CN104380809A

CN104380809A - Access point selection method and device

Info

Publication number: CN104380809A
Application number: CN201380000335.7A
Authority: CN
Inventors: 王舜禹
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-06-05
Filing date: 2013-06-05
Publication date: 2015-02-25
Anticipated expiration: 2033-06-05
Also published as: WO2014194492A1; CN104380809B

Abstract

Embodiments of the present invention provide an access point (AP) selection method and device. The AP selection method of the present invention comprises: a centralized controller receiving status information sent by each AP, wherein the status information comprises load information about the AP that sends the status information; selecting at least one target AP that provides services for an STA according to the status information about each AP; sending a response message carrying a response policy to each AP, wherein the response policy is used to instruct the target AP to respond to an explorer frame broadcast by the STA and other APs not to respond to the explorer frame so that the STA selects a serving AP from the at least one target AP. The centralized controller according to embodiments of the present invention determines the target AP that provides wireless services for the STA according to the status information sent by each AP by responding to the explorer frame of the STA. Thus, the AP selection can be implemented in an optimal and efficient way.

Description

ACCESS POINT SELECTION METHOD AND DEVICE

The system of selection of access point and device

Technical field

The present embodiments relate to system of selection and the device of the communication technology, more particularly to a kind of access point.Background technology

The WLAN of operator（Wireless Local Area Network, abbreviation WLAN) it is by multiple thin access points（Access Point, abbreviation AP) management function put together, formed a new network element be access controller（Access Controller, abbreviation AC), manage the thin AP in configuration WLAN concentratedly using AC, form wireless network.

Work as work station（Station, abbreviation STA) need access wireless network when, by STA broadcast probe frames, AP replys probe response after receiving detection frame, STA can choose service AP according to the signal intensity of each AP probe responses replied afterwards, the service AP initiation association requests that certification is chosen backward are completed, the service AP of the selection returns to associated response to the STA, and STA just can carry out service interaction with the service AP of the selection after association is completed.During above-mentioned network insertion, selections of the STA to AP does not account for AP loading condition, when AP loads are very big, can have a strong impact on communication performance.In order to solve the problem, prior art is judged the service AP of selection loading condition to decide whether to respond STA, so as to realize the load balancing of AP selections after STA initiates association request to the service AP of selection by AC.

But, it is above-mentioned in the prior art, STA to AP to be associated send association request after, need the judgement for waiting AC to carry out load balancing, the delay of STA access networks is added, and STA and AC are selected service AP respectively, make AP efficiencies of selection not high；In addition, AC only considered AP load when to service AP selections, make the inadequate optimization of AP selections.The content of the invention

The embodiment of the present invention provides system of selection and the device of a kind of access point, to solve the problem of inefficient and AP of AP selections selects inadequate optimization, to realize the high efficiency and optimality of AP selections.

In a first aspect, the embodiment of the present invention provides a kind of system of selection of access point, including：

Centralized Controller receives the status information of at least one access point AP transmissions, the status information bag Include the load information for the AP for sending the status information；

The Centralized Controller is chosen at least one target AP that work station STA provides wireless service according to the status information of at least one AP;

The Centralized Controller sends the response message for carrying response policy at least one described AP, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, other AP are not responding to the detection frame of the STA broadcast, so that the STA selects to service AP from least one target AP.

In the first possible implementation of first aspect, the quality information of channel between AP and the STA of the status information also including sending the status information；

The Centralized Controller is chosen at least one target AP that STA provides wireless service according to the status information of at least one AP, including：

The Centralized Controller is chosen at least one target AP that the STA provides wireless service according to the quality information of channel between the load information and each AP and the STA of each AP at least one described AP.

According to the first possible implementation of first aspect or first aspect, in second of possible implementation, the status information is that at least one described AP is sent to the Centralized Controller after the detection frame of the STA broadcast is received, or at least one described AP periodicity or event triggering property are sent to the Centralized Controller.

According to first aspect, first aspect the first to second possible implementation any one, in the third possible implementation, the Centralized Controller at least one AP according to status information, it is chosen for after at least one target AP that STA provides wireless service, in addition to：

If at least one target AP does not include current service AP, and the Centralized Controller determines that the STA does not switch service AP in preparatory condition, then send and indicate that message indicates that the current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

According to first aspect, first aspect the first to the third possible implementation any one, in the 4th kind of possible implementation, the Centralized Controller receive at least one AP transmission status information after, in addition to：

The Centralized Controller determines whether to be stored with the list item of the STA, if so, then according to the state information updating STA list item；

If nothing, the list item of the STA is generated according to the status information；The list item of the STA is used The correspondence STA received in storage status information；

The status information that the Centralized Controller is stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.

According to first aspect the first to the 4th kind of possible implementation any one, in the 5th kind of possible implementation, the Centralized Controller is chosen for the target AP that STA provides wireless service according to the status information of at least one AP, including：

The Centralized Controller according at least one described AP between each AP and the STA channel quality information and pre-determined threshold, determine AP to be selected;

The Centralized Controller chooses at least one minimum AP of load as at least one target AP in the AP to be selected.

According to first aspect the first to the 5th kind of possible implementation any one, in the 6th kind of possible implementation, the quality information of the channel includes the signal strength information of channel between each AP to the STA at least one described AP, or, the up modulation that each AP is counted at least one described AP and coding strategy MCS bag distributed intelligences.

Second aspect, the embodiment of the present invention provides a kind of system of selection of access point, including：

Access point AP receives the response message for carrying response policy that Centralized Controller is sent, the response message is that the Centralized Controller is sent to the AP after the status information that the AP is sent is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to the detection frame of the STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；If the AP has been received by the detection frame of the STA broadcast, then whether at least one target AP includes the AP according to being determined the response policy, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

In the first possible implementation of second aspect, the quality information of channel between AP and the STA of the status information also including sending the status information；

At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, including： At least one target AP is that the quality information of channel between the load information of each AP in the Centralized Controller at least one AP according to and each AP and the STA is chosen for the STA.

According to the first possible implementation of second aspect or second aspect, in second of possible implementation, the AP is received before the response message for carrying response policy that Centralized Controller is sent, in addition to：

The AP sends the status information to the Centralized Controller after the detection frame of the STA broadcast is received；

Or, the AP is periodically or event triggering property sends the status information to the Centralized Controller.

According to second aspect, second aspect the first to second of possible implementation, in the third possible implementation, in addition to：

The AP receives the instruction message that the Centralized Controller is sent, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message is that the Centralized Controller determines that at least one target AP does not include current service AP, and determines that the STA does not switch what is sent during service AP in preparatory condition.

According to second aspect, second aspect the first to the third possible implementation, in the 4th kind of possible implementation, the AP is received after the response message for carrying response policy that Centralized Controller is sent, in addition to：

The AP sets up or updated the response policy of the STA according to the response policy.

