GPS assisted cooperation and signaling assisted wlan dfs operation

Abstract

Methods and systems are disclosed for WLAN devices to select an operating dynamic frequency selection (DFS) channel that minimizes radar interference probability by using assistance information. The assistance information can be a crowd-sourced database of radar zones with geographic markers, including one or more DFS channels used within the radar zones with geographic markers detected by multiple WLAN devices. The WLAN devices can query the crowd-sourced database for nearby radar zones with geographic markers to determine if radar is operating on an overlapping DFS channel so that it can switch to a different channel. In an aspect, the assistance information can be a periodic special action frame broadcast by a WLAN beacon device over the operating channel of the WLAN device. The special action frame can carry information about one or more channels used by nearby radar and a recommended alternative channel for use by the WLAN device.

Description

[0001] Related applications

[0002] This application is an international application of U.S. non-provisional application No. 16 / 299,850, filed on March 12, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] In general, the subject matter technology relates to wireless local area network (WLAN) systems, and more specifically, to systems and methods for devices or vehicles operating in a WLAN dynamic frequency selection (DFS) channel to minimize interference to coexisting radar systems. Background Technology

[0004] WLAN systems compliant with the IEEE 802.11 standard can operate in the 2.4 GHz, 5 GHz, or higher frequency bands. Channels in the 5 GHz band are classified as indoor or outdoor channels based on their permitted usage. Outdoor WLAN channels in the 5 GHz band are increasingly used for in-vehicle networks and between vehicles to exchange information and to receive information from system infrastructure to assist autonomous driving and other applications. In some countries, some (if not all) outdoor 5 GHz WLAN channels are also used by radar (e.g., weather, military, and civilian radar). These 5 GHz channels where WLAN and radar operation coexist are called Dynamic Frequency Selection (DFS) channels. WLAN devices with the ability to detect the presence of radar in their operating frequencies and guide their connected network members away from the radar's operating frequencies are called WLAN DFS masters. WLAN devices lacking this capability and relying on masters to operate in DFS channels are called slave devices.

[0005] To minimize radar interference from WLAN devices, regulatory agencies in many jurisdictions impose stringent requirements on the behavior of WLAN devices operating in DFS channels. For example, before a WLAN DFS master device can begin transmitting in a WLAN DFS channel, a radar scan, known as a Channel Availability Check (CAC), is required to detect radar signals. This CAC can last from one minute for civilian radar to ten minutes or more for weather and military radar. During CAC, any WLAN operation by the WLAN DFS master device can be prohibited. If no radar signal is detected, the WLAN DFS master device can operate in that channel. During operation, the WLAN DFS master device needs to continuously monitor the same channel for any radar signals during a process known as In-Service Monitoring (ISM). If a radar signal is detected at any point during CAC or ISM in a DFS channel, the WLAN DFS master device is expected to quickly move to a different channel. If this second channel is also another DFS channel, the WLAN DFS master device may have to perform CAC and ISM again until a DFS channel without radar signals is found.

[0006] Radar can emit narrow-beam radio pulses that rotate 360 ​​degrees around the radar. Because vehicles are constantly moving, WLAN DFS master devices deployed in vehicles may not accurately detect radar signals compared to stationary equipment. Even if the WLAN DFS master device detects a radar signal, the information collected about the detected signal may become outdated as the vehicle moves to different locations. Inaccurate and outdated radar detection and signal information can lead to unreliable WLAN DFS operation, potentially resulting in increased interference with radar operation. Furthermore, interruptions to WLAN operation of the WLAN DFS master device during the long CAC period used to scan radar signals can cause network interruptions for end users' WLAN operations on slave devices. Attached Figure Description

[0007] The described embodiments and their advantages can be best understood by referring to the following description taken in conjunction with the accompanying drawings. These drawings do not in any way limit any changes in form and detail that may be made to the described embodiments by those skilled in the art without departing from the spirit and scope thereof.

[0008] Figure 1 An example outdoor wireless local area network (WLAN) architecture for automotive deployment is shown, according to some embodiments of this disclosure.

[0009] Figure 2A collaborative network server for accessing geotagged radar jamming data, according to some embodiments of this disclosure, is illustrated as an example system for assisting in the selection of WLAN Dynamic Frequency Selection (DFS) channels.

[0010] Figure 3 A local database of interference data from geotagged radar, according to some embodiments of this disclosure, is shown as an example system for assisting in the selection of WLAN DFS channels.

[0011] Figure 4 A flowchart illustrating a method for a WLAN device deployed in a vehicle to access a collaborative network server or local database of geotagged radar interference data as an aid in selecting a WLAN DFS channel, according to some embodiments of this disclosure, is shown.

[0012] Figure 5 This is a block diagram illustrating a WLAN DFS device deployed in a vehicle according to some embodiments of the present disclosure, configured to access a collaborative network server or local database of geotagged radar interference data as an aid in selecting a WLAN DFS channel.

[0013] Figure 6 An example system is shown in which a car receives DFS action frames from a beacon device as an aid for selecting a WLAN DFS channel, according to some embodiments of the present disclosure.

[0014] Figure 7 A flowchart illustrating a method for a WLAN device deployed in a vehicle to receive a DFS beacon from a beacon device as an aid for selecting a WLAN DFS channel, according to some embodiments of the present disclosure, is shown.

[0015] Figure 8A This is a block diagram of a DFS action frame beacon device according to some embodiments of the present disclosure.

[0016] Figure 8B This is a block diagram of a WLAN DFS device deployed in a vehicle according to some embodiments of the present disclosure, the WLAN DFS device being configured to receive DFS action frames from a beacon device as an aid for selecting a WLAN DFS channel. Detailed Implementation

[0017] Examples of various aspects and variations of the subject matter are described herein and illustrated in the accompanying drawings. The following description is not intended to limit the invention to these embodiments, but rather to enable those skilled in the art to make and use the invention.

[0018] In one aspect of the subject matter, a database of radar interference sources can be collected from wireless local area network (WLAN) devices deployed in one or more vehicles and queried by the WLAN devices in the field to help them select an Operational Dynamic Frequency Selection (DFS) channel that minimizes the probability of radar interference. In one embodiment, information about radar interference can be crowdsourced from vehicles operating in the field, equipped with WLAN devices that support reporting information about radar signals detected on DFS channels. WLAN devices (e.g., WLAN DFS masters) can detect the presence of radar signals and report information such as the detection location, the DFS channel used, and the operating time to a central server, which then incorporates the reported information into a database. WLAN devices in the vehicle wishing to operate on DFS channels (including slave devices that do not have the capability to detect radar signals) can query the database for information about potential nearby radar signals to select a DFS channel with a reduced probability of radar interference.

