CN111615173A

CN111615173A - Roaming control method, device, wireless equipment and storage medium

Info

Publication number: CN111615173A
Application number: CN202010254446.2A
Authority: CN
Inventors: 黄泽淳; 程文强
Original assignee: TP Link Technologies Co Ltd
Current assignee: Chengdu Lianzhou International Technology Co ltd
Priority date: 2020-04-02
Filing date: 2020-04-02
Publication date: 2020-09-01
Anticipated expiration: 2040-04-02
Also published as: CN111615173B

Abstract

The invention discloses a roaming control method, a roaming control device, wireless equipment and a storage medium, wherein the method comprises the following steps: acquiring the uplink signal intensity of a client to be roamed; inquiring a first trigger probability corresponding to the uplink signal strength from a first table; triggering the current wireless AP to send an RRM request to a client to be roamed according to the first triggering probability; when an RRM request is sent to a client to be roamed and a reply message returned by the client to be roamed is received, selecting one candidate BSSID as a target BSSID; when the target BSSID is not the current BSSID, indicating the client to be roamed to the target BSSID, and detecting the roaming state of the client to be roamed; when the roaming success of the client to be roamed is detected, increasing a first trigger probability corresponding to the uplink signal intensity in a first table; and when the roaming failure of the client to be roamed is detected, reducing the first trigger probability corresponding to the uplink signal strength in the first table. The invention can reduce the waste of network resources and improve the success rate of roaming.

Description

Roaming control method, device, wireless equipment and storage medium

Technical Field

The present invention relates to the field of roaming technologies, and in particular, to a roaming control method and apparatus, a wireless device, and a storage medium.

Background

Roaming refers to the process of switching a client from one Basic service point to another Basic service point, wherein, for a wireless access point capable of dual-band operation, the access point has 2 Basic service points and 2 Basic service identities (i.e. Basic service set Identifier, BSSID); for a wireless access point operating on a single frequency, the access point has 1 basic service point and 1 basic service identifier. Because the power of the wireless access point is limited and the coverage area is limited, in the same network system, a plurality of wireless access points are usually needed to ensure the coverage area of the network, and when a certain client leaves the network coverage area of the currently associated basic service point, roaming handover is often needed to be performed, and the client is handed over to re-associate with other basic service points for connection.

An existing roaming control strategy is that a wireless access point periodically monitors an RSSI value of a client, compares the RSSI value with a signal strength threshold, when the monitored RSSI value is smaller than the signal strength threshold, the wireless access point sends an RRM request to the client (that is, triggers the wireless access point to send an 802.11k message to the client), after receiving the RRM request, the client starts to query RSSI values corresponding to other alternative basic service points in a network topology, returns the RSSI values corresponding to the alternative basic service points to a currently associated wireless access point, and determines a target basic service point according to all the RSSI values, thereby controlling the client to roam to the target wireless AP.

However, the inventor of the present application finds that, when performing roaming control of a client according to a scheme in the prior art, the client itself also has a related roaming policy, and different roaming policies of the client itself are different, which is mainly embodied in that a packet sent by the client to a wireless access point is conditionally received by the client. However, in the roaming control scheme in the prior art, only the roaming control policy of the wireless access point to the client is considered, and the acceptance of the client to the related message is not considered, so that the situation that the wireless access point repeatedly sends an unacceptable message to the client exists, which may cause the waste of network resources, and may also affect the roaming of the client to other alternative basic service points, thereby affecting the success rate of roaming.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a roaming control method, apparatus, wireless device and storage medium, which can reduce the waste of network resources and improve the roaming success rate of a client when controlling the roaming of the client.

In order to solve the above technical problem, in a first aspect, the present invention provides a roaming control method, including:

acquiring the uplink signal intensity of a client to be roamed relative to a current associated wireless AP;

inquiring a first trigger probability corresponding to the uplink signal strength from a first table associated with the client to be roamed;

triggering the current wireless AP to send an RRM request to the client to be roamed according to the first triggering probability;

when an RRM request is sent to the client to be roamed and a reply message returned by the client to be roamed is received, selecting one candidate BSSID as a target BSSID according to each candidate BSSID of the client to be roamed contained in the reply message and the downlink signal strength from each candidate BSSID to the client to be roamed;

when the target BSSID is not the current BSSID associated with the client to be roamed, indicating the client to be roamed to the target BSSID, and detecting the roaming state of the client to be roamed; and the number of the first and second electrodes,

when the roaming success of the client to be roamed is detected, increasing the first trigger probability corresponding to the uplink signal strength in the first table; and when the roaming failure of the client to be roamed is detected, reducing the first trigger probability corresponding to the uplink signal strength in the first table.

Further, the selecting one of the candidate BSSIDs as the target BSSID specifically includes:

acquiring the throughput corresponding to the downlink signal strength according to the pre-acquired prior data corresponding to each candidate BSSID;

calculating a reference index for each of the candidate BSSIDs based on each of the throughputs;

determining the target BSSID according to the reference index of each candidate BSSID.

Further, the calculating a reference index for each candidate BSSID according to each throughput specifically includes:

acquiring the current downlink signal strength from the current wireless AP to the client to be roamed, and calculating the downlink signal strength difference between each downlink signal strength and the current downlink signal strength;

respectively forming an index combination by the current downlink signal strength and each downlink signal strength difference value, and inquiring a second trigger probability corresponding to each index combination from a second table associated with the client to be roamed;

calculating a reference index for each of the candidate BSSIDs based on the second trigger probability and the throughput corresponding to each of the index combinations;

then, after the detecting the roaming state of the client to be roamed, the method further includes:

when the roaming success of the client to be roamed is detected, increasing a second trigger probability corresponding to each index combination in the second table; and when the roaming failure of the client to be roamed is detected, reducing the second trigger probability corresponding to each index combination in the second table.

Further, the method calculates a reference index for each of the candidate BSSIDs by the following formula:

I_i＝P(RCPI_curr，ΔRCPI_i)*Thr(RCPI_i)；

wherein, I_iA reference index for the ith said candidate BSSID; RCPI_currThe current downlink signal strength is obtained; RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; p (RCPI)_curr，ΔRCPI_i) Is an index combination (RCPI)_curr，ΔRCPI_i) A corresponding second trigger probability; thr (RCPI)_i) For the ith candidate BSSID, the downlink signal strength is RCPI_iThe throughput of time.

Further, when it is detected that the roaming of the client to be roamed is successful, increasing the second trigger probability corresponding to each index combination in the second table specifically includes:

when the roaming success of the client to be roamed is detected, updating a second trigger probability corresponding to each index combination in the second table according to the following formula:

P′(RCPI_curr，ΔRCPI_i)＝×P(RCPI_curr，ΔRCPI_i)+1-

wherein, RCPI_currFor the current downlink signal strength, RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; p (RCPI)_curr，ΔRCPI_i) In combination with an index (RCPI)_curr，ΔRCPI_i) A corresponding second trigger probability before updating; p' (RCPI)_curr，ΔRCPI_i) In combination with an index (RCPI)_curr，ΔRCPI_i) A corresponding updated second trigger probability; is a first step length parameter less than 1.

Further, when it is detected that the roaming of the client to be roamed fails, reducing a second trigger probability corresponding to each index combination in the second table specifically includes:

when the roaming failure of the client to be roamed is detected, calculating a second step length parameter of a second trigger probability corresponding to each index combination according to the following formula:

updating a second trigger probability corresponding to each index combination in the second table according to the following formula:

P′(RCPI_curr，ΔRCPI_i)＝′(RCPI_curr，ΔRCPI_i)×P(RCPI_curr，ΔRCPI_i)

wherein, RCPI_currThe current downlink signal strength is obtained; RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; RCPI_targetThe downlink signal strength corresponding to the target BSSID is obtained; delta RCPI_targetFor the downlink signal strength RCPI_targetAnd the current downlink signal strength RCPI_currThe difference between the downlink signal strengths, α is a preset control coefficient, P (RCPI)_curr，ΔRCPI_i) In combination with an index (RCPI)_curr，ΔRCPI_i) A corresponding second trigger probability before updating; ' (RCPI)_curr，ΔRCPI_i) Is the second trigger probability P (RCPI)_curr，ΔRCPI_i) A corresponding second step size parameter; p' (RCPI)_curr，ΔRCPI_i) In combination with an index (RCPI)_curr，ΔRCPI_i) A corresponding updated second trigger probability.

