WO2022213703A1 - 网络拓扑的识别方法、装置及无线通信系统 - Google Patents

网络拓扑的识别方法、装置及无线通信系统 Download PDF

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Publication number
WO2022213703A1
WO2022213703A1 PCT/CN2022/072751 CN2022072751W WO2022213703A1 WO 2022213703 A1 WO2022213703 A1 WO 2022213703A1 CN 2022072751 W CN2022072751 W CN 2022072751W WO 2022213703 A1 WO2022213703 A1 WO 2022213703A1
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path loss
terminal
target terminal
signal strength
received signal
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PCT/CN2022/072751
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English (en)
French (fr)
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魏启坤
贺渊
和海洋
占俊
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华为技术有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/02—Arrangements for optimising operational condition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/12—Wireless traffic scheduling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/12—WLAN [Wireless Local Area Networks]

Definitions

  • the present application relates to the field of communications, and in particular, to a method, a device, and a wireless communication system for identifying a network topology.
  • a thin access point (fit access point, FIT AP) is a centralized wireless local area network (wireless local area networks, WLAN) architecture.
  • APs and at least one station (station, STA).
  • the AP can provide wireless access services for the STA, and the AC can manage and control multiple APs in a unified manner.
  • the AC can also determine the network topology between APs based on the path loss between APs (path loss for short), and then manage and control each AP based on the network topology.
  • the present application provides a network topology identification method, device and wireless communication system, which can solve the technical problem of low reliability of the network topology determined based on the path loss between APs.
  • the technical solutions are as follows:
  • a method for identifying a network topology comprising: a controller determining a network topology between a first AP, a second AP and a target terminal, wherein the target terminal is associated with the first AP, and the second AP is associated with the target terminal.
  • the AP is a neighbor AP of the first AP
  • the network topology includes: a first path loss, a second path loss, and a third path loss; the first path loss is the path loss between the first AP and the target terminal, and the second path loss is the path loss between the first AP and the target terminal.
  • the path loss is the path loss between the second AP and the target terminal, and the third path loss is the path loss between the first AP and the second AP.
  • the network topology determined by the controller includes not only the path loss between two APs, but also the path loss between the AP and the terminal. Since the path loss between the AP and the terminal can accurately reflect the signal transmission performance of the link between the AP and the terminal, and can accurately reflect the degree of interference between downlink signals sent by different APs, the reliability of this network topology is high. . Furthermore, it can ensure high reliability when the AP is managed and controlled (for example, radio frequency tuning) based on the network topology.
  • the method may further include: determining the AP with the smallest path loss between the first AP and multiple neighboring APs of the first AP and the target terminal as the home AP to which the target terminal belongs; The terminal of the home AP determines the ideal coverage of the home AP.
  • the ideal coverage of the home AP can be used for radio frequency tuning, so that all terminals located within the ideal coverage can associate with the home AP. That is, the radio frequency optimization based on the ideal coverage can enable the terminals to associate with the AP with the smallest path loss. In this way, it can be ensured that the AP does not need high transmit power to make the received signal strength of the terminal meet the requirements of communication quality, and further, interference caused by excessive AP power can be avoided on the premise of ensuring the signal coverage quality of the AP.
  • the method may further include: for any AP in the first AP and the second AP, determining whether the any AP is a high-hanging AP based on the path loss between the any AP and the multiple terminals,
  • a high-hanging AP refers to an AP whose distance to multiple terminals is greater than the distance threshold, or that there are obstructions between multiple terminals.
  • the controller identifies an AP as a high-hanging AP, it can determine that the path loss between the AP and the terminal is relatively large.
  • the transmit power of the high-mounted AP can be adjusted to be higher, so as to ensure that the received signal strength of the terminal can meet the requirements of communication quality.
  • the multiple terminals may be terminals located within the ideal coverage of any AP; based on the path loss between any AP and multiple terminals, the process of determining whether any AP is a high-hanging AP may include: If the path loss between the any AP and the terminal located within the ideal coverage of the any AP is greater than the first loss threshold, then the any AP is determined to be a high-hanging AP.
  • the controller may determine that the distance between the deployment position of the AP and the distribution plane of the terminal is far away, or there is an obstruction between the AP and the distribution plane of the terminal object, and then it can be determined that any AP is a high-hanging AP.
  • the method may further include: if the path loss between the first AP and the terminal located in the ideal coverage area of the first AP is less than the second loss threshold, the second AP and the terminal located in the ideal coverage area of the first AP The path loss between the terminals in the device is less than the second loss threshold, and the third path loss between the first AP and the second AP is greater than the third loss threshold, then it is determined that there is a gap between the first AP and the second AP cover.
  • the blocking situation between APs determined by the controller can also be used as a basis for subsequent radio frequency tuning of APs, so as to improve the reliability of radio frequency tuning.
  • the method may further include: performing radio frequency tuning on at least one of the first AP and the second AP based on the network topology between the first AP, the second AP and the target terminal.
  • the network topology determined by the controller can also reflect the signal transmission performance between the AP and the terminal, radio frequency tuning based on the network topology has a better effect.
  • the method may further include: for any one of the first AP and the second AP, adjusting the The transmit power of any AP, so that the strength of the signal sent by any AP detected by the terminals located in the ideal coverage of the AP is greater than the strength threshold.
  • the method may further include: allocating a channel of the first frequency to the first AP, and allocating a channel of the second frequency to the second AP; wherein, if the first AP is located within the ideal coverage of the second AP, The path loss between the terminals is greater than the fourth loss threshold, and the path loss between the second AP and the terminal located in the ideal coverage of the first AP is greater than the fourth loss threshold, then the frequencies of the first frequency and the second frequency are The difference is less than the first frequency threshold, that is, the frequencies of the channels allocated to the two APs may be equal or similar; if the path loss between the first AP and the terminal located in the ideal coverage of the second AP is less than the fifth loss threshold, or , the path loss between the second AP and the terminal located in the ideal coverage of the first AP is less than the fifth loss threshold, then the frequency difference between the first frequency and the second frequency is greater than the second frequency threshold, that is, two APs
  • the frequencies of the allocated channels are quite different; wherein, the fourth loss
  • the controller can allocate a channel with the same or similar frequency to the two APs when it is determined that the interference between the downlink signals of the two APs is relatively small, and can assign a channel for the two APs when the interference between the downlink signals of the two APs is relatively large.
  • Each AP allocates channels of different frequencies to avoid co-channel interference. Since the number of channels that can be allocated in the system is limited, based on the above channel allocation method, it can be ensured that the co-channel interference of the entire system is small.
  • the method may further include: receiving a first received signal strength and a second received signal strength sent by a first AP, where both the first received signal strength and the second received signal strength are sent by the target terminal to the first AP wherein, the first received signal strength is the strength of the first measurement frame sent by the first AP detected by the target terminal, and the first measurement frame carries the basic service set identifier (basic service set identifier, BSSID) of the first AP, The first received signal strength is used to determine the first path loss; the second received signal strength is the strength of the second measurement frame sent by the second AP detected by the target terminal, and the second measurement frame carries the BSSID of the first AP. The second received signal strength is used to determine the second path loss.
  • BSSID basic service set identifier
  • the second AP can disguise as the first AP and send the measurement frame to the target terminal associated with the first AP, thereby ensuring that the first AP can obtain the downlink between the second AP and the target terminal The received signal strength of the channel.
  • the method may further include: before receiving the first received signal strength and the second received signal strength sent by the first AP, sending a detection instruction to the first AP, where the detection instruction is used to instruct the first AP to trigger the target
  • the terminal detects the received signal strength; based on the detection result sent by the first AP within the first period, the detection success rate of the target terminal is determined, wherein the detection result is used to indicate whether the first AP has received feedback from the target terminal If the detection success rate is greater than or equal to the success rate threshold, it is determined that the target terminal has the ability to detect the received signal strength in the second period after the current moment; based on the target terminal having the ability to detect the received signal strength, Send a strength measurement instruction for the target terminal to the first AP, where the strength measurement instruction is used to instruct the first AP to obtain the first received signal strength and the second received signal strength; wherein, the detection success rate is received within the first period of time The ratio of the number of received target detection results to the total number of detection results received within the first period, where the target
  • the controller can start the measurement of the target terminal after determining that the target terminal has the ability to detect the received signal strength, thereby avoiding waste of network resources caused by invalid measurement.
  • the method may further include: using a boxplot algorithm to process the detection success rates of the multiple terminals determined within the third time period to obtain the success rate threshold.
  • the boxplot algorithm can truly and intuitively represent the distribution of observed values, it can be ensured that the success rate threshold determined based on the boxplot algorithm has high reliability.
  • the first AP has multiple neighbor APs including the second AP, and after the multiple neighbor APs are sorted in ascending order of path loss with the first AP, the arrangement of the second APs
  • the sequence number may be less than or equal to N, where N is a positive integer less than or equal to the total number of the multiple neighbor APs.
  • the controller may only consider the neighbor with the smaller path loss to the first AP AP. Therefore, on the premise of ensuring the reliability of the identified network topology, the calculation amount of the network topology identification process can be effectively reduced, and the identification efficiency of the network topology can be improved.
  • a controller in another aspect, has the function of implementing the method for identifying the network topology provided by the above aspects, the controller includes at least one module, and the at least one module can be used to implement the network provided by the above aspects. How to identify the topology.
  • a controller comprising: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implements the above-mentioned aspects when the processor executes the computer program Provides a method of identifying the network topology.
  • a computer-readable storage medium stores instructions, the instructions are executed by a processor to implement the method for identifying a network topology provided by the above aspects.
  • a computer program product containing instructions, which, when the computer program product is run on a computer, causes the computer to execute the method for identifying a network topology provided by the above aspects.
  • a wireless communication system comprising: a plurality of APs, and a controller as provided in any of the foregoing aspects connected with the plurality of APs.
  • the present application provides a method, device and wireless communication system for identifying a network topology.
  • the network topology between the first AP, the second AP and the target terminal determined by the controller includes not only the path loss between the two APs, but also the path loss between the AP and the terminal. Since the path loss between the AP and the terminal can not only accurately reflect the signal transmission performance of the link between the AP and the terminal, but also accurately reflect the interference degree between the downlink signals sent by different APs, the reliability of this network topology is relatively high. high. Furthermore, it can be ensured that the management and control of the AP based on the network topology (for example, radio frequency tuning) has a better effect.
  • FIG. 1 is a schematic structural diagram of a wireless communication system provided by an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of another wireless communication system provided by an embodiment of the present application.
  • Figure 3 is a schematic diagram of channel division in the 5GHz frequency band
  • FIG. 4 is a schematic structural diagram of another wireless communication system provided by an embodiment of the present application.
  • FIG. 5 is a schematic diagram of a deployment scenario of an AP provided by an embodiment of the present application.
  • FIG. 6 is a schematic diagram of another AP deployment scenario provided by an embodiment of the present application.
  • FIG. 7 is a schematic diagram of a network topology provided by an embodiment of the present application.
  • FIG. 8 is a flowchart of a method for identifying a network topology provided by an embodiment of the present application.
  • FIG. 9 is a schematic diagram of obtaining a first received signal strength by a first AP according to an embodiment of the present application.
  • FIG. 10 is a schematic diagram of obtaining a second received signal strength by a first AP according to an embodiment of the present application
  • FIG. 11 is a schematic diagram of a first measurement information provided by an embodiment of the present application.
  • FIG. 12 is a schematic diagram of a second measurement information provided by an embodiment of the present application.
  • FIG. 13 is a schematic diagram of an actual coverage range and an ideal coverage range of an AP provided by an embodiment of the present application.
  • FIG. 14 is a flowchart of a method for generating a terminal portrait by a controller according to an embodiment of the present application
  • 15 is a schematic structural diagram of a controller provided by an embodiment of the present application.
  • 16 is a schematic structural diagram of another controller provided by an embodiment of the present application.
  • 17 is a schematic structural diagram of another controller provided by an embodiment of the present application.
  • FIG. 18 is a schematic structural diagram of still another controller provided by an embodiment of the present application.
  • the system may be a WLAN with a FIT AP architecture using a locally deployed controller, or a WLAN with a cloud hosting controller management architecture.
  • the system may include: a controller 01, and a plurality of APs 02, all of which may be connected with the controller 01.
  • the system may also include at least one terminal 03, and the terminal 03 may be associated with an AP 02 to obtain wireless access services provided by the AP 02 associated with it.
  • the terminal 03 can first send an association request to the AP 02 that can be detected, and if a certain AP 02 responds to the association request, the terminal 03 can establish an association with the AP 02.
  • the controller 01 may be a wireless controller, for example, an AC.
  • the controller 01 can also be a server independent of the AC and capable of communicating with the AP 02.
  • AP 02 can be a network device such as a router or switch that supports WLAN.
  • the terminal 03 may also be referred to as a STA, which may be a WLAN-enabled device such as a mobile phone, a computer, a wearable device, or a smart home device.
  • the wireless access service provided by a single AP 02 can be called a basic service set (basic service set, BSS), and the BSS can be identified by a BSSID, which can be the medium access control of the AP 02 (media access control, MAC) address.
  • BSS basic service set
  • MAC media access control
  • the wireless access service provided by multiple APs 02 connected to the same AC may be called an extended service set (ESS), and the ESS may be identified by the same service set identifier (SSID) .
  • ESS extended service set
  • SSID service set identifier
  • FIG. 2 is a schematic structural diagram of another wireless communication system provided by an embodiment of the present application.
  • the system may also include: a convergence layer located at the convergence layer Switch 04, core switch 05 at the core layer, firewall 06 and router 07.
  • the AP 02 is located at the access layer, and it can access the Internet or a wide area network (wide area network, WAN) through the cascaded aggregation switches 04, core switches 05, firewalls 06 and routers 07.
  • the system may further include an access switch 08 at the access layer, and the access switch 08 may be connected to the aggregation switch 04 and the terminal 03 respectively, for connecting the terminal 03 to the network.
  • the controller 01 can be located at the convergence layer, and is connected to a plurality of APs 02 through a core switch 05. Certainly, the controller 01 may also be located at the core layer or other locations, which are not limited in this embodiment of the present application.
  • the AC can manage and control multiple APs 02 connected to it based on the network topology between the APs 02.
  • the AC may perform radio frequency tuning on the plurality of APs 02, wherein the radio frequency tuning includes adjusting at least one parameter in the transmit power of the APs 02 and the channel.
  • adjusting the transmit power of the AP 02 can realize the adjustment of the strength of the signal sent by the AP 02. Moreover, the higher the transmit power of AP 02, the stronger the signal strength of AP 02, the larger the coverage area of AP 02, and the greater the interference to neighboring APs. Therefore, the principle that the AC adjusts the transmit power of the AP 02 may include: the closer the distance between the AP 02 and the neighbor AP is, the smaller the transmit power of the AP 02 is adjusted.
  • the neighbor AP of AP 02 may refer to an AP whose signal can be detected by AP 02, or an AP whose detected signal strength is greater than a certain threshold.
  • Adjusting the channel of the AP 02 may include at least one of adjusting the frequency of the channel and adjusting the bandwidth of the channel.
  • FIG. 3 is a schematic diagram of channel division in a 5 gigahertz (GHz) frequency band.
  • the frequency range of the 5GHz frequency band is 5.15GHz to 5.825GHz
  • the 5GHz frequency band can be divided into 24 non-overlapping channels with a bandwidth of 20MHz.
  • the frequency band from 5.15GHz to 5.35GHz includes 8 channels with a bandwidth of 20MHz, and the channel numbers of the 8 channels are 36, 40, 44, 48, 52, 56, 60, and 64 in sequence.
  • the WLAN also supports bonding several adjacent channels into a channel with a wider bandwidth to provide a higher signal transmission rate. For example, two adjacent channels can be bound to a channel with a bandwidth of 40 MHz.
  • the principle of AC adjusting the channel of AP 02 may include: avoid allocating a channel of the same frequency to adjacent AP 02, that is, the closer the distance between the two AP 02, the smaller the probability of allocating a channel of the same frequency; The farther the distance between the two, the greater the probability of allocating the same frequency channel.
  • the same-frequency channel may refer to a channel with the same frequency and bandwidth.
  • the frequency of the channel may refer to the center frequency of the channel.
  • the AC generally determines the network topology of the system based on the path loss between adjacent APs 02.
  • the path loss refers to the loss caused by the propagation of the signal in the path, and the path loss may be equal to the difference between the transmit power of the signal transmitter and the strength of the signal received by the signal receiver.
  • WLAN is a three-dimensional space composed of APs and terminals, and the path loss between APs can only reflect the two-dimensional topology of the AP deployment plane.
  • consideration For example, in Fig. 4, it is assumed that terminals STA1 and STA2 are associated with AP1, and AP2 and AP3 are AP1's neighbor APs, then the downlink signals of AP2 and AP3 will cause interference to the downlink signals sent by AP1 to STA1 and STA2, thereby affecting STA1 and STA2 business experience. That is, the signal transmission between the AP deployment plane and the terminal distribution plane is also an important factor affecting the terminal service experience.
  • the two-dimensional topology determined based on the path loss between APs cannot take into account the signal transmission between the AP and the terminal, resulting in low reliability of the two-dimensional topology.
  • radio frequency adjustment is performed based on the two-dimensional topology of the AP deployment plane. It will lead to unsatisfactory tuning results in some complex deployment environments.
  • APs 02 for example, AP1 and AP2 in FIG. 5
  • the distance between adjacent APs 02 is relatively short.
  • the ceiling or suspended ceiling
  • the transmit power of the multiple APs 02 will be adjusted to be lower.
  • the distance between the AP 02 and the terminal (for example, STA1 in FIG. 5 ) is relatively long, or because there are obstacles such as a ceiling or a suspended ceiling between the AP 02 and the terminal, the strength of the signal sent by the AP detected by the terminal is weaker.
  • the negotiation rate between AP 02 and the terminal will decrease, that is, the data transmission rate between AP 02 and the terminal will decrease, and in severe cases, the terminal may be dropped.
  • the scenarios shown in (a) and (b) of FIG. 5 are examples of deployment scenarios of high-mounted APs.
  • APs that are far away from the terminal due to their high installation position, or APs that have obstacles such as ceilings or suspended ceilings between them and the terminal may be collectively referred to as high-mounted APs.
  • the embodiment of the present application provides a method for identifying a network topology, which can solve the technical problem that the reliability of the network topology determined based on the path loss between APs 02 is low.
  • the method provided in this embodiment of the present application can be applied to a controller, for example, can be applied to the controller 01 in the system shown in FIG. 1 or FIG. 2 .
  • the controller can determine the network topology between the first AP, the second AP, and the target terminal, where the target terminal is associated with the first AP, and the second AP is of the first AP. neighbor AP.
  • the network topology includes: a first path loss, a second path loss and a third path loss, the first path loss is the path loss between the first AP and the target terminal, and the second path loss is the second AP and the target terminal
  • the third path loss is the path loss between the first AP and the second AP.
  • the target terminal may be any terminal associated with the first AP.
  • the target terminal may be a user terminal in the WLAN, or may also be a test terminal set in the WLAN and dedicated to identifying the network topology, which is not limited in this embodiment of the present application.
  • the path loss between the AP and the target terminal may refer to the path loss of the downlink between the AP and the target terminal; or, it may refer to the path of the uplink between the AP and the target terminal loss; alternatively, the path loss between the AP and the target terminal may include a downlink path loss and an uplink path loss.
  • the neighbor AP of the first AP may refer to an AP whose signal can be detected by the first AP, or an AP whose detected signal strength is greater than a certain threshold.
  • the first AP and its neighbor APs may be managed and controlled by the same AC, or may be managed and controlled by different ACs, which are not limited in this embodiment of the present application.
  • the network topology between the first AP, the second AP and the target terminal determined by the controller may refer to a set of path losses.
  • the set of path losses includes not only the path loss between the first AP and the second AP, but also the path loss between the AP and the terminal, that is, the path loss determined by the solution provided in the embodiment of the present application
  • the network topology is a three-dimensional (3-dimension, 3D) three-dimensional network topology.
  • the network topology can comprehensively and truly reflect the propagation of signals in space and the influence of signals on terminals and APs.
  • the path loss between the AP and the terminal can accurately reflect the signal transmission performance of the link between the AP and the terminal, and can accurately reflect the degree of interference between downlink signals sent by different APs.
  • the reliability of the 3D network topology is high, and radio frequency tuning based on the 3D network topology can better adapt to the complex and changeable space environment, and improve the environmental generalization of the radio frequency tuning algorithm.
  • FIG. 8 is a flowchart of a method for identifying a network topology provided by an embodiment of the present application, and the method may be applied to the wireless communication system as shown in FIG. 1 or FIG. 2 . Since the path loss of the downlink between the AP and the terminal is an important factor affecting the service experience of the terminal, the following description takes the path loss between the AP and the terminal as the path loss of the downlink as an example. Referring to Figure 8, the method may include:
  • Step 101 The controller sends an intensity measurement instruction for the target terminal to the first AP.
  • the target terminal is associated with the first AP, and the strength measurement instruction can be used to instruct the first AP to obtain a first received signal strength, where the first received signal strength refers to the strength of the measurement frame sent by the first AP detected by the target terminal, That is, the received signal strength of the downlink between the first AP and the target terminal.
  • the strength measurement instruction for the target terminal may carry the identifier of the target terminal, for example, may carry the MAC address of the target terminal.
  • Step 102 The first AP sends a first measurement frame to the target terminal.
  • the first AP may send the first measurement frame to the target terminal based on the intensity measurement instruction.
  • the first measurement frame may carry the BSSID of the first AP, and the BSSID may be the MAC address of the first AP.
  • the first measurement frame is a WLAN frame, for example, the first measurement frame may be a link measurement request frame, and the link measurement request frame may be used to request a received signal strength indicator (received signal strength indicator) indicator, RSSI).