According to the 4th of second aspect the kind of possible implementation, in the 5th kind of possible implementation, the AP is received before the response message for carrying response policy that Centralized Controller is sent, in addition to：The AP receives the detection frame of the STA broadcast；

The AP determines whether to be stored with the response policy of the STA, if nothing, the status information of the AP is then sent to the Centralized Controller, to cause the Centralized Controller to obtain the status information of the AP, it is determined that at least one target AP, and send the response message for carrying the response policy.

The third aspect, the embodiment of the present invention provides a kind of Centralized Controller, including：

First receiving module, the status information for receiving at least one access point AP transmissions, the status information includes sending the AP of status information load information；

Processing module, the status information for being received according to first receiving module is chosen at least one target AP that work station STA provides wireless service; Sending module, the response message for carrying response policy is sent at least one described AP at least one target AP according to processing module selection, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, other AP are not responding to the detection frame of the STA broadcast, so that the STA selects to service AP from least one target AP.

In the first possible implementation of the third aspect, the processing module is additionally operable to：If between AP and the STA of the status information also including sending the status information during quality information of channel, according to the quality information of channel between the load information and each AP and the STA of each AP at least one described AP, at least one target AP that the STA provides wireless service is chosen for.

According to the first possible implementation of the third aspect or the third aspect, in second of possible implementation, the processing module is additionally operable to：In the status information according at least one AP, it is chosen for after at least one target AP that STA provides wireless service, if at least one target AP does not include current service AP, and determine that the STA does not switch service AP in preparatory condition, then send and indicate that message indicates that the current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

According to the third aspect, the third aspect the first to second of possible implementation, in the third possible implementation, the processing module is additionally operable to：After the status information for receiving at least one AP transmissions, it is determined whether the list item for the STA that is stored with, if so, then according to the state information updating STA list item, if nothing, the list item of the STA is generated according to the status information；The list item of the STA is used for the status information for storing the correspondence STA received；The status information stored according to the list item of the STA, is chosen at least one described target fourth aspect that the STA provides wireless service, and the embodiment of the present invention provides a kind of access point apparatus, including：

Second receiving module, the response message for carrying response policy for receiving Centralized Controller transmission, the response message is that the Centralized Controller is sent to the AP after the status information of access point AP transmissions is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to the detection frame of the STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；

Respond module, if the detection frame for having been received by the STA broadcast, according to the response plan Slightly determine whether at least one target AP includes the AP, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

In the first possible implementation of fourth aspect, the quality information of channel between AP and the STA of the status information also including sending the status information；

At least one target AP is that the Centralized Controller is chosen according to the status information that at least one AP is sent, including：

At least one target AP is that the quality information of channel between the load information of each AP in the Centralized Controller at least one AP according to and each AP and the STA is chosen for the STA.

According to the first possible implementation of fourth aspect or fourth aspect, in second of possible implementation, the respond module is additionally operable to：

Receive the instruction message that the Centralized Controller is sent, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message is that the Centralized Controller determines that at least one target AP does not include current service AP, and determines that the STA does not switch what is sent during service AP in preparatory condition.

5th aspect, the embodiment of the present invention provides a kind of Centralized Controller, including receiver, processor and memory, wherein：

The receiver is used for the status information for receiving at least one access point AP transmissions, and the status information includes sending the AP of status information load information；

The memory storage has batch processing code, and the processor calls described program code, to perform following operation：According to the status information of at least one AP, it is chosen at least one target AP that work station STA provides wireless service, the response message for carrying response policy is sent at least one described AP, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, and other AP are not responding to the detection frame of the STA broadcast；So that the STA selects to service AP from least one target AP.

The memory is additionally operable to store the response policy.

In the first possible implementation of the 5th aspect, the quality information of channel between AP and the STA of the status information also including sending the status information.

6th aspect, the embodiment of the present invention provides a kind of access point apparatus, including：

Receiver, the response message for carrying response policy for receiving Centralized Controller transmission is described Response message is that the Centralized Controller is sent to the AP after the status information of access point AP transmissions is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to the detection frame of the STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；

Processor, if the detection frame for having been received by the STA broadcast, whether at least one target AP includes the AP according to being determined the response policy, if, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

In the first possible implementation of the 6th aspect, the quality information of channel between AP and the STA of the status information also including sending the status information.

The system of selection of access point of the embodiment of the present invention and device, Centralized Controller is defined as the target AP that STA provides wireless service according to each AP status informations sent, to respond STA detection frame, service AP is selected from these targets AP for STA, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved.Meanwhile, in the present embodiment, the control done when due to AC being to AP echo probe frames, relative to for the control that AP responds association request, reducing the network insertion stand-by period of user in the prior art.Brief description of the drawings

In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, the required accompanying drawing used in embodiment or description of the prior art will be briefly described below, apparently, drawings in the following description are some embodiments of the present invention, for those of ordinary skill in the art, without having to pay creative labor, other accompanying drawings can also be obtained according to these accompanying drawings.

Fig. 1 is the flow chart of the system of selection embodiment one of access point of the present invention；

Fig. 2 is the flow chart of the system of selection embodiment two of access point of the present invention；

Fig. 3 is the flow chart of the system of selection embodiment three of access point of the present invention；

Fig. 4 is the flow chart of the system of selection example IV of access point of the present invention；

Fig. 5 is the signaling process figure of the system of selection embodiment five of access point of the present invention；

Fig. 6 is the signaling process figure of the system of selection embodiment six of access point of the present invention；

Fig. 7 is the structural representation of Centralized Controller embodiment one of the present invention； Fig. 8 is the structural representation of AP apparatus embodiments one of the present invention；

Fig. 9 is the structural representation of Centralized Controller embodiment two of the present invention;

Figure 10 is the structural representation of AP apparatus embodiments two of the present invention.Embodiment is to make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is a part of embodiment of the invention, rather than whole embodiments.Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made belongs to the scope of protection of the invention.

Fig. 1 is the flow chart of the system of selection embodiment one of access point of the present invention, and the access that this method is applied to wireless network is selected, and is based especially on the access selection of the wireless network of AP load balancing.This method can be completed with Centralized Controller and AP, and not have any requirement to STA and procotol, completely by network side（Such as AP and AC) control, compatibility height.Wherein, the entity of the Centralized Controller is not limited to AC, can be independent server, or a certain specific AP, as long as the centralized control functions to each AP can be realized.Meanwhile, the typical WLAN networkings that the wireless network is not limited to the wlan network of operator or formed by fat AP.Following all embodiments are using Centralized Controller as AC, and wireless network is illustrates exemplified by the wlan network of operator, as shown in figure 1, this method can be carried out according to following flow：

S101, Centralized Controller receive the status information of at least one AP transmissions, and the status information includes sending the AP of status information load information.

