TW200913572A - Cognitive radio system and method - Google Patents

Abstract

A cognitive radio system and method for clear and idle channel survey in Wireless Local Area Network (WLAN) are disclosed. Through computing average value of Received-Signal-Strength-Indicator (RSSI_AVG) in each channel, clear channels without interference from other RF devices can be distinguished in the present system and method. Based on an actual WLAN setup, a further AP has a larger possibility to be an idle and clear AP. In the present system and method, searching available channels from furthest AP to nearest AP therefore helps to reduce time of channel survey through repeated rises of signal strength threshold.

Description

200913572 IX. Description of the Invention: [Technical Field] The present invention relates to a Cognitive Radio (CR) technology, in particular to determining a wireless local area network event (WLAN event) and received signal strength in a channel. The RSSI event is an independent time interval. The received signal strength indicator (RSSI) is averaged to obtain the RSSI average (RSSI-AVG) under the received signal strength indicator event, and is selected by comparing the RSSI-AVG size. Interference with clean idle channel' and the wireless local area network channel includes the national information communication infrastructure band operating in the 2.4 GHz publicly available industrial, scientific and medical band (Industry, Scientiflc and Medical band, ISM band) and without license ( Unlicensed National Information Infrastructure band, UNII band). [Prior Art] Wireless Local Area Network (WLAN) is a wireless access network architecture that enables access points (Access p〇int, Ap) and Loeal Area Netwwk (LAN) to belong to the office and home. And the wireless transmission technology applied in the public domain. The IEEE 802.il standard is adopted, in which different specifications such as a, b, and g are extended in response to different requirements. Wireless local area network (WLAN) connections should not only continue to increase in notebook computers and desktops, but also in handheld gaming consoles, game consoles, and consumer devices for digital homes (such as audio-visual equipment, printers). New accounts such as mobile phones and mobile phones continue to grow. In addition to the increasing number of applications for wireless 5 200913572 Regional Network Connections There are also many devices sharing the frequency band with wireless local area networks (WLANs) in the RF environment around the life. The IEEE 802.11 wireless local area network (WLAN) operates in the publicly available industrial, scientific, and medical (ISM band) and 5 GHz (802.11a) bands at 2_4 GHz (802.11b and 802.11g). Other wireless connectivity standards such as Bluetooth (Biuet〇〇th) and Home RF (HomeRF) also work on the ISMband, which will be used in wireless local area networks. Potential interference. In addition, randomly enabled devices such as microwave ovens (micr〇wave 〇ν6η), home wireless phones (wirelessph〇ne) or certain industrial devices also generate noise for wireless LAN connections using this public band. Numerous hotline regional network products are being used more and more, and the versatile industrial, scientific, and ISM bands and WLAN-enabled products in the _I band are not required. More and more, coupled with Bluetooth, home radio, micro- and wireless phone interference, 'the quality of the wireless local area network (WLAN) connection is greatly threatened. The traditional wireless local area network products use the transmission channel of the nearest access point (n_tAp) when selecting the available channel, and transmit the wireless local area network packet (hungry (10) whistle, only for the channel being transmitted. Ehannel) packet traffic is modulated by packet transmission, and the packet is transmitted and encapsulated by the empty slot output wire. So, come, Wei did not listen to the domain network's RF management in the fine_na, such as: in the state of the state computer disk network printers and radio frequency interference (four) no _ performance microwave oven products in the environment), 6 200913572 ', single Xiao (8) force will greatly reduce the traffic and performance of the I-line area network, even the entire wireless area network. SUMMARY OF THE INVENTION In order to solve the misjudgment caused by the determination of the presence or absence of a packet and a signal _ in the conventional wireless local area network product, the object of the present invention is to provide a cognitive radio system and method for determining a channel. The signal (channel _ _ wireless region ugly event (WLAN event) and the pure 峨 指标 指标 事件 event ( (10) () on both sides of the scale, in the touch signal strength indicator event alone Wei signal strength indicator (RSSI) for the average RSSI The average value (RSSI-AVG), because