Dynamic frequency selection method and related apparatus

Abstract

A communication apparatus is provided, including a first device, a second device, and a control circuit. The first device is used to establish a wireless link with a wireless communication device in a first communication channel. The second device is used to perform a first scan of a second communication channel for a predetermined duration to detect whether there are any radar signals on the second communication channel. In response to the first scan meeting a predetermined condition, the control circuit controls the first device to move the wireless link from the first communication channel to the second communication channel. Using this method, the wireless link can be moved to the second communication channel.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and more particularly to a zero-waiting dynamic frequency selection (DFS) method and an apparatus using the method. Background Technology

[0002] Wi-Fi networks are widely used in today's portable devices. IEEE 802.11 networks operate in the 5 GHz and 2.4 GHz bands. The 5 GHz band has 23 orthogonal channels, while the 2.4 GHz band has only 3. The 5 GHz band is not very crowded and has little interference. However, some radar technologies (such as military radar, satellite communications, and weather radar) use the 5 GHz band. Wi-Fi devices operating in the 5 GHz band must perform a channel allocation scheme called "dynamic frequency selection (DFS)" to avoid conflicts with these radar technologies. The actual mechanism, duration, radar pulse pattern, power level, and frequency band for implementing DFS may vary by country and jurisdiction.

[0003] Before transmitting on a target DFS channel, an IEEE 802.11 Wi-Fi station must verify the absence of radar activity by listening for radar activity on the target DFS channel for at least 60 seconds. However, users of DFS-enabled Wi-Fi stations find the time required for this DFS scan inconvenient. Summary of the Invention

[0004] This invention provides a communication device. The device includes a first device, a second device, and a control circuit. The first device is used to establish a wireless link with a wireless communication device in a first communication channel. The second device is used to perform a first scan of a second communication channel for a predetermined period of time to detect the presence of any radar signals on the second communication channel. In response to the first scan satisfying a predetermined condition, the control circuit controls the first device to move the wireless link from the first communication channel to the second communication channel.

[0005] Another embodiment of the present invention provides a wireless communication method (channel selection method) for an apparatus including a first device and a second device. The method includes the following steps: establishing a wireless link with a wireless communication device in a first communication channel using the first device; performing a first scan of a second communication channel for a first predetermined duration using the second device to detect whether a radar signal is present on the second communication channel; and controlling the first device to move the wireless link from the first communication channel to the second communication channel in response to the first scan satisfying a predetermined condition.

[0006] Another embodiment of the present invention provides a communication device. The device includes one or more antennas and circuitry. The circuitry is used to establish a wireless link with a wireless communication device in a first communication channel via the one or more antennas. The first communication channel has a first frequency band, and the wireless link has a second frequency band within the first frequency band. In response to no radar signal being detected during a scan of a third frequency band (excluding the second frequency band) within the first frequency band for a predetermined duration, the circuitry extends the wireless link using the first frequency band.

[0007] Another embodiment of the present invention provides a wireless communication method (bandwidth extension method), the method comprising: establishing a wireless link with a wireless communication device in a first communication channel, wherein the first communication channel has a first frequency band and the wireless link has a second frequency band within the first frequency band, and extending the bandwidth of the wireless link to the first frequency band in response to the absence of a radar signal detected by performing a scan of a third frequency band within the first frequency band other than the second frequency band for a predetermined duration. Attached Figure Description

[0008] The invention can be more fully understood by referring to the following detailed description and embodiments, in which:

[0009] Figure 1 A portion of the 5GHz Wi-Fi spectrum 100 is shown, including the portion requiring active monitoring of radar signals;

[0010] Figure 2 This is a schematic diagram of a wireless communication device according to an embodiment of the present invention.

[0011] Figure 3A The frequency band of the operating channel used by the wireless communication device according to an embodiment of the present invention before performing a CAC scan is shown.

[0012] Figure 3B Showing according to Figure 3A The embodiment describes the frequency band of the operating channel used by the wireless communication device after CAC scanning.

[0013] Figure 4 This is a schematic diagram of a wireless communication device according to another embodiment of the present invention.

[0014] Figure 5A Showing according to Figure 4 The embodiment refers to the channel used by the wireless communication device before CAC scanning.

[0015] Figure 5B Showing according to Figure 5A The embodiment describes the operating channel that is changed by the wireless communication device after CAC scanning.

