CN101848528B - Method and device for progressive channel scanning - Google Patents

Abstract

The invention relates to a method and a device for progressive channel scanning. The method firstly checks whether the previous scanning program finishes all channel scanning work to determine the initial scanning channel, and records the channel as the last scanning channel when finishing one channel scanning in the scanning process. In addition, the method uses the effective service setting identifier and scans the channel in an active scanning mode to improve the opportunity of obtaining the hidden access point information.

Description

The method and apparatus of progressive channel scanning

Technical field

The present invention relates to a kind of communication system, relate to a kind of method and apparatus of progressive channel scanning in particular.

Background technology

Along with wireless lan (wlan) is universal day by day, various application also develops rapidly thereupon, and many team also devote the research that promotes any wireless network services quality in succession.In WLAN, and mobile wireless transmission unit (wireless transmit/receive unit, WTRU) or platform (station) maybe simultaneously (access point be in signal transmission ranges AP) at a plurality of access points.Yet, along with the communication connecting object and the employed channel of said wireless transmission/receive unit of time possibly need be reselected because of the variation of signal strength signal intensity.Mobile wireless transmission unit is obtained to be connected with access point must have a handover (handoff) before so that continue communication; Said handover contains scanning (scanning), checking (authentication) and combines (reassociation) three phases again, and wherein the time delay with sweep phase is the longest.Like platform is twin-channel platform; It has 38 and supports channel of operation (channel 1 is to channel 14, channel 36, channel 40, channel 44, channel 48, channel 52, channel 56, channel 60, channel 64, channel 100, channel 104, channel 108, channel 112, channel 116, channel 120, channel 124, channel 128, channel 132, channel 136, channel 140, channel 149, channel 153, channel 157, channel 161, channel 165); Channel of every scanning spends 140 milliseconds approximately, therefore needs 5320 milliseconds approximately and accomplishes all scan channels.Yet, if the employed operating system of platform is Microsoft's Window XP (Microsoft Windows XP), after beginning to carry out scan channel about 3 second system be the active break scanning work.Therefore, just can't accomplish all scan channel work for twin-channel platform.If its employed channel of the access point that said platform will connect is not accomplished scanning, just so said platform can't be connected with it.

Fig. 1 describes the sketch map of the scanning process of platform.Operating system is to the wireless device driver issue scan request of platform.The wireless device driver is removed previous all scanning results earlier, so that begin scanning from channel 1.As stated, operating system after beginning to carry out scan channel about 3 second system be the active break scanning work, concurrent cloth is enumerated request.Therefore, this scanning imaging system only can be accomplished the scanning work of channel 1 to channel 64.On the other hand, the wireless device driver all can be removed the previous all scanning results and the scanning that starts anew earlier before starting scanning imaging system.Therefore, scanning imaging system only can be accomplished the local channel scanning work each time.In other words, just said platform can't be obtained with the access point that operates in other channel (like channel 153) is connected.

Summary of the invention

The method and apparatus of progressive channel scanning of the present invention judges whether a preceding scanning imaging system accomplishes all scan channel work earlier.If scanning and delete the previous scanning result of channel described in the sweep record before one channel in scanning so starts anew.To be about to said channel record be last scanning channel to every completion one scan channel in the scanning process.If the preceding local channel scanning work of once only accomplishing is so from the scanning that begins to continue of last scanning channel.In addition, the present invention also uses effective service setting identifier with active scan mode scanning channel.

Enforcement example of the present invention discloses a kind of method of progressive channel scanning, and said method comprises following steps: whether inspection is accomplished the scan channel program and is obtained the scanning indication; According to said scanning indicative of settings channel to be scanned; If the information of said channel to be scanned is present in the scanning record, the information of from said scanning record, deleting said channel to be scanned so; And scan said channel to be scanned.

Enforcement example of the present invention discloses a kind of device of progressive channel scanning, and it comprises setup unit, scanning element, record cell and inspection unit.Said setup unit is in order to set channel to be scanned.Said scanning element is in order to scan said channel to be scanned.Said record cell is in order to publishing at least one scanning result in the said scanning element in scanning record, and is last scanning channel with said channel record to be scanned.Said inspection unit is in order to checking said at least one scanning result in the said record cell, and determines next channel to be scanned.