[0019] In one embodiment, the radar interference database can be stored locally in the WLAN device or on the vehicle, rather than at a centralized server. The WLAN device can store information about radar interference detected over time in the local database. When the vehicle approaches a location, the WLAN device can query the local database to avoid DFS channels with potential radar interference. Advantageously, by utilizing the database of radar information remotely or locally, the need for Channel Availability Check (DFS-CAC) can be reduced, and WLAN operation can continue without interruption due to DFS-CAC scanning.

[0020] In another aspect of the subject matter, a dedicated WLAN beacon device located at the boundary of radar interference range can broadcast DFS beacons or special action frames to inform or warn WLAN devices about the radar interference range in which a vehicle is approaching radar operation and to avoid the DFS channel used by the radar. The WLAN beacon device can broadcast periodic special action frames carrying information about: the DFS channel used by nearby radar, the range of radar interference or the GPS coordinates of the boundary of the radar interference range, and the recommended DFS candidate channel for the WLAN device to switch to. The WLAN beacon device can broadcast special action frames on the same overlapping WLAN DFS channel as the radar signal but outside the boundary of the radar interference range, so the action frames do not interfere with radar operation. When a vehicle approaches the boundary of radar interference, the WLAN device operating on the same DFS channel as the radar signal can receive the special action frames and can switch to a different DFS channel before the vehicle enters the radar interference range. Advantageously, because the special action frames are received as WLAN packets, both the DFS master and slave devices can quickly and reliably switch to different DFS channels to avoid the DFS channel carrying the radar signal.

[0021] Figure 1 An example outdoor wireless local area network (WLAN) architecture for vehicle deployment according to some embodiments of this disclosure is illustrated. WLAN devices can be deployed in vehicles 101 and 103 to communicate using the IEEE 802.11 standard. The WLAN devices can be user stations (STAs) configured to associate with an access point (AP) 105 deployed by the road when vehicles 101 and 103 enter the range of AP 105. The WLAN devices in vehicles 101 and 103, along with AP 105, can form a basic service set (BSS). Once associated with AP 105, the WLAN devices can receive information from AP 105 such as road conditions, traffic conditions, environmental and other infrastructure information to assist vehicles 105 and 103 in navigating the road. In one scenario, vehicles 101 and 103 can use the WLAN devices to exchange vehicle information, such as speed, heading, etc., in peer-to-peer communication without routing data traffic through AP 105. Vehicles 101 or 103 can use information received from each other and / or from AP 105 to facilitate autonomous driving. In another scenario, vehicle 101 can host a SoftAP or peer group owner (P2P GO) that can be connected to by in-vehicle WLAN clients inside vehicle 101 (e.g., WLAN-enabled mobile phones carried by passengers or in-vehicle entertainment consoles in passenger seats), through which infotainment content can be exchanged.

[0022] The WLAN system can operate on one or more 5GHz WLAN DFS channels shared with the radar system. The WLAN device in vehicle 101 or 103 can be a WLAN DFS master, configured to detect the presence of radar signals in the operating channel and, if radar interference is detected, guide itself and connected slave devices without radar detection capabilities away from the operating channel. Regulations may require the WLAN DFS master to perform a DFS-CAC scan for a minimum period to ensure the DFS channel is free from radar interference before the WLAN DFS master can begin operating in the channel. During operation after DFS-CAC clearance, the WLAN DFS master may still need to use In-Service Monitoring (ISM) to continuously monitor the operating channel for any radar signals. If a radar signal is detected at any time during CAC or ISM in the DFS channel, it is expected that the WLAN DFS master and connected slave devices will quickly move to a different channel. To help the WLAN device select a DFS channel with a reduced probability of radar interference and reduce interference to radar operation caused by the WLAN device, helpful information about radar interference can be provided to the WLAN device.

[0023] The examples, implementations, and embodiments described herein are primarily set within the context of WLAN. In one embodiment, the WLAN system can be a WLAN network using various versions of the IEEE 802.11 standard. However, other WLAN systems are conceivable.

[0024] Figure 2 A cooperative network server 206 for accessing geotagged radar interference data by vehicles, according to some embodiments of this disclosure, is illustrated as an example system for assisting in the selection of WLAN DFS channels. Three vehicles are shown: vehicle 201, vehicle 203, and vehicle 209.

[0025] A vehicle 201, possibly equipped with an onboard WLAN DFS master device, may drive into the operating range 207 of radar 205. In one example, radar 205 could be an air traffic radar operating at an airport. Before vehicle 201 enters the operating radar range 207, the WLAN DFS master device can initially operate on the DFS channel. If radar 205 operates on the same DFS channel as vehicle 201, the WLAN DFS master device's DFS-ISM scan can detect the radar signal on the operating DFS channel after vehicle 201 enters the operating radar range 207. Furthermore, the WLAN DFS master device can record the DFS channel of radar 205, the GPS coordinates of vehicle 201, and the time when the radar signal was detected by the DFS-ISM scan. The recorded GPS coordinates can represent a geographic point on the boundary of the operating radar range 207. The recorded time can represent the time radar 205 was operating. The WLAN DFS master device can upload information about the detected radar signal to a cooperative network server 206, including the radar 205's DFS channel, the recorded GPS coordinates, and the recorded time. In one embodiment, the WLAN DFS master device can communicate with the cooperative network server 206 via a cellular network operating in GSM, LTE, 5G, or other types of wide area networks. In another embodiment, the cooperative network server 206 can connect to a wide area network via the Internet.

[0026] Similarly, vehicle 203 (another vehicle equipped with a WLAN DFS master device) can travel into the operating radar range 207. If the WLAN DFS master device on vehicle 203 operates on the same DFS channel as radar 205, its DFS-ISM scan can similarly detect radar signals on the operating DFS channel when vehicle 203 enters the operating radar range 207. In one embodiment, the DFS channel detected by vehicle 203 can be the same as the DFS channel detected by vehicle 201. In one embodiment, if radar 205 changes its operating DFS channel, the DFS channel detected by vehicle 203 can be different from the DFS channel detected by vehicle 201. As in vehicle 201, the WLAN DFS master device on vehicle 203 can record the DFS channel of radar 205, the GPS coordinates of vehicle 203, and the time when its DFS-ISM scan detected radar signals. Therefore, the recorded GPS coordinates can represent another geographic point on the boundary of the operating radar range 207, and the recorded time can represent another time when radar 205 is operating. The WLAN DFS master device on vehicle 203 can similarly upload information about the detected radar signals to the cooperative network server 206, including the DFS channel of radar 205, the recorded GPS coordinates, and the recording time.

