Method for connecting to access point by wireless communication device and wireless communication device

Abstract

In one aspect, the disclosure relates to a wireless communication device including, but not limited to, at least a wireless transceiver and a processor coupled to the wireless transceiver and configured to at least: establish, via the wireless transceiver, a first wireless connection with a first access point; determining whether a first wireless connection of the wireless communication device satisfies a roaming criterion; obtaining a subset of history records stored in the wireless communication device according to the first access point in the event the roaming criterion has been satisfied; ranking the access points in the subset of histories by obtaining scores of the access points based on the histories to generate a ranked access point list; selecting a second access point according to the hierarchical access point list; and establishing a second wireless connection with a second access point via the wireless transceiver.

Description

Technical Field

[0001] The present disclosure relates to a method used by a wireless communication device to connect to an access point and a wireless communication device using the method. Background Art

[0002] Wireless communication devices, such as mobile phones, laptops, tablets, or similar devices, have the advantage of being mobile, and the mobile nature of wireless communication devices may require that the network connection of the wireless communication devices be wireless in order to enable such wireless communication devices to remain connected to the network while traveling over long distances. After the wireless communication device has connected to a wireless access point (AP), such as a wireless fidelity (WiFi) access point, a router, a switch, a repeater, or any similar device, the wireless communication device may enter a roaming mode and begin scanning for an alternative channel belonging to another AP after the signal strength of the wireless connection with the AP has dropped below a certain threshold.

[0003] However, when scanning is performed while the wireless communication device is in roaming mode, the signal strength of the wireless connection to the original AP may continue to decrease. As the signal strength of the wireless connection to the original AP decreases, the data rate of the wireless connection will also decrease accordingly. For example, if the signal strength of the wireless connection decreases by -7.5 decibels (dB), the transmission speed may drop from 270 megabits per second (Mbps) to 108Mbps. If an alternative AP is not found quickly or the scanning time is too long, the signal quality is unlikely to improve. However, in some cases, even if the wireless communication device is able to switch to another AP fairly quickly after entering roaming mode, the transmission quality may still be poor due to the outdated scanning results causing the selection of the AP to be suboptimal. If the wireless communication device is located in a fast-moving vehicle, or if the wireless communication device moves a long distance, or if the scanning duration takes too much time, etc., the scanning results may quickly become outdated. In addition to reducing the moving speed of the wireless communication device, a technique to solve this problem may include reducing the number of channels used for scanning. The advantage of this technique is to reduce the scanning time at the expense of reducing the system bandwidth.

[0004] In addition, the task of scanning channels may take a significant amount of time. Currently, each dynamic frequency selection (DFS) channel may require at least 300 milliseconds (ms) to complete the scan, and each non-DFS channel may require 100 milliseconds to complete the scan. If the wireless communication device must scan 15 non-DFS channels and 16 DFS channels, it may take approximately 100ms*15+300*16=6300ms to complete a round of scanning. If the wireless communication device is traveling at high speed, the long scanning time may be a problem. Assuming that the wireless communication device is traveling at a train speed of 22m / s, the wireless communication device may travel 79.2 meters after 3.6 seconds. Since the wireless communication device may have moved away from the AP to which it last connected, such a long distance may cause the signal strength to drop and reduce the transmission quality.

[0005] In addition, fast moving speeds may result in the need for faster sampling speeds, so it may be necessary to reduce the number of channels to be scanned in order to reduce the scanning time. However, reducing the number of channels to be scanned will result in a reduction in the total system bandwidth available to the user. Assuming that the user initially has 20 channels available, limiting the channels to be scanned to only 3 channels will reduce the system bandwidth to only 3 / 20=15%, resulting in lower network capacity. This will result in the user having to compromise between travel speed and available network capacity. Summary of the invention

[0006] Therefore, the present disclosure relates to a method used by a wireless communication device to connect to an access point and a wireless communication device using the method.

[0007] In one aspect, the present disclosure relates to a method for a wireless communication device to connect to an access point. The method includes at least but is not limited to: establishing a first wireless connection with a first access point; determining whether the first wireless connection of the wireless communication device has met roaming criteria; if the roaming criteria have been met, obtaining a history record subset stored in the wireless communication device according to the first access point; ranking multiple access points in the history record subset by obtaining scores of the access points based on the history records to generate a ranked access point list; selecting a second access point according to the ranked access point list; and establishing a second wireless connection with the second access point.

