KR100745611B1 - Method for searching the channels to access in wireless LAN card - Google Patents

Abstract

The present invention provides a channel searching method that can more accurately and quickly search for a channel for accessing a WLAN card to an AP.

The channel search method according to the present invention is a method for searching for a channel for accessing an AP in a WLAN card existing in a WLAN service area in which at least one access point (AP) is installed. Here, the AP is constructed using at least one of a single channel, a first channel bundle including a specific number of channels that can be used without frequency interference, and a second channel bundle including a maximum number of channels to avoid frequency interference as much as possible. . First, a search request packet is transmitted for a single channel, and the reception waiting time of the search response packet for the search request packet is set as the first time. Next, a search request packet is sequentially transmitted to each channel belonging to the first channel bundle, and a reception wait time for the search request packet is set to the first time. In this way, it is determined whether a search response packet is received while the search request packet is transmitted, and when the search response packet is received, the search request packet is sequentially transmitted to each channel belonging to the second channel bundle, and the second shorter than the first time. Set waiting time for search request packet by time.

Channel, WLAN card, AP, Reception standby

Description

Method for searching the channels to access in wireless LAN card}

1 is a view showing in order a specific example of a channel search method performed in a wireless LAN card according to a first embodiment of the present invention.

2 is a view showing in order a specific example of a channel search method performed in a wireless LAN card according to a second embodiment of the present invention.

The present invention relates to a channel search method performed in a WLAN card, and more particularly, to a channel search method capable of shortening a channel search time in a WLAN card.

In general, the method of accessing a wireless LAN card includes an ad-hoc method for accessing a wireless LAN through 1: 1 communication between terminals and all terminals through an access point (AP) according to a network configuration. It is divided into the infrastructure method to connect.

In the conventional wireless LAN access method, SSID (subsystem identification) is set in AP, which is each WLAN node, SSID is set in WLAN card of user terminal, and communication is performed between WLAN card and AP of user terminal having the same SSID. Let it go.

Here, in order to access the AP of a specific SSID in the WLAN card, the search request packet is transmitted to the corresponding SSID in a channel order specified without a specific meaning for each manufacturer. In addition, the same time for each channel is allocated to the waiting time for receiving the search response packet sent from the AP in each channel.

As described above, there is a problem in that the efficiency of the search is significantly lowered by transmitting the search request packets in the designated channel order regardless of the characteristics of each AP or the channel condition, and by allocating the same waiting time for receiving the search response packet.

Therefore, there is an urgent need for a method for more efficiently searching for an AP in a WLAN card.

The technical problem to be achieved by the present invention is to provide a channel search method that can more accurately and quickly search for a channel for accessing the WLAN card AP.

A channel searching method according to an aspect of the present invention is a method for searching for a channel for accessing an AP in a WLAN card existing in a WLAN service area in which at least one access point (AP) is installed.

The AP is built utilizing at least one of a single channel, a first channel bundle comprising a certain number of channels available without frequency interference, and a second channel bundle comprising a maximum number of channels to avoid frequency interference as much as possible. ,                     

a) transmitting a search request packet for a single channel and setting a reception waiting time of a search response packet for the search request packet as a first time;

b) sequentially transmitting a search request packet for each channel belonging to the first channel bundle and setting a reception wait time for the search request packet to the first time;

c) determining whether a search response packet is received while the search request packet is being transmitted; And

d) when the search response packet is received, sequentially transmits a search request packet for each channel belonging to the second channel bundle and sets a reception waiting time for the search request packet at a second time shorter than the first time. Setting up.

The specific number may be three, and the maximum number may be four.

In step c), if the search response packet is not received, e) sequentially transmitting a search request packet for each channel belonging to the second channel bundle, and receiving reception time for the search request packet at the first time. It may further comprise the step of setting.

There is at least one channel bundle that is compatible with the first channel bundle,

After step b), b-1) sequentially transmitting search request packets for channels belonging to at least one channel bundle that can be mixed with the first channel bundle and receiving waiting time for the search request packets with the first time. It may further comprise the step of setting.                     

