Enhanced mechanisms for fine time measurement

Abstract

In implementations of the disclosure, a method for an enhanced mechanism for fine time measurement is provided. The method includes detecting, by an access point (AP) multi-link device (MLD), a set of parameters for each of a plurality of links between the AP MLD and a set of station MLDs. The AP MLD can then determine a score for each of the plurality of links using the set of parameters. The plurality of scores for the plurality of links can be used to select a set of links from the plurality of links for transmission of a plurality of FTM frames. The AP MLD also determines a number of FTM frames to transmit on one of the set of links. The AP MLD then transmits the number of FTM frames to the set of station MLDs via the one of the set of links.

Description

Background Technology

[0001] Fine Time Measurement (FTM), also known as Wi-Fi Round Trip Time (RTT), aims to estimate the distance between an initiating and responding station. For example, it calculates the round-trip time difference between the initiating and responding stations to determine the distance. FTM is an upgrade or enhancement technique compared to location features based on Received Signal Strength Indication (RSSI).

[0002] Multilink Operation (MLO) is a key Media Access Control (MAC) feature introduced in Wi-Fi 7. It enables devices to exchange frames across multiple links. MLO allows a Site Multilink Device (MLD) to discover, authenticate, associate, and establish multiple links with an Access Point (AP) MLD. Each link enables channel access and frame exchange between the Site MLD and the AP MLD based on the supported capabilities exchanged during association. Attached Figure Description

[0003] Embodiments of this disclosure can be understood from the following detailed description when read in conjunction with the accompanying drawings. According to standard industry practice, the various features are not drawn to scale. In practice, the dimensions of the various features can be arbitrarily increased or decreased for clarity of explanation. Some examples of this disclosure are described with reference to the following drawings.

[0004] Figure 1 A block diagram illustrating an example environment in which a reference embodiment of the present disclosure may be implemented;

[0005] Figure 2 The illustration shows an example of using a link to transmit FTM frames according to an embodiment of the present disclosure;

[0006] Figure 3 The illustration shows an example of using multiple links to transmit FTM frames according to an embodiment of the present disclosure;

[0007] Figure 4 An example of transmitting FTM frames on two links according to an embodiment of the present disclosure is illustrated;

[0008] Figure 5 An example of transmitting FTM frames during a restricted target wake-up time (R-TWT) service period (SP) according to an embodiment of the present disclosure is illustrated;

[0009] Figure 6 The illustration shows a flowchart of determining the total measurement error and the total number of targets for an FTM frame according to an embodiment of the present disclosure;

[0010] Figure 7 A flowchart illustrating an example method for controlling an AP MLD according to an embodiment of the present disclosure is shown; and

[0011] Figure 8 An example access point multilink device according to an embodiment of the present disclosure is illustrated. Detailed Implementation

[0012] As discussed above, FTM is used to estimate the distance between the initiating and responding stations. Because the FTM measurement process is time-sensitive, the unicast frames used for FTM need to be transmitted multiple times between the initiating and responding stations within a short inter-frame interval (SIFS), a process known as FTM burst. If the initiating station has multiple neighbors, it needs to communicate with each neighbor one after another. In this case, a problem arises because the current operating frequency band / home channel band will be occupied during the FTM process, introducing a self-service pause and increasing time delay.

[0013] Furthermore, achieving accurate FTM results requires multiple factors, such as high bandwidth, the latest High Efficiency (HE) / Enhanced High Throughput (EHT) standards, and low interference. Another issue is that while multiple FTM bursts can contribute to improved accuracy, they can also lead to periodic interruptions of BSS service.

[0014] Furthermore, Multi-Link Operation (MLO) is a key Media Access Control (MAC) feature introduced in WiFi-7, enabling non-AP MLDs to establish multiple links with AP MLDs. Each of these links allows channel access and frame exchange between the non-AP MLD and the AP MLD. However, there are no available guidelines or widely adopted techniques to leverage the MLO feature with FTM. Moreover, the two issues mentioned above become even more complex in the MLD case.

[0015] Therefore, embodiments of this disclosure propose a solution for enhancing FTM in Wi-Fi 7 MLD. According to embodiments of this disclosure, the AP MLD can detect a set of parameters for each of a plurality of links between the AP MLD and a set of site MLDs. The AP MLD can then use this set of parameters to determine a score for each of the plurality of links. The multiple scores of the plurality of links are used to select a set of links from the plurality of links for transmitting a plurality of FTM frames. Next, the AP MLD can also determine the number of FTM frames to be transmitted on one of the links in the set of links. The AP MLD then transmits that number of FTM frames to the set of site MLDs via one of the links in the set of links.

[0016] Therefore, the AP MLD can use the scores of multiple links to determine a link set from multiple links, and allocate multiple FTM frames on the determined link set. Thus, one link is used to transmit FTM frames, while other links among the multiple links can be used to transmit traffic between the AP MLD and the site's MLD set. Therefore, this method avoids time delays and pauses in traffic between the AP and the site's MLD set during the FTM measurement process.

