JP4915301B2 - Wireless LAN system, wireless LAN terminal, and access point - Google Patents

Description

  The present invention relates to a wireless LAN terminal that performs wireless communication based on a wireless LAN standard, an access point, and a wireless LAN system including these.

  Wireless LAN systems based on standards such as IEEE 802.11a and IEEE 802.11b are known. In such a wireless LAN system, there is a method in which each wireless LAN terminal communicates with each other via a relay station called an access point (sometimes abbreviated as AP). In such a system, when the number of wireless LAN terminals that communicate via one access point increases, the communication load generated at the access point by these wireless LAN terminals increases.

  When the communication load of the access point exceeds a value that allows normal communication, a loss of communication data or the like occurs. In such a situation, in the case of communication such as voice communication such as VoIP (Voice over Internet Protocol) or communication that requires a relatively real time property such as streaming distribution of video or the like, retransmission of missing communication data is not performed. Sound and video are interrupted, which is a problem.

  In order to avoid this, for example, Patent Document 1 discloses a technique for distributing the attribution of a terminal device to an appropriate access point according to the load status of each access point. When the wireless LAN terminal belongs to an access point, the wireless system described in the patent document permits the terminal device to belong to the access point if the load on the access point is lighter than a predetermined value. The wireless LAN terminal to which the wireless LAN terminal intends to belong is reported, and the wireless LAN terminal is instructed to belong to a relatively light load among the other access points included in the report.

JP 2004-221684 A

  By the way, in a wireless LAN system, a wireless LAN terminal can be connected to a network by belonging to the nearest access point. However, only when connected to the network, the generated traffic is small, and the communication load of the access point to which the wireless LAN terminal belongs is such that it is generated by control data or the like.

  Here, the wireless system described in Patent Literature 1 may change the access point to which it belongs, depending on the communication load status of the access point at the time of belonging, regardless of whether or not data communication is performed. is there. Usually, a wireless LAN terminal often attempts to belong to an access point with the best received signal quality. For this reason, when the access point to be attributed is changed, the wireless LAN terminal is attributed to an access point having relatively poor received signal quality, even if it is only attributed.

  Generally, the communication load of an access point changes from moment to moment depending on the communication status of other wireless LAN terminals belonging to the access point. For this reason, with the technique described in Patent Document 1, the wireless LAN terminal will be assigned to an access point with relatively poor received signal quality after that because the communication load of the access point exceeds a predetermined value at the time of belonging. .

  In addition, since a general wireless LAN terminal that does not use the technique described in Patent Document 1 usually belongs to an access point with the best received signal quality, it is necessary to maintain a high communication quality at the same access point. Regardless of whether or not there is a LAN terminal, a general wireless LAN terminal may increase the communication load, and a wireless LAN terminal that needs to maintain high communication quality has a relatively poor reception signal quality. There is a possibility that a general wireless LAN terminal belonging to an access point remains in the state of belonging to an access point with relatively good received signal quality. In such a case, a general wireless LAN terminal that does not need to maintain high communication quality belongs to an access point having a relatively good reception signal quality, and a wireless LAN terminal that needs to maintain high communication quality has received signal quality. Since the access point belongs to a relatively poor access point, an inefficient access point is selected for a wireless LAN terminal that needs to maintain high communication quality.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to receive a wireless LAN terminal that can maintain high communication quality and needs to maintain high communication quality, such as a telephone terminal. The purpose is to allow more access points to be assigned to access points with good signal quality.

  In order to solve the above problem, the access point of the present invention checks its own communication load when a wireless LAN terminal belonging to itself and having a high priority starts data communication, and the wireless LAN terminal When the communication quality for the data communication of the wireless LAN terminal cannot be ensured, the communication load necessary for ensuring the communication quality for the data communication of the wireless LAN terminal is a wireless LAN other than the wireless LAN terminal with a high priority. If the error occurs due to the data communication of the terminal, the wireless LAN terminal other than the wireless LAN terminal with high priority is moved to another access point.

