Station roaming method and apparatus, access controller, and medium

Abstract

The present application provides a station (STA) roaming method and apparatus, an access controller (AC), and a medium. The method is applied to a first AC, and the method comprises: in response to a first STA being connected to any access point (AP) managed by the first AC, if it is determined that the first STA is not associated with the first AC, sending a roaming query request to at least one neighboring AC, wherein the at least one neighboring AC is an AC of which the signal coverage area is adjacent to that of the first AC; and if response information sent by a target neighboring AC is received, enabling the first STA to roam between the first AC and the target neighboring AC.

Description

Wireless terminal roaming method, apparatus, access controller and medium

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese patent application No. 202411052409.8, filed on August 01, 2024, and entitled "Wireless terminal roaming method, apparatus, access controller, medium and program product", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of wireless communication, and in particular to a wireless terminal roaming method, apparatus, access controller and medium. BACKGROUND

[0004] Wireless terminal (Station, STA for short) roaming between access controllers (Access Controller, AC for short) involves inter-AC interaction, and a tunnel needs to be established between the roaming-in AC and the roaming-out AC to realize roaming. In the scenario of a large number of distributed AC networking, by configuring a roaming group, a plurality of specified ACs are added to the same roaming group, so that the STA can roam between the ACs. When the STA accesses any access point (Access Point, AP for short), the AC to which the AP belongs, i.e., the roaming-in AC, sends a query request to each AC in the same group, and the AC in the same group responds to the query request if it is determined that the STA was previously on the AC, so that the STA performs inter-AC roaming between the roaming-out AC and the roaming-in AC. SUMMARY

[0005] The present application provides a wireless terminal roaming method, apparatus, access controller, medium and program product.

[0006] In a first aspect, the present application provides a wireless terminal roaming method, which is applied to a first access controller (AC), and the method comprises:

[0007] In response to a first wireless terminal (STA) accessing any wireless access point (AP) managed by the first AC, if it is determined that the first STA is not associated with the first AC, a roaming query request is sent to at least one neighbor AC respectively; the at least one neighbor AC is an AC whose signal coverage range is adjacent to the signal coverage range of the first AC; and

[0008] If the response information sent by a target neighbor AC is received, the first STA is caused to perform roaming between the first AC and the target neighbor AC.

[0009] In some embodiments, the sending the roaming query request to at least one neighbor AC respectively comprises:

[0010] If it is determined that the type of the access AP is a border AP, or it is determined that the type of the access AP is an inland AP and the first STA accesses the access AP using a re-association request frame, the roaming query request is sent to all neighbor ACs of the first AC respectively.

[0011] In some embodiments, the sending the roaming query request to at least one neighbor AC respectively comprises:

[0012] If it is determined that the type of the access AP is a border AP, the roaming query request is sent to each neighbor AC having a mapping relationship with the access AP respectively.

[0013] In some embodiments, the method further comprises:

[0014] If it is determined that the type of the access AP is an inland AP and the first STA accesses the access AP using an association request frame, the first STA is associated according to a first association strategy.

[0015] In some embodiments, after the sending the roaming query request to at least one neighbor AC respectively, the method further comprises:

[0016] If the response information is not received within a second preset time period, the first STA is associated according to a first association strategy.

[0017] In some embodiments, the method further comprises:

[0018] The at least one neighbor AC corresponding to the first AC is determined through an exchange of foreign AP information within a first preset time period after the first AC is powered on;

[0019] And / or,

[0020] The at least one neighbor AC corresponding to the first AC is determined through a roaming trajectory learning within a first preset time period after the first AC is powered on.

[0021] In some embodiments, a plurality of ACs are included in a roaming domain virtual local area network (VLAN), and the plurality of ACs include the first AC. The at least one neighbor AC corresponding to the first AC is determined through an exchange of foreign AP information within a first preset time period after the first AC is powered on, comprising:

[0022] The following operations are performed within the first preset time period after the first AC is powered on until the first preset time period is reached, the following operations comprising:

[0023] obtain neighbor AP information reported by the first AP managed by the first AC; the neighbor AP information comprises AP identifiers corresponding to each neighbor AP identified by the first AP;

[0024] when the neighbor AP information contains a foreign AP identifier not belonging to the first AC, add the foreign AP identifier to a foreign AP list, and broadcast the foreign AP list in the roaming domain VLAN; and

[0025] if response information sent by a second AC for the foreign AP list is received, determine that the second AC is a neighbor AC; wherein the response information is sent by the second AC to the first AC when it is determined that the foreign AP list contains an AP identifier belonging to the second AC.

[0026] In some embodiments, the roaming domain VLAN comprises a plurality of ACs, and the plurality of ACs comprises the first AC, and the at least one neighbor AC corresponding to the first AC is determined by a roaming track learning manner within the first preset time period after the first AC is powered on, comprising:

[0027] the following operations are performed within the first preset time period after the first AC is powered on until the first preset time period is reached, and the following operations comprise:

[0028] in response to a second STA accessing a first AP managed by the first AC, if it is determined that the second STA is not associated with the first AC, broadcast a roaming query request in the roaming domain VLAN;

[0029] if response information sent by a third AC is received, determine that the third AC is a neighbor AC.

[0030] In some embodiments, further comprising:

[0031] if the response information sent by the third AC is received within a second preset time period, make the second STA roam between the first AC and the third AC; and

[0032] if no response information is received within the second preset time period, associate with the second STA according to a first association strategy.

[0033] In some embodiments, the method further comprises: determining the type of the first AP and writing the type of the first AP into an internal AP list in the process of determining the at least one neighbor AC corresponding to the first AC; the type is a border AP or an inland AP, each neighbor AP of the inland AP belongs to the APs managed by the first AC, and at least one of the neighbor APs of the border AP does not belong to the APs managed by the first AC; and

[0034] If the type of the first AP is the border AP, the mapping relationship between the first AP and the corresponding neighbor AC is stored; the corresponding neighbor AC is an AC to which a neighbor AP of the first AP does not belong.

[0035] In some embodiments, if the at least one neighbor AC corresponding to the first AC is determined by exchanging foreign AP information, the type of the first AP is determined in the process of determining the at least one neighbor AC corresponding to the first AC, comprising:

[0036] When the neighbor AP information reported by the first AP contains a foreign AP identifier not managed by the first AC, the type of the first AP is determined to be the border AP.

[0037] When each AP identifier in the neighbor AP information reported by the first AP belongs to the APs managed by the first AC, or when the neighbor AP information reported by the first AP contains a foreign AP identifier not belonging to the first AC and no response information is received within a second preset time length, the type of the first AP is determined to be the inland AP.

[0038] In some embodiments, if the at least one neighbor AC corresponding to the first AC is determined by learning the roaming track, the type of each first AP is determined in the process of determining the at least one neighbor AC corresponding to the first AC, comprising:

[0039] After the roaming query request is broadcasted in the roaming domain VLAN, if the response information sent by the third AC is received within a second preset time length, the type of the access AP is determined to be the border AP; and

[0040] If no response information is received within the second preset time length, the type of the access AP is determined to be the inland AP.

[0041] In some embodiments, the method further comprises:

[0042] In response to the number of ACs included in the roaming domain VLAN being greater than a first preset threshold, the roaming query request is sent to each of the at least one neighbor AC, the neighbor AC being determined by exchanging foreign AP information and roaming track learning.

[0043] In some embodiments, the sending of the roaming query request to each of the at least one neighbor AC comprises:

[0044] In response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the configured sending mode being sending the request to the neighbor AC, the roaming query request is sent to each of the at least one neighbor AC, the neighbor AC being determined by roaming track learning.

[0045] In some embodiments, the method further comprises:

[0046] In response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the configured sending mode being roaming domain broadcast request, the roaming query request is broadcasted in the roaming domain VLAN; and

[0047] If the response information sent by the fourth AC is received, the first STA is caused to roam between the first AC and the fourth AC.

[0048] In some embodiments, the receiving of the response information sent by the target neighbor AC comprises:

[0049] The response information sent by the target neighbor AC is received through a tunnel between the first AC and the target neighbor AC.

[0050] In some embodiments, the causing of the first STA to roam between the first AC and the target neighbor AC comprises:

[0051] The first AC establishes an association with the first STA according to the response information, and the first STA is caused to roam between the first AC and the target neighbor AC.

[0052] In a second aspect, the application provides a wireless terminal roaming device, the device being arranged in a first access controller (AC), the device comprising:

[0053] a sending module configured to, in response to a first wireless terminal (STA) accessing any wireless access point (AP) managed by the first AC, send a roaming query request to each of at least one neighbor AC if it is determined that the first STA is not associated with the first AC, the at least one neighbor AC being an AC whose signal coverage range is adjacent to that of the first AC; and

[0054] The roaming module is configured to, if receiving the response information sent by the target neighbor AC, make the first STA roam between the first AC and the target neighbor AC.

[0055] In a third aspect, the present application provides an access controller, comprising: a processor and a memory connected with the processor in communication;

[0056] The memory stores computer-executable instructions.

[0057] The processor executes the computer-executable instructions stored in the memory to implement the wireless terminal roaming method according to any one of the first aspect.