the leg-avg is equivalent to the average of the radio frequency (RF) intensity produced in the unpacked state (the hit strength indicator), it can be used as the basis for whether the channel is interfered by other RF devices. By comparing the size of RSSI-AVG, a clean available channel can be selected. To achieve the above purpose, the cognitive radio system (CRsystem) of the present invention intercepts the channel signal of the weekly RF ring, using a wireless local area network. Detector ί 124 (Wireless-Local-Area-Network-event sensor, WLAN-event sensor) and a received signal strength indicator event detector 123 (Received-Signal-S trength-Indicator-event sensor, RSSI-event sensor) identifies the time period in the signal that matches the wireless local area network event and the received signal strength indicator event, and then displays the received signal strength during the event period of the received signal strength indicator. The average value RSSI_AVG is calculated via an average computing device 13 , (average computer), and the number of packets in the wireless local area network event is also via 7 200913572

- A WLAN packet counter of the rogue domain gateway 14Q (WLAN packet counter) can be used to determine whether the channel is truly clean by recognizing the size of the road magic - AVG. Identification of interference. In addition, the present invention also uses a threshold threshold adjuster 142 (thresh〇ld adj uster) to repeatedly perform the (four) strength gatecast value of the wireless network event side, and gradually select out the range of different distance radii. The channel that the pick-up point emits. The screening is performed by a first-available channel selector 151 (lSt also selector), a second available channel filter 152 (available avaiiabie_cha_selector), and a third available channel screen 153 (yd) Avaiiabie_ch_ei selector) continues to complete 'by distance from the access point, filtering out the clean and idle available channels from far to near to save channel search time. The cognitive radio method (CR meth〇d) of the present invention intercepts the channel-segment waiting signal of the surrounding radio environment; then determines the distance of the access point (AP) transmitting the signal and detects the wireless in the signal The occurrence period of the Wireless-Local-Area-Network-event sensor (WLAN event) and the received signal strength indicator event (Received_Signal_Strength_IndicatOT_event sens% RSSI event); meanwhile, calculating the received signal strength indicator event occurrence time and The average value of the received signal strength indicator rssi_avg and the number of wireless local area network packets (MAN packets) in the wireless local area network event period; finally, the distance from the access point (Ap) from which the signal is transmitted Far and near, 8 200913572 From far to near _ out RSSI-AVG small and wlAN-CNT riding county into the available channel list (available channel list). The successful identification of interference from other RF devices has also greatly reduced the time required for channel searches. For a more complete and clear disclosure of the technical content, the object of the invention, and the effects thereof, the present invention will be described in detail below, and reference should be made to the drawings and drawings. [Embodiment] The first implementation of the cognitive radio system (CR SyStem) of the present invention, as shown in FIG. 2a, utilizes a Clean Channel Assessmem (cCA) component 121 (element) and a wireless local area network packet. The receiving component 122 (WLAN packet receiving element) constitutes an advanced clear channel assessment (ACCA) device 120, or uses a wireless area as shown in the first embodiment (please refer to FIG. 1D). The network event detector 124 and the received signal strength indicator event detector 123' are provided for the system to identify the wireless local area network event and the received signal strength indicator event. Moreover, the threshold strength adjuster 142 (threshold adjuster) is used to gradually increase the RF strength threshold of the clean channel evaluation (CCA) component to determine the threshold distance (corresponding to the RF intensity threshold). External and internal access points (AP), with the repeated increase of the Guhai RF strength threshold from small to large, the system can be used to search for available channels from far to near, with the actual application of the wireless network environment The most likely channel available 200913572 is the relationship of the farthest access point, saving time in channel search. The following is a description of the preferred embodiments of the present invention, and the description of the embodiments and the embodiments of the present invention are illustrative of the embodiments of the present