[0017] Other advantages of embodiments of this disclosure will be described with reference to the following reference embodiments. Figures 1 to 8 The basic principles of this disclosure and several reference embodiments are illustrated.

[0018] Figure 1 A block diagram is shown of an example environment in which reference embodiments of the present disclosure may be implemented. Figure 1 In example environment 100, AP MLD 104 communicates with the set of sites MLD 102 via multiple links (e.g., link 106-1, ..., link 106-N, where N is an integer).

[0019] In one example, multiple links can be two links. For example, one link involves 2.4 GHz, while the other link involves 5 GHz. In another example, multiple links can be three links. For example, the first link involves 2.4 GHz, the second link involves 5 GHz, and the third link involves 6 GHz. The above embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0020] The MLD 102 set includes MLD 102-1, MLD 102-2, ..., and MLD 102-M, where M is an integer. Each of MLD 102-1, MLD 102-2, ..., and MLD 102-M can communicate with AP MLD 104 via a portion of or all of multiple links. For example, there are three links between AP MLD 104 and this set of MLD 102 sites. The 2.4GHz, 5GHz, and 6GHz frequency bands are used. Site MLD 102-1 can communicate with AP MLD 104 via two links (e.g., the 2.4GHz and 5GHz links). Site MLD 102-2 can communicate with AP MLD 104 via three links.

[0021] In embodiments of this disclosure, for each of the multiple links, AP MLD 104 can detect a set of parameters. For example, for link 106-1, AP MLD 104 can detect link parameter set 108-1; and for link 106-N, AP MLD 104 can detect link parameter set 108-N. Furthermore, the detection parameters for each link are the same.

[0022] For example, AP MLD 104 can detect the number of sites connected to AP MLD 104 on each of multiple links. Furthermore, AP MLD 104 can detect the channel utilization of each of the multiple links, which refers to the proportion of time a communication channel is actually used within a given time period. Additionally, AP MLD 104 can detect service priority, site type, bandwidth, noise floor, Received Signal Strength Indicator (RSSI), and / or feedback from previous FTM results. Therefore, the parameter set for each link can include at least one of the following: number of sites, channel utilization, service priority, site type, bandwidth, noise floor, RSSI, and feedback from previous FTM results, to calculate a link score. The above description is for illustrative purposes only and is not intended to limit the scope of this disclosure. This parameter set can include any suitable parameters.

[0023] After obtaining the parameter set for each of multiple links, the AP MLD 104 can use this parameter set to calculate a link score to evaluate link quality. For example, parameter set 108-1 for link 106-1 can be used to calculate the score 110-1 for link 106-1; parameter set 108-N for link 106-N can be used to calculate the score 110-N for link 106-N. In one example, the AP MLD 104 uses the number of sites, channel utilization, bandwidth, noise floor, RSSI, and feedback from previous FTM results on link 106-1 to calculate the score for link 106-1.

[0024] The AP can then determine a set of links from multiple links based on their scores. In one example, AP MLD 104 can select one link from multiple links based on its score. The selected link is used to transmit multiple FTM frames between AP MLD 104 and the site MLD set 102. In another example, AP MLD 104 can select multiple links with scores greater than a threshold score. The selected multiple links are used to transmit multiple FTM frames between AP MLD 104 and the site MLD set 102. Alternatively or additionally, multiple links with scores are selected or determined to transmit multiple FTM frames between AP MLD 104 and the site MLD set 102.

[0025] In addition, the AP MLD 104 also needs to determine the number of FTM frames 112 to be transmitted on one of the links in the link set. For example, if link 106-1 is selected to transmit FTM frames, the AP MLD 104 also determines the number of FTM frames to be transmitted on link 106-1. The AP MLD 104 can determine the number of FTM frames to be transmitted on a link based on the link's score. For example, if the scores of multiple links are used to select only one link to transmit FTM frames, the number of FTM frames transmitted on the selected link is the total number of FTM frames. If all of the multiple links are used to transmit FTM frames, the score is used to allocate FTM frames across the multiple links. For example, if a link has a higher score, more FTM frames are allocated to that link; and if a link has a lower score, fewer FTM frames are allocated to that link.

[0026] The AP MLD 104 then uses the determined set of links to transmit multiple FTM frames. By transmitting FTM frames, the AP MLD 104 can perform FTM measurements. These FTM measurements can be used to estimate the distance between the AP MLD 104 and the target site receiving the FTM frames. By performing several FTM measurements, the distance can be calculated accurately.