[0058] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by a processor to implement the wireless terminal roaming method according to any one of the first aspect.

[0059] In a fifth aspect, the present application provides a computer program product, comprising a computer program, and the computer program is executed by a processor to implement the wireless terminal roaming method according to any one of the first aspect.

[0060] The wireless terminal roaming method, device, access controller, medium and program product provided by the present application, in the case that the first STA accesses any AP managed by the first AC, if it is determined that the first AC is not associated with the first STA, it indicates that the first STA has not connected to the wireless network through the first AC before. In this case, at least one neighbor AC corresponding to the first AC can be obtained, so that a roaming query request is sent to the at least one neighbor AC. If response information sent by any AC in the at least one neighbor AC is received, the first STA is made to roam between the first AC and the target neighbor AC sending the response information. The definition of the neighbor AC is an AC whose signal coverage range is adjacent to that of the first AC. In this way, the number of invalid query requests is reduced, thereby reducing the total data transmission amount, reducing the bandwidth usage, and further reducing the overall load of the network. On this basis, compared with the scheme of specifying an AC as a total controller, the present application avoids the dependence on a single total controller through a distributed query mechanism, thereby reducing the requirement for device performance and cost. On this basis, compared with the scheme that each AC in the roaming group synchronizes its own terminal list with each other, the present application sends a roaming query request to the neighbor AC only when needed, rather than synchronizing all terminal lists, thereby reducing the storage pressure of the AC. BRIEF DESCRIPTION OF DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the conventional technology description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort. The drawings herein are incorporated into the specification and form part of the specification, show the embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application.

[0062] FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0063] FIG. 2 is a flow diagram of a process for determining at least one neighbor AC corresponding to a first AC by exchanging foreign AP information according to an embodiment of the present application;

[0064] FIG. 3 is a flow diagram of a process for determining at least one neighbor AC corresponding to a first AC by learning a roaming track according to an embodiment of the present application;

[0065] FIG. 4 is a schematic diagram of an AC "jurisdiction" according to an embodiment of the present application;

[0066] FIG. 5 is a schematic diagram of another AC "jurisdiction" according to an embodiment of the present application;

[0067] FIG. 6 is a flow diagram of a wireless terminal roaming method according to an embodiment of the present application;

[0068] FIG. 7 is a schematic diagram of a wireless terminal roaming scenario according to an embodiment of the present application;

[0069] FIG. 8 is a schematic diagram of a wireless terminal roaming apparatus according to an embodiment of the present application;

[0070] FIG. 9 is a schematic diagram of an access controller according to an embodiment of the present application.

[0071] The above drawings have shown the specific embodiments of the present application, and the following will have a more detailed description. These drawings and the written description are not intended to limit the scope of the present application concept by any means, but to illustrate the present application concept to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0072] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The following description is made with reference to the accompanying drawings in which like reference numerals refer to like elements, and the term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Unless specifically stated otherwise, it is appreciated that, throughout this specification, functions, steps, or actions described can be performed in an order different from the order in which they are described. For example, functions, steps, or actions can be performed in an order different from the order in which they are described. Further, some or all functions, steps, or actions can be performed simultaneously, rather than sequentially as described. The description can refer to elements of a figure by reference number only. While certain figures can be used to describe the exemplary embodiments, the spirit of the exemplary embodiments is not limited to the specific configurations illustrated in these figures.

[0073] The terms "first", "second", and the like, do not denote any order, quantity, combination, or importance, but are used to identify one element from another. In the description of the following embodiments, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0074] In the thin AP architecture, the AP and the AC usually communicate through a tunneling protocol. The AP transmits the received wireless data to the AC through a tunnel for processing. For example, the tunneling protocol is the Control And Provisioning of Wireless Access Points Protocol Specification (CAPWAP) protocol.

[0075] The STA roams among the thin APs, and is divided into intra-AC roaming and inter-AC roaming. In the intra-AC roaming, a single AC controls the entire roaming process. In the inter-AC roaming, the roaming involves interaction between ACs. The roaming-in AC and the roaming-out AC need to establish a tunnel to exchange the roaming entry information of the STA, so that the STA can realize fast roaming. As known to those skilled in the art, the roaming entry information of the STA received by the roaming-in AC includes the Service Set identifier (SSID), the Pairwise Master Key Identifier (PMKID), the authentication mode, the security authentication mode, the roaming VLAN, and the like. The roaming-in AC can make the STA online without authentication through the roaming entry information of the STA, thereby improving the roaming efficiency. If the roaming-in AC cannot obtain the roaming entry information of the STA, the STA needs to perform association and authentication operations with the roaming-in AP, which consumes a long time. In the scenario of a large number of distributed ACs, there are more inter-AC roaming requirements between regions.

[0076] In the related art, a roaming group is configured, and a plurality of ACs are added to the same roaming group, indicating that STAs can roam between the ACs. When an STA accesses an AP, the AC to which the AP belongs, i.e., an in-roaming AC, sends a query request to each AC in the same roaming group. After receiving the query request, each AC in the same roaming group determines whether the STA is in the terminal list of the AC. If the STA is in the terminal list of the AC, the AC responds to the query request, interacts with the in-roaming AC, and sends an answer message to the in-roaming AC, and sends the roaming table information of the STA to the in-roaming AC. The answer message includes the roaming table information of the STA. This method has a defect. The in-roaming AC needs to send a query request to each AC in the same roaming group, but only one AC, i.e., an out-roaming AC, responds, so there are many invalid requests.

[0077] To address the above defect, in the related art, one AC in the same roaming group is designated as a master controller, and the master controller stores the terminal lists of the ACs in the roaming group. When an STA accesses an AP, the in-roaming AC sends a query request to the master controller. The master controller determines which AC the STA belongs to according to the stored terminal lists of the ACs, and sends the roaming table information of the STA to the in-roaming AC, so that the STA can roam between two ACs. This method has a high performance requirement for the master controller, and a higher model than other ACs may be required, resulting in a higher cost. Another method in the related art is that the ACs in the roaming group synchronize their respective terminal lists with each other. Each AC stores the terminal lists of the other ACs in the roaming group. When an STA accesses an AP, the in-roaming AC determines which AC the STA belongs to and finds the information of the STA. In this method, each AC needs to store the terminal lists of the other ACs in the same roaming group, increasing the storage pressure of the AC. In addition, because each AC needs to synchronize its respective terminal list, the real-time performance is poor.

[0078] For the two ACs that can achieve roaming between the ACs, the signal coverage ranges thereof are adjacent. The signal coverage range refers to the sum of the signal coverage ranges of the APs managed by the ACs. When an STA accesses an AP, the in-roaming AC is the AC to which the accessed AP belongs, and the out-roaming AC is likely to be an AC whose signal coverage range is adjacent to that of the in-roaming AC. It can be seen that the in-roaming AC only needs to send a roaming query request to a few ACs adjacent thereto, and does not need to send a roaming query request to each AC in the roaming group.

[0079] The application provides a roaming scheme of a wireless terminal. In the case that a first STA accesses any AP managed by a first AC, if it is determined that the first AC is not associated with the first STA, it indicates that the first STA has not connected to a wireless network through the first AC before. In this case, the first AC can only send a roaming query request to at least one neighbor AC, and if response information sent by any AC of the at least one neighbor AC is received, roaming table item information of the first STA sent by a target neighbor AC sending the response information is received through a tunnel, and roaming of the first STA between ACs is realized. The definition of the neighbor AC is that the signal coverage range of the AC is adjacent to the signal coverage range of the first AC, so that the number of invalid query requests is reduced, the total data transmission amount is reduced, the bandwidth usage is reduced, and the overall load of the network is reduced. Compared with the scheme in which one AC is specified as a total controller, the scheme of the embodiment of the application avoids the dependence on a single total controller, so that the requirement for the performance of the device and the cost are reduced. Compared with the scheme in which the terminal lists of the ACs in the roaming group are synchronized with each other, the roaming query request is sent to the neighbor AC only when needed in the application, instead of synchronizing all the terminal lists, so that the storage pressure of the AC is reduced.

[0080] FIG. 1 is a schematic diagram of an application scenario provided by the application. As shown in FIG. 1, the application scenario is a kind of wireless local area network architecture, including multiple ACs: AC10, AC11 and AC12.

[0081] Taking AC10 as an example, the AC10 is used for centralized management and control of multiple APs 20, and the AP 20 is used for direct wireless communication with the STA 30.

[0082] Among them, the multiple ACs belong to the same roaming domain virtual local area network (English: Virtual Local Area Network, abbreviated as VLAN). When deploying the wireless local area network architecture, a VLAN can be divided from a physical local area network, the VLAN is regarded as a roaming domain VLAN (RD-VLAN), and the roaming domain VLAN is respectively configured on each AC, so that the multiple ACs are located in the same roaming domain VLAN. It should be noted that the roaming domain VLAN can be divided by a technician according to actual business requirements, and the application does not limit this.