  For example, a first aspect of the present invention is a wireless LAN system including a plurality of access points and a plurality of wireless LAN terminals, and each of the plurality of wireless LAN terminals is connected to the access point via the belonging access point. It has terminal side AP information changing means for acquiring identification information and rewriting the identification information held as the belonging access point to the acquired identification information, and each of the plurality of access points belongs to its own access point. Communication start request detecting means for detecting a communication start request of the wireless LAN terminal in the communication, communication end detecting means for detecting the communication end of the wireless LAN terminal belonging to the own access point, and communication occurring at the own access point The communication load detecting means for measuring or calculating the load and the communication start request detecting means belong to the own access point. A communication band securing determination means for determining whether or not the communication bandwidth required by the wireless LAN terminal can be secured from the communication load detected by the communication load detecting means when detecting a communication start request of the line LAN terminal; A terminal detecting means for detecting a wireless LAN terminal existing in the vicinity of the own access point, and acquiring the identification information of the access point from another access point, rewriting the identification information of the own access point to the acquired identification information, and the own access point An AP side AP information changing unit that transmits access point identification information to a wireless LAN terminal or other access point belonging to the wireless LAN terminal is provided.

  According to a second aspect of the present invention, there is provided a wireless LAN terminal used in a wireless LAN system including a plurality of access points, wherein the access point identification information is acquired via the belonging access point, There is provided a wireless LAN terminal characterized by having terminal side AP information changing means for rewriting identification information held as an access point to acquired identification information.

  The third aspect of the present invention is an access point that is used in a wireless LAN system and performs wireless communication with a wireless LAN terminal, and is a communication that detects a communication start request of a wireless LAN terminal belonging to the own access point. A start request detecting means, a communication end detecting means for detecting the end of communication of a wireless LAN terminal belonging to the own access point, a communication load detecting means for measuring or calculating a communication load generated at the own access point, and a communication Whether the communication bandwidth required by the wireless LAN terminal can be secured from the communication load detected by the communication load detecting means when the start request detecting means detects a communication start request of the wireless LAN terminal belonging to the own access point Communication band securing determining means for determining whether or not, and terminal detecting means for detecting a wireless LAN terminal existing in the vicinity of the own access point The access point identification information is acquired from the other access point, the identification information of the own access point is rewritten to the acquired identification information, and the access point identification is assigned to the wireless LAN terminal or other access point belonging to the own access point. There is provided an access point characterized by comprising AP side AP information changing means for transmitting information.

  According to the wireless LAN system of the present invention, the communication quality of the wireless LAN terminal can be kept high, and a wireless LAN terminal that needs to keep the communication quality high like a telephone terminal can be used as an access point with good reception signal quality. Can be attributed more.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of the configuration of a wireless LAN system 10 according to an embodiment of the present invention. The wireless LAN system 10 includes a plurality of high priority wireless LAN terminals 20, a wireless LAN terminal 40 other than a high priority wireless LAN terminal 40, and a plurality of access points 30. The communication area 61 indicates a range in which a radio wave having an assignable intensity is transmitted from the access point 30-1. The communication area 62 indicates a range in which a radio wave having an assignable intensity is transmitted from the access point 30-2. In FIG. 1, a dotted-line double arrow indicates that the wireless LAN terminal 20 or the wireless LAN terminal 40 is belonging, and a solid-line double arrow indicates that the wireless LAN terminal 20 or the wireless LAN terminal 40 is communicating. It is shown that.

  Each access point 30 is connected to the wired network 11, and performs wireless communication with each wireless LAN terminal 20 based on a wireless LAN standard such as IEEE802.11a or IEEE802.11b. Wired communication is performed with another communication device 12 connected to the wired network 11 via the communication standard such as Ethernet (registered trademark). In FIG. 1, the wired network 11 is applied as a network connecting a plurality of access points 30, but this may be a wireless network of a method different from the communication with the wireless LAN terminal 20 or the wireless LAN terminal 40. Good.