[0027] Figure 2 Example 200 is illustrated using a single link to transmit FTM frames according to an embodiment of this disclosure. In example 200, a set of MLD sites 202 communicates with an AP MLD 204 via multiple links including link 206-1, link 206-2, ..., and link 106-N. For the multiple links, the AP MLD 204 can obtain link parameters for each of the multiple links. The AP MLD 204 then uses the obtained link parameters to calculate a score for each link, thereby obtaining multiple scores for the multiple links.

[0028] In some implementations, AP MLD 204 can use an algorithm to calculate a score for each of multiple links. In this algorithm, the score for a link is calculated using the number of sites, site type (MLD or non-MLD), number of supported frequency bands, service priority, and channel utilization. Therefore, multiple scores for multiple links are obtained according to this algorithm. A target score 208 is then selected from the multiple scores. For example, the target score is the highest score. Therefore, the optimal link with the highest score is selected from the multiple links to transmit all FTM frames 210 between AP MLD 204 and the site MLD set 202 for FTM measurements, such as performing an FTM scan on a specific neighboring device with FTM capability.

[0029] Alternatively, a configuration knob can be introduced as "MLD FTM auto". When this knob is enabled and FTM scanning is enabled on multiple radios, AP MLD 204 will select the best link among multiple links for FTM scanning, while avoiding impacting site services on other links between AP MLD 204 and the site's MLD set 202.

[0030] In some implementations, the AP MLD 204 can use the following equation (1) to calculate a score for each of the multiple links:

[0031] Δ weight =f(channel utility,bandwidth,NF,RSSI,Feedback link-i ,...) (1)

[0033] Where Δ weight This represents the link score or standard; f() represents the function used to calculate the score; NF represents the noise floor; RSSI represents the received signal strength indicator; and Feedback... link-i This represents the FTM result feedback for the i-th link. Therefore, for multiple links, AP MLD 204 can obtain multiple scores. In one example, AP MLD 204 determines the highest score from the multiple scores as the target score 208 and selects the link with the highest score from the multiple links. The selected link is then used to transmit all FTM frames 210 between AP MLD 204 and the MLD set of that site. In another example, AP MLD 204 can determine the lowest score from the multiple scores as the target score and select the link with the lowest score from the multiple links. Therefore, the link with the lowest score is used to transmit all FTM frames 210.

[0034] As described above, the target link, or the selected link, is used to transmit all FTM frames 210 between AP MLD 204 and the site MLD set 202. Because only one link is used to transmit FTM frames, the other links among the multiple links will not be used to transmit FTM frames. In this case, the other links are still used to serve the traffic between AP MLD 204 and the site MLD set 202. In this situation, when one radio is performing an FTM scan, AP MLD 204 will prohibit other radios from performing FTM scans, thus allowing the site MLD to maintain data traffic with minimal interruption.

[0035] As mentioned above, Figure 2 An example of transmitting FTM frames using a single link is shown. (Reference) Figure 3Another example of transmitting FTM frames is presented. Figure 3 Example 300 is shown, illustrating the use of multiple links to transmit FTM frames according to an embodiment of this disclosure.

[0036] In Example 300, AP MLD 304 and site MLD set 302 communicate with each other via multiple links (including links 306-1, 306-2, ..., 306-N). AP MLD 304 can calculate multiple scores for multiple links, and each link has a corresponding score. See reference... Figure 2 The scores are calculated based on the information described in the documentation. For example, AP MLD 304 can determine a score of 308-1 for link 306-1, a score of 308-2 for link 306-2, ..., and a score of 308-N for link 306-N. AP MLD 304 can then use these scores to determine how many FTM frames need to be transmitted on each of the multiple links. For example, AP MLD 304 determines FTM frame 310-1 to be transmitted on link 306-1 based on score 308-1. AP MLD 304 determines FTM frame 310-2 to be transmitted on link 306-2 based on score 308-2, and FTM frame 310-N to be transmitted on link 306-N based on score 308-N.

[0037] Furthermore, AP MLD 304 can obtain the total number of multiple FTM frames between AP MLD 304 and the site's MLD set 302. The total number of multiple FTM frames equals the total number of bursts. The total number of bursts is calculated using the following equation (2):

[0038] N total burst =N clients ·M each client burst number (2)

[0039] Where N clients This represents the total number of stations, and M... each client burst number This indicates the number of FTM exchanges required at each station.

[0040] After determining the total number of FTM frames, the AP MLD 304 can also distribute multiple FTM frames on multiple links based on multiple scores.

[0041] For example, the total number of bursts can also be calculated using the following equation (3):

[0042]

[0043] Where Δ weight-i Indicates linki The score, where n represents the number of links; link i Let represent the i-th link. In equation (3) above, 'link'... i The value can be 1. Therefore, the number of FTM frames for one unit of score (Burst) min It can be calculated using the following equation (4):

[0044]

[0045] In determining Burst min Next, you need to link i The FTM frames transmitted can be obtained by using Burst min Multiply by Δ weight-i To calculate.