[0008] In one aspect, the present disclosure relates to a wireless communication device, the wireless communication device at least including but not limited to a wireless transceiver electrically connected to a processor. The processor is configured to perform at least the following operations: establish a first wireless connection with a first access point via the wireless transceiver; determine whether the first wireless connection of the wireless communication device has met roaming criteria; if the roaming criteria have been met, obtain a history record subset stored in the wireless communication device according to the first access point; rank the access points in the history record subset by obtaining scores of the access points based on the history records to generate a ranked access point list; select a second access point according to the ranked access point list; and establish a second wireless connection with the second access point via the wireless transceiver.

[0009] In order to make the above features and advantages of the present disclosure easy to understand, exemplary embodiments are described in detail below in conjunction with the figures. It should be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the claimed disclosure.

[0010] However, it should be understood that this summary may not include all aspects and embodiments of the present disclosure, and is therefore not intended to be limiting or restrictive in any way. In addition, the present disclosure will include improvements and modifications that are obvious to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure.

[0012] Figure 1 A method used by a wireless communication device to connect to an access point according to an exemplary embodiment of the present disclosure is shown.

[0013] Figure 2 A method used by a wireless communication device to connect to an access point according to a first exemplary embodiment of the present disclosure is shown.

[0014] Figure 3 A method used by a wireless communication device to connect to an access point according to a second exemplary embodiment of the present disclosure is shown.

[0015] Figure 4 A hardware block diagram of a wireless communication device according to an exemplary embodiment of the present disclosure is shown.

[0016] Figure 5 The following is a diagram showing a process of scanning access points according to an exemplary embodiment of the present disclosure.

[0017] Figure 6An example of applying a simple additive weighting method to determine an AP with a highest score according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0019] In the following disclosure, measurement data of an AP or a channel is measured and recorded by a wireless communication device. For each AP, the measurement data may include one or more factors, such as signal strength, typically measured in decibels (dB), received signal strength indication (RSSI), signal to noise ratio (SNR), channel state information (CSI), distance information obtained via 802.11mc fine timing measurement (FTM) / timestamp (TM), CSI, SNR, RSSI, etc. For each channel, the measurement data may include one or more factors, such as spectrum analysis results, noise floor, channel utilization, and the number of APs operating on the channel. The spectrum analysis results are used to provide information related to interference on the channel. Each entry in the history record may be keyed by the media access control (MAC) address of the AP, while also recording the channel's measurement data for each AP operating on the channel. For example, assuming that both AP1 and AP2 are operating on channel 6 with a channel utilization of 50%, the historical records will be recorded as follows:

[0020] AP1 MAC, channel 6, channel utilization 50%

[0021] AP2 MAC, channel 6, channel utilization 50%

[0022] Factors for measuring data may vary depending on the design, and are not limited thereto.

[0023] The metric may be obtained according to one of the factors of the measurement data of the AP or the channel. For example, one of the factors is selected as the metric, or the metric is obtained by summing multiple factors by simple additive weighting, which is not limited herein.

[0024] The history records stored in the wireless communication device are a set of past measurement data. The history records may include measurement data of channels associated with each AP in the AP list. When the wireless communication device has been connected to an AP (e.g., the first AP), the past measurement data of the wireless communication device for other APs is also recorded in the wireless communication device and is referred to as a "history record subset". That is, each of the history record subsets corresponds to a different connection AP point.

[0025] As described above, since a wireless communication device moving at high speed may, for example, be moving away from a first AP or experiencing a degraded channel condition between the wireless communication device and the first AP, the wireless communication device may need to switch from the first (wireless) AP to the second (wireless) AP in order to maintain connection with the network. When the wireless communication device has satisfied the roaming criteria, the wireless communication device may need to switch to the second AP. Assume that after the wireless communication device has attached to the first AP, the wireless communication device can detect first measurement data of the first AP. The roaming criteria may include, for example, one or more of a signal strength threshold, an RSSI threshold, an SNR threshold, a CSI threshold, etc. When the first wireless connection between the wireless communication device and the first AP has satisfied the roaming criteria (for example, the RSSI of the first wireless connection has dropped below the RSSI threshold or any other metric in the first metric no longer satisfies its respective threshold), the wireless communication device may need to find a candidate AP as the second AP in order to maintain connection with the network. In order to effectively maintain connection with the network, the present disclosure provides a method used by a wireless communication device to connect to an access point and a wireless communication device using such a method.