  Each wireless LAN terminal 20 or wireless LAN terminal 40 belongs to the access point 30 having the best received signal quality, for example. The received signal quality is, for example, received electric field strength, SNR (Signal to Noise Ratio), BER (Bit Error Rate) or the like. The wireless LAN terminal 20 or the wireless LAN terminal 40 performs wireless communication based on the wireless LAN with the access point 30 to which the wireless LAN terminal 20 or the wireless LAN terminal 40 belongs, and the other wireless LAN terminal belonging to the access point 30 through the access point 30. 20 or the wireless LAN terminal 40, another wireless LAN terminal 20 or the wireless LAN terminal 40 belonging to another access point 30, the communication device 12 connected to the wired network 11, and the like. In the present embodiment, each wireless LAN terminal 20 is a terminal that needs to maintain a high communication quality, for example, a voice communication terminal that mainly handles voice data. Furthermore, the wireless LAN terminal 40 is a data communication terminal that handles data that does not have to have high quality.

  By the way, when the number of wireless LAN terminals 20 or wireless LAN terminals 40 communicating via one access point 30 increases, the communication band allocated to each wireless LAN terminal 20 or wireless LAN terminal 40 may decrease. There are cases in which the transmission of voice and moving images that require real-time performance is hindered. In order to avoid this, the access point 30 in the present embodiment is configured to guarantee the communication band of each wireless LAN terminal 20 in cooperation with the wireless LAN terminal 20. As a method for guaranteeing the communication band, for example, there is HCCA (Hybrid coordination function Controlled Channel Access). At this time, the wireless LAN terminal 40 uses a communication band other than the communication band secured by the wireless LAN terminal 20.

  Here, “high communication quality” means a state where communication with a certain communication band or more is guaranteed, and “high communication quality” means a state where the communication band cannot be guaranteed. The communication load is the amount of data actually transmitted / received with respect to the amount of data that can be transmitted / received per unit time.

  In addition, each access point 30, such as the wireless LAN terminal 20-1 shown in FIG. 1, when newly assigning the wireless LAN terminal 20, other authentication or the like regardless of the current communication load. The attribution of the wireless LAN terminal 20 is permitted in consideration of the factors. In this case, the access point 30 stores in advance the maximum value of the number of wireless LAN terminals 20 to which the access point 30 can belong, and if it is less than the maximum value, the access point 30 considers other factors such as authentication and assigns the wireless LAN terminal 20 to the attribution. If it is permitted and the value exceeds the maximum value, the attribution of the new wireless LAN terminal 20 may not be permitted.

  In FIG. 1, the communication band necessary for enabling the wireless LAN terminal 20 to communicate while maintaining a high communication quality under the control of one access point 30 is the maximum number of wireless LAN terminals 20. It is assumed that there is a communication bandwidth for two devices, and of these, it is assumed that a communication bandwidth for one wireless LAN terminal 20 is allocated for communication of the wireless LAN terminal 40. At this time, when there are a plurality of wireless LAN terminals 40 belonging to the access point 30, the communication band for one wireless LAN terminal 20 is shared by the plurality of wireless LAN terminals 40 belonging to the access point 30. become.

  Here, as shown in FIG. 1, when the wireless LAN terminal 20-2 is communicating via the access point 30-1, the wireless LAN terminal 20-2 newly starts communication. 20-2 transmits a communication start request to the communication partner via the belonging access point 30-1. When the access point 30-1 detects this communication start request by monitoring, the access point 30-1 measures or calculates the communication load of the access point 30-1.

  However, in the example shown in FIG. 1, one wireless LAN terminal 20 and one wireless LAN terminal 40 are already communicating via the access point 30-1, and the communication of the access point 30-1 is performed. The load state is not a state in which the new wireless LAN terminal 20 can communicate. Therefore, the access point 30-1 transmits an AP information request for requesting information of another access point 30 to which the wireless LAN terminal 40-1 can belong, via the wired network 11 by multicast.

  The access point 30-2 searches for the wireless LAN terminal 20 or the wireless LAN terminal 40 existing in the vicinity in advance by periodic scanning or the like, and the wireless LAN terminal 40-1 can belong to the access point 30-2. Detected. The access point 30-2 responds to the AP information request received from the access point 30-1 by transmitting an AP information response via the wired network 11.

  The access point 30-1 receives AP information responses from the plurality of access points 30. The access point 30-1 determines the identification information of the access point 30 for changing the identification information (ID) from among the plurality of access points 30, and identifies the identification information of the plurality of access points 30. IDs of access points that do not match are also generated. Here, only the access point 30-2 has transmitted the AP information response, the identification information of the access point 30-1 is A, the identification information of the access point 30-2 is B, and the identification information of the access point 30-1 Assume that the identification information of the access point that does not match any of the identification information of the access point 30-2 is C.