Further, the determining the target BSSID according to the reference indicator of each candidate BSSID specifically includes:

when all the reference indexes of the candidate BSSIDs have reference indexes meeting a first preset condition, determining an optimal reference index from all the reference indexes meeting the first preset condition; determining candidate BSSIDs corresponding to the optimal reference indexes as the target BSSIDs;

when the reference indexes of all the candidate BSSIDs do not have the reference indexes meeting a first preset condition, determining the current BSSID associated with the client to be roamed as the target BSSID.

Further, the first preset condition includes:

I_i≥d*Thr_curr

wherein, I_iIs a reference index of the ith candidate BSSID, d is a preset value which is more than 1, Thr_currObtaining the throughput from the current BSSID for the client to be roamed.

Further, when it is detected that the roaming of the client to be roamed is successful, increasing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

when the roaming success of the client to be roamed is detected, updating the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula:

P′(RSSI)＝×P(RSSI)+1-

wherein, RSSI is the uplink signal strength, and P' (RSSI) is an updated first trigger probability corresponding to the uplink signal strength RSSI; a first step size parameter less than 1; p (RSSI) is a first trigger probability before update corresponding to the uplink signal strength RSSI.

Further, when it is detected that the roaming of the client to be roamed fails, reducing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

when the roaming failure of the client to be roamed is detected, updating the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula:

P′(RSSI)＝×P(RSSI)

Further, after the triggering the current wireless AP to send an RRM request to the client to be roamed with the first trigger probability, the method further includes:

when an RRM request is sent to the client to be roamed and a reply packet returned by the client to be roamed is not received, updating the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula:

P′(RSSI)＝×P(RSSI)

Further, the method further comprises:

when the client to be roamed is monitored to actively roam, increasing the first trigger probability corresponding to the uplink signal strength in the first table; and the number of the first and second electrodes,

calculating a third step length parameter of all the second trigger probabilities in the second table;

and updating all the second probabilities in the second table according to the third step length parameter.

Further, when it is monitored that the to-be-roamed client performs active roaming, increasing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

when the client to be roamed is monitored to actively roam, updating the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula:

P′(RSSI)＝×P(RSSI)+1-

Further, the method further comprises:

when an RRM request is sent to the client to be roamed and a reply message returned by the client to be roamed is received, updating the value of a preset compensation parameter according to the following formula:

offset＝b×offset₀+(1-b)×(RSSI-RCPI_curr)

wherein the offset is the compensation parameter after the value is updated; b is a preset value less than 1; offset₀The compensation parameter before the value is updated; RSSI is the uplink signal strength; RCPI_currThe current downlink signal strength is obtained;

then, the method calculates a third step length parameter for all of the second trigger probabilities in the second table by:

wherein the content of the first and second substances,₃is the third step length parameter, α is the preset control coefficient, RSSI_table1When the active roaming is performed for the client to be roamed, the uplink signal strength in the first table; RCPI_currAnd the current downlink signal strength is obtained.

Further, the updating all the second probabilities in the second table according to the third step length parameter specifically includes:

updating all of the second probabilities in the second table according to the following formula:

P′(RCPI，ΔRCPI)＝₃×P(RCPI，ΔRCPI)

wherein the content of the first and second substances,₃is the third step length parameter; p (RCPI, Δ RCPI) is the second trigger probability before updating corresponding to the index combination (RCPI, Δ RCPI); p' (RCPI, Δ RCPI) is the updated second trigger probability corresponding to the index combination (RCPI, Δ RCPI).

Further, the triggering, by the first trigger probability, the current wireless AP to send an RRM request to the client to be roamed specifically includes:

randomly generating a random number in the [ O, 1] interval;

and when the random number is not greater than the first trigger probability, triggering the current wireless AP to send an RRM request to the client to be roamed.

Further, after the selecting one of the candidate BSSIDs as the target BSSID, the method further includes:

when the target BSSID is the current BSSID, triggering the client to be roamed to be in a suspended state; the current wireless AP forbids to send an RRM request to a client to be roamed in a suspended state; and the current wireless AP initializes the first-associated client to be roamed into a non-suspended state.

Further, the acquiring the uplink signal strength of the to-be-roamed client relative to the currently associated current wireless AP specifically includes:

s101, inquiring the first uplink signal strength of the client to be roamed relative to the current wireless AP;

s102, when the fact that the client to be roamed is in the suspended state and the strength of the first uplink signal meets a second preset condition is detected, returning to the step S101 again;

s103, when the fact that the client to be roamed is in the suspended state and the strength of the first uplink signal does not meet a second preset condition is detected, the suspended state of the client to be roamed is released, and the step S101 is returned again;

and S104, when the client to be roamed is detected to be in a non-suspended state, taking the first uplink signal strength inquired newly as the uplink signal strength.

Further, after the triggering the to-be-roamed client to be in a suspended state when the target BSSID is the current wireless AP, the method further includes:

updating an uplink signal strength reference value according to the uplink signal strength;

then, the second preset condition is:

a1≤RSSI₁-tempRSSI≤a2

wherein the RSSI₁The first uplink signal strength; a1 is a first preset value; a2 is a second preset value; and the tempRSSI is the uplink signal strength reference value.

In order to solve the corresponding technical problem, in a second aspect, the present invention provides a roaming control apparatus, including:

the acquisition module is used for acquiring the uplink signal intensity of the client to be roamed relative to the current associated wireless AP;

the query module is used for querying a first trigger probability corresponding to the uplink signal strength from a first table associated with the client to be roamed;

a triggering module, configured to trigger, with the first triggering probability, the current wireless AP to send an RRM request to the client to be roamed;

a selecting module, configured to, when an RRM request is sent to the client to be roamed and a reply message returned by the client to be roamed is received, select one of the candidate BSSIDs as a target BSSID according to each candidate BSSID of the client to be roamed and downlink signal strength from each candidate BSSID to the client to be roamed, where the candidate BSSID is included in the reply message;

an indicating module, configured to indicate, when the target BSSID is not the current BSSID associated with the client to be roamed, that the client to be roamed roams to the target BSSID, and detect a roaming state of the client to be roamed; and the number of the first and second electrodes,

a first updating module, configured to increase the first trigger probability corresponding to the uplink signal strength in the first table when it is detected that the roaming of the client to be roamed is successful; and when the roaming failure of the client to be roamed is detected, reducing the first trigger probability corresponding to the uplink signal strength in the first table.

In order to solve the corresponding technical problem, in a third aspect, the present invention provides a wireless device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the roaming control method as set forth in any one of the above provided first aspects.

In order to solve the corresponding technical problem, in a fourth aspect, the present invention provides a computer-readable storage medium, where the computer-readable storage medium includes a stored computer program, and when the computer program runs, the apparatus where the computer-readable storage medium is located is controlled to execute the roaming control method according to any one of the above-mentioned first aspects.