[0016] Figure 6A It shows that according to Figure 4 The embodiment refers to the channel used by the wireless communication device prior to CAC scanning.

[0017] Figure 6B Showing according to Figure 6A In this embodiment, the wireless communication device changes its operating channel after the first CAC scan.

[0018] Figure 6C Showing according to Figure 6B The embodiment changes the bandwidth of the wireless link after the second CAC scan.

[0019] Figure 7 This is a flowchart of a zero-wait dynamic frequency selection method according to an embodiment of the present invention. Detailed Implementation

[0020] The following description is for illustrating the general principles of the invention and should not be construed as limiting. The scope of the invention is best determined by referring to the appended claims.

[0021] The following description is provided to enable those skilled in the art to make and use the invention, and is offered in the context of patent applications and their requirements. Various modifications to the embodiments and general principles and features described herein will be apparent to those skilled in the art. Therefore, the invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.

[0022] Figure 1 This shows a portion of the 5GHz Wi-Fi spectrum 100, including the portion requiring active radar signal monitoring. (For example...) Figure 1As shown, frequency 1001 and channel 1002 constitute part of the 5GHz Wi-Fi spectrum 100. The U-NII band is a regulatory domain defined by the Federal Communications Commission (FCC) for 5GHz wireless devices. It is a portion of the radio frequency spectrum used by IEEE 802.11ac / n devices and some wireless Internet Service Providers (ISPs), operating in four ranges: U-NII-1 band 101, U-NII-2 band 102, U-NII-3 band 103, and U-NII-4 band 104. For example, U-NII-1 band 101 covers the 5.15–5.25 GHz range, including channels 36 to 48. U-NII-2A band 102 covers the 5.25–5.35 GHz range, including channels 52 to 64. U-NII-2A band 102 is subject to DFS radar detection and avoidance requirements. U-NII-2C band 103 covers the 5.47–5.725 GHz range, including channels 100 to 140. U-NII-2C band 103 is also subject to DFS radar detection and avoidance requirements. U-NII-3 band 104 covers the 5.725–5.850 GHz range, including channels 149 to 165. Use of U-NII-3 band 104 is restricted in some jurisdictions, such as the EU and Japan. Accordingly, Figure 1 The 5GHz Wi-Fi spectrum 100 shown may include DFS bands and non-DFS bands, which may vary by country depending on local DFS rules.

[0023] Figure 2 This is a schematic diagram of a wireless communication device according to an embodiment of the present invention.

[0024] like Figure 2As shown, the wireless communication device 200 may include one or more antennas 210, an integrated circuit 220, a processor 230, and a memory 240. The antenna 210 can transmit and receive radio frequency (RF) signals. The integrated circuit 220 is coupled to the antenna 210 and may include one or more transceivers 221. The transceiver 221 can receive RF signals from the antenna 210, convert them into baseband signals, and transmit the baseband signals to the processor 230. The transceiver 221 can also convert the baseband signals from the processor 230 into RF signals and transmit the RF signals to the antenna 210. In some embodiments, the integrated circuit 220 may support SU-MIMO (single-user multi-input multi-output) and MU-MIMO (multi-user multi-input multi-output) functions, but the invention is not limited thereto.

[0025] Processor 230 may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), or a microcontroller, but the present invention is not limited thereto. In some embodiments, integrated circuit 220 may be a Wi-Fi chip, and integrated circuit 220 and processor 230 may be implemented by a system-on-chip (SoC), but the present invention is not limited thereto. Memory 240 may be volatile memory or non-volatile memory. For example, volatile memory may be static random access memory (SRAM) or dynamic random access memory (DRAM), and non-volatile memory may be flash memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM), but the present invention is not limited thereto. In addition, the memory 240 may store instructions or firmware executed by the processor 230 to control the operation of the wireless communication device 200.

[0026] Figure 3AThe frequency band of the operating channel used by the wireless communication device prior to CAC scanning is shown according to an embodiment of the present invention. Figure 3B Showing according to Figure 3A The embodiment describes the frequency band of the operating channel used by the wireless communication device after CAC scanning.