[0046] In some implementations, the AP MLD 304 can calculate a ratio with respect to multiple scores. The AP MLD 304 then uses the ratio term as the corresponding score. Therefore, each of the multiple links has a corresponding ratio term. The AP MLD 304 can then determine the number of FTM frames to be transmitted on each of the link sets based on the total number and the ratio. For example, if the number of site MLD sets is 8 and the burst size is 8, then N total burst The value will be 8. Assume there are three MLD links, and after calculation, the Δ for the three links... weight The ratio is 4:3:1, then Burst min The number will be 8. Then, the final number of FTM bursts allocated to each link will be 32 for link-1, 24 for link-2, and 8 for link-3.

[0047] As mentioned above, multiple TWT frames can be distributed across multiple links. In this case, multiple links can be used to transmit multiple FTM frames. TWT characteristics (individual / broadcast / restricted TWT) can be utilized to protect the FTM process, making the FTM bursts more accurate and efficient for each MLD link. Figure 4 An example 400 of transmitting FTM frames over two links according to an embodiment of the present disclosure is illustrated. In example 400, R-TWT is used as an example. AP MLD 402 has two virtual access points (VAPs), namely VAP 1 and VAP2, and site MLD 404 has two stations, namely STA 1 and STA 2. There are two links (link 1 and link 2) between AP MLD 402 and site MLD 404.

[0048] Link 1 is used to transmit services between VAP 1 and STA 1, while Link 2 is used to transmit services between VAP 2 and STA 2. AP MLD 402 and site MLD 404 will establish an R-TWT session between Link-1 and Link-2. For example, there are two service periods (SPs) for R-TWT-1 on Link 1, namely SP 406 and SP 408. SP 406 and SP 408 are used to transmit FTW frames allocated to Link 1. On Link 2, there are two SPs for R-TWT-2, namely SP 410 and SP 412. SP 410 and SP 412 are used to transmit FTW frames allocated to Link 2. Figure 4 As shown, this session is staggered in time. For example, SP 406 on Link 1 is used in a different time period than SP 410 and SP 412 on Link 2. SP 408 on Link 1 is used in a different time period than SP 410 and SP 412 on Link 2. Meanwhile, SP 410 and SP 412 on Link 2 are also used at different times than SP 406 and SP 408 on Link 1. This method ensures that an MLD link can serve the client while FTM frame switching is performed on another link.

[0049] Figure 5 The illustrations show some examples of transmitting FTM frames in an R-TWT SP according to embodiments of the present disclosure. In example 500, during the R-TWT scheduling process, the AP MLD sends beacon 502 to STA 1 and STA 2. The beacon includes at least two information elements (IEs): an R-TWT IE 504 and a silence IE 506. The R-TWT IE 504 includes the start time of the R-TWT SP 510. The silence IE includes the start time of the silence interval 508. The start time of the R-TWT SP 510 is the same as the start time of the silence interval 508. Therefore, the silence IE is used to contend with the R-TWT SP start time, a feature that makes every effort to ensure that the FTM exchanged frames are free from other interference and to make the results more accurate.

[0050] Next, AP MLD transmits a request to STA 1 to send a Transmit (RTS) frame 512. The RTS frame contains information such as the time required for data transmission. After STA 1 receives the RTS frame 512, it sends a Clear to Transmit (CTS) frame 514 to AP MLD. Upon receiving the CTS frame 514, AP MLD determines it can begin transmitting data. Then, AP MLD transmits an FTM frame 516 to STA 1 on link 1. STA 1 accepts the FTM frame 516, generates an Acknowledgment (ACK) frame 518 for the FTM frame 516, and sends the ACK frame 518 to AP MLD. AP MLD can then continue transmitting another FTM frame 520 to STA 1, and after STA 1 receives the FTM frame 520, STA 1 continues sending an ACK frame 522 to AP MLD. During this process, communication between AP MLD and STA 2 on the same link is prohibited. Figure 5 The illustration shows the transmission of two FTM frames to STA 1 within an R-TWT SP 1. This is an example used to illustrate the present disclosure and not to limit it. In some implementations, multiple FTM frames or one FTM frame may be transmitted within an R-TWT SP. Furthermore, the same applies to standalone / broadcast TWTs.

[0051] After transmitting FTM frames on multiple links, FTM measurements are performed collaboratively across these links to reduce the total measurement error, thereby improving the overall accuracy. In this case, small bursts N (measurement counts) are determined when the total error E remains below a certain threshold. (Refer to...) Figure 6 Describe the process. Figure 6 The illustration shows a flowchart of determining the total measurement error and the total number of targets for an FTM frame according to an embodiment of the present disclosure.

[0052] In method 600, at block 602, AP MLD 104 determines the measurement error of multiple FTM frames on one of the link sets. The FTM measurement results are obtained when AP MLD 104 sends an FTM frame to the site MLD. AP MLD 104 can also calculate the measurement error of multiple FTM frames using the FTM measurement results.

