CN101610553B - Method for quick multi-wireless module switching - Google Patents
Method for quick multi-wireless module switching Download PDFInfo
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- CN101610553B CN101610553B CN2008100712373A CN200810071237A CN101610553B CN 101610553 B CN101610553 B CN 101610553B CN 2008100712373 A CN2008100712373 A CN 2008100712373A CN 200810071237 A CN200810071237 A CN 200810071237A CN 101610553 B CN101610553 B CN 101610553B
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Abstract
The invention discloses a method for quick multi-wireless module switching, which comprises the following steps that: an independent primary wireless module undertakes a foreground wireless transmission task and an independent secondary wireless module undertakes a background scanning task at the same time to realize the synchronous operation of foreground wireless transmission and background scanning; when the secondary wireless module finds a new target AP with higher signal quality, the target AP is switched to for forming a secondary link; when the transmission performance of the secondary link is advantageous over that of a primary link, the primary and secondary priorities of the two links is switched; a two-layer routing is updated according to the switched links; and the previous processes is circularly executed. The method has the advantages of realizing real network seamless switching due to the fact that the secondary link is already superior to the primary link during the execution of primary/secondary link switching and allowing a product which is based on the method to keep continuous network connection unlike the prior station active switch method and the prior IAPP method both of which are incapable of realizing vehicle-mounted fast moving application and cause obvious network interruption during the execution of inter-AP switching in a running process of a vehicle.
Description
[technical field]
The invention relates to the cut-in method of main line of communication WiMAX in a kind of wireless network, be meant a kind of method for quick multi-wireless module switching especially.
[background technology]
Switch fast is that main line of communication WiMAX inserts one of key technology difficult problem that runs into.Can't satisfy the fast moving of the main line of communication and use switching time in 1～2s between the AP (Access Point, WAP (wireless access point)) of tradition WiFi (Wireless Fidelity, Wireless Fidelity).At highway, the speed of travelling the soonest of automobile reaches 120km/h, and the present high-speed railway of China has reached more than 200 kilometers/hour, just near 40m/s.Because the coverage distance of WiFi is limited, cover even adopt directional antenna to carry out orientation along road, for guaranteeing access effect preferably, its coverage distance is general all in 1 kilometer.With the switch speed of common AP, the vehicle of fast running is from entering the AP overlay area to leaving, and its residence time is less than 25s, and the better quality of signal time is less than 20s, has a strong impact on transmission of Information, particularly for the transmission of Streaming Media.
Website active changing method according to 802.11 protocol definitions, at same extended service set (ESS, Extended Service Set) in, as STA (Station, wireless site) lose current connection after, STA will carry out the AP scanning process and according to eating dishes without rice or wine signal quality, select the AP that wherein signal is the strongest to insert as switching target.Support AP method for switching between IAPP (Inter-Access Point Protocol fast 802.11s defined, access point interoperability agreement), the IAPP method just can switch to a target AP that signal quality is more excellent before current connection is interrupted fully, the relative website of its performance of handoffs initiatively changing method has had and significantly improves.
Adopt 802.11 website active changing method, except hundreds of milliseconds handoff delay, also have the defective of following 3 aspects: 1) all AP must belong to same ESS, promptly are configured to identical ESSID (ESS identification number); As long as and be configured to identical ESSID, this AP then becomes the access target of STA; 2) before carrying out the AP switching, its transmission performance is rapid deterioration; 3) after carrying out the AP switching, the optimization of its transmission performance also is a process slowly.
And for the IAPP method, because STA only has a wireless module, it has the defective of following 2 aspects: 1) the background scanning process will make foreground wireless transmission process interrupt hundreds of milliseconds; 2) after carrying out the AP switching, the optimization of its transmission performance remains a process slowly.
For the vehicle-carrying communication gateway, because its car-ground wireless transmission link need carry the data flow of whole In-vehicle networking correspondence with foreign country, the foreground wireless transmission does not have free time to leave the background scanning process for to be close to AP scanning usually.There is not background scanning just cannot find new target AP.Obviously, background scanning is the key of IAPP changing method, and if force to carry out background scanning, then all will make the foreground wireless transmission interrupt hundreds of milliseconds at every turn.