[0027] Please refer to Figure 2 and Figures 3A-3B In this embodiment, the wireless communication device 200 may be a DFS master, capable of actively scanning DFS channels, performing channel availability checks (CAC), and then performing periodic in-service monitoring (ISM) after the CAC. Furthermore, it is assumed that the wireless communication device 200 is capable of data transmission with another wireless communication device (e.g., an access point, site, etc.) on its supported frequency band 300, which has the maximum bandwidth supported by the wireless communication device 200. Figure 3A In the scenario shown, wireless communication device 200 can transmit data to another wireless communication device via a wireless link 310 established on a non-DFS frequency band 301 of the operating channel. The operating channel 320 includes a non-DFS frequency band 301 and a DFS frequency band 302, wherein the non-DFS frequency band 301 has a first bandwidth and the DFS frequency band 302 has a second bandwidth. It should be noted that, for ease of description, Figure 3A The non-DFS band 301 and DFS band 302 shown are continuous in the 5 GHz spectrum. In some cases, Figure 3A The non-DFS band 301 and DFS band 302 may be discontinuous in the 5 GHz spectrum. In some embodiments, the bandwidth of the operating channel 320 may be 20 MHz, 40 MHz, 80 MHz, etc., but the present invention is not limited thereto.

[0028] Meanwhile, since the wireless communication device 200 lacks information about channels in the DFS band 302 where no radar signals are present, it performs a CAC scan on the DFS band 302 for 60 seconds. After the 60-second CAC scan, the wireless communication device 200 detects that no radar signals appear in the DFS band 302. The wireless communication device 200 can then extend the bandwidth of the wireless link 310 to use both the non-DFS band 301 and the DFS band 302 for data transmission; that is, the overall bandwidth of the wireless link 310 used for data transmission can be significantly increased.

[0029] Figure 4 This is a schematic diagram of a wireless communication device according to another embodiment of the present invention.

[0030] In another embodiment, the wireless communication device 400 may include a first device 410, a second device 420, and a control circuit 430. Each of the first device 410 and the second device 420 may be a separate wireless communication device for transmitting and receiving RF signals, such as... Figure 2 The wireless communication device 200 is shown. Furthermore, the transmission and reception of RF signals by the first device 410 and the second device 420 are coordinated by a control circuit 430, which may be implemented by a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), or a microcontroller, but the invention is not limited thereto.

[0031] In some embodiments, the first device 410 and the second device 420 may be DFS master devices capable of performing CAC scanning on channels in the DFS band. In some embodiments, the performance or hardware resources of the first device 410 may be higher than those of the second device 420. For example, the first device 410 may be the master device for data transmission and reception, thus requiring higher performance and hardware. The second device 420 may be used to perform CAC scanning while the first device 410 is using a specific channel (e.g., channel A) to transmit data to or receive data from other wireless communication devices; therefore, the second device 420 may be implemented using hardware with lower computing power.

[0032] Figure 5A It shows that according to Figure 4 The embodiment refers to the channel used by the wireless communication device before CAC scanning. Figure 5B Showing according to Figure 5A In one embodiment, the wireless communication device changes its operating channel after a CAC scan.

[0033] Please refer to Figure 4 and Figures 5A-5B .exist Figure 5A In the scenario shown, there are multiple channels in spectrum 500. Assume the first device 410 operates in channel A, that is, it sends data to and receives data from other wireless communication devices via the wireless link 510 in channel A. Channel A may be in a non-DFS band or a DFS band. Simultaneously, the control circuit 430 can control the second device 420 to select a target DFS channel (e.g., channel B) from DFS channels other than channel A, and periodically detect whether there is a radar signal in the target DFS channel for 60 seconds (i.e., CAC scanning). Figure 5A As shown.

[0034] If no radar signal is detected on the target DFS channel (e.g., channel B) after a 60-second scan, the second device 420 can notify the control circuit 430 that the target DFS channel (e.g., channel B) is available. If any radar signal is detected on the target DFS channel (e.g., channel B) during a 60-second (or longer) scan, the second device 420 can add the target DFS channel (e.g., channel B) to a blacklist for 30 minutes, meaning that the target DFS channel will not be detected or used for 30 minutes according to the blacklist. Afterward, the second device 420 can select another target DFS channel (e.g., channel C) and scan the selected target DFS channel for 60 seconds to determine if there is a radar signal on the selected target DFS channel. If any radar signal is detected on the selected target DFS channel, the above operation can be repeated.