  • AP1 may send the first measurement frame to STA1.
  • Step 103 The first AP sends a measurement request to the second AP.
  • the strength measurement instruction received by the first AP may also be used to instruct the first AP to acquire the second received signal strength.
  • the second received signal strength refers to the strength of the measurement frame sent by the second AP detected by the target terminal, that is, the received signal strength of the downlink between the second AP and the target terminal, and the second AP is the signal strength of the first AP. neighbor AP.
  • the strength measurement instruction may include the identifier of the second AP (eg, the MAC address of the second AP), and the first AP may send a measurement request to the second AP based on the strength measurement instruction.
  • the measurement request may include the BSSID of the first AP and the channel used by the first AP to associate with the target terminal. The measurement request is used to instruct the second AP to disguise as the first AP and send the second measurement frame to the target terminal.
  • AP1 may send a measurement request to AP2.
  • the controller may directly send a strength measurement instruction for the target terminal to the second AP, where the strength measurement instruction may include the BSSID of the first AP and the information used when the first AP associates with the target terminal. channel used.
  • the strength measurement instruction sent to the second AP may be used to instruct the second AP to disguise as the first AP and send the second measurement frame to the target terminal.
  • the BSSID of the first AP and the channel used by the first AP to associate with the target terminal are pre-stored in the second AP.
  • the second AP can disguise as the first AP and send the second measurement frame to the target terminal based on pre-stored information.
  • Step 104 The second AP sends the second measurement frame to the target terminal.
  • the second AP may send the second measurement frame to the target terminal.
  • the second measurement frame carries the BSSID of the first AP, and the channel used by the second AP to send the second measurement frame is the channel used by the first AP to associate with the target terminal (hereinafter referred to as the target channel) . Therefore, the second AP can disguise as the first AP and send the second measurement frame to the target terminal, so as to ensure that the second measurement frame can be received by the target terminal.
  • AP2 may send a second measurement frame to STA1 based on the measurement request sent by AP1.
  • the second AP does not need to switch channels. If the current working channel of the second AP is different from the target channel, the second AP may temporarily switch to the target channel to send the second measurement frame. Moreover, after the second AP finishes sending the second measurement frame through the target channel, it can immediately switch back to the original working channel to avoid affecting other services of the second AP.
  • Step 105 The target terminal sends a first measurement response frame to the first AP.
  • the target terminal may acquire the BSSID of the first AP from the first measurement frame, and feed back the first measurement response frame to the first AP based on the BSSID.
  • the first measurement response frame includes the strength of the first measurement frame detected by the target terminal, that is, the first received signal strength. For example, referring to FIG. 9, STA1 may send a first measurement response frame to AP1.
  • Step 106 The target terminal sends a second measurement response frame to the first AP.
  • the target terminal After the target terminal receives the second measurement frame sent by the second AP, since the BSSID carried in the second measurement frame is the BSSID of the first AP, the target terminal can feed back the second measurement frame to the first AP based on the BSSID of the first AP. Measurement response frame.
  • the second measurement response frame includes the strength of the second measurement frame detected by the target terminal, that is, the second received signal strength. For example, referring to FIG. 10 , after receiving the second measurement frame sent by AP2, STA2 may send a second measurement response frame to AP1.
  • the measurement response frame fed back by the target terminal to the first AP may be a link measurement report (link measurement request) frame.
  • both the first received signal strength and the second received signal strength may be represented by RSSI.
  • the controller may obtain the downlink information between each neighbor AP and the target terminal. Received signal strength. That is, each neighbor AP of the first AP may, under the instruction of the strength measurement instruction sent by the controller or the measurement request sent by the first AP, disguise as the first AP and send the measurement frame to the target terminal.
  • the target terminal may feed back a measurement response frame for the measurement frame sent by each neighbor AP to the first AP.
  • the controller may only consider the distance between the first AP and the first AP. Neighbor APs with smaller path loss. Therefore, on the premise of ensuring the reliability of the identified network topology, the calculation amount of the network topology identification process can be effectively reduced, and the identification efficiency of the network topology can be improved.
  • the controller may sort the multiple neighbors of the first AP in ascending order of path loss with the first AP, and determine the neighbor APs whose order number is less than or equal to N as the neighbor APs to be scanned . After that, the controller can acquire the received signal strength of the downlink between each neighbor AP to be scanned and the target terminal. That is, among the multiple neighbor APs of the first AP, the neighbor AP that only needs to be scanned may disguise as the first AP under the instruction of the intensity measurement instruction sent by the controller or the measurement request sent by the first AP to send to the target terminal. Measurement frame.
  • the target terminal may feed back to the first AP a measurement response frame for the measurement frame sent by each neighbor AP to be scanned.
  • the second AP belongs to the neighbor AP to be scanned, that is, the sequence number of the second AP is less than or equal to N.
  • N is a positive integer less than or equal to the total number of the multiple neighbor APs.
  • N when the total number of neighbor APs of the first AP is greater than the number threshold, that is, when the number of neighbor APs is large, N may be smaller than the total number of the multiple neighbor APs.
  • N When the total number of neighbor APs of the first AP is not greater than the number threshold, that is, when the number of neighbor APs is small, N may be equal to the total number of the multiple neighbor APs.
  • the controller may determine the top 10 neighbor APs with the smallest path loss with the first AP as the neighbor APs to be scanned, and may include in the strength measurement instruction sent to the first AP Carry the MAC addresses of the 10 neighbor APs.
  • the first AP may further send measurement requests to the 10 neighbor APs based on the strength measurement instruction.
  • Step 107 The first AP sends the first received signal strength and the second received signal strength to the controller.
  • the first AP may acquire the first received signal strength from the first measurement response frame, and send the first received signal strength to the controller.
  • the first AP can acquire the second received signal strength from the second measurement response frame, and send the second received signal strength to the controller.
  • the method shown in the above steps 101 to 107 can be used to obtain the first AP and the terminal.
  • the first AP may send the first measurement information and the second measurement information to the controller, respectively.
  • the first measurement information is measurement information obtained by the first AP measuring its associated terminal (for example, a target terminal), and the second measurement information refers to measurement information obtained by the second AP disguised as the first AP to send measurement frames Information.
  • the first measurement information may include, in addition to the above-mentioned first received signal strength, the identification of the terminal (for example, the MAC address), and information such as the BSSID of the first AP.
  • the second measurement information may also include information such as the identity of the terminal, the BSSID of the first AP, and the BSSID of the second AP.
  • FIG. 11 is a schematic diagram of first measurement information provided by an embodiment of the present application.
  • the first measurement information reported by the first AP to the controller may include the following fields: sta_mac, dl_rssi, dl_linkmargin, sta_tx_power, ul_rssi, tx_rate, rx_rate, radio_id, bssid, ssid, assoc_timestamp, online_time.
  • the field type of the sta_mac field is byte type, the length is 6 bytes, the field identifier (ID) is 1, and the sta_mac field is used to carry the MAC address of the terminal (for example, the target terminal).
  • the field type of the dl_rssi field is character (char) type, the length is 1 byte, and the field ID is 2.
  • the dl_rssi field is used to carry the downlink (downlink, DL) between the first AP detected by the terminal and the terminal.
  • the received signal strength such as the above-mentioned first received signal strength.
  • the received signal strength of the downlink can be represented by RSSI.
  • the field type of the dl_linkmargin field is char type, the length is 1 byte, and the field ID is 3.
  • the dl_linkmargin field is used to carry the first AP measured based on the transmission power control request (TPC request; transmit power control, TPC) frame.
  • TPC request transmission power control request
  • TPC transmit power control
  • LM link margin
  • the field type of the sta_tx_power field is an 8-bit unsigned integer (unit8), the length is 1 byte, and the field ID is 4.
  • the sta_tx_power field is used to carry the power (power) used by the terminal when sending the measurement response frame.
  • the sta_tx_power field may carry the power used by the target terminal to send the first measurement response frame. It can be understood that the power carried in the sta_tx_power field is reported by the terminal to the first AP.
  • the field type of the ul_rssi field is char type, the length is 1 byte, and the field ID is 5.
  • the ul_rssi field is used to carry the uplink (uplink, UP) data detected by the first AP between the first AP and the terminal.
  • the received signal strength that is, the strength of the signal sent by the terminal detected by the first AP.
  • the received signal strength of the uplink can also be represented by RSSI.
  • the field type of the tx_rate field is a 32-bit unsigned integer (unit32), the length is 4 bytes, and the field ID is 6.
  • the tx_rate field is used to carry the rate (rate) of the transmit (transmit, TX) link of the first AP. , and the rate is in megabits per second (Mbps).
  • the field type of the rx_rate field is unit32, the length is 4 bytes, and the field ID is 7.
  • the tx_rate field is used to carry the rate of the receive (receive, RX) link of the first AP, and the unit of the rate is Mbps.
  • the TX link of the first AP is the downlink between the first AP and the terminal, and the RX link is the uplink between the first AP and the terminal.
  • the field type of the radio_id field is unit8, the length is 1 byte, and the field ID is 8.
  • the tx_rate field is used to carry the ID of the radio frequency (radio) frequency band that the first AP is currently working on.
  • the radio frequency band in which the first AP works may be the 2.4GHz frequency band or the 5GHz frequency band.
  • the field type of the bssid field is byte type, the length is 6 bytes, and the field ID is 9.
  • the bssid field is used to carry the BSSID of the first AP.
  • the field type of the ssid field is a string type, the length is 32+1 bytes, and the field ID is 10.
  • the ssid field is used to carry the SSID of the first AP.
  • 32+1 bytes means that the first 32 bytes are used to carry the SSID, and the last byte is used to carry the terminator.
  • the field type of the assoc_timestamp field is unit32, the length is 4 bytes, and the field ID is 11.
  • the assoc_timestamp field is used to carry the AP to which the terminal accesses its associated (associate, assoc), that is, the timestamp (timestamp) of the first AP. .
  • the field type of the online_time field is unit32, the length is 4 bytes, and the field ID is 12.
  • the online_time field is used to carry the online (online) duration of the terminal, that is, the duration that the terminal has accessed the first AP.
  • FIG. 12 is a schematic diagram of second measurement information sent by a first AP to a controller according to an embodiment of the present application.
  • the second measurement information may include fields such as sta_mac, radio_id, assoc_bssid, assoc_ssid, assoc_dl_val, expected_neighbor_num, neighbor_num, neighbor_bssid_1, and neighbor_dl_val_1.
  • the field type of the sta_mac field is byte type, the length is 6 bytes, and the field ID is 1, and the sta_mac field is used to carry the MAC address of the terminal.
  • the field type of the radio_id field is unit8, the length is 1 byte, and the field ID is 2, and the radio_id field is used to carry the ID of the radio frequency band in which the first AP is currently working.
  • the field type of the assoc_bssid field is byte type, the length is 6 bytes, and the field ID is 3.
  • the assoc_bssid field is used to carry the BSSID of the first AP. It can be understood that, since the first AP is an AP associated with the target terminal, it can also be referred to as an associated AP.
  • the field type of the assoc_ssid field is string, the length is 32+1 bytes, and the field ID is 4.
  • the assoc_bssid field is used to carry the SSID of the first AP.
  • the field type of the assoc_dl_val field is char type, the length is 1 byte, and the field ID is 5.
  • the assoc_dl_val field is used to carry the received signal strength of the downlink between the first AP and the terminal.
  • the expected_neighbor_num field has a field type of unit8, a length of 1 byte, and a field ID of 10.
  • the expected_neighbor_num field is used to carry the expected number of neighbor APs to be scanned.
  • the number of neighbor APs to be scanned may refer to the number of neighbor APs for which the first AP sends a measurement request based on the strength measurement instruction. For example, if the controller instructs to obtain the received signal strength of the downlink between each neighbor AP and the target terminal, the first AP can send a measurement request to each neighbor AP, and accordingly, the desired scanning neighbor AP's The number is the total number of neighbor APs included in the first AP. If the controller instructs to acquire only the downlink received signal strengths between the N neighbor APs to be scanned and the target terminal, the first AP may only send a measurement request to the N neighbor APs to be scanned. The number of scanned neighbor APs is N.
  • the field type of the neighbor_num field is unit8, the length is 1 byte, and the field ID is 6.
  • the neighbor_num field is used to carry the number of valid neighbor APs within a measurement period (for example, 1 second).
  • the valid neighbor AP refers to a neighbor AP that sends a measurement frame to the terminal after receiving the measurement request sent by the first AP. It is understandable that after the first AP sends a measurement request to the neighbor AP, some neighbor APs may not respond to the measurement request due to factors such as the inability to switch channels, that is, the neighbor AP does not send measurement frames to the terminal, thus causing the first AP to fail to respond to the measurement request. The AP cannot obtain the received signal strength of the downlink between the neighbor AP and the terminal. Therefore, in this embodiment of the present application, the first AP may also report the number of valid neighbor APs to the controller.
  • the field type of the neighbor_bssid field is byte type, the length is 6 bytes, and the field ID is 7.
  • the neighbor_bssid field is used to carry the BSSID of the neighbor AP (eg, the second AP) of the first AP.
  • the field type of the neighbor_dl_val field is char type, the length is 1 byte, and the field ID is 8.
  • the neighbor_dl_val field is used to carry the received signal strength of the downlink between the neighbor AP and the terminal, for example, it can carry the above-mentioned second received signal strength .
  • the first AP can obtain the received signal strengths of the terminal to the multiple neighbor APs. Therefore, as a possible example, if the first AP receives the received signal strengths of multiple neighbor APs fed back by the terminal within one measurement period, the second measurement information may include multiple neighbor_bssid fields and multiple neighbor_dl_val fields, Each neighbor_bssid field may carry a BSSID of a neighbor AP, and each neighbor_dl_val field may carry a downlink received signal strength between a neighbor AP and a terminal.
  • the second measurement information may carry the BSSID of one neighbor AP, and the BSSID of one neighbor AP and the neighbor AP.
  • the received signal strength of the downlink between the target terminals, and the first AP may report multiple pieces of second measurement information to the controller in stages.
  • the first AP may send a measurement frame to the target terminal every first measurement period (for example, 1 second).
  • the target terminal can feed back the first measurement response frame within a time period much shorter than the first time period (for example, within a few milliseconds), so the first AP can send the first measurement response frame to the controller every first measurement period.
  • - Measurement information for example, 1 second.
  • the neighbor AP may need to switch the working channel to send the second measurement frame after receiving the measurement request or the strength measurement instruction, that is, the time required for the second AP to send the measurement frame is longer, so the first AP The time required to receive the second received signal strength is also longer.
  • the first AP may send the second measurement information to the controller every second measurement period.
  • the duration of the second measurement period may be greater than or equal to the duration of the first measurement period.
  • the duration of the second measurement period may be 1 to 10 seconds.
  • Step 108 The first AP sends the third received signal strength to the controller.
  • the third received signal strength refers to the strength of the measurement frame detected by the first AP and sent by the second AP, and the third received signal strength may also be represented by RSSI.
  • the controller may also periodically send an intensity detection instruction to each AP under its control according to a preset detection period.
  • the AP that has received the strength detection instruction can send a measurement frame to the neighbor AP, and the neighbor AP can then detect the strength of the measurement frame it has received, and report the detected strength to the controller.
  • the duration of the detection period may be 1 day.
  • the controller may send an intensity detection instruction to the first AP and the second AP in the early morning of each day, the second AP may send a measurement frame to the first AP based on the intensity detection instruction, and the first AP may detect the received measurement frame. strength, that is, the third received signal strength, and the third received signal strength is reported to the controller.
  • Step 109 The controller determines the network topology among the first AP, the second AP and the target terminal based on the first received signal strength, the second received signal strength and the third received signal strength.
  • the network topology includes: a first path loss, a second path loss, and a third path loss.
  • the first path loss is the path loss between the first AP and the target terminal
  • the second path loss is the path loss between the second AP and the target terminal
  • the third path loss is the difference between the first AP and the second AP path loss between.
  • the controller may determine a first path loss based on the first received signal strength, a second path loss based on the second received signal strength, and a third path loss based on the third received signal strength.
  • the first path loss is equal to the difference between the transmit power of the first AP and the first received signal strength
  • the second path loss is equal to the difference between the transmit power of the second AP and the second received signal strength
  • the first The three path loss is equal to the difference between the transmit power of the first AP and the strength of the third received signal.
  • the controller is an AC
  • the transmit power of the first AP and the second AP are both controlled by the AC
  • the AC stores the transmit power of each AP.
  • the controller is a server independent of the AC, the server can obtain the transmit power of each AP sent by the AC, or can obtain the transmit power reported by each AP.
  • the controller can obtain the downlink received signal strength between each neighbor AP and the target terminal.
  • the controller may determine the network topology among the first AP, multiple neighbor APs and the target terminal. That is, the network topology includes the first path loss, the path loss between each neighbor AP and the target terminal, and the path loss between the first AP and each neighbor AP.
  • the controller may determine N neighbor APs to be scanned from the plurality of neighbor APs, and the controller can obtain the downlink between each neighbor AP to be scanned and the target terminal the received signal strength.
  • the controller may determine the network topology among the first AP, the N neighbor APs to be scanned, and the target terminal. That is, the network topology includes the first path loss, the path loss between each neighbor AP to be scanned and the target terminal, and the path loss between the first AP and each neighbor AP to be scanned.
  • the controller determines each AP and the target terminal based on the received signal strength reported by the first AP.
  • the path loss between can be as shown in Table 1. Referring to Table 1, it can be seen that the identifier of the first AP is N1_5F_1, and the received signal strength (ie, the first received signal strength) of the target terminal to the first AP is -50 decibel milliwatts (dBm). Assuming that the transmit power of the first AP is 5dBm, the controller may determine that the first path loss of the downlink between the first AP and the target terminal is 55dBm.
  • the identifier of the second AP is N1_5F_13, and the received signal strength (ie, the second received signal strength) of the target terminal to the second AP is -60 dBm. Assuming that the transmit power of the second AP is 5dBm, the controller may determine that the second path loss of the downlink between the second AP and the target terminal is 65dBm.
  • the identifier of the third AP is N1_5F_26, and the received signal strength of the third AP by the target terminal is -65dBm. Assuming that the transmit power of the third AP is 5dBm, the controller may determine that the downlink path loss between the third AP and the target terminal is 70dBm.
  • the first AP can be associated with multiple terminals including the target terminal, and for each terminal, the controller can obtain the path loss between the terminal and the first AP, as well as the path loss between the terminal and each terminal. path loss between neighboring APs. Therefore, the controller can determine the network topology among the first AP, multiple neighbor APs of the first AP, and multiple terminals associated with the first AP. That is, the network topology determined by the controller may include: the first path loss, the path loss between each neighbor AP of the first AP and each terminal associated with the first AP, and the first AP and each neighbor Path loss between APs.
  • Step 110 The controller determines the AP with the smallest path loss between the first AP and multiple neighboring APs of the first AP and the target terminal as the home AP to which the target terminal belongs.
  • the controller may further determine the AP with the smallest path loss between the first AP and multiple neighbor APs and the target terminal as the target terminal.
  • the home AP to which the target terminal belongs refers to the AP with the smallest path loss with the target terminal. It can be understood that, on the premise that there is no obstruction between the target terminal and each AP, the home AP of the target terminal is the AP that is closest to the target terminal. It can also be understood that the home AP is not the same as the associated AP associated with the target terminal. Correspondingly, for the home AP, the terminal associated with the home AP is not the same as the terminal belonging to the home AP.
  • a terminal belonging to the home AP refers to a terminal that should be associated with the home AP under ideal conditions.
  • the controller may determine AP1 as the home AP to which the STA1 belongs, that is, both the home AP and the associated AP of STA1 are AP1.
  • the controller may determine AP1 as the home AP to which the STA2 belongs, that is, the home AP of STA2 and the associated AP are different APs.
  • the controller may determine the home AP to which the terminal belongs based on the method shown in step 110 above.
  • Step 111 The controller determines the ideal coverage of the home AP based on the terminal belonging to the home AP.
  • the controller After the controller determines the home AP to which the target terminal belongs, it can also determine the ideal coverage of the home AP based on the terminal belonging to the home AP, that is, the area where the terminal belonging to the home AP is located can be determined as the home AP ideal coverage.
  • the ideal coverage of an AP may refer to a coverage that can not only ensure the communication quality requirements of terminals located within the range, but also avoid interference of downlink signals between APs. It can be understood that the ideal coverage range determined by the controller based on the path loss between the terminal and the AP is a stable range, and the ideal coverage range will not change with the change of the transmit power of the AP.
  • the area where each terminal associated with an AP is located may be referred to as the actual coverage of the AP, and the actual coverage is not fixed, but is related to the transmit power of the AP. For example, if the transmit power of an AP is high, a terminal that is far away from the AP can also associate with the AP, and the actual coverage of the AP is also larger. On the contrary, if the transmit power of the AP is low, only the terminals that are close to the AP can associate with the AP, and the actual coverage of the AP is also smaller. 13, if the transmit power of AP2 is greater than the transmit power of AP1, not only STA3 and STA4 belonging to AP2 will be associated with AP2, but STA2 belonging to AP1 will also be associated with AP2.
  • the AP needs to provide a large transmit power to ensure that the received signal strength of the terminal meets the requirements of communication quality. Therefore, not only the power consumption of the AP is relatively high, but also the interference to other APs is relatively large.
  • the ideal coverage of the AP determined by the controller may be used for radio frequency tuning.
  • the controller may adjust the transmit power of the AP based on this ideal coverage so that the AP can associate with terminals located within its ideal coverage but not with terminals located outside its ideal coverage, that is, The actual coverage of the AP can be adjusted to be the same range as the ideal coverage of the AP. Therefore, it can be ensured that the AP can provide the terminal with a network access service based on the principle of the nearest service, that is, the terminal can associate with the AP with the smallest path loss.