[summary of the invention]
Technical problem to be solved by this invention is two critical defects at above-mentioned IAPP method, and the method for quick multi-wireless module switching of seamless switching between a kind of AP of support is provided.
The present invention solves the problems of the technologies described above by the following technical programs: a kind of method for quick multi-wireless module switching comprises the steps:
1) at first adopts main wireless module and, be responsible for foreground wireless transmission task, by independently being responsible for the background scanning task, realize the concurrent work of foreground wireless transmission and background scanning simultaneously from wireless module by main wireless module independently from wireless module;
2) when searching out the more excellent Target Wireless access point of new signal quality from wireless module, then switch to the Target Wireless access point, form, promptly from the link of wireless module with Target Wireless access point formation from link;
3) transmission performance from link progressively is optimized;
4) when the transmission performance from link is better than primary link, switch the principal and subordinate role of two links, being about to former is primary link from link switchover, and former primary link is switched to from link;
5) upgrade two layers of route according to the link that switched;
6) return step 1), above-mentioned process is carried out in circulation.
This invention can further be specially:
Described step 1) further comprises:
Main wireless module and to drive respectively from wireless module be No. 1 network interface (for example identifier is wlan0) and No. 2 network interfaces (for example identifier is wlan1), adopt binding module bonding then, with master slave mode (Acitve-Backup) No. 1 network interface and No. 2 network interfaces are bundled and virtual be a network interface (for example identifier is bond0);
No. 1 network interface and current wireless access point keep normal data communication, report the various information of current wireless access point simultaneously by primary link monitoring subprogram, No. 2 network interfaces are the WAP (wireless access point) around the periodic scan then, simultaneously by the various information from link monitoring subprogram reporting objectives WAP (wireless access point).
Described step 2) further comprise: No. 2 network interface periodic scan WAP (wireless access point) is on every side tabulated to upgrade candidate's WAP (wireless access point), and chooses optimum WAP (wireless access point) and insert as the Target Wireless access point, forms from link.
Described primary link monitoring subprogram comprises the following step of carrying out successively:
Obtain status of primary link, comprise the various information of current wireless access point;
Do you judge that current primary link has or not normal connection? do not connect if having, then connect primary link again, obtain status of primary link then again, if normal the connection enters next step;
Whether this connection illegal? if connect illegally, then connect primary link again, obtain status of primary link then again, if connection is legal, then directly returns and obtain the status of primary link step again.
The described following step of carrying out successively that comprises from the link monitoring subprogram:
Obtain from Link State, comprise the various information of Target Wireless access point;
Does judgement have or not normal connection from link? do not connect if having, then connect again, obtain again then, if normal the connection enters next step from Link State from link;
Whether this connection illegal? if connect illegally, then connect again from link, obtain again then from Link State, if connection is legal, then directly returns and obtain again from the Link State step.
Described step 4) further comprises: when the judgement subprogram is found when link is better than primary link, then fill order to realize the switching of master/slave link, exchanges the identifier title of principal and subordinate's wireless module then, after the switching, master/slave wireless module is originally exchanged the role mutually.
Described judgement subprogram comprises the following step of carrying out successively:
Step 510: judge at first whether the current wireless access point fine? if fine, termination routine then; Otherwise, enter next step;
Step 512: judge whether the current wireless access point very poor? if very poor, then enter step 514, if not very poor, then enter step 520;
Step 514: judge whether the Target Wireless access point is very poor, if very poor, termination routine then, otherwise, switch back;
Does step 520: the current wireless access point descend? if, enter step 524, otherwise, step 522 entered;
Step 522: judge whether the Target Wireless access point is fine, if not termination routine then is if then switch back;
Step 524: judge whether the Target Wireless access point is fine, if, then switch back, if not, step 526 then entered;
Step 526: judge whether the Target Wireless access point is very poor, if, termination routine then, if not, step 528 then entered;
Step 528: judge whether the Target Wireless access point rises, if, then switch back, if not, termination routine then.
Described main wireless module and be integrated in positive and negative respectively based on embedded system from wireless module, thus air interference to each other avoided.