[0027] The collaborative network server 206 can store information about detected radar interference collected from vehicles 201, 203, and others into a centralized database. Therefore, the crowdsourced database can represent estimated boundaries of multiple radar zones in GPS coordinates, the DFS channels on which the radars are expected to operate, and the estimated times of their operation. In one embodiment, the crowdsourced database can be updated or overwritten as the operating parameters of existing radars are modified, new radars come online, or old radars cease service. Information not updated during a threshold time period can be declared obsolete and deleted from the database.

[0028] Its WLAN device may want vehicles operating in a DFS channel at a specific geographic location at a particular time to query a central database for potential radar interference near the desired geographic location and the required time, to determine whether the DFS channel is clear or whether it can be cautiously switched to another DFS channel to reduce the probability of radar interference. In one embodiment, the cooperative network server 206 can analyze the operational characteristics of radar zones contained in a centralized database to suggest a DFS channel that minimizes the probability of radar interference based on the location and time of the queried vehicle. In one embodiment, the vehicle may periodically send its current GPS coordinates to the cooperative network server 206 to receive information about any potentially approaching radar zones. If this information indicates that a radar zone is approaching, the vehicle may proactively switch to a DFS channel to avoid any radar interference.

[0029] For example, vehicle 209 may periodically send its GPS coordinates to cooperative network server 206. The onboard WLAN device 209 may be a WLAN DFS master or slave device. Based on its predicted travel path, cooperative network server 207 may query a centralized database to predict that vehicle 209 is approaching the boundary of the operating range 207 of radar 205. The centralized database may show that radar 205 is operating on a particular DFS channel. Cooperative network server 206 may send the GPS coordinates of one or more points on the boundary of the operating range 207, where it is predicted that vehicle 209 will enter the operating range 207 of radar 205 and the predicted operating channel of radar 205. If the WLAN device on vehicle 209 is operating on the same DFS channel, it may be prepared to switch to a different DFS channel before encountering radar interference from radar 205. In one embodiment, cooperative network server 206 may suggest a DFS channel for the WLAN device to switch to. Vehicle 209 can use this information to switch to a different DFS channel that causes minimal disruption to its WLAN operation.

[0030] In one embodiment, if a vehicle path has been selected, for example using an in-vehicle navigation system, the vehicle can query a centralized database to predict potential radar interference areas along the path. The WLAN device on the vehicle can select a DFS channel that is expected to cause minimal or no radar interference. Advantageously, the WLAN device can avoid interruptions to WLAN operations associated with channel switching, such as WLAN interruptions encountered when a WLAN DFS master performs a DFS-CAC scan on a new channel. The same applies to WLAN DFS slave devices; the ability to eliminate or reduce channel switching operations, or to switch channels before the vehicle approaches the expected radar area, reduces interruptions to WLAN operations and, in turn, reduces interference from WLAN operations to radar operations. In one embodiment, the WLAN device can prefetch or download the centralized database for offline use.

[0031] Figure 3 A local database of interference data from geotagged radar, according to some embodiments of this disclosure, is illustrated as an example system for assisting in the selection of WLAN DFS channels. In one embodiment, the locally stored database on the vehicle may contain information about radar interference collected solely by the vehicle. WLAN devices on the vehicle can query the local database using current or desired GPS coordinates to determine potential radar interference near the GPS coordinates based on location records already visited by the vehicle if radar interference is detected. While the locally stored database eliminates the need for WLAN devices to access a remote collaborative network server 206, it may not be as comprehensive or up-to-date as a crowdsourced database.

[0032] A vehicle 301, possibly equipped with an onboard WLAN DFS master device, may drive into the operating range 207 of radar 205 at location 302. If the WLAN DFS master device on vehicle 301 operates on the same DFS channel as radar 205, it can detect radar signals on the DFS channel via DFS-ISM scanning when vehicle 301 enters the operating radar range 207 at location 302. The WLAN DFS master device can record the DFS channel of radar 205, the GPS coordinates of vehicle 301 at location 302, and the time of radar interference detection in a local database of vehicle 301. The local database can be built by vehicle 301 over time to include a local knowledge base of radar areas with geotags and timestamps. Later, when vehicle 301 approaches the radar operating range 207 of radar 205 at location 303, the WLAN device can query the local database based on its current GPS coordinates at location 303 to receive a warning about nearby radar interference. If the WLAN device operates on the same DFS channel as radar 205, the WLAN device can be prepared to switch to a different channel before vehicle 301 encounters radar interference from radar 205. In one embodiment, a local database can suggest a DFS channel for the WLAN device to switch to. In another embodiment, if the path of vehicle 301 is known, the WLAN device can query the local database to predict potential radar interference areas and select a DFS channel that is expected to cause minimal or no radar interference.

[0033] In one embodiment, the locally stored database may be a crowdsourced database downloaded or prefetched by vehicle 301 from a collaborative network server (e.g., 206) for offline use. For example, a WLAN device on vehicle 301 may download the crowdsourced database to its locally stored database before the trip. Vehicle 301 can then utilize the crowdsourced information to identify potential sources of radar interference during the trip, even when the vehicle is offline. In one embodiment, the WLAN device may transmit a planned travel route to collaborative network server 206 and may download a portion of a crowdsourced database containing information about radar zones near the planned travel route to its locally stored database before or even during the trip. The WLAN device can then switch to offline mode to access the locally stored database. In one embodiment, the WLAN device of vehicle 301 may use peer-to-peer WLAN operations to download a locally stored database from another vehicle to its locally stored database to utilize information about radar interference collected by the other vehicle. In one embodiment, the WLAN device of vehicle 301 may download the database from another vehicle via peer-to-peer operations using LTE, 5G, or other types of cellular networks.

[0034] Figure 4A flowchart illustrating a method 400 of a WLAN device deployed in a vehicle, according to some embodiments of the present disclosure, for accessing a local database of interference data from a cooperative network server (e.g., 206) or geotagged radar as an aid in selecting a WLAN DFS channel. Method 400 can be executed by processing logic, which may include hardware (e.g., circuitry, dedicated logic, programmable logic, processing devices, etc.), software (e.g., instructions that run / execute on the processing device), firmware (e.g., microcode), or a combination thereof. In some embodiments, method 400 may be executed by a WLAN DFS master device or a processing device included in the WLAN device (e.g., Figure 5 The processing device 501 shown is used to execute this.

[0035] At position 401, a request is initiated to begin WLAN operation on a DFS channel. For example, a WLAN DFS master device in a vehicle may request operation on a DFS channel because only the DFS channel is available for WLAN operation in the geographic area, or because a scan of open channels indicates that non-DFS channels may not have sufficient bandwidth to support the required WLAN operation due to high data traffic or any other reason.