[0053] For example, there are multiple links between AP MLD 104 and the site's MLD 102 set to transmit FTM frames. The number of links is n. Then, for the FTM measurement time N... i The measurement error obtained on link i (1≤i≤n) is denoted as e. i FTM measurement time N i error e i It can be the average error e i，avgThe average error is the average of n measurements. For each measurement, the AP MLD can obtain the error value. The FTM measurement time is N. i These error values ​​can be used to calculate the measurement error e. i .

[0054] In some implementations, the error value for each measurement can be calculated using neighboring APs with static locations. In other implementations, Bluetooth Low Energy (BLE) technology or Global Positioning System (GPS) technology can be used to calculate a reference location. The error value for each measurement is then calculated by comparing the measured location with the reference location.

[0055] In box 604, AP MLD 104 determines the error weights corresponding to the measurement errors. After AP MLD 104 determines the measurement errors for multiple measurements on the link, the error weights corresponding to those measurements can be calculated. The error weights corresponding to the measurement errors can be determined using some parameters of the link. For example, parameters may include at least one of the following: throughput priority, channel utilization, noise floor, physical layer (PHY) and media access control (MAC) capabilities, number of sites, and feedback from previous FTM measurements.

[0056] For example, for the measurement error e on link i i The corresponding weight is w i It can be calculated using the following equation (5).

[0057] w = f w (TP priority, chan util NF,PHY_MAC capibility client num (etc.) (5)

[0059] Among them TP priority Indicates throughput priority, chan util Indicates channel utilization, NF represents the noise floor, and PHY_MAC capibility This represents the capabilities of the physical layer and media access control layer, client. num This indicates the number of stations. Additionally, the input parameters may include feedback from previous FTM measurements. In some implementations, the function used to calculate the corresponding weights may be a function used to calculate the aforementioned scores for ease of calculation.

[0060] In box 606, AP MLD 104 determines the objective function based on measurement error and error weights. To achieve a small burst N and an appropriate total error E, the objective function is used to fulfill these requirements. The objective function can use measurement error and error weights as parameters.

[0061] For example, the objective function can be expressed as a weighted sum of the squared errors of each link.

[0062] The objective function (6) is shown below:

[0063]

[0064] In this objective function, the error weight w of link i can be adjusted. i and measurement counter N i This is to minimize the impact of errors on each link on the total error E as much as possible.

[0065] In block 608, AP MLD 104 defines several constraints corresponding to the objective function. For the objective function, certain constraints need to be set to obtain the optimal result. These constraints ensure that the objective function produces the best possible outcome.

[0066] For example, for the objective function (6) above, constraints (7), (8), (9) and (10) are as follows.

[0067]

[0068] max N i ≤Threshold N_MAX (9)

[0069] N i ≤Threshold N_link_i (10)

[0070] The above constraints ensure that the total error E does not exceed a certain threshold, hreshold. E Furthermore, the measurement count N of multiple links is limited to Threshold. N To minimize resource consumption or maximize efficiency. Threshold N This refers to the value mentioned in the example above. This value can be the example value of 64 (total FTM burst count), or other predefined thresholds. FTM measurements for a specific link or all links should be completed within a certain timeframe, i.e., N. i The maximum value / each cannot exceed a certain value.

[0071] In some implementations, if the APs to which the AP / STA MLD PHY / MAC conditions belong are similar, then w i e i N i This is the same across all links. Therefore, the total FTM measurement error can be expressed as the average of the measurement errors on each link, and it requires reusing the individual link / band FTM optimization method. For example, and

[0072] In box 610, AP MLD 104 determines the total measurement error and the total number of targets for FTM frames based on an objective function and multiple constraints. AP MLD 104 can utilize the aforementioned objective function and multiple constraints to calculate the optimal total measurement error and optimal number of FTM frames by trying different measurement errors and numbers of FTM frames.

[0073] Figure 7 A flowchart illustrating an example method for controlling an AP MLD according to an embodiment of the present disclosure is shown, with method 700 performed by the AP MLD. At 702, the AP MLD detects a set of parameters for each of a plurality of links between the AP MLD and a set of site MLDs. For example, the AP MLD may perform measurements on the plurality of links and obtain parameters for each of the plurality of links. For example, the AP MLD may detect channel utilization by transmitting some frames on a link. Furthermore, the AP MLD may also obtain the number of sites connected to the AP MLD via each link. For example, the AP MLD records all sites connected to it in an information table, including the links through which the sites connect to the AP MLD.

[0074] In 704, the AP MLD determines multiple scores for multiple links based on this set of parameters. For example, when the AP MLD obtains the parameter set for each of multiple links, it can calculate the link's score by inputting that parameter set into a function. Therefore, the AP MLD will generate multiple scores for multiple links. A link's score can be used to indicate link quality.