[0083] Since the multiple ACs belong to the same roaming domain VLAN, for any AC in the roaming domain VLAN, the AC can broadcast a message in the roaming domain VLAN, and each AC in the roaming domain VLAN can receive the message, and the AC can also receive the broadcast message of other ACs in the roaming domain VLAN, and sends response information to the AC broadcasting the broadcast message for the received message.

[0084] It can be seen that the scheme in the prior art needs the technician to configure all the ACs in the same group to join the roaming group on each AC in the roaming group in advance, for example, if there are 10 ACs in the roaming group, the technician needs to configure all the other 9 ACs to join the roaming group on each AC, and the configuration operation is complicated, while the present application only needs the technician to configure the same roaming domain VLAN on each AC, so that there is only one configuration operation for an AC, and there is no need to configure all the other ACs in the roaming group to join the roaming group on each AC, thereby simplifying the user configuration operation.

[0085] In an application scenario, when the STA 30 accesses any AP 20 in the wireless local area network architecture, the AP 20 uploads the related information of the STA 30 to the AC to which the AP 20 belongs, and the AC performs the wireless terminal roaming method provided by the present application to realize the roaming of the wireless terminal STA 30.

[0086] It should be noted that the number of the plurality of ACs can be set according to actual needs, and the present application does not limit this. For ease of representation, three examples are shown in FIG. 1.

[0087] The wireless terminal roaming method provided by the present application can be applied in network use scenarios such as enterprise office, campus, public environment (such as airport, shopping mall, hotel, etc.), and the present application does not limit this.

[0088] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0089] The execution subject of the wireless terminal roaming method provided by the present application is a wireless terminal roaming device, which is integrated in an AC. As described in the above application scenario, the roaming domain VLAN includes a plurality of ACs, and the following describes a first AC in the roaming domain VLAN as an example, and the implementation of the wireless terminal roaming method by each AC in the roaming domain VLAN is the same as that by the first AC.

[0090] In the present application, the first AC determines at least one neighbor AC of the first AC within a period of time after the first AC is powered on. In an optional embodiment, the implementation of determining at least one neighbor AC corresponding to the first AC includes: determining at least one neighbor AC corresponding to the first AC by exchanging foreign AP information within a first preset time period after the first AC is powered on; and / or determining at least one neighbor AC corresponding to the first AC by roaming trajectory learning within a first preset time period after the first AC is powered on.

[0091] The power-on refers to power-on start. The first preset time length can be set according to actual requirements, and the application does not make any limitation, for example, the first preset time length is 5 days, 7 days, 10 days, etc.

[0092] The process that the first AC determines at least one neighbor AC can be regarded as that the first AC is in a learning period, and the length of the learning period is the first preset time length. Optionally, the first AC enters the learning period immediately after power-on, and the triggering manner includes that the first AC automatically enters the learning period after power-on, or the first AC is manually triggered to enter the learning period after power-on. The manual triggering of the first AC to enter the learning period is specifically implemented as that the first AC is manually controlled to enter the learning period on a remote control interface of the first AC, or the first AC is manually configured to enter the learning period.

[0093] By introducing the concept of the learning period, the first AC can dynamically identify the neighbor ACs in the roaming domain VLAN, and the dynamic learning mechanism can more flexibly adapt to the change of the network topology, and improve the adaptability and expansibility.

[0094] The optional embodiment above reduces the demand for manual configuration by automatically identifying the neighbor ACs, reduces the workload of the technical personnel, and improves the efficiency of network deployment and maintenance.

[0095] The following will be described respectively for the exchange of foreign AP information and the roaming trajectory learning manner.

[0096] FIG. 2 is a flowchart of a process of determining at least one neighbor AC corresponding to the first AC by exchanging foreign AP information according to an embodiment of the application. As shown in FIG. 2, the process of determining at least one neighbor AC corresponding to the first AC by exchanging foreign AP information within the first preset time length after the first AC is powered on includes the following operations performed within the first preset time length after the first AC is powered on until the first preset time length is reached, which includes steps S101-S103.

[0097] In step S101, neighbor AP information reported by any first AP managed by the first AC is acquired, and the neighbor AP information includes AP identifiers respectively corresponding to each neighbor AP identified by the first AP.

[0098] The first AC is used to centrally manage and control a plurality of first APs. After the first AC is powered on, the first AC respectively issues an acquisition instruction to each first AP managed by the first AC, so that each first AP respectively acquires corresponding neighbor AP information and reports the acquired neighbor AP information to the first AC.

[0099] The neighbor AP of the first AP is an AP located around the first AP. The AP identifier is used to uniquely identify the AP, so as to distinguish different APs. For example, the AP identifier is a basic service set identifier (BSSID). Optionally, the implementation of the first AP obtaining the neighbor AP information includes: periodic spectrum scanning, smart radio (AI Radio) scanning, or Radio Resource Measurement of Wireless LANs (RRM) protocol scanning, for example, the RRM protocol is a function defined in the 802.11k protocol.

[0100] In step S102, if the foreign AP identifier not belonging to the first AC is contained in the neighbor AP information, the foreign AP identifier is added to the foreign AP list, and the foreign AP list is periodically broadcasted in the roaming domain VLAN.

[0101] In the embodiment of the present application, after the first AC obtains the neighbor AP information reported by any first AP, it is determined whether the neighbor AP information contains a foreign AP identifier not belonging to the first AC. Optionally, the first AC stores an internal AP list containing AP identifiers of APs belonging to the first AC. Accordingly, the determination of whether the neighbor AP information contains a foreign AP identifier not belonging to the first AC is specifically implemented as follows: for each AP identifier in the neighbor AP information, it is queried from the internal AP list whether the AP identifier is contained in the internal AP list. If the AP identifier is contained in the internal AP list, the AP indicated by the AP identifier belongs to the first AC. Conversely, if the AP identifier is not contained in the internal AP list, the AP indicated by the AP identifier does not belong to the first AC, and the AP identifier can be considered as a foreign AP identifier.

[0102] If the neighbor AP information contains a foreign AP identifier not belonging to the first AC, it means that the AP indicated by the foreign AP identifier is very likely to belong to an AC adjacent to the first AC. In this case, the foreign AP identifier can be added to the foreign AP list, and the foreign AP list can be periodically broadcasted in the roaming domain VLAN, so that other ACs in the roaming domain VLAN can receive the foreign AP list broadcasted by the first AC.

[0103] Optionally, the frequency of periodically broadcasting the foreign AP list can be set according to actual needs, which is not limited in the present application. For example, the frequency is 2 minutes, 5 minutes, or 10 minutes.

[0104] The first AC can also broadcast the list of foreign APs in a roaming domain VLAN in a non-periodic manner, as known to those skilled in the art. For example, when the number of foreign APs reaches a certain threshold, the first AC broadcasts the list of foreign APs.

[0105] In step S103, if the response information sent by the second AC for the list of foreign APs is received, the second AC is determined as a neighbor AC. The response information is sent by the second AC to the first AC when it is determined that the list of foreign APs contains the identifier of the AP belonging to the second AC.

[0106] In the embodiments of the present application, the ACs other than the first AC in the roaming domain VLAN determine whether the list of foreign APs contains the identifier of the AP belonging to the local AC after receiving the list of foreign APs broadcast by the first AC. Alternatively, taking the second AC as an example, the second AC stores an internal AP list containing the AP identifiers of the APs belonging to the second AC. Accordingly, the determination of whether the list of foreign APs contains the identifier of the AP belonging to the second AC is specifically implemented as follows: for each foreign AP identifier in the list of foreign APs, it is queried from the internal AP list whether the foreign AP identifier is contained in the internal AP list. If the foreign AP identifier is contained in the internal AP list, the AP indicated by the foreign AP identifier belongs to the second AC. Otherwise, if the foreign AP identifier is not contained in the internal AP list, the AP indicated by the foreign AP identifier does not belong to the second AC.

[0107] When the list of foreign APs contains the identifier of the AP belonging to the second AC, the second AC sends response information to the first AC to "claim" the foreign AP. The response information includes the AC identifier corresponding to the second AC and the AP identifier corresponding to the AP belonging to the second AC in the list of foreign APs.

[0108] Alternatively, the determination of the second AC as a neighbor AC is specifically implemented as follows: the AC identifier corresponding to the second AC is added to a neighbor AC list, and the neighbor AC list includes the AC identifier corresponding to each neighbor AC determined by the first AC. The AC identifier is used to uniquely identify the AC to distinguish different ACs. For example, the AC identifier is the Internet Protocol (IP) address or network identifier of the AC, such as the Media Access Control (MAC) address.

[0109] Optionally, after determining the second AC as a neighbor AC, the first AC further establishes a tunnel with the second AC, so as to implement inter-AC roaming by subsequent communication through the tunnel. Exemplarily, the tunnel is a Multicast Tunnel Interface (MTI) tunnel.

[0110] For any first AP managed by the first AC, if the signal coverage range of the first AP has an overlapping area with the signal coverage range of a neighbor AP, and the neighbor AP does not belong to the first AC, it is indicated that the neighbor AP is very likely to belong to an AC adjacent to the first AC, and the signal coverage range of the AC has an overlapping area with the signal coverage range of the first AC. Therefore, the AC can be regarded as an AC adjacent to the first AC in terms of signal coverage range, i.e., a neighbor AC of the first AC.

