JP2008172555A - Radio lan system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the mismatching of the security mode of a radio LAN and a privacy bit. <P>SOLUTION: An STA_A1 performs SSID retraction notification to an STA_A2 in an unauthorized state, where a security mode does not match a security bit (S601). When the SSID retraction notification is received from the STA_A1, the STA_A2 starts up a new communication segment as a creator (S632). The STA_A1 performs a change to an SSID for retraction before scanning with an old SSID (S612), and joins the communication segment of the STA_A2 started as the creator as a joiner (S620). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless LAN, and more particularly to a technique for avoiding a mismatch between a security mode and a privacy bit.

A wireless LAN has security mode and privacy bit settings for communication security. As the security mode, a “WEP” state in which encryption with a WEP key is performed and a “NoneWEP” state in which encryption with a WEP key is not performed can be taken. The privacy bit includes an “ON” state when encryption with the WEP key is performed and an “OFF” state when encryption with the WEP key is not performed. The security mode and privacy bit settings are usually the same. That is, when the security mode is “WEP”, the privacy bit is “ON”, and when the security mode is “NoneWEP”, the privacy bit is “OFF”.
JP 2006-60578 A

  However, in certain types of wireless communication devices (hereinafter referred to as type A) that perform communication by wireless LAN, inconsistencies in security mode and privacy bit may occur. That is, the privacy bit may be “OFF” when the security mode is “WEP”, and the privacy bit may be “ON” when the security mode is “NoneWEP”. When such a mismatch occurs, the wireless communication device cannot communicate normally.

  A specific mismatch pattern will be described with reference to the drawings.

  FIG. 5 shows a first mismatch pattern.

  First, a wireless communication apparatus STA_A of type A and a wireless communication apparatus STA_B of type B different from type A are communicating in the ad hoc mode with the security mode “NoneWEP” and the privacy bit “OFF”.

  At this time, when the STA_A receives an instruction from the user to switch the security mode to “WEP”, the STA_A starts connection processing with “WEP” (S101). That is, STA_A transmits a probe request 201 and receives a probe response 202 from STA_B. At this time, the probe response 202 includes the setting of the privacy bit of STA_B at this time. That is, the probe response 202 includes information indicating the privacy bit “OFF”.

  When the STA_A confirms that there is no existing communication segment of the security mode “WEP” based on the probe response 202, the STA_A starts up a new communication segment of the security mode “WEP” using itself as a creator (S110). Specifically, the privacy bit of the new communication segment is set to “OFF” by copying the privacy bit included in the probe response 202 to the privacy bit of STA_A (S111). Further, the security mode of STA_A is set to “WEP” (S112). At this time, the STA_A detects that the security mode and the privacy bit are inconsistent, and sets an invalid BSSID (all F) in the BSSID that is the identification information of the new communication segment (S113).

  The cause of this inconsistency is that, in step S111, STA_A copies the privacy bit included in the probe response 202 as it is as the privacy bit of the new communication segment.

  On the other hand, when the STA_B receives an instruction to switch the security mode to “WEP” from the user, the STA_B also starts connection processing using “WEP” (S301). That is, STA_B also sends a probe request 203 and receives a probe response 204 from STA_A. At this time, the probe response 204 includes the setting of the privacy bit of STA_A at this time. That is, the probe response 204 includes information indicating the privacy bit “OFF”.

  Here, when the STA_B confirms that there is no existing communication segment in the security mode “WEP” based on the probe response 204, the STA_B starts up a new communication segment in the security mode “WEP” using itself as a creator (S310). ). A specific process at that time is to set the privacy bit to “ON” corresponding to the security mode “WEP” (S311). Further, the security mode of STA_B is set to “WEP” (S312). At this time, since the security mode and the privacy bit are consistent, a normal BSSID (MAC address of STA_B) is set in the BSSID that is the identification information of the new communication segment (S313).

  Thereby, STA_B starts a new communication segment of the security mode “WEP” as a creator.

  However, according to the above processing, inconsistency between the security mode and the privacy bit occurs in STA_A, and STA_A and STA_B cannot communicate with each other.

  FIG. 6 shows a second mismatch pattern. This pattern is obtained when the type A wireless LAN communication apparatus STA_A and the type B wireless LAN communication apparatus STA_B are communicating in the ad hoc mode with the security mode “WEP” and the privacy bit “ON”. This occurs when switching to the security mode “NoneWEP”.

  Also in this case, as in the first mismatch pattern, STA_A copies the privacy bit included in the probe response 212 as it is as the privacy bit of the new communication segment (S121). As a result, similarly to the first inconsistency pattern, inconsistency between the security mode and the privacy bit occurs, and STA_A and STA_B cannot communicate with each other.