[0075] In 706, the AP MLD determines the set of links from multiple links for transmitting multiple Fine Time Measurement (FTM) frames based on multiple scores. For example, after the AP MLD obtains multiple scores, it selects the set of links to perform FTM measurements for transmitting the FTM frames. In this process, the AP MLD uses the scores of multiple links to select the link set.

[0076] In some implementations, the AP MLD selects one link from multiple links for transmitting all FTM frames between the AP MLD and the site's MLD set. The selected link may have the highest or lowest score, determined based on requirements. In some implementations, the AP MLD may select a set of links from multiple links. Each of the selected links in the set has a score greater than a threshold score. In this case, a subset of the multiple links is used to transmit all FTM frames between the AP MLD and the site's MLD set.

[0077] In some implementations, the AP MLD can select multiple links as a set of links. If a link has a score, it indicates that the link is available. Therefore, multiple links with multiple scores can be used to transmit FTM frames between the AP MLD and the site's MLD set. Thus, in this case, all of the multiple links are used to transmit FTM frames.

[0078] In 708, the AP MLD determines the number of FTM frames to be transmitted on one of a set of links based on multiple scores. Because the AP MLD obtains a score for each of the multiple links, the link score can be used to determine the number of FTM frames transmitted by that link. For example, when a link is selected to transmit FTM frames based on multiple scores, the number of FTM frames to be transmitted on that link is the total number of FTM frames. When multiple FTM frames are transmitted on multiple links, the AP MLD can determine the number of FTM frames to be transmitted on a single link based on the link scores. For example, the AP MLD can determine a ratio of the multiple scores, and then the AP MLD can determine the number of FTM frames to be transmitted on the link based on the ratio.

[0079] In 710, the AP MLD transmits a number of FTM frames to the site MLD set via one of the link sets. After determining the number of FTM frames to transmit on a link, the AP MLD can send that number of FTM frames as required. For example, when the AP MLD transmits FTM frames on one link, the other links in the multiple links will not transmit FTM frames. The time period during which FTM frames are transmitted on one of the multiple links differs from the time period during which FTM frames are transmitted on another of the multiple links.

[0080] In some implementations, the AP MLD can also detect the measurement results of the FTM frames transmitted on each link. The error of the measurement results is also used to determine the optimal measurement time and appropriate total error for all links.

[0081] In this way, the AP MLD can use some of the multiple links to transmit FTM frames, while using the other links to transmit service frames. This avoids time delays and interruptions in service between the AP and the site's MLDS set.

[0082] Figure 8 An example AP MLD 800 according to an embodiment of this disclosure is illustrated. For example... Figure 8As shown, the AP MLD 800 includes at least one processor 810; a memory 820 coupled to the processor 810; at least one antenna 840; at least one radio device 850; an Ethernet interface 860; a management interface 870; and a power interface 880. The memory 820 stores instructions 822, 824, 826, 828, and 830 to cause the processor 810 to perform actions according to a reference embodiment of this disclosure.

[0083] like Figure 8 As shown, memory 820 stores instructions 822 for detecting a set of parameters for each of multiple links between the AP MLD and the site MLD set. Memory 820 also stores instructions 824 for determining multiple scores for the multiple links based on the parameter set. Furthermore, memory 820 further stores instructions 826 for determining a set of links from the multiple links for transmitting multiple Fine Time Measurement (FTM) frames based on the multiple scores. Memory 820 also stores instructions 828 for determining the number of FTM frames to be transmitted on one link in the link set based on the multiple scores. Figure 8 As shown, memory 820 also stores instructions 830 for transmitting that number of FTM frames to the site MLD set via one of the links in the link set.

[0084] The stored instructions and their executable functions can be understood by referring to the implementation methods described above. For the sake of brevity, the details of instructions 822, 824, 826, 828, and 830 will not be discussed in this document.

[0085] At least one antenna 840 in the AP MLD 800 is a key component that allows the AP MLD 800 to communicate with wireless devices such as laptops, smartphones, and tablets. The primary function of at least one antenna 840 can be to transmit and receive wireless signals, converting electrical signals into radio waves for output communication, and vice versa for incoming signals.

[0086] At least one radio 850 component in the AP MLD 800 is responsible for wireless communication. This radio 850 component can handle data conversion between wired and wireless modes, enabling the AP MLD 800 to transmit and receive data over the air. During modulation, digital data from a wired network can be converted into radio waves for wireless transmission. During demodulation, incoming radio waves can be converted back into digital data that the AP MLD 800 can process. This radio 850 component can operate on a specific frequency band, such as 2.4 GHz, 5 GHz, or 6 GHz. This radio 850 component can ensure effective communication by selecting an appropriate channel to minimize interference. The performance of this radio 850 component can be defined by various Wi-Fi standards, including 802.11a / b / g / n / ac / ax, with newer standards such as Wi-Fi 6 and Wi-Fi 7 offering improved speed, efficiency, and capacity.