[0111] The embodiment of the present application determines the neighbor AC by exchanging foreign AP information, and automatically acquires and processes the neighbor AP information reported by the first AP by using the neighbor discovery capability of the AP, so that the first AC can establish the neighbor relationship between ACs in a short time.

[0112] Optionally, the first AC can not only enter the learning period immediately after being powered on to determine the neighbor AC, but also can re-enter the learning period after the learning period to determine new neighbor ACs once a new AC is added to the roaming domain VLAN. The trigger mode of re-entering the learning period includes that the first AC automatically enters the learning period in response to the addition of the new AC to the roaming domain VLAN, or the first AC is manually triggered to enter the learning period in the case of adding the new AC to the roaming domain VLAN. The manual triggering of the first AC to enter the learning period is specifically implemented as manually controlling the first AC to enter the learning period on the remote control interface of the first AC, or manually configuring the first AC to enter the learning period on the first AC.

[0113] The process of determining the addition of the new AC to the roaming domain VLAN includes that the ACs in the roaming domain VLAN are powered on and enter the learning period at the same time, periodically broadcast the foreign AP list in the learning period, and the ACs no longer broadcast the foreign AP list after the learning period, at which time it is considered that the neighbor ACs of the ACs are confirmed to be complete. After the learning period, if the AC receives the foreign AP list broadcast by any AC, it is considered that the AC is a newly added AC in the roaming domain VLAN, and the AC is in the learning period.

[0114] By re-entering the learning period when a new AC is added to the roaming domain VLAN, the ACs in the roaming domain VLAN can update the previously determined neighbor ACs, so that the determined neighbor ACs are more accurate.

[0115] FIG. 3 is a flowchart of a method for determining at least one neighbor AC corresponding to a first AC according to a roaming track learning manner, according to an embodiment of the present application. As shown in FIG. 3, the process of determining at least one neighbor AC corresponding to the first AC according to the roaming track learning manner within a first preset time period after the first AC is powered on includes the following operations performed within the first preset time period after the first AC is powered on until the first preset time period is reached: steps S201-S202.

[0116] In step S201, in response to the second STA accessing any first AP managed by the first AC, if it is determined that the second STA is not associated with the first AC, a roaming query request is broadcasted in the roaming domain VLAN.

[0117] In the above step S201, the second STA accesses the first AP, and the first AP reports STA information of the second STA to the first AC, and the STA information includes a STA identifier. The STA identifier can be a MAC address.

[0118] In a wireless network, the association between a STA and an AC means that the STA is connected to the network through an AP, and the access process and subsequent communication process of the STA are managed and controlled by the AC. When the STA accesses an AP for the first time, the AP reports STA information of the STA to the AC to which the AP belongs, and the AC records the STA in a terminal list, indicating that the STA is currently managed by the AC.

[0119] Optionally, the first AC stores a terminal list including STA identifiers corresponding to STAs associated with the first AC. Accordingly, determining whether the second STA is associated with the first AC is specifically implemented by determining whether the terminal list includes the STA identifier corresponding to the second STA. If the terminal list includes the STA identifier corresponding to the second STA, it indicates that the second STA is associated with the first AC. Otherwise, if the terminal list does not include the STA identifier corresponding to the second STA, it indicates that the second STA is not associated with the first AC. As known by those skilled in the art, when the second STA is associated with the first AC, the roaming table item information of the second STA is saved in the first AC, so as to realize fast intra-AC roaming and inter-AC roaming.

[0120] If it is determined that the second STA is not associated with the first AC, it indicates that the second STA accesses the first AC for the first time, and the second STA can be associated with other ACs in the roaming domain VLAN or can not be associated with any AC in the roaming domain VLAN. In this case, the first AC broadcasts a roaming query request in the roaming domain VLAN, and all other ACs in the roaming domain VLAN can receive the roaming query request. Compared with the prior art of sending a roaming query request to each of the other ACs in the roaming group, the method of broadcasting a roaming query request only needs to send the roaming query request once by the first AC, reduces the number of request sending times, thereby reducing the total data transmission amount, reducing the bandwidth usage, and further reducing the network load. The roaming query request carries a STA identifier corresponding to the second STA.

[0121] It should be noted that if it is determined that the second STA is associated with the first AC, it indicates that the second STA has accessed the first AC before, and then the AC-in roaming processing is directly performed.

[0122] In step S202, if the response information sent by the third AC for the roaming query request is received, it is determined that the third AC is a neighbor AC.

[0123] In the embodiment of the present application, after receiving the roaming query request broadcasted by the first AC, the ACs other than the first AC in the roaming domain VLAN determine whether the second STA is associated with the local AC. If the second STA is associated with the local AC, the response information is sent to the first AC to "claim" the second STA. The response information includes the AC identifier corresponding to the local AC and the STA identifier corresponding to the second STA. Alternatively, taking the third AC as an example, the third AC stores a terminal list containing the STA identifiers corresponding to the STAs associated with the third AC. Correspondingly, if the third AC determines that the STA identifier corresponding to the second STA is included in the terminal list, it indicates that the second STA is associated with the third AC, and the response information is sent to the first AC. Otherwise, if the third AC determines that the STA identifier corresponding to the second STA is not included in the terminal list, it indicates that the second STA is not associated with the third AC, and the roaming query request is ignored, that is, no response is made to the roaming query request.

[0124] Alternatively, the third AC is determined to be a neighbor AC, which is specifically implemented by adding the AC identifier corresponding to the third AC to a neighbor AC list. The neighbor AC list includes the AC identifier corresponding to each neighbor AC determined by the first AC.

[0125] Optionally, after determining the third AC as the neighbor AC, the first AC further establishes a tunnel with the third AC, so as to subsequently communicate through the tunnel, exchange the roaming table item information of the STA, and realize roaming of the STA between the ACs. Exemplarily, the tunnel is an MTI tunnel. As known by those skilled in the art, realizing roaming between the ACs means that the roaming table item information of the STA is obtained through tunnel communication, and fast roaming of the STA between the ACs is realized.

[0126] The embodiment of the present application realizes determination of the neighbor AC in the manner of roaming track learning. Only when the STA actually roams between the ACs, it can be perceived that the signal coverage ranges of the two ACs are adjacent. Therefore, when the second STA accesses, the third AC responding to the roaming query request is determined as the neighbor AC of the first AC through broadcasting the roaming query request, and the accuracy is high.

[0127] The above step S202 is described for the case of receiving the response information. Correspondingly, the method provided by the embodiment of the present application further includes: if the response information sent by the third AC in response to the roaming query request is received within a second preset time length, the roaming table item information of the STA is exchanged between the first AC and the third AC through the corresponding tunnel, and fast roaming of the STA between the first AC and the third AC is realized. The second preset time length can be set according to actual requirements, for example, the second preset time length is 50 milliseconds, 60 milliseconds, etc. The first AC is adjacent to the third AC. After receiving the response information, the first AC establishes a tunnel with the third AC, so as to realize roaming of the STA between the ACs through the tunnel, to make the STA fast roam to realize normal use of the wireless network, and avoid disconnection.

[0128] In the embodiment of the present application, there is also a case that no response information is received. If the response information is not received within the second preset time length, the second STA is associated according to the first association strategy.

[0129] If the response information is not received within the second preset time length, it is indicated that the second STA is not associated with any AC in the roaming domain VLAN. Therefore, it can be considered that the second STA accesses for the first time, and the second STA is associated with the first AC according to the first association strategy, so that the second STA can roam in the AC through the first AC. The first association strategy can refer to the technical means of the STA accessing for the first time and being associated with the AC in the related art, and details are not described herein. As known by those skilled in the art, when the second STA accesses for the first time and is associated with the first AC, the first AC will establish and save the roaming table item information of the second STA, to realize fast roaming in the AC and between the ACs.

[0130] On the basis of the embodiment shown in Fig. 3, the embodiment of the present application further provides two supplementary schemes. One scheme is that if the reply information is received within the second preset time length, the first AC can interact with the third AC through a tunnel to exchange the roaming table information of the second STA, so as to realize the fast roaming of the second STA, ensure the seamless transfer of the session information and state of the second STA, and improve the reliability and efficiency of roaming. Another scheme is that if the reply information is not received within the second preset time length, the first AC can be associated with the second STA according to the first association strategy. This flexible strategy ensures the effective roaming of the second STA and guarantees the continuity of network service.

[0131] Generally, the APs managed by an AC have regional characteristics, i.e., the APs managed by each AC are physically aggregated. The sum of the signal coverage ranges of the APs managed by each AC can be referred to as the "jurisdiction" of the AC, which can be regarded as the signal coverage range of the AC.