  FIG. 7 shows a third mismatch pattern. This pattern indicates that when the wireless LAN communication apparatuses STA_A of type A (STA_A1, STA_A2) are communicating in the ad hoc mode with the security mode “WEP” and the privacy bit “ON”, the security mode “NoneWEP” Occurs when switching to "."

  Also in this case, as in the first and second mismatch patterns, STA_A1 and STA_A2 copy the privacy bits included in the probe responses 222 and 224 as they are as the privacy bits of the new communication segment. (S131, S141). This causes a mismatch between the security mode and the privacy bit, as in the first and second mismatch patterns. As a result, although STA_A1 and STA_A2 cannot perform normal communication with each other, both BSSIDs share an incorrect value (all F), so communication is established at the IP level.

  Therefore, an object of the present invention is to avoid inconsistency between the security mode and privacy bit of the wireless LAN as described above.

  In the wireless LAN system according to an embodiment of the present invention, the first wireless communication device and the second wireless communication device perform wireless LAN communication in the ad hoc mode according to the security mode and the security bit. The first wireless communication device accepts a predetermined notification from the second wireless communication device when the first wireless communication device and the second wireless communication device are communicating with the first SSID. And a startup means for starting a new communication segment as a creator with the first SSID. The second wireless communication device includes means for notifying the first wireless communication device of the predetermined notification when the security mode and the security bit are in an inaccurate state, and the security mode and the security bit are A means for setting its own SSID to a second SSID different from the first SSID in the case of an illegal state that does not match, and a second SSID is set and then activated as a creator based on the predetermined notification A second wireless communication device that detects the second wireless communication device and adds the SSID to the first SSID and joins the new communication segment as a joiner.

  In the wireless LAN system according to an embodiment of the present invention, the first wireless communication device and the second wireless communication device perform wireless LAN communication in the ad hoc mode according to the security mode and the security bit. The first wireless communication device is in an illegal state in which the security mode and the security bit do not match when the first wireless communication device and the second wireless communication device are communicating with the first SSID. If so, it comprises means for notifying the second wireless communication apparatus with the predetermined notification, and starting means for starting up a new communication segment as a creator with the first SSID. The second wireless communication device, based on the predetermined notification from the first wireless communication device, sets its own SSID to a second SSID different from the first SSID; After setting the SSID of 2, when the second wireless communication device activated as the creator of the new communication segment is detected, the SSID is returned to the first SSID and added to the new communication segment as a joiner. Means.

  Hereinafter, a wireless LAN communication system according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration of a wireless LAN system according to the present embodiment. That is, this system includes a plurality of wireless communication devices, and each wireless communication device performs ad hoc communication over a wireless LAN. These wireless communication apparatuses may be incorporated in some information processing apparatus.
In addition, the wireless communication devices shown in the figure include different types of wireless communication devices, that is, a type A wireless communication device 10 (STA_A) and a type B wireless communication device 60 (STA_B). The basic configurations of the wireless communication devices 10 and 60 are common, and the individual operations of each component described below are partly different.

  First, a common configuration of the wireless communication devices 10 and 60 will be described.

  Each of the wireless communication devices 10 and 60 includes wireless LAN communication devices 20 and 70 and communication control units 30 and 80.

  Each of the wireless LAN communication devices 20 and 60 is realized by, for example, a wireless LAN semiconductor chip and firmware for controlling the semiconductor chip. Each of the wireless LAN communication devices 20 and 60 functionally includes communication processing units 21 and 71, communication setting units 22 and 72, WEP modules 23 and 73, and BSSID management units 24 and 74.

  The communication processing units 21 and 71 communicate with each other according to wireless LAN specifications.

  The communication setting units 22 and 72 perform settings necessary for wireless LAN communication. For example, the communication setting units 22 and 72 set a security mode and a privacy bit.

  The WEP modules 23 and 73 store the WEP key and perform encryption and decryption processing using the WEP key.

  The BSSID management units 24 and 74 manage BSSIDs for identifying communication segments.

  The communication control units 30 and 80 are realized by, for example, predetermined software or a combination of predetermined software and hardware. Functionally, the communication control units 30 and 80 include storage units 31 and 81, processing units 32 and 82, and interfaces 33 and 83, respectively.

  The storage units 31 and 81 store information input from a user interface (not shown) included in the wireless communication devices 10 and 60. For example, information indicating a security mode desired by the user is stored.

  The processing units 32 and 82 issue various commands to the wireless LAN communication devices 20 and 70 and execute processing for controlling the wireless LAN communication devices 20 and 70. For example, the processing units 32 and 82 generate a command for instructing connection in a user-desired security mode stored in the storage units 31 and 81, and send the command to the wireless LAN communication devices 20 and 60.

