments, each multi-AP collaboration session between APs is used to review and update the candidate AP list if necessary due to any observed parameter changes. In this way, the embodiment provides a history of multi-AP collaboration, which provides the latest candidate list for each AP. This can be used for subsequent multi-AP collaboration.

[0080] When processing multiple requesting STAs simultaneously, the proposed scheme is extended in the following manner: First, in the case where multiple requesting STAs are from the same BSS, the associated AP pre-evaluates and processes the request 210 of each STA (e.g., the AP may prioritize these requests according to their QoS specifications), such as Figure 5 As shown, it is then determined whether each STA needs to initiate multi-AP cooperation 220. Otherwise, the STA will return to independent transmission mode. After this step, during the AP to AP negotiation process, the associated AP will request cooperation with other neighboring APs by aggregating the requests of multiple STAs as a whole. Therefore, it can guarantee most of the performance gains and avoid confusion of different configurations / settings of multi-AP cooperation.

[0081] It is understandable that in an actual Wi-Fi network, a scenario where there are multiple requesting STAs is usually more common than a scenario where there is a single requesting STA.

[0082] In the case where multiple requesting STAs are from different BSSs and each independent AP may send a request message for cooperation, the election of a master AP may be considered. In some embodiments, the election of the master AP and the resource scheduling performed may follow the majority principle. Specifically, the APs notify each other of the request and calculate the corresponding cooperation score, and the AP with the highest cooperation score is elected as the master AP. The identification of the master AP is intended to ensure the majority interests of all STAs located in different BSSs.

[0083] When processing multiple requesting STAs simultaneously, the STA's request will be reflected in the AP's current workload, affecting the calculation of its cooperation score. The end result is that multiple coordinated APs can simultaneously serve STA clusters with non-conflicting requirements. In other words, the combination of candidate AP lists and cooperation scores can help efficiently resolve and manage multiple requesting STAs.

[0084] In summary, the purpose of AP-to-AP negotiation is to enhance mutual understanding between neighboring APs, optimize the load balancing process, and intelligently use all available resources.

[0085] Some embodiments provide a wireless system including a first access point (AP) and a second access point. In such a system, the first access point is used to: receive a message related to multiple AP (multi-AP) collaboration from a station (STA); broadcast information from the message to neighboring APs listed in a table of candidate APs stored in a memory of the first AP, the neighboring APs including a second AP; receive a response from the neighboring AP, the response including information related to the message of the STA; based on the information in the response, send a control message to the second AP to act as a master AP for the multi-AP collaboration. In such a system, the second access point is used to: receive a control message from the first AP; calculate and determine a cost-effective collaboration scheme to satisfy the control message; perform resource scheduling to support the multi-AP collaboration of the STA; send a message to the participating APs according to the schedule to control the multi-AP collaboration.

[0086] Figure 8 1 is a schematic diagram of a device 1000 that can perform any or all operations of the above methods and features described explicitly or implicitly herein according to different embodiments of the present invention. For example, a computer equipped with a network function can be configured as the device 1000. As can be understood by those skilled in the art, the device 1000 can represent one or more entities described herein, such as an AP, a STA, etc.

[0087] As shown, device 1000 may include a processor 1010 (e.g., a central processing unit (CPU) or a special processor, such as a graphics processing unit (GPU), or other such processor unit), a memory 1020, a non-transitory mass storage 1030, an input / output interface 1040, a network interface 1050, and a transceiver 1060, all of which are communicatively coupled via a bidirectional bus 1070. According to certain embodiments, any or all of the elements shown may be used, or only a subset of the elements shown may be used. In addition, device 1000 may include multiple instances of certain elements, such as multiple processors, multiple memories, or multiple transceivers. In addition, elements of a hardware device may be directly coupled to other elements without a bidirectional bus. In addition to or in place of a processor and memory, other electronic components such as integrated circuits may be used to perform the desired logic operations.

[0088] The memory 1020 may include any type of non-transitory memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or any combination thereof. The mass storage element 1030 may include any type of non-transitory storage device, such as a solid-state disk, a hard disk drive, a disk drive, an optical drive, a USB drive, or any computer program product for storing data and machine executable program code. According to some embodiments, the memory 1020 or the mass storage 1030 may record therein statements and instructions executable by the processor 1010 for performing any of the above-described method operations.

[0089] Embodiments of the present invention may be implemented using electronic hardware, software, or a combination thereof. In some embodiments, the present invention is implemented by one or more computer processors executing program instructions stored in a memory. In some embodiments, the present invention is implemented in part or in whole in hardware, for example, using one or more field programmable gate arrays (FPGAs) or application specific integrated circuits (ASICs) to quickly perform processing operations.

[0090] It should be understood that although specific embodiments of the technology are described herein for illustrative purposes, various modifications may be made without departing from the scope of the technology. Therefore, the specification and drawings are simply regarded as an illustration of the invention as defined by the appended claims, and are contemplated to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the invention. Specifically, providing a computer program product, a program element, or a program storage device such as a magnetic or optical wire, tape or optical disk for storing machine-readable signals for controlling the operation of a computer according to the method of the present technology, and / or for constructing some or all of its components according to the system of the present technology is within the scope of the present technology.

[0091] The actions associated with the methods described herein may be implemented as coded instructions in a computer program product. In other words, a computer program product is a computer readable medium on which software codes are recorded to perform the methods when the computer program product is loaded into a memory and executed on a microprocessor of a wireless communication device.

[0092] In addition, each operation of the method can be performed on any computing device (e.g., personal computer, server, PDA, etc.), and can be performed according to one or more program elements, modules or objects or a part of one or more program elements, modules or objects generated from any programming language (e.g., C++, Java, etc.). In addition, each operation or a file or object that implements each operation, etc. can be performed by dedicated hardware or a circuit module designed for this purpose.