Wherein, the load information is used to reflect the current load conditions of AP for sending the status information, can include the use dutycycle AP currently, association user number, concurrent user number, one of information such as flow or any combination；

Preferably, the quality information of channel between the status information can also be including sending the status information AP and the STA.The quality information of the channel is used for the quality for reflecting the communication channel at least one AP between each AP and the STA, can include each AP up modulation of each AP statistics and coding strategy into the signal strength information of the STA and/or at least one AP at least one AP（Modulation and Coding Scheme, abbreviation MCS) bag distributed intelligence.

Alternatively, the status information can be that at least one AP is receiving the spy of STA broadcast Survey be sent to Centralized Controller after frame or at least one AP periodically or event triggering property is sent to Centralized Controller, no limitations are hereby intended.Wherein, event triggering property can be triggered by the channel quality thresholds value set, such as, if servicing AP judges that the channel quality with STA can send status information when being less than the threshold value set to AC, and for example, non-serving AP judges that the channel quality with STA can send status information when being higher than the threshold value set to AC；Event triggering property can also be what is triggered by the data packetloss rate set, but be not limited, and herein by way of example only, can be configured according to actual conditions.

S102, Centralized Controller are chosen at least one target AP that STA provides wireless service according to the status information of at least one AP.

For example, in the status information that AC is sent according at least one AP each AP load information, choose the minimum multiple AP of load as at least one target AP, service AP select from least one target AP according to signal intensity for the STA.

Preferably, if the quality information of channel between AP and the STA that the status information can also be including sending the status information, that is the status information that at least one AP that AC is received is sent can also include the quality information of channel between each AP and STA, then AC is chosen for the target AP that the STA provides wireless service according to the quality information of channel between the load information and each AP and the STA of each AP at least one AP.The selection process can be carried out in accordance with the following methods：

Method one

AC is pre-set after a load-threshold value, handles the load information in the status information, regard at least one AP loaded less than the load-threshold value as AP to be selected;AC is further according to the quality information of channel, and the good one or more AP of selection channel quality are used as at least one target APo from AP to be selected

If AP load is above the load-threshold value, AC can not choose target AP, can also load less one or more AP according to load information selection and be used as at least one target AP.

Or, AC can be not provided with the load-threshold value, direct at least one AP small according to the selection load of each AP load information selects the good one or more AP of channel quality as at least one target AP as AP to be selected, the then quality information further according to channel from AP to be selected.

Method two

Centralized Controller determines AP to be selected according to the quality information and pre-determined threshold of the channel at least one AP between each AP and the STA;It is minimum that Centralized Controller chooses load in the AP to be selected At least one AP be used as at least one target AP.This have the advantage that, the AP for selecting channel quality very poor can be avoided as target AP, it is ensured that target AP optimality.

Specifically, AC pre-sets a channel quality thresholds value, handles the quality information of the channel in the status information, regard at least one AP that the channel quality is more than the channel quality thresholds value as AP to be selected;AC is further according to load information, and the low one or more AP of selection load are used as at least one target AP from AP to be selected.

If AP channel quality is below the channel quality thresholds value, AC can not choose target AP, channel quality preferably one or more AP can also be selected to be used as at least one target AP according to the quality information of channel.

Or, AC can be not provided with the channel quality thresholds value, at least one high AP of channel quality is directly chosen as AP to be selected, the one or more AP for then selecting load small from AP to be selected further according to load information according to each AP channel quality and is used as target AP.

Above two method by way of example only, to target AP selection can flexible specified rule, such as statistical forecast based on historical data as needed, no limitations are hereby intended, as long as target AP selection can be realized.

Wherein, at least one target AP can be one or more, if one, it can then indicate that the STA is directly set up with a target AP to associate, so as to set up or update wireless connection, this have the advantage that, optimal service AP can be provided for STA, target AP is selected without the need for STA, wireless network access efficiency is improved；If multiple, then it can indicate that the STA selects to service AP from the plurality of target AP, i.e., autonomous selection services AP from the target AP of multiple optimizations by the STA, improves STA independence and flexibility.

S103, Centralized Controller send the response message for carrying response policy at least one AP, the response policy is used for the detection frame for indicating that at least one target AP responds STA broadcast, other AP are not responding to the detection frame of STA broadcast, so that the STA selects to service AP from least one target AP.

Specifically, it is determined that after at least one target AP, AC generation response policies, the response policy is used to indicate that target AP responds the detection frame, probe response is sent to the STA when receiving the detection frame of STA broadcast, so that the STA chooses service AP;The response policy is additionally operable to indicate that other AP are not responding to the detection frame, i.e., do not send probe response to the STA when receiving the detection frame of STA broadcast.Wherein, other AP are in AC receives the AP of status information, to remove It is chosen for the AP beyond target AP.

The response policy is sent at least one AP by AC, at least one AP determines whether to respond the detection frame of the STA according to the response policy, so that the STA selects service AP to initiate association request from target AP, so as to be set up with target AP or update wireless connection.The renewal wireless connection can include：The roaming of wireless network or the association again of wireless connection.

Wherein, if not setting up wireless network before the STA, or disconnected with wireless network, then the STA selects service AP to set up wireless connection from least one target AP；If the STA now has service AP, the STA selects new service AP to carry out service AP switching from least one target AP, realizes the roaming of wireless network or associates again.

The present embodiment, Centralized Controller is defined as the target AP that STA provides wireless service according to each AP status informations sent, to respond STA detection frame, service AP is selected from these targets AP for STA, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved.Meanwhile, in the present embodiment, the control done when due to AC being to AP echo probe frames, relative to for the control that AP responds association request, reducing the network insertion stand-by period of user in the prior art.

Alternatively, Centralized Controller is chosen for after at least one target AP that STA provides wireless service, can also included according to the status information of at least one AP：If at least one target AP does not include current service AP, and Centralized Controller determines that the STA does not switch service AP in preparatory condition, then send and indicate that message indicates that current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

Specifically, AC judges whether the STA has currently set up wireless connection according to the status information, if, at least one target AP can be chosen according to the status information of at least one AP, and judge whether include the AP that wireless service is currently provided for the STA at least one target AP chosen, if, then AC can not generate response policy, if not, then AC sets a preparatory condition, so that the STA independently switches service AP according to own situation, if reaching after preparatory condition, the STA is not switched independently, then AC indicates currently to provide the AP releasings of wireless service and associating for the STA for the STA, detection frame is re-broadcast to trigger the STA, and indicate that at least one target AP responds the detection frame.Wherein, the preparatory condition can include but is not limited to：Default set time or wireless media channel quality.For example, the preparatory condition can be a preset time period, after the period, the STA is not switched independently also, then enforces de-association；Or the preparatory condition can be pre- If wireless media channel quality threshold, such as signal quality threshold value or packet loss threshold value, if less than these threshold values, the STA is not switched independently also, then enforces de-association.This have the advantage that, AC can dynamically adjust the load of wireless network, it is ensured that AP load balancing in wireless network, and ensure that the AP for providing service again is the AP that performance optimizes.