[0132] There are two cases of inter-AC roaming. One case is that the "jurisdictions" of two ACs have overlapping regions, and the STA can move through the overlapping region. Referring to the AC "jurisdiction" schematic diagram shown in Fig. 4, the "jurisdiction" of AC 10 has an overlapping region with the "jurisdiction" of AC 11, so that the STA can have inter-AC roaming between AC 10 and AC 11; the "jurisdiction" of AC 11 has an overlapping region with the "jurisdiction" of AC 12, so that the STA can have inter-AC roaming between AC 11 and AC 12; and the "jurisdiction" of AC 10 has no overlapping region with the "jurisdiction" of AC 12, so that the STA cannot have inter-AC roaming between AC 10 and AC 12. Those skilled in the art can know that for the case that the "jurisdictions" of two ACs have overlapping regions, the neighbor ACs with overlapping "jurisdictions" can be determined through the neighbor list of the APs in the learning period of the AC, as shown in Fig. 2; or the neighbor ACs can be determined through the VLAN query in the roaming domain, as shown in Fig. 3.

[0133] Another case is that there is no overlapping area between the "jurisdiction" of two ACs, and there is a signal blind area in between, but the STA 30 loses signal for a time that does not exceed the anti-shake time when crossing the signal blind area, so that the STA 30 is not timed out to be offline, and can be connected through inter-AC roaming. Referring to the AC "jurisdiction" diagram shown in FIG. 5, there is no overlapping area between the "jurisdiction" of the AC 13 and the "jurisdiction" of the AC 14, but when the STA 30 crosses from the "jurisdiction" of the AC 13 to the "jurisdiction" of the AC 14, the STA 30 can cross the signal blind area within the anti-shake time, so that inter-AC roaming can occur between the AC 13 and the AC 14. Wherein, for the definition of the anti-shake time, when the STA 30 leaves the signal coverage range of the AC 13, the AC 13 will maintain the online state of the STA 30 for a period of time, and if the STA 30 is online again within this period of time, it is not considered that the STA 30 is offline and then online, but it is considered that the STA 30 is always online, and this period of time is called the anti-shake time, and the anti-shake time can be set according to actual needs, for example, 2 minutes, 5 minutes, etc. Those skilled in the art can know that for the case that there is no overlapping area between the "jurisdiction" of two ACs but the signal loss time does not exceed the anti-shake time, the method shown in FIG. 3 can be used to determine the neighbor ACs that do not have overlapping areas with the "jurisdiction" of the first AC but have signal loss time that does not exceed the anti-shake time within the learning period of the AC through the roaming domain VLAN query.

[0134] It can be seen that the neighbor ACs are determined by exchanging foreign AP information, the information of surrounding APs is quickly collected by using the neighbor discovery capability of the AP, so that the neighbor relationship between the ACs can be established within a short time, and the determined neighbor ACs are the ACs that have overlapping areas with the signal coverage range of the first AC, but this method cannot determine the neighbor ACs that do not have overlapping areas with the signal coverage range of the first AC but have a signal blind area that is not enough to make the STA offline, and the roaming trajectory learning method can determine the neighbor ACs in the above two cases, but the neighbor ACs can be determined only when the STA is accessed. Therefore, the neighbor ACs determined by simultaneously using the exchange foreign AP information method and the roaming trajectory learning method are more comprehensive.

[0135] On the basis of the embodiments shown in FIGS. 2 and 3, in an optional embodiment, the type of each first AP managed by the first AC can also be determined in the process of determining the neighbor ACs, and accordingly, the wireless terminal roaming method provided by the present application further comprises:

[0136] In the process of determining the at least one neighbor AC corresponding to the first AC, the types of the first APs are determined, and the types of the first APs are written into the internal AP list; the type is a border AP or an inland AP, and the neighbor APs of the inland AP all belong to the first AC, and at least one of the neighbor APs of the border AP does not belong to the first AC.

[0137] If the type of any first AP is a border AP, a mapping relationship between the first AP and a corresponding neighbor AC is stored; the corresponding neighbor AC refers to a neighbor AP of the first AP that does not belong to the AC to which the neighbor AP of the first AP belongs.

[0138] Optionally, the storing of the mapping relationship between the first AP and the corresponding neighbor AC is specifically implemented as follows: the mapping relationship between the first AP and the corresponding neighbor AC is added to an internal AP list; or the mapping relationship between the first AP and the corresponding neighbor AC is stored in a border AP mapping relationship table. The border AP mapping relationship table stores the mapping relationship between each border AP and a corresponding neighbor AC.

[0139] By writing the type of the first AP into the internal AP list, the first AC can update and manage the AP information in real time. In addition, by distinguishing the border AP and the inland AP, the network administrator can more clearly understand the network topology structure. The border AP is located at the boundary of different ACs, while the inland AP is completely within the management range of the same AC. Such type distinction helps the visualization of the network topology, so that the network administrator can more intuitively understand the distribution and mutual relationship of the APs, facilitating network planning and optimization.

[0140] In an optional implementation, if at least one neighbor AC corresponding to the first AC is determined through the exchange of foreign AP information, the implementation of determining the type of each first AP in the process of determining the at least one neighbor AC corresponding to the first AC includes: in a case where the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC, determining that the type of the first AP is a border AP; in a case where each AP identifier in the neighbor AP information reported by the first AP belongs to the first AC, or in a case where the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC and no response information is received within a second preset time length, determining that the type of the first AP is an inland AP.

[0141] If the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC, and the first AC receives response information within the second preset time length, it indicates that the foreign AP indicated by the foreign AP identifier belongs to a neighbor AC of the first AC, and the signal coverage range of the first AP and the signal coverage range of the foreign AP have an overlapping area. Correspondingly, the signal coverage range of the first AC and the signal coverage range of the neighbor AC have an overlapping area, so the first AP is located at the border of the first AC and the neighbor AC, and the type of the first AP is a border AP.

[0142] If all the AP identifiers in the neighbor AP information reported by the first AP belong to the first AC, it indicates that the signal coverage range of the first AP has no overlapping area with the signal coverage range of any foreign AP, and the first AP is not located at the boundary of the first AC and any neighbor AC, and thus the first AP can be considered as an inland AP.

[0143] If the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC, and the first AC does not receive the response information within the second preset time length, it indicates that no AC in the roaming domain VLAN claims the foreign AP indicated by the foreign AP identifier, which can be caused by the fact that the foreign AP belongs to another vendor or has not joined the roaming domain VLAN, and thus the first AP can be considered as an inland AP.

[0144] Exemplarily, the initial type of each first AP in the internal AP list is an unknown identity AP, if the first AP cannot scan a foreign AP, the type of the first AP is updated from the initial type to an inland AP; if the first AP can scan a foreign AP, and the foreign AP has been claimed by another AC, the type of the first AP is updated from the initial type to a boundary AP, and the mapping relationship between the first AP and the AC that claims the foreign AP is also written into the internal AP list; if the first AP can scan a foreign AP, but no AC claims the foreign AP within the learning period, the type of the first AP is updated from the initial type to an inland AP.

[0145] The embodiments of the present application can accurately identify boundary APs and inland APs by analyzing the neighbor AP information reported by the first AP.

[0146] In an optional implementation, if at least one neighbor AC corresponding to the first AC is determined by the roaming trajectory learning manner, the implementation of determining the type of each first AP in the process of determining the at least one neighbor AC corresponding to the first AC includes: after the roaming query request is broadcasted in the roaming domain VLAN, if the response information sent by the third AC for the roaming query request is received within the second preset time length, the type of the access AP is determined as a boundary AP; if no response information is received within the second preset time length, the type of the access AP is determined as an inland AP.

[0147] The second STA accesses any AP managed by the first AC, which can be regarded as an access AP.

[0148] If the response information sent by the third AC for the roaming query request is received within the second preset time length, it indicates that the third AC is a neighbor AC of the first AC, and the second STA can perform inter-AC roaming through the access AP, and thus the type of the access AP can be determined as a boundary AP.

[0149] If the response information is not received within the second preset time length, it is indicated that the second STA is not associated with any AC in the roaming domain VLAN, and the second STA performs inter-AC roaming through the access AP, and it is determined that the access AP is an inland AP. It should be noted that if other STAs access the access AP and perform inter-AC roaming through the access AP in the process of determining at least one neighbor AC corresponding to the first AC, the type of the access AP can also be updated to a border AP.

[0150] Embodiments of the present application distinguish between border APs and inland APs by analyzing whether response information is received for the roaming query request. This method is relatively simple and easy to implement.

[0151] In the embodiments of the present application, after determining at least one neighbor AC corresponding to the first AC, when the STA accesses any AP managed by the first AC, the first AC performs the wireless terminal roaming method provided by the present application to realize the roaming of the STA. FIG. 6 is a flowchart of a wireless terminal roaming method provided by an embodiment of the present application. As shown in FIG. 6, the method is applied to the first AC. The wireless terminal roaming method includes the following steps.

[0152] In step S301, in response to the first STA accessing any AP managed by the first AC, if it is determined that the first STA is not associated with the first AC, a roaming query request is sent to at least one neighbor AC. The neighbor AC is an AC whose signal coverage range is adjacent to the signal coverage range of the first AC.