Description of drawings

Fig. 1 describes the sketch map of scanning process;

Fig. 2 describes the flow chart of the progressive channel scanning method of enforcement example of the present invention;

Fig. 3 describes the flow chart of the detailed step of step S206; And

Fig. 4 describes of the present invention another and implements the block diagram of the progressive channel scanning device of example.

Embodiment

Fig. 2 shows the flow chart of the progressive channel scanning method of enforcement example of the present invention.In step S201, the operating system of platform issue scan request is to start the scan channel flow process.In step S202, carry out the scan channel program, and with outcome record in the scan channel record.(Institute of Electrical and Electronics Engineers, IEEE) in 802.11 standards of institute's standard, at sweep phase, platform must scan all channels in IEEE.At present, said scan mode can be divided into active scanner uni passive type scanning.In active scanning, the platform selective channel also transmits probe request frame (probe request frame), waits for that then the given time is to receive the probe request frame of response.If after said given time, do not receive the probe request frame of said response, adjust to a new channel so and repeat this program.In passive type scanning, the given time of platform selective channel and monitoring (listening).If after the said given time, do not receive any beacon frame (beacon frame) broadcasting, adjust to a new channel so and repeat this program.In step S203, judge whether to accomplish all exercisable channels of the said platform of scanning.For example, if said platform is twin-channel platform, but it has 38 channel of operation, and step S203 promptly checks the scanning of whether accomplishing said 38 channels.If accomplished all scan channels, indication begins scanning from initial channel in step S204 so, like channel 1.Said initial scanning channel can be along with the platform of different operating frequency and the different setting of user and difference to some extent.The platform of the platform of 2.4GHz and 5GHz for example, its initial scanning channel is respectively channel 1 and channel 36.If in step S202, only accomplish the sweep test channel, as only accomplishing channel 1 scanning work to channel 108, the once last in the past channel of accomplishing scanning of the indication scanning that continues in step S205 so promptly begins to scan from channel 112.Scanning channel 112 in step S206.

The detailed step of Fig. 3 step display S206.In step S301, set a channel to be scanned, like above-mentioned channel 112.In step S302, judge the scanning record that whether contains channel 112 in the said scan channel record.If, the said scanning record of deletion in step S303 so.Said scanning record comprises the information of the access point that uses channel 112.If not, so in step S304 with active scan mode or passive type scan mode scanning channel 112.Yet, if access point for hiding access point (hidden AP), need use effective service setting identifier (service set identifier) can obtain the information of said hiding access point with active scan mode scanning so.Therefore, in step S305, said platform uses effective service setting identifier to carry out active scanning.

In step S207, channel 112 is recorded as the channel of last scanning.In step S208, judge whether this flow process is interrupted.The those skilled in the art can understand, and this interruption possibly issued (issue) by operating system, or puts the said gradual scanning flow process of interruption at any time by the user.If have the situation of interruption to take place, finish said gradual scanning flow process so.If, in step S209, do not judge whether to be last channel to be scanned so.If, do not get back to scanning channel next to be scanned among the step S206 so.If in step S210, finish said progressive channel scanning flow process so.From the above mentioned, the those skilled in the art can understand, and progressive channel scanning method of the present invention can solve because delete the problem that can't accomplish all scan channels that all scanning records are caused before the scanning constant time of operating system and the scanning.In addition, platform uses effective service setting identifier to carry out active scanning has also increased the chance that obtains the information of hiding access point.

In order to make the those skilled in the art come embodiment of the present invention through this instruction of implementing example, below the above-mentioned progressive channel scanning method of collocation proposes the enforcement example of a progressive channel scanning device in addition.

Fig. 4 describes of the present invention another and implements the block diagram of the progressive channel scanning device of example.Progressive channel scanning device 400 comprises setup unit 401, scanning element 402, record cell 403, inspection unit 404 and delete cells 405.Setup unit 401 is in order to set channel to be scanned.Scanning element 402 is in order to scanning said channel to be scanned, and sets with active scan mode operation still with the passive type scan mode operation.If access point need use effective service setting identifier so for hiding access point, and scan the information that just can obtain said hiding access point with active scan mode.Therefore, scanning element 402 also uses effective service setting identifier to scan said channel to be scanned with active scan mode.The said channel record that record cell 403 just will be accomplished scanning in order to every completion one scan channel in the scanning element scanning process is last scanning channel, and at least one scanning result in the said scanning element is published in the scanning record.Inspection unit 404 is in order to the scanning result of checking said record cell and determine next channel to be scanned.If wherein said next channel is a K+1 channel when under 2.4GHz, scanning, if when said next channel scans under 5GHz then be K+4 channel, or the next channel that support is arranged.Delete cells 405 is in order to the scanning result of the said channel to be scanned of single pass before deleting in the said scanning record.For example, setup unit 401 is set at channel to be scanned with channel 112, if store the scanning result of a preceding scanning channel 112 in the record cell 403, before this scanning channel 112, deletes the scanning result of a preceding scanning channel 112 so earlier.The present invention implements wherein a kind of mode that the wireless channel scanning device 400 of example can software realizes, realizes, on the platform of embedded single-processor or multiprocessor, realizes with hardware and realizes.