The present embodiment is illustrated from two scenes below：

Scene one, STA do not set up wireless connection currently

, it is necessary to which broadcast probe frame, neighbouring AP is received after the detection frame before STA access wireless networks, probe response is not returned to directly, but can send status information to AC.AC receives the status information of at least one AP transmissions, and the status information can be that AP is sent to AC after the detection frame of STA transmissions is received.

AC is chosen for the target AP that STA provides wireless service according to status information is received, and generates response policy.Wherein, the response policy is consistent with the above, and it is chosen, and process is also similar to the above, and here is omitted.And target AP can be one, or multiple, it can be chosen according to actual conditions.

AC sends response policy at least one AP, so that the target AP of selection responds the detection frame, and, as AP is serviced, wireless connection is set up to indicate the STA from the selection one in those targets AP.

The currently-established wireless connection of scene two, STA

When STA has accessed wireless network, AC receives the status information of at least one AP transmissions, and the status information can be AP periodically or event triggering property is sent to AC.

AC is chosen for the target AP that STA provides wireless service according to status information is received, and generates response policy.Wherein, the response policy is consistent with the above, and it is chosen, and process is also similar to the above, and here is omitted.And target AP can be multiple, this have the advantage that, because AC can not predict STA randomnesss on the move in real time, in order to ensure that STA can be rapidly switched to target AP according to the system mechanism of itself, multiple selectable target AP are provided, to prevent because the problem of updating caused network insertion handoff not in time, the compatibility and fault-tolerance of network insertion are improved.

AC sends response policy at least one AP, so that target AP sends probe response when receiving the detection frame of STA broadcast to the STA, to indicate that the STA selects a target AP to be used as new service AP from target AP, to carry out the switchings of the service AP in wireless network Complete the roaming in wireless network or associate again.

Fig. 2 is the flow chart of the system of selection embodiment two of access point of the present invention, and the present embodiment is on the basis of above-described embodiment, after S 101, can also include：Centralized Controller determines whether to be stored with the list item of the STA, if so, then according to the state information updating STA list item；If nothing, the list item of the STA is generated according to the status information；The list item of the STA be used for store receive to should STA status information；S 102 can include：The status information that Centralized Controller is stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.This method can be applied not only to the situation that STA prepares access wireless network, the situation of STA accessed networks can also be applied to, as shown in Fig. 2 this method can be carried out according to following flow：

5201st, Centralized Controller determines whether to be stored with the list item of the STA, if so, then according to the state information updating STA list item；If nothing, the list item of the STA is generated according to the status information；The list item of the STA be used for store receive to should STA status information.

Specifically, AC is received after the status information of at least one AP transmissions, Check can be carried out from the list item list for the STA being locally stored first to look for, whether it is already present in the list with the list item for determining the STA, if, then according to the state information updating STA received list item, in case AC chooses at least one target AP according to newest STA list item;If it is not, then according to the newly-built STA of status information list item, in case AC directly updates the list item when receiving the status information related to the STA again, while in case AC chooses at least one target AP o according to newest STA list item

Wherein, the list item list of the STA is created and is being locally stored by AC, to facilitate AC to collect the status information received, beneficial to the selection to target AP；The list item list of the STA can include multiple STA list item, and each STA list item can include each AP related to the STA received status information.

5202nd, the status information that Centralized Controller is stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.

For example, AC from the STA of the list item list records for the STA being locally stored list item, passes through the calculating and decision-making to load information and the quality information of channel after certain time is waited, which AP decisions allows as target AP echo probe frames, and which AP is not responding to detect frame.Wherein, should Response policy is consistent with foregoing response policy, and here is omitted.

For example, when being chosen, in STA list item, in the presence of at least one AP status information, STA to AP signal intensity is first determined whether, is higher than the signal strength threshold value set, just thinks that this AP preferably can provide wireless service for STA, this part AP is participated in into Yi Walk selection as preferred AP, and alternately AP participates in tactful judgement to remaining AP.In preferred AP, selection load is low or load is less than the detection frame that STA is responded as target AP of average value, if without preferred AP, identical selection is carried out in alternative AP.Final Response Decision is sent to each AP.

Specifically, S202 can be carried out according to following flow：

Walk rapid one, Centralized Controller judge whether the STA has set up wireless connection according to the list item of the STA：If so, then Zhi Hang Walk rapid two；If it is not, then Zhi Hang Walk rapid three.

Specifically, AC judges according to the list item of the STA wireless connection conditions current to STA first, with the response policy generated after determination.

Walk rapid two, Centralized Controller choose at least one target AP according to the list item of the STA, and generate the response policy, so that the STA independently carries out wireless network roaming or associates again.

Specifically, if judging, the current STA has set up wireless connection, then AC chooses at least one target AP according to the list item of the STA, and indicate that these targets AP returns to probe response when receiving the detection frame of the STA, so that the STA therefrom selects target AP to carry out the renewal of wireless connection as service AP, that is, carry out wireless network roaming and associate again.This have the advantage that, the AP for carrying out wireless network switching is provided for STA, to realize the autonomous demands switched over to AP of STA, it is ensured that compatibility, fault-tolerance is improved.

Walk rapid three, Centralized Controller are chosen at least one target that the STA provides wireless service according to the list item of the STA_AP, and generate the response policy.

Specifically, such as judge that the current STA does not set up wireless connection, then AC can choose the target AP of multiple best performances according to the list item of the STA, so that the STA therefrom selects service AP to set up wireless connection, or the target AP of a best performance is chosen, so that the STA directly sets up wireless connection with target AP.

Alternatively, it can also include after S202：If at least one target AP does not include current service AP, and Centralized Controller determines that the STA does not switch service AP in preparatory condition, then sends and indicate that message indicates that current service AP sends disassociation message to the STA, to trigger the STA Re-broadcast detection frame.Specifically, AC is after the currently-established wireless connections of the STA are judged, Jin mono- Walk, AC can choose at least one target AP according to the list item of the STA, and judge whether at least one target AP chosen includes current service AP, if, then AC can not generate response policy, if not, then AC determined in preparatory condition the STA independently switching service AP after, instruction current service AP releasings are associated with the STA's, detection frame is re-broadcast to trigger the STA, and indicate that target AP responds the detection frame, it is the AP that performance optimizes to ensure the AP for re-establishing association.This have the advantage that, AC can dynamically adjust the load of wireless network, it is ensured that the load balancing of wireless network.

The present embodiment, by the way that the simultaneously STA of real-time update list item list is locally created in Centralized Controller, realizes and the dynamic that AP is selected is adjusted, and assigns real-time response policy, optimizes the loading condition of wireless network, and ensure that the compatibility of network.