[0036] In one embodiment, the WLAN DFS master device may send its current location's GPS coordinates to a database, such as database 407 containing radar jamming data with timestamps and geotags, to receive information about candidate DFS channels for WLAN operation. Database 407 may be a centralized crowdsourced database of a collaborative network server (e.g., 206) or a database locally stored by the WLAN DFS master device. In one embodiment, the locally stored database may be built by the WLAN DFS master device over time to include information such as... Figure 3 The discussion focuses on a local knowledge base for radar areas with timestamps and geotags. In one embodiment, the locally stored database could be a crowdsourced database downloaded from a centralized database or prefetched by the WLAN DFS master device for offline use.

[0037] At 405, based on the current GPS location and current time of the WLAN DFS master device, database 407 can indicate to the WLAN DFS master device a DFS channel that can be used by radar operating near the current GPS location. In one embodiment, database 407 can suggest one or more DFS channels that can be used with minimal probability of radar interference.

[0038] At 403, method 400 can determine candidate DFS channels for WLAN operation. In one embodiment, if the WLAN DFS master receives information from database 407 about DFS channels used in a nearby radar zone, the WLAN DFS master can select a DFS channel that avoids potential radar interference. In another embodiment, if the WLAN DFS master receives recommendations from database 407 about DFS channels that minimize the probability of radar interference, the WLAN DFS master can select one of the recommended DFS channels.

[0039] At 409, method 400 may perform a DFS-CAC scan on the selected DFS channel. In one embodiment, regulations may require the WLAN DFS master to perform a DFS-CAC scan for a minimum time period to ensure that the channel is free from radar interference before the WLAN DFS master can begin operating in the selected DFS channel.

[0040] At 411, method 400 can determine whether a radar signal was detected during the DFS-CAC scan. For example, the WLAN DFS master device may be located in a position where database 407 may not contain any information or may not have up-to-date information on radar interference. Therefore, even if the information from database 407 does not indicate that the selected DFS channel is being used by a nearby radar, DFS-CAC can still detect radar interference on the selected DFS channel.

[0041] At 413, if a radar signal is detected on the selected DFS channel, method 400 can update database 407 with timestamped and geotagged entries containing information about the detected radar signal. For example, the WLAN DFS master device can record the DFS channel on which the radar signal was detected, the vehicle's GPS coordinates, and the time the radar signal was detected. The WLAN DFS master device can update database 407 with the recorded information about the DFS channel, the recorded GPS coordinates, and the recording time. In one embodiment, if database 407 is a centralized database, the WLAN DFS master device can upload information to a collaborative network server (e.g., 206) to update the crowdsourced database. The WLAN DFS master device can select new candidate DFS channels by querying database 407, and method 400 can be repeated at 403, 409, and 411 until a selected DFS channel without channel interference is found during the DFS-CAC scan.

[0042] At 415, if no radar signal is detected on the selected DFS channel, method 400 can initiate WLAN operation on the selected DFS channel. In parallel, method 400 can perform a DFS-ISM scan to monitor for any radar signals that may appear on the operation channel while the vehicle is moving. Method 400 can continuously query database 407 based on the vehicle's current GPS coordinates to determine whether the operation channel may encounter radar interference, for example, based on the vehicle's current location or its projected path.

[0043] At 417, if a radar signal is detected on the operating channel during a DFS-ISM scan, method 400 can update database 407 with an entry containing information about the detected radar signal, along with timestamps and geotags. For example, the WLAN DFS master device can record the DFS operating channel on which the radar signal was detected, the vehicle's GPS coordinates, and the time the radar signal was detected. The WLAN DFS master device can update database 407 with the recorded information about the DFS operating channel, the recorded GPS coordinates, and the recording time. The WLAN DFS master device can select a new candidate DFS channel for WLAN operation by querying database 407 in 403, and method 400 can repeat DFS-CAC and DFS-ISM scans in 409, 411, 415, and 417.

[0044] At 419, if no radar signal is detected on the operational channel during the DFS-ISM scan, method 400 can continue WLAN operation on the operational channel. Method 400 can continuously query database 407 based on the vehicle's current GPS coordinates to determine whether the operational channel is likely to encounter radar interference. For example, based on the projected path of the vehicle's travel, if radar interference is expected on the operational channel, the WLAN DFS master can switch to a different operational channel before radar interference occurs. The WLAN DFS master can select a new candidate DFS channel for WLAN operation by querying database 407 in 403, and method 400 can repeat the DFS-CAC and DFS-ISM scans in 409, 411, 415, and 417.

[0045] Although method 400 is illustrated using a WLAN DFS master device, a WLAN DFS slave device can also perform some steps of method 400 to access a cooperative network server (e.g., 206) or a local database containing timestamped, geotagged radar jamming data as an aid in selecting a WLAN DFS channel. For example, in 403, the slave device can determine candidate channels by receiving information from database 407 about DFS channels used in nearby radar zones or recommendations for DFS channels that minimize the probability of radar jamming. In 419, the slave device can select an operating channel and can continuously query database 407 based on the vehicle's current GPS coordinates to determine whether the operating channel is likely to encounter radar jamming. If radar jamming is anticipated on the operating channel, the slave device can switch to a different operating channel before radar jamming occurs.

[0046] Figure 5 This is a block diagram illustrating a WLAN DFS device 501 deployed in a vehicle according to some embodiments of this disclosure, configured to access a cooperative network server (e.g., 206) or local database for accessing geotagged radar interference data as an aid in selecting a WLAN DFS channel. The WLAN DFS device 501 may be a WLAN device on vehicles 201, 205, 209, 301, 303, and may implement the steps of method 400.

[0047] The WLAN DFS device 501 can be a WLAN DFS master device or a slave device. The WLAN DFS device 501 may include a GPS subsystem 503, a map service 505, a WLAN subsystem 507, a system clock 509, a wide area network (WAN) connection subsystem 511, a local storage subsystem 513, and a DFS channel selector application 515.

[0048] GPS subsystem 503 can be configured to provide GPS coordinates for WLAN DFS device 501. The GPS coordinates can be used to geotag detected radar signals targeting the WLAN DFS master device. Map service 505 can be configured to map the GPS coordinates provided by GPS subsystem 503 to driving paths and can also provide navigation services for the vehicle. The driving path can be used by a database of radar interference with geotags and timestamps to predict potential radar interference areas along the path.

[0049] The WLAN subsystem 507 can be configured to perform WLAN operation using a selected channel. For example, the WLAN subsystem 507 can be configured to send or receive data packets, control frames, etc., with other WLAN DFS devices or APs via the WLAN channel. The system clock 509 can be configured to track the system time used to timestamp radar signals detected by the WLAN DFS master device. In one embodiment, the GPS subsystem 503 can be configured to provide the system time.

[0050] The WAN connectivity subsystem 511 can be configured by the WLAN DFS master device to upload information about detected radar signals to a cooperating network server (e.g., 206), including the DFS channel of the detected radar signal, the recorded GPS coordinates, and the time the radar signal was recorded. The WAN connectivity subsystem 511 can also be configured by both the WLAN DFS master and slave devices to: send the current GPS coordinates of the WLAN DFS device 501 and receive information about radar interference near the current GPS coordinates from the cooperating network server (e.g., 206).