Drawings

Fig. 1 is a flowchart illustrating a roaming control method according to a preferred embodiment of the present invention;

figure 2 is a schematic flow diagram of a preferred embodiment of selecting a target BSSID;

FIG. 3 is a schematic flow chart of a preferred embodiment of step S420 in FIG. 2;

FIG. 4 is a schematic flow chart of a preferred embodiment of step S100 in FIG. 1;

FIG. 5 is a flow chart illustrating a roaming control method according to another preferred embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a preferred embodiment of a roaming control device provided in the present invention;

fig. 7 is a schematic structural diagram of a preferred embodiment of a wireless device provided in the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The network topology is generally composed of a plurality of wireless access points and a plurality of clients, and each wireless access point can be connected with a plurality of clients. Any wireless access point in the network topology can execute the roaming control method provided by the invention to perform roaming control on the client connected with the wireless access point. When each wireless access point performs roaming control on each client, the roaming control method provided by the invention is applied, and the roaming control method provided by the invention can be executed by the wireless access point for each client.

Specifically, an embodiment of the present invention provides a roaming control method, please refer to fig. 1, where fig. 1 is a schematic flow chart of a preferred embodiment of a roaming control method according to the present invention; specifically, the method comprises the following steps:

s100, acquiring the uplink signal intensity of the client to be roamed relative to the currently associated current wireless AP.

S200, inquiring a first trigger probability corresponding to the uplink signal strength from a first table associated with the client to be roamed.

The first table is a table describing a correspondence relationship between the uplink signal strength RSSI of the client and the first trigger probability; optionally, the wireless AP may construct different first tables for different clients, or may collect and store the relevant information of each client in one first table, as long as the information corresponding to each client can be queried. For each obtained uplink signal strength RSSI, if the RSSI does not exist in the first table associated with the client to be roamed, the RSSI is added to the corresponding first table, and the first trigger probability corresponding to the RSSI is initialized, for example, in step S1OO, the uplink signal strength is obtained to be 30db, no relevant entry with RSSI equal to 30 exists in the corresponding first table, RSSI equal to 30 is added to the first table, and the corresponding first trigger probability p (RSSI) is initialized to be 0.5, as shown in table 1 below:

TABLE 1 first Table

RSSI/db	P(RSSI)
		40	0.65
30	0.5

In a preferred embodiment, in order to facilitate the management of the information of each client by the wireless AP, the wireless AP establishes a first table for each accessed client.

In another preferred embodiment, since the difference of the roaming policies of different clients is generally the difference of the roaming policies of different vendors (for example, different mobile phone vendors), the first table may be established for different vendors, so as to reduce the occupation of the storage space. When the first trigger probability needs to be inquired, the first table corresponding to the equipment merchant of the client to be roamed is the first table associated with the client to be roamed. In an optional embodiment, for a first-time accessed client, the wireless AP first acquires an MAC address of the client, and acquires an equipment provider of the first-time accessed client through an IEEE database according to the MAC address, and initializes and establishes different first tables for different equipment providers; for a client which is not accessed for the first time, after the wireless AP directly learns the corresponding equipment provider according to the MAC address of the client, the wireless AP can directly call the first table corresponding to the equipment provider to determine the first table associated with the client.

Furthermore, many clients on the market can support multi-band operation, for example, support operation in the 2.4GHz band and the 5GHz band, so the first table can be further established for each band. For example, if the wireless AP establishes the first tables for each accessed client, two first tables are established and maintained for each client that can operate in the 2.4GHz band and the 5GHz band; for another example, if the first tables are created for different vendors, two first tables are created for each vendor. When step S200 is executed to query the first trigger probability, the first table under the current communication frequency band needs to be selected from the first tables associated with the client to be roamed according to the current communication frequency band between the client to be roamed and the currently associated basic service point.

It should be noted that the rrm (radio Resource measurement) request corresponds to an 801.11k message in the current communication protocol, and is used to measure the Resource usage in the wireless network. The wireless AP sends an RRM request to the client, the client measures the wireless network after receiving the RRM request, and stores and returns a measurement result to the wireless AP which carries out the RRM request, the measurement result comprises downlink signal strength (RCPI) from each basic service point to the client, each basic service point is indicated by the basic service identifier, and the measurement result comprises the corresponding relation of (BSSID, RCPI). The first trigger probability is a probability of triggering the wireless AP to send the RRM request to the client, and the first trigger probability in the first table corresponds to the uplink signal strength, that is, represents a probability of sending the RRM request to the client by the wireless AP at a certain uplink signal strength.

And S300, triggering the current wireless AP to send an RRM request to the client to be roamed according to the first triggering probability.

Specifically, the uplink signal strength RSSI obtained in step S100_currThe corresponding first trigger probability is P (RSSI)_curr) Then there is P (RSSI)_curr) Probability the current wireless AP sends R to the client to be roamedRM request, with 1-P (RSSI)_curr) Probability of the current wireless AP will not send an RRM request to the client to roam. Preferably, if the current wireless AP does not send the RRM request to the to-be-roamed client, the process returns to step S100 after a certain time t 1. The time t1 may be set according to actual needs, for example, t1 equals 1 second.

S400, when an RRM request is sent to the client to be roamed and a reply message returned by the client to be roamed is received, selecting one candidate BSSID as a target BSSID according to each candidate BSSID of the client to be roamed and downlink signal strength RCPI from each candidate BSSID to the client to be roamed, wherein the candidate BSSID is contained in the reply message.

In step S400, a manner of deciding a roaming target may be set according to actual needs to select a target BSSID. Optionally, the target BSSID may be directly selected according to the downlink signal strength corresponding to each BSSID, for example, the BSSID corresponding to the maximum downlink signal strength is selected as the target BSSID; optionally, other parameters may be obtained by querying or calculating according to the downlink signal strength corresponding to each BSSID, and the target BSSID is selected in combination with the downlink signal strength and the other parameters, where the other parameters may be throughput, channel utilization, and the like in the network environment.

S500, when the target BSSID is not the current BSSID associated with the client to be roamed, indicating the client to be roamed to the target BSSID, and detecting the roaming state of the client to be roamed.

Specifically, after the target BSSID is selected, when the target BSSID is not the current BSSID, it indicates that other BSSIDs can provide better network performance for the client to be roamed, and the current wireless AP indicates that the client to be roamed roams to the target BSSID, and specifically, in the current communication protocol, the current wireless AP sends a btm (bss transition management) request to the client to be roamed, so as to suggest that the client to be roamed to the target BSSID. Further, the roaming state of the client to be roamed is detected, and whether the client to be roamed successfully roams to the target BSSID is known.

It should be noted that, assuming that there are 10 wireless APs in the network topology, which are respectively the wireless AP 1-the wireless AP10, after the client connects to any one of the wireless APs, for example, the client connects to the wireless AP1, the wireless AP1 sends a notification to other wireless APs (the wireless AP 2-the wireless AP10) in the network topology, and notifies the other wireless APs that the client has connected to the wireless AP 1. Therefore, when the wireless AP where the target BSSID is located (the wireless AP in dual-band operation has 2 BSSIDs) is received to notify that the client to be roamed is connected to the target BSSID, it can be known that the client to be roamed is successful.

S600, when the roaming success of the client to be roamed is detected, increasing the first trigger probability corresponding to the uplink signal strength in the first table; and when the roaming failure of the client to be roamed is detected, reducing the first trigger probability corresponding to the uplink signal strength in the first table.

In step S600, the first trigger probability is adjusted according to the roaming status of the to-be-roamed client, and the uplink signal strength RSSI of the successful roaming is increased_currCorresponding first trigger probability P (RSSI)_curr) And decrease the RSSI of the uplink signal strength when the roaming fails_currCorresponding first trigger probability P (RSSI)_curr). It should be noted that the probability value must be less than or equal to 1, which is a well-known mathematical characteristic of the skilled person, so that if the first trigger probability before increasing is equal to 1, the skilled person can foresee that the first trigger probability value after increasing can only be equal to 1, i.e. O is increased.