There is at least one channel bundle that is compatible with the second channel bundle,

After step d), d-1) sequentially transmits a search request packet for a channel belonging to at least one channel bundle that can be mixed with the second channel bundle and receives a waiting time for the search request packet at the second time. It may further comprise the step of setting.

There is at least one channel not included in the first and second channel bundles, and after step d), f) a search request is sequentially performed for at least one channel not included in the first and second channel bundles. The method may further include transmitting a packet and setting a reception waiting time for the search request packet as the second time.

According to another aspect of the present invention, a channel searching method is a method of searching for a channel to access an AP in a WLAN card existing in a WLAN service area in which at least one access point (AP) is installed.

The WLAN card operates through at least one band and at least one Media Access Control (MAC) and PHY (PHYsical) in each band,

A first combination comprising a band, a MAC, and a PHY for accessing the WLAN card to the AP, a second combination that can be mixed with the first combination, and a third combination that cannot be mixed with the first combination,

a) transmitting a search request packet for the first combination, and setting a reception waiting time of the search response packet for the search request packet to a first time;

b) transmitting a search request packet for the second combination and setting a reception waiting time of the search response packet for the search request packet to a first time;

c) determining whether a search response packet is received while the search request packet is being transmitted; And

d) when the search response packet is received, sequentially transmitting search request packets for the third combination and setting a reception waiting time for the search request packets at a second time shorter than the first time. do.

The WLAN card can operate at 2.4 GHz and 5 GHz, respectively.

The first combination may include a 2.4 GHz ISM band, and the second combination may include any one of a 5 GHz ISM subband and a 5 GHz UNII A band.

The third combination may include any one of 5GHz UNII B and 5GHz UNII C bands.

C) if the search response packet is not received in step c), e) transmitting search request packets sequentially for the third combination and setting a reception waiting time for the search request packets as the first time; It may further include.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.                     

First, a channel search method performed in a WLAN card according to a first embodiment of the present invention will be described in detail.

In the channel searching method performed in the WLAN card according to the first embodiment of the present invention, in order to efficiently use a specific channel order in which the AP is most installed and a limited channel, the channel group first determines the order of channels to be searched by the WLAN card. By increasing the reception wait time on the channel where the AP is expected to be installed or by shortening the reception wait time on the channel that is not installed, the AP can be searched more accurately and quickly for the corresponding WLAN AP access service or the overall WLAN It makes the search time of AP shorter.

There are 13 channels that can be used in Korea for the wireless LAN operating at 2.4GHz. However, there are three channels with enough independent channels without inter-frequency interference, and the number of channels that can be utilized as much as possible to avoid the channel interference is four.

In case of installing AP for wireless LAN service, in case of installing AP in a specific area by applying this concept, it defines a specific channel to be set up when only one AP is installed alone, and installs several APs to establish a wireless LAN service area. In case of configuration, up to 4 channels can be used in 3 channels. When installing a single AP, the channels used are 3 independent channel bundles or 4 independent channel bundles.

For example, if a channel that can be used in Korea is numbered from 13 to 13 channels, the 13 channels can be bundled into a specific group. The single channel becomes [1], and the three independent channel bundles use [1,6,11] including the single channel, and the four independent channel bundles include the single channel but belong to three independent channel bundles. [1, 5, 9, 13] can be used to avoid duplication. And three independent channel bundles and four independent channel bundles cannot be mixed with each other. This channel group can be determined when the AP is installed.

According to the channel search method in a wireless LAN card for one band, the search is performed in the following principle.

First, the WLAN card preferentially searches for a single channel, and at this time, the reception waiting time is set to a relatively long time interval.

Secondly, when establishing a WLAN service zone by installing several APs, the WLAN card searches for independent channel bundles. At this time, the reception wait time is set to a relatively long time interval.

Third, when there are a plurality of independent channel bundles, channels belonging to the channel bundles having priority are first searched according to the policy decision of the corresponding WLAN service. For example, there may be a plurality of three independent channel bundles that can be mixed, such as [1, 6, 11], [2, 7, 12], and [3, 8, 13]. In this case, a plurality of independent channel bundles that can be mixed are called a bundle, and among the independent channel bundles belonging to the bundle, channels belonging to [1, 6, 11], which are independent channel bundles having priority according to the WLAN service policy decision. Search them sequentially first.