  The access point 30-1 acquires B, which is identification information of the access point 30-2, from the AP information response received from the access point 30-2. C is generated as identification information of an access point that does not match B, which is identification information of No. 2.

  The access point 30-1 transmits an AP information change instruction including C as identification information of the access point to the subordinate wireless LAN terminal 20-2 and the wireless LAN terminal 20-3, and the access point 30-2 An AP information change instruction including A as the identification information is transmitted. When the access point 30-2 receives the AP information change instruction, the AP information including A as access point identification information is transmitted to the wireless LAN terminal 20-4 and the wireless LAN terminal 20-5 subordinate to the access point 30-2. Send change instructions. The access point identification information A is obtained from the AP information change instruction information received by the access point 30-2 from the access point 30-1.

  The wireless LAN terminal 20 and the access point 30 that have received the AP information change instruction match the timing based on the identification information change timing information instructed by the AP information change instruction, and hold it as access point identification information. Is changed to the specified identification information. Specifically, the access point 30-1 changes the identification information of its own access point to C, and the wireless LAN terminal 20-2 and the wireless LAN terminal 20-3 are held as belonging access points. The identification information is changed to C, the access point 30-2 changes its own access point identification information to A, and the wireless LAN terminal 20-4 and the wireless LAN terminal 20-5 subordinate to the access point 30-2 The identification information held as the belonging access point is changed to A.

  At this time, since the identification information of the access point to which the wireless LAN terminal 40-1 belongs is still A, the communication performed by the wireless LAN terminal 40-1 is performed via the access point 30-2. . As a result of changing the access point information in this way, the wireless LAN terminals belonging to the access point 30-1 are two, the wireless LAN terminal 20-2 and the wireless LAN terminal 20-3, and the access point 30- The wireless LAN terminals belonging to 2 are the wireless LAN terminal 20-4, the wireless LAN terminal 20-5, the wireless LAN terminal 40-1, and the wireless LAN terminal 40-3. At this time, the wireless LAN terminal that performs communication via the access point 30-1 is only the wireless LAN terminal 20-3, and the access band 30-1 can secure the communication band required by the wireless LAN terminal 20-2. The wireless LAN terminal 20-2 can start communication.

  As described above, when the wireless LAN terminal 20 with a high priority has no margin in the communication load of the access point 30 to which it belongs, another access is made from the access point 30 to which the wireless LAN terminal 20 with a high priority belongs. By moving the wireless LAN terminal 40 other than the wireless LAN terminal with high priority to the point 30, communication can be started without changing the access point 30 to which the wireless LAN terminal 20 belongs.

  In addition, when the communication of the wireless LAN terminal 20-2 or the wireless LAN terminal 20-3 is completed and only the belonging state is obtained, the access point 30-1 monitors the communication of the wireless LAN terminal 20, thereby The access point 30-1 detects that the communication of the LAN terminal 20 has ended, and the access point 30-1 sends an AP information change instruction including A as access point identification information to the wireless LAN terminal 20-2 subordinate to the access point 30-1. An AP information change instruction including B as access point identification information is transmitted to the access point 30-2. When the access point 30-2 receives the AP information change instruction, the access point 30-2 sends the AP information change instruction including B as access point identification information to the wireless LAN terminal 20-4 and the wireless LAN terminal 20 subordinate to the access point 30-2. Send to -5. The access point identification information B is obtained from the AP information change instruction information received by the access point 30-2 from the access point 30-1. The wireless LAN terminal 20 and the access point 30 that have received the AP information change instruction match the timing based on the identification information change timing information instructed by the AP information change instruction, and hold it as access point identification information. Information is changed to the acquired identification information. Specifically, the access point 30-1 changes the identification information of its own access point to A, and the wireless LAN terminal 20-2 and the wireless LAN terminal 20-3 are held as belonging access points. The identification information is changed to A, the access point 30-2 changes its own access point identification information to B, and the wireless LAN terminal 20-4 and the wireless LAN terminal 20-5 subordinate to the access point 30-2 The identification information held as the belonging access point is changed to B. In this way, when the access point identification information is changed to the identification information different from the originally held identification information and the communication of the wireless LAN terminal 20 is completed, the access point identification information information is stored in the original information. Process to return to.