[0035] It is important to note that when the first device 410 is operating in channel A, it can also continuously monitor the presence of radar signals in channel A, which can be considered "in-service monitoring". Specifically, assuming the first device 410 is operating in channel A and the second device 420 detects that channel B (a non-operational channel) is available via a 60-second CAC scan, when the first device 410 detects radar signals in channel A or when the first device 410 determines that channel A is busy, the first device 410 can move the wireless link 510 used for data transmission and reception from channel A to channel B.

[0036] For example, when the first device 410 detects a radar signal in the operating channel or determines that the operating channel is busy, the first device 410 will stop transmitting on the current operating channel and wait for the detection result from the second device. When the second device's detection result after a predetermined scanning period ends and the second device determines that a new channel is available, the first device 410 moves to the new channel. Assuming that the wireless communication device 400 is an access point and is connected to one or more client devices, before moving channels, the first device 410 of the wireless communication device 400 can send a "channel switch announcement" frame as defined in the IEEE 802.11 specification to the connected client devices to inform them which channel the wireless communication device 400 will move to. In some embodiments, when a radar signal is detected in the current operating channel of the first device 410, the second device 420 can select one of the available non-DFS channels as the target channel to move to, or select a fixed channel as the target channel to move to, but the invention is not limited to these.

[0037] After the first device 410 has successfully moved the operating channel from channel A to channel B, the second device 420 can select a new target DFS channel (e.g., channel C) and periodically detect whether there are any radar signals on the new target DFS channel for 60 seconds (i.e., CAC scan).

[0038] Therefore, from the perspective of the wireless communication device 400, because the second device 420 can detect the available target DFS channel in advance (i.e., no radar signal is detected), the wireless link 510 used by the wireless communication device 400 can quickly and seamlessly change from channel A to channel B. Thus, the user of the wireless communication device 400 will not perceive any delay in changing the operating channel, thereby achieving "zero-wait DFS" and improving the user experience.

[0039] Figure 6A It shows that according to Figure 4 The embodiment refers to the channel used by the wireless communication device before CAC scanning. Figure 6B It shows that according to Figure 6A In one embodiment, the wireless communication device changes its operating channel after the first CAC scan. Figure 6C It shows that according to Figure 6B In this embodiment, the wireless communication device changes the bandwidth of the wireless link after the second CAC scan.

[0040] Please refer to Figure 4 and Figures 6A-6C .exist Figure 6A In the scenario shown, there are multiple channels in spectrum 600 (e.g., channels A to C, etc.). Assume the first device 410 operates on channel A, i.e., it transmits data to and receives data from other wireless communication devices via the wireless link 610 in channel A. Channel A can be in a non-DFS band or a DFS band. Simultaneously, the control circuit 430 can control the second device 420 to select a target DFS channel (e.g., channel B) from DFS channels other than channel A, and periodically detect whether there are any radar signals in the selected portion (i.e., frequency band 602) of the target DFS channel for 60 seconds (i.e., CAC scan). Figure 6AAs shown. Furthermore, the first device 410 can operate in a given channel with a larger bandwidth (i.e., band 601 of channel A), while the second device 420 detects whether there are any radar signals in a selected portion of the target DFS channel (i.e., band 602 of channel B). For example, for ease of description, the first device 410 can operate in channel A with a full bandwidth of 40 MHz, while the second device 420 can detect whether there are any radar signals in a selected portion of the target DFS channel, where the selected portion may have a limited bandwidth of 20 MHz due to the limited hardware provided in the second device 420. However, the invention is not limited to the bandwidth of the operating channel and the selected portion described above. It should be noted that the selected portion of channel B can be located anywhere within the entire band of channel B (i.e., band 603).

[0041] If no radar signal is detected on a selected portion (i.e., frequency band 602) of the target DFS channel (e.g., channel B) after a 60-second scan, the second device 420 can notify the control circuit 430 that the selected portion (i.e., frequency band 602) of the target DFS channel (e.g., channel B) is available. If any radar signal is detected on a selected portion (i.e., frequency band 602) of the target DFS channel (e.g., channel B) during a 60-second (or longer) scan, the second device 420 can blacklist the entire target DFS channel (e.g., channel B) for 30 minutes; that is, according to the blacklist, the target DFS channel will not be detected or used for 30 minutes. Afterward, the second device 420 can select a portion (i.e., frequency band 605) of a new target DFS channel (e.g., channel C) and scan the selected portion of the new target DFS channel for 60 seconds to determine if there is any radar signal on the selected portion (i.e., frequency band 605) of the new target DFS channel. If any radar signal is detected on the selected portion of the target DFS channel, the above operation can be repeated. It should be noted that the center frequency of the new target DFS channel may be higher or lower than the center frequency of the operating channel of the first device 410.