Fourth, after the search for one independent channel bundle in the bundle is prioritized, all other intermixable independent channel bundles in sequence, such as [2, 7, 12], [3, 8, 13] ] Can be searched sequentially. At this time, the reception wait time for the transmission of the search request packet until all the independent independent channel bundles that can be mixed are set to a relatively long time.

Fifth, when this completes the search for all independent channel bundles belonging to one bundle, an exclusive independent channel bundle that cannot be mixed with the independent channel bundles belonging to the bundle described above, such as four independent channel bundles [1, 5, 9, 13] to search for channels belonging to. At this time, the reception wait time for transmission of the search request packet is set to a relatively long time.

Sixth, while receiving a search response for the transmitted search request packet while the search for all the bundles of independent channel bundles so far, the reception latency of the remaining intermixable channel bundle bundles is relatively Set at short time interval.

After the search of the bundles of all compatible independent channel bundles is completed, the remaining channels that do not form the independent channel bundle are searched, and the reception wait time is set to a relatively short time interval.

In this way, the WLAN card determines the order of channels to be searched, and the reception wait time in the channel where the AP is expected to be installed is a long time, and the reception wait time in a channel that is not otherwise is short time (short time). In this case, the AP can be searched more accurately and quickly for the WLAN AP access service, and the AP search time of the entire WLAN card can be shortened.

1 is a view showing in order a specific example of a channel search method performed in a wireless LAN card according to a first embodiment of the present invention.

When independent channel bundle A indicates three independent channels among 2.4 GHz WLAN channels, and independent channel bundle B indicates four independent channels among 2.4 GHz WLAN channels, the above search method is applied. . In this case, the mixed bundle of independent channel bundles is composed of one independent channel bundle.

As shown in FIG. 1, the WLAN transmits a search request packet with respect to a single channel (S100), that is, a search for channel [1] is performed first. At this time, the reception wait time is set to a relatively long time.

Next, if the next channel of the single channel among the group A channels, for example, the group A channel is [1, 6, 11], the WLAN card transmits a search request packet with respect to channel 6 (S110). At this time, the waiting time is set as a relatively long time interval.

Then, a search request packet is transmitted to channel 11 which is the last channel of group A (S120). At this time, the waiting time is set as a relatively long time interval.

After the search for the entire group A is completed, it is determined whether a search response packet is received while searching for the channel (S130).

Here, when the search response packet is not received, the search for the next group B independent channel bundle is performed sequentially. First, when the next channel of the single channel, for example, the group B independent channel bundle among the channels belonging to the group B independent channel bundle is [1, 5, 9, 13], the WLAN card transmits a search request packet for channel 5 ( S141). Since the WLAN card has not yet received the search response packet for the search request packet, the waiting time is set to a relatively long time interval.

Next, the search request packet is sequentially transmitted to the remaining channels 9 and 13 of the group B independent channel bundle [1, 5, 9, 13] (S142 and S143).

On the other hand, if a search response packet is received while searching for a channel, the search for the next group B independent channel bundle is performed sequentially. At this time, since the WLAN card has already received the search response packet for the search request packet, the waiting time is set to a relatively short time (S151, S152, S153).

In this way, when the channel search is completed by transmitting a channel search request packet for each of the channels belonging to the group A and group B independent channel bundles, the search is performed on the remaining channels not belonging to each independent channel bundle. For example, the group A independent channel bundle is [1, 6, 11], and the group B independent channel bundle is [1, 5, 9, 13], and thus the remaining channels [2, 3, 4, 7, 8, 10, 12]. Forwards the search request packets for]. At this time, the reception wait time is set to a relatively short time (S160).

Next, a channel search method performed in a WLAN card according to a second embodiment of the present invention will be described.