Illustrated below by taking the scene that STA has set up wireless connection as an example：

Each AP is received after each STA detection frame, can periodically or event triggering property to AC send status information, AC is according to these status informations, set up or update each STA list item, and according to the Refresh Data STA updated every time list item list, STA for having built up wireless connection, AC can judge whether STA is in best server cell according to STA to AP channel quality condition（Whether the AP for providing wireless service is optimal）, judgement herein can use the signal strength information of STA to the AP in AP status informations, the up MCS bags distributed intelligence that can also be counted according to AP etc., no longer detailed herein to illustrate.If STA to AP signal intensity is less than threshold value, then think that this STA has been no longer on best server cell, now examine Check STA list item, judged according to STA to AP signal strength thresholds, preferred AP (i.e. above-mentioned AP to be selected) is used as higher than threshold value, less than the alternately AP of threshold value, if preferred AP, then Ke Jin mono- Walk judge preferred AP load state, sequence can be used, the mode for being compared or being compared with preset value with class mean, do not limit herein, select load meet condition as target AP, if without preferred AP, then in alternative AP, AP sequences are carried out with signal intensity, only when alternative AP signal intensity is persistently better than current service AP, or it is better than current AP signal intensity plus the inclined of signal intensity When putting, AP to be selected could be used as, if multiple alternative AP signal intensity is all persistently better than current service AP, then these alternative AP signal need to be compared with most strong alternative AP signal, the alternative AP in the range of certain signal strength variance, AP to be selected can be all used as, in these AP to be selected, duty factor is carried out compared with the mode for sequence can be used, being compared or being compared with preset value with class mean, do not limit herein, finally select target AP.

AC sends newest response policy to each AP, the target AP selected response policy is echo probe, remaining AP response policy is to be not responding to, by so, triggering terminal carries out service AP switchings, if terminal is without switching, Ke Jin mono- Walk allow current service AP and STA disassociations, trigger STA and broadcast new detection frame, because STA can only have found selected target AP in network, therefore STA can only be associated with target AP, reach that guiding STA switches to the service AP of selection purpose.Because target AP combines channel circumstance and load synthesis is elected, by switching, the load allowed between AP purpose more in a balanced way is reached.

Fig. 3 is the flow chart of the system of selection embodiment three of access point of the present invention, as shown in figure 3, this method can be carried out according to following flow：

S301, AP receive the response message for carrying response policy that Centralized Controller is sent, the response message is that Centralized Controller is sent to the AP after the status information of AP transmissions is received, the detection frame at least one target AP response STA broadcast that the response policy is used to indicate to receive in the AP of the response message, other AP are not responding to the detection frame of STA broadcast；At least one target AP is that Centralized Controller is chosen according to the status information that at least one AP is sent, and the status information includes sending the AP of status information load information.

Specifically, the status information can include AP load information.The load information of the AP is used to reflect the current load conditions of the AP, can include the use dutycycle AP currently, association user number, concurrent user number, one of information such as flow or any combination；

Preferably, the status information can also include the quality information of channel between AP and STA, then to be AC choose at least one target AP according to the quality information of channel between the load information and each AP and the STA of each AP at least one AP.The quality information of the channel is used for the quality for reflecting the communication channel at least one AP between each AP and the STA, can include the up MCS bags distributed intelligence of each AP each AP statistics into the signal strength information of the STA and/or at least one AP at least one AP.

Alternatively, before S301, it can also include：The AP is receiving STA broadcast The status information is sent to Centralized Controller after detection frame；Or, the AP is periodically or event triggering property sends the status information to Centralized Controller, and no limitations are hereby intended.

Jin mono- Walk, if the status information can be sent to AC by AP periodicity or event triggering property, it becomes possible to realize dynamic controls of the AC to wireless network, adjustment AP loading condition, optimizes the working condition of wireless network in good time.

Wherein, at least one target AP can be one, or multiple, can be chosen according to actual conditions.

If S302, the AP have been received by the detection frame of STA broadcast, determine whether at least one target AP includes the AP according to the response policy, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

Specifically, whether the AP is in itself one of at least one target AP according to the response policy judgement received, in this way, the then echo probe frame after STA detection frame is received, so that the STA can be found that the AP, so that the STA can select to set up wireless connection with the AP.If judgement is not included at least one target AP in itself, the AP is not responding to the detection frame when receiving the detection frame of STA broadcast.

The present embodiment, AP receives the response message for carrying response policy, and determined whether to respond the detection frame that STA is broadcasted according to the response policy, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved.Meanwhile, in the present embodiment, the control done when due to AC being to AP echo probe frames, relative to for the control that AP responds association request, reducing the network insertion stand-by period of user in the prior art.

Alternatively, the present embodiment can also include on the basis of above-described embodiment：The AP receives the instruction message that Centralized Controller is sent, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message is that Centralized Controller determines that at least one target AP does not include current service AP, and determines that the STA does not switch what is sent during service AP in preparatory condition.Specifically, the AP is current service AP, if not including current service AP in target AP, also not autonomous switching services AP to the STA in preparatory condition, the instruction message that then AP is sent according to AC, disassociation message is sent to the STA, new detection frame is broadcasted to trigger the STA.

Fig. 4 is the flow chart of the system of selection example IV of access point of the present invention, and the present embodiment is on the basis of Fig. 3 illustrated embodiments, and this method can also include before S301：The AP is according to the response Strategy, sets up or updates the response policy of the STA.Jin mono- Walk, can also include after S301：The AP receives the detection frame of STA broadcast；The AP determines whether to be stored with the response policy of the STA, if nothing, the status information of the AP is sent to Centralized Controller, to cause Centralized Controller to obtain the status information of the AP, at least one target AP is determined, and sends the response message for carrying the response policy.As shown in figure 4, this method can be carried out according to following flow：

5401st, the AP receives the detection frame of STA broadcast.

5402nd, the AP determines whether to be stored with the response policy of the STA, if nothing, the status information of the AP is then sent to Centralized Controller, to cause Centralized Controller to obtain the status information of the AP, at least one target AP is determined, and sends the response message for carrying the response policy.

Specifically, after AP receives the detection frame of STA broadcast, it is not directly in response to the detection frame, but response policies of the Check in the STA that locally whether is stored with is examined first, if, show via Centralized Controller to judge, directly determine whether to respond the detection frame according to response policy；If not provided, being accomplished by the state information report of the relevant information including STA to AC, judged by AC, that is, continue executing with S301.

5403rd, the AP sets up or updated the response policy of the STA according to the response policy.

The present embodiment, Check is first examined before STA detection frame is received by AP locally whether to be stored with the response policy of the STA, if so, directly handling the detection frame of the STA according to the response policy, the access efficiency of wireless network is improved in Centralized Controller dynamically management wireless network.