[0153] In the embodiments of the present application, the first STA accesses the AP, and the AP reports the STA information of the first STA to the first AC. The STA information includes the STA identifier. Optionally, the first AC stores a terminal list containing the STA identifiers corresponding to each STA associated with the first AC. Correspondingly, determining whether the first STA is associated with the first AC is specifically implemented as follows: determining whether the terminal list contains the STA identifier corresponding to the first STA. If it contains, it indicates that the first STA is associated with the first AC. Otherwise, if it does not contain, it indicates that the first STA is not associated with the first AC.

[0154] If it is determined that the first STA is not associated with the first AC, it means that the first STA is accessing the first AC for the first time, and the first STA can have been associated with other ACs in the roaming domain VLAN or can not have been associated with any AC in the roaming domain VLAN. In this case, since the first AC has determined at least one neighbor AC, the first AC can send a roaming query request to the at least one neighbor AC respectively. Specifically, the first AC obtains an AC identifier corresponding to each of the at least one neighbor AC from the neighbor AC list. In one case, the first AC has established a tunnel with each of the neighbor ACs when determining the neighbor ACs, and accordingly, the first AC sends a roaming query request to each of the neighbor ACs through the tunnel to ensure that the roaming query request can be correctly routed to the neighbor AC. The roaming query request carries a STA identifier corresponding to the first STA. In another case, the first AC does not establish a tunnel when determining the neighbor ACs, and thus needs to establish a tunnel with each of the neighbor ACs before sending the roaming query request.

[0155] It should be noted that if it is determined that the first STA is associated with the first AC, it means that the first STA has accessed the first AC before, and then the AC-in roaming processing is directly performed.

[0156] Step S302, if the response information sent by the target neighbor AC to the roaming query request is received, the first STA is caused to roam between the first AC and the target neighbor AC.

[0157] The at least one neighbor AC respectively receives the roaming query request sent by the first AC, and after receiving the roaming query request sent by the first AC, determines whether the first STA is associated with the local AC. Optionally, taking any neighbor AC as an example, the neighbor AC stores a terminal list containing a STA identifier corresponding to each STA associated with the neighbor AC. Accordingly, determining whether the first STA is associated with the neighbor AC is specifically implemented by determining whether the terminal list contains a STA identifier corresponding to the first STA, if yes, it means that the first STA is associated with the neighbor AC; otherwise, if no, it means that the first STA is not associated with the neighbor AC.

[0158] For convenience of distinction, the neighbor AC associated with the first STA is referred to as a target neighbor AC, and the target neighbor AC sends response information to the roaming query request to the first AC in the case that the target neighbor AC determines that the first STA is associated with the target neighbor AC, so as to "claim" the first STA. The response information includes an AC identifier corresponding to the target neighbor AC and a STA identifier corresponding to the second STA.

[0159] After receiving the response information, the first AC causes the first STA to roam between the first AC and a target neighbor AC. As can be appreciated by one skilled in the art, the target neighbor AC can send the response message through a tunnel between the first AC and the target neighbor AC, and correspondingly, the first AC can receive the response message through the tunnel between the first AC and the target neighbor AC.

[0160] In the case where the first STA accesses any AP managed by the first AC, if it is determined that the first AC is not associated with the first STA, it indicates that the first STA has not connected to the wireless network through the first AC before. In this case, at least one neighbor AC corresponding to the first AC can be acquired, so that the roaming query request is sent to the at least one neighbor AC only, and if the response information sent by any AC of the at least one neighbor AC is received, the first STA is caused to roam between the first AC and the target neighbor AC sending the response information. The neighbor AC is defined as an AC whose signal coverage range is adjacent to that of the first AC, which reduces the number of invalid query requests, thereby reducing the total data transmission amount, reducing the bandwidth usage, and further reducing the network load. Compared with the scheme of specifying an AC as a total controller, the scheme in the embodiment of the present application avoids the dependence on a single total controller, thereby reducing the requirement for device performance and cost. Compared with the scheme of synchronizing the terminal list of each AC in the roaming group, the scheme in the embodiment of the present application sends the roaming query request to the neighbor AC only when needed, rather than synchronizing all terminal lists, thereby reducing the storage pressure of the AC.

[0161] The above step S302 is described for the case of receiving the response information. In the embodiment of the present application, there is also a case where no response information is received. Correspondingly, after sending the roaming query request to the at least one neighbor AC respectively, the method provided by the embodiment of the present application further includes: if the response information is not received within a second preset time length, associating with the first STA according to a first association strategy.

[0162] If the response information is not received within the second preset time length, it indicates that the first STA is not associated with any AC in the roaming domain VLAN, and therefore, it can be considered that the first STA is accessing for the first time, so that the first STA is associated with the first AC according to the first association strategy, so that the first STA can perform inter-AC roaming through the first AC. The first association strategy can refer to the technical means of the STA accessing and associating with the AC for the first time in the related art, which will not be described herein again.

[0163] In an alternative embodiment, the implementation of the step S301 of sending the roaming query request to each of the at least one neighbor AC comprises: if it is determined that the type of the access AP is a border AP, or it is determined that the type of the access AP is an inland AP and the first STA accesses the access AP using a re-association request frame, then the roaming query request is sent to each of all the neighbor ACs of the first AC.

[0164] The first AC stores an internal AP list, which includes each AP managed by the first AC, and further includes the type of each AP, which is either a border AP or an inland AP. Thus, the first AC can query the type of the access AP from the internal AP list.

[0165] The request frame used by the STA when accessing the AP can be an association request frame, or a re-association request frame.

[0166] In the first case, if it is an association request frame, it means that the STA considers that it is accessing the wireless network for the first time, and thus there is no need to send the roaming query request to the neighbor ACs. Correspondingly, the method provided by the embodiment of the present application further comprises: if it is determined that the type of the access AP is an inland AP and the STA accesses the access AP using an association request frame, then the first AC is associated with the STA according to a first-time association strategy.

[0167] In the second case, if it is a re-association request frame, it means that the STA considers that it has accessed the wireless network before and is accessing the wireless network again. Thus, the STA is very likely to have been associated with a certain AC in the roaming domain VLAN. Therefore, in the case that the type of the access AP is a border AP, or the type of the access AP is an inland AP but the STA uses a re-association request frame, the roaming query request can be sent to each of the neighbor ACs.

[0168] By sending the roaming query request to each of all the neighbor ACs, it is ensured that all possible cross-AC roaming paths are covered, and the reliability and success rate of roaming are improved.

[0169] In an alternative embodiment, the first AC further stores a mapping relationship between the APs of the border AP type and the corresponding neighbor ACs. If it is determined that the type of the access AP is a border AP, then the roaming query request can be further sent to each of the neighbor ACs having a mapping relationship with the access AP.

[0170] The first AC can query the neighbor ACs having a mapping relationship with the access AP from the internal AP list or the mapping relationship table of the border APs. By sending the roaming query request to each of the neighbor ACs having a mapping relationship with the access AP, the number of invalid query requests is further reduced, and the query efficiency is improved.

[0171] In the embodiments of the present application, the roaming track learning manner can determine both the neighbor ACs overlapping with the AC of the jurisdiction and the neighbor ACs not overlapping with the AC of the jurisdiction, and thus has high accuracy, but depends on the access of the STA, resulting in slow determination speed and long time consumption. The exchange foreign AP information manner does not depend on the access of the STA, and thus can quickly determine the neighbor ACs, but can only determine the neighbor ACs overlapping with the AC of the jurisdiction, and it is difficult to determine all the neighbor ACs, and thus has low accuracy. Considering that the number of ACs in the roaming domain VLAN can be large or small, the operation of sending the roaming query request to at least one neighbor AC in step S301 can also be performed according to the number of ACs, and specifically includes the following two cases.

[0172] In a first case, in response to the number of ACs included in the roaming domain VLAN being greater than a first preset threshold, the roaming query request is sent to at least one neighbor AC, which is determined by the exchange foreign AP information manner and the roaming track learning manner. The first preset threshold can be set as needed, for example, the first preset threshold is 4, 5, or 6, etc. The number of ACs included in the roaming domain VLAN being greater than the first preset threshold indicates that the number of ACs is large, and in this case, the exchange foreign AP information manner and the roaming track learning manner can be used together to determine the neighbor ACs, so that the neighbor ACs can be quickly determined, and all the neighbor ACs can be determined, and thus the accuracy is high.

[0173] In a second case, in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold, the roaming query request is sent to at least one neighbor AC, which is determined by the roaming track learning manner. The number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold indicates that the number of ACs is small, and in this case, the roaming track learning manner can be used to determine the neighbor ACs, and thus the accuracy is high, and the processing resources of the first AC can also be saved.

[0174] Optionally, in the case that the number of ACs included in the roaming domain VLAN is less than or equal to the first preset threshold, the first AC can also be configured to send the roaming query request in advance, which can be configured to send the request to the neighbor ACs, or can be configured to broadcast the request in the roaming domain.

[0175] In one case, in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the configured sending manner being sending the request to the neighbor ACs, the roaming query request is sent to at least one neighbor AC, which is determined by the exchange foreign AP information manner or the roaming track learning manner.

[0176] Another case is: in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the sending mode being the roaming domain broadcast request, the roaming query request is broadcasted in the roaming domain VLAN; if the response information sent by any one AC to the roaming query request is received, the STA is caused to roam between the first AC and the AC. In this embodiment, the first AC no longer needs to learn the neighbor AC, and does not need to maintain the information related to the neighbor AC, and the learning process in the early stage can be reduced.