The roaming control method provided by the invention can consider the response condition of the client to the roaming control of the wireless AP, and update the first trigger probability in the scenes of successful roaming and failed roaming.

Preferably, as shown in fig. 2, the selecting one of the candidate BSSIDs as the target BSSID specifically includes:

s410, acquiring the throughput corresponding to the downlink signal strength according to the pre-acquired prior data corresponding to each candidate BSSID;

s420, calculating a reference index of each candidate BSSID according to each throughput;

s430, determining the target BSSID according to the reference index of each candidate BSSID.

Specifically, the prior data of each basic service point includes a corresponding relationship between downlink signal strength and throughput, and the product data of each wireless AP may be tested in advance to obtain the product data. In this embodiment, a reference index is calculated in consideration of the throughput provided by each candidate BSSID, and a target BSSID is selected based on the reference index.

Preferably, as shown in fig. 3, step S420 specifically includes the following steps S421 to S423:

s421, obtaining the current downlink signal strength RCPI from the current wireless AP to the client to be roamed_currAnd calculating each downlink signal strength RCPI and the current downlink signal strength RCPI_currThe downstream signal strength difference between △ RCPI.

Specifically, assuming that in the network topology, the client to be roamed has 20 candidate BSSIDs, RCPI from the ith candidate BSSID to the client to be roamed_iComputing △ RCPI_i＝RCPI_i-RCPI_currAnd △ RCPI are obtained by sequential calculation₁～△RCPI₂₀There are a total of 20 downstream signal strength differences △ RCPI.

S422, respectively combining the current downlink signal strength with each downlink signal strength difference to form an index combination, and querying a second trigger probability corresponding to each index combination from a second table associated with the client to be roamed.

The second table records second trigger probabilities corresponding to different index combinations. The second table is established in a similar manner to the first table, for example, the second table may also be established by summarizing each client, establishing for different clients and different operating frequency bands, or establishing for different device vendors of different clients and different operating frequency bands. Likewise, for the first added index combination, the corresponding second trigger probability may be set to a default value, for example, O.5. The second table is shown in table 2 below:

TABLE 2 second Table

S423, calculating a reference index for each candidate BSSID according to the second trigger probability and the throughput corresponding to each index combination.

And calculating the reference index of each candidate BSSID according to the corresponding second trigger probability and throughput, wherein a specific calculation formula can be set according to an actually set roaming strategy. For example, corresponding to the ith BSSID, the corresponding index combination is (RCPI)_curr，△RCPI_i) Then look-up and index combination (RCPI) from the second table_curr，△RCPI_i) Corresponding second trigger probability P (RCPI)_curr，△RCPI_i) (ii) a According to the prior data, obtaining the downlink signal strength RCPI of the ith BSSID_iThroughput at time T is Thr (RCPI)_i) (ii) a The reference index corresponding to the ith BSSID is determined according to a second trigger probability P (RCPI)_curr，△RCPI_i) And throughput Thr (RCPI)_i) And (6) calculating.

As can be seen from the above explanation, in this embodiment, the second trigger probability affects to some extent whether each BSSID is the target BSSID, and the BTM request indicates that the client to roam roams to the target BSSID, so the second trigger probability affects the probability of triggering the current wireless AP to send a different BTM request.

In this embodiment, the acceptance of the client to the roaming indication (BTM request) of the wireless AP is considered, and in the scenarios of successful roaming and failed roaming, the second trigger probability is further updated, and since the selection of the target BSSID is related to the second trigger probability, which affects the sending probability of different BTM requests, the second trigger probability is updated and adjusted, so that the repeated sending of the BTM request which is not accepted to the client by the wireless AP can be reduced, and the waste of network resources is further reduced; meanwhile, the wireless AP is driven to indicate the target BSSID with higher roaming success rate to the client, so that the roaming success rate is further improved.

It should be noted that, assuming that 45 entries { ((RCPI, &ttttttranslation = Δ "&ttt &/t &tttrcpi) in the second table, P (RCPI, &ttttranslation &" Δ &ltt/t &tttrcpi) } in the second table, the 45 entries include entries { ((RCPI, &ttt/t &rcpi) corresponding to 20 candidate BSSIDs_curr，△RCPI_i)，P(RCPI_curr，△RCPI_i) An update of the second trigger probability of the second table here refers to entries corresponding to the 20 candidate BSSIDs { ((RCPI)_curr，△RCPI_i)，P(RCPI_curr，△RCPI_i) The second trigger probability of the remaining 25 entries is not updated.

Preferably, the method calculates a reference index for each of the candidate BSSIDs by the following formula:

I_i＝P(RCPI_curr，ΔRCPI_i)*Thr(RCPI_i) (1)

In this embodiment, a way of obtaining the reference index based on the second trigger probability and the throughput calculation is provided. A person skilled in the art can combine other network environment parameters to obtain a more comprehensive reference index based on the above formula (1), and the corresponding improvement is also within the protection scope of the embodiment.

Preferably, when it is detected that the roaming of the client to be roamed is successful, increasing the second trigger probability corresponding to each index combination in the second table specifically includes:

P′(RCPI_curr，ΔRCPI_i)＝×P(RCPI_curr，ΔRCPI_i)+1- (2)

In this embodiment, an implementation is provided for updating the second trigger probability when roaming is successful. From the above equation (2), it can be obtained:

P′(RCPI_curr，ΔRCPI_i)-P(RCPI_curr，ΔRCPI_i)

＝×P(RCPI_curr，ΔRCPI_i)+1--P(RCPI_curr，ΔRCPI_i)

＝(-1)×{P(RCPI_curr，ΔRCPI_i)-1}

alternatively, ═ 0.95. Further, since-1 < 0, P (RCPI)_curr，ΔRCPI_i) -1. ltoreq.0, thus P' (RCPI)_curr，ΔRCPI_i)-P(RCPI_curr，ΔRCPI_i) Not less than 0, it can be seen that the above formula can be implemented at [ O, 1]]Increasing the second trigger probability within the range, without the probability value exceeding 1, is a mathematical property well known to the skilled person, as can be understood when P (RCPI)_curr，ΔRCPI_i) When the trigger probability is 1, O is increased for the second trigger probability to obtain P' (RCPI)_curr，ΔRCPI_i)＝1。

Preferably, when it is detected that the client to be roamed fails to roam, the reducing a second trigger probability corresponding to each index combination in the second table specifically includes:

P′(RCPI_curr，ΔRCPI_i)＝′(RCPI_curr，ΔRCPI_i)×P(RCPI_curr，ΔRCPI_i) (4)

In this embodiment, the second step length parameter obtained from equation (3) is smaller than 1, and substituting equation (4) can realize that the second trigger probability after updating is smaller than the second trigger probability before updating, thereby realizing that the second trigger probability in the corresponding entry of the second table is reduced when roaming fails.

Preferably, the determining the target BSSID according to the reference indicator of each candidate BSSID specifically includes:

In this embodiment, candidate BSSIDs that do not satisfy the first preset condition are filtered, and a candidate BSSID having the best reference index is selected from the filtered candidate BSSIDs as the target BSSID. If candidate BSSID meeting the first preset condition cannot be found, the client to be roamed is continuously associated with the current BSSID, after a certain time t2, the uplink signal strength of the client to be roamed and the current wireless AP is continuously acquired, and the roaming control method provided by the invention is continuously executed.

It should be noted that the first preset condition may be designed according to actual requirements, for example, the candidate BSSID with a relatively small number of associated clients needs to be selected, or the candidate BSSID with a channel utilization rate meeting a certain condition needs to be selected, or the candidate BSSID with a throughput meeting a certain condition needs to be selected, and so on.