Fig. 5 is the signaling process figure of the system of selection embodiment five of access point of the present invention, the present embodiment is not in case of STA currently sets up wireless connection in the wireless network, simultaneously with wireless network by 3 AP (API, AP2 and AP3) composition exemplified by illustrate, as shown in figure 5, this method can be with Carried out according to following flow：

5501st, STA broadcast probes frame.

5502nd, API, AP2 and AP3 send status information to AC.

Before this Walk of are rapid, it AP1, AP2 and AP3 can also be included first examine Check locally whether being stored with the response policy of the STA.Because the STA in the present embodiment did not set up wireless connection with the wireless network, so directly will not directly be handled according to the response policy being locally stored.

5503rd, AC generates response policy according to status information.

During this Walk is rapid, AC can preset an acquisition time to the reception of status information, reach after acquisition time, begin to calculate and decision-making, to generate response policy.For example, indicating that API responds the detection frame, AP2 and AP3 are not responding to detect frame.

5504th, AC sends the response message for carrying response policy to AP1, AP2 and AP3.

5505th, API sends probe response to STA.

5506th, STA sends association request to API.

5507th, API sends associated response to STA.

Fig. 6 for access point of the present invention system of selection embodiment six signaling process figure, the present embodiment with

STA has currently set up the situation of wireless connection in the wireless network, as set up with AP2 exemplified by wireless connection, simultaneously equally with wireless network by 3 AP (API, AP2 and AP3) composition exemplified by illustrate, as shown in fig. 6, this method can be carried out according to following flow：

S601, API, AP2 and AP3 are periodically or event triggering property sends status information.

S602, AC generate response policy according to status information.

During this Walk is rapid, AC chooses AP1, AP2 and AP3 as target AP according to the status information, and switching service AP is chosen whether according to own situation to trigger STA;Or AC only chooses API and AP3 as target AP, to trigger STA switching services AP.

Yi Xia Walk is rapid chooses API and AP3 using AC and illustrated as target AP.

S603, AC send the response message for carrying response policy to AP1, AP2 and AP3.

5604th, STA broadcast probes frame.

During this Walk is rapid, STA can independently switch service AP, and frame is detected to wireless network broadcast.

5605th, API and AP3 sends probe response to STA.

During this Walk is rapid, AP1, AP2 and AP3 first determine whether locally whether store the response policy of the STA, may indicate that AP1, AP2 and AP3 are locally stored with the response of the STA according to S603 Strategy.

Because the AP2 response policies being locally stored are to be not responding to, then AP2 is failure to actuate.

5606th, STA is released associates with AP2.

Alternatively, it is rapid without this Walk if STA carries out wireless network roaming before this Walk of are rapid;If STA prepares disconnection of wireless connection, access again again afterwards, then perform this Walk rapid.

5607th, STA sends association request to API.

During this Walk is rapid, STA is by judging, selection API is used as service AP.

5608th, API sends associated response to STA.

Alternatively, in the present embodiment, the status information that AC can also be received according to periodicity or event triggering property judges whether the target AP chosen is consistent with the current AP that wireless service is provided for STA, if not, decision making response policy can be first passed through, indicate that one or more target AP respond the detection frame that the STA will be broadcasted, if the STA attonitys within a certain period of time, i.e. without the roaming for independently carrying out wireless connection or without association service AP again, it can indicate to provide the AP releasings of service and associating for the STA, detection frame is sent so as to trigger the STA, to re-establish association.

Fig. 7 is the structural representation of Centralized Controller embodiment one of the present invention, as shown in fig. 7, the Centralized Controller can include：First receiving module 71, processing module 72 and sending module 73.Wherein, first receiving module 71 can be used for receiving the status information that at least one access point AP is sent, and the status information can include the load information for sending the AP of the status information；The status information that the processing module 72 can be used for being received according to first receiving module 71 is chosen at least one target AP that the STA provides wireless service;At least one target AP that the sending module 73 can be used for being chosen according to the processing module 72 sends the response message for carrying response policy at least one AP, the response policy is used for the detection frame for indicating at least one target AP response STA broadcast, other AP are not responding to the detection frame of STA broadcast, so that the STA selects to service AP from least one target AP.

Alternatively, the processing module 72 can be also used for：If between AP and the STA that the status information can also be including sending the status information during quality information of channel, according to the quality information of channel between the load information and each AP of each AP at least one AP and the S T A, at least one target AP that the S T A provide wireless service is chosen for.

Alternatively, the processing module 72 can be also used for：In the status information according at least one AP, it is chosen for after at least one target AP that STA provides wireless service, if at least one mesh Marking AP does not include current service AP, and determines that the STA does not switch service AP in preparatory condition, then sends and indicate that message indicates that current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

Alternatively, the processing module 72 can be also used for：After the status information for receiving at least one AP transmissions, it is determined whether the list item for the STA that is stored with, if so, then according to state information updating STA list item, if nothing, the list item of the STA is generated according to the status information；The list item of the STA be used for store receive to should STA status information；The status information stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.

The device of the present embodiment, can be used for the technical scheme for performing embodiment of the method shown in Fig. 1 and Fig. 2, and its concrete function refers to above method embodiment, and here is omitted.

The Centralized Controller of the present embodiment, by processing module according to the first receiving module receive it is each

The status information that AP is sent is defined as at least one target AP that STA provides wireless service, and the response message for carrying response policy is sent to each AP by sending module, so that target AP responds STA detection frame, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved.

Fig. 8 is the structural representation of AP apparatus embodiments one of the present invention, as shown in figure 8, the AP equipment can include：Second receiving module 81 and respond module 82.Wherein, second receiving module 81 can be used for receiving the response message for carrying response policy that Centralized Controller is sent, the response message is that Centralized Controller is sent to the AP after the status information of AP transmissions is received, the response policy can serve to indicate that the detection frame of at least one target AP response STA broadcast in the AP for receiving the response message, and other AP are not responding to the detection frame of STA broadcast；At least one target AP is that the status information that Centralized Controller is sent according at least one AP is chosen for the STA, and the status information can include the load information for sending the AP of the status information；；If the respond module 82 can be used for the detection frame for having been received by STA broadcast, then determine whether at least one target AP includes the AP according to the response policy, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

Alternatively, the quality information of channel between the status information can also be including sending the status information AP and the STA；Then at least one target AP be Centralized Controller according to the status information that at least one AP is sent can including for choosing：At least one target AP is Centralized Controller according to the quality of channel between the load information and each AP and the STA of each AP at least one AP Information is what the STA chose.

Alternatively, the respond module 82 can be also used for：Receive the Centralized Controller and send instruction message, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message can be that Centralized Controller determines that at least one target AP does not include current service AP, and determine that the STA does not switch what is sent during service AP in preparatory condition.