invention, and are not intended to limit the invention. The structural form, the form of the component, or the order of execution of any of the technical fields of the art may be regarded as not departing from the patents of the present invention. In order to obtain a fairly correct wireless local area network event (the WLAN and the received signal strength indicator event (RSSI event) judgment, the present invention intercepts the surrounding RF environment channel - the length of the packet is long enough (waiting -) about _ milliseconds (four) The signal 110 is for analysis. As shown in FIG. 1A, the 1_mute channel signal is analyzed by the advanced clean channel evaluation (ACCA) device 120, and the channel signal 11 is analyzed to be in compliance with the wireless local area network event ( WLAN event) and the received signal strength indicator event for two periods. When the ambition is to evaluate the meta-input strength or the WLAN packet and the preamble signal strength strength) A broadcast value greater than or equal to a radio frequency strength (Rp touches her-Η) %' outputs a non-dear channel result; otherwise, a clean channel (dear) channel result is output. Figures 2A and 2B show how the Advanced Clean Channel Assessment (ACCA) device determines the wireless local area network event occurrence period and reception based on the clean channel assessment (CCA) component 121 and the wireless local area network packet receiving the packet 122 result. Signal strength indicator event occurrence period. 10 200913572 Among them, in order to prevent the clean channel evaluation (CCA) component from glitch misjudgment results due to other electronic components, wait for T1 time to obtain a stable clean channel assessment (CCA) result; in addition, to avoid detection To receive the signal strength indicator event (RSSI event) too many times, the result of the wireless local area network event (WLAN eveni) is the intersection, after the reception of the signal strength indicator event (RSSI event), wait for the T2 time to re-test Receiving the §fl strength index event (RSSI event), the wireless local area network event (WLANevent) as shown in FIG. 2A has the opportunity to be detected in the T2 time; similarly, when no packet has been received, After the T3 time is not maintained, the new WLAN event can be detected. At the same time, after receiving the packet, the WLAN receiving component continues to increase beyond the τ4 day punctuality. 'The output will be the result of the packet. From the example shown in Figure 2 and Figure 2, the RS SI event occurs in the clean channel assessment ((: (5) results are not clean channels (10) and the wireless area network packet The result of the receiving component is that no packet is detected; and the wireless local area network event occurs when the clean channel evaluation (CCA) result is a non-clean channel (four) rainbow channel, and the wireless local area network packet receiving component result is When the debt is detected in the packet. After the knives identify the wireless local area network event (the WLAN and the received signal strength indicator event (RSSIevent), the number of blocked packets in the absence of the secret network event (music track 6 coffee) is caused by - The wireless local area network packet counting component (de-AN packet calculates ιαν^ντ; and the received signal strength indicator event (leg 200913572 event) occurs within the received signal strength indicator average value is calculated by an average computing component 130 (average computer) RSSI Average value (RSSI_AVG). As shown in FIG. 1A, the first available channel filter 151 (lst available-channel selector) first filters the channel with the RSSI_AVG less than or equal to a MIN-RSSI-VAL value. 'Filter the channels that match the WLAN-CNT to zero channel to the available channel list 16〇(availaWe channel list), so you can select the channel that is not interfered by other RF devices. At the same time, if all the access points are Shooting (four) degrees - the size of the RSSI value can be used as the location of the access point near the far field. The RF threshold threshold THR used by the advanced clean acca device is pure or equal to The RF strength threshold THR-A channel has its WLAN-CNT zero and its access point position should be outside a distance radius AMius A). So the channel selected by ΑΝ-ΝΤ ΝΤ is also the distance radius. The wireless local area network access point 310 is not detected outside of A (radius Α). After completing the search of all channels, the threshold value adjuster 142 (threShold peak (4) is used to measure the advanced clean channel evaluation (ACCA) The RF intensity of the implanted value is increased to THR-B', and the muscle tear event is measured again. At the same time, the pro-RSSI-AVG (four) of the _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ In the 'then