Preferably, the first preset condition includes:

I_i≥d*Thr_curr(5)

In this embodiment, a candidate BSSID with throughput that meets a certain condition is considered to be selected, and a candidate BSSID with throughput that is higher than that of a current BSSID by a certain degree is selected through formula (5), so that network performance obtained after roaming handover of a to-be-roamed client is obviously improved. The client is prevented from needing frequent roaming switching.

For example, assume that the reference index is calculated in the following manner: i is_i＝P(RCPI_curr，ΔRCPI_i)*Thr(RCPI_i) Thr (RCPI)_i)/Thr_curr≥d/P(RCPI_curr，ΔRCPI_i) Even if P (RCPI)_curr，ΔRCPI_i) Taking the maximum value of 1, Thr (RCPI)_i) At least also better than Thr_currOf a certain amplitude, i.e. (d-P (RCPI)_curr，ΔRCPI_i))*Thr_curr. The size of d can be designed according to actual requirements, for example, d is 1.1, and after roaming is successful, the pending roaming client can increase at least 10% of the original throughput.

Preferably, when it is detected that the roaming of the client to be roamed is successful, the increasing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

P′(RSSI)＝×P(RSSI)+1- (6)

In this embodiment, an implementation is provided for updating the first trigger probability when roaming is successful. From the above equation (6), it can be obtained:

P′(RSSI)-P(RSSI)

＝×P(RSSI)+1--P(RSSI)

＝(-1)×{P(RSSI)-1}

alternatively, ═ 0.95. Further, since-1 < 0, P (RSSI) -1 ≦ 0, and therefore P '(RSSI) -P (RSSI) ≧ 0, it can be seen that the above equation (6) can achieve the effect of increasing the first trigger probability in the range of [ O, 1], and the probability value cannot exceed 1, which is a well-known mathematical property of the skilled person, and it can be understood that when P (RSSI) is 1, O is increased for the first trigger probability, and P' (RSSI) is obtained as 1.

Preferably, when it is detected that the roaming of the client to be roamed fails, the reducing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

P′(RSSI)＝×P(RSSI) (7)

In this embodiment, an implementation is provided for updating the first trigger probability when roaming fails. Those skilled in the art can obtain other updated formulas by considering other parameters on the basis of the above formula (7), and the corresponding modifications are also within the scope of the present embodiment.

Preferably, after the triggering the current wireless AP to send an RRM request to the client to be roamed with the first trigger probability, the method further includes:

P′(RSSI)＝×P(RSSI)

Specifically, when the current wireless AP sends the RRM request but does not receive the reply packet of the to-be-roamed client, it indicates that the to-be-roamed client has a low acceptance to the RRM request in the current network environment, and may be in the network environment or in a policy of itself without receiving the RRM request, or may receive the RRM request, but does not respond to the RRM request according to its roaming policy. In this embodiment, when the RRM request is sent to the to-be-roamed client and the reply packet is not received, the first trigger probability is also reduced, so as to further reduce the RRM request that is repeatedly sent and is not received by the client, further reduce the waste of network resources, and improve the roaming success rate.

Preferably, the method further comprises:

In this embodiment, updating the first trigger probability and the second trigger probability when the client performs active roaming is further considered. It is assumed that the network topology includes 10 wireless APs, which are wireless AP 1-wireless AP10. After the client connects to any one of the wireless APs, for example, the wireless AP1, the wireless AP1 sends a notification to other wireless APs (wireless AP2 to wireless AP10) in the network topology, and notifies the other wireless APs that the client is connected to the wireless AP 1. Therefore, if the to-be-roamed client performs active roaming and roams from the wireless AP1 to the wireless AP2, the wireless AP1 receives a notification of disconnection of the to-be-roamed client, and if the notification of association between the to-be-roamed client and the wireless AP2, which is sent by the wireless AP2, is received within a certain time, the wireless AP1 can know that the to-be-roamed client performs active roaming. Further, if the to-be-roamed client disconnects from the wireless AP1 and does not receive the notification that the to-be-roamed client is associated with the wireless AP of the network topology within the preset time window (which may be set to 3 seconds), the wireless AP1 may know that the to-be-roamed client disconnects from the network of the network topology.

It can be understood that, after the active roaming, the to-be-roamed client is already disassociated from the currently associated current wireless AP, and the updating of the first trigger probability here is to update the first trigger probability of the uplink signal strength before the last queried to-be-roamed client and the currently associated current wireless AP, which is recorded in the table.

Preferably, when it is monitored that the to-be-roamed client performs active roaming, increasing the first trigger probability corresponding to the uplink signal strength in the first table specifically includes:

P′(RSSI)＝×P(RSSI)+1-

In this embodiment, when the client to be roamed actively roams, the first trigger probability is increased and updated according to the above formula. It should be noted that the formula of the present embodiment corresponds to the formula (6), and the implementation of the principle of reducing the first trigger probability also corresponds thereto, so that details are not repeated herein.

Preferably, the method further comprises:

offset＝b×offset₀+(1-b)×(RSSI-RCPI_curr) (8)

wherein the content of the first and second substances,₃is the third step length parameter, α is the preset control coefficient, RSSI_tablelWhen the active roaming is performed for the client to be roamed, the uplink signal strength in the first table; RCPI_currAnd the current downlink signal strength is obtained.

After the client to be roamed actively roams, the current wireless AP cannot acquire the downlink signal strength RCPI from each BSSID to the client to be roamed, and in this embodiment, a special update mechanism is provided to update the second trigger probability. Specifically, the compensation parameters are continuously updated through a formula (8), and when the third step length parameters need to be calculated, each third step length parameter is calculated through a formula (9) so as to update the second trigger probability of each second table. Optionally, b is 0.95.

Preferably, the updating all the second probabilities in the second table according to the third step length parameter specifically includes:

P′(RCPI，ΔRCPI)＝₃×P(RCPI，ΔRCPI) (10)

In this embodiment, the updating of the second trigger probability is specifically realized by formula (10). Those skilled in the art can obtain other updated formulas by considering other parameters on the basis of the above formula (10), and the corresponding modifications are also within the scope of the present embodiment.

Preferably, the triggering, by the first trigger probability, the current wireless AP to send an RRM request to the client to be roamed specifically includes:

randomly generating a random number in the [ O, 1] interval;

In this embodiment, by generating a random number in the [ O, 1] interval and comparing the random number with the first trigger probability, it is implemented that the current wireless AP has the first trigger probability p (rssi) to send the RRM request, and has a probability of 1-p (rssi) to not send the RRM request to the to-be-roamed client.

Preferably, after the selecting one of the candidate BSSIDs as the target BSSID, the method further includes:

In this embodiment, the roaming control method provided by the present invention further sets the ue to be in a suspended state or a non-suspended state (or called "awake state"). Specifically, the wireless AP initializes a client connected for the first time to a non-suspended state, and subsequently, if the client is used as a client to be roamed and the target BSSID is the current BSSID, the client is set to the suspended state, so that the current wireless AP does not perform any action on the client to be roamed within a time interval t3, and the client to be roamed enters a state of waiting to be executed, which can improve the robustness of the roaming control method of the present invention. Optionally, after the client to be roamed is triggered to be in the suspended state, the process returns to step S100 after a time interval t3 is set, and t3 may set a specific size according to actual needs, for example, t3 is 5 seconds.

It should be noted that, when the wireless AP initializes, the corresponding thread is started according to actual needs so as to obtain and monitor corresponding information, for example, the thread for monitoring the association and disconnection states of each client is started in the background; and starting a thread which inquires the RSSI value of each associated client in a certain period and updates the RSSI value of each client, starting a monitoring thread for client active roaming and the like.