The device of the present embodiment, can be used for the technical scheme for performing embodiment of the method shown in Fig. 3 and Fig. 4, and its concrete function refers to above method embodiment, and here is omitted.

The AP equipment of the present embodiment, the response message for carrying response policy is received by the second receiving module, and determined whether to respond the detection frame that STA is broadcasted according to response policy by respond module, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved.

Fig. 9 is the structural representation of Centralized Controller embodiment two of the present invention, as shown in figure 9, the Centralized Controller can include：Receiver 91, processor 92 and memory 93, wherein：The receiver 91 can be used for receiving the status information that at least one AP is sent, and the status information can include the load information for sending the AP of the status information；The memory 93 can be stored with batch processing code, and the processor 92 can call the program code, to perform following operation：According to the status information of at least one AP, it is chosen at least one target AP that STA provides wireless service, the response message for carrying response policy is sent at least one AP, the response policy can serve to indicate that at least one target AP responds the detection frame of STA broadcast, and other AP are not responding to the detection frame of STA broadcast；So that the STA selects to service AP from least one target AP.The memory 93 can be also used for storing the response policy.

Alternatively, the quality information of channel between the status information can also be including sending the status information AP and the STA.

The Centralized Controller of the present embodiment, the status information that each AP received by processing module according to the first receiving module is sent is defined as at least one target AP that STA provides wireless service, and the response message for carrying response policy is sent to each AP by sending module, so that at least one target AP responds STA detection frame, realize the optimality and high efficiency of AP selections, the load balancing of wireless network is ensure that, the problem of AP efficiencies of selection are not high not enough to be optimized with AP selections is solved. Figure 10 is the structural representation of AP apparatus embodiments two of the present invention, and as shown in Figure 10, the AP equipment can include：Receiver 101 and processor 102.Wherein, the receiver 101 can be used for receiving the response message for carrying response policy that Centralized Controller is sent, the response policy can be used for receiving the response message for carrying response policy that Centralized Controller is sent, the response message is that Centralized Controller is sent to the AP after the status information of AP transmissions is received, the detection frame at least one target AP response STA broadcast that the response policy is used to indicate to receive in the AP of the response message, other AP are not responding to the detection frame of STA broadcast；At least one target AP is that the status information that Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；If the processor 102 can be used for the detection frame for having been received by STA broadcast, then determine whether at least one target AP includes the AP according to the response policy, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

In several embodiments provided by the present invention, it should be understood that disclosed apparatus and method, it can realize by another way.For example, device embodiment described above is only schematical, for example, the division of the unit, it is only a kind of division of logic function, there can be other dividing mode when actually realizing, such as multiple units or component can combine or be desirably integrated into another system, or some features can be ignored, or do not perform.Another, it, by some interfaces, the INDIRECT COUPLING or communication connection of device or unit, can be electrical, machinery or other forms that shown or discussed coupling or direct-coupling or communication connection each other, which can be,.

The unit that this illustrates as separating component can be or may not be physically separate, the part shown as unit can be or may not be physical location, a place can be located at, or can also be distributed on multiple NEs.It can be selected according to the actual needs In some or all of unit realize the purpose of this embodiment scheme.

In addition, each functional unit in each of the invention embodiment can be integrated in a processing unit or unit is individually physically present, can also two or more units it is integrated in a unit.Above-mentioned integrated unit can both be realized in the form of hardware, it would however also be possible to employ hardware adds the form of SFU software functional unit to realize.

The above-mentioned integrated unit realized in the form of SFU software functional unit, can be stored in a computer read/write memory medium.Above-mentioned SFU software functional unit is stored in a storage medium, including some instructions are to cause a computer equipment（Can be personal computer, server, or network equipment etc.）Or processor（Processor the present invention each embodiment methods described Bu Fen Walk) are performed rapid.And foregoing storage medium includes：U disks, mobile hard disk, read-only storage（Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disc or CD etc. are various can be with the medium of store program codes.

Those skilled in the art can be understood that, for convenience and simplicity of description, only it is illustrated with the division of above-mentioned each functional module, in practical application, it can as needed and by above-mentioned functions distribute and be completed by different functional modules, the internal structure of device is divided into different functional modules, to complete all or part of function described above.The specific work process of the device of foregoing description, may be referred to the corresponding process in preceding method embodiment, will not be repeated here.

Finally it should be noted that：Various embodiments above is merely illustrative of the technical solution of the present invention, rather than its limitations；Although the present invention is described in detail with reference to foregoing embodiments, it will be understood by those within the art that：It can still modify to the technical scheme described in foregoing embodiments, or carry out equivalent substitution to which part or all technical characteristic；And these modifications or replacement, the essence of appropriate technical solution is departed from the scope of various embodiments of the present invention technical scheme.

Claims

Claims

1st, a kind of system of selection of access point, it is characterised in that including：

Centralized Controller receives the status information of at least one access point AP transmissions, and the status information includes sending the AP of status information load information；

The Centralized Controller is chosen for work station according to the status information of at least one AP

STA provides at least one target AP of wireless service;

The Centralized Controller sends the response message for carrying response policy at least one described AP, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, other AP are not responding to the detection frame of the STA broadcast, so that the STA selects to service AP from least one target AP.

2nd, the method according to claim 1, it is characterised in that the quality information of channel between AP and the STA of the status information also including sending the status information；

The Centralized Controller is chosen at least one target AP that STA provides wireless service according to the status information of at least one AP, including：

The Centralized Controller is chosen at least one target AP that the STA provides wireless service according to the quality information of channel between the load information and each AP and the STA of each AP at least one described AP.

3rd, method according to claim 1 or 2, it is characterized in that, the status information is that at least one described AP is sent to the Centralized Controller after the detection frame of the STA broadcast is received, or at least one described AP periodicity or event triggering property are sent to the Centralized Controller.

4th, the method according to any one of claims 1 to 3, it is characterised in that the Centralized Controller is chosen for after at least one target AP that STA provides wireless service according to the status information of at least one AP, in addition to：

If at least one target AP does not include current service AP, and the Centralized Controller determines that the STA does not switch service AP in preparatory condition, then send and indicate that message indicates that the current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

5th, the method according to any one of Claims 1-4, it is characterised in that the Centralized Controller is received after the status information of at least one AP transmissions, in addition to：

The Centralized Controller determines whether to be stored with the list item of the STA, if so, then according to institute State the list item of STA described in state information updating；

If nothing, the list item of the STA is generated according to the status information；The list item of the STA is used for the status information for storing the correspondence STA received；

The Centralized Controller is chosen at least one target AP that STA provides wireless service according to the status information of at least one AP, including：

The status information that the Centralized Controller is stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.