[0093] Through the description of the above embodiments, the present invention can be implemented only by hardware, or by software and necessary general hardware platforms. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product. The software product can be stored in a non-volatile or non-transient storage medium, and the non-volatile or non-transient storage medium can be a compact disk read-only memory (CD-ROM), a USB flash drive, or a removable hard disk. The software product includes many instructions that enable a computer device (a personal computer, a server, or a network device) to perform the method provided in the embodiment of the present invention. For example, this execution may correspond to a simulation of a logical operation as described herein. According to an embodiment of the present invention, the software product may additionally or alternatively include a plurality of instructions that enable a computer device to perform operations to configure or program a digital logic device.

[0094] Although the present invention has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations are possible without departing from the scope of the invention. Accordingly, the specification and drawings are to be regarded simply as illustrations of the invention as defined by the appended claims, and are intended to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the invention.

Claims

1. A method for controlling cooperation of multiple access points (APs), characterized in that: include: A station (STA) detects a triggering event, the STA being served by an associated access point (AP); The STA analyzes, in response to the triggering event, a service requirement of the STA; The STA sends a multi-AP cooperation parameter change message to the associated AP.

2. The method according to claim 1, characterized in that: The multi-AP cooperation parameter change message includes a multi-AP cooperation initialization request.

3. The method according to claim 1 or 2, characterized in that: The trigger event is triggered by an internal factor related to the application running on the STA.

4. The method according to claim 1 or 2, characterized in that: The trigger event is triggered by an external factor related to a change in a service quality condition.

5. The method according to any one of claims 1 to 4, characterized in that The request includes an analysis condition report.

6. The method according to any one of claims 1 to 5, characterized in that One or more of the message and the request are included as part of a physical layer protocol data unit (PPDU).

7. The method according to any one of claims 1 to 6, characterized in that One or more of the message and the request are included in a designated frame.

8. The method according to any one of claims 1 to 7, characterized in that The STA analyzing the service requirements of the STA in response to the triggering event includes: the STA measuring and analyzing a QoS indicator, where the QoS indicator includes one or more of the following: (i) Timeliness parameters; (ii) bandwidth parameters; (iii) Reliability, stability and availability parameters.

9. The method according to claim 8, characterized in that The STA sending a multi-AP cooperation parameter change message to the associated AP includes: sending one or more of the following: (i) Timeliness parameters: acknowledgment (ACK) delay and jitter; (ii) Bandwidth parameters: effective throughput, buffer size; (iii) Reliability, stability and availability parameters: signal-to-interference-plus-noise ratio (SINR) variation, average bit error rate (BER) and average frame loss rate.

10. The method according to any one of claims 1 to 9, characterized in that Also includes: The associated AP receives a message related to multiple AP (multi-AP) collaboration from the STA; The associated AP broadcasts a message to neighboring APs listed in the candidate AP table stored in the memory of the AP; The associated AP receives a response from the neighboring AP, the response including information related to the message of the STA; The associated AP selects an AP as a master AP for the multi-AP collaboration based on the information in the response; The associated AP participates in the multi-AP collaboration according to a control message received from the master AP.

11. A method for multiple access points (APs) collaboration, characterized in that: The method is performed by an AP associated with a station (STA), and the method includes: The AP receives a message related to multiple AP (multi-AP) collaboration from the STA; The AP broadcasts a message to neighboring APs listed in a candidate AP table stored in a memory of the AP; The AP receives a response from the neighboring AP, the response including information related to the message of the STA; The AP selects a master AP for the multi-AP collaboration based on the information in the response; The AP participates in the multi-AP collaboration according to a control message received from the master AP.

12. The method according to claim 11, characterized in that The AP selects one of the neighboring APs as the master AP.

13. The method according to claim 12, characterized in that The AP updates the candidate AP list based on the information received in the response.

14. The method according to claim 13, characterized in that The response from each of the neighboring APs includes a cooperation score for the particular neighboring AP, and the method further includes the AP determining its own cooperation score.

15. The method according to claim 14, characterized in that The AP selects the master AP based on the cooperation score, wherein the master AP has the highest cooperation score.

16. The method according to claim 15, characterized in that The cooperation score of each AP is calculated based on one or more of resource accessibility, resource availability, and resource quality.

17. The method according to claim 15 or 16, characterized in that The AP selects itself as the master AP, and the method further includes: The master AP determines the participating APs in the multi-AP collaboration, wherein the determination includes calculating and determining a cost-effective collaboration solution to satisfy the message; The master AP performs resource scheduling; The master AP sends a message to the participating APs according to the scheduling to control the multi-AP collaboration.

18. A station (STA) device, characterized in that: include: at least one processor; at least one wireless interface, configured to communicate with at least one access point (AP); a machine-readable memory storing machine-readable instructions that, when executed by the at least one processor, cause the STA to: Detecting a triggering event, the STA is served by an associated access point (AP); analyzing a service requirement of the STA in response to the triggering event; Send a multi-AP cooperation parameter change message to the associated AP.

19. The station according to claim 18, characterized in that The multi-AP cooperation parameter change message includes a multi-AP cooperation initialization request.

20. The station according to claim 18 or 19, characterized in that Sending a multi-AP collaboration parameter change message to the associated AP includes: (i) sending timeliness parameters, wherein the timeliness parameters include one or more of acknowledgment (ACK) delay and jitter; (ii) sending bandwidth parameters, the bandwidth parameters comprising one or more of effective throughput and buffer size; (iii) sending reliability, stability and availability parameters, wherein the reliability, stability and availability parameters include one or more of signal-to-interference-plus-noise ratio (SINR) variation, average bit error rate (BER) and average frame loss rate.

Images