Preferably, as shown in fig. 4, the acquiring the uplink signal strength of the to-be-roamed client relative to the currently associated current wireless AP specifically includes:

In this embodiment, the current wireless AP queries the first uplink signal strength of the client to be roamed according to a certain polling mechanism, and if the client to be roamed is in the suspended state, it indicates that a target BSSID better than the current BSSID is not found in the last roaming control performed on the client to be roamed, and under the condition that the network environment does not change much, it is likely that the target BSSID better than the current BSSID cannot be found in the current roaming control. In order to reduce the number of times of unnecessary RRM request transmission and the subsequent selection process of the target BSSID, the algorithm performance is better, in this embodiment, only when the client to be roamed is in the non-suspended state, the first uplink signal strength which is newly queried is used as the basis for roaming control. It should be noted that, after the suspended state of the to-be-roamed client is released, the to-be-roamed client is in the non-suspended state. The second preset condition may be set according to a specific judgment criterion of the network environment, for example, the change of the network environment is judged according to the change of the uplink signal strength, or the channel utilization rate, throughput, and the like are used as the judgment criterion.

Preferably, after the triggering that the client to be roamed is in a suspended state when the target BSSID is the current wireless AP, the method further includes:

then, the second preset condition is:

a1≤RSSI₁-tempRSSI≤a2 (11)

wherein the RSSI₁Is the firstAn uplink signal strength; a1 is a first preset value; a2 is a second preset value; and the tempRSSI is the uplink signal strength reference value.

In order to know the network environment variation condition of the current roaming control compared to the network environment variation condition under the last roaming control, in this embodiment, the uplink signal strength of the last roaming control is used as the reference value of the uplink signal strength, and the relation (11) is used as the second preset condition to judge the variation condition of the network environment. The values of a1 and a2 can be set according to actual needs, for example, when a1 is-3 and a2 is 6, the above relation (11) becomes-3 ≦ RSSI₁-tempRSSI≤6。

It should be noted that the above preferred embodiments are only illustrative, and the roaming control method provided by the present invention is not limited to be implemented by the above embodiments, for example, the above preferred embodiments may be integrated with each other to form other preferred embodiments without conflict.

For ease of understanding, assuming that the client has 20 candidate BSSIDs in the network topology, a possible embodiment of a roaming control method provided by the present invention is briefly set forth below, as shown in fig. 5:

s1, initializing; and starting related threads in a background, wherein the related threads comprise a thread for monitoring association and disconnection of the client, a thread for setting the client to be in a suspended state or a non-suspended state, a thread for polling the RSSI of the client, a thread for monitoring the active roaming behavior of the client and the like.

S2, monitoring the association event of the client, setting the client to be in the association state, and creating or calling the corresponding first table and the second table. For the first-time associated client, preferably, the device provider is queried in the IEEE library according to the MAC address of the client, and the first table and the second table corresponding to each frequency band are maintained for different device providers.

S3, inquiring first uplink signal strength RSSI of client₁。

S4, monitoring whether the client is in a suspended state; if the client is in the suspend state, go to step S5; if the client is in the non-suspended state, the process proceeds to step S6.

S5, judging the RSSI not less than the second preset condition a1₁-tempRSSI ≦ a 2. If yes, the interval is 1 second, and the step returns to the step S3; if not, the suspend state of the client is released, and the process returns to step S3 at an interval of 1 second.

S6, the RSSI of the first uplink signal strength inquired in the step S3₁Uplink signal strength RSSI as a client_currIf there is no RSSI in the first table_currCorresponding entry, then (RSSI)_curr，P(RSSI_curr) O.5) is added to the first table. Querying a first trigger probability P (RSSI) from a first table associated with a client_curr)。

S7, at random [ O, 1]]Generating a random number if not greater than P (RSSI)_curr) Then, go to step S8; if greater than P (RSSI)_curr) Then, at an interval of 1 second, the process returns to step S3.

S8, sending RRM request to the client, if not receiving the reply message of the client, entering step S9; if the reply message of the client is received, the step S10 is carried out;

s9, updating P (RSSI) according to formula P' (RSSI) · P (RSSI) ·_curr). Return is made to step S3.

S10, obtaining each candidate BSSID from the reply message to the downlink signal strength RCPI of the client₁～RCPI₂₀Obtaining the current downlink signal strength RCPI_currMeter for measuringCalculation of △ RCPI_i＝RCPI_i-RCPI_curr. Will RSSI_currSubstituting the formula offset into b × offset₀+(1-b)×(RSSI-RCPI_curr) To update the compensation parameters.

S11, obtaining each index combination (RCPI)_curr，△RCPI_i) For index combinations that do not exist in the second table, a new index combination is added to the second table, and its corresponding second trigger probability is set to 0.5. Querying each index combination (RCPI) from a second table associated with the client_curr，△RCPI_i) Corresponding second trigger probability P (RCPI)_curr，△RCPI_i)。

S12, obtaining corresponding RCPI of each candidate BSSID according to prior data of each wireless AP_iThroughput per unit of time Thr (RCPI)_i) Sorting out the corresponding relation { BSSID_i，(RCPI_curr，△RCPI_i，P(RCPI_curr，△RCPI_i))，Thr(RCPI_i)}。

S13, judging whether P (RCPI) is satisfied or not_curr，ΔRCPI_i)*Thr(RCPI_i)≥d*Thr_currIf there is no candidate BSSID that satisfies the relational expression, the process proceeds to step S14; if there is a candidate BSSID that satisfies the relationship, the process proceeds to step S15.

S14, the target BSSID is the current BSSID, and the process proceeds to step S16.

S15, if the target BSSID is not the current BSSID, selecting P (RCPI) from the selected candidate BSSIDs_curr，ΔRCPI_i)*Thr(RCPI_i) And the candidate BSSID corresponding to the maximum value is used as the target BSSID. The process advances to step S17.

S16, setting the client to be in a suspended state, and updating a tempRSSI (uplink signal strength reference value), wherein the tempRSSI is RSSI_currAfter interval 5, the process returns to step S3.

S17, sending a BTM request to the client to instruct the client to roam to the target BSSID.

And S18, detecting the roaming state of the client. If the client roams successfully, go to step S19; if the roaming of the client fails, the process proceeds to step S20.

S19, according to the formula P' (RSSI) ═ × P (RSSI) + 1-to-P (RSSI)_curr) Updating is carried out; according to the formula P' (RCPI)_curr，ΔRCPI_i)＝×P(RCPI_curr，ΔRCPI_i) + 1-to-P (RCPI)_curr，△RCPI_i) And (6) updating. And releasing the association state of the client.

S20, according to the formula P' (RSSI) ═ × P (RSSI) to P (RSSI)_curr) Updating is carried out; according to the formula

Calculation of P (RCPI)_curr，ΔRCPI_i) Corresponding second step size parameter, and according to the formula P' (RCPI)_curr，ΔRCPI_i)＝′(RCPI_curr，ΔRCPI_i)·P(RCPI_curr，ΔRCPI_i) Combining each index in the second table (RCPI)_curr，ΔRCPI_i) Corresponding second trigger probability P (RCPI)_curr，ΔRCPI_i) And (6) updating. After the update is completed, the process waits for 5 seconds and returns to step S3.

And S21, corresponding to the related client, monitoring whether the client actively roams.

S22, when the active roaming of the ue is monitored, comparing the first trigger probability P (RSSI) of the first table with the formula P' (RSSI) ═ × P (RSSI) ((RSSI))_curr) Updating is carried out; according to the formula

Calculation of P (RCPI)_curr，ΔRCPI_i) Corresponding third step length parameter, and according to formula P' (RCPI, Δ RCPI) ═ m₃× P (RCPI, Δ RCPI) updates the second trigger probability P' (RCPI, Δ RCPI) corresponding to the index combination (RCPI, Δ RCPI). the client is set to the unassociated state.