[0026] exist Figure 1 The flow chart shown shows one of the concepts of the present invention. Figure 1 In step S101, it is assumed that the wireless communication device has established a first wireless connection with a first access point.

[0027] In step S102, the wireless communication device determines whether the first wireless connection of the wireless communication device meets the roaming criteria based on the real-time measurement data. For example, the wireless communication device can continuously or periodically detect the SNR or RSSI of the first wireless communication device to determine whether the SNR has dropped below the SNR threshold or the RSSI has dropped below the RSSI threshold. In another example, a metric can also be obtained based on the measurement data of the first wireless connection, and the wireless communication device determines whether the metric of the wireless communication device meets the roaming criteria.

[0028] In step S103, when the roaming criteria are met, the wireless communication device may obtain the history record subset according to the first access point. In other words, after the roaming criteria are met, the situation triggers the wireless communication device to search for a candidate AP in the AP list according to the history record subset. In this example, the wireless communication device is connected to the first AP in step S101, so the history record subset is the past measurement data of each AP recorded by the wireless communication device when it is connected to the first AP.

[0029] In step S104, the wireless communication device may perform ranking on the access points in the subset of the historical records by obtaining the scores of the APs based on the historical records to generate a ranked access point list. The ranking of the access points may not be performed on the entire AP list, but may be performed on a portion of the APs, for example, by filtering the AP list using a predefined criterion. For example, any AP in the AP list whose channel utilization is greater than 90% may be filtered out. The respective metrics of the APs are obtained based on the past measurement data for the APs that are not filtered out. The ranking of these APs may be performed based on the respective metrics of these APs. Since there may be multiple metrics for one AP, the AP ranking may be performed based on the metrics by a simple additive weighting method or a multi-level classification. The additive weighting method may be implemented by summing the weighted multiple metrics, wherein each metric is multiplied by a predetermined weight (e.g., weight 1*first metric+weight 2*second metric+…=score). After the scores have been calculated for each AP that has not been filtered out, the APs are ranked according to their respective scores.

[0030] In step S105, the wireless communication device may select a second AP according to the hierarchical access point list. Step S105 may be implemented based on the first exemplary embodiment or the second exemplary embodiment to be explained later. In step S106, after the second AP has been selected, the wireless communication device may establish a second wireless connection with the second AP and then disconnect the first wireless connection.

[0031] For the first exemplary embodiment, the wireless communication device may select a second AP by obtaining real-time measurement data of the AP based on the sorted channel list (i.e., performing a scan). In step S201, the wireless communication device may obtain a channel list based on a hierarchical access point list. In other words, each AP in the hierarchical AP list has previously been assigned a channel, which constitutes a list of channels to be sorted. In step S202, the wireless communication device may generate a sorted channel list based on the channel list. The channels may be sorted according to an order consistent with the hierarchical AP list. In step S203, the wireless communication device may collect at least some of the channels in the sorted channel list and the real-time measurement data and corresponding metrics of the corresponding APs in an order consistent with the order of the sorted channel list. It should be noted that the channel list is based on the order specified in the hierarchical AP list, where APs with better historical scores are scanned before APs with worse historical scores. In step S204, the wireless communication device obtains the scores of the APs based on the real-time measurement data and the historical records.

[0032] In detail, to obtain real-time measurement data of an AP, the wireless communication device may perform actions (eg, scanning, FTM, etc.) to obtain real-time measurement data of some or all channels in the sorted channel list based on the order specified in the sorted channel list.

[0033] Specifically, the wireless communication device may jump to a channel in the first sorted channel and then perform a scan, FTM, etc. Spectrum scanning and channel analysis may also be performed sequentially or simultaneously. The wireless communication device may then jump to a second channel in the second sorted channel and perform a scan. Similarly, the wireless communication device may jump to the remaining channels and perform scans respectively. Real-time measurement data is applied to the APs associated with the channels. For example, if AP1 and AP2 are on channel 1, a real-time record of the channel will be recorded for both AP1 and AP2.

[0034] Therefore, the real-time score of each AP can be obtained according to the real-time measurement data of the channel obtained by scanning and the metric corresponding to the real-time measurement data, and the wireless communication device can perform real-time ranking according to the real-time score of each AP and the historical ranking. In another example, the real-time score of each AP can be obtained according to the real-time measurement data obtained by scanning and the metric corresponding to the real-time measurement data, and the real-time score of each AP can also be obtained according to the past measurement data and the metric corresponding to the past measurement data, but it is not limited thereto.