  • the AP does not need high transmit power to make the received signal strength of the terminal meet the requirements of communication quality, that is, it can avoid the problem caused by the excessive power of the AP on the premise of ensuring the signal coverage quality of the AP. interference.
  • the first AP can report the received signal strength detected by its associated terminal.
  • the controller can separately count the terminal measurement data of each AP with the AP as the granularity.
  • the terminal measurement data of the first AP may include: the path loss between the first AP and each terminal associated with it, and the path loss between the neighbor AP and each of the foregoing terminals.
  • the controller may further adjust the terminal measurement data of the AP recorded by the controller based on the ideal coverage.
  • the adjusted terminal measurement data of the first AP may include: the path loss between the first AP and each terminal located within the ideal coverage of the first AP, and the neighbor AP and each of the above-mentioned path losses. Path loss between terminals.
  • the controller can delete the path loss between each AP and the terminal from the terminal measurement data of the associated AP (this deletion operation is also called de-sticking). ), and add the path loss between each AP and the terminal to the terminal measurement data of the home AP (this adding operation is also called viscosity supplementation).
  • the controller can delete the path loss between each AP and STA2 from the terminal measurement data of AP2, and delete the path loss between each AP and STA2.
  • the loss is added to the terminal measurement data of AP1.
  • Step 112 The controller identifies whether any one of the first AP and the second AP is a high-hanging AP.
  • the controller may determine whether the any AP is a high-hanging AP based on the path loss between the any AP and multiple terminals.
  • a high-hanging AP refers to an AP whose distance to multiple terminals is greater than the distance threshold, or that there are obstructions between multiple terminals.
  • the high-mounted AP may include an AP disposed on a higher roof, or, referring to FIG. 5( b ), an AP disposed between a roof and a ceiling (or suspended ceiling).
  • the multiple terminals may refer to terminals within the ideal coverage of any AP.
  • the controller may determine that any AP is a high-hanging AP when detecting that the path loss between any AP and a terminal located within the ideal coverage of the any AP is greater than the first loss threshold.
  • the multiple terminals may refer to terminals associated with any AP.
  • the controller may determine that any AP is a high-hanging AP when detecting that the path loss between any AP and each terminal associated with it is greater than the first loss threshold.
  • the first loss threshold may be a fixed value preconfigured in the controller, for example, may be a fixed value input in the controller according to expert experience, or the loss threshold calculated by the controller according to real-time data and/or historical data of the network environment .
  • the controller can determine that the distance between the deployment location of the AP and the distribution plane of the terminals is relatively far, or the distance from the distribution plane of the terminals is relatively large. There is an obstruction between the planes, so it can be determined that any AP is a high-hanging AP.
  • the controller identifies an AP as a high-hanging AP, it can determine that the path loss between the AP and the terminal is relatively large.
  • the transmit power of the high-mounted AP can be adjusted to be higher to ensure that the terminal (which may refer to the terminal associated with the high-mounted AP, or the ideal coverage of the high-mounted AP) The received signal strength of the terminal within the range) can meet the requirements of communication quality.
  • Step 113 The controller determines whether there is an obstruction between the first AP and the second AP.
  • the controller may further determine whether there is an obstruction between the first AP and the second AP based on the network topology between the first AP, the second AP, and the target terminal. It can be understood that the occlusion between APs can also be used as a basis for subsequent radio frequency tuning of APs, so as to improve the reliability of radio frequency tuning.
  • the controller determines that the path loss between the first AP and the terminal located in the ideal coverage of the first AP is less than the second loss threshold, the ideal distance between the second AP and the terminal located in the first AP is less than the second loss threshold. If the path loss between terminals within the coverage area is less than the second loss threshold, and the third path loss between the first AP and the second AP is greater than the third loss threshold, it can be determined that the distance between the first AP and the second AP is greater than the third loss threshold. Obstruction is present.
  • the controller determines that the path loss between the first AP and the terminal associated with the first AP is less than the second loss threshold, the path loss between the second AP and the terminal associated with the first AP is less than The second loss threshold, and the third path loss between the first AP and the second AP is greater than the third loss threshold, it may be determined that there is an obstruction between the first AP and the second AP.
  • the controller can determine that the path loss between each of the two APs and the terminal is relatively small, but the path loss between the two APs is relatively large. There are obstructions between APs.
  • the above-mentioned second loss threshold and third loss threshold are fixed values pre-configured in the controller, for example, can be fixed values input in the controller according to expert experience or the controller can be based on real-time data and data of the network environment. / or historical data to calculate the loss threshold.
  • the second loss threshold and the third loss threshold may be equal or unequal.
  • the controller determines that the path loss between the first AP and the terminal located in the ideal coverage of the first AP is less than the second loss threshold, the second AP and the terminal located in the ideal coverage of the first AP are within the ideal coverage of the first AP.
  • the path loss between the terminals is also less than the second loss threshold, and the third path loss between the first AP and the second AP is not greater than the third loss threshold, then it can be determined that there is no difference between the first AP and the second AP. Obstruction is present.
  • the controller determines that the path loss between the first AP and the terminal located in the ideal coverage area of the first AP is less than the second loss threshold, the path loss between the second AP and the terminal located in the ideal coverage area of the first AP is less than the second loss threshold. If the path loss is not less than the second loss threshold, and the third path loss between the first AP and the second AP is greater than the third loss threshold, it can also be determined that there is no obstruction between the first AP and the second AP.
  • Step 114 The controller performs radio frequency tuning on at least one of the first AP and the second AP based on the network topology among the first AP, the second AP and the target terminal.
  • the radio frequency tuning may include adjusting the transmit power of the AP, and/or adjusting the channel of the AP.
  • the controller may, based on the path loss between the any AP and a terminal located within the ideal coverage of the any AP, Adjust the transmit power of any AP, so that the signal strength (that is, the received signal strength of the downlink) of the signal sent by the AP detected by the terminal located in the ideal coverage of the AP is greater than the strength threshold, so as to It is ensured that the received signal strength of terminals within the ideal coverage of any AP can meet the requirements of communication quality.
  • the strength threshold may be a fixed value preconfigured in the controller, and the strength threshold may be determined empirically, or may be calculated according to real-time data and/or historical data of the network environment. For example, the intensity threshold may be empirically determined -65dBm.
  • the controller may allocate a channel of the first frequency to the first AP and allocate a channel of the second frequency to the second AP based on the network topology.
  • the first frequency and the second frequency may satisfy the following conditions:
  • the controller can determine that each AP has less interference with terminals within the ideal coverage of the other AP, so the two APs can be allocated channels of the same frequency or similar frequencies.
  • the frequency difference between the first frequency and the second frequency may be smaller than the first frequency threshold, for example, the first frequency may be equal to the second frequency.
  • the controller can determine that the AP interferes greatly with terminals within the ideal coverage of another AP, and the frequencies of the channels of the two APs need to be staggered.
  • the frequency difference between the first frequency and the second frequency may be greater than the second frequency threshold.
  • the controller determines based on the foregoing step 113 that there is no obstruction between the first AP and the second AP, and the path loss between the first AP and the second AP is relatively large (for example, greater than the third loss threshold), Then it can also be determined that the interference of each AP to the terminals within the ideal coverage of the other AP is small, so the two APs can be allocated channels with the same frequency or similar frequencies. That is, in this scenario, the frequency difference between the first frequency and the second frequency may also be smaller than the first frequency threshold.
  • fourth loss threshold, fifth loss threshold, first frequency threshold and second frequency threshold are all fixed values preconfigured in the controller. Also, the fourth loss threshold may be greater than or equal to the fifth loss threshold, and the first frequency threshold may be less than or equal to the second frequency threshold.
  • the controller can allocate a channel with the same or similar frequency to the two APs when it is determined that the interference between the downlink signals of the two APs is small, and can determine the difference between the downlink signals of the two APs.
  • the interference is large, allocate channels of different frequencies to the two APs to avoid co-channel interference. Since the number of channels that can be allocated in the system is limited, based on the channel allocation method provided by the embodiments of the present application, it can be ensured that the co-channel interference of the entire system is small.
  • FIG. 14 is a flowchart of a method for generating a terminal portrait by a controller according to an embodiment of the present application. Referring to FIG. 14 , the method may include:
  • Step 115 The controller detects whether the terminal portrait of the target terminal is currently valid.
  • a terminal portrait of the target terminal may be pre-stored in the controller, and the terminal portrait may be used to indicate whether the target terminal currently has the ability to detect the received signal strength. Moreover, in order to ensure the timeliness of the terminal portrait, the terminal portrait has a certain valid duration. The controller may re-update the terminal portrait when it is determined that the valid duration of the terminal portrait has expired, that is, when the terminal portrait is determined to be invalid.
  • step 116 may be executed, and if the controller determines that the terminal portrait of the target terminal is valid, step 122 may be executed .
  • the controller may detect whether the terminal portrait of the target terminal is currently valid. Wherein, if the target terminal is a terminal newly connected to the network, that is, the target terminal is associated with the AP connected to the controller for the first time, the terminal portrait of the target terminal is not stored in the controller.
  • Step 116 The controller sends a detection instruction to the first AP.
  • the controller may send a detection instruction to the first AP.
  • the detection instruction may be used to instruct the first AP to trigger the target terminal to detect the received signal strength.
  • Step 117 The first AP sends a measurement frame to the target terminal.
  • the first AP may send a measurement frame to the target terminal based on the detection instruction. If the target terminal currently has the ability to detect received signal strength, after receiving the measurement frame, the target terminal may feed back a measurement response frame to the first AP, where the measurement response frame includes the received signal strength of the measurement frame detected by the target terminal. If the target terminal currently does not have the ability to detect the received signal strength, after receiving the measurement frame, the target terminal will not feed back a measurement response frame carrying the received signal strength to the first AP.
  • the current inability of the target terminal to detect the received signal strength may be caused by the following situations: 1.
  • the target terminal does not support the detection standard of the signal strength.
  • the target terminal supports the detection standard of signal strength, but currently cannot feed back measurement response frames due to factors such as the running state (for example, the screen is always off or in the power saving mode).
  • the detection standard of the signal strength may be the Institute of Electrical and Electronics Engineers (IEEE) 802.11k standard.
  • Step 118 The first AP sends the detection result to the controller based on the received signal strength fed back by the target terminal.
  • the first AP may send a detection result to the controller based on the received signal strength fed back by the target terminal, where the detection result is used to indicate whether the first AP has received the received signal strength fed back by the target terminal.
  • Step 119 The controller determines the detection success rate of the target terminal based on the detection result sent by the first AP within the first time period.
  • the controller may perform statistics on the detection results sent by the first AP within the first time period, so as to determine the detection success rate of the target terminal.
  • M1 is the number of target detection results received by the controller within the first period of time
  • M0 is the detection results received by the controller within the first period of time
  • the target detection result is used to indicate that the first AP receives the received signal strength fed back by the target terminal.
  • the first AP will send 200 detection results to the controller within the first time period.
  • the first period may be a period after the controller sends the detection instruction to the first AP.
  • the duration of the first period may be a fixed period preconfigured in the controller, for example, the first period may be 1 minute or 2 minutes.
  • the controller may calculate the detection success rate of the target terminal in a plurality of first time periods, and the controller may determine that the detection success rate tends to be stable after Then execute the following step 121.
  • that the detection success rate tends to be stable may refer to: the variation of the detection success rate of two adjacent first time periods is less than a threshold, for example, 5%.
  • the controller may also directly determine the detection success rate of the target terminal when it detects that the number of continuously received failed detection results is greater than or equal to the number threshold is 0.
  • the failure detection result is used to indicate that the first AP has not received the received signal strength fed back by the target terminal. For example, assuming that the number threshold is 100, if the first AP does not receive the measurement response frame fed back by the target terminal after continuously sending 100 measurement frames, the first AP will continuously send 100 failure detection results to the controller.
  • the controller may further determine that the detection success rate of the target terminal is 0.
  • Step 120 The controller processes the detection success rates of multiple terminals to obtain a success rate threshold.
  • the controller may further process the detection success rates of multiple terminals acquired within the third time period to determine a success rate threshold.
  • the third time period may be a time period before the first time period.
  • the third time period may partially overlap with the first time period, or may not overlap, which is not limited in this embodiment of the present application.
  • the controller may use a boxplot algorithm to process the detection success rates of the multiple terminals determined within the third time period to obtain the success rate threshold.
  • the principle of the boxplot algorithm is as follows: among the obtained large number of observations, the observations smaller than QL-1.5IQR or larger than QU+1.5IQR are determined as outliers.
  • QL is the lower quartile, which means that a quarter of all observations are smaller than QL.
  • QU is the upper quartile, which means that a quarter of all observations are larger than QU.
  • the detection success rate of the terminal acquired by the controller is the observation value
  • the controller can use the boxplot algorithm to process a large number of acquired detection success rates, and can use QL-1.5IQR as the success rate rate threshold.
  • the boxplot algorithm can truly and intuitively show the distribution of the observed values, and does not have restrictive requirements on the observed values (for example, it does not require the observed values to obey a normal distribution or approximately follow a normal distribution).
  • the criteria for judging outliers by the boxplot algorithm are based on quartiles and interquartile ranges. Since quartiles give some indication of the center, spread and shape of the distribution of observed values, it has certain robustness. , i.e. 25% of observations can go arbitrarily far without perturbing the quartiles greatly, so outliers generally cannot exert an influence on this criterion. In view of this, the result of identifying outliers by the boxplot is relatively objective, so the embodiment of the present application adopts the boxplot algorithm to determine the success rate threshold, so as to ensure the reliability of the success rate threshold.
  • the controller may also use the 3 ⁇ principle to process the detection success rates of multiple terminals to obtain a success rate threshold.
  • controller can also directly use a pre-configured fixed value as the success rate threshold.
  • Step 121 The controller generates a terminal portrait of the target terminal based on the detection success rate of the target terminal.
  • the terminal portrait of the target terminal can be used to indicate whether the target terminal has the ability to detect the received signal strength in the second time period after the current time, that is, the terminal portrait is valid in the second time period after the current time.
  • the controller may determine that the target terminal has the ability to detect the received signal strength in the second period after the current moment. If the detection success rate of the target terminal is less than the success rate threshold, the controller may determine that the target terminal does not have the ability to detect the received signal strength within the second time period after the current moment.
  • the duration of the second period may be a fixed duration preconfigured in the controller, for example, the second duration may be three months.
  • Step 122 The controller determines, based on the terminal portrait of the target terminal, whether the target terminal currently has the ability to detect the received signal strength.
  • the controller determines that the terminal portrait of the target terminal is valid, it can judge whether the target terminal currently has the ability to detect the received signal strength based on the terminal portrait of the target terminal. If the controller determines based on the terminal portrait that the target terminal currently does not have the ability to detect the received signal strength, the operation can be ended, that is, the controller does not need to start measuring the target terminal. If the controller determines based on the terminal portrait that the target terminal currently has the ability to detect the received signal strength, the above step 101 may be performed. That is, the controller may send a strength measurement instruction for the target terminal to the first AP associated with the target terminal when it is determined that the target terminal currently has the ability to detect the received signal strength. In this way, when the target terminal does not have the ability to detect the received signal strength, the controller sends a strength measurement instruction to the first AP to avoid invalid measurement.
  • the terminal portraits of each terminal stored in the controller may be as shown in Table 2. If the target terminal is a terminal with a MAC address of 00:11:22:33:44:55 and the current time is 2020-11-30, the controller can determine that the target terminal currently has the ability to receive The detection capability of the signal strength can be performed, and the above step 101 can be performed. If the target terminal is a terminal whose MAC address is aa:bb:cc:dd:ee:ff, the controller can determine that the target terminal currently does not have the ability to detect the received signal strength based on the terminal portrait shown in Table 2, and can end operate.
  • the signal strength detection standard is the IEEE 802.11k standard
  • about 60%-70% of the terminals on the existing network support the 802.11k standard
  • the remaining 30%-40% of the terminals do not support the 802.11k standard.
  • the method provided by the embodiment of the present application starts the measurement after it is determined that the target terminal has the ability to detect the received signal strength, and theoretically, the air interface overhead of the downlink measurement can be reduced by at least 30%.
  • step 103 may be performed before step 102
  • step 108 may be performed before step 107
  • steps 110 and 111 may be deleted according to circumstances
  • any of steps 112 to 114 may be deleted according to circumstances
  • the execution order of each step in steps 112 to 114 may be adjusted according to circumstances.
  • the above embodiments are described by taking the path loss between the AP and the terminal as an example of the path loss of the downlink.
  • the path loss may also be the path loss of the uplink between the AP and the terminal, and the path loss of the uplink may be based on the transmit power of the terminal and the strength of the signal sent by the terminal detected by the AP (for example, the uplink RSSI) obtained.
  • the second AP if the second AP needs to detect the strength of the signal sent by the target terminal, the second AP can switch its working channel to the target channel (that is, the channel used when the first AP associates with the target terminal) to receive the signal sent by the target terminal. signal and detect the strength of the received signal.
  • the embodiment of the present application provides a method for identifying a network topology.
  • the network topology determined by the controller includes not only the path loss between two APs, but also the path loss between each AP and the terminal. That is, the network topology is a 3D network topology.
  • the path loss between the AP and the terminal can not only accurately reflect the signal transmission performance of the link between the AP and the terminal, but also accurately reflect the degree of interference between downlink signals sent by different APs.
  • the reliability of the network topology determined by the controller is high. Furthermore, it can ensure high reliability when the AP is managed and controlled (for example, radio frequency tuning) based on the network topology.
  • the controller can identify high-hanging APs and non-ideal deployment scenarios such as obstructions between APs. Therefore, it can ensure that radio frequency tuning based on the identified deployment scenarios can provide better signal quality for terminals. Lower disruption, and a better business experience.
  • the controller can determine the ideal coverage of the AP based on the path loss between the AP and the terminal, and can perform power tuning based on the ideal coverage. In this way, interference caused by excessive power of the AP can be avoided on the premise of ensuring the signal coverage quality of the AP.
  • the controller allocates channels to APs based on 3D network topology, which can effectively avoid co-channel interference.
  • the path loss between the AP and the terminal in the 3D network topology determined by the controller can be the path loss of the downlink. Since the path loss of the downlink is an important factor affecting the service experience of the terminal, based on the downlink path loss RF tuning based on the path loss of the channel can effectively improve the service experience of the terminal.
  • the controller can measure the terminal that currently has the signal strength detection capability based on the terminal portrait, thereby avoiding the waste of network resources due to invalid measurement.
  • FIG. 15 is a schematic structural diagram of a controller provided by an embodiment of the present application.
  • the controller can be applied to the system shown in FIG. 1 or FIG. 2 and can be used to realize the identification of the network topology provided by the above method embodiments. method.
  • the controller includes:
  • the first determining module 201 is configured to determine the network topology between the first access point AP, the second AP and the target terminal.
  • the target terminal is associated with a first AP
  • the second AP is a neighbor AP of the first AP
  • the network topology includes: a first path loss, a second path loss, and a third path loss
  • the first path loss is the first path loss.
  • the path loss between an AP and the target terminal, the second path loss is the path loss between the second AP and the target terminal, and the third path loss is the path loss between the first AP and the second AP.
  • step 109 For the functional implementation of the first determination module 201, reference may be made to the relevant description of step 109 in the foregoing method embodiment.
  • the first determining module 201 can also be configured to determine the AP with the smallest path loss between the first AP and the first AP's multiple neighbor APs and the target terminal as the target terminal's home. a home AP; and determining an ideal coverage of the home AP based on a terminal belonging to the home AP, where the ideal coverage of the home AP is used for radio frequency tuning.
  • first determination module 201 For the functional implementation of the first determination module 201, reference may also be made to the relevant descriptions of steps 110 and 111 in the above method embodiments.
  • the first determining module 201 may also be configured to: for any AP in the first AP and the second AP, determine the any AP based on the path loss between the AP and multiple terminals Whether the AP is a high-hanging AP, the high-hanging AP refers to an AP whose distance from the multiple terminals is greater than the distance threshold, or there are obstacles between the multiple terminals.
  • step 112 For the functional implementation of the first determination module 201, reference may also be made to the relevant description of step 112 in the above method embodiments.
  • the first determining module 201 may be configured to: if the path loss between the any AP and the terminal located in the ideal coverage of the any AP is greater than the first loss threshold, determine that the any AP is High hanging AP.
  • the first determining module 201 may be further configured to: if the path loss between the first AP and the terminal located in the ideal coverage of the first AP is less than the second loss threshold, the second AP and the terminal located in the ideal coverage The path loss between terminals within the ideal coverage area of the first AP is less than the second loss threshold, and the third path loss between the first AP and the second AP is greater than the third loss threshold, then determine the third loss threshold. There is an obstruction between an AP and the second AP.
  • step 113 For the functional implementation of the first determination module 201, reference may also be made to the relevant description of step 113 in the foregoing method embodiments.
  • the controller may further include:
  • the tuning module 202 is configured to perform radio frequency tuning on at least one of the first AP and the second AP based on the network topology between the first AP, the second AP and the target terminal.
  • the tuning module 202 For the function implementation of the tuning module 202, reference may be made to the relevant description of step 114 in the foregoing method embodiment.
  • the controller may further include:
  • the power adjustment module 203 is configured to, for any one of the first AP and the second AP, adjust the any AP based on the path loss between the any AP and a terminal located within the ideal coverage of the any AP.
  • the transmit power of an AP makes the signal strength of the signal sent by any AP detected by the terminal located in the ideal coverage of the AP is greater than the strength threshold.
  • step 114 For the function implementation of the power adjustment module 203, reference may be made to the relevant description of step 114 in the foregoing method embodiments.