[0051] The local storage subsystem 513 can be configured to store a local database of radar jamming data with geotags and timestamps. In one embodiment, the local storage subsystem 513 may contain a local knowledge base of radar areas with geotags and timestamps detected by the WLAN DFS device 501. In another embodiment, the local storage subsystem 513 may store a crowdsourced centralized database of radar areas with geotags and timestamps downloaded from a collaborative network server (e.g., 206).

[0052] The DFS channel selector application 515 can run on the processor to execute. Figure 4 One or more operations in method 400 are performed so that WLAN DFS device 501 accesses a cooperative network server (e.g., 206) or local storage subsystem 513 to obtain radar jamming information with geotags and timestamps as an aid in selecting WLAN DFS channels for WLAN operation.

[0053] In one embodiment, the WLAN DFS device 501 may include memory and processing devices. The memory may be synchronous dynamic random access memory (DRAM), read-only memory (ROM), or other types of memory, configured to store the DFS channel selector application 515 or the local storage subsystem 513. The processing devices may be provided by one or more general-purpose processing devices (e.g., microprocessors, central processing units, etc.). In illustrative examples, the processing devices may include complex instruction set computing (CISC) microprocessors, reduced instruction set computing (RISC) microprocessors, very long instruction word (VLIW) microprocessors, or processors implementing other instruction sets, or processors implementing combinations of instruction sets. The processing devices may also include one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, etc. The processing devices may be configured to perform the operations described herein according to one or more aspects of this disclosure to perform the operations and steps discussed herein.

[0054] Figure 6 An example system is shown in which a car receives DFS action frames from a beacon device as an aid for selecting a WLAN DFS channel, according to some embodiments of the present disclosure.

[0055] Radar 205 operates on a WLAN DFS channel. Radar 205 may have an operating range 207. For example, radar 205 may be an air traffic radar operating at an airport. A dedicated WLAN beacon device, also referred to as WLAN DFS action frame beacon device 601 or 603, may be installed at the boundary of the operating radar range 207. The WLAN DFS action frame beacon device may broadcast special WLAN action frames, also referred to as DFS beacons, on the DFS channel of radar 205 to warn WLAN devices on vehicles approaching the operating radar range 207 that radar 205 is operating nearby and to avoid the DFS channel used by radar 205.

[0056] DFS beacons can carry information including a timestamp, one or more WLAN DFS channels used by radar 205 that should be avoided by the WLAN device, one or more recommended WLAN DFS channels that the WLAN device can use as alternative channels, information about the operational radar range 207, a digital signature, etc. In one embodiment, when beacon devices 601 / 603 recommend alternative channels, the WLAN DFS action frame beacon devices 601 / 603 can scan for traffic on cleared DFS channels not used by radar 205 to distribute WLAN traffic more evenly across the cleared DFS channels. In one embodiment, the WLAN DFS action frame beacon devices 601 / 603 can prioritize alternative channels, thus recommending channels with lower loads first. In one embodiment, information about the operational radar range 207 can be represented by GPS coordinates of the boundaries of the operational radar range 207. These GPS coordinates of the boundaries can define the valid area of ​​the information carried by the DFS beacon. In one embodiment, the WLAN device can use a digital signature to verify the authenticity or validity of the information carried by the DFS beacon. In one embodiment, DFS beacons can be sent periodically.

[0057] Because the WLAN DFS action frame beacon device 601 broadcasts a DFS beacon on the DFS channel used by radar 205, WLAN devices operating on the same DFS channel can receive the DFS beacon to quickly detect radar interference on the DFS channel and switch to another channel, such as one of the alternative channels recommended by the DFS beacon. In one embodiment, the WLAN DFS action frame beacon device 601 can broadcast the DFS beacon outside the operating radar range 207, so the transmission of the DFS beacon itself does not interfere with the operation of radar 205.

[0058] Advantageously, vehicles approaching the operational radar range 207 and whose WLAN devices operate on the DFS channel of radar 205 can detect DFS beacons and can switch their operating channels to cleared DFS channels before entering the operational radar range 207, thereby minimizing any interference to radar operation. Furthermore, since the DFS beacon is transmitted as a WLAN packet, both the WLAN DFS master and slave devices can detect the DFS beacon to quickly avoid DFS channels carrying radar signals.

[0059] For example, if a WLAN device operates on the same DFS channel as radar 205, a WLAN device on vehicle 605 approaching the operating radar range 207 from one direction can receive a DFS beacon from beacon device 601. The WLAN device can use the digital signature carried in the DFS beacon to authenticate the validity of the DFS beacon. The WLAN device can receive the valid area information carried by the DFS beacon, represented as the GPS coordinates of the boundary of the operating radar range 207. Based on this and the projected path of the vehicle, the WLAN device can determine that vehicle 605 can enter the operating radar range 207. The WLAN device can receive from the DFS beacon the DFS channels to be avoided and the recommended alternative DFS channels to migrate to. In one embodiment, the DFS channels to be avoided may include the WLAN device's current operating channel and other DFS channels that can be used by radar 205. Before vehicle 605 enters the operating radar range 207, the WLAN device can switch its operating channel to one of the recommended alternative DFS channels as the new channel. While the vehicle 605 is within the operating radar range 207, the WLAN device can continue WLAN operation using a new DFS channel without interfering with the operation of radar 205. When the vehicle 605 leaves the radar operating range 207, the WLAN device can remain on the new channel or switch back to its previous operating channel.

[0060] Similarly, if a WLAN device operates on the same DFS channel as radar 205, a WLAN device on another vehicle 609 approaching the operating radar range 207 from another direction can receive a DFS beacon from beacon device 603. Likewise, a WLAN device can switch to a new channel before vehicle 609 enters the operating radar range 207. The new channel used by the WLAN device on vehicle 609 can be the same as or different from the new channel used by the WLAN device on vehicle 605. Besides avoiding interference with the operation of radar 205, the new DFS channels used by vehicles 605, 609, and other vehicles 607, 611 for WLAN operation can be prioritized by beacon devices 601 / 603 to distribute the WLAN traffic load more evenly across the new DFS channels. Furthermore, even WLAN DFS slave devices that are normally unable to detect radar signals may be able to receive DFS beacons to switch to a new DFS channel to avoid interfering with the operation of radar 205.