In the roaming control method provided in the foregoing embodiment of the present invention, through steps S1 to S22, it is possible to reduce the number of times that the wireless AP repeatedly sends an unacceptable RRM request and a BTM request, and drive the wireless AP to send the RRM request and the BTM request in a successful roaming scenario, so that waste of network resources is reduced, and a client roaming success rate is improved. In addition, the roaming control method of the embodiment considers the processing procedures of scenes such as roaming failure, roaming success and active roaming, and the processing procedure of the suspension state of the client, and has higher robustness.

Example two

Fig. 6 is a schematic structural diagram of a roaming control device according to a preferred embodiment of the present invention. Specifically, the apparatus comprises:

an obtaining module 11, configured to obtain an uplink signal strength of the to-be-roamed client with respect to a currently associated current wireless AP;

the query module 12 is configured to query a first trigger probability corresponding to the uplink signal strength from a first table associated with the client to be roamed;

a triggering module 13, configured to trigger, with the first triggering probability, the current wireless AP to send an RRM request to the client to be roamed;

a selecting module 14, configured to, when an RRM request is sent to the client to be roamed and a reply message returned by the client to be roamed is received, select one of the candidate BSSIDs as a target BSSID according to each candidate BSSID of the client to be roamed and downlink signal strength from each candidate BSSID to the client to be roamed, where the candidate BSSID is included in the reply message;

an indicating module 15, configured to, when the target BSSID is not the current BSSID associated with the client to be roamed, indicate that the client to be roamed roams to the target BSSID, and detect a roaming state of the client to be roamed; and the number of the first and second electrodes,

a first updating module 16, configured to increase the first trigger probability corresponding to the uplink signal strength in the first table when it is detected that the roaming of the client to be roamed is successful; and when the roaming failure of the client to be roamed is detected, reducing the first trigger probability corresponding to the uplink signal strength in the first table.

Preferably, the selecting module specifically includes:

an obtaining unit, configured to obtain, according to prior data corresponding to each candidate BSSID obtained in advance, throughput corresponding to each downlink signal strength;

a first calculation unit configured to calculate a reference index for each of the candidate BSSIDs based on each of the throughputs;

a determining unit, configured to determine the target BSSID according to the reference indicator of each candidate BSSID.

Preferably, the first computing unit specifically includes:

a downlink signal strength difference calculating subunit, configured to obtain a current downlink signal strength from the current wireless AP to the client to be roamed, and calculate a downlink signal strength difference between each downlink signal strength and the current downlink signal strength;

the query subunit is configured to respectively form an index combination by the current downlink signal strength and each downlink signal strength difference, and query, from a second table associated with the client to be roamed, a second trigger probability corresponding to each index combination;

a reference index calculation subunit, configured to calculate a reference index for each candidate BSSID according to the second trigger probability and the throughput corresponding to each index combination;

then, the apparatus further comprises:

a second updating module, configured to, after the indicating module 15 detects the roaming state of the to-be-roamed client, increase a second trigger probability corresponding to each index combination in the second table when it is detected that the to-be-roamed client successfully roams; and when the roaming failure of the client to be roamed is detected, reducing the second trigger probability corresponding to each index combination in the second table.

Preferably, the reference indicator calculating subunit calculates the reference indicator for each of the candidate BSSIDs by the following formula:

I_i＝P(RCPI_curr，ΔRCPI_i)*Thr(RCPI_i)；

Preferably, the second updating module specifically includes:

a first updating unit, configured to update, when it is detected that the roaming of the client to be roamed is successful, the second trigger probability corresponding to each index combination in the second table according to the following formula:

P′(RCPI_curr，ΔRCPI_i)＝×P(RCPI_curr，ΔRCPI_i)+1-

Preferably, the second updating module further comprises:

a second updating unit, configured to, when it is detected that the roaming of the client to be roamed fails, calculate a second step length parameter of a second trigger probability corresponding to each index combination according to the following formula:

P′(RCPI_curr，ΔRCPI_i)＝′(RCPI_curr，ΔRCPI_i)×P(RCPI_curr，ΔRCPI_i)

Preferably, the determining unit specifically includes:

a first determining subunit, configured to determine, when there is a reference index that satisfies a first preset condition among all reference indexes of the candidate BSSIDs, an optimal reference index from among all reference indexes that satisfy the first preset condition; determining candidate BSSIDs corresponding to the optimal reference indexes as the target BSSIDs;

a second determining subunit, configured to determine, when none of the reference indicators of all the candidate BSSIDs has a reference indicator that satisfies a first preset condition, a current BSSID associated with the client to be roamed as the target BSSID.

Preferably, the first preset condition includes:

I_i≥d*Thr_curr

Preferably, the first updating module specifically includes:

a third updating unit, configured to update the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula when it is detected that the roaming of the client to be roamed is successful:

P′(RSSI)＝×P(RSSI)+1-

Preferably, the first updating module specifically includes:

a fourth updating unit, configured to update the first trigger probability corresponding to the uplink signal strength in the first table according to the following formula when it is detected that the roaming of the client to be roamed fails:

P′(RSSI)＝×P(RSSI)

Preferably, the apparatus further comprises:

a third updating module, configured to, after the triggering module triggers the current wireless AP to send the RRM request to the client to be roamed with the first triggering probability, update the first triggering probability corresponding to the uplink signal strength in the first table according to the following formula when the RRM request is sent to the client to be roamed and a reply packet returned by the client to be roamed is not received:

P′(RSSI)＝×P(RSSI)

Preferably, the apparatus further includes a fourth updating module, and the fourth updating module specifically includes:

a fifth updating unit, configured to increase the first trigger probability corresponding to the uplink signal strength in the first table when it is monitored that the to-be-roamed client performs active roaming;

a third step length parameter calculating unit, configured to calculate third step length parameters of all the second trigger probabilities in the second table;

a sixth updating unit, configured to update all the second probabilities in the second table according to the third step size parameter.

Preferably, the fifth updating unit is specifically configured to:

P′(RSSI)＝×P(RSSI)+1-

Preferably, the apparatus further comprises:

a compensation parameter updating module, configured to, when an RRM request is sent to the client to be roamed and a reply packet returned by the client to be roamed is received, perform a numerical update on a preset compensation parameter according to the following formula:

offset＝b×offset₀+(1-b)×(RSSI-RCPI_curr)

then, the third step length parameter calculating unit calculates the third step length parameters of all the second trigger probabilities in the second table by using the following formula:

Preferably, the sixth updating unit is specifically configured to:

P′(RCPI，ΔRCPI)＝₃×P(RCPI，ΔRCPI)

Preferably, the triggering module is specifically configured to:

randomly generating a random number in the [ O, 1] interval;

Preferably, the apparatus further comprises:

a suspension triggering module, configured to, after the selection of one of the candidate BSSIDs as a target BSSID, trigger the client to be roamed to be in a suspension state when the target BSSID is the current BSSID; the current wireless AP forbids to send an RRM request to a client to be roamed in a suspended state; and the current wireless AP initializes the first-associated client to be roamed into a non-suspended state.

Preferably, the obtaining module is specifically configured to perform the following steps:

Preferably, the apparatus further comprises:

a fifth updating module, configured to update an uplink signal strength reference value according to the uplink signal strength after the target BSSID is the current wireless AP and the client to be roamed is triggered to be in a suspended state;

then, the second preset condition is:

a1≤RSSI₁-tempRSSI≤a2

wherein the content of the first and second substances,RSSI₁the first uplink signal strength; a1 is a first preset value; a2 is a second preset value; and the tempRSSI is the uplink signal strength reference value.

The roaming control device provided by the invention can consider the response condition of the client to the roaming control of the wireless AP, and update the first trigger probability in the scenes of successful roaming and failed roaming.

It should be noted that the functions of the roaming control apparatus provided in the embodiment of the present invention correspond to the steps of the roaming control method described in the above embodiment, and the working principles and beneficial effects of the two correspond to each other, so that the detailed description is omitted.