  • the controller may further include:
  • the channel allocation module 204 is configured to allocate a channel of the first frequency to the first AP, and allocate a channel of the second frequency to the second AP. Wherein, if the path loss between the first AP and the terminal located in the ideal coverage of the second AP is greater than the fourth loss threshold, and the distance between the second AP and the terminal located in the ideal coverage of the first AP is greater than the fourth loss threshold The path loss between is greater than the fourth loss threshold, then the frequency difference between the first frequency and the second frequency is less than the first frequency threshold;
  • the path loss between the first AP and the terminal located in the ideal coverage area of the second AP is less than the fifth loss threshold, or, between the second AP and the terminal located in the ideal coverage area of the first AP If the path loss is less than the fifth loss threshold, the frequency difference between the first frequency and the second frequency is greater than the second frequency threshold; the fourth loss threshold is greater than or equal to the fifth loss threshold, and the first frequency threshold is less than or equal to the second frequency threshold.
  • channel allocation module 204 For the function implementation of the channel allocation module 204, reference may also be made to the relevant description of step 114 in the foregoing method embodiments.
  • the above-mentioned power adjustment module 203 and channel allocation module 204 can both be sub-modules in the optimization module 202 , that is, the optimization module 202 can implement the functions of the power adjustment module 203 and the channel allocation module 204 .
  • the controller may further include:
  • the receiving module 205 is configured to receive the first received signal strength and the second received signal strength sent by the first AP, where both the first received signal strength and the second received signal strength are sent by the target terminal to the first AP.
  • the first received signal strength is the strength of the first measurement frame sent by the first AP detected by the target terminal, the first measurement frame carries the BSSID of the first AP, and the first received signal strength is used to determine the first path loss
  • the second received signal strength is the strength of the second measurement frame sent by the second AP detected by the target terminal, the second measurement frame carries the BSSID of the first AP, and the second received signal Strength is used to determine this second path loss.
  • step 107 For the function implementation of the receiving module 205, reference may be made to the relevant description of step 107 in the foregoing method embodiments.
  • the controller may further include:
  • the sending module 206 is configured to send a detection instruction to the first AP before the receiving module 205 receives the first received signal strength and the second received signal strength sent by the first AP, where the detection instruction is used to instruct the first AP to trigger
  • the target terminal detects the received signal strength.
  • the second determination module 207 is configured to determine the detection success rate of the target terminal based on the detection result sent by the first AP within the first time period, and if the detection success rate is greater than or equal to the success rate threshold, determine the target terminal Have the ability to detect the received signal strength in the second period after the current moment, wherein the detection result is used to indicate whether the first AP has received the received signal strength fed back by the target terminal; the detection success rate is within the first The ratio of the number of target detection results received in the period to the total number of detection results received in the first period, where the target detection result is used to indicate that the first AP receives the received signal strength fed back by the target terminal.
  • step 118 For the function implementation of the second determination module 207, reference may be made to the relevant descriptions of step 118, step 119 and step 121 in the foregoing method embodiment.
  • the sending module 206 can also be configured to send, to the first AP, a strength measurement instruction for the target terminal based on the target terminal having the ability to detect the received signal strength, where the strength measurement instruction is used to instruct the first AP to obtain the first AP. a received signal strength and the second received signal strength.
  • the controller may further include:
  • the processing module 208 is configured to use the boxplot algorithm to process the detection success rates of the multiple terminals determined in the third time period to obtain the success rate threshold.
  • the processing module 208 reference may also be made to the relevant description of step 120 in the foregoing method embodiments.
  • the first AP has multiple neighbor APs including the second AP, and after the multiple neighbor APs are sorted in ascending order of path loss with the first AP, the second AP
  • the arrangement sequence number of the APs is less than or equal to N, where N is a positive integer less than or equal to the total number of the multiple neighbor APs.
  • an embodiment of the present application provides a controller, where the network topology determined by the controller includes not only the path loss between two APs, but also the path loss between each AP and the terminal, that is, the The network topology is a 3D network topology.
  • the path loss between the AP and the terminal can not only accurately reflect the signal transmission performance of the link between the AP and the terminal, but also accurately reflect the degree of interference between downlink signals sent by different APs.
  • the reliability of the network topology determined by the controller is high. Furthermore, it can ensure high reliability when the AP is managed and controlled (for example, radio frequency tuning) based on the network topology.
  • controller may be implemented by an application-specific integrated circuit (ASIC), or a programmable logic device (PLD), and the above-mentioned PLD may be a complex program logic Device (complex programmable logical device, CPLD), field-programmable gate array (field-programmable gate array, FPGA), general array logic (generic array logic, GAL) or any combination thereof.
  • ASIC application-specific integrated circuit
  • PLD programmable logic device
  • the method for identifying network topology provided by the above method embodiments may also be implemented by software.
  • each module in the above controller may also be a software module.
  • FIG. 17 is a schematic structural diagram of another controller provided by an embodiment of the present application, and the controller may be applied to the system shown in FIG. 1 or FIG. 2 .
  • the controller may include: a processor 301 , a memory 302 , a network interface 303 and a bus 304 .
  • the bus 304 is used for connecting the processor 301 , the memory 302 and the network interface 303 .
  • the communication connection with other devices can be realized through the network interface 303 (which may be wired or wireless).
  • the memory 302 stores a computer program 3021 for realizing various application functions.
  • the processor 301 may be a CPU, and the processor 301 may also be other general-purpose processors, digital signal processors (digital signal processing, DSP), application-specific integrated circuits (application-specific integrated circuits) , ASIC), field-programmable gate array (FPGA), generic array logic (GAL) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., or the above Any combination of processors.
  • DSP digital signal processing
  • ASIC application-specific integrated circuits
  • FPGA field-programmable gate array
  • GAL generic array logic
  • a general purpose processor may be a microprocessor or any conventional processor or the like.
  • Memory 302 may include volatile memory, non-volatile memory, or a combination thereof.
  • the non-volatile memory may include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable read-only memory (EPROM). Erase programmable read-only memory (electrically EPROM, EEPROM), flash memory, or any combination thereof.
  • Volatile memory may include random access memory (RAM), such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (double data date SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (synchlink DRAM, SLDRAM) ), direct rambus RAM (DR RAM), or any combination thereof.
  • RAM random access memory
  • SRAM static random access memory
  • DRAM dynamic random access memory
  • SDRAM synchronous dynamic random access memory
  • double data rate synchronous dynamic random access memory double data date SDRAM, DDR SDRAM
  • enhanced synchronous dynamic random access memory enhanced synchronous dynamic random access memory
  • synchronous link dynamic random access memory synchronous link dynamic random access memory
  • DR RAM direct rambus RAM
  • bus 304 may also include a power bus, a control bus, a status signal bus, and the like.
  • bus 304 may also include a power bus, a control bus, a status signal bus, and the like.
  • the various buses are labeled as bus 304 in the figure.
  • the processor 301 may be configured to execute the computer program 3021 stored in the memory 302 to implement the steps performed by the controller in the above method embodiments.
  • FIG. 18 is a schematic structural diagram of still another controller provided by an embodiment of the present application, and the controller may be applied to the system shown in FIG. 1 or FIG. 2 .
  • the controller includes a main control board 401 and an interface board 402 .
  • the main control board 401 is also called a main processing unit (MPU) or a route processor card (route processor card).
  • the main control board 401 is used to control and manage various components in the controller, including route calculation and device management. , equipment maintenance and protocol processing and other functions.
  • the main control board 401 includes: a central processing unit 4011 and a memory 4012 .
  • the interface board 402 is also referred to as a line processing unit (LPU), a line card (line card) or a service board.
  • the interface board 402 is used to provide various service interfaces and realize the forwarding of data packets.
  • the service interface includes, but is not limited to, an Ethernet interface, a SONET/SDH-based data packet (packet over SONET/SDH, POS) interface, and the like.
  • SONET refers to a synchronous optical network
  • SDH refers to a synchronous digital hierarchy.
  • the Ethernet interface is, for example, a flexible Ethernet service interface (flexible Ethernet clients, FlexE Clients).
  • the interface board 402 includes: a central processing unit 4021 , a network processor 4022 , a forwarding table entry memory 4024 and a physical interface card (PIC) 4023 .
  • PIC physical interface card
  • the central processing unit 4021 on the interface board 402 is used to control and manage the interface board 402 and communicate with the central processing unit 4011 on the main control board 401 .
  • the network processor 4022 is used to implement packet forwarding processing.
  • the form of the network processor 4022 may be a forwarding chip.
  • the forwarding chip may be a network processor (NP).
  • the forwarding chip may be implemented by an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA).
  • ASIC application-specific integrated circuit
  • FPGA field programmable gate array
  • the network processor 4022 is configured to forward the received message based on the forwarding table stored in the forwarding table entry memory 4024.
  • the message is sent to the CPU (eg The central processing unit 4021) processes; if the destination address of the message is not the address of the controller, find the next hop and outgoing interface corresponding to the destination address from the forwarding table according to the destination address, and forward the message to the destination The outbound interface corresponding to the address.