The advantage of a kind of method for quick multi-wireless module switching of the present invention is: owing to be master/slave link switchover with switch transition between the AP of WiFi, so the uninterrupted network when this method has realized switching between AP connects; Owing to when carrying out master/slave link switchover, be better than primary link, so this method has realized real seamless switching from link.Thereby method for quick multi-wireless module switching has solved two defectives that the IAPP changing method exists, and can support the seamless switching between AP.With respect to existing website initiatively changing method and IAPP method can't realize that all vehicle-mounted fast moving uses, carrying out in the vehicle ' process when switching between AP has tangible network to interrupt, and can keep continual network to connect based on the product of this method.
[description of drawings]
The invention will be further described in conjunction with the embodiments with reference to the accompanying drawings.
Fig. 1 is the fundamental diagram of a kind of method for quick multi-wireless module switching of the present invention.
Fig. 2 is the workflow diagram of a kind of method for quick multi-wireless module switching of the present invention.
Fig. 3 is a primary link monitoring subroutine flow chart.
Fig. 4 is from the link monitoring subroutine flow chart.
Fig. 5 is the judgement subroutine flow chart.
[embodiment]
The wireless module of this method for quick multi-wireless module switching employing more than two comprises main wireless module and from wireless module, wherein main wireless module is responsible for foreground wireless transmission task, is responsible for background scanning from wireless module.
This method for quick multi-wireless module switching comprises the steps:
1) is responsible for foreground wireless transmission task by main wireless module independently,, thereby realizes the concurrent work of foreground wireless transmission and background scanning simultaneously by independently being responsible for the background scanning task from wireless module;
2) when searching out the more excellent target AP of new signal quality from wireless module, then switch to target AP, form, promptly from the link of wireless module with the target AP formation from link;
3) transmission performance from link progressively is optimized;
4) when the transmission performance from link is better than primary link, switch the principal and subordinate position of two links, being about to former is primary link from link switchover, and former primary link is switched to from link;
5) upgrade two layers of route according to the link that switched;
6) return step 1), above-mentioned process is carried out in circulation.
See also Fig. 1 and 2, below the present invention is set forth in more detail.
A kind of method for quick multi-wireless module switching of the present invention at first needs to carry out the configuration of hardware components, based on embedded system (as IXP425) integrated a plurality of wireless modules, as each wireless module of positive and negative, as main wireless module and from wireless module, realize the concurrent working of foreground wireless transmission task and background scanning task respectively respectively.
Software section is as hardware driving and primary control program, realize the seamless switching between AP, its operation principle as shown in Figure 1, main wireless module and to drive respectively from wireless module be No. 1 network interface 10 (for example identifier is wlan0), No. 2 network interfaces 20 (for example identifier is wlan1), adopt network card binding module bonding 30 that No. 1 network interface 10 and No. 2 network interfaces 20 are bundled then and virtual be a network interface 40 (for example identifier is bond0).Wherein, No. 1 network interface 10 and No. 2 network interfaces 20 adopt master/slave pattern, be responsible for foreground wireless transmission task by main wireless module, i.e. No. 1 network interface 10 and current wireless access point (AP) normal data transfer of carrying out, carry out background scanning from wireless module simultaneously, promptly No. 2 network interfaces 20 scan and insert Target Wireless access point (AP), when the signal quality of Target Wireless access point is better, then carry out master/slave link switchover: this moment, No. 2 network interfaces 20 became main wireless module, be responsible for transfer of data, connected Target Wireless access point becomes the current wireless access point, No. 1 network interface 10 then becomes from wireless module, begins to scan new Target Wireless access point.Because No. 1 network interface 10 and No. 2 network interfaces 20 are virtual to be a network interface 40, then is transparent fully so use for upper layer network.
The workflow of this method for quick multi-wireless module switching comprises the steps: as shown in Figure 2
Initialization;
No. 1 network interface 10 keeps normal data communication with the current wireless access point, report the various information of current wireless access point simultaneously by primary link monitoring subprogram, comprise signal quality information, base station sub-system sign (BSSID, Base Station Subsystem Density), extended service set identification information such as (ESSID);
WAP (wireless access point) around 20 periodic scan of No. 2 network interfaces is tabulated to upgrade candidate's WAP (wireless access point), and chooses optimum WAP (wireless access point) and insert as the Target Wireless access point;
By various information, comprise information such as signal quality information, base station sub-system sign, extended service set identification simultaneously from link monitoring subprogram reporting objectives WAP (wireless access point);
When the judgement subprogram is found then to carry out the switching of master/slave link when link is better than primary link, be responsible for normal transfer of data and No. 1 network interface 10 carries out periodic scan by No. 2 network interfaces 20, repeat said process.