as shown in the mth picture, the second Use the channel screening source l52 (2nd available_ch surface i sdect〇r) to sequentially identify the channel from small to large RSSI-AVG in the sorted list. If the channel does not detect the wireless local area network event, then the frequency is turned over. The person should be able to exclude the channel from the sorted list 12 200913572 'Because the RF strength threshold has been raised to THR-B, while the tear is detected outside the half-inch A to detect the wireless local area network The access point has been excluded, so the read-free side-line area _way event is the no-line area network access point 320 located between the distance A and the distance #B. After completing the second available primary selection, all the sorted list towel channels _, the content of the door frame is adjusted to $42 (threSh〇ld adjuster), the RF intensity is pinched to THR-C' and then executed again. The second track filter can filter out the wireless area network access point located between the distance B and the distance radius c. The replaying action and execution of the re-sampling _ two can be used to screen the ϋ and · three available frequency selectors to achieve the purpose of screening wireless local area network access points from far to near. The wireless local area network access point within the distance radius c shown in Figure 1C of the stern can be borrowed. Haidi - the available channel peak selector 153 (3rd ava threat e_ch coffee - 〇r) compares the frequency of the frequency 340, 34 342 WLAN_CNT value, and filters the more idle channels into the list of available channels. Tree_from far to near_riding the available channel, which is similar to the situation in most cases when the wireless local area network uses the neighboring wireless area ugly devices (eg, network printers, wireless headsets, wireless phones, etc.); Compared to the wireless local area network access point 34 adjacent to the user, the access point 3ι farthest from the user has the best chance of being idle. When the radio frequency strength transmitted by each wireless local area network access point is the same, it is placed at the remote point of the access point 31Q, which is placed by the side shot (four) degree to the nearest access point 3 20 of the measured radio frequency The intensity comes weak. Therefore, the present invention utilizes repeatedly raising the 13 200913572 RF strength threshold and executing the first and first available channel filters, and screening the available channels from far to near, enabling more and more to find available channels to save channel search. The time provides good wireless transmission speed. If the RF strength of the gate is set to the RF strength of the dish - a when the distance from the radius A _us A), the wireless area is connected to the clean and flat evaluation of the training, and the result is clean. Forcing (5) (4)' and within the distance radius A (appearing a), the clean channel evaluation result of the line area access point 32q is non-clean. For example, if you select WLAN-CNT in the first available channel filter, you can select the channel outside the selection channel a as the available frequency, and then increase the RF strength threshold (such as: THR_A<Tm-BcTHRj:) 'Stepwise to filter the channels 汹, 330, 340, 341, 342 in the radius radii b, c and finally the distance radius C, then you can select 1$ long distance first. The channel saves channel search time. The sensible wireless f method of the present invention is a wireless-local-Area-Network-event sensor (WLAN event) and a received signal strength indicator event (Received-Signal-Strength-Indicator- Event sensor, RSSI event) Β^Γ. δ海 wireless local area network event means that a wireless local area network packet (WLAN packet) is detected in the signal and the packet prologue (reambie) signal strength is greater than or specific to a radio frequency strength threshold value. When the blood is received, the received signal strength indicator event means that no wireless zone 14 200913572 domain network packet (WLAN Packet) is detected in the signal and the signal strength is greater than or equal to the RF strength gate. At the time of the RF strength threshold, the RSSI-AVG is obtained by averaging the received signal strength indicators for the receiving-hole number strength indicator event period, and the number of packets WLAN-CNT in the wireless local area network event period is calculated. Use the channel with the RSSI_AVG and the muscle money (3) to zero to select the free channel that is not interfered by other RF devices into the available channel list, and after all channel screening is completed, it will not be included in the available channel. The list channel is stored in the sorting list according to its RSSI-AVG value from small to large to save the recalculation of