  • the processing of the uplink message may include: processing of the incoming interface of the message, and forwarding table lookup; the processing of the downlink message may include: forwarding table lookup, and so on.
  • the central processing unit can also perform the function of a forwarding chip, for example, software forwarding is implemented based on a general-purpose CPU, so that a forwarding chip is not required in the interface board.
  • the physical interface card 4023 is used to realize the interconnection function of the physical layer, through which the original traffic enters the interface board 402 and the processed packets are sent out from the physical interface card 4023 .
  • the physical interface card 4023 is also called a daughter card, which can be installed on the interface board 402, and is responsible for converting the photoelectric signal into a message, and after checking the validity of the message, it is forwarded to the network processor 4022 for processing.
  • the central processing unit 4021 can also perform the functions of the network processor 4022 , such as implementing software forwarding based on a general-purpose CPU, so that the network processor 4022 is not required in the physical interface card 4023 .
  • the controller includes a plurality of interface boards.
  • the controller further includes an interface board 403 .
  • the interface board 403 includes a central processing unit 4031 , a network processor 4032 , a forwarding table entry storage 4034 and a physical interface card 4033 .
  • the functions and implementation manners of the components in the interface board 403 are the same as or similar to those of the interface board 402 , and details are not described herein again.
  • the controller further includes a switch fabric board 404 .
  • the switch fabric 404 may also be referred to as a switch fabric unit (switch fabric unit, SFU).
  • SFU switch fabric unit
  • the switching network board 404 is used to complete data exchange between the interface boards.
  • the interface board 402 and the interface board 403 can communicate through the switch fabric board 404 .
  • the main control board 401 is coupled with the interface board.
  • the main control board 401 , the interface board 402 , the interface board 403 , and the switching network board 404 are connected to the system backplane through the system bus to realize intercommunication.
  • an inter-process communication (IPC) channel is established between the main control board 401, the interface board 402 and the interface board 403, and the main control board 401 and the interface board 402 and the interface board 403 The communication is carried out through the IPC channel.
  • IPC inter-process communication
  • the controller includes a control plane and a forwarding plane
  • the control plane includes the main control board 401 and the central processing unit 4011
  • the forwarding plane includes various components that perform forwarding, such as the forwarding entry memory 4024, the physical interface card 4023 and the network processor 4022.
  • the control plane performs functions such as routers, generating forwarding tables, processing signaling and protocol packets, and configuring and maintaining the status of network devices.
  • the control plane issues the generated forwarding tables to the forwarding plane.
  • the network processor 4022 controls the The following forwarding table forwards the packets received by the physical interface card 4023 by looking up the table.
  • the forwarding table issued by the control plane may be stored in the forwarding table entry storage 4024 . In some embodiments, the control plane and forwarding plane may be completely separated and not on the same network device.
  • main control boards there may be one or more main control boards, and when there are multiple main control boards, they may include the main main control board and the backup main control board.
  • the network management device can have at least one switching network board, and the switching network board realizes data exchange between multiple interface boards, providing large-capacity data exchange and processing capabilities. Therefore, the data access and processing capabilities of the network management device of the distributed architecture are greater than those of the network management device of the centralized architecture.
  • the network management device can also be in the form of only one board, that is, there is no switching network board, and the functions of the interface board and the main control board are integrated on this board.
  • the central processing unit on the control board can be combined into a central processing unit on this board to perform the superimposed functions of the two.
  • This form of network management equipment has low data exchange and processing capabilities (for example, low-end switches or routers and other network devices).
  • the specific architecture used depends on the specific networking deployment scenario, and there is no restriction here.
  • Embodiments of the present application further provide a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and the instructions are executed by a processor to implement the method for identifying a network topology provided by the foregoing method embodiments.
  • the embodiments of the present application also provide a computer program product containing instructions, when the computer program product runs on the computer, the computer program product enables the computer to execute the method for identifying the network topology provided by the above method embodiments.
  • the embodiment of the present application also provides a wireless communication system, as shown in FIG. 1 and FIG. 2 , the system includes: a controller 01, and a plurality of APs 02 connected to the controller 01.
  • the controller 01 may be the controller shown in any one of FIG. 15 to FIG. 17 .
  • the controller 01 may be AC.
  • the above embodiments may be implemented in whole or in part by software, hardware, firmware or any combination thereof.
  • the above-described embodiments may be implemented in whole or in part in the form of a computer program product.
  • the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated.
  • the computer may be a general purpose computer, special purpose computer, computer network, or other programmable device.
  • the computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transferred from a website mobile terminal, computer, server or data
  • the center transmits to another website mobile terminal, computer, server or data center through wired (such as coaxial cable, optical fiber, twisted pair) or wireless (such as infrared, wireless, microwave, etc.).
  • the computer-readable storage medium can be any medium that can be accessed by a computer, or a data storage device such as a server, a data center, or the like containing one or more medium sets.
  • the medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, an optical disk), or a semiconductor medium.
  • the semiconductor medium may be a solid state drive (SSD).

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Abstract

提供了一种网络拓扑的识别方法、装置及无线通信系统。控制器所确定的第一AP、第二AP和目标终端之间的网络拓扑不仅包括两个AP之间的路径损耗，还包括AP与终端之间的路径损耗。由于AP与终端之间的路径损耗不仅可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度，因此该网络拓扑的可靠性较高。进而，可以确保基于该网络拓扑对AP进行管控(例如射频调优)的效果较好。

Description

网络拓扑的识别方法、装置及无线通信系统
本申请要求于2021年4月9日提交的申请号为202110384890.0、发明名称为“网络拓扑的识别方法、装置及无线通信系统”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信领域，特别涉及一种网络拓扑的识别方法、装置及无线通信系统。
背景技术
瘦接入点(fit access point，FIT AP)是一种集中式的无线局域网(wireless local area networks，WLAN)架构，采用FIT AP架构的WLAN主要包括接入控制器(access controller，AC)、多个AP，以及至少一个站点(station，STA)。其中，AP能够为STA提供无线接入服务，AC能够对多个AP进行统一的管理和控制。
为了改善WLAN的系统性能，AC还能够基于AP之间的路径损耗(简称路损)确定AP之间的网络拓扑，进而基于该网络拓扑对各个AP进行管控。
在WLAN的实际部署场景中，若距离较近的两个AP之间存在遮挡物，则AC检测到的该两个AP之间的路损会较小，进而会确定该两个AP之间的距离较远。AC会将该两个AP的发射功率均调整的较高。但是，若该两个AP与STA之间均不存在遮挡，则会导致该两个AP的下行信号之间存在较为严重的干扰。基于上述分析可知，基于AP之间的路损所确定出的网络拓扑的可靠性较低。
发明内容
本申请提供了一种网络拓扑的识别方法、装置及无线通信系统，可以解决基于AP之间的路损所确定出的网络拓扑的可靠性较低的技术问题，技术方案如下：
一方面，提供了一种网络拓扑的识别方法，该方法包括：控制器确定第一AP、第二AP和目标终端之间的网络拓扑，其中，该目标终端与第一AP关联，该第二AP为第一AP的邻居AP，该网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗；该第一路径损耗是第一AP与目标终端之间的路径损耗，该第二路径损耗是第二AP与目标终端之间的路径损耗，该第三路径损耗是第一AP与第二AP之间的路径损耗。
本申请提供的方案中，控制器所确定的网络拓扑不仅包括两个AP之间的路径损耗，还包括AP与终端之间的路径损耗。由于AP与终端之间的路径损耗可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度，因此该网络拓扑的可靠性较高。进而，可以确保基于该网络拓扑对AP进行管控(例如射频调优)时的可靠性较高。
可选地，该方法还可以包括：将该第一AP和该第一AP的多个邻居AP中与目标终端之间的路径损耗最小的AP确定为该目标终端归属的归属AP；基于归属于该归属AP的终端确定该归属AP的理想覆盖范围。
该归属AP的理想覆盖范围可以用于进行射频调优，以使得位于该理想覆盖范围内的终端均能够与该归属AP关联。也即是，基于该理想覆盖范围进行射频调优，可以使得终端均能够 与路径损耗最小的AP关联。由此，可以确保AP不需要很高的发射功率即可使得终端的接收信号强度满足通信质量的需求，进而可以在保证AP的信号覆盖质量的前提下避免AP的功率过大而造成的干扰。
可选地，该方法还可以包括：对于第一AP和第二AP中的任一AP，基于该任一AP与多个终端之间的路径损耗，确定该任一AP是否为高挂AP，高挂AP是指与多个终端之间的距离大于距离阈值，或与多个终端之间存在遮挡物的AP。
控制器若识别出某个AP为高挂AP，则可以确定该AP与终端之间的路径损耗较大。相应的，在后续进行射频调优时，可以将该高挂AP的发射功率调节的较高，以确保终端的接收信号强度能够满足通信质量的需求。
可选地，该多个终端可以为位于任一AP的理想覆盖范围内的终端；基于任一AP与多个终端之间的路径损耗，确定任一AP是否为高挂AP的过程可以包括：若该任一AP与位于该任一AP的理想覆盖范围内的终端之间的路径损耗大于第一损耗阈值，则确定该任一AP为高挂AP。
若AP与其理想覆盖范围内的终端之间的路径损耗均较大，则控制器可以确定该AP的部署位置与终端的分布平面之间的距离较远，或者与终端的分布平面之间存在遮挡物，进而可以确定该任一AP为高挂AP。
可选地，该方法还可以包括：若第一AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，第二AP与位于第一AP的理想覆盖范围内的终端之间的路径损耗小于该第二损耗阈值，且第一AP与第二AP之间的第三路径损耗大于第三损耗阈值，则确定该第一AP和该第二AP之间存在遮挡物。
控制器所确定出的AP之间的遮挡情况也可以作为后续对AP进行射频调优时的依据，以提高射频调优的可靠性。
可选地，该方法还可以包括：基于该第一AP、该第二AP和该目标终端之间的网络拓扑，对该第一AP和该第二AP中的至少一个AP进行射频调优。
由于控制器所确定出的网络拓扑还能够反映AP与终端之间的信号传输性能，因此基于该网络拓扑进行射频调优的效果较好。
可选地，该方法还可以包括：对于第一AP和第二AP中的任一AP，基于该任一AP与位于该任一AP的理想覆盖范围内的终端之间的路径损耗，调节该任一AP的发射功率，使得位于该任一AP的理想覆盖范围内的终端检测到的该任一AP发送的信号的强度大于强度阈值。
基于上述功率调节方式，可以确保位于任一AP的理想覆盖范围内的终端均与该任一AP关联，进而可以在保证AP的信号覆盖质量的前提下避免AP的功率过大而造成的干扰。
可选地，该方法还可以包括：为第一AP分配第一频率的信道，并为第二AP分配第二频率的信道；其中，若第一AP与位于第二AP的理想覆盖范围内的终端之间的路径损耗大于第四损耗阈值，且第二AP与位于第一AP的理想覆盖范围内的终端之间的路径损耗大于该第四损耗阈值，则第一频率与第二频率的频率差小于第一频率阈值，即为两个AP分配的信道的频率可以相等或相近；若第一AP与位于第二AP的理想覆盖范围内的终端之间的路径损耗小于第五损耗阈值，或者，第二AP与位于第一AP的理想覆盖范围内的终端之间的路径损耗小于该第五损耗阈值，则第一频率与第二频率的频率差大于第二频率阈值，即为两个AP分配的信道的频率差别较大；其中，第四损耗阈值大于或等于第五损耗阈值，第一频率阈值小于或等于第二频率阈值。
控制器可以在确定两个AP的下行信号之间的干扰较小时，为两个AP分配频率相同或相近 的信道，并可以在确定两个AP的下行信号之间的干扰较大时，为两个AP分配不同频率的信道，以避免同频干扰。由于系统中可分配的信道数量有限，因此基于上述信道分配方式，可以确保整个系统的同频干扰较小。
可选地，该方法还可以包括：接收第一AP发送的第一接收信号强度和第二接收信号强度，该第一接收信号强度和第二接收信号强度均由目标终端发送至该第一AP；其中，第一接收信号强度为目标终端检测到的该第一AP发送的第一测量帧的强度，该第一测量帧携带第一AP的基本服务集标识(basic service set identifier，BSSID)，该第一接收信号强度用于确定第一路径损耗；第二接收信号强度为目标终端检测到的第二AP发送的第二测量帧的强度，该第二测量帧携带第一AP的BSSID，该第二接收信号强度用于确定第二路径损耗。
本申请提供的方案中，第二AP可以伪装成第一AP向该第一AP关联的目标终端发送测量帧，由此可以确保第一AP能够获取到第二AP与目标终端之间的下行链路的接收信号强度。
可选地，该方法还可以包括：在接收第一AP发送的第一接收信号强度和第二接收信号强度之前，向第一AP发送检测指令，该检测指令用于指示第一AP触发该目标终端进行接收信号强度的检测；基于第一AP在第一时段内发送的检测结果，确定该目标终端的检测成功率，其中，该检测结果用于指示该第一AP是否接收到该目标终端反馈的接收信号强度；若该检测成功率大于或等于成功率阈值，则确定目标终端在当前时刻之后的第二时段内具备接收信号强度的检测能力；基于该目标终端具备接收信号强度的检测能力，向第一AP发送针对该目标终端的强度测量指令，该强度测量指令用于指示第一AP获取第一接收信号强度和第二接收信号强度；其中，该检测成功率为在第一时段内接收到的目标检测结果个数，与在该第一时段内接收到的检测结果的总数的比值，该目标检测结果用于指示第一AP接收到目标终端反馈的接收信号强度。
本申请提供的方案中，控制器可以在确定目标终端具备接收信号强度的检测能力后，再启动对目标终端的测量，由此可以避免无效测量而导致的网络资源的浪费。
可选地，该方法还可以包括：采用箱线图算法对在第三时段内确定出的多个终端的检测成功率进行处理，得到该成功率阈值。
由于箱线图算法能够真实且直观地表现出观察值的分布情况，因此可以确保基于该箱线图算法所确定出的成功率阈值的可靠性较高。
可选地，第一AP具有包括第二AP在内的多个邻居AP，该多个邻居AP按照与第一AP之间的路径损耗由小到大的顺序排序后，该第二AP的排列序号可以小于或等于N，N为小于或等于该多个邻居AP的总数的正整数。
由于与第一AP之间的路径损耗较大的邻居AP对该第一AP的影响较小，因此在识别网络拓扑时，控制器可以仅考虑与第一AP之间的路径损耗较小的邻居AP。由此，可以在确保识别出的网络拓扑的可靠性的前提下，有效降低网络拓扑识别过程的计算量，提高网络拓扑的识别效率。
另一方面，提供了一种控制器，该控制器具有实现上述方面提供的网络拓扑的识别方法的功能，该控制器包括至少一个模块，该至少一个模块可以用于实现上述方面所提供的网络拓扑的识别方法。
又一方面，提供了一种控制器，该控制器包括：存储器，处理器及存储在该存储器上并可在该处理器上运行的计算机程序，该处理器执行该计算机程序时实现如上述方面所提供的网络拓扑的识别方法。
再一方面，提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令，该指令由处理器执行以实现如上述方面所提供的网络拓扑的识别方法。
再一方面，提供了一种包含指令的计算机程序产品，当该计算机程序产品在计算机上运行时，使得计算机执行上述方面所提供的网络拓扑的识别方法。
再一方面，提供了一种无线通信系统，该系统包括：多个AP，以及与该多个AP连接的如上述任一方面提供的控制器。
上述方面所提供的控制器、计算机可读存储介质、计算机程序产品以及无线通信系统所获得的技术效果，均与上述方面所提供的网络拓扑的识别方法中对应的技术手段获得的技术效果近似，在这里不再赘述。
综上所述，本申请提供了一种网络拓扑的识别方法、装置及无线通信系统。本申请提供的方案中，控制器所确定的第一AP、第二AP和目标终端之间的网络拓扑不仅包括两个AP之间的路径损耗，还包括AP与终端之间的路径损耗。由于AP与终端之间的路径损耗不仅可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度，因此该网络拓扑的可靠性较高。进而，可以确保基于该网络拓扑对AP进行管控(例如射频调优)的效果较好。
附图说明
图1是本申请实施例提供的一种无线通信系统的结构示意图；
图2是本申请实施例提供的另一种无线通信系统的结构示意图；
图3是5GHz频段的信道划分示意图；
图4是本申请实施例提供的又一种无线通信系统的结构示意图；
图5是本申请实施例提供的一种AP的部署场景的示意图；
图6是本申请实施例提供的另一种AP的部署场景的示意图；
图7是本申请实施例提供的一种网络拓扑的示意图；
图8是本申请实施例提供的一种网络拓扑的识别方法的流程图；
图9是本申请实施例提供的一种第一AP获取第一接收信号强度的示意图；
图10是本申请实施例提供的一种第一AP获取第二接收信号强度的示意图；
图11是本申请实施例提供的一种第一测量信息的示意图；