In sum, whether single pass accomplished all scan channel work before progressive channel scanning method and apparatus of the present invention was judged earlier.If start anew to scan and before scanning one channel, delete the preceding scanning result of channel described in the sweep record so.To be about to said channel record be last scanning channel to every completion one scan channel in the scanning process.If the preceding local channel scanning work of once only accomplishing is so from the scanning that begins to continue of last scanning channel.In addition, for lifting obtains the chance of hiding access-in point information, also use effective service setting identifier with active scan mode scanning channel.

Technology contents of the present invention and technical characterstic disclose as above, yet the those skilled in the art still maybe be based on teaching of the present invention and disclosure and done all replacement and modifications that does not deviate from spirit of the present invention.Therefore, protection scope of the present invention should be not limited to implement the content that example discloses, and should comprise various do not deviate from replacement of the present invention and modifications, and is contained by above claims.

Claims (15)

1. A method for progressive channel scanning, characterized in that it comprises: Check whether the channel scanning procedure is completed and obtain a scanning instruction; wherein, during the scanning process, each time a channel scanning is completed, the channel will be recorded as the last scanning channel; and when the channel scanning procedure is not completed, the scanning instruction is used to indicate to continue the last Scan channel to continue scanning; setting a channel to be scanned according to the scanning instruction; If the information of the channel to be scanned exists in the scan record, then delete the information of the channel to be scanned from the scan record; and Scan the channel to be scanned. 2. The method of claim 1, wherein the scanning the channel to be scanned comprises scanning the channel to be scanned in an active scanning manner using a valid service configuration identifier. 3. The method of claim 1, further comprising recording the channel to be scanned as the last scanned channel. 4. The method according to claim 1, wherein said setting the channel to be scanned step comprises: If the scanning of N channels to be scanned has been completed, start scanning from the first channel, where N is an integer; and If only K channels to be scanned among the N channels to be scanned are scanned, start scanning from the next channel, where K is an integer. 5. The method according to claim 4, wherein the N channels to be scanned are channels on which the station can operate. 6. The method according to claim 4, wherein the next channel is the K+1th channel if it is scanned at 2.4GHz, and the next channel is the K+1th channel if it is scanned at 5GHz. The K+4th channel, or the next supported channel. 7. The method according to claim 1, wherein the method of scanning the channel to be scanned is active scanning. 8. The method according to claim 1, wherein the method of scanning the channel to be scanned is passive scanning. 9. A device for progressive channel scanning, characterized in that it comprises: a setting unit, which is used to set the channel to be scanned; a scanning unit, configured to scan the channel to be scanned; A recording unit, which is used to record the scanned channel as the last scanned channel every time a channel scan is completed during the scanning unit scanning process, and to record at least one scanning result in the scanning unit in the scanning record; and The checking unit is configured to check the at least one scanning result in the recording unit and determine the next channel to be scanned, wherein the next channel to be scanned is the continuation of the last scanned channel. 10 . The device according to claim 9 , further comprising a deletion unit configured to delete the at least one scan result in the scan record. 11 . 11. The device according to claim 10, wherein the deleting unit deletes the scanning result of the previous scan of the channel to be scanned in the recording unit. 12. The device according to claim 9, wherein the scanning unit uses a valid service configuration identifier to scan the channel to be scanned in an active scanning manner. 13. The device of claim 9, wherein the scanning unit is configured to operate in an active scanning mode. 14. The device of claim 9, wherein the scanning unit is configured to operate in a passive scanning mode. 15. The device according to claim 9, characterized in that it is implemented in software, in hardware, or on a platform embedded with a single processor or multiple processors.

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