[0061] Figure 7A flowchart illustrating a method 700 in which a WLAN device deployed in a vehicle receives a DFS beacon from a beacon device as an aid to selecting a WLAN DFS channel, according to some embodiments of the present disclosure, is shown. Method 700 can be executed by processing logic, which may include hardware (e.g., circuitry, dedicated logic, programmable logic, processor, processing device, central processing unit (CPU), multi-core processor, system-on-a-chip (SoC), etc.), software (e.g., instructions that run / execute on the processing device), firmware (e.g., microcode), or a combination thereof. In some embodiments, method 700 may be performed by a WLAN DFS master device, a WLAN DFS slave device, or a processing device included in the WLAN device (e.g., Figure 8B The processing device 811 shown is used to perform this.

[0062] At point 701, a WLAN device can operate in a DFS channel. For example, a WLAN DFS master or slave device in a vehicle can operate in a DFS channel because only the DFS channel is available for WLAN operation in the geographic area, or because scanning of open channels indicates that non-DFS channels may not have sufficient bandwidth to support the required WLAN operation due to high data traffic or any other reason. In one embodiment, the WLAN device may have performed a DFS-CAC scan to confirm that no radar is operating in that DFS channel before commencing operation in that channel.

[0063] At point 703, the WLAN device can monitor DFS beacons on the DFS channel to detect alarms for radars operating on the same DFS channel. In parallel, the WLAN device can perform a DFS-ISM scan to detect any radar signals that may appear on the operational channel. For example, in addition to monitoring DFS beacons, the WLAN DFS master device can also perform a DFS-ISM scan on the operational channel. For a WLAN DFS slave device that does not have the capability to detect radar signals, in addition to monitoring DFS beacons, it can also monitor the operational channel to detect messages from the associated WLAN DFS master device indicating that the WLAN DFS master device has detected a radar signature.

[0064] At 705, the WLAN DFS master device can determine whether a radar signal is detected on the operational channel via a DFS-ISM scan. At 711, if a radar signal is detected on the operational channel, the WLAN DFS master device can determine a candidate channel to switch to, and if that channel is a DFS channel, a DFS-CAC scan can be performed. The WLAN DFS master device can repeat this process across the entire list of candidate channels until it finds a candidate channel without radar operation. In one embodiment, the WLAN DFS master device can send a message on the operational channel to the associated slave device to signal a switch to the operational channel. If the slave device is currently using the operational channel, the slave device receiving the message can determine a candidate channel to switch to.

[0065] At point 713, the WLAN device can determine whether the candidate channel is a DFS channel. If the candidate channel is a DFS channel, then at point 703, the WLAN device can switch to the candidate channel as the new WLAN operating channel and can monitor DFS beacons on the new channel to detect alarms for radars operating on the new channel. In parallel, if the WLAN device is a WLAN DFS master, it can perform a DFS-ISM scan to monitor for any radar signals that may appear on the new channel. If the candidate channel is not a DFS channel, then at point 715, the WLAN device can switch to the candidate channel for WLAN operation.

[0066] At point 707, if the WLAN DFS master device does not detect a radar signal on the operational channel via DFS-ISM scanning, or if the WLAN DFS slave device does not receive a message from its associated WLAN DFS master device indicating that the radar beacon has been detected by the WLAN DFS master device, the WLAN device can determine whether it has received a DFS beacon on the operational channel.

[0067] If no DFS beacon is received on the operational channel, at point 703, the WLAN device can continue monitoring the operational channel for DFS beacons to detect alarms for radars operating on the operational channel. In parallel, if the WLAN device is a WLAN DFS master, or if the WLAN device is a slave, the WLAN device can continue performing a DFS-ISM scan to monitor for any radar signals that may be present on the operational channel, in order to continue monitoring the operational channel for messages from the associated WLAN DFS master indicating that a radar marker has been detected.

[0068] If a DFS beacon has been received on the operational channel, at 709, the WLAN device can use the digital signature carried in the DFS beacon to verify its validity. If the DFS beacon is authenticated, at 710, the WLAN device can receive information about the valid area of ​​the DFS beacon, which can indicate the area of ​​radar operation. Based on this information and the projected path of the vehicle, the WLAN device can determine that the vehicle may have entered the radar operational area. The WLAN device can receive the DFS channel from the DFS beacon to avoid this, which may include the current operational channel as well as recommended alternative DFS channels to migrate to. At 711, before the vehicle enters the radar operational area, the WLAN device can switch to one of the recommended alternative DFS channels as the new channel for WLAN operation. Then, at 713, the WLAN device can determine whether the new channel is a DFS channel. If the new channel is a DFS channel, at 703, the WLAN device can monitor the DFS beacon on the new channel to detect alarms for radar operating on the new channel. In parallel, if the WLAN device is a WLAN DFS master, it can perform a DFS-ISM scan to monitor for any radar signals that may appear on the new channel. If the new channel is not a DFS channel, the WLAN device can use the new channel for operation at 715.

[0069] Figure 8A This is a block diagram of a DFS action frame beacon device 801 according to some embodiments of the present disclosure. The beacon device 801 may be... Figure 6 The beacon equipment 601 or 603.

[0070] DFS action frame beacon device 801 may include a DFS action frame triggering application 803, a WLAN driver 805, and WLAN hardware 807. The DFS action frame triggering application 803 may run on a processor to periodically generate DFS beacon information, including timestamps, one or more WLAN DFS channels used by nearby radars, one or more recommended WLAN DFS channels that WLAN devices can use as alternative channels, information about the radar's operating range, digital signatures, etc. In one embodiment, the DFS action frame triggering application 803 may use the WLAN hardware 807 to scan for traffic on cleared DFS channels not used by radars when recommending alternative channels, so that WLAN traffic from WLAN devices is more evenly distributed across the cleared DFS channels.

[0071] The WLAN driver 805 can run on the processor to generate WLAN packets with a payload carrying DFS beacon information provided by the DFS action frame triggering application 803. The WLAN hardware 807 can be configured to periodically transmit WLAN packets as DFS action frames or DFS beacons on the DFS channel used by the radar.

[0072] Figure 8B This is a block diagram illustrating a WLAN DFS device 811 deployed in a vehicle according to some embodiments of the present disclosure, configured to receive DFS action frames from beacon devices (e.g., 601, 603, 801) as an aid for selecting a WLAN DFS channel. The WLAN DFS device 811 can be a WLAN DFS master or slave device. The WLAN DFS device 811 can be a WLAN device on vehicles 605, 607, 609, 611, and can practice the steps of method 700.

[0073] The WLAN DFS device 811 may include WLAN hardware 813 and a WLAN driver 815. The WLAN driver 815 may include a WLAN Tx / RX controller 817, conventional WLAN DFS logic 819, and DFS action frame monitoring logic 821. The WLAN hardware may be configured to transmit or receive WLAN packets on an operational channel, including receiving DFS beacons from the DFS action frame beacon device 801.