图12是本申请实施例提供的一种第二测量信息的示意图；
图13是本申请实施例提供的一种AP的实际覆盖范围和理想覆盖范围的示意图；
图14是本申请实施例提供的一种控制器生成终端画像的方法流程图；
图15是本申请实施例提供的一种控制器的结构示意图；
图16是本申请实施例提供的另一种控制器的结构示意图；
图17是本申请实施例提供的又一种控制器的结构示意图；
图18是本申请实施例提供的再一种控制器的结构示意图。
具体实施方式
下面结合附图详细介绍本申请实施例提供的方案。
图1是本申请实施例提供的一种无线通信系统的结构示意图，该系统可以为采用本地部署控制器的FIT AP架构的WLAN，还可以为云托管控制器管理架构的WLAN。参考图1，该系统 可以包括：控制器01，以及多个AP 02，该多个AP 02均可以与控制器01连接。并且，该系统还可以包括至少一个终端03，终端03可以与一个AP 02关联，以获取其所关联的AP 02提供的无线接入服务。例如，终端03可以先向能够探测到的AP 02发送关联请求，若某个AP 02响应了该关联请求，则终端03可以与该AP 02建立关联。
在本申请实施例中，控制器01可以为无线控制器，例如可以为AC。或者，该控制器01也可以为独立于AC且能够与AP 02通信的服务器。AP 02可以为支持WLAN的路由器或交换机等网络设备。终端03也可以称为STA，其可以为手机、电脑、可穿戴设备或智能家居设备等支持WLAN的设备。
可以理解的是，在WLAN中，单个AP 02提供的无线接入服务可以称为基本服务集(basic service set，BSS)，该BSS可以由BSSID来标识，该BSSID可以为AP 02的介质访问控制(media access control，MAC)地址。与同一个AC连接的多个AP 02所共同提供的无线接入服务可以称为扩展服务集(extended service set，ESS)，该ESS可以由同一个服务集标识(service set identifier，SSID)来标识。
图2是本申请实施例提供的另一种无线通信系统的结构示意图，如图2所示，该系统除了包括控制器01、AP 02和终端03之外，还可以包括：位于汇聚层的汇聚交换机04、位于核心层的核心交换机05、防火墙06以及路由器07。其中，AP 02位于接入层，其能够通过依次级联的汇聚交换机04、核心交换机05、防火墙06以及路由器07接入互联网或广域网(wide area network，WAN)。参考图2可以看出，该系统还可以包括位于接入层的接入交换机08，该接入交换机08可以分别与汇聚交换机04和终端03连接，用于将该终端03接入网络。
如图2所示，该控制器01可以位于汇聚层，且通过核心交换机05与多个AP 02连接。当然，该控制器01也可以位于核心层或者其他位置，本申请实施例对此不做限定。
在采用FIT AP架构的WLAN中，AC可以基于AP 02之间的网络拓扑对其所连接的多个AP 02进行管控。例如，AC可以对该多个AP 02进行射频调优，其中射频调优包括调节AP 02的发射功率和信道中的至少一种参数。
其中，调节AP 02的发射功率可以实现对AP 02发送的信号的强度的调节。并且，AP 02的发射功率越高，AP 02发送的信号的强度越强，AP 02的覆盖区域也就越大，对邻居AP的干扰也就越大。因此，AC调节AP 02的发射功率的原则可以包括：AP 02与邻居AP之间的距离越近，则将该AP 02的发射功率调节的越小。其中，AP 02的邻居AP可以是指AP 02能够探测到信号的AP，或者探测到的信号的强度大于某一阈值的AP。
调节AP 02的信道可以包括调节信道的频率和调节信道的频宽中的至少一种。示例的，图3是5吉赫兹(GHz)频段的信道划分示意图。如图3所示，该5GHz频段的频率范围为5.15GHz至5.825GHz，且该5GHz频段可划分为24个频宽为20MHz且互不重叠的信道。例如，5.15GHz至5.35GHz的频段内包括8个频宽为20MHz的信道，该8个信道的信道编号依次为36，40，44，48，52，56，60，64。参考图3可以看出，WLAN还支持将相邻的若干个信道绑定为一个频宽更宽的信道，以提供更高的信号传输速率。例如可以将相邻的2个信道绑定为频宽为40MHz的信道。
AC调节AP 02信道的原则可以包括：避免为相邻的AP 02分配同频的信道，即两个AP 02之间的距离越近，分配同频的信道的概率越小；两个AP 02之间的距离越远，分配同频的信道的概率越大。其中，同频的信道可以是指频率和频宽均相同的信道。信道的频率可以是指信道的中心频率。
由于通常情况下，相邻AP 02之间的距离越远，则相邻AP 02之间的路径损耗越大；相邻AP 02之间的距离越近，则相邻AP 02之间的路径损耗越小，因此AC一般基于相邻AP 02之间的路径损耗确定系统的网络拓扑。其中，路径损耗是指信号在路径中传播产生的损耗，该路径损耗可以等于信号发射端的发射功率与信号接收端接收到的信号的强度的差值。
但是，参考图4可以看出，WLAN是一个由AP和终端共同组成的三维空间，而AP之间的路径损耗仅能反映AP部署平面的二维拓扑，该二维拓扑缺少对三维复杂空间环境的考虑。例如图4中，假设终端STA1和STA2均与AP1关联，AP2和AP3为AP1的邻居AP，则该AP2和AP3的下行信号均会对AP1向STA1和STA2发送的下行信号造成干扰，从而影响STA1和STA2的业务体验。也即是，AP部署平面与终端分布平面之间的信号传输情况也是影响终端业务体验的重要因素。然而，基于AP之间的路径损耗所确定的二维拓扑则无法考虑到AP与终端之间的信号传输情况，导致该二维拓扑的可靠性较低。
并且，在实际部署场景中，遮挡或高挂等空间环境带来的信号折射、反射或衰减等情况都会影响AP与终端之间的信号传输质量，因此基于AP部署平面的二维拓扑进行射频调优，会导致在一些复杂部署环境中的调优结果不理想。
在一些可能的场景中，参考图5中的(a)，在体育馆或楼梯井等屋顶高度较高的空间内，可能存在多个AP 02(例如图5中的AP1和AP2)均设置在屋顶上，且相邻AP 02之间的距离较近的场景。或者，参考图5中的(b)，在屋顶下方还设置有天花板(或吊顶)的空间内，可能存在多个AP 02均设置在屋顶与天花板(或吊顶)之间，且相邻AP 02之间的距离较近的场景。在上述两种场景中，由于AC检测到的相邻AP 02之间的路损较小，因此会将该多个AP 02的发射功率均调节的较低。但是，由于AP 02与终端(例如图5中的STA1)之间的距离较远，或者，由于AP 02与终端之间存在天花板或吊顶等障碍物，因此终端检测到的AP发送的信号的强度较弱。进而，会导致AP 02与终端之间的协商速率降低，即AP 02与终端之间的数据传输速率下降，严重时可能导致终端掉线。
图5中的(a)和(b)所示的场景为高挂AP的部署场景的示例。在本申请实施例中，可以将由于设置位置较高而导致与终端之间的距离较远的AP，或者与终端之间存在诸如天花板或吊顶等障碍物的AP统称为高挂AP。
在另一些可能的场景中，参考图6中的(a)，可能存在相邻AP 02(例如图6中的AP1和AP2)之间距离较近，但两者之间存在横梁的场景。或者，参考图6中的(b)，可能存在相邻AP 02之间距离较近，但两者之间存在具有拐角的墙体的场景。又或者，参考图6中的(c)，在具有中庭的空间内，还可能存在多个AP 02部署在不同楼层的屋顶上的场景。在上述场景中，由于相邻AP 02之间存在遮挡物，因此AC检测到的相邻AP 02之间的路损较大，进而会为该多个AP 02分配相同频率的信道。但是，在上述场景中，若各个AP 02与终端(例如图6中的STA1)之间均不存在遮挡，则可能导致终端侧的同频干扰较为严重，进而导致终端的应用层速率下降，终端的业务体验较差。图6中的(a)至(c)所示的场景为AP之间存在遮挡物的部署场景的示例。
基于上述分析可知，对于AP 02设置位置较高，AP 02与终端之间存在遮挡物，或者AP 02之间存在遮挡物的场景，仅基于AP 02之间的路损将无法准确地确定系统的网络拓扑。相应的，基于该网络拓扑对AP 02进行管控时的可靠性较低。
本申请实施例提供了一种网络拓扑的识别方法，可以解决基于AP 02之间的路损确定出的 网络拓扑的可靠性较低的技术问题。本申请实施例提供的方法可以应用于控制器中，例如可以应用于图1或图2所示系统中的控制器01。
在本申请实施例提供的方法中，控制器能够确定第一AP、第二AP和目标终端之间的网络拓扑，其中，该目标终端与第一AP关联，该第二AP为第一AP的邻居AP。该网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗，该第一路径损耗是第一AP与目标终端之间的路径损耗，该第二路径损耗是第二AP与目标终端之间的路径损耗，该第三路径损耗是第一AP与第二AP之间的路径损耗。
可以理解的是，该目标终端可以是与第一AP关联的任一终端。并且，该目标终端可以是WLAN中的用户终端，或者，也可以是WLAN中设置的专用于识别网络拓扑的测试终端，本申请实施例对此不做限定。
在本申请实施例中，AP与目标终端之间的路径损耗可以是指AP与目标终端之间的下行链路的路径损耗；或者，可以是指AP与目标终端之间的上行链路的路径损耗；又或者，AP与目标终端之间的路径损耗可以包括下行链路的路径损耗和上行链路的路径损耗。
第一AP的邻居AP可以是指第一AP能够探测到信号的AP，或者探测到的信号的强度大于某一阈值的AP。并且，第一AP及其邻居AP可以由同一个AC管控，也可以由不同的AC管控，本申请实施例对此不做限定。
可以理解的是，控制器所确定出的第一AP、第二AP和目标终端之间的网络拓扑可以是指路径损耗的集合。如图7所示，该路径损耗的集合包括不仅包括第一AP和第二AP之间的路径损耗，还包括AP与终端之间的路径损耗，即本申请实施例提供的方案所确定出的网络拓扑为三维(3-dimension，3D)立体的网络拓扑。该网络拓扑能够全面真实的反映信号在空间中传播的情况，以及信号对终端和AP的影响。例如，AP与终端之间的路径损耗可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度。该3D网络拓扑的可靠性较高，以该3D网络拓扑为基础进行射频调优能够更好地适应复杂多变的空间环境，提升射频调优算法的环境泛化性。
图8是本申请实施例提供的一种网络拓扑的识别方法的流程图，该方法可以应用于如图1或图2所示的无线通信系统中。由于AP与终端之间的下行链路的路径损耗是影响终端业务体验的重要因素，因此下文以AP与终端之间的路径损耗为下行链路的路径损耗为例进行说明。参考图8，该方法可以包括：
步骤101、控制器向第一AP发送针对目标终端的强度测量指令。
该目标终端与第一AP关联，该强度测量指令可以用于指示第一AP获取第一接收信号强度，该第一接收信号强度是指目标终端检测到的第一AP发送的测量帧的强度，即第一AP与目标终端之间的下行链路的接收信号强度。
可选地，该针对目标终端的强度测量指令可以携带目标终端的标识，例如，可以携带有目标终端的MAC地址。
步骤102、第一AP向目标终端发送第一测量帧。
第一AP接收到控制器发送的针对目标终端的强度测量指令后，可以基于该强度测量指令向目标终端发送第一测量帧。该第一测量帧可以携带第一AP的BSSID，该BSSID可以为第一AP的MAC地址。其中，第一测量帧是一种WLAN帧，例如，该第一测量帧可以为链路测量请求(link measurement request)帧，该链路测量请求帧可以用于请求接收信号强度指标(received  signal strength indicator，RSSI)。
示例的，参考图9，假设第一AP为AP1，目标终端为STA1，则AP1可以向STA1发送第一测量帧。
步骤103、第一AP向第二AP发送测量请求。
在一种可能的实现方式中，第一AP接收到的强度测量指令还可以用于指示第一AP获取第二接收信号强度。该第二接收信号强度是指目标终端检测到的第二AP发送的测量帧的强度，即第二AP与目标终端之间的下行链路的接收信号强度，该第二AP为第一AP的邻居AP。例如，该强度测量指令中可以包括第二AP的标识(例如第二AP的MAC地址)，第一AP可以基于该强度测量指令向第二AP发送测量请求。测量请求可以包括第一AP的BSSID，以及第一AP与目标终端关联时所采用的信道。该测量请求用于指示第二AP伪装成第一AP向目标终端发送第二测量帧。
示例的，参考图10，假设第二AP为AP2，则AP1接收到强度测量指令后可以向AP2发送测量请求。
在另一种可能的实现方式中，控制器可以直接向第二AP发送针对目标终端的强度测量指令，该强度测量指令中可以包括第一AP的BSSID，以及第一AP与目标终端关联时所采用的信道。发送至第二AP的强度测量指令可以用于指示该第二AP伪装成第一AP向目标终端发送第二测量帧。
在又一种可能的实现方式中，第二AP中预先存储有第一AP的BSSID，以及第一AP与目标终端关联时所采用的信道。第二AP在接收到第一AP发送的测量请求或控制器发送的强度测量指令后，可以基于预先存储的信息伪装成第一AP向目标终端发送第二测量帧。
步骤104、第二AP向目标终端发送第二测量帧。
在本申请实施例中，第二AP接收到第一AP发送的测量请求或控制器发送的强度测量指令后，可以向目标终端发送第二测量帧。其中，该第二测量帧携带有第一AP的BSSID，且第二AP发送该第二测量帧所采用的信道即为第一AP与目标终端关联时所采用的信道(下文称为目标信道)。由此，第二AP即可伪装成第一AP向目标终端发送第二测量帧，以确保该第二测量帧能够被目标终端接收到。示例的，参考图10，AP2可以基于AP1发送的测量请求，向STA1发送第二测量帧。
可以理解的是，若第二AP当前的工作信道与目标信道相同，则第二AP无需切换信道。若第二AP当前的工作信道与目标信道不同，则第二AP可以临时切换至该目标信道以发送第二测量帧。并且，第二AP在通过该目标信道发送完第二测量帧后，可以立即切换回原来的工作信道，以避免影响第二AP的其他业务。
步骤105、目标终端向第一AP发送第一测量响应帧。
目标终端接收到第一AP发送的第一测量帧后，可以从第一测量帧中获取第一AP的BSSID，并基于该BSSID向第一AP反馈第一测量响应帧。该第一测量响应帧中包括目标终端检测到的第一测量帧的强度，即第一接收信号强度。例如，参考图9，STA1可以向AP1发送第一测量响应帧。
步骤106、目标终端向第一AP发送第二测量响应帧。
目标终端接收到第二AP发送的第二测量帧后，由于该第二测量帧中携带的BSSID为第一AP的BSSID，因此目标终端可以基于该第一AP的BSSID向第一AP反馈第二测量响应帧。该第二测量响应帧中包括目标终端检测到的第二测量帧的强度，即第二接收信号强度。例如，参 考图10，STA2接收到AP2发送的第二测量帧后，可以向AP1发送第二测量响应帧。其中，目标终端向第一AP反馈的测量响应帧可以为链路测量报告(link measurement request)帧。
可选地，该第一接收信号强度和第二接收信号强度均可以采用RSSI来表示。
在本申请实施例中，若第一AP具有包括第二AP在内的多个邻居AP，则作为一种可能的示例，控制器可以获取每个邻居AP与目标终端之间的下行链路的接收信号强度。也即是，第一AP的每个邻居AP均可以在控制器发送的强度测量指令或第一AP发送的测量请求的指示下，伪装成第一AP向目标终端发送测量帧。相应的，目标终端可以向第一AP反馈针对每个邻居AP发送的测量帧的测量响应帧。
作为另一种可能的示例，由于与第一AP之间的路损过大的邻居AP对该第一AP的影响较小，因此在识别网络拓扑时，控制器可以仅考虑与第一AP之间的路径损耗较小的邻居AP。由此，可以在确保识别出的网络拓扑的可靠性的前提下，有效降低网络拓扑识别过程的计算量，提高网络拓扑的识别效率。
例如，控制器可以将第一AP的多个邻居按照与第一AP之间的路径损耗由小到大的顺序进行排序，并将排列序号小于或等于N的邻居AP确定为需扫描的邻居AP。之后，控制器可以获取每个需扫描的邻居AP与目标终端之间的下行链路的接收信号强度。也即是，第一AP的多个邻居AP中，仅需扫描的邻居AP可以在控制器发送的强度测量指令或第一AP发送的测量请求的指示下，伪装成第一AP向目标终端发送测量帧。相应的，目标终端可以向第一AP反馈针对每个需扫描的邻居AP发送的测量帧的测量响应帧。可以理解的是，第二AP属于需扫描的邻居AP，即第二AP的排列序号小于或等于N。
上述示例中，N为小于或等于该多个邻居AP的总数的正整数。其中，当第一AP的邻居AP的总数大于数量阈值时，即邻居AP的个数较多时，N可以小于该多个邻居AP的总数。当第一AP的邻居AP的总数不大于该数量阈值时，即邻居AP的个数较少时，N可以等于该多个邻居AP的总数。
示例的，假设N＝10，则控制器可以将与第一AP之间的路径损耗最小的前10个邻居AP确定为需扫描的邻居AP，并可以在发送至第一AP的强度测量指令中携带该10个邻居AP的MAC地址。第一AP进而可以基于该强度测量指令，分别向该10个邻居AP发送测量请求。
步骤107、第一AP向控制器发送第一接收信号强度和第二接收信号强度。
第一AP接收到目标终端反馈的第一测量响应帧后，可以从该第一测量响应帧中获取第一接收信号强度，并向控制器发送该第一接收信号强度。第一AP接收到目标终端反馈的第二测量响应帧后，可以从该第二测量响应帧中获取第二接收信号强度，并向控制器发送该第二接收信号强度。
可以理解的是，由于第一AP可以与包括目标终端在内的多个终端关联，因此对于第一AP关联的每个终端，均可以通过上述步骤101至107所示的方法获取第一AP与该终端之间的下行链路的接收信号强度，以及第二AP与该终端之间的下行链路的接收信号强度。
可选地，在本申请实施例中，第一AP可以分别向控制器发送第一测量信息和第二测量信息。该第一测量信息为第一AP对其关联的终端(例如目标终端)进行测量得到的测量信息，该第二测量信息是指通过第二AP伪装成第一AP发送测量帧的方式所测量得到的信息。其中，该第一测量信息除了包括上述第一接收信号强度之外，还可以包括终端的标识(例如MAC地址)，以及第一AP的BSSID等信息。该第二测量信息除了包括上述第二接收信号强度之外，还可以包括终端的标识，第一AP的BSSID以及第二AP的BSSID等信息。
示例的，图11是本申请实施例提供的一种第一测量信息的示意图。参考图11可以看出，第一AP向控制器上报的第一测量信息可以包括如下字段：sta_mac，dl_rssi，dl_linkmargin，sta_tx_power，ul_rssi，tx_rate，rx_rate，radio_id，bssid，ssid，assoc_timestamp，online_time。
其中，sta_mac字段的字段类型为字节(byte)型，长度为6字节，字段标识(identifier，ID)为1，该sta_mac字段用于携带终端(例如目标终端)的MAC地址。
dl_rssi字段的字段类型为字符(char)型，长度为1字节，字段ID为2，该dl_rssi字段用于携带终端检测到的第一AP与该终端之间的下行链路(downlink，DL)的接收信号强度，例如上述第一接收信号强度。该下行链路的接收信号强度可以采用RSSI表示。
dl_linkmargin字段的字段类型为char型，长度为1字节，字段ID为3，该dl_linkmargin字段用于携带第一AP基于传输功率控制请求(TPC request；transmit power control，TPC)帧测量得到的该第一AP与终端之间的下行链路的链路余量(link margin，LM)。
sta_tx_power字段的字段类型为8位无符号整型(unit8)，长度为1字节，字段ID为4，该sta_tx_power字段用于携带终端发送测量响应帧时所使用的功率(power)。例如，对于目标终端，该sta_tx_power字段可以携带该目标终端发送第一测量响应帧所使用的功率。可以理解的是，该sta_tx_power字段携带的功率由终端上报至第一AP。
ul_rssi字段的字段类型为char型，长度为1字节，字段ID为5，该ul_rssi字段用于携带第一AP检测到的该第一AP与终端之间的上行链路(uplink，UP)的接收信号强度，即第一AP检测到的终端发送的信号的强度。该上行链路的接收信号强度也可以采用RSSI表示。
tx_rate字段的字段类型为32位无符号整型(unit32)，长度为4字节，字段ID为6，该tx_rate字段用于携带第一AP的发送(transmit，TX)链路的速率(rate)，速率的单位为兆比特每秒(megabits per second，Mbps)。
rx_rate字段的字段类型为unit32，长度为4字节，字段ID为7，该tx_rate字段用于携带第一AP的接收(receive，RX)链路的速率，速率的单位为Mbps。其中，第一AP的TX链路即为第一AP与终端之间的下行链路，RX链路即为第一AP与终端之间的上行链路。
radio_id字段的字段类型为unit8，长度为1字节，字段ID为8，该tx_rate字段用于携带第一AP当前所工作的射频(radio)频段的ID。该第一AP工作的射频频段可以为2.4GHz频段或5GHz频段。
bssid字段的字段类型为byte型，长度为6字节，字段ID为9，该bssid字段用于携带第一AP的BSSID。
ssid字段的字段类型为字符串(string)类型，长度为32+1字节，字段ID为10，该ssid字段用于携带第一AP的SSID。其中，32+1字节是指前32个字节用于携带SSID，最后一个字节用于携带结束符。
assoc_timestamp字段的字段类型为unit32，长度为4字节，字段ID为11，该assoc_timestamp字段用于携带终端接入其所关联的(associate，assoc)的AP，即第一AP的时间戳(timestamp)。
online_time字段的字段类型为unit32，长度为4字节，字段ID为12，该online_time字段用于携带终端的在线(online)时长，即终端已接入第一AP的时长。
图12是本申请实施例提供的一种第一AP向控制器发送的第二测量信息的示意图。参考图12可以看出，该第二测量信息可以包括sta_mac，radio_id，assoc_bssid，assoc_ssid，assoc_dl_val，expected_neighbor_num，neighbor_num，neighbor_bssid_1，以及neighbor_dl_val_1等字段。
其中，sta_mac字段的字段类型为byte型，长度为6字节，字段ID为1，该sta_mac字段用于 携带终端的MAC地址。
radio_id字段的字段类型为unit8，长度为1字节，字段ID为2，该radio_id字段用于携带第一AP当前工作的射频频段的ID。
assoc_bssid字段的字段类型为byte型，长度为6字节，字段ID为3，该assoc_bssid字段用于携带第一AP的BSSID。可以理解是，由于第一AP是与目标终端关联的AP，因此也可以称为关联AP。
assoc_ssid字段的字段类型为string，长度为32+1字节，字段ID为4，该assoc_bssid字段用于携带第一AP的SSID。
assoc_dl_val字段的字段类型为char型，长度为1字节，字段ID为5，该assoc_dl_val字段用于携带第一AP与终端之间的下行链路的接收信号强度。
expected_neighbor_num字段的字段类型为unit8，长度为1字节，字段ID为10，该expected_neighbor_num字段用于携带期望(expected)扫描的邻居(neighbor)AP的数量。
该期望扫描的邻居AP的数量可以是指第一AP基于强度测量指令发送了测量请求的邻居AP的数量。例如，若控制器指示获取每个邻居AP与目标终端之间的下行链路的接收信号强度，则第一AP可以向每个邻居AP均发送测量请求，相应的，该期望扫描的邻居AP的数量即为第一AP包括的邻居AP的总数。若控制器指示仅获取N个需扫描的邻居AP与目标终端之间的下行链路的接收信号强度，则第一AP可以仅向N个需扫描的邻居AP发送测量请求，相应的，该期望扫描的邻居AP的数量即为N。
neighbor_num字段的字段类型为unit8，长度为1字节，字段ID为6，该neighbor_num字段用于携带一个测量周期(例如1秒)内有效的邻居AP的数量。
该有效的邻居AP是指在接收到第一AP发送的测量请求后，向终端发送测量帧的邻居AP。可以理解的是，第一AP向邻居AP发送测量请求后，部分邻居AP可能会由于无法切换信道等因素的影响而不响应该测量请求，即邻居AP不向终端发送测量帧，进而导致第一AP无法获取到该邻居AP与终端之间的下行链路的接收信号强度。因此，在本申请实施例中，第一AP还可以向控制器上报有效的邻居AP的数量。
neighbor_bssid字段的字段类型为byte型，长度为6字节，字段ID为7，该neighbor_bssid字段用于携带第一AP的邻居AP(例如第二AP)的BSSID。
neighbor_dl_val字段的字段类型为char型，长度为1字节，字段ID为8，该neighbor_dl_val字段用于携带邻居AP与终端之间的下行链路的接收信号强度，例如可以携带上述第二接收信号强度。
可以理解的是，对于第一AP具有多个邻居AP的场景，第一AP可以获取到终端对多个邻居AP的接收信号强度。因此，作为一种可能的示例，若第一AP在一个测量周期内接收到了终端反馈的多个邻居AP的接收信号强度，则该第二测量信息可以包括多个neighbor_bssid字段和多个neighbor_dl_val字段，其中每个neighbor_bssid字段可以携带一个邻居AP的BSSID，每个neighbor_dl_val字段可以携带一个邻居AP与终端之间的下行链路的接收信号强度。作为另一种可能的示例，若第一AP在一个测量周期内仅接收到了终端反馈的一个邻居AP的接收信号强度，则该第二测量信息可以携带一个邻居AP的BSSID，以及一个邻居AP与目标终端之间的下行链路的接收信号强度，且第一AP可以分次向控制器上报多个第二测量信息。
可选地，在本申请实施例中，第一AP在接收到针对目标终端的强度测量指令后，可以每隔第一测量周期(例如1秒)向目标终端发送一次测量帧。由于目标终端接收到该测量帧后能 够在远小于第一时长的时长内(例如几毫秒内)反馈第一测量响应帧，因此该第一AP可以每隔第一测量周期向控制器发送一次第一测量信息。
由于邻居AP(例如第二AP)在接收到测量请求或强度测量指令后，可能需要切换工作信道来发送第二测量帧，即第二AP发送测量帧所需的时长较长，因此第一AP接收到第二接收信号强度所需的时长也较长。相应的，第一AP可以每隔第二测量周期向控制器发送一次第二测量信息。其中，该第二测量周期的时长可以大于或等于第一测量周期的时长。例如，该第二测量周期的时长可以为1至10秒。
步骤108、第一AP向控制器发送第三接收信号强度。
该第三接收信号强度是指第一AP检测到的第二AP发送的测量帧的强度，且该第三接收信号强度也可以采用RSSI表示。在本申请实施例中，控制器还可以按照预设的检测周期，周期性地向其所管控的各个AP发送强度检测指令。接收到强度检测指令的AP可以向邻居AP发送测量帧，邻居AP进而可以检测其所接收到的测量帧的强度，并将检测到的强度上报至控制器。其中，该检测周期的时长可以为1天。
示例的，控制器可以在每天凌晨分别向第一AP和第二AP发送强度检测指令，第二AP可以基于该强度检测指令向第一AP发送测量帧，第一AP可以检测接收到的测量帧的强度，即第三接收信号强度，并将该第三接收信号强度上报至控制器。
步骤109、控制器基于该第一接收信号强度、第二接收信号强度和第三接收信号强度确定第一AP、第二AP和目标终端之间的网络拓扑。
该网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗。该第一路径损耗是第一AP与目标终端之间的路径损耗，该第二路径损耗是第二AP与目标终端之间的路径损耗，该第三路径损耗是第一AP与第二AP之间的路径损耗。
其中，控制器可以基于该第一接收信号强度确定第一路径损耗，基于该第二接收信号强度确定第二路径损耗，并基于该第三接收信号强度确定第三路径损耗。例如，该第一路径损耗等于第一AP的发射功率与该第一接收信号强度的差值，该第二路径损耗等于第二AP的发射功率与该第二接收信号强度的差值，该第三路径损耗等于第一AP的发射功率与该第三接收信号强度的差值。
可以理解的是，若控制器为AC，则由于第一AP和第二AP的发射功率均由AC控制，因此AC中存储有各个AP的发射功率。若控制器为独立于AC的服务器，则服务器可以获取AC发送的各个AP的发射功率，或者可以获取各个AP上报的发射功率。
对于该第一AP具有包括第二AP在内的多个邻居AP的场景，作为一种可能的实例，控制器能够获取到每个邻居AP与目标终端之间的下行链路的接收信号强度。相应的，控制器可以确定出该第一AP、多个邻居AP和目标终端之间的网络拓扑。也即是，该网络拓扑包括第一路径损耗，每个邻居AP与目标终端之间的路径损耗，以及第一AP与每个邻居AP之间的路径损耗。