[0035] According to step S204, based on the metrics obtained from the scanned APs and scanned channels, the wireless communication device can calculate the scores of the APs associated with some or all of the channels in the sorted channel list by applying a weighted sum to some or all of the collected real-time metrics and the metrics in the history of each of some or all of the channels stored. Additionally, the wireless communication device may not obtain the real-time metrics of all the channels in the sorted channel list, but may only need to obtain the real-time metrics of a predetermined number of channels and a predetermined number of associated APs. Specific examples will be provided later in this disclosure. Since the wireless communication device may not obtain the real-time measurement data of all the channels in the sorted channel list, but may only need to obtain the real-time measurement data of a predetermined number of channels and a predetermined number of associated APs, the time for switching to another AP is saved. Specific examples will be provided later in this disclosure.

[0036] For the second exemplary embodiment, the second exemplary embodiment can be applied to an emergency situation (e.g., when the wireless communication device has lost or is about to lose the network connection of the wireless communication device and urgently needs to connect to an alternative AP). Referring to Figure 3 , in step S301, the wireless communication device has detected an emergency situation (e.g., connection loss or RSSI / SNR far below the RSSI / SNR threshold). In step S302, the wireless communication device can select an AP based only on the sorted access point list generated according to step S104 without the need for any real-time measurement data (i.e., without performing scanning or measurement). For example, in the case of not obtaining real-time measurement data, the wireless communication device can select and connect to the AP with the best historical score according to the sorted access point list. In step S303, if the connection to the AP with the best historical score has failed, the wireless communication device can select and connect to the AP with the second-best score according to the sorted access point list. Essentially, according to the second exemplary embodiment, in response to the roaming criteria being met, the wireless communication device can generate a sorted AP list with reference to the previous measurement data recorded in the storage device (e.g., Figure 2 shown in S103, S104). Next, the wireless communication device can select a candidate AP based on the history according to any AP with the best score in the sorted AP list. A decision can be made without performing any real-time metric measurements, or a decision can be made by performing a small number of measurements as long as the results of the measurements are acceptable.

[0037] Figure 41 is a hardware block diagram of a wireless communication device 400 according to an exemplary embodiment of the present disclosure. The wireless communication device may include, but is not limited to, a processor 401 connected to a transceiver 402 and a storage device 403. The processor 401 may be a central processing unit (CPU), a microprocessor, a microcontroller, a field programmable gate array (FPGA), a graphics processing unit (GPU), a custom integrated circuit, or a device having similar functions.

[0038] The transceiver 402 may include one or more wired transceiver modules or wireless transceiver modules. For example, the transceiver 402 may include a wireless transceiver that enables the wireless communication device 400 to receive data at a radio frequency (RF) or a millimeter wave frequency. For example, the transceiver 402 may include a WiFi transceiver or a Bluetooth transceiver that meets the 802.xx standard. For example, the transceiver 402 may include a universal serial bus (USB) port or an interface that facilitates cable connection. For example, the transceiver 402 may also include a short-range wireless transceiver, such as a near field communication (NFC) transceiver.

[0039] The storage device 403 may be any non-volatile storage medium for non-volatile information storage, such as a flash memory, a hard disk drive (HDD), a read only memory (ROM), etc. The information to be stored may include information such as the above-mentioned history records and programming codes to be loaded into the processor 401 for execution. Figures 1 to 3 The functions described in Figure 5 to Figure 6 The specific example shown.

[0040] Figure 5 A specific example related to the first exemplary embodiment is shown. It is assumed that the wireless communication device (eg, 400) is located in a mobile environment or a stationary environment and is connected to a first AP via a first wireless connection. Figure 5In the first graph 501 shown, it is assumed that it takes time S1 to scan the complete channels of one cycle, and it takes time S2 to scan the channels of another cycle. Under the assumption that there are 15 non-DFS channels and 16 DFS channels, the duration S1 and the duration S2 may currently each be approximately 6250 ms, so that the scanning of each of S1 and S2 may each require, for example, (15*150 ms+16*250 ms)=6250 ms. If the scanning time is too long, when the wireless communication device detects the metric 512 of the second access point at the second time point T2 close to the roaming criteria 521, the metric 511 of the first AP may drop significantly due to the moving speed of the wireless communication device, and thus the wireless communication device may lose the network connection of the wireless communication device.