[0177] In the embodiment of the present application, the first AC can dynamically adjust the strategy according to the network size, that is, according to the number of ACs included in the roaming domain VLAN, and the flexibility is relatively strong.

[0178] Referring to FIG. 1, the AC 10, the AC 11 and the AC 12 respectively determine at least one neighbor AC in the learning period, and if the STA 30 accesses any AP 20, the AC to which the AP 20 belongs broadcasts the roaming query request in the roaming domain VLAN.

[0179] Referring to the wireless terminal roaming scenario shown in FIG. 7, the AC 10 and the AC 11 have determined the neighbor relationship according to the roaming trajectory learning mode and established the MTI tunnel in the learning period, and the AC 11 and the AC 12 have determined the neighbor relationship according to the exchange of AP information and established the MTI tunnel in the learning period. Accordingly, if the STA 30 accesses the border AP 21 managed by the AC 11 in the learning period, the roaming query request is only sent to at least one neighbor AC respectively; and if the STA 31 accesses the inland AP 22 managed by the AC 12, the roaming mode is further selected according to the request frame used by the STA 30.

[0180] FIG. 8 is a structural schematic diagram of a wireless terminal roaming device provided by an embodiment of the present application. As shown in FIG. 8, the wireless terminal roaming device 40 can be arranged in the first AC, and the wireless terminal roaming device 40 includes: a sending module 401 configured to, in response to the first wireless terminal STA accessing any wireless access point AP managed by the first AC, send a roaming query request to at least one neighbor AC respectively if it is determined that the first STA is not associated with the first AC; the neighbor AC is an AC adjacent to the signal coverage range of the first AC; and a roaming module 402 configured to, if the response information sent by the target neighbor AC to the roaming query request is received, cause the first STA to roam between the first AC and the target neighbor AC.

[0181] In some embodiments, the sending module 401 is specifically configured to: if it is determined that the type of the accessed AP is a border AP, or it is determined that the type of the accessed AP is an inland AP and the first STA accesses the accessed AP by using the reassociation request frame, send the roaming query request to all neighbor ACs of the first AC respectively.

[0182] In some embodiments, the sending module 401 is specifically configured to: if it is determined that the type of the access AP is a border AP, send a roaming query request to each neighbor AC having a mapping relationship with the access AP respectively.

[0183] In some embodiments, if it is determined that the first STA is not associated with the first AC, the roaming module 402 is further configured to: if it is determined that the type of the access AP is an inland AP and the first STA accesses the access AP using an association request frame, associate with the first STA according to a first association strategy.

[0184] In some embodiments, the roaming module 402 is further configured to: after sending the roaming query request to the at least one neighbor AC respectively, if no response information is received within a second preset time period, associate with the first STA according to a first association strategy.

[0185] In some embodiments, the device further comprises a determining module configured to: determine the at least one neighbor AC corresponding to the first AC through an exchange of foreign AP information manner within a first preset time period after the first AC is powered on; and / or determine the at least one neighbor AC corresponding to the first AC through a roaming trajectory learning manner within the first preset time period after the first AC is powered on.

[0186] In some embodiments, the roaming domain virtual local area network (VLAN) comprises a plurality of ACs, and the plurality of ACs include the first AC. When the determining module determines the at least one neighbor AC corresponding to the first AC through the exchange of foreign AP information manner within the first preset time period after the first AC is powered on, the determining module is specifically configured to: perform the following operations within the first preset time period after the first AC is powered on until the first preset time period is reached, the operations comprising: obtaining neighbor AP information reported by any first AP managed by the first AC; the neighbor AP information comprising AP identifiers respectively corresponding to each neighbor AP identified by the first AP; in a case where the neighbor AP information contains a foreign AP identifier not belonging to the first AC, adding the foreign AP identifier to a foreign AP list and periodically broadcasting the foreign AP list within the roaming domain VLAN; if response information sent by a second AC for the foreign AP list is received, determining that the second AC is a neighbor AC; the response information being sent by the second AC to the first AC in a case where it is determined that the foreign AP list contains an AP identifier corresponding to the second AC.

[0187] In some embodiments, the roaming domain VLAN includes a plurality of ACs, and the plurality of ACs includes the first AC, and the determining module is configured to determine at least one neighbor AC corresponding to the first AC through the roaming track learning manner within a first preset time period after the first AC is powered on, and specifically configured to: perform the following operations within the first preset time period after the first AC is powered on until the first preset time period is reached, the operations including: in response to a second STA accessing any first AP managed by the first AC, if it is determined that the second STA is not associated with the first AC, broadcasting a roaming query request in the roaming domain VLAN; and if response information sent by a third AC for the roaming query request is received, determining that the third AC is a neighbor AC.

[0188] In some embodiments, the determining module is further configured to: if the response information sent by the third AC for the roaming query request is received within a second preset time period, roaming with the third AC through a corresponding tunnel; and if the response information is not received within the second preset time period, associating with the second STA according to a first association strategy.

[0189] In some embodiments, the determining module is further configured to: in the process of determining the at least one neighbor AC corresponding to the first AC, determining the type of each first AP, and writing the type of each first AP into an internal AP list; the type is a border AP or an inland AP, each neighbor AP of the inland AP belongs to the first AC, and at least one neighbor AP of the border AP does not belong to the first AC; and if the type of any first AP is the border AP, storing a mapping relationship between the first AP and a corresponding neighbor AC; the corresponding neighbor AC is an AC to which a neighbor AP not belonging to the first AC belongs.

[0190] In some embodiments, if the at least one neighbor AC corresponding to the first AC is determined through the exchanging foreign AP information manner, the determining module is specifically configured to: in a case where the neighbor AP information reported by the first AP includes a foreign AP identifier not belonging to the first AC, determining that the type of the first AP is a border AP; in a case where each AP identifier in the neighbor AP information reported by the first AP belongs to the first AC, or in a case where the neighbor AP information reported by the first AP includes a foreign AP identifier not belonging to the first AC and no response information is received within a second preset time period, determining that the type of the first AP is an inland AP.

[0191] In some embodiments, if the at least one neighbor AC corresponding to the first AC is determined through the roaming track learning manner, the determining module is specifically configured to: after the roaming query request is broadcasted in the roaming domain VLAN, if the response information sent by the third AC for the roaming query request is received within a second preset time period, determining that the type of the access AP is a border AP; and if the response information is not received within the second preset time period, determining that the type of the access AP is an inland AP.

[0192] In some embodiments, the sending module 401 is specifically configured to: in response to the number of ACs included in the roaming domain VLAN being greater than the first preset threshold, send the roaming query request to at least one neighbor AC respectively, the neighbor AC being determined through the exchange of foreign AP information and the roaming track learning.

[0193] In some embodiments, the sending module 401 is specifically configured to: in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the sending manner configured being sending the request to the neighbor AC, send the roaming query request to at least one neighbor AC respectively, the neighbor AC being determined through the roaming track learning.

[0194] In some embodiments, the roaming module 402 is further configured to: in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the sending manner configured being roaming domain broadcast request, broadcast the roaming query request in the roaming domain VLAN; and if receiving the response information sent by any one AC to the roaming query request, roaming with the AC through the corresponding tunnel.

[0195] The wireless terminal roaming apparatus 40 provided by the embodiments of the present application can execute the technical solutions of the corresponding method embodiments, and the implementation principles and technical effects thereof are similar to those of the corresponding method embodiments, which will not be described here again.

[0196] The embodiments of the present application further provide an access controller. FIG. 9 is a structural schematic diagram of an access controller provided by the embodiments of the present application. As shown in FIG. 9, the access controller 50 includes a processor 501 and a memory 502 in communication connection with the processor 501.

[0197] The memory 502 stores computer execution instructions; and the processor 501 executes the computer execution instructions stored in the memory 502 to implement the wireless terminal roaming method provided by the present application.

[0198] In the embodiments of the present application, the memory 502 and the processor 501 are connected through a bus. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus can be divided into an address bus, a data bus, a control bus, and the like. The components shown in the present text, their connections and relationships, and their functions are merely by way of example, and are not intended to limit the implementation of the present application described in the present text and / or claimed. The various components are connected to each other by different buses, and can be installed on a common mainboard or otherwise installed as needed.

[0199] In an example embodiment, a computer readable storage medium is also provided, and the computer readable storage medium stores computer execution instructions. When the computer execution instructions are executed by a processor, the computer execution instructions are used to implement the wireless terminal roaming method provided by the present application.

[0200] In an example embodiment, a computer program product is also provided, and the computer program product includes a computer program. When the computer program in the computer program product is executed by a processor, the computer program is used to implement the wireless terminal roaming method provided by the present application.

[0201] It should be noted that, for the foregoing method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0202] It should be further noted that, although the steps in the flowchart are shown in sequence according to the arrows, these steps are not necessarily executed in sequence according to the arrows. Unless explicitly stated in the present text, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, at least part of the steps in the flowchart can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these sub-steps or stages is not necessarily sequential, but can be executed in rotation or alternation with other steps or sub-steps or stages of other steps.