The second embodiment of the present invention is a channel searching method performed by a WLAN card when the WLAN card operates over multiple bands or when a WLAN card operates in a completely different MAC (Media Access Control) and PHY (PHYsical). Specifically, the WLAN card can operate in multiple bands in function, but at a moment can operate only with MAC and PHY corresponding to one band, and can operate with completely different MAC and PHY in one band, but only one at a time. This is a search method for the case of operating only with MAC and PHY.

Also in this case, as in the first embodiment of the present invention, there are combinations of bands, MACs, and PHYs, and there are combinations that require searching first among the combinations, and there are combinations that can be mixed between the combinations.

In particular, the public WLAN access service is already commercialized for the universal WLAN card that can operate in the 2.4 GHz and 5 GHz bands, and access to the 2.4 GHz AP that is widely spread may be prioritized.

Therefore, the band that needs to be searched first is the 2.4 GHz band, and it can be mixed with the wide band of the 5 GHz band. For convenience, the 5 GHz wide band is divided into upper band ISM and four bands of middle or lower band, UNII A, UNII B, and UNII C, which may not be mixed. In this case, it is not absolutely impossible to be mixed, but in case of establishing a WLAN access service zone with multiple APs, a policy of establishing 5GHz APs of one subband is determined. In this case, of course, it is possible to mix 5GHz ISM bands with other UNII subbands.

In the second embodiment of the present invention, a search method performed by a WLAN card between combinations as in the above-described search method for a WLAN card in one band is as follows.

First, search for a combination of band, MAC and PHY to be accessed first. At this time, the reception wait time is set to a relatively long time interval.                     

Second, the next combination that can be mixed with the combination to be accessed first is searched, and the search order is set according to the priority of the combinations. At this time, the reception wait time is set to a relatively long time interval.

Third, when the search response is received until the search for the combination bundle that can be mixed is completed, the reception waiting time of the search for the combination that is not allowed to be mixed is set to a relatively short time interval.

Fourth, in the case of receiving a search response while searching for a combination bundle that cannot be mixed according to priority, the reception waiting time of the search of the combination that cannot be mixed remaining is set to a relatively short time interval.

FIG. 2 is a diagram illustrating a specific example of a channel searching method performed in a WLAN card according to a second embodiment of the present invention in order.

In FIG. 2, a combination to be preferentially connected to a wireless LAN card capable of operating at 2.4 GHz and 5 GHz is a 2.4 GHz ISM band, and a combination compatible with the combination is a 5 GHz ISM subband and a 5 GHz UNII A band according to priority. The remaining 5 GHz UNII B and 5 GHz UNII C bands are diagrams showing search methods in order when they cannot be mixed with the 5 GHz UNII A band. At this time, it is assumed that 5GHz UNII A, 5GHz UNII B, and 5GHz UNII C are all subbands that cannot be mutually exclusively mixed with each other.

First, the channel search request packet within the highest priority combination is transmitted. At this time, the reception wait time is set to a relatively long time (S200).

Next, the channel search request packet in the next priority combination that can be mixed with the highest priority combination is transmitted. At this time, the reception wait time is set to a relatively long time (S210).

Next, the channel search request packet is transmitted within the last priority combination that can be mixed with the highest priority combination. At this time, the reception wait time is set to a relatively long time (S210).

After transmitting the search request packets sequentially from the highest priority combination as described above, it is determined whether or not to receive the search response packet for the search request packet during the channel search (S230).

When the search response packet is received, the channel search request packet in the bundle that cannot be mixed is transmitted, and the reception waiting time at this time is set to a relatively short time (S240).

On the other hand, when the search response packet is not received, the channel search request packet in the incompatibility combination bundle is transmitted, and the reception waiting time at this time is set to a relatively long time (S251).

If a search response packet is received during the channel search in the incompatibility bundle bundle (S252), the channel search request packet in the incompatibility bundle bundle is transmitted, and the reception wait time is set to a relatively short time (S240). ).

If the search response packet is still not received during the channel search in the non-mixable combination bundle (S252), the channel search request packet in the non-mixable combination bundle is transmitted, and the reception wait time at this time continues with a relatively long time. (S253).