[0074] The WLAN Tx / Rx controller 817 can be configured to demodulate and decode received WLAN packets, and to encode and modulate WLAN packets for transmission. The DFS action frame monitoring logic 821 can be configured to detect DFS beacons. When a DFS beacon is received, the DFS action frame monitoring logic 821 can use the digital signature carried in the DFS beacon to authenticate the validity of the DFS beacon. Once the DFS beacon is authenticated, the DFS action frame monitoring logic 821 can obtain information about one or more WLAN DFS channels used by nearby radars, one or more recommended WLAN DFS channels that the WLAN DFS device 811 can use as alternative channels, information about the radar's operating range, and so on.

[0075] If the current operating channel is used by a nearby radar, the conventional WLAN DFS logic 819 can be configured to switch to one of the recommended WLAN DFS channels obtained from the DFS beacon or a non-DFS channel, if available. In one embodiment, if the WLAN DFS device 811 is a WLAN DFS master and if a radar signal is detected on the operating channel via DFS-CAC or DFS-ISM scanning, the conventional WLAN DFS logic 819 can be configured to generate a message, which will be sent on the current operating channel, to signal to the associated slave device a switch from the current operating channel. In one embodiment, if the WLAN DFS device 811 is a WLAN DFS slave and if it receives a message from the associated WLAN DFS master to switch its current operating channel, the conventional WLAN DFS logic 819 can be configured to select a new channel for WLAN operation.

[0076] In one embodiment, the DFS action frame beacon device 801 or the WLAN DFS device 811 may include memory and processing devices. The memory may be synchronous dynamic random access memory (DRAM), read-only memory (ROM), or other types of memory configured to store code for performing the functions of the WLAN driver 813 or 815. The processing devices may be provided by one or more general-purpose processing devices (e.g., microprocessors, central processing units, etc.). In illustrative examples, the processing devices may include complex instruction set computing (CISC) microprocessors, reduced instruction set computing (RISC) microprocessors, very long instruction word (VLIW) microprocessors, or processors implementing other instruction sets, or processors implementing combinations of instruction sets. The processing devices may also include one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, etc. The processing devices may be configured to perform the operations described herein according to one or more aspects of this disclosure to perform the operations and steps discussed herein.

[0077] Unless otherwise stated, terms such as “receive,” “generate,” “verify,” “execute,” “correct,” and “identify” refer to actions and processes performed or implemented by a computing device that operate and convert data represented as physical (electronic) quantities in the registers and memory of the computing device into other data similarly represented as physical quantities in the memory or registers of the computing device or other such information storage, transmission, or display devices.

[0078] The examples described herein also relate to apparatus for performing the operations described herein. Such apparatus may be specifically constructed for a desired purpose, or it may comprise a general-purpose computing device selectively programmed by a computer program stored in a computing device. Such a computer program may be stored in a computer-readable, non-transitory storage medium.

[0079] Some embodiments can be implemented as a computer program product that may include instructions stored on a machine-readable medium. These instructions can be used to program a general-purpose or special-purpose processor to perform the described operations. A machine-readable medium includes any mechanism for storing or transmitting information in a machine-readable form (e.g., software, processing application). Machine-readable media may include, but are not limited to, magnetic storage media (e.g., floppy disks); optical storage media (e.g., CD-ROMs); magneto-optical storage media; read-only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM and EEPROM); flash memory; or another medium suitable for storing electronic instructions. A machine-readable medium may be referred to as a non-transitory machine-readable medium.

[0080] The methods and illustrative examples described herein are not inherently related to any particular computer or other device. It may prove convenient to use various general-purpose systems based on the teachings described herein, or to construct more specialized devices to perform the required method steps. The necessary structures for various such systems will emerge as illustrated in the description above.

[0081] The above description is intended to be illustrative and not restrictive. Although this disclosure has been described with reference to specific illustrative examples, it should be understood that this disclosure is not limited to the described examples. The full scope of this disclosure, together with the equivalents of these claims, should be determined by referring to the appended claims.

[0082] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that, when used herein, the terms “comprises,” “comprising,” “includes,” and / or “including” designate the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, the terms “first,” “second,” “third,” “fourth,” etc., as used herein are intended as labels to distinguish different elements, and their numerical designation may not necessarily have an ordering meaning. Therefore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be restrictive.

[0083] It should also be noted that in some alternative implementations, the labeled functions / actions may not occur in the order shown in the figures. For example, two figures shown as successive may actually be executed substantially in parallel, or sometimes in reverse order, depending on the functions / actions involved.

[0084] Although the method operations are described in a specific order, it should be understood that other operations may be performed between the described operations, the described operations may be adjusted to occur at slightly different times, or the described operations may be distributed in a system to allow processing operations to occur at various intervals associated with the processing.

[0085] Various units, circuits, or other components may be described or claimed to be "configured to" or "configurable to" perform a task or tasks. In such a context, the phrase "configured to" or "configurable to" is used to imply a structure by indicating that the unit / circuit / component includes a structure (e.g., a circuit) that performs a task or tasks during operation. Thus, even if the specified unit / circuit / component is not currently running (e.g., not turned on), it can be said that the unit / circuit / component is configured to perform a task, or is configurable to perform a task. Units / circuits used with the language "configured to" or "configurable to" include hardware—e.g., circuits, memory storing program instructions that can be executed to perform operations, etc. When referring to a unit / circuit / component as "configured to" or "configurable to" perform one or more tasks, it is explicitly intended that 35 U.S.SC112, paragraph 6, not be invoked against that unit / circuit / component. Furthermore, "configured as" or "configurable as" can include a general-purpose structure (e.g., a general-purpose circuit) manipulated by software and / or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in a manner capable of performing relevant tasks. "Configured as" can also include: adapting a manufacturing process (e.g., a semiconductor manufacturing facility) to manufacture a device (e.g., an integrated circuit) suitable for implementing or performing one or more tasks. Unless accompanied by a programming medium that endows an unprogrammed device with the ability to perform the disclosed functions, "configurable as" expressly indicates that it is not applicable to blank media, unprogrammed processors or unprogrammed general-purpose computers, or unprogrammed programmable logic devices, programmable gate arrays, or other unprogrammed devices.

[0086] For illustrative purposes, the foregoing description has been described with reference to specific embodiments. However, the above illustrative discussion is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the foregoing teachings. These embodiments were chosen and described in order to best explain the principles of these embodiments and their practical application, thereby enabling others skilled in the art to best utilize these embodiments and various modifications that may be suitable for the particular uses contemplated. Therefore, the given embodiments are to be considered illustrative rather than restrictive, and the invention is not limited to the details set forth herein but can be modified within the scope and equivalents of the appended claims.