[0041] Figure 5 The second graph 502 shown provides a solution to the above problem by shortening the scanning time from S1 and S2 to S3 and S4, respectively. In this way, although the metric 513 of the first AP may decrease as the wireless communication device moves away from the first AP, when the wireless communication device detects that the metric 514 of the first AP drops below the roaming criteria 522 at the third time point T3, the wireless communication device may start searching for the channel of an alternative AP for time S3 in one cycle, and then search for the channel of the AP for time S4 ​​in another cycle. Since time S3 and time S4 ​​are shorter, the wireless communication device can find a suitable AP at the fourth time point T4 by detecting the acceptable real-time metric 514 of the second AP, and the real-time metric 513 of the first AP will not drop too low. Therefore, one of the purposes of the present disclosure is to enable the wireless communication device to shorten the time to connect to an alternative AP.

[0042] When a user enables a wireless function (e.g., WiFi) of a wireless communication device (e.g., a laptop or mobile phone), if the wireless communication device is located in a densely populated urban area, the wireless communication device may detect numerous WiFi APs. However, some channels or some WiFi APs may have low metrics and therefore the priority of the wireless communication device to connect to the channels or WiFi APs is low. The use of a combination of historical records and real-time data disclosed in the present invention not only filters out unwanted channels and APs, but also re-prioritizes the order in which the channels of access points are scanned. By filtering out unwanted channels of access points and re-ordering the scan order, the scan duration of each scan cycle can be shortened. In this way, the detection time can be reduced so that full network capacity can be obtained when operating at higher speeds.

[0043] As an example, assume that the wireless communication device (e.g., 400) has been connected to the first AP (e.g., S101) through the first wireless connection that meets the roaming criteria (e.g., 521, 522). For example, the SNR or RSSI of the first wireless connection may be lower than a predetermined SNR threshold or a predetermined RSSI threshold. The wireless communication device may continue to determine whether the measurement data of the first wireless connection has met the roaming criteria (S102). Next, the wireless communication device may refer to the storage device (e.g., 403) of the wireless communication device to obtain a history record subset, which includes the history of measurement data of APs and channels corresponding to the APs (S103). For example, the history record may record AP1, AP2, AP3, AP4, AP5 and AP6 and the channels corresponding to the APs, and the history record subset may be a record of the APs during the period when the communication device is connected to the first AP. In addition, since the channel utilization of AP1 and AP2 is greater than the predetermined channel utilization threshold, AP1 and AP2 are filtered out, and the predetermined channel utilization threshold may be, for example, 90%. Next, the APs in the history record subset are ranked based on the historical metrics of the APs that have been recorded when the measurements were performed in the past, and a ranked list of access points is generated accordingly (S104). In detail, the ranked list of APs has the following order, which includes AP3 AP4 AP5 AP6, where AP3 has the best score. Next, it is assumed that AP3 corresponds to channel 36, AP4 corresponds to channel 11, AP5 corresponds to channel 36, and AP6 corresponds to channel 1 (S201), and thus based on the ranked list of APs, the ranked channel list (S202) will have the following order, which includes channel 36, channel 11, and channel 1. Since there are no duplicate channels in the ranked channel list, the second instance of channel 36 (i.e., AP5 corresponds to channel 36) will not be included in the ranked channel list.

[0044] Next, assuming that the wireless communication device has encountered a non-emergency situation, the wireless communication device will obtain real-time measurement data (S203), for example, by performing scanning, FTM, and spectrum scanning on channel 36, channel 11, and channel 1 and the corresponding APs. According to an exemplary embodiment, the wireless communication device may perform scanning in the same order as the sorted channel list. This means that the order of channel scanning is in the order of channel 36, channel 11, and channel 1. More specifically, the communication device first jumps to channel 36 and performs interaction (e.g., scanning, FTM, etc.) of channel 36 with the APs (e.g., AP3 and AP5) in channel 36. Then the communication device jumps to channel 11 and performs interaction of channel 11 with the APs (e.g., AP4) in channel 11. Then the communication device jumps to channel 1 and performs interaction of channel 1 with the APs (e.g., AP6) in channel 1. According to an exemplary embodiment, the wireless communication device may perform scanning only on a portion of the listed channels or sorted channels and each of the APs corresponding thereto. Therefore, the wireless communication device may only need to perform a scan on channel 36 and channel 11 and AP3 and AP4, but does not need to perform a scan on channel 1 and AP6.