6th, the method according to any one of claim 2 to 5, it is characterised in that the Centralized Controller is chosen for the target AP that STA provides wireless service according to the status information of at least one AP, including：

The Centralized Controller according at least one described AP between each AP and the STA channel quality information and pre-determined threshold, determine AP to be selected;

The Centralized Controller chooses at least one minimum AP of load as at least one target AP in the AP to be selected.

7th, the method according to any one of claim 2 to 6, it is characterized in that, the quality information of the channel includes the signal strength information of channel between each AP to the STA at least one described AP, or, the up modulation that each AP is counted at least one described AP and coding strategy MCS bag distributed intelligences.

8th, a kind of system of selection of access point, it is characterised in that including：

Access point AP receives the response message for carrying response policy that Centralized Controller is sent, the response message is that the Centralized Controller is sent to the AP after the status information that the AP is sent is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to the detection frame of the STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；

If the AP has been received by the detection frame of the STA broadcast, then whether at least one target AP includes the AP according to being determined the response policy, if so, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame. 9th, method according to claim 8, it is characterised in that the quality information of channel between AP and the STA of the status information also including sending the status information；

At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, including：

At least one target AP is the Centralized Controller according to each at least one described AP

The quality information of channel is what the STA chose between AP load information and each AP and the STA.

10th, method according to claim 8 or claim 9, it is characterised in that the AP is received before the response message for carrying response policy that Centralized Controller is sent, in addition to：

The AP sends the status information to the Centralized Controller after the detection frame of the STA broadcast is received；

Or, the AP is periodically or event triggering property sends the status information to the Centralized Controller.

11st, the method according to any one of claim 8 to 10, it is characterised in that also include：The AP receives the instruction message that the Centralized Controller is sent, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message is that the Centralized Controller determines that at least one target AP does not include current service AP, and determines that the STA does not switch what is sent during service AP in preparatory condition.

12nd, the method according to any one of claim 8 to 11, it is characterised in that the AP is received after the response message for carrying response policy that Centralized Controller is sent, in addition to：

The AP sets up or updated the response policy of the STA according to the response policy.

13rd, method according to claim 12, it is characterised in that the AP is received before the response message for carrying response policy that Centralized Controller is sent, in addition to：

The AP receives the detection frame of the STA broadcast；

The AP determines whether to be stored with the response policy of the STA, if nothing, the status information of the AP is then sent to the Centralized Controller, to cause the Centralized Controller to obtain the status information of the AP, it is determined that at least one target AP, and send the response message for carrying the response policy.

14th, a kind of Centralized Controller, it is characterised in that including：

First receiving module, the status information for receiving at least one access point AP transmissions is described Status information includes sending the AP of status information load information；

Processing module, the status information for being received according to first receiving module is chosen at least one target AP that work station STA provides wireless service;

Sending module, the response message for carrying response policy is sent at least one described AP at least one target AP according to processing module selection, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, other AP are not responding to the detection frame of the STA broadcast, so that the STA selects to service AP from least one target AP.

15th, Centralized Controller according to claim 14, it is characterised in that the processing module is additionally operable to：If between AP and the STA of the status information also including sending the status information during quality information of channel, according to the quality information of channel between the load information and each AP and the STA of each AP at least one described AP, at least one target AP that the STA provides wireless service is chosen for.

16th, the Centralized Controller according to claims 14 or 15, it is characterised in that the processing module is additionally operable to：In the status information according at least one AP, it is chosen for after at least one target AP that STA provides wireless service, if at least one target AP does not include current service AP, and determine that the STA does not switch service AP in preparatory condition, then send and indicate that message indicates that the current service AP sends disassociation message to the STA, detection frame is re-broadcast to trigger the STA.

17th, the Centralized Controller according to any one of claim 14 to 16, it is characterised in that the processing module is additionally operable to：After the status information for receiving at least one AP transmissions, it is determined whether the list item for the STA that is stored with, if so, then according to the state information updating STA list item, if nothing, the list item of the STA is generated according to the status information；The list item of the STA is used for the status information for storing the correspondence STA received；The status information stored according to the list item of the STA, is chosen at least one target AP that the STA provides wireless service.

18th, a kind of access point apparatus, it is characterised in that including：

Second receiving module, the response message for carrying response policy for receiving Centralized Controller transmission, the response message is that the Centralized Controller is sent to the AP after the status information of access point AP transmissions is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to institute State the detection frame of STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；

Respond module, if the detection frame for having been received by the STA broadcast, whether at least one target AP includes the AP according to being determined the response policy, if, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

19th, access point apparatus according to claim 18, it is characterised in that the quality information of channel between AP and the STA of the status information also including sending the status information；At least one target AP is that the Centralized Controller is chosen according to the status information that at least one AP is sent, including：

At least one target AP is that the quality information of channel between the load information of each AP in the Centralized Controller at least one AP according to and each AP and the STA is chosen for the STA.

20th, the access point apparatus according to claim 18 or 19, it is characterised in that the respond module is additionally operable to：

Receive the instruction message that the Centralized Controller is sent, disassociation message is sent to the STA, detection frame is re-broadcast to trigger the STA, the instruction message is that the Centralized Controller determines that at least one target AP does not include current service AP, and determines that the STA does not switch what is sent during service AP in preparatory condition.

21st, a kind of Centralized Controller, it is characterised in that including receiver, processor and memory, wherein：

The receiver is used for the status information for receiving at least one access point AP transmissions, and the status information includes sending the AP of status information load information；

The memory storage has batch processing code, and the processor calls described program code, to perform following operation：According to the status information of at least one AP, it is chosen at least one target AP that work station STA provides wireless service, the response message for carrying response policy is sent at least one described AP, the response policy is used for the detection frame for indicating that at least one target AP responds the STA broadcast, and other AP are not responding to the detection frame of the STA broadcast；So that the STA selects to service AP from least one target AP. The memory is additionally operable to store the response policy.

22nd, the Centralized Controller according to claim 21, it is characterised in that the quality information of channel between AP and the STA of the status information also including sending the status information.

23rd, a kind of access point apparatus, it is characterised in that including：

Receiver, the response message for carrying response policy for receiving Centralized Controller transmission, the response message is that the Centralized Controller is sent to the AP after the status information of access point AP transmissions is received, the response policy is used to indicate to receive the detection frame of at least one target AP responsive operations station STA broadcast in the AP of the response message, and other AP are not responding to the detection frame of the STA broadcast；At least one target AP is that the status information that the Centralized Controller is sent according at least one AP is chosen for the STA, and the status information includes sending the AP of status information load information；

Processor, if the detection frame for having been received by the STA broadcast, whether at least one target AP includes the AP according to being determined the response policy, if, the detection frame is responded, so that the STA selects to service AP from least one target AP;If it is not, being not responding to the detection frame.

24th, the access point apparatus according to claim 23, it is characterised in that the quality information of channel between AP and the STA of the status information also including sending the status information.