In the present invention described above, if an AP that satisfies a condition within an allowable value for the threshold is selected by selecting a threshold of a specific parameter that can mainly affect the AP access quality, the search is terminated and the AP is terminated. You can use the connection method. This may be a useful method when updating the search information and performing a quick access when there is no AP currently searched. The parameters that can affect the AP connection quality in the actual environment may mainly be signal strength or signal to noise ratio (SNR), and the threshold setting may be set for only one parameter. Can be determined by combination.

Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various other changes and modifications are possible.

According to the present invention, a channel group is formed as an independent channel bundle and a search request packet is transmitted in order to search for a channel group with priority first, and the reception wait time for the search request packet is set to a relatively long time. do. Then, a search response packet for the search request packet is received, and then the reception wait time for the search request packet is set to a relatively short time.

   In this way, the reception waiting time can be set differently according to the channel, so that the channel search can be performed more accurately and quickly.

Claims (11)

A method of searching for a channel for accessing an AP in a WLAN card existing in a WLAN service area in which at least one access point is installed, The AP is built utilizing at least one of a single channel, a first channel bundle comprising a certain number of channels available without frequency interference, and a second channel bundle comprising a maximum number of channels to avoid frequency interference as much as possible. , a) transmitting a search request packet for a single channel and setting a reception waiting time of a search response packet for the search request packet as a first time; b) sequentially transmitting a search request packet for each channel belonging to the first channel bundle and setting a reception wait time for the search request packet to the first time; c) determining whether a search response packet is received while the search request packet is being transmitted; And d) when the search response packet is received, sequentially transmits a search request packet for each channel belonging to the second channel bundle and sets a reception waiting time for the search request packet at a second time shorter than the first time. Steps to set up Channel search method comprising a. The method of claim 1, Wherein the specific number is three and the maximum number is four. The method of claim 1, If the search response packet is not received in step c), e) sequentially transmitting search request packets for each channel belonging to the second channel bundle and setting a reception waiting time for the search request packet as the first time; Channel search method further comprising. The method of claim 1, There is at least one channel bundle that is compatible with the first channel bundle, After step b), b-1) sequentially transmitting a search request packet for a channel belonging to at least one channel bundle that can be mixed with the first channel bundle and setting a reception waiting time for the search request packet as the first time Channel search method further comprising. The method of claim 1, There is at least one channel bundle that is compatible with the second channel bundle, After step d), d-1) sequentially transmitting a search request packet for a channel belonging to at least one channel bundle that can be mixed with the second channel bundle and setting a reception waiting time for the search request packet as the second time Channel search method further comprising. The method of claim 1, There is at least one channel not included in the first and second channel bundles, After step d), f) sequentially transmitting search request packets for at least one channel not included in the first and second channel bundles, and setting a reception waiting time for the search request packets as the second time; Channel search method further comprising. A method for discovering an AP to access an AP in a WLAN card existing in a WLAN service area in which at least one access point is installed, The WLAN card operates through at least one band and at least one Media Access Control (MAC) and PHY (PHYsical) in each band, A first combination comprising a band, a MAC, and a PHY for accessing the WLAN card to the AP, a second combination that can be mixed with the first combination, and a third combination that cannot be mixed with the first combination, a) transmitting a search request packet for the first combination, and setting a reception waiting time of the search response packet for the search request packet to a first time; b) transmitting a search request packet for the second combination and setting a reception waiting time of the search response packet for the search request packet to a first time; c) determining whether a search response packet is received while the search request packet is being transmitted; And d) when the search response packet is received, sequentially transmitting search request packets for the third combination and setting a reception waiting time for the search request packet at a second time shorter than the first time; Channel search method comprising a. The method of claim 7, wherein The WLAN card is a channel search method capable of operating at 2.4GHz and 5GHz respectively. The method of claim 8, Wherein the first combination comprises a 2.4 GHz ISM band and the second combination comprises any one of a 5 GHz ISM subband and a 5 GHz UNII A band. The method of claim 9, And the third combination comprises any one of 5 GHz UNII B and 5 GHz UNII C bands. The method of claim 7, wherein If the search response packet is not received in step c), e) sequentially transmitting search request packets for the third combination and setting a reception waiting time for the search request packets as the first time; Channel search method further comprising.

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