作为另一种可能的示例，控制器可以从该多个邻居AP中确定出N个需扫描的邻居AP，则控制器能够获取到每个需扫描的邻居AP与目标终端之间的下行链路的接收信号强度。相应的，控制器可以确定出该第一AP、N个需扫描的邻居AP和目标终端之间的网络拓扑。也即是，该网络拓扑包括第一路径损耗，每个需扫描的邻居AP与目标终端之间的路径损耗，以及第一AP与每个需扫描的邻居AP之间的路径损耗。
示例的，假设控制器确定出的第一AP的N个需扫描的邻居AP至少包括第二AP和第三AP，则控制器基于第一AP上报的接收信号强度确定出的各个AP与目标终端之间的路径损耗可以 如表1所示。参考表1可以看出，第一AP的标识为N1_5F_1，目标终端对该第一AP的接收信号强度(即第一接收信号强度)为-50分贝毫瓦(dBm)。假设该第一AP的发射功率为5dBm，则控制器可以确定该第一AP与目标终端之间的下行链路的第一路径损耗为55dBm。第二AP的标识为N1_5F_13，目标终端对该第二AP的接收信号强度(即第二接收信号强度)为-60dBm。假设该第二AP的发射功率为5dBm，则控制器可以确定该第二AP与目标终端之间的下行链路的第二路径损耗为65dBm。第三AP的标识为N1_5F_26，目标终端对该第三AP的接收信号强度为-65dBm。假设该第三AP的发射功率为5dBm，则控制器可以确定该第三AP与目标终端之间的下行链路的路径损耗为70dBm。
表1
AP AP的标识 接收信号强度 路径损耗
第一AP N1_5F_1 -50 55
第二AP N1_5F_13 -60 65
第三AP N1_5F_26 -65 70
... ... ... ...
还可以理解的是，第一AP能够与包括目标终端在内的多个终端关联，对于每个终端，控制器均可以获取到该终端与第一AP之间的路径损耗，以及该终端与每个邻居AP之间的路径损耗。因此，控制器可以确定出第一AP、该第一AP的多个邻居AP以及该第一AP关联的多个终端之间的网络拓扑。也即是，控制器确定出的网络拓扑可以包括：第一路径损耗，第一AP的每个邻居AP与第一AP所关联的各个终端之间的路径损耗，以及第一AP与每个邻居AP之间的路径损耗。
步骤110、控制器将第一AP和第一AP的多个邻居AP中与目标终端之间的路径损耗最小的AP确定为该目标终端归属的归属AP。
控制器获取到第一AP以及第一AP的邻居AP与目标终端之间的路径损耗后，还可以将第一AP和多个邻居AP中与目标终端之间的路径损耗最小的AP确定为该目标终端归属的归属AP，即目标终端归属的归属AP是指与该目标终端之间的路径损耗最小的AP。可以理解的是，在目标终端与各个AP之间均不存在遮挡物的前提下，该目标终端的归属AP即为与该目标终端距离最近的AP。还可以理解的是，该归属AP与目标终端关联的关联AP并不等同。相应的，对于该归属AP来说，该归属AP关联的终端与归属于该归属AP的终端也不等同。
可以理解的是，对于该归属AP，若某个终端与该归属AP之间的路径损耗小于与其他AP之间的路径损耗，则该终端即为归属于该归属AP的终端。或者可以理解为：归属于该归属AP的终端是指在理想情况下应当与该归属AP关联的终端。
示例的，参考图13，假设第一AP为AP1，与AP1关联的目标终端为STA1。若STA1与AP1之间的路径损耗最小，则控制器可以将AP1确定为该STA1归属的归属AP，即STA1的归属AP和关联AP均为AP1。
或者，假设第一AP为AP2，与AP2关联的目标终端为STA2。若STA2与AP1之间的路径损耗最小，则控制器可以将AP1确定为该STA2归属的归属AP，即STA2的归属AP和关联AP为不同的AP。
可以理解的是，对于第一AP关联的每个终端，控制器均可以基于上述步骤110所示的方法确定该终端所归属的归属AP。
步骤111、控制器基于归属于该归属AP的终端确定该归属AP的理想覆盖范围。
控制器确定出目标终端所归属的归属AP后，还可以基于归属于该归属AP的终端确定该归属AP的理想覆盖范围，即可以将归属于该归属AP的终端所在的区域确定为该归属AP的理想覆盖范围。其中，AP的理想覆盖范围可以是指既能够确保位于该范围内的终端的通信质量需求，又可以避免AP之间的下行信号的干扰的覆盖范围。可以理解的是，控制器基于终端与AP之间的路径损耗所确定出的理想覆盖范围是稳定的范围，该理想覆盖范围不会随着AP发射功率的变化而改变。
在本申请实施例中，可以将某个AP所关联的各个终端所在的区域称为该AP的实际覆盖范围，该实际覆盖范围并非是固定的，而是与AP的发射功率相关。例如，若AP的发射功率较高，则与该AP距离较远的终端也能够与该AP关联，该AP的实际覆盖范围也就越大。反之，若AP的发射功率较低，则仅与该AP距离较近的终端能够与该AP关联，该AP的实际覆盖范围也就越小。示例的，参考图13中的虚线框可以看出，若AP2的发射功率大于AP1的发射功率，则不仅归属于AP2的STA3和STA4会与AP2关联，归属于AP1的STA2也会与AP2关联。
可以理解的是，若终端与距离较远的AP关联，则由于终端与AP之间的路径损耗较大，因此AP需提供较大的发射功率才能保证终端的接收信号强度满足通信质量的需求。由此，不仅导致AP的功耗较高，而且会对其他AP造成较大的干扰。
在本申请实施例中，控制器确定出的AP的理想覆盖范围可以用于进行射频调优。例如，控制器可以基于该理想覆盖范围调节AP的发射功率，从而使得AP能够与位于其理想覆盖范围内的终端关联，而不会与位于其理想覆盖范围之外的终端关联，也即是，可以将AP的实际覆盖范围调整为与AP的理想覆盖范围相同的范围。由此，可以确保AP能够基于就近服务的原则为终端提供网络接入的服务，即终端能够与路径损耗最小的AP关联。进而，可以确保AP不需要很高的发射功率即可使得终端的接收信号强度满足通信质量的需求，也即是，可以在保证AP的信号覆盖质量的前提下避免AP的功率过大而造成的干扰。
基于上述步骤107可知，第一AP可以上报其所关联的终端检测到接收信号强度。相应的，控制器在存储路径损耗时，能够以AP为粒度分别统计每个AP的终端测量数据。以第一AP为例，该第一AP的终端测量数据可以包括：第一AP与其所关联的每个终端之间的路径损耗，以及邻居AP与上述每个终端之间的路径损耗。
控制器在确定出AP的理想覆盖范围之后，还可以基于该理想覆盖范围对其所记录的AP的终端测量数据进行调整。以第一AP为例，调整后的第一AP的终端测量数据可以包括：第一AP与位于第一AP的理想覆盖范围内的每个终端之间的路径损耗，以及邻居AP与上述每个终端之间的路径损耗。
例如，若某个终端所关联的关联AP并非是其归属AP，则控制器可以将各个AP与该终端之间的路径损耗从关联AP的终端测量数据中删除(该删除操作也称为去粘性)，并将各个AP与该终端之间的路径损耗添加至归属AP的终端测量数据中(该添加操作也称为补粘性)。
示例的，参考图13，假设归属于AP1的STA2与AP2关联，则控制器可以将各个AP与STA2之间的路径损耗从AP2的终端测量数据中删除，并将各个AP与STA2之间的路径损耗添加至AP1的终端测量数据中。
步骤112、控制器识别该第一AP和第二AP中的任一AP是否为高挂AP。
在本申请实施例中，对于第一AP和第二AP中的任一AP，控制器可以基于该任一AP与多个终端之间的路径损耗，确定该任一AP是否为高挂AP。高挂AP是指与多个终端之间的距离 大于距离阈值，或与多个终端之间存在遮挡物的AP。例如，参考图5的(a)，该高挂AP可以包括设置在较高的屋顶上的AP，或者，参考图5的(b)，设置在屋顶与天花板(或吊顶)之间的AP。
作为一种可能的实现方式，该多个终端可以是指任一AP的理想覆盖范围内的终端。控制器可以在检测到任一AP与位于该任一AP的理想覆盖范围内的终端之间的路径损耗均大于第一损耗阈值时，确定该任一AP为高挂AP。
作为另一种可能的实现方式，该多个终端可以是指与任一AP关联的终端。控制器可以在检测到任一AP与其所关联的每个终端之间的路径损耗均大于第一损耗阈值时，确定该任一AP为高挂AP。其中，该第一损耗阈值可以为控制器中预先配置的固定值，例如可以是根据专家经验在控制器中输入的固定值或者控制器根据网络环境的实时数据和/或历史数据计算得到损耗阈值。
基于上述两种实现方式可知，若AP与多个终端之间的路径损耗均较大，则控制器可以确定该AP的部署位置与终端的分布平面之间的距离较远，或者与终端的分布平面之间存在遮挡物，进而可以确定该任一AP为高挂AP。
控制器若识别出某个AP为高挂AP，则可以确定该AP与终端之间的路径损耗较大。相应的，在后续进行射频调优时，可以将该高挂AP的发射功率调节的较高，以确保终端(可以是指与该高挂AP关联的终端，或位于该高挂AP的理想覆盖范围内的终端)的接收信号强度能够满足通信质量的需求。
步骤113、控制器确定该第一AP和第二AP之间是否存在遮挡物。
在本申请实施例中，控制器还可以基于第一AP、第二AP和目标终端之间的网络拓扑，确定第一AP和第二AP之间是否存在遮挡物。可以理解的是，AP之间的遮挡情况也可以作为后续对AP进行射频调优时的依据，以提高射频调优的可靠性。
作为一种可能的实现方式，控制器若确定第一AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，且第一AP与第二AP之间的第三路径损耗大于第三损耗阈值，则可以确定该第一AP和第二AP之间存在遮挡物。
示例的，参考图6中的(a)至(c)，控制器若确定AP1与位于该AP1的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，AP2与位于该AP2的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，且AP1与AP2之间的第三路径损耗大于第三损耗阈值，则可以确定该AP1与AP2之间存在遮挡物。
作为另一种可能的实现方式，控制器若确定第一AP与其所关联的终端之间的路径损耗小于第二损耗阈值，该第二AP与第一AP所关联的终端之间的路径损耗小于该第二损耗阈值，且第一AP与第二AP之间的第三路径损耗大于第三损耗阈值，则可以确定该第一AP和该第二AP之间存在遮挡物。
基于上述两种实现方式可知，控制器可以在检测到两个AP中的每个AP与终端之间的路径损耗均较小，但两个AP之间的路径损耗较大时，确定该两个AP之间存在遮挡物。可以理解的是，上述第二损耗阈值和第三损耗阈值均为控制器中预先配置的固定值，例如可以是根据专家经验在控制器中输入的固定值或者控制器根据网络环境的实时数据和/或历史数据计算得到损耗阈值。并且，该第二损耗阈值和第三损耗阈值可以相等，也可以不等。
可以理解的是，控制器若确定第一AP与位于该第一AP的理想覆盖范围内的终端之间的路 径损耗小于第二损耗阈值，第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗也小于第二损耗阈值，且第一AP与第二AP之间的第三路径损耗不大于第三损耗阈值，则可以确定该第一AP和第二AP之间不存在遮挡物。
控制器若确定第一AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗不小于第二损耗阈值，且第一AP与第二AP之间的第三路径损耗大于第三损耗阈值，则也可以确定该第一AP和第二AP之间不存在遮挡物。
步骤114、控制器基于该第一AP、第二AP和目标终端之间的网络拓扑，对该第一AP和第二AP中的至少一个AP进行射频调优。
其中，射频调优可以包括调节AP的发射功率，和/或，调节AP的信道。
作为一种可能的示例，对于该第一AP和该第二AP中的任一AP，控制器可以基于该任一AP与位于该任一AP的理想覆盖范围内的终端之间的路径损耗，调节该任一AP的发射功率，使得位于该任一AP的理想覆盖范围内的终端检测到的该任一AP发送的信号的强度(即下行链路的接收信号强度)均大于强度阈值，以确保该任一AP的理想覆盖范围内的终端的接收信号强度均能满足通信质量的需求。其中，该强度阈值可以为控制器中预先配置的固定值，且该强度阈值的大小可以是根据经验确定的，或者可以是根据网络环境的实时数据和/或历史数据计算得到。例如，该强度阈值可以是根据经验确定的-65dBm。
基于上述功率调节方式，可以确保位于任一AP的理想覆盖范围内的终端均与该任一AP关联，进而可以在保证AP的信号覆盖质量的前提下避免AP的功率过大而造成的干扰。
作为另一种可能的示例，控制器可以基于网络拓扑为第一AP分配第一频率的信道，并为第二AP分配第二频率的信道。该第一频率和第二频率可以满足如下条件：
一方面，若第一AP与位于第二AP的理想覆盖范围内的终端之间的路径损耗大于第四损耗阈值，且第二AP与位于第一AP的理想覆盖范围内的终端之间的路径损耗大于该第四损耗阈值，则控制器可以确定每个AP对另一AP的理想覆盖范围内的终端的干扰较小，因此可以为该两个AP分配同频或频率相近的信道。相应的，该第一频率与该第二频率的频率差可以小于第一频率阈值，例如，该第一频率可以等于该第二频率。
另一方面，若第一AP与位于第二AP的理想覆盖范围内的终端之间的路径损耗小于第五损耗阈值，或者，第二AP与位于第一AP的理想覆盖范围内的终端之间的路径损耗小于该第五损耗阈值，则控制器可以确定AP对另一AP的理想覆盖范围内的终端的干扰较大，该两个AP的信道的频率需错开。相应的，该第一频率与该第二频率的频率差可以大于第二频率阈值。
又一方面，控制器若基于上述步骤113确定第一AP和第二AP之间不存在遮挡物，且第一AP和第二AP之间的路径损耗较大(例如大于第三损耗阈值)，则也可以确定每个AP对另一AP的理想覆盖范围内的终端的干扰较小，因此可以为该两个AP分配同频或频率相近的信道。即该场景下，第一频率与该第二频率的频率差也可以小于第一频率阈值。
可以理解的是，上述第四损耗阈值、第五损耗阈值、第一频率阈值以及第二频率阈值均为控制器中预先配置的固定值。并且，该第四损耗阈值可以大于或等于第五损耗阈值，该第一频率阈值可以小于或等于第二频率阈值。
基于上述信道分配方式可知，控制器可以在确定两个AP的下行信号之间的干扰较小时，为两个AP分配频率相同或相近的信道，并可以在确定两个AP的下行信号之间的干扰较大时，为两个AP分配不同频率的信道，以避免同频干扰。由于系统中可分配的信道数量有限，因此 基于本申请实施例提供的信道分配方式，可以确保整个系统的同频干扰较小。
图14是本申请实施例提供的一种控制器生成终端画像的方法流程图，参考图14，该方法可以包括：
步骤115、控制器检测目标终端的终端画像当前是否有效。
在本申请实施例中，控制器中可以预先存储有目标终端的终端画像，该终端画像可以用于指示目标终端当前是否具备接收信号强度的检测能力。并且，为了确保终端画像的时效性，该终端画像具有一定的有效时长。控制器可以在确定终端画像的有效时长到期时，即确定终端画像无效时，重新更新该终端画像。
在本申请实施例中，控制器若确定该目标终端的终端画像无效或者未存储该目标终端的终端画像，则可以执行步骤116，控制器若确定目标终端的终端画像有效，则可以执行步骤122。
可选地，控制器可以在检测到目标终端上线时(即目标终端与第一AP建立关联时)，检测该目标终端的终端画像当前是否有效。其中，若该目标终端为新入网的终端，即目标终端首次与该控制器所连接的AP关联，则控制器中未存储该目标终端的终端画像。
步骤116、控制器向第一AP发送检测指令。
控制器若确定该目标终端的终端画像无效或者未存储该目标终端的终端画像，则可以向第一AP发送检测指令。该检测指令可以用于指示该第一AP触发目标终端进行接收信号强度的检测。
步骤117、第一AP向目标终端发送测量帧。
第一AP接收到控制器发送的检测指令后，可以基于该检测指令向目标终端发送测量帧。若目标终端当前具备接收信号强度的检测能力，则该目标终端接收到测量帧后，可以向第一AP反馈测量响应帧，该测量响应帧包括目标终端检测到的测量帧的接收信号强度。若目标终端当前不具备接收信号强度的检测能力，则该目标终端接收到测量帧后，并不会向第一AP反馈携带接收信号强度的测量响应帧。
可以理解的是，目标终端当前不具备接收信号强度的检测能力可能由如下几种情况导致：1、目标终端不支持信号强度的检测标准。2、目标终端支持信号强度的检测标准，但当前由于运行状态(例如经常息屏或处于省电模式)等因素的影响而无法反馈测量响应帧。其中，信号强度的检测标准可以为电气和电子工程师协会(institute of electrical and electronics engineers，IEEE)802.11k标准。
步骤118、第一AP基于目标终端反馈的接收信号强度，向控制器发送检测结果。
第一AP可以基于目标终端反馈的接收信号强度，向控制器发送检测结果，该检测结果用于指示该第一AP是否接收到该目标终端反馈的接收信号强度。
步骤119、控制器基于第一AP在第一时段内发送的检测结果，确定目标终端的检测成功率。
控制器可以对第一AP在第一时段内发送的检测结果进行统计，从而确定目标终端的检测成功率。该检测成功率p可以满足：p＝M1/M0，其中，M1为控制器在该第一时段内接收到的目标检测结果个数，M0为控制器在该第一时段内接收到的检测结果的总数，该目标检测结果用于指示该第一AP接收到目标终端反馈的接收信号强度。
示例的，假设第一AP在第一时段内发送了200个测量帧，目标终端反馈了180个测量响应帧，则第一AP在该第一时段内会向控制器发送200个检测结果，该200个检测结果中包括180个目标检测结果，即M0＝200，M1＝180。相应的，控制器可以计算得到该目标终端的检测成功率p为：p＝180/200＝0.9。
可以理解的是，该第一时段可以为控制器向第一AP发送检测指令之后的时段。该第一时段的时长可以为控制器中预先配置的固定时长，例如，该第一时段可以为1分钟或2分钟。
作为一种可能的示例，为了确保确定出的检测成功率的准确性，控制器可以计算目标终端在多个第一时段内的检测成功率，并且控制器可以在确定该检测成功率趋于稳定后再执行下述步骤121。其中，检测成功率趋于稳定可以是指：相邻两个第一时段的检测成功率的变化量小于阈值，例如5％。
作为另一种可能的示例，为了提高检测成功率的确定效率，控制器还可以在检测到连续接收的失败检测结果的个数大于或等于个数阈值时，直接确定该目标终端的检测成功率为0。其中，该失败检测结果用于指示第一AP未接收到目标终端反馈的接收信号强度。例如，假设该个数阈值为100，若第一AP连续发送100个测量帧后均未接收到该目标终端反馈的测量响应帧，则第一AP会连续向控制器发送100个失败检测结果。控制器进而可以确定该目标终端的检测成功率为0。
步骤120、控制器对多个终端的检测成功率进行处理，得到成功率阈值。
在本申请实施例中，控制器还可以对在第三时段内获取到的多个终端的检测成功率进行处理，以确定成功率阈值。其中，该第三时段可以为位于该第一时段之前的时段。并且，该第三时段可以与该第一时段部分重叠，或者也可以不重叠，本申请实施例对此不做限定。
作为一种可选的实现方式，控制器可以采用箱线图算法对在第三时段内确定出的多个终端的检测成功率进行处理，得到该成功率阈值。
箱线图算法的原理如下：将获取到的大量观察值中，小于QL-1.5IQR或大于QU+1.5IQR的观察值确定为异常值。其中，QL为下四分位数(lower quartile)，表示全部观察值中有四分之一的观察值比QL小。QU为上四分位数(upper quartile)，表示全部观察值中有四分之一的观察值比QU大。IQR为四分位间距(interquartile range)，其为上四分位数QU与下四分位数QL之差，即IQR＝QU-QL。
在本申请实施例中，控制器获取到的终端的检测成功率即为观察值，控制器可以采用箱线图算法对获取到的大量检测成功率进行处理，并可以将QL-1.5IQR作为成功率阈值。
基于上述箱线图算法的原理描述可知，该箱线图算法能够真实、直观地表现出观察值的分布情况，且不会对观察值有限制性要求(例如不要求观察值服从正态分布或近似服从正态分布)。箱线图算法判断异常值的标准以四分位数和四分位距为基础，由于四分位数给出了观察值分布的中心、散布和形状的某种指示，具有一定的鲁棒性，即25％的观察值可以变得任意远而不会很大地扰动四分位数，所以异常值通常不能对这个标准施加影响。鉴于此，箱线图识别异常值的结果比较客观，故本申请实施例采用该箱线图算法确定成功率阈值，以确保该成功率阈值的可靠性。
作为另一种可选的实现方式，控制器还可以采用3σ原则对多个终端的检测成功率进行处理，得到成功率阈值。
可以理解的是，该控制器还可以直接采用预先配置的固定值作为成功率阈值。
步骤121、控制器基于目标终端的检测成功率生成目标终端的终端画像。
目标终端的终端画像可以用于指示该目标终端在当前时刻之后的第二时段内是否具备接收信号强度的检测能力，即该终端画像在当前时刻之后的第二时段内有效。
其中，若目标终端的检测成功率大于或等于成功率阈值，则控制器可以确定目标终端在当前时刻之后的第二时段内具备接收信号强度的检测能力。若目标终端的检测成功率小于成 功率阈值，则控制器可以确定目标终端在当前时刻之后的第二时段内不具备接收信号强度的检测能力。
可以理解的是，该第二时段的时长可以为控制器中预先配置的固定时长，例如，该第二时长可以为三个月。
步骤122、控制器基于目标终端的终端画像，判断目标终端当前是否具备接收信号强度的检测能力。
控制器若确定目标终端的终端画像有效，则可以基于该目标终端的终端画像，判断目标终端当前是否具备接收信号强度的检测能力。若控制器基于该终端画像确定目标终端当前不具备接收信号强度的检测能力，则可以结束操作，即控制器无需启动对目标终端的测量。若控制器基于该终端画像确定目标终端当前具备接收信号强度的检测能力，则可以执行上述步骤101。也即是，控制器可以在确定目标终端当前具备接收信号强度的检测能力时，再向与该目标终端关联的第一AP发送针对该目标终端的强度测量指令。由此，可以避免当目标终端不具备接收信号强度的检测能力时，控制器向第一AP发送强度测量指令而导致的无效测量。
示例的，控制器中存储的各个终端的终端画像可以如表2所示。若目标终端为MAC地址为00:11:22:33:44:55的终端，且当前时间为2020-11-30，则控制器基于表2所示的终端画像可以确定该目标终端当前具备接收信号强度的检测能力，并可以执行上述步骤101。若目标终端为MAC地址为aa:bb:cc:dd:ee:ff的终端，则控制器基于表2所示的终端画像可以确定该目标终端当前不具备接收信号强度的检测能力，并可以结束操作。
表2
终端的MAC地址 终端画像 过期时间
00:11:22:33:44:55 具备接收信号强度的检测能力 2020-12-1
aa:bb:cc:dd:ee:ff 不具备接收信号强度的检测能力 2020-12-1
33:44:55:66:77:88 画像已经过期 2020-11-2
假设信号强度的检测标准为IEEE 802.11k标准，现网大约60％-70％的终端支持该802.11K标准，剩余的30％-40％的终端不支持该802.11k标准。本申请实施例提供的方法在确定目标终端具备接收信号强度的检测能力后再启动测量，理论上至少可以将下行测量的空口开销降低30％以上。
可以理解的是，本申请实施例提供的方法的步骤的先后顺序可以进行适当调整，步骤也可以根据情况进行相应增减。例如，步骤103可以在步骤102之前执行，步骤108可以在步骤107之前执行。步骤110和步骤111可以根据情况删除，步骤112至步骤114中的任一步骤可以根据情况删除，步骤112至步骤114中各个步骤的执行顺序可以根据情况调节。任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化的方法，都应涵盖在本申请的保护范围之内，因此不再赘述。
还可以理解的是，上述实施例是以AP与终端之间的路径损耗为下行链路的路径损耗为例进行的说明。当然，该路径损耗也可以是AP与终端之间的上行链路的路径损耗，该上行链路的路径损耗可以基于终端的发射功率以及AP检测到的终端发送的信号的强度(例如上行链路的RSSI)得到。其中，若需要第二AP检测目标终端发送的信号的强度，则第二AP可以将其工作信道切换至目标信道(即第一AP与目标终端关联时所采用的信道)以接收该目标终端发 送的信号，并检测接收到的信号的强度。
综上所述，本申请实施例提供了一种网络拓扑的识别方法，控制器确定出的网络拓扑不仅包括两个AP之间的路径损耗，还包括每个AP与终端之间的路径损耗，即该网络拓扑为3D网络拓扑。由于该3D网络拓扑中，AP与终端之间的路径损耗不仅可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度，因此可以确保控制器确定出的网络拓扑的可靠性较高。进而，可以确保基于该网络拓扑对AP进行管控(例如射频调优)时的可靠性较高。
此外，本申请实施例提供的方法至少还包括如下有益效果：
1、控制器能够识别出高挂AP，以及AP之间存在遮挡物等非理想的部署场景，因此可以确保基于识别出的部署场景进行射频调优后，能够为终端提供更好的信号质量，更低的干扰，以及更好的业务体验。
2、控制器可以基于AP与终端之间的路径损耗确定AP的理想覆盖范围，并可以基于该理想覆盖范围进行功率调优。由此，可以在保证AP的信号覆盖质量的前提下避免AP的功率过大而造成的干扰。
3、控制器基于3D网络拓扑为AP分配信道，可以有效避免同频干扰。
4、控制器确定出的3D网络拓扑中AP与终端之间的路径损耗可以为下行链路的路径损耗，由于该下行链路的路径损耗是影响终端业务体验的重要因素，因此基于该下行链路的路径损耗进行射频调优可以有效改善终端的业务体验。
5、控制器可以基于终端画像对当前具备信号强度的检测能力的终端进行测量，由此可以避免无效测量而浪费网络资源。
图15是本申请实施例提供的一种控制器的结构示意图，该控制器可以应用于如图1或图2所示的系统中，且可以用于实现上述方法实施例提供的网络拓扑的识别方法。参考图15，该控制器包括：
第一确定模块201，用于确定第一接入点AP、第二AP和目标终端之间的网络拓扑。其中，该目标终端与第一AP关联，第二AP为该第一AP的邻居AP，该网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗，该第一路径损耗是第一AP与目标终端之间的路径损耗，该第二路径损耗是第二AP与目标终端之间的路径损耗，该第三路径损耗是第一AP与第二AP之间的路径损耗。
该第一确定模块201的功能实现可以参考上述方法实施例中步骤109的相关描述。
可选地，该第一确定模块201，还可以用于将该第一AP和该第一AP的多个邻居AP中与该目标终端之间的路径损耗最小的AP确定为该目标终端归属的归属AP；以及基于归属于该归属AP的终端确定该归属AP的理想覆盖范围，该归属AP的理想覆盖范围用于进行射频调优。
该第一确定模块201的功能实现还可以参考上述方法实施例中步骤110和步骤111的相关描述。
可选地，该第一确定模块201还可以用于：对于该第一AP和该第二AP中的任一AP，基于该任一AP与多个终端之间的路径损耗，确定该任一AP是否为高挂AP，该高挂AP是指与该多个终端之间的距离大于距离阈值，或与该多个终端之间存在遮挡物的AP。
该第一确定模块201的功能实现还可以参考上述方法实施例中步骤112的相关描述。
可选地，该第一确定模块201可以用于：若该任一AP与位于该任一AP的理想覆盖范围内 的终端之间的路径损耗大于第一损耗阈值，则确定该任一AP为高挂AP。
可选地，该第一确定模块201还可以用于：若该第一AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，该第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于该第二损耗阈值，且该第一AP与该第二AP之间的第三路径损耗大于第三损耗阈值，则确定该第一AP和该第二AP之间存在遮挡物。
该第一确定模块201的功能实现还可以参考上述方法实施例中步骤113的相关描述。
可选地，如图15所示，该控制器还可以包括：
调优模块202，用于基于该第一AP、该第二AP和该目标终端之间的网络拓扑，对该第一AP和该第二AP中的至少一个AP进行射频调优。该调优模块202的功能实现可以参考上述方法实施例中步骤114的相关描述。
可选地，如图16所示，该控制器还可以包括：
功率调节模块203，用于对于该第一AP和该第二AP中的任一AP，基于该任一AP与位于该任一AP的理想覆盖范围内的终端之间的路径损耗，调节该任一AP的发射功率，使得位于该任一AP的理想覆盖范围内的终端检测到的该任一AP发送的信号的强度大于强度阈值。
该功率调节模块203的功能实现可以参考上述方法实施例中步骤114的相关描述。
可选地，如图16所示，该控制器还可以包括：
信道分配模块204，用于为该第一AP分配第一频率的信道，并为该第二AP分配第二频率的信道。其中，若该第一AP与位于该第二AP的理想覆盖范围内的终端之间的路径损耗大于第四损耗阈值，且该第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗大于该第四损耗阈值，则该第一频率与该第二频率的频率差小于第一频率阈值；