[0045] After the above-mentioned collection of real-time measurement data and metrics corresponding to the real-time measurement data has been performed, the wireless communication device can obtain the score of the AP based on the real-time measurement data and the past measurement data (S204). The score can be based on simple additive weighting or can be based on other methods that can solve multi-criteria decision-making (MCDM), such as machine learning. After applying one or more of these methods, each AP will be marked with a score. The wireless communication device will select the AP with the highest score to establish a new wireless connection (S205).

[0046] Figure 6An example of applying a simple additive weighting method to determine the AP with the highest score is shown. As in the previous example, the candidate APs taken into consideration include AP3, AP4, and AP6, and the APs are ranked using four criteria, but it should be noted that the present disclosure does not limit the ranking of APs to these exact criteria. In this example, the first criterion is the roaming record from the historical record, the second criterion is the RSSI of each of AP3, AP4, and AP6, the third criterion is the noise floor of channel 36, channel 11, and channel 1 corresponding to AP3, AP4, and AP6, and the fourth criterion is the channel utilization of channel 36, channel 11, and channel 1. The second criterion, the third criterion, and the fourth criterion can be historical metrics or measured real-time metrics. For each of the APs, the accumulated score is obtained by multiplying each of the criteria by its respective weighting coefficient. For example, the accumulated score of AP3 is determined by the sum of the first roaming record multiplied by the first weighting coefficient (W1), the first RSSI multiplied by the second weighting coefficient (W2), the first noise floor multiplied by the third weighting coefficient (W3), and the fourth weighting coefficient (W4) multiplied by the first channel utilization rate. In addition, the sum of the weighting coefficients W1, W2, W3, and W4 is 1. As an example, W1=0.2, W=0.15, W3=0.4, W4=0.25, but the present disclosure is not limited to these exact numbers as weighting coefficients.

[0047] As another example, assume that the wireless communication device has detected an emergency situation (e.g., the first wireless connection with the first AP is severed) (S301). In this example, the wireless communication device will perform steps S101 to S103, and assume that AP3, AP4, and AP6 in the hierarchical AP list and channel 36, channel 11, and channel 1 in the sorted channel list are also obtained. Next, since AP3 has the best score according to the hierarchical access point list generated from step 104, the wireless communication device can select AP3 from the hierarchical AP list. Therefore, the wireless communication device can directly connect to AP3 without performing any measurements (S302). Since AP4 has the second best score in the hierarchical access point list, if the connection with AP3 has failed, the wireless communication device can try to connect to AP4 (S303).

[0048] In addition, the history record may be updated periodically, and obsolete channels or access points in the history record may be deleted. For example, when the wireless communication device has a wireless connection with a sufficiently high metric (e.g., a wireless connection with an SNR above a threshold), the wireless communication device may perform a full channel scan on detectable channels every predetermined time period (e.g., 5 minutes or 10 minutes), and then update the history record accordingly. After performing a full scan, APs with low scores may be removed from the history record. In addition, undetectable or unupdatable APs may also be removed from the history record. There is a predefined aging time associated with the history record. For data obtained before the predefined aging time, the data may be removed from the history record.

[0049] In summary, the present disclosure is suitable for use in a wireless communication system and can shorten the time for connecting to a new access point when a wireless communication device has satisfied a roaming criterion.

[0050] Unless explicitly stated, the elements, actions or instructions used in the detailed description of the disclosed embodiments of the present application should not be considered as absolutely critical or necessary to the present disclosure. In addition, each of the indefinite articles "a and an" used herein may include more than one item. If only one item is involved, the term "single (single)" or similar language will be used. In addition, the term "any one of ... " used herein with a series of multiple items and / or multiple item categories is intended to include "any one of ... ", "any combination of ... ", "any multiple of ... " and / or "any combination of multiple items and / or item categories" individually or in combination with other items and / or other item categories. In addition, the term "group" used herein is intended to include any number of items (including zero). In addition, the term "number" used herein is intended to include any number (including zero).

[0051] It will be apparent to those skilled in the art that various modifications and changes may be made to the structure of the disclosed embodiments without departing from the scope or spirit of the present disclosure. In summary, the present disclosure is intended to cover modifications and variations of the present disclosure that fall within the scope of the following claims and their equivalents.