[0042] It should be noted that when the first device 410 is operating on channel A, it can also continuously monitor whether there is a radar signal on channel A, which can be regarded as "in-service monitoring". Specifically, assuming that the first device 410 is operating in channel A and the second device 420 detects that a selected portion of the target DFS channel (e.g., channel B) is available via a 60-second CAC scan, when the first device 410 detects a radar signal in channel A or when the first device 410 determines that channel A is busy, the first device 410 can move the wireless link 610 used for data transmission and reception from channel A to channel B.

[0043] For example, when the first device 410 detects a radar signal in the operating channel or determines that the operating channel is busy, the first device 410 will stop transmitting on the operating channel and wait for the detection result of the second device. When the second device's detection result indicates that a new channel is available after a predetermined scanning period, the first device 410 moves to the new channel. Assuming that the wireless communication device 400 is an access point and is connected to one or more client devices, before moving channels, the first device 410 of the wireless communication device 400 can send a "channel switching announcement" frame as defined in the IEEE 802.11 specification to the connected client devices to inform them which channel the wireless communication device 400 will move to. In some embodiments, when a radar signal is detected in the current operating channel of the first device 410, the second device 420 can select one of the available non-DFS channels as the target channel to move to, or select a fixed channel as the target channel to move to, but the invention is not limited thereto. It should be noted that the second device 420 can still detect a selected portion of the new target channel (i.e., it can be a DFS channel or a non-DFS channel).

[0044] After the first device 410 has successfully moved the operating channel from channel A to channel B, the first device 410 operates on channel B with the limited bandwidth previously detected by the second device 420. Then, the first device 410 performs In-Service Monitoring (ISM) for a predetermined duration (i.e., in-service monitoring CAC duration, e.g., 60 seconds) on the full bandwidth (i.e., band 603) of the operating channel (i.e., channel B) to determine if any radar signals are present in the full bandwidth (i.e., band 603) of the operating channel (i.e., channel B). Simultaneously, the control circuit 430 can control the second device 420 to select a portion (e.g., band 605) of a new target DFS channel (e.g., channel C) and periodically detect whether there are radar signals in the selected portion of the new target DFS channel.

[0045] Therefore, from the perspective of wireless communication device 400, because the second device 420 can detect the available target DFS channel in advance, the wireless link 610 used by wireless communication device 400 can quickly and seamlessly change from channel A to channel B. Furthermore, the second device 420, with its limited hardware resources, can detect available DFS channels within a limited frequency band, thereby reducing the cost of wireless communication device 400. After changing to the new available DFS channel previously detected by the second device 420, the first device 410 performs Online Service Detection (ISM). When the first device 410 detects that the entire frequency band of the new DFS channel is available (i.e., no radar signal is detected for at least 60 seconds), the first device 410 can extend the wireless link 610 from the limited bandwidth to the full bandwidth of the new DFS channel (i.e., from the limited frequency band to the full frequency band of the new DFS channel).

[0046] Therefore, users of the wireless communication device 400 will not perceive the delay caused by the change in operating channel, thus achieving "zero-wait DFS," improving user experience, and reducing the cost of the wireless communication device. Furthermore, when no radar signal is detected across the entire frequency band of the new operating channel via online service monitoring for a predetermined duration, the wireless communication device 400 further expands the bandwidth of the wireless link in the new operating channel, thereby improving the performance of the wireless communication device.

[0047] Figure 7 This is a flowchart of a zero-wait dynamic frequency selection method according to an embodiment of the present invention. Please refer to... Figures 4 to 7 .

[0048] Step S710: Establish a wireless link with the wireless communication device using the first device 410 in the first communication channel. For example, the wireless link can use the full frequency band (i.e., full bandwidth) of the first communication channel (e.g., channel A), such as... Figure 5A and Figure 6A As shown.