RSSI-AVG. Increase the RF strength threshold (THR A _> TmjB) again to make the RF strength less than the RF strength threshold (RSSI < THR printed frequency, this is not detected wireless area Network events, and include the list of available channels in the order of the sorted list, and exclude the channels that have been included in the list of available channels from the sorted list. Different from the first use of THR-A RF strength threshold to select the distance radius For wireless local area network access points other than A, use THR-B as the RF strength threshold 彳It value to select the wireless area network access point outside the radius B. Since the channel in the sorted list is the distance radiusΑ The channel inside is equivalent to selecting the wireless area network access point between the distance B and the distance radius A. Repeatedly raise the RF strength threshold (THR-B -> THR -C), the wireless area network access point screening between the distance radius C and the distance radius B can be performed again. With such a near-far order screening, the channel most likely to be idle will be preferentially screened by 15 200913572 The selected channel list can be selected. Finally, the channel within the radius c can also select the more free channel as the available channel by comparing its WLAN-CNT size. In addition, the RSSI-AVG value can be completed. After sorting the list, delete the channel with too large RSSI-AVG in the sorted list. For example, the channel of the oversized RSSI-AVG is the largest RSSI-AVG of all ships, and the largest RSSDAGG RSSLAVG ^^l (difference) of all lying A^-^I^^ msABLE—RSSI_VAL. Tick _ more channels than other county-related interference. In order to avoid the fact that the channel RSSI event | 士士敏二θ 旰 凋 凋 凋 凋 太 太 太 太 太 太 太 太 WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN WLAN Whether it is more than 300 microseconds apart, only iirou k ^ ensures that the WLAN event between the face RSSI events has enough time to be measured. The above-mentioned 'the invention can be connected to the heart' to achieve the intended purpose, to provide a solution to the problem of the distribution of the Wei domain network, the choice of the mine, the presence or absence of the package and the signal == created: the misjudgment • no green power system And method. It is extremely useful for the use of the industry, and the friend has filed a patent claim. To. It will be apparent to those skilled in the art that the present invention may be practiced without departing from the scope of the invention. 16 200913572 [Simplified description of the drawings] 1A-1C_ is a schematic diagram of the first embodiment of the cognitive radio of the present invention. The first 1D diagram of the Cognitive Radio (CR) system of the Cognitive Radio (CR) system is a schematic diagram of the two embodiments of the cognitive radio of the gamma.

Fig. 2B of the Cognitive Radio (CR) system illustrates how the cognitive radio (four), CR) system of the present invention can receive the event strength indicator event. Fig. 3A is a diagram showing the wireless local area network access points distributed in four areas separated by three distance and half control in the embodiment of the present invention. Figure 3B is a diagram (4) In the embodiment of the present invention, the wireless local area network access point is located in the innermost distance from the semi-controlled area. [Major component symbol description] 110: 1000ms channel signal 120: Advanced clean channel evaluator 121. Clear Channel Assessment (CCA) component 122: Wireless LAN packet receiving component (music heart (10) old 123 123) Receive δ 凡 intensity indicator event detector (Rssj_event sens〇r) 124. Broadcast line area network event detector (wjHeventsensor) 17 200913572 13 〇 average 5 different elements 130 (average computer) 140 . Wireless Regional network packet counting component (WLANpacketc〇unter) 142. Gate I value adjuster (such as esh〇idadjuster) 150: Sorting list (sorting (4) 151 1 channel available channel filter (1 st available-channel selector) 152 brother - available channel 2nd available-channel selector 153 3rd available-channel selector 'Available channel list T1. Waiting time' after the CCA result is valid (to prevent surge interference) T2. Waiting time, after the next RSSI event can be detected Τ3. Waiting time, after the packet is still unpacked, the wireless LAN event is released. The next wireless zone event Τ4: Stabilization time, there is an increase of 310' from the wireless area network access point 320 outside the radius a. Wireless area network access between the radius B and the distance radius a Point 330 is a wireless area network access point 340 between the half control and the distance half b: a wireless area network access point 341 within a distance radius c. The wireless area network access point 342 within the radius c : Wireless LAN access point 18 within radius c