  The interfaces 33 and 83 are interfaces for sending commands to the wireless LAN communication devices 20 and 70 or acquiring various information from the wireless LAN communication devices 20 and 70.

  FIG. 2 is a sequence chart of the security mode switching process according to the present embodiment.

  First, the type A wireless communication device 10 (hereinafter referred to as STA_A) and the type B wireless LAN communication device 60 (hereinafter referred to as STA_B) have the security mode “NoneWEP” and the privacy bit is “OFF”. Communicating in ad hoc mode.

  At this time, when STA_A receives an instruction from the user to switch the security mode to “WEP”, the processing unit 32 sends a WEP connection start command to the wireless LAN communication device 20. Upon receiving this, the wireless LAN communication device 20 starts connection processing in the security mode “WEP” (S101).

  That is, the wireless LAN communication device 20 transmits a probe request 201 and receives a probe response 202 from the wireless LAN communication device 70. Further, when it is confirmed that there is no communication segment of the security mode “WEP” based on the probe response 202, the creator activation process shown in FIG. 5 is performed (S110). In the creator activation process in step S110, the BSSID management unit 24 generates an invalid BSSID.

  On the other hand, the wireless communication device 60 also receives an instruction from the user to switch the security mode to “WEP”, and the processing unit 82 sends a WEP connection start command to the wireless LAN communication device 70. Upon receiving this, the wireless LAN communication device 70 starts connection processing in the security mode “WEP” (S301).

  That is, the wireless LAN communication device 70 transmits a probe request 203 and receives a probe response 204 from the wireless LAN communication device 20. Further, if it is confirmed that there is no communication segment of the security mode “WEP” based on the probe response 204, the creator activation process shown in FIG. 5 is performed (S310). In the creator activation process in step S310, the BSSID management unit 74 generates a normal BSSID.

  Here, STA_A performs a switching determination process after the creator activation process in step S110 (S500).

  A specific processing procedure of the switching determination processing in step S500 is shown in FIG.

  First, the processing unit 32 checks the BSSID of STA_A at this time (S501). As a result of this check, if the BSSID of STA_A is normal (S501: Yes), this process ends.

  On the other hand, if the BSSID is invalid (S501: No), the processing unit 32 further determines whether or not the wireless LAN communication device 20 has established communication at the IP level (S502). If this IP level communication has not been established (S502: non-connection), the processing unit 32 sends again a connection start command in the security mode desired by the user to the wireless LAN communication device 20, and reconnection processing is performed. Is executed (S505).

  On the other hand, if communication at the IP level has been established (S502: connection), the processing unit 32 sends a command for forced disconnection to the wireless LAN communication device 20 to forcibly disconnect the current connection (S503). Further, the processing unit 32 sends a command for clearing the settings related to the current wireless LAN (S504), and performs step S505.

  In the case shown in FIG. 2, since the BSSID is illegal (S501: No), and communication at the IP level has not been established (S502: not established), the processing unit 32 refers to the storage unit 31 in step S505. After confirming that the user-desired security mode is “WEP”, the WEP connection start command is retransmitted to the wireless LAN communication device 20.

  Thereby, as shown in FIG. 2, STA_A starts reconnection by WEP (S150). That is, STA_A transmits a probe request 205 and receives a probe response 206 from STA_B. At this time, the probe response 206 includes the setting of the privacy bit of STA_A at this time. That is, the probe response 206 includes information indicating the privacy bit “ON”.

  When the STA_A confirms that the wireless communication device 60 has already started the communication segment of the security mode “WEP” as a creator based on the probe response 206, the STA_A joins the communication segment as a joiner (S160). That is, the privacy bit of this probe response 206 is copied to the privacy bit of STA_A (S161). Further, the security mode of STA_A is set to “WEP” (S162). Then, the BSSID management unit 24 copies the BSSID included in the probe response 206 and sets the BSSID of STA_A (S163).

  As a result, the inconsistency between the security mode and the privacy bit generated in STA_A is resolved, and a normal connection can be made. Note that, even when switching from “WEP” to “NoneWEP” shown in FIG. 6, inconsistency between the security mode and the privacy bit can be resolved by the switching determination process.

  In addition, when inconsistency occurs in ad hoc communication between STA_A of type A shown in FIG. 7, when the switching determination process is applied, it is determined in step S502 that IP level communication is established. In step S503, the current communication is forcibly disconnected. In step S540, the wireless LAN setting is cleared, and reconnection is performed in step S505.

  However, in this case, since both STA_A perform these processes, inconsistency between the security mode and the privacy bit may not be eliminated depending on the execution timing. Therefore, if it is determined in step S502 of the switching determination process that a connection in an inconsistent state has been established, a process as shown in FIG. 4 may be performed.