See also Fig. 3, above-mentioned primary link monitoring subprogram comprises the following step of carrying out successively:
Obtain status of primary link, comprise the various information of current wireless access point: signal quality information, base station sub-system sign (BSSID, Base Station Subsystem Density), extended service set identification information such as (ESSID);
Do you judge that current primary link has or not normal connection? do not connect if having, then connect primary link again, obtain status of primary link then again, if normal the connection enters next step;
Whether this connection illegal? if connect illegally, then connect primary link again, obtain status of primary link then again, if connection is legal, then directly returns and obtain the status of primary link step again.
See also Fig. 4, the above-mentioned following step of carrying out successively that comprises from the link monitoring subprogram:
Obtain from Link State, comprise the various information of Target Wireless access point: signal quality information, base station sub-system sign (BSSID, Base Station Subsystem Density), extended service set identification information such as (ESSID);
Does judgement have or not normal connection from link? do not connect if having, then connect again, obtain again then, if normal the connection enters next step from Link State from link;
Whether this connection illegal? if connect illegally, then connect again from link, obtain again then from Link State, if connection is legal, then directly returns and obtain again from the Link State step.
See also Fig. 5, above-mentioned judgement subprogram comprises the following step of carrying out successively:
Step 510: judge at first whether the current wireless access point fine? if fine, termination routine then; Otherwise, enter next step;
Step 512: judge whether the current wireless access point very poor? if very poor, then enter step 514, if not very poor, then enter step 520;
Step 514: judge whether the Target Wireless access point is very poor, if very poor, termination routine then, otherwise, switch back;
Does step 520: the current wireless access point descend? if, enter step 524, otherwise, step 522 entered;
Step 522: judge whether the Target Wireless access point is fine, if not termination routine then is if then switch back;
Step 524: judge whether the Target Wireless access point is fine, if, then switch back, if not, step 526 then entered;
Step 526: judge whether the Target Wireless access point is very poor, if, termination routine then, if not, step 528 then entered;
Step 528: judge whether the Target Wireless access point rises, if, then switch back, if not, termination routine then.
Though more than described the specific embodiment of the present invention; but being familiar with those skilled in the art is to be understood that; our described specific embodiment is illustrative; rather than be used for qualification to scope of the present invention; those of ordinary skill in the art are in the modification and the variation of the equivalence of doing according to spirit of the present invention, all should be encompassed in the scope that claim of the present invention protects.
Claims (7)
1. a method for quick multi-wireless module switching is characterized in that: comprise the steps:
1) at first adopts main wireless module and, be responsible for foreground wireless transmission task, by independently being responsible for the background scanning task, realize the concurrent work of foreground wireless transmission and background scanning simultaneously from wireless module by main wireless module independently from wireless module;
2) when searching out the more excellent Target Wireless access point of new signal quality from wireless module, then switch to the Target Wireless access point, form, promptly from the link of wireless module with Target Wireless access point formation from link;
3) transmission performance from link progressively is optimized;
4) when the transmission performance from link is better than primary link, switch the principal and subordinate position of two links, being about to former is primary link from link switchover, and former primary link is switched to from link;
5) upgrade two layers of route according to the link that switched;
6) return step 1), above-mentioned steps is carried out in circulation.
2. a kind of method for quick multi-wireless module switching as claimed in claim 1 is characterized in that: described step 1) further comprises:
Main wireless module and to drive respectively from wireless module be No. 1 network interface, No. 2 network interfaces, adopt binding module that No. 1 network interface and No. 2 network interfaces are bundled then and virtual be a network interface;
No. 1 network interface and current wireless access point keep normal data communication, report the various information of current wireless access point simultaneously by primary link monitoring subprogram, No. 2 network interfaces are the WAP (wireless access point) around the periodic scan then, simultaneously by the various information from link monitoring subprogram reporting objectives WAP (wireless access point).