Claims (1)

200913572 X. Patent application scope: 1 · A Cognitive Radio (CR) system for identifying Wireless Local Area Network (WLAN) channels that are not interfered by other Radio Frequency (RF) devices (channel), including: (a) a Wireless-Local-Area-Network-event sensor (WLAN-event sensor) for the wireless area in the signal input (signai) (b) A Received-Signal-Strength-Indicator-event sensor (RSI-event sensor) is used to detect the received signal strength indicator event in the input channel signal. (c) an average calculation component (average c〇mputer) for calculating the received signal strength indicator average RSSI_AVG of the channel when the received signal strength indicator event occurs; (8) a wireless local area network packet Counting component ^ ^ milk ship mouth address price (four) 'provided the number of wireless local area network packets of the channel when the wireless local area network event occurs WLAN_CNT; (8) one The first available channel filter... is uniquely touched by the ambience (6) gamma to filter out the RSSI-AVG small and WLAN-CNT zero channel into an available channel list' and after all channels have been filtered , will be 19 200913572 not, the channel into the list of available channels can be stored in the sorting list according to its RSSI-AVG value from small to large; (0 brother with channel filter (2nd available- Channel selector) for including channels that have not detected a wireless local area network event into the list of available channels in the order of the sorted list' and excluding the channels that have been included in the list of available channels from the sorted list; and (g) The younger brother-"T's channel selector (3rd avaiiabie_channel selector), according to the ranking, the frequency of WLAN-CNT is large, and the channel from small to large is included in the list of available channels, where The wireless local area network channel includes the Industriai, scientjflc and medical band (ISM band) and the unlicensed national information channel. The basic construction of the band (Unlicensed National Information Infrastructure band, UNII band) on. 2. The cognitive radio system of claim 2, wherein the wireless local area network event detects a wireless local area network packet (WLAN packet) and the packet preamble signal strength (signal strength) ) is greater than or equal to an RF strength threshold. 3. The cognitive radio system of claim 1, wherein the received signal strength indicator event is that no wireless local area network packet (Wlan packet) is detected and the signal strength is greater than or equal to RF strength threshold 〇20 200913572 4. The cognitive radio system of claim 2, further comprising: a threshold adjuster for the first available channel After the sorting list is completed by the 1st available-channel selector, the RF strength threshold (THR-A->THR B) is raised, and the wireless area network detection is restarted. The channel that causes the RF strength to be less than the RF strength threshold (RSSI < THRJ3) does not detect a wireless local area network event for the second available channel filter (2nd avaiiable-Channd selector) to filter the available channels, wherein the gate The broadcast adjuster can be repeatedly activated to gradually increase the threshold of the RF strength threshold to complete the screening function of the channels in different distance radius ranges. 5. The cognitive radio system of claim 1, further comprising: a Clear Channel Assessment (CCA) element; and a WLAN packet receiving dement , constitutes the Advanced Clean Channel Assessment (ACCA) device for detecting the occurrence of wireless local area network events and received signal strength indicator events in the input channel signal. Q 6. The perception as described in claim 5 The radio system, wherein the wireless local area network event refers to the Clean Channel Assessment (CCA) result being non-clear and receiving a wireless network packet receive. 7. The cognitive radio system of claim 5, wherein the receiving 21 200913572 nickname strength indicator event means that the Qa Channel Assessment (CCA) result is non-clear and No packet received by the wireless network packet (no packet received). 8. The cognitive radio system of claim 5, wherein the clean channel evaluation component outputs a non-ciar channel when the input signal strength is greater than or equal to a RP strength threshold. The result; otherwise 'outputs a clear channel result. 