Claims

1. A method for operating a wireless local area network (WLAN) device, comprising: The WLAN device operates on the first DFS channel among multiple dynamically selected DFS channels; The WLAN device scans the first DFS channel to detect the presence of radar signals from the radar. The auxiliary information received by the WLAN device is obtained by one or more WLAN devices capable of scanning the DFS channel, wherein the auxiliary information indicates whether the first DFS channel is used by the radar, and wherein the auxiliary information received by the WLAN device includes broadcast WLAN action frames received from a second WLAN device through the first DFS channel; Identify the digital signature included in the broadcast WLAN action frame; The auxiliary information is authenticated using the digital signature. In response to authenticating the auxiliary information, the system determines, based on the auxiliary information, that the WLAN device is approaching the radar interference range of the radar; and In response to the following, the operation of the WLAN device will be changed from using the first DFS channel to using the second DFS channel among the plurality of DFS channels: authenticating the auxiliary information and the auxiliary information indicating that the first DFS channel is being used by the radar.

2. The method according to claim 1, wherein, Receiving the assistance information via the WLAN device includes receiving the assistance information from a crowdsourcing database via a cellular network, wherein the crowdsourcing database contains multiple geotagged radar zones detected by multiple WLAN devices capable of scanning the DFS channel.

3. The method according to claim 2, wherein, One of the plurality of geotagged radar zones includes a geographic area in which the operational radar is detected by one of the plurality of WLAN devices capable of scanning the DFS channels, and one or more of the plurality of DFS channels are detected as being used by the operational radar in the geographic area.

4. The method of claim 3, further comprising sending the geographical location of the WLAN device to the crowdsourcing database, wherein, The received auxiliary information includes a received geotagged radar area from among the plurality of geotagged radar areas, wherein the geographical area of ​​the received geotagged radar area indicates that the operating radar is near the geographical location of the WLAN device.

5. The method according to claim 3, wherein, The received auxiliary information indicating that the first DFS channel is being used by the radar includes information indicating that the first DFS channel overlaps with one or more DFS channels that are detected being used by the operational radar at one of the plurality of geotagged radar zones.

6. The method according to claim 1, wherein, The auxiliary information is received from a locally stored database, which contains multiple geotagged radar zones previously detected by the WLAN device.

7. The method according to claim 1, wherein, The broadcast WLAN action frame carries information about one or more DFS channels currently being used by the radar, and one or more alternative DFS channels that can be used for WLAN operation.

8. The method according to claim 7, wherein, The received auxiliary information indicating that the first DFS channel is being used by the radar includes information indicating that the first DFS channel overlaps with one or more DFS channels being used by the radar, and wherein the second DFS channel is selected from one of the one or more alternative DFS channels.

9. The method according to claim 1, wherein, The scanning of the first DFS channel by the WLAN device to detect the presence of the radar signal includes receiving a message from the second WLAN device, wherein the message indicates that the second WLAN device has detected the presence of the radar signal on the first DFS channel.

10. A wireless local area network (WLAN) device, comprising: A WLAN interface configured to operate the WLAN device on a first DFS channel among a plurality of dynamically selected DFS channels; as well as The processing equipment is configured as follows: Scan the first DFS channel to detect the presence of radar signals from the radar; Receive auxiliary information obtained by one or more WLAN devices capable of scanning the DFS channel, wherein the auxiliary information indicates whether the first DFS channel is used by the radar, and wherein the auxiliary information received by the WLAN device includes broadcast WLAN action frames received from a second WLAN device via the first DFS channel; Identify the digital signature included in the broadcast WLAN action frame; The auxiliary information is authenticated using the digital signature. In response to authenticating the auxiliary information, the system determines, based on the auxiliary information, that the WLAN device is approaching the radar interference range of the radar; and In response to the following, the first DFS channel used for WLAN operation is switched to the second DFS channel among the plurality of DFS channels: authentication of the auxiliary information and the auxiliary information indicating that the first DFS channel is being used by the radar.

11. The WLAN device according to claim 10, wherein, The auxiliary information is received from a crowdsourcing database via a cellular network, wherein the crowdsourcing database contains multiple geotagged radar zones detected by multiple WLAN devices capable of scanning the DFS channel.

12. The WLAN device according to claim 11, wherein, One of the plurality of geotagged radar zones includes a geographic area in which the operational radar is detected by one of the plurality of WLAN devices capable of scanning the DFS channels, and one or more of the plurality of DFS channels are detected as being used by the operational radar in the geographic area.

13. The WLAN device according to claim 12, wherein, The processing device is further configured to send the geographic location of the WLAN device to the crowdsourcing database, wherein the received auxiliary information includes a received geographic-tagged radar area from the plurality of geographic-tagged radar areas, wherein the geographic area of ​​the received geographic-tagged radar area indicates that the operating radar is near the geographic location of the WLAN device.

14. The WLAN device according to claim 12, wherein, The received auxiliary information indicating that the first DFS channel is being used by the radar includes information indicating that the first DFS channel overlaps with one or more DFS channels that are detected being used by the operational radar at one of the plurality of geotagged radar zones.

15. The WLAN device according to claim 10, wherein, The auxiliary information is received from a locally stored database of the WLAN device, wherein the locally stored database contains multiple geotagged radar zones previously detected by the WLAN device.

16. The WLAN device according to claim 10, wherein, The broadcast WLAN action frame carries information about one or more DFS channels used by the radar and one or more alternative DFS channels that can be used for the WLAN operation.

17. The WLAN device according to claim 16, wherein, The received auxiliary information indicating that the first DFS channel is being used by the radar includes information indicating that the first DFS channel overlaps with one or more DFS channels used by the radar among the plurality of DFS channels, and wherein the second DFS channel is selected from one of the one or more alternative DFS channels.

18. The WLAN device according to claim 10, wherein, The processing device is configured to scan the first DFS channel to detect the presence of the radar signal, including: the processing device is further configured to receive a message from a second WLAN device, wherein the message indicates that the second WLAN device has detected the presence of the radar signal on the first DFS channel.

19. A communication device, comprising: The processing equipment is configured as follows: Information about a geotagged radar area is generated, the geotagged radar area including the geographic area in which the operating radar operates, and one or more Dynamic Frequency Selection (DFS) channels are used by the operating radar in the geographic area; as well as Broadcasting a WLAN action frame via the first DFS channel, the WLAN action frame causes WLAN devices approaching the geotagged radar area to: The WLAN action frame is authenticated using a digital signature included in the WLAN action frame; as well as In response to authenticating the WLAN action frame, the DFS channel used by the operational radar is bypassed.

20. The communication device according to claim 19, wherein, The processing device is further configured to: Scanning traffic on one or more cleared DFS channels not used by the operational radar; and The WLAN action frame is used to broadcast information about the cleared DFS channel, so that the WLAN device switches from using the DFS channel used by the operational radar to the cleared DFS channel.

Images