EXAMPLE III

Fig. 7 shows a schematic structural diagram of a wireless device according to a preferred embodiment of the present invention. Specifically, the wireless device includes a processor 10, a memory 20, and a computer program stored in the memory and configured to be executed by the processor, and the processor executes the computer program to implement the roaming control method according to any one of the embodiments.

In particular, the processor and the memory in the wireless device may be one or more.

The wireless device of the present embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the roaming control method provided in the above embodiments are implemented, for example, step S100 shown in fig. 1, and the uplink signal strength of the client to be roamed with respect to the currently associated current wireless AP is obtained. Or, the processor, when executing the computer program, implements the functions of the modules in the foregoing device embodiments, for example, implements the obtaining module 11, configured to obtain the uplink signal strength of the to-be-roamed client relative to the currently associated current wireless AP.

Illustratively, the computer program can be divided into one or more modules/units (e.g., computer program 1, computer program 2, shown in FIG. 7), which are stored in the memory and executed by the processor to implement the invention. The one or more modules/units may be a series of computer program instruction segments capable of performing certain functions, which are used to describe the execution of the computer program in the wireless device. For example, the computer program may be divided into an acquisition module 11, a query module 12, a trigger module 13, a selection module 14, an indication module 15, a first update module 16, a feature quantity acquisition module 17, and an extraction module 18, where the specific functions of the modules are as follows:

The Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. The general purpose processor may be a microprocessor or the processor may be any conventional processor or the like that is the control center for the wireless device and that connects the various parts of the overall wireless device using various interfaces and lines.

The memory may be used to store the computer programs and/or modules, and the processor may implement various functions of the wireless device by executing or otherwise executing the computer programs and/or modules stored in the memory, as well as by invoking data stored in the memory. The memory may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the cellular phone, and the like. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), at least one magnetic disk storage device, a Flash memory device, or other volatile solid state storage device.

Wherein the wireless device integrated module/unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the roaming control method provided by the above embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the steps of any roaming control method provided by the above embodiments may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

It should be noted that the wireless device may include, but is not limited to, a processor and a memory, and those skilled in the art will understand that the structural diagram of fig. 7 is only an example of the wireless device and does not constitute a limitation of the wireless device, and may include more or less components than those shown, or combine some components, or different components.

Example four

The present invention also provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program runs, the apparatus in which the computer-readable storage medium is located is controlled to execute the roaming control method according to any one of the above embodiments.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. A roaming control method, characterized in that the method comprises:

2. The roaming control method of claim 1, wherein the selecting one of the candidate BSSIDs as the target BSSID specifically comprises:

3. The roaming control method of claim 2, wherein the calculating a reference index for each candidate BSSID based on each throughput includes:

4. The roaming control method of claim 3, wherein the method calculates a reference indicator for each of the candidate BSSIDs by:

I_i＝P(RCPI_curr,ΔRCPI_i)*Thr(RCPI_i)；

wherein, I_iA reference index for the ith said candidate BSSID; RCPI_currThe current downlink signal strength is obtained; RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; p (RCPI)_curr,ΔRCPI_i) Is an index combination (RCPI)_curr，ΔRCPI_i) A corresponding second trigger probability; thr (RCPI)_i) For the ith candidate BSSID, the downlink signal strength is RCPI_iThe throughput of time.

5. The roaming control method of claim 3, wherein the increasing the second trigger probability corresponding to each index combination in the second table when detecting that the roaming of the to-be-roamed client is successful comprises:

P′(RCPI_curr,ΔRCPI_i)＝×P(RCPI_curr,ΔRCPI_i)+1-

wherein, RCPI_currFor the current downlink signal strength, RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; p (RCPI)_curr,ΔRCPI_i) In combination with an index (RCPI)_curr,ΔRCPI_i) A corresponding second trigger probability before updating; p' (RCPI)_curr,ΔRCPI_i) In combination with an index (RCPI)_curr,ΔRCPI_i) A corresponding updated second trigger probability; is a first step length parameter less than 1.

6. The roaming control method of claim 3, wherein the reducing, when it is detected that the roaming of the to-be-roamed client fails, the second trigger probability corresponding to each index combination in the second table specifically includes:

P′(RCPI_curr,ΔRCPI_i)＝′(RCPI_curr,ΔRCPI_i)×P(RCPI_curr,ΔRCPI_i)

wherein, RCPI_currThe current downlink signal strength is obtained; RCPI_iThe downlink signal strength to the client to be roamed for the ith candidate BSSID; delta RCPI_iFor the downlink signal strength RCPI_iAnd the current downlink signal strength RCPI_currThe downlink signal strength difference therebetween; RCPI_targetThe downlink signal strength corresponding to the target BSSID is obtained; delta RCPI_targetFor the downlink signal strength RCPI_targetAnd the current downlink signal strength RCPI_currThe difference between the downlink signal strengths, α is a preset control coefficient, P (RCPI)_curr,ΔRCPI_i) In combination with an index (RCPI)_curr,ΔRCPI_i) A corresponding second trigger probability before updating; ' (RCPI)_curr,ΔRCPI_i) Is the second trigger probability P (RCPI)_curr,ΔRCPI_i) A corresponding second step size parameter; p' (RCPI)_curr,ΔRCPI_i) In combination with an index (RCPI)_curr,ΔRCPI_i) A corresponding updated second trigger probability.

7. The roaming control method of claim 2, wherein the determining the target BSSID based on the reference indicator for each candidate BSSID specifically comprises:

8. The roaming control method of claim 7, wherein the first preset condition includes:

I_i≥d*Thr_curr

9. The roaming control method of claim 1, wherein the increasing the first trigger probability corresponding to the uplink signal strength in the first table when it is detected that the roaming of the to-be-roamed client is successful comprises:

P′(RSSI)＝×P(RSSI)+1-

10. The roaming control method of claim 1, wherein the reducing the first trigger probability corresponding to the uplink signal strength in the first table when the roaming failure of the to-be-roamed client is detected comprises:

P′(RSSI)＝×P(RSSI)

11. The roaming control method of claim 1, wherein after the triggering the current wireless AP to send an RRM request to the client to be roamed with the first trigger probability, the method further comprises:

P′(RSSI)＝×P(RSSI)

12. The roaming control method of claim 3, wherein the method further comprises:

13. The roaming control method of claim 12, wherein the increasing the first trigger probability corresponding to the uplink signal strength in the first table when it is monitored that the ue is actively roaming includes:

P′(RSSI)＝×P(RSSI)+1-

14. The roaming control method of claim 12, wherein the method further comprises:

offset＝b×offset₀+(1-b)×(RSSI-RCPI_curr)

15. The roaming control method of claim 12, wherein the updating all of the second probabilities in the second table according to the third step size parameter includes:

P′(RCPI,ΔRCPI)＝₃×P(RCPI,ΔRCPI)

16. The roaming control method of claim 1, wherein the triggering the current wireless AP to send the RRM request to the client to be roamed with the first trigger probability includes:

randomly generating a random number in the interval of [0,1 ];

17. The roaming control method of claim 1, wherein after the selecting one of the candidate BSSIDs as a target BSSID, the method further comprises:

18. The roaming control method of claim 17, wherein the obtaining the uplink signal strength of the to-be-roamed client with respect to the currently associated current wireless AP specifically comprises:

19. The roaming control method of claim 17, wherein after the triggering the to-be-roamed client to be in a suspended state when the target BSSID is the current wireless AP, the method further comprises:

then, the second preset condition is:

a1≤RSSI₁-tempRSSI≤a2

20. A roaming control apparatus, characterized in that the apparatus comprises:

21. A wireless device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, the processor implementing the roaming control method of any one of claims 1-19 when executing the computer program.

22. A computer-readable storage medium, comprising a stored computer program, wherein the computer program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform the roaming control method of any one of claims 1 to 19.