[0049] Step S720: Perform a first scan of the second communication channel for a first predetermined duration using the second device to detect whether there is a radar signal on the second communication channel. For example, the first scan may refer to the second communication channel (e.g., Figure 5A A CAC scan of a predetermined duration (e.g., at least 60 seconds) is performed on channel B of the second communication channel to detect the presence of radar signals on the second communication channel. Alternatively, the first scan may refer to a CAC scan on a selected portion (e.g., frequency band 602) of the second communication channel, such as... Figure 6A and Figure 6B As shown.

[0050] Step S730: In response to the first scan meeting predetermined conditions, control the first device to move the wireless link from the first communication channel to the second communication channel. For example, in Figures 5A-5B In one embodiment, a predetermined condition may instruct the first device to determine that the first communication channel is busy and that no radar signal is detected on the second communication channel during a first scan within a first predetermined duration. Additionally, the first device may perform a second scan of the first communication channel for a second predetermined duration to detect the presence of any radar signal on the first communication channel. In an alternative embodiment, the predetermined condition may instruct that a radar signal is detected on the first communication channel during a second scan within a second predetermined duration, and no radar signal is detected on the second communication channel during a first scan within the first predetermined duration. Therefore, if either of these predetermined conditions is met, the first device 410 moves the wireless link from the first communication channel to the second communication channel.

[0051] also, Figures 6A-6CThe predetermined conditions in the embodiments and Figures 5A-5B The predetermined conditions are similar in the embodiments. In response to the wireless link being moved to a selected portion of the second communication channel, the first device 410 may perform a third scan of the remaining portion of the second communication channel for a third predetermined duration, since the second device 420 previously performed a second scan of the selected portion of the second communication channel. Therefore, in response to no radar signal being detected on the remaining portion of the second communication channel by the third scan within the third predetermined duration, the control circuit 430 may control the first device 410 to extend the wireless link to the entire second communication channel. The second device may perform a fourth scan of the second selected portion of the third communication channel for a fourth predetermined duration to detect whether there is any radar signal on the second selected portion of the third communication channel.

[0052] The first, second, third, and fourth reservation durations can be the same or different.

[0053] In view of this, the present invention provides a zero-wait dynamic frequency selection (DFS) method and an apparatus using the method. The method and apparatus are based on scanning results on a first communication channel and a second communication channel. Before a first device determines to move a wireless link from an operating channel to a target DFS channel, a second device (e.g., a device with fewer hardware resources or lower computing power than the first device) can detect the availability of the target DFS channel in advance (e.g., by scanning with CAC for at least 60 seconds). This allows for a rapid and seamless change of the wireless link used by the first device from channel A to channel B, thereby achieving "zero-wait DFS" and improving the user experience.

[0054] The embodiments described herein can be implemented entirely in hardware, entirely in software, or using implementation methods that include both hardware and software elements. The embodiments can be implemented in software, including but not limited to application software, firmware, resident software, microcode, etc.

[0055] The steps described herein can be implemented using any suitable controller or processor and a software application, which can be stored in any suitable storage location or on a computer-readable medium. The software application provides instructions that enable the processor to cause the receiver to perform the functions described herein.

[0056] Furthermore, embodiments may take the form of a computer program product on an accessible computer-usable or computer-readable medium, providing program code for use by, or in conjunction with, a computer or instruction execution system. For purposes of description, a computer-usable or computer-readable medium may be any device that can contain, store, communicate, propagate, or transmit a program for use by, or in conjunction with, an instruction execution system or device.

[0057] The medium can be electronic, magnetic, optical, electromagnetic, infrared, a semiconductor system (or device), or a propagation medium. Examples of computer-readable media include semiconductor or solid-state memory, magnetic tape, a removable computer diskette, random access memory (RAM), read-only memory (ROM), hard disks, and optical discs. Current examples of optical discs include DVDs, compact disk-read-only memory (CD-ROM), and compact disk-read / write (CD-R / W).

[0058] While the invention has been described by way of example and according to preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. Rather, it is intended to cover various modifications and similar arrangements (which will be apparent to those skilled in the art). Therefore, the scope of the appended claims should be given the broadest interpretation to cover all such modifications and similar arrangements.