[0087] The Ethernet interface 860 in the AP MLD 800 can be used to connect the AP MLD 800 to a local network, thereby providing bridging between the wired and wireless segments of the network. The AP MLD 800 can be connected to a router, switch, or directly to the Internet via the Ethernet interface 860, enabling wireless devices to communicate with other network resources and the wider Internet. The Ethernet interface supports various speeds, including Fast Ethernet (e.g., 100 Mbps), Gigabit Ethernet (e.g., 1 Gbps), and even multi-gigabit Ethernet.

[0088] The management interface 870 in the AP MLD 800 allows network administrators to configure, monitor, and manage the AP MLD 800's settings and performance. The management interface 870 can be accessed through various methods, such as a web browser, command-line interface (CLI), or network management protocols like Simple Network Management Protocol (SNMP). Through the management interface 870, administrators can create and modify SSIDs, security protocols, VLANs, and other operational parameters to ensure the AP 800 operates effectively within the network environment.

[0089] The power interface 880 in the AP MLD 800 supplies the necessary power to the device, ensuring smooth and efficient operation. This can be achieved by using direct power from an AC adapter connected to a power outlet, or via Power over Ethernet (PoE), which delivers power through the same Ethernet cable used for data transmission.

[0090] Program code or instructions for performing the methods of this disclosure may be written in any combination of one or more programming languages. This program code or instructions may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be performed. The program code or instructions may be implemented entirely on a machine, partially on a machine, as a standalone software package, partially on a machine, partially on a remote machine, or entirely on a remote machine or server.

[0091] Program code or instructions for performing the methods of this disclosure may be written in any combination of one or more programming languages. This program code or instructions may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be performed. The program code or instructions may be implemented entirely on a machine, partially on a machine, as a standalone software package, partially on a machine, partially on a remote machine, or entirely on a remote machine or server.

[0092] In the context of this disclosure, a machine-readable medium can be any tangible medium that can contain or store a program for use in or in conjunction with an instruction execution system, apparatus, device, or equipment. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, devices, or any suitable combination thereof. More specific examples of machine-readable storage media will include electrical connectors having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0093] Furthermore, although the operations are described in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or in sequential order, or that all the operations shown be performed to achieve the desired result. In some cases, multitasking and parallel processing can be advantageous. Certain features described in the context of a single implementation may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0094] In the foregoing detailed description of this disclosure, reference has been made to the accompanying drawings, which form part of this disclosure, and examples of how this disclosure may be practiced are illustrated in the drawings by way of illustration. These examples have been described in sufficient detail to enable those skilled in the art to practice the examples of this disclosure, and it should be understood that other examples may be utilized and process, electrical, and / or structural changes may be made without departing from the scope of this disclosure.

Claims

1. A method, the method comprising: The access point (AP) multi-link device (MLD) detects the parameter set for each of the multiple links between the AP MLD and the site MLD set. The AP MLD determines multiple scores for the multiple links based on the parameter set; The AP MLD determines a set of links from the plurality of links for transmitting the plurality of fine time measurement (FTM) frames based on the plurality of scores; The AP MLD determines the number of FTM frames to be transmitted on one of the links in the link set based on the multiple scores; as well as The AP MLD transmits the number of FTM frames to the site MLD set via one of the links in the link set.

2. The method according to claim 1, wherein the parameter set includes at least one of the following: number of sites, channel utilization, site type, service priority, bandwidth, noise floor, received signal strength indication (RSSI), and feedback of previous FTM measurement results.

3. The method of claim 1, wherein determining the set of links from the plurality of links for transmitting the plurality of fine time measurement (FTM) frames comprises: The highest score is determined from the multiple scores for the multiple links; as well as The link that corresponds to the highest score among the plurality of links is determined as the link set.

4. The method of claim 1, wherein the link set includes the plurality of links, and determining the number of FTM frames to be transmitted on one of the links in the link set includes: Determine the total number of the plurality of FTM frames to be transmitted between the AP MLD and the site MLD set; as well as The number of FTM frames to be transmitted on each of the plurality of links is determined based on the total number and the plurality of scores.

5. The method of claim 4, wherein determining the total number of the plurality of fine time measurement (FTM) frames to be transmitted between the AP MLD and the site MLD set comprises: Determine the first number of the MLD set of the site; For each site in the MLD set of sites, determine a second number of FTM exchanges; as well as The total number for the plurality of FTM frames is determined based on the first number and the second number.

6. The method of claim 4, wherein determining the number of FTM frames to be transmitted on each link in the link set based on the total number and the plurality of scores comprises: Determine the ratio for the multiple scores; as well as The number of FTM frames to be transmitted on each link in the link set is determined based on the total number and the ratio.