[0203] It should be understood that the above-mentioned device embodiments are only illustrative, and the device of the present application can also be implemented in other manners. For example, the division of units / modules in the above-mentioned embodiments is only a logical function division, and actual implementation can have another division manner. For example, multiple units / modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0204] In addition, each functional unit / module in each embodiment of the present application can be integrated in one unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated together. The integrated unit / module can be realized in the form of hardware or in the form of a software program module.

[0205] If implemented in hardware, the integrated units / modules can be digital circuitry, analog circuitry, or a combination of both. The physical implementation of the hardware structures includes, but is not limited to, transistors, memristors, etc. Unless otherwise specified, a processor can be any suitable hardware processor, such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic device. Unless otherwise specified, a memory can be implemented by any type of volatile or non-volatile storage devices or a combination thereof, such as a U disk, a random-access memory (RAM), a static random-access memory (SRAM), a dynamic random-access memory (DRAM), an enhanced dynamic random-access memory (EDRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a high-bandwidth memory (HBM), a hybrid memory cube (HMC), or various media that can store program codes.

[0206] The integrated units / modules, if implemented in the form of software program modules and sold or used as independent products, can be stored in a computer readable memory. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a memory, and includes a number of instructions to enable an access controller to perform all or part of the steps of the embodiments of the present application.

[0207] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments. The technical features of the above embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0208] Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The application is intended to cover any variations, uses or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains or can relate. The specification and examples are to be regarded as exemplary only, and the true scope and spirit of the application are indicated by the appended claims.

[0209] It should be understood that the application is not limited to the precise construction that has been described and illustrated herein and that various modifications and changes can be made therein without departing from the scope thereof. The scope of the application is indicated by the appended claims.

Claims

A wireless terminal roaming method, applied to a first access controller (AC), the method comprising: in response to a first wireless terminal (STA) accessing any wireless access point (AP) managed by the first AC, if it is determined that the first STA is not associated with the first AC, sending a roaming query request to at least one neighbor AC respectively; the at least one neighbor AC is an AC whose signal coverage range is adjacent to that of the first AC; and if the response information sent by a target neighbor AC is received, causing the first STA to roam between the first AC and the target neighbor AC. The sending of the roaming query request to the at least one neighbor AC respectively comprises: The method of claim 1, wherein, if it is determined that the type of the accessed AP is a border AP, or it is determined that the type of the accessed AP is an inland AP and the first STA accesses the accessed AP using a re-association request frame, sending the roaming query request to all neighbor ACs of the first AC respectively. The sending of the roaming query request to the at least one neighbor AC respectively comprises: The method of claim 1, wherein, if it is determined that the type of the accessed AP is a border AP, sending the roaming query request to each neighbor AC having a mapping relationship with the accessed AP respectively. The method of claim 1, further comprising: if it is determined that the type of the accessed AP is an inland AP and the first STA accesses the accessed AP using an association request frame, associating with the first STA according to a first association strategy. After the sending of the roaming query request to the at least one neighbor AC respectively, further comprising: The method of any one of claims 1-4, wherein if no response information is received within a second preset time period, associating with the first STA according to a first association strategy. Further comprising: The method of claim 1, wherein, determining the at least one neighbor AC corresponding to the first AC through an exchange of foreign AP information within a first preset time period after the first AC is powered on; and / or determining the at least one neighbor AC corresponding to the first AC through a roaming trajectory learning within a first preset time period after the first AC is powered on. The roaming domain virtual local area network (VLAN) comprises a plurality of ACs, and the plurality of ACs include the first AC, the determining of the at least one neighbor AC corresponding to the first AC through the exchange of foreign AP information within the first preset time period after the first AC is powered on comprises: The method of claim 6, wherein, performing the following operations within the first preset time period after the first AC is powered on until the first preset time period is reached, the following operations comprising: obtaining neighbor AP information reported by a first AP managed by the first AC; the neighbor AP information comprises AP identifiers respectively corresponding to each neighbor AP identified by the first AP; when a foreign AP identifier not belonging to the first AC is included in the neighbor AP information, adding the foreign AP identifier to a foreign AP list and broadcasting the foreign AP list within the roaming domain VLAN; and ​ If the second AC sends a response message to the first AC, the second AC is determined as a neighbor AC, wherein the response message is sent by the second AC when the second AC determines that the foreign AP list contains an AP identifier of the second AC. The method of claim 6, wherein, The roaming domain VLAN includes a plurality of ACs, and the plurality of ACs include the first AC. The at least one neighbor AC corresponding to the first AC is determined by a roaming trajectory learning manner within the first preset time period after the first AC is powered on, and the method comprises the following steps: The following operations are performed within the first preset time period after the first AC is powered on until the first preset time period is reached, and the operations comprise the following steps: In response to a second STA accessing a first AP managed by the first AC, if it is determined that the second STA is not associated with the first AC, a roaming query request is broadcasted in the roaming domain VLAN; If a response message sent by a third AC is received, the third AC is determined as a neighbor AC. The method of claim 8, wherein, Further comprising: If the response message sent by the third AC is received within a second preset time period, the second STA is allowed to roam between the first AC and the third AC; And If no response message is received within the second preset time period, the second STA is associated according to a first association strategy. The method of any one of claim 7, wherein, Further comprising: In the process of determining the at least one neighbor AC corresponding to the first AC, the type of the first AP is determined, and the type of the first AP is written into an internal AP list; The type is a border AP or an inland AP, each neighbor AP of the inland AP belongs to the APs managed by the first AC, and at least one neighbor AP of the border AP does not belong to the APs managed by the first AC; And If the type of the first AP is a border AP, a mapping relationship between the first AP and a corresponding neighbor AC is stored; The corresponding neighbor AC is an AC to which a neighbor AP of the first AP does not belong. The method of claim 10, wherein, If the at least one neighbor AC corresponding to the first AC is determined by exchanging foreign AP information, the type of the first AP is determined in the process of determining the at least one neighbor AC corresponding to the first AC, and the method comprises the following steps: When the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC, the type of the first AP is determined as a border AP; When each AP identifier in the neighbor AP information reported by the first AP belongs to the APs managed by the first AC, or when the neighbor AP information reported by the first AP contains a foreign AP identifier that does not belong to the first AC and no response message is received within a second preset time period, the type of the first AP is determined as an inland AP. The method of claim 10, wherein, If the at least one neighbor AC corresponding to the first AC is determined by a roaming trajectory learning manner, the type of each first AP is determined in the process of determining the at least one neighbor AC corresponding to the first AC, and the method comprises the following steps: determining the type of the access AP as a border AP if the response information sent by the third AC is received within a second preset time length after the roaming query request is broadcasted in the roaming domain VLAN; and determining the type of the access AP as an inland AP if the response information is not received within the second preset time length. The method of any one of claims 1-12, wherein The sending of the roaming query request to the at least one neighbor AC respectively comprises: sending the roaming query request to the at least one neighbor AC respectively in response to the number of ACs included in the roaming domain VLAN being greater than a first preset threshold, the neighbor AC being determined by means of exchanging foreign AP information and roaming track learning. The method of claim 13, wherein, The sending of the roaming query request to the at least one neighbor AC respectively comprises: sending the roaming query request to the at least one neighbor AC respectively in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the sending mode configured as sending the request to the neighbor AC, the neighbor AC being determined by means of roaming track learning. The method of claim 14, wherein, The method further comprises: broadcasting the roaming query request in the roaming domain VLAN in response to the number of ACs included in the roaming domain VLAN being less than or equal to the first preset threshold and the sending mode configured as roaming domain broadcast request; and making the first STA roam between the first AC and the fourth AC if the response information sent by the fourth AC is received. The receiving of the response information sent by the target neighbor AC comprises: The method of any one of claims 1-15, wherein, receiving the response information sent by the target neighbor AC through a tunnel between the first AC and the target neighbor AC. The making of the first STA roam between the first AC and the target neighbor AC comprises: The method of any one of claims 1-16, wherein the first AC establishing association with the first STA according to the response information, so as to make the first STA roam between the first AC and the target neighbor AC. A wireless terminal roaming apparatus, the apparatus being arranged in a first access controller (AC), the apparatus comprising: a sending module configured to, in response to a first wireless terminal (STA) accessing any wireless access point (AP) managed by the first AC, send a roaming query request to at least one neighbor AC respectively if it is determined that the first STA is not associated with the first AC; the at least one neighbor AC being an AC whose signal coverage range is adjacent to the signal coverage range of the first AC; and a roaming module configured to make the first STA roam between the first AC and a target neighbor AC if the response information sent by the target neighbor AC is received. a processor and a memory connected to the processor in communication; the memory storing computer-executable instructions; An access controller comprising: the processor executing the computer-executable instructions stored in the memory to implement the wireless terminal roaming method according to any one of claims 1 to 17. A computer-readable storage medium, the computer-readable storage medium storing computer-executable instructions, the computer-executable instructions being executed by a processor to implement the wireless terminal roaming method according to any one of claims 1 to 17. ​ ​

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