9. The cognitive radio system of claim 5, wherein the clean channel evaluation component is detecting a WLAN packet and the preamble signal strength is When the RF strength threshold is greater than or equal to one, the non-clear channel result is output; otherwise, the clean channel (dear) channel result is output. The cognitive radio system of claim 1, wherein the first available channel selector (1st available-channel selector) filters out an RSSI average (R_SSI_AVG) that is less than or equal to a minimum average value (1st available-channel selector). MIN_RS SI_AVG) The channel with the number of wireless local area network packets (WLAN_CNT) is zero is included in the list of available channels. A cognitive radio (CR) method for identifying a wireless local area network (WLAN) channel that is not interfered by other radio frequency (RF) devices, including the following steps: 22 200913572 (8) Intercepting the input channel for a waiting time (Yingfu); (b) Detecting the occurrence period of the Wireless-Local-Area-Network-event sensor (WLAN event) (c) detecting the occurrence period of the received signal strength indicator event (Received-Signal-Strength-Indicator-event sensor, RSSI event); [6) calculating the received signal strength indicator in the event period of the received signal strength indicator event The average value RSSI_AVG; (8) calculating the number of wireless local area network packets WLAN_CNT in the wireless local area network event occurrence period; and (f) screening the channel with the RSSI_AVG small and WLAN-CNT zero to be included in the available channel list (available channel list) ), and after all channel screening is completed, the channel that is not included in the list of available channels depends on its RSSI-AVG value. The small to large row V is stored in the sorting list, where 'the wireless local area network channel includes the industrial, scientific and medical band (Industrial, Scientific and Medical band, ISM band) operating at 24 GHz. ) and the NationaHnformation Infrastructure band (UNII band) of the national information communication infrastructure band (10) that does not require a license. 12. The cognitive radio method of claim 5, wherein the waiting time is a sufficient time (1 〇〇〇 millisecond) to analyze the correct 23 200913572 RSSI AVG and WLAN CNT. 13. The method of claim 44, wherein the wireless local area network event refers to a WLAN packet in the signal and the preamble signal strength of the packet. (signa) [strength] is greater than or equal to a radio frequency strength threshold (Rp erythrocyte sedimentation rate is as detailed as (6). 14. The cognitive radio method of claim n, wherein the receiving scream strength indicator event system It means that when the WLAN packet is not detected in the signal and the signal strength is greater than or equal to a radio frequency strength threshold (Rpstrengththresh〇丨d), I5·If the patent scope is 帛The cognitive radio method of claim 13 further comprising the step of: increasing the RF strength threshold (THR-A->THR-B) after completing the sorted list of RSSI-AVG values. So that the RF strength is less than the channel of the RF strength threshold from the SSI<THR-B), the wireless local area network event is not detected, and the list of available channels is included in the order of the sorted list. It has been included in the list of available channels excluded from the channel list order. 16. The method of perceptual radio described in Item 15 of the patent application, further includes the following steps: raising the RF strength threshold (Tm-C) to make the intensity less than riding (four) Broadcast value I rrR-c) thief domain scale area network transfer, and in accordance with the sorting > month early order can be a list of people, while the already available channel list 24 200913572 channel from the Sort list exclusion. The cognitive radio method described in item 5, further comprising the steps of: according to the size of the hunt value of each channel in the sorted list to the list of available channels. 18. The method as claimed in claim 5, further comprising the steps of: after completing the sorted list of RSSI_AVG values, deleting the sorting, the channel in the main list that is obviously interfered by other devices, Save time on channel search. 19. The method of claim 3, wherein the channel in the sorted list that is significantly interfered by other radio frequency devices means that the RSSI-AVG of the channel is the largest among all channels, and in all channels The difference between the maximum RSSI-AVG and the minimum RSSI-AVG (the hitting kiss is greater than the cull value disable_rssijval. 20. The method of perceptual radio as described in claim 5, further comprising the steps of: before incorporating the list of available channels It is still necessary to detect whether it is zero or not. The side channel RSSI event is too frequent to measure the wlaN event so that the WLAN_CNT is equal to zero. 21. The cognitive radio method according to claim 2, wherein The illusion of detecting WLAN-CNT zero is to detect whether there is more than 300 microseconds between two RSSI events to ensure that the wlan event between the two RSSI events has enough time to be measured.