7. The method of claim 4, wherein transmitting the number of FTM frames via one of the links in the set of links comprises: Determine the set of FTM frames from the stated number of FTM frames; as well as The FTM frame set is transmitted via one of the links in the link set during the target wake-up time (TWT) service period (SP), and the TWT SP is interleaved with the TWT SP on another link in the link set in time.

8. The method of claim 7, wherein transmitting the set of FTM frames via one of the links in the set during the target wake-up time (TWT) service period (SP) comprises: During the TWT SP, the set of FTM frames is transmitted to the first site MLD in the set of sites MLDs via one of the links in the set of links. as well as During the TWT SP, data communication between the AP MLD and other site MLDs in the site MLD set via one of the links in the link set is blocked.

9. The method of claim 8, wherein the TWT SP is one of the following: a standalone TWT SP, a broadcast TWT SP, or a restricted TWT SP.

10. The method according to claim 1, further comprising: Determine the measurement error for multiple FTM frames on one of the links in the set of links; Determine the error weights corresponding to the measurement error; as well as The total measurement error and the total number of targets for the FTM frames on the link set are determined based on the measurement error and the error weight.

11. The method of claim 10, wherein determining the error weight corresponding to the measurement error comprises: The error weight corresponding to the measurement error is determined based on at least one of the following: throughput priority, channel utilization, noise floor, physical layer PHY and media access control layer MAC capabilities, number of sites, and feedback from previous FTM measurements.

12. The method of claim 10, wherein determining the total measurement error and the total number of targets for the FTM frames on the link set based on the measurement error and the error weight comprises: The objective function is determined based on the measurement error and the error weight; Determine multiple constraints corresponding to the objective function; as well as The total measurement error and the total number of targets for the FTM frame are determined based on the objective function and the multiple constraints.

13. An access point (AP) multi-link device (MLD), the AP MLD comprising: At least one processor; A memory coupled to the at least one processor, the memory storing instructions for inducing the at least one processor to: Detect the parameter set for each of the multiple links between the AP MLD and the site MLD set. Multiple scores are determined for the multiple links based on the parameter set; Based on the multiple scores, a set of links for transmitting multiple fine time measurement (FTM) frames is determined from the multiple links; The number of FTM frames to be transmitted on one of the links in the link set is determined based on the multiple scores. as well as The number of FTM frames is transmitted to the site MLD set via one of the links in the link set.

14. The AP MLD of claim 13, wherein the set of parameters includes at least one of the following: number of clients, channel utilization, site type, service priority, bandwidth, noise floor, received signal strength indicator (RSSI), and feedback of previous FTM results.

15. The AP MLD of claim 13, wherein the instructions for determining a set of links from the plurality of links for transmitting a plurality of fine time measurement (FTM) frames include instructions for causing at least one processor to perform the following operations: Determine the highest score from the multiple scores for the multiple links; and The link that corresponds to the highest score among the plurality of links is determined as the link set.

16. The AP MLD of claim 13, wherein the link set includes the plurality of links, and the instructions for determining the number of FTM frames to be transmitted on one of the links in the link set include instructions for causing at least one processor to perform the following operations: Determine the total number of the plurality of FTM frames to be transmitted between the AP MLD and the site MLD set; and The number of FTM frames to be transmitted on each of the plurality of links is determined based on the total number and the plurality of scores.

17. The AP MLD of claim 16, wherein the instructions for determining the total number of the plurality of fine time measurement (FTM) frames to be transmitted between the AP MLD and the set of site MLDs include instructions for causing at least one processor to perform the following operations: Determine the first number of the MLD set of the site; For each site in the MLD set, determine a second number of FTM exchanges; and The total number for the plurality of FTM frames is determined based on the first number and the second number.

18. The AP MLD of claim 16, wherein the instructions for determining the number of FTM frames to be transmitted on each link in the link set based on the total number and the plurality of scores include instructions for causing at least one processor to perform the following operations: Determine the ratio of the multiple scores; and The number of FTM frames to be transmitted on each link in the link set is determined based on the total number and the ratio.

19. The AP MLD of claim 16, wherein the instructions for transmitting the number of FTM frames via said one link in the link set include instructions for causing at least one processor to perform the following operations: Determine the FTM frame set from the stated number of FTM frames; and The FTM frame set is transmitted via one of the links in the link set during the target wake-up time (TWT) service period (SP), and the TWT SP is interleaved with the TWT SP on another link in the link set in time.

20. A non-transitory computer-readable medium comprising instructions stored thereon, the instructions causing the AP MLD to: Detect the parameter set for each of the multiple links between the AP MLD and the site MLD set. Multiple scores are determined for the multiple links based on the parameter set; Based on the multiple scores, a set of links for transmitting multiple fine time measurement (FTM) frames is determined from the multiple links; The number of FTM frames to be transmitted on one of the links in the link set is determined based on the multiple scores. as well as The number of FTM frames is transmitted to the site MLD set via one of the links in the link set.

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