3. a kind of method for quick multi-wireless module switching as claimed in claim 2, it is characterized in that: described step 2) further comprise: No. 2 network interface periodic scan WAP (wireless access point) on every side is to upgrade the tabulation of candidate's WAP (wireless access point), and choose optimum WAP (wireless access point) and insert as the Target Wireless access point, form from link.
4. a kind of method for quick multi-wireless module switching as claimed in claim 2 is characterized in that: described primary link monitoring subprogram comprises the following step of carrying out successively:
Obtain status of primary link, comprise the various information of current wireless access point;
Do you judge that current primary link has or not normal connection? do not connect if having, then connect primary link again, obtain status of primary link then again, if normal the connection enters next step;
Whether this connection illegal? if connect illegally, then connect primary link again, obtain status of primary link then again, if connection is legal, then directly return the correlation step of obtaining status of primary link.
5. a kind of method for quick multi-wireless module switching as claimed in claim 2 is characterized in that: the described following step of carrying out successively that comprises from the link monitoring subprogram:
Obtain from Link State, comprise the various information of Target Wireless access point;
Does judgement have or not normal connection from link? do not connect if having, then connect again, obtain again then, if normal the connection enters next step from Link State from link;
Whether this connection illegal? if connect illegally, then connect again from link, obtain again then from Link State, if connection is legal, then directly return the correlation step of obtaining from Link State.
6. a kind of method for quick multi-wireless module switching as claimed in claim 3, it is characterized in that: described step 4) further comprises: when the judgement subprogram is found when link is better than primary link, then carry out the switching of master/slave link, No. 1 network interface carries out periodic scan by No. 2 responsible normal transfer of data of network interface.
7. a kind of method for quick multi-wireless module switching as claimed in claim 1 is characterized in that: described main wireless module and be integrated in positive and negative based on embedded system respectively from wireless module.
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Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102209354B (en) * | 2010-03-31 | 2013-11-13 | 中兴智能交通（无锡）有限公司 | Switching method, system and wireless network card for vehicle-mounted communication |
| CN103179643B (en) * | 2011-12-20 | 2017-06-06 | 华为技术有限公司 | Vehicle-mounted communication method, apparatus and system |
| CN103401732A (en) * | 2013-08-12 | 2013-11-20 | 东南大学 | Pseudo wireless access point data analysis system and method thereof |
| CN105100057A (en) * | 2015-06-05 | 2015-11-25 | 北京奇虎科技有限公司 | Application data processing method and system |
| EP3104636B8 (en) * | 2015-06-12 | 2021-12-29 | ALSTOM Transport Technologies | Improved wifi communication system for the exchange of data between a railway vehicle and a ground terminal |
| WO2017113398A1 (en) * | 2015-12-31 | 2017-07-06 | 华为技术有限公司 | Switchover method in master-slave network, master device, slave device, and system |
| CN107071840B (en) * | 2017-06-20 | 2019-12-03 | 成都西加云杉科技有限公司 | Netsurfing switching method and device |
| CN110650455B (en) * | 2019-09-12 | 2022-04-05 | 华侨大学 | Internet of vehicles access point switching method based on software defined network |
| CN110602704A (en) * | 2019-09-19 | 2019-12-20 | 深圳市瑞科慧联科技有限公司 | Non-sensing roaming system and method |
| CN111083768B (en) * | 2019-11-19 | 2022-05-31 | Oppo（重庆）智能科技有限公司 | Network connection control method, device, storage medium and electronic equipment |
| CN111698742B (en) * | 2020-06-08 | 2023-03-21 | 锐捷网络股份有限公司 | Data communication method, terminal device, electronic device, and computer storage medium |
| CN111741500B (en) * | 2020-08-03 | 2020-12-01 | 成都极米科技股份有限公司 | Roaming method in multilink scene, multilink device and storage medium |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1582051A (en) * | 2004-05-17 | 2005-02-16 | 北京航空航天大学 | Method for realizing network layer switching in mobile IP |
| CN1735051A (en) * | 2004-08-12 | 2006-02-15 | 华为技术有限公司 | Wireless switching device and its method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1582051A (en) * | 2004-05-17 | 2005-02-16 | 北京航空航天大学 | Method for realizing network layer switching in mobile IP |
| CN1735051A (en) * | 2004-08-12 | 2006-02-15 | 华为技术有限公司 | Wireless switching device and its method |
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