[0059] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A communication device, characterized by include: The first device is used to establish a wireless link with a wireless communication device in a first communication channel; The second device is used to perform a first scan of a selected portion of the second communication channel for a first predetermined duration to detect whether there is a radar signal on the selected portion of the second communication channel; as well as Control circuitry, coupled to the first device and the second device; In response to the first scan satisfying a predetermined condition, the control circuit controls the first device to move the wireless link from the first communication channel to a selected portion of the second communication channel; the predetermined condition indicates that no radar signal is detected on the selected portion of the second communication channel. In response to the wireless link being moved to a selected portion of the second communication channel, the first device performs a third scan of the remaining portion of the second communication channel for a third predetermined duration to detect whether there are any radar signals on the remaining portion of the second communication channel.

2. The apparatus of claim 1, wherein, The predetermined conditions instruct the first device to determine that the first communication channel is busy and that no radar signal was detected on a selected portion of the second communication channel during the first scan within the first predetermined duration.

3. The apparatus of claim 1, wherein, The first device performs a second scan of the first communication channel for a second predetermined duration to detect whether there are any radar signals on the first communication channel.

4. The apparatus of claim 3, wherein, The predetermined conditions indicate that a radar signal is detected on the first communication channel by the second scan within the second predetermined duration, and that no radar signal is detected on a selected portion of the second communication channel by the first scan within the first predetermined duration.

5. The apparatus of claim 1, wherein, In response to the second device detecting a radar signal on a selected portion of the second communication channel, the second device adds the second communication channel to a blacklist, according to which the second communication channel is not detected or used by the first device and the second device for a predetermined duration.

6. The apparatus of claim 1, wherein, Before moving from the first communication channel to a selected portion of the second communication channel, the first device sends a channel switching notification frame to notify the wireless communication device to move the wireless link to a selected portion of the second communication channel.

7. The apparatus of claim 1, wherein, The second device performs a fourth scan of a selected portion of the third communication channel for a fourth predetermined duration to detect whether there are any radar signals on the selected portion of the third communication channel.

8. The apparatus of claim 1, wherein, In response to the fact that no radar signal is detected on the remainder of the second communication channel during the third scan within the third predetermined duration, the first device extends the wireless link to the entire second communication channel.

9. A method of wireless communication for use in an apparatus including a first device and a second device, the method comprising: The method includes: The first device is used to establish a wireless link with a wireless communication device in a first communication channel. The second device is used to perform a first scan of a selected portion of the second communication channel for a first predetermined duration to detect whether there is a radar signal on the selected portion of the second communication channel; In response to the first scan satisfying a predetermined condition, the first device is controlled to move the wireless link from the first communication channel to a selected portion of the second communication channel; the predetermined condition indicates that no radar signal is detected on the selected portion of the second communication channel. In response to the wireless link being moved to a selected portion of the second communication channel, the first device is controlled to perform a third scan of the remaining portion of the second communication channel for a third predetermined duration to detect whether there are any radar signals on the remaining portion of the second communication channel.

10. The method of claim 9, wherein, The predetermined conditions instruct the first device to determine that the first communication channel is busy and that no radar signal was detected on a selected portion of the second communication channel during the first scan within the first predetermined duration.

11. The method of claim 9, wherein, Also includes: The first device is used to perform a second scan of the first communication channel for a second predetermined duration to detect whether there are any radar signals on the first communication channel.

12. The method of claim 11, wherein, The predetermined conditions indicate that a radar signal is detected on the first communication channel by the second scan within the second predetermined time period, and that no radar signal is detected on a selected portion of the second communication channel by the first scan within the first predetermined time period.

13. The method as described in claim 9, characterized in that, Also includes: In response to the second device detecting a radar signal on a selected portion of the second communication channel, the second device is controlled to add the second communication channel to a blacklist. According to the blacklist, the second communication channel will not be detected or used by the first device and the second device for a predetermined period of time.

14. The method as described in claim 9, characterized in that, Also includes: Before moving from the first communication channel to a selected portion of the second communication channel, the first device is controlled to send a channel switching notification frame to notify the wireless communication device to move the wireless link to a selected portion of the second communication channel.

15. The method as described in claim 9, characterized in that, Also includes: The second device is controlled to perform a fourth scan of a selected portion of the third communication channel for a fourth predetermined duration to detect whether there are any radar signals on the selected portion of the third communication channel.

16. The method as described in claim 9, characterized in that, Also includes: In response to the fact that no radar signal is detected on the remaining portion of the second communication channel during the third scan within the third predetermined duration, the first device is controlled to extend the wireless link to the entire second communication channel.

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