  FIG. 4 is a sequence chart for resolving inconsistency in the security mode switching process between the type A wireless communication apparatuses 10 (STA_A1, STA_A2).

  When the processing unit 32 of the STA_A1 detects the establishment of the connection in the inconsistent state in step S502 of the switching determination process, the STA_A1 notifies the STA_A2 of the SSID save via the wireless LAN communication device 20 (S601). The processing unit 32 of the STA_A1 sends an SSID change command to the wireless LAN communication device 20 after the save notification, and changes its SSID to a save SSID (S611).

  Upon receiving the SSID save notification from STA_A1, STA_A2 returns a response (S602). Then, the processing unit 32 of the STA_A2 retransmits the NoneWEP connection start command to the wireless LAN communication device 20, whereby the STA_A2 starts the connection process using the NoneWEP (S631). That is, STA_A2 transmits a probe request 621, but the probe response is not returned because the SSID of STA_A1 is changed to the evacuation SSID. Therefore, STA_A2 can start up a new communication segment normally as a creator as it is (S632).

  On the other hand, the processing unit 32 of the STA_A1 instructs to scan the communication segment of the old SSID before saving, and the wireless LAN communication device 20 transmits the probe request 262 (S612). Here, if the creator activation process of STA_A2 in step S632 is completed, STA_A2 returns a probe response 263. Based on the probe response 263, the wireless LAN communication apparatus 20 of the STA_A1 executes a process of joining as a joiner to the communication segment started up by the STA_A1 (S620). That is, in the join process as a joiner, the privacy bit is set to “OFF” (S621), and the SSID is returned to the old SSID before saving (S622). Then, the security mode of the STA_A1 is set to “WEP” (S623), and the BSSID management unit 24 copies the BSSID included in the probe response 263 and sets the BSSID of the STA_A1 (S264).

  As a result, the inconsistency between the security mode and the privacy bit generated in the ad hoc communication between the STA_A is resolved, and a normal connection can be established.

  In the example of FIG. 4, the STA_A1 saves the SSID, but the STA_A2 that receives the notification in step S601 may save the SSID. In other words, when STA_A2 receives the notification in step S601, STA_A2 temporarily changes its SSID to an evacuation SSID, STA_A1 starts up a new communication segment as a creator, and STA_A2 joins it as a joiner. Also good.

  The above-described embodiments of the present invention are examples for explaining the present invention, and are not intended to limit the scope of the present invention only to those embodiments. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

1 shows a configuration of a wireless communication LAN system according to an embodiment of the present invention. It is a sequence chart of the security mode switching process concerning this embodiment. A specific processing procedure of the switching determination processing in step S500 is shown in FIG. It is a sequence chart of a security mode switching process between type A wireless communication devices. The 1st mismatch pattern in a prior art is shown. The 2nd mismatch pattern in a prior art is shown. The 3rd mismatch pattern in a prior art is shown.

Explanation of symbols

10, 60 ... wireless communication device, 20, 70 ... wireless LAN communication device, 30, 80 ... communication control unit.

Claims (2)

A wireless LAN system in which the first wireless communication device and the second wireless communication device perform wireless LAN communication in an ad hoc mode according to a security mode and a security bit,
The first wireless communication device is:
When a predetermined notification is received from the second wireless communication device when the first wireless communication device and the second wireless communication device are communicating with the first SSID, the first SSID, As a creator, it has a startup means to launch a new communication segment,
The second wireless communication device is:
Means for notifying the first wireless communication device of the predetermined notification when the security mode and the security bit are in an inconsistent state;
Means for setting its own SSID to a second SSID different from the first SSID when the security mode and a security bit are in an inconsistent state;
After setting the second SSID, when detecting the second wireless communication device activated as a creator based on the predetermined notification, the SSID is returned to the first SSID and the new communication segment is joined as a joiner. A wireless LAN system comprising means for adding. A wireless LAN system in which the first wireless communication device and the second wireless communication device perform wireless LAN communication in an ad hoc mode according to a security mode and a security bit,
The first wireless communication device is:
If the first wireless communication device and the second wireless communication device are communicating with the first SSID and the security mode and the security bit are in an inconsistent state, the second wireless communication device Means for performing the predetermined notification to a communication device;
An activation means for starting up a new communication segment as a creator with the first SSID;
The second wireless communication device is:
Means for setting its own SSID to a second SSID different from the first SSID based on the predetermined notification from the first wireless communication device;
After setting the second SSID, upon detecting the second wireless communication device activated as the creator of the new communication segment, it returns its own SSID to the first SSID and joins the new communication segment to the new communication segment. A wireless LAN system comprising:

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