若该第一AP与位于该第二AP的理想覆盖范围内的终端之间的路径损耗小于第五损耗阈值，或者，该第二AP与位于该第一AP的理想覆盖范围内的终端之间的路径损耗小于该第五损耗阈值，则该第一频率与该第二频率的频率差大于第二频率阈值；该第四损耗阈值大于或等于该第五损耗阈值，该第一频率阈值小于或等于该第二频率阈值。
该信道分配模块204的功能实现也可以参考上述方法实施例中步骤114的相关描述。
可以理解的是，上述功率调节模块203和信道分配模块204均可以为调优模块202中的子模块，即该调优模块202可以实现功率调节模块203和信道分配模块204的功能。
可选地，如图15和图16所示，该控制器还可以包括：
接收模块205，用于接收第一AP发送的第一接收信号强度和第二接收信号强度，该第一接收信号强度和该第二接收信号强度均由该目标终端发送至第一AP。其中，该第一接收信号强度为该目标终端检测到的该第一AP发送的第一测量帧的强度，该第一测量帧携带该第一AP的BSSID，该第一接收信号强度用于确定该第一路径损耗；该第二接收信号强度为该目标终端检测到的该第二AP发送的第二测量帧的强度，该第二测量帧携带该第一AP的BSSID，该第二接收信号强度用于确定该第二路径损耗。
该接收模块205的功能实现可以参考上述方法实施例中步骤107的相关描述。
可选地，如图15和图16所示，该控制器还可以包括：
发送模块206，用于在该接收模块205接收第一AP发送的第一接收信号强度和第二接收信号强度之前，向该第一AP发送检测指令，该检测指令用于指示该第一AP触发该目标终端进行接收信号强度的检测。该发送模块206的功能实现可以参考上述方法实施例中步骤116的相关描述。
第二确定模块207，用于基于该第一AP在第一时段内发送的检测结果，确定该目标终端的检测成功率，以及若该检测成功率大于或等于成功率阈值，则确定该目标终端在当前时刻之后的第二时段内具备接收信号强度的检测能力，其中，该检测结果用于指示该第一AP是否接收到该目标终端反馈的接收信号强度；该检测成功率为在该第一时段内接收到的目标检测结果个数，与在该第一时段内接收到的检测结果的总数的比值，该目标检测结果用于指示该第一AP接收到该目标终端反馈的接收信号强度。
该第二确定模块207的功能实现可以参考上述方法实施例中步骤118、步骤119和步骤121的相关描述。
该发送模块206，还可以用于基于该目标终端具备接收信号强度的检测能力，向该第一AP发送针对该目标终端的强度测量指令，该强度测量指令用于指示该第一AP获取该第一接收信号强度和该第二接收信号强度。
该发送模块206的功能实现还可以参考上述方法实施例中步骤101的相关描述。
可选地，如图15和图16所示，该控制器还可以包括：
处理模块208，用于采用箱线图算法对在第三时段内确定出的多个终端的检测成功率进行处理，得到该成功率阈值。该处理模块208的功能实现还可以参考上述方法实施例中步骤120的相关描述。
可选地，该第一AP具有包括该第二AP在内的多个邻居AP，该多个邻居AP按照与该第一AP之间的路径损耗由小到大的顺序排序后，该第二AP的排列序号小于或等于N，该N为小于或等于该多个邻居AP的总数的正整数。
综上所述，本申请实施例提供了一种控制器，该控制器确定出的网络拓扑不仅包括两个AP之间的路径损耗，还包括每个AP与终端之间的路径损耗，即该网络拓扑为3D网络拓扑。由于该3D网络拓扑中，AP与终端之间的路径损耗不仅可以准确反映AP与终端之间的链路的信号传输性能，且可以准确反映不同AP发送的下行信号之间的干扰程度，因此可以确保控制器确定出的网络拓扑的可靠性较高。进而，可以确保基于该网络拓扑对AP进行管控(例如射频调优)时的可靠性较高。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上文描述的控制器以及各模块的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
应理解的是，本申请实施例提供的控制器可以用专用集成电路(application-specific integrated circuit，ASIC)实现，或可编程逻辑器件(programmable logic device，PLD)实现，上述PLD可以是复杂程序逻辑器件(complex programmable logical device，CPLD)，现场可编程门阵列(field-programmable gate array，FPGA)，通用阵列逻辑(generic array logic，GAL)或其任意组合。或者，也可以通过软件实现上述方法实施例提供的网络拓扑的识别方法，当通过软件实现上述方法实施例提供的网络拓扑的识别方法时，上述控制器中的各个模块也可以为软件模块。
图17是本申请实施例提供的又一种控制器的结构示意图，该控制器可以应用于图1或图2所示的系统中。参考图17，该控制器可以包括：处理器301、存储器302、网络接口303和总线304。其中，总线304用于连接处理器301、存储器302和网络接口303。通过网络接口303(可以是有线或者无线)可以实现与其他设备之间的通信连接。存储器302中存储有计算机程序3021，该计算机程序3021用于实现各种应用功能。
应理解，在本申请实施例中，处理器301可以是CPU，该处理器301还可以是其他通用处理器、数字信号处理器(digital signal processing，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field-programmable gate array，FPGA)、通用阵列逻辑(generic array logic，GAL)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等，或上述处理器的任意组合。通用处理器可以是微处理器或者是任何常规的处理器等。
存储器302可包括易失性存储器，非易失性存储器，或其组合。其中，非易失性存储器可以包括只读存储器(read-only memory，ROM)、可编程只读存储器(programmable ROM，PROM)、可擦除可编程只读存储器(erasable PROM，EPROM)、电可擦除可编程只读存储器(electrically EPROM，EEPROM)、闪存或其任意组合。易失性存储器可以包括随机存取存储器(random access memory，RAM)，例如静态随机存取存储器(static RAM，SRAM)、动态随机存取存储器(DRAM)、同步动态随机存取存储器(synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(double data date SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器(enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synchlink DRAM，SLDRAM)、直接内存总线随机存取存储器(direct rambus RAM，DR RAM)或其任意组合。
总线304除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线304。
处理器301可以被配置为执行存储器302中存储的计算机程序3021来实现上述方法实施例中由控制器执行的步骤。
图18是本申请实施例提供的再一种控制器的结构示意图，该控制器可以应用于图1或图2所示的系统中。如图18所示，该控制器包括主控板401和接口板402。
主控板401也称为主处理单元(main processing unit，MPU)或路由处理卡(route processor card)，主控板401用于对控制器中各个组件进行控制和管理，包括路由计算、设备管理、设备维护和协议处理等功能。主控板401包括：中央处理器4011和存储器4012。
接口板402也称为线路接口单元卡(line processing unit，LPU)、线卡(line card)或业务板。接口板402用于提供各种业务接口并实现数据包的转发。业务接口包括而不限于以太网接口、基于SONET/SDH的数据包(packet over SONET/SDH，POS)接口等。SONET是指同步光纤网络(synchronous optical network)，SDH是指同步数字体系(synchronous digital hierarchy)。以太网接口例如是灵活以太网业务接口(flexible Ethernet clients，FlexE Clients)。接口板402包括：中央处理器4021、网络处理器4022、转发表项存储器4024和物理接口卡(physical interface card，PIC)4023。
接口板402上的中央处理器4021用于对接口板402进行控制管理并与主控板401上的中央处理器4011进行通信。
网络处理器4022用于实现报文的转发处理。网络处理器4022的形态可以是转发芯片。转发芯片可以是网络处理器(network processor，NP)。在一些实施例中，转发芯片可以通过专用集成电路(application-specific integrated circuit，ASIC)或现场可编程门阵列(field programmable gate array，FPGA)实现。具体而言，网络处理器4022用于基于转发表项存储器4024保存的转发表转发接收到的报文，如果报文的目的地址为控制器的地址，则将该报文上 送至CPU(如中央处理器4021)处理；如果报文的目的地址不是控制器的地址，则根据该目的地址从转发表中查找到该目的地址对应的下一跳和出接口，将该报文转发到该目的地址对应的出接口。其中，上行报文的处理可以包括：报文入接口的处理，转发表查找；下行报文的处理可以包括：转发表查找等等。在一些实施例中，中央处理器也可执行转发芯片的功能，比如基于通用CPU实现软件转发，从而接口板中不需要转发芯片。
物理接口卡4023用于实现物理层的对接功能，原始的流量由此进入接口板402，以及处理后的报文从该物理接口卡4023发出。物理接口卡4023也称为子卡，可安装在接口板402上，负责将光电信号转换为报文并对报文进行合法性检查后转发给网络处理器4022处理。在一些实施例中，中央处理器4021也可执行网络处理器4022的功能，比如基于通用CPU实现软件转发，从而物理接口卡4023中不需要网络处理器4022。
可选地，控制器包括多个接口板，例如控制器还包括接口板403，接口板403包括：中央处理器4031、网络处理器4032、转发表项存储器4034和物理接口卡4033。接口板403中各部件的功能和实现方式与接口板402相同或相似，在此不再赘述。
可选地，控制器还包括交换网板404。交换网板404也可以称为交换网板单元(switch fabric unit，SFU)。在网络管理设备有多个接口板的情况下，交换网板404用于完成各接口板之间的数据交换。例如，接口板402和接口板403之间可以通过交换网板404通信。
主控板401和接口板耦合。例如。主控板401、接口板402和接口板403，以及交换网板404之间通过系统总线与系统背板相连实现互通。在一种可能的实现方式中，主控板401和接口板402及接口板403之间建立进程间通信协议(inter-process communication，IPC)通道，主控板401和接口板402及接口板403之间通过IPC通道进行通信。
在逻辑上，控制器包括控制面和转发面，控制面包括主控板401和中央处理器4011，转发面包括执行转发的各个组件，比如转发表项存储器4024、物理接口卡4023和网络处理器4022。控制面执行路由器、生成转发表、处理信令和协议报文、配置与维护网络设备的状态等功能，控制面将生成的转发表下发给转发面，在转发面，网络处理器4022基于控制面下发的转发表对物理接口卡4023收到的报文查表转发。控制面下发的转发表可以保存在转发表项存储器4024中。在有些实施例中，控制面和转发面可以完全分离，不在同一网络设备上。
值得说明的是，主控板可能有一块或多块，有多块的时候可以包括主用主控板和备用主控板。接口板可能有一块或多块，网络管理设备的数据处理能力越强，提供的接口板越多。接口板上的物理接口卡也可以有一块或多块。交换网板可能没有，也可能有一块或多块，有多块的时候可以共同实现负荷分担冗余备份。在集中式转发架构下，网络管理设备可以不需要交换网板，接口板承担整个系统的业务数据的处理功能。在分布式转发架构下，网络管理设备可以有至少一块交换网板，通过交换网板实现多块接口板之间的数据交换，提供大容量的数据交换和处理能力。所以，分布式架构的网络管理设备的数据接入和处理能力要大于集中式架构的网络管理设备。可选地，网络管理设备的形态也可以是只有一块板卡，即没有交换网板，接口板和主控板的功能集成在该一块板卡上，此时接口板上的中央处理器和主控板上的中央处理器在该一块板卡上可以合并为一个中央处理器，执行两者叠加后的功能，这种形态网络管理设备的数据交换和处理能力较低(例如，低端交换机或路由器等网络设备)。具体采用哪种架构，取决于具体的组网部署场景，此处不做任何限定。
本申请实施例还提供了一种计算机可读存储介质，该计算机可读存储介质中存储有指令， 该指令由处理器执行以实现上述方法实施例提供的网络拓扑的识别方法。
本申请实施例还提供了一种包含指令的计算机程序产品，当该计算机程序产品在计算机上运行时，使得计算机执行上述方法实施例提供的网络拓扑的识别方法。
本申请实施例还提供了一种无线通信系统，如图1和图2所示，该系统包括：控制器01，以及与该控制器01连接的多个AP 02。其中，该控制器01可以为图15至图17中任一附图所示的控制器。示例的，该控制器01可以为AC。
上述实施例，可以全部或部分地通过软件、硬件、固件或其任意组合来实现。当使用软件或固件实现时，上述实施例可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载或执行所述计算机程序指令时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以为通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站移动终端、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、双绞线)或无线(例如红外、无线、微波等)方式向另一个网站移动终端、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何介质或者是包含一个或多个介质集合的服务器、数据中心等数据存储设备。所述介质可以是磁性介质(例如，软盘、硬盘、磁带)、光介质(例如，光盘)、或者半导体介质。半导体介质可以是固态硬盘(solid state drive，SSD)。
本申请中术语“至少一个”的含义是指一个或多个，本申请中术语“多个”的含义是指两个或两个以上，本文中术语“系统”和“网络”经常可互换使用。在本文中提及的“和/或”，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。字符“/”一般表示前后关联对象是一种“或”的关系。
以上所述仅为本申请的可选实施例，并不用以限制本申请。本申请的保护范围以权利要求为准。

Claims (28)

  1. 一种网络拓扑的识别方法，其特征在于，所述方法包括：
    确定第一接入点(AP)、第二AP和目标终端之间的网络拓扑，其中，所述目标终端与所述第一AP关联，所述第二AP为所述第一AP的邻居AP，所述网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗，所述第一路径损耗是所述第一AP与所述目标终端之间的路径损耗，所述第二路径损耗是所述第二AP与所述目标终端之间的路径损耗，所述第三路径损耗是所述第一AP与所述第二AP之间的路径损耗。
  2. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    将所述第一AP和所述第一AP的多个邻居AP中与所述目标终端之间的路径损耗最小的AP确定为所述目标终端归属的归属AP；
    基于归属于所述归属AP的终端确定所述归属AP的理想覆盖范围，所述归属AP的理想覆盖范围用于进行射频调优。
  3. 根据权利要求1或2所述的方法，其特征在于，所述方法还包括：
    对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，所述高挂AP是指与所述多个终端之间的距离大于距离阈值，或与所述多个终端之间存在遮挡物的AP。
  4. 根据权利要求2所述的方法，其特征在于，所述方法还包括：
    对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，所述高挂AP是指与所述多个终端之间的距离大于距离阈值，或与所述多个终端之间存在遮挡物的AP；
    其中，所述多个终端为位于所述任一AP的理想覆盖范围内的终端；所述基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，包括：
    若所述任一AP与位于所述任一AP的理想覆盖范围内的终端之间的路径损耗大于第一损耗阈值，则确定所述任一AP为高挂AP。
  5. 根据权利要求2或4所述的方法，其特征在于，所述方法还包括：
    若所述第一AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于所述第二损耗阈值，且所述第一AP与所述第二AP之间的第三路径损耗大于第三损耗阈值，则确定所述第一AP和所述第二AP之间存在遮挡物。
  6. 根据权利要求1至5任一所述的方法，其特征在于，所述方法还包括：
    基于所述第一AP、所述第二AP和所述目标终端之间的网络拓扑，对所述第一AP和所述第二AP中的至少一个AP进行射频调优。
  7. 根据权利要求2或4或5所述的方法，其特征在于，所述方法还包括：
    对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与位于所述任一AP的理想 覆盖范围内的终端之间的路径损耗，调节所述任一AP的发射功率，使得位于所述任一AP的理想覆盖范围内的终端检测到的所述任一AP发送的信号的强度大于强度阈值。
  8. 根据权利要求2，4，5和7中任一所述的方法，其特征在于，所述方法还包括：
    为所述第一AP分配第一频率的信道，并为所述第二AP分配第二频率的信道；
    其中，若所述第一AP与位于所述第二AP的理想覆盖范围内的终端之间的路径损耗大于第四损耗阈值，且所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗大于所述第四损耗阈值，则所述第一频率与所述第二频率的频率差小于第一频率阈值；
    若所述第一AP与位于所述第二AP的理想覆盖范围内的终端之间的路径损耗小于第五损耗阈值，或者，所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于所述第五损耗阈值，则所述第一频率与所述第二频率的频率差大于第二频率阈值；
    所述第四损耗阈值大于或等于所述第五损耗阈值，所述第一频率阈值小于或等于所述第二频率阈值。
  9. 根据权利要求1至8任一所述的方法，其特征在于，所述方法还包括：
    接收所述第一AP发送的第一接收信号强度和第二接收信号强度，所述第一接收信号强度和所述第二接收信号强度均由所述目标终端发送至所述第一AP；
    其中，所述第一接收信号强度为所述目标终端检测到的所述第一AP发送的第一测量帧的强度，所述第一测量帧携带所述第一AP的基本服务集标识(BSSID)，所述第一接收信号强度用于确定所述第一路径损耗；
    所述第二接收信号强度为所述目标终端检测到的所述第二AP发送的第二测量帧的强度，所述第二测量帧携带所述第一AP的BSSID，所述第二接收信号强度用于确定所述第二路径损耗。
  10. 根据权利要求9所述的方法，其特征在于，在接收所述第一AP发送的第一接收信号强度和第二接收信号强度之前，所述方法还包括：
    向所述第一AP发送检测指令，所述检测指令用于指示所述第一AP触发所述目标终端进行接收信号强度的检测；
    基于所述第一AP在第一时段内发送的检测结果，确定所述目标终端的检测成功率，其中，所述检测结果用于指示所述第一AP是否接收到所述目标终端反馈的接收信号强度；
    若所述检测成功率大于或等于成功率阈值，则确定所述目标终端在当前时刻之后的第二时段内具备接收信号强度的检测能力；
    基于所述目标终端具备接收信号强度的检测能力，向所述第一AP发送针对所述目标终端的强度测量指令，所述强度测量指令用于指示所述第一AP获取所述第一接收信号强度和所述第二接收信号强度；
    其中，所述检测成功率为在所述第一时段内接收到的目标检测结果个数，与在所述第一时段内接收到的检测结果的总数的比值，所述目标检测结果用于指示所述第一AP接收到所述目标终端反馈的接收信号强度。
  11. 根据权利要求10所述的方法，其特征在于，所述方法还包括：
    采用箱线图算法对在第三时段内确定出的多个终端的检测成功率进行处理，得到所述成功率阈值。
  12. 根据权利要求1至11任一所述的方法，其特征在于，所述第一AP具有包括所述第二AP在内的多个邻居AP，所述多个邻居AP按照与所述第一AP之间的路径损耗由小到大的顺序排序后，所述第二AP的排列序号小于或等于N，所述N为小于或等于所述多个邻居AP的总数的正整数。
  13. 一种控制器，其特征在于，所述控制器包括：
    第一确定模块，用于确定第一接入点(AP)、第二AP和目标终端之间的网络拓扑，其中，所述目标终端与所述第一AP关联，所述第二AP为所述第一AP的邻居AP，所述网络拓扑包括：第一路径损耗、第二路径损耗以及第三路径损耗，所述第一路径损耗是所述第一AP与所述目标终端之间的路径损耗，所述第二路径损耗是所述第二AP与所述目标终端之间的路径损耗，所述第三路径损耗是所述第一AP与所述第二AP之间的路径损耗。
  14. 根据权利要求13所述的控制器，其特征在于，所述第一确定模块还用于：
    将所述第一AP和所述第一AP的多个邻居AP中与所述目标终端之间的路径损耗最小的AP确定为所述目标终端归属的归属AP；
    基于归属于所述归属AP的终端确定所述归属AP的理想覆盖范围，所述归属AP的理想覆盖范围用于进行射频调优。
  15. 根据权利要求13或14所述的控制器，其特征在于，所述第一确定模块还用于：
    对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，所述高挂AP是指与所述多个终端之间的距离大于距离阈值，或与所述多个终端之间存在遮挡物的AP。
  16. 根据权利要求14所述的控制器，其特征在于，所述第一确定模块还用于：
    对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，所述高挂AP是指与所述多个终端之间的距离大于距离阈值，或与所述多个终端之间存在遮挡物的AP；
    其中，所述多个终端为位于所述任一AP的理想覆盖范围内的终端；所述基于所述任一AP与多个终端之间的路径损耗，确定所述任一AP是否为高挂AP，包括：
    若所述任一AP与位于所述任一AP的理想覆盖范围内的终端之间的路径损耗大于第一损耗阈值，则确定所述任一AP为高挂AP。
  17. 根据权利要求14或16所述的控制器，其特征在于，所述第一确定模块还用于：
    若所述第一AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于第二损耗阈值，所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于所述第二损耗阈值，且所述第一AP与所述第二AP之间的第三路径损耗大于第三损耗阈值，则确定所述第一AP和所述第二AP之间存在遮挡物。
  18. 根据权利要求13至17任一所述的控制器，其特征在于，所述控制器还包括：
    调优模块，用于基于所述第一AP、所述第二AP和所述目标终端之间的网络拓扑，对所述第一AP和所述第二AP中的至少一个AP进行射频调优。
  19. 根据权利要求14或16或17所述的控制器，其特征在于，所述控制器还包括：
    功率调节模块，用于对于所述第一AP和所述第二AP中的任一AP，基于所述任一AP与位于所述任一AP的理想覆盖范围内的终端之间的路径损耗，调节所述任一AP的发射功率，使得位于所述任一AP的理想覆盖范围内的终端检测到的所述任一AP发送的信号的强度大于强度阈值。
  20. 根据权利要求14，16，17和19中任一所述的控制器，其特征在于，所述控制器还包括：
    信道分配模块，用于为所述第一AP分配第一频率的信道，并为所述第二AP分配第二频率的信道；
    其中，若所述第一AP与位于所述第二AP的理想覆盖范围内的终端之间的路径损耗大于第四损耗阈值，且所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗大于所述第四损耗阈值，则所述第一频率与所述第二频率的频率差小于第一频率阈值；
    若所述第一AP与位于所述第二AP的理想覆盖范围内的终端之间的路径损耗小于第五损耗阈值，或者，所述第二AP与位于所述第一AP的理想覆盖范围内的终端之间的路径损耗小于所述第五损耗阈值，则所述第一频率与所述第二频率的频率差大于第二频率阈值；
    所述第四损耗阈值大于或等于所述第五损耗阈值，所述第一频率阈值小于或等于所述第二频率阈值。
  21. 根据权利要求13至20任一所述的控制器，其特征在于，所述控制器还包括：
    接收模块，用于接收所述第一AP发送的第一接收信号强度和第二接收信号强度，所述第一接收信号强度和所述第二接收信号强度均由所述目标终端发送至所述第一AP；
    其中，所述第一接收信号强度为所述目标终端检测到的所述第一AP发送的第一测量帧的强度，所述第一测量帧携带所述第一AP的基本服务集标识(BSSID)，所述第一接收信号强度用于确定所述第一路径损耗；
    所述第二接收信号强度为所述目标终端检测到的所述第二AP发送的第二测量帧的强度，所述第二测量帧携带所述第一AP的BSSID，所述第二接收信号强度用于确定所述第二路径损耗。
  22. 根据权利要求21所述的控制器，其特征在于，所述控制器还包括：
    发送模块，用于在所述接收模块接收所述第一AP发送的第一接收信号强度和第二接收信号强度之前，向所述第一AP发送检测指令，所述检测指令用于指示所述第一AP触发所述目标终端进行接收信号强度的检测；
    第二确定模块，用于基于所述第一AP在第一时段内发送的检测结果，确定所述目标终端的检测成功率，以及若所述检测成功率大于或等于成功率阈值，则确定所述目标终端在当前时刻之后的第二时段内具备接收信号强度的检测能力，其中，所述检测结果用于指示所述第 一AP是否接收到所述目标终端反馈的接收信号强度；
    所述发送模块，还用于基于所述目标终端具备接收信号强度的检测能力，向所述第一AP发送针对所述目标终端的强度测量指令，所述强度测量指令用于指示所述第一AP获取所述第一接收信号强度和所述第二接收信号强度；
    其中，所述检测成功率为在所述第一时段内接收到的目标检测结果个数，与在所述第一时段内接收到的检测结果的总数的比值，所述目标检测结果用于指示所述第一AP接收到所述目标终端反馈的接收信号强度。
  23. 根据权利要求22所述的控制器，其特征在于，所述控制器还包括：
    处理模块，用于采用箱线图算法对在第三时段内确定出的多个终端的检测成功率进行处理，得到所述成功率阈值。
  24. 根据权利要求13至23任一所述的控制器，其特征在于，所述第一AP具有包括所述第二AP在内的多个邻居AP，所述多个邻居AP按照与所述第一AP之间的路径损耗由小到大的顺序排序后，所述第二AP的排列序号小于或等于N，所述N为小于或等于所述多个邻居AP的总数的正整数。
  25. 一种控制器，其特征在于，所述控制器包括：存储器，处理器及存储在所述存储器上并可在所述处理器上运行的计算机程序，所述处理器执行所述计算机程序时实现如权利要求1至12任一所述的网络拓扑的识别方法。
  26. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质中存储有指令，所述指令由处理器执行以实现如权利要求1至12任一所述的网络拓扑的识别方法。
  27. 一种无线通信系统，其特征在于，所述系统包括：多个接入点(AP)，以及与所述多个AP连接的如权利要求13至25任一所述的控制器。
  28. 一种计算机程序产品，其特征在于，所述计算机程序产品包含指令，所述计算机程序产品在计算机上运行时，使得计算机执行如权利要求1至12任一所述的网络拓扑的识别方法。
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