Claims

1. A method for connecting to an access point by a wireless communication device, the method include: establishing a first wireless connection with a first access point; determining whether the first wireless connection of the wireless communication device has satisfied a roaming criterion; obtaining, based on the first access point, a subset of the history records stored in the wireless communication device in a case where the roaming criteria have been met; ranking a plurality of access points in the subset of historical records by obtaining scores for the access points based on the subset of historical records to generate a ranked list of access points; selecting a second access point according to the ranked access point list; as well as A second wireless connection is established with the second access point.

2. The method according to claim 1, further comprising: include: obtaining a channel list according to the hierarchical access point list, each of a plurality of channels in the channel list corresponding to one of the plurality of access points in the hierarchical access point list; as well as An ordered channel list is generated from the plurality of channels in the channel list based on an order consistent with the order of the ranked access point list.

3. The method according to claim 2, further comprising: include: collecting real-time measurement data for each of at least some of the plurality of access points and each of at least some of the plurality of channels in the ordered channel list, obtaining an access point score based on the collected real-time measurement data and the historical record subset, and The second access point having the highest score is selected.

4. The method of claim 3, wherein the real-time measurement data of each of the at least some of the plurality of access points comprises one or more of distance information, channel state information (CSI), signal-to-noise ratio (SNR), and received signal strength indication (RSSI).

5. The method of claim 3, wherein the real-time measurement data for each of the at least some of the multiple channels in the sorted channel list comprises one or more of spectrum analysis results, noise floor, channel utilization, and number of access points per channel.

6. The method according to claim 1, further comprising: include: An emergency situation is detected; as well as Selecting the second access point according to the ranked access point list includes selecting the second access point according to the ranked access point list without using real-time measurement data.

7. The method according to claim 6, further comprising: include: detecting that the second wireless connection with the second access point has failed; as well as A next best access point is selected based on the ranked access point list.

8. The method of claim 1, wherein the roaming criteria comprises at least one of a signal strength threshold, a signal-to-noise ratio (SNR) threshold, a received signal strength indication (RSSI) threshold, a channel state information (CSI) threshold, and a distance information threshold.

9. A wireless communication device, include: Wireless transceiver; as well as A processor coupled to the wireless transceiver and configured to perform at least the following operations: establishing a first wireless connection with a first access point via the wireless transceiver, determining whether the first wireless connection of the wireless communication device has satisfied a roaming criterion, obtaining a subset of the history records stored in the wireless communication device according to the first access point if the roaming criteria have been met, ranking a plurality of access points in the historical record subset by obtaining scores of the access points based on the historical record subset to generate a ranked access point list, selecting a second access point based on the ranked access point list, and A second wireless connection is established with the second access point via the wireless transceiver.

10. The wireless communication device of claim 9, wherein in response to generating the ranked access point list, the processor is further configured to: obtaining a channel list according to the hierarchical access point list, each of a plurality of channels in the channel list corresponding to one of the plurality of access points in the hierarchical access point list, and An ordered channel list is generated from the plurality of channels in the channel list based on an order consistent with the order of the ranked access point list.

11. The wireless communication device of claim 10, wherein the processor is further configured to: collecting real-time measurement data for each of at least some of the plurality of access points and each of at least some of the plurality of channels in the ordered channel list, obtaining an access point score based on the collected real-time measurement data and the historical record subset, and The second access point having the highest score is selected.

12. The wireless communication device of claim 11, wherein the real-time measurement data of each of the at least some of the plurality of access points comprises one or more of distance information, channel state information (CSI), signal-to-noise ratio (SNR), and received signal strength indication (RSSI).

13. A wireless communication device according to claim 11, wherein the real-time measurement data of each of the at least some of the multiple channels in the sorted channel list includes one or more of spectrum analysis results, noise floor, channel utilization, and number of access points per channel.

14. The wireless communication apparatus of claim 9, wherein the processor is further configured to: An emergency situation is detected; and The second access point is selected from the ranked list of access points in response to detecting the emergency situation without using real-time measurement data.

15. The wireless communication apparatus of claim 14, wherein the processor is further configured to: A next best access point is selected based on the ranked access point list in response to the second wireless connection with the second access point having failed.

16. The wireless communication device of claim 11, wherein the roaming criteria comprises at least one of a signal strength threshold, a signal-to-noise ratio (SNR) threshold, a received signal strength indication (RSSI) threshold, a channel state information (CSI) threshold, and a distance information threshold.

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