  Hereinafter, functions of the wireless LAN terminal 20 and the access point 30 for realizing the above processing will be described in detail.

  FIG. 2 shows an example of a detailed functional configuration of the wireless LAN terminal 20. The wireless LAN terminal 20 includes an AP information changing unit 200 and a wireless communication unit 201.

  The wireless communication unit 201 performs attribution processing with the access point 30, and performs wireless communication based on the wireless LAN with the access point 30. For example, the wireless LAN terminal 20 performs attribution processing with the access point 30 having the best reception quality.

  When the AP information change unit 200 receives an AP information change instruction from the access point 30, the AP information change unit 200 changes information for communicating with the access point after performing a predetermined timing adjustment. The predetermined timing adjustment is performed, for example, by waiting until the time reaches a predetermined time. The information for communicating with the access point is changed by, for example, changing the memory stored as the identification information of the belonging access point to the identification information indicated by the AP information change instruction received from the access point 30. To do. The wireless communication unit 201 performs wireless communication with the access point 30 using the information changed by the AP information changing unit 200.

  FIG. 4 shows an example of a detailed functional configuration of the access point 30. The access point 30 includes an AP information changing unit 300, a wired communication unit 301, a terminal detection unit 302, a wireless communication unit 303, a communication band securing determination unit 304, a communication load detection unit 305, and a communication request detection unit 306.

  The wireless communication unit 303 performs wireless communication based on the wireless LAN with the wireless LAN terminal 20 or the wireless LAN terminal 40, sends communication data received from the wireless LAN terminal 20 or the wireless LAN terminal 40 to the wired communication unit 301, and performs wired communication. The communication data received from the unit 301 is sent to the wireless LAN terminal 20 or the wireless LAN terminal 40 by wireless communication. In addition, the wireless communication unit 303 performs wireless communication with the wireless LAN terminal 20 or the wireless LAN terminal 40 using the information changed by the AP information changing unit 300.

  The wireless communication unit 303 executes attribution processing with the wireless LAN terminal 20 or the wireless LAN terminal 40. The wireless communication unit 303 determines whether the assigned wireless LAN terminal is the wireless LAN terminal 20 or the wireless LAN terminal 40. For example, when the wireless communication unit 303 detects that the wireless LAN terminal belonging to the access point 30 is compatible with HCCA (Hybrid coordination function Control Access), the wireless LAN terminal If the wireless LAN terminal belonging to the access point 30 is not compatible with HCCA (Hybrid Coordination Channel Access), the wireless LAN terminal 40 is regarded as the wireless LAN terminal 20. It is considered. In addition, the identification information of the wireless LAN terminal 20 is registered in advance in the access point 30, and the wireless communication unit 303 previously registers the identification information of the wireless LAN terminal belonging to the access point 30. If it matches the identification information, the wireless LAN terminal may be regarded as the wireless LAN terminal 20, and if it does not match the previously registered identification information, the wireless LAN terminal may be regarded as the wireless LAN terminal 40.

  The wired communication unit 301 performs wired communication with other communication devices 12 and the like via the wired network 11 based on, for example, Ethernet (registered trademark).

  The communication request detection unit 306 monitors the communication data of the wireless LAN terminal 20 that is transmitted and received by the wireless communication unit 303, detects that the wireless LAN terminal 20 has transmitted or received a communication start request, and the wireless LAN terminal It is detected that 20 has ended the communication state. For example, when the call control procedure executed by the wireless LAN terminal 20 is SIP (Session Initiation Protocol), the communication start or end detection method is regarded as detection of a communication start request by detecting an INVITE request, such as BYE. By detecting the communication end message, it is considered that the state during communication has ended. When the communication request detection unit 306 detects that the wireless LAN terminal 20 has transmitted or received a communication start request, the communication request detection unit 306 instructs the communication band securing determination unit 304 to determine whether the communication band required by the wireless LAN terminal 20 A process of determining whether or not the access point 30 can be secured is started. When the communication request detection unit 306 detects that the wireless LAN terminal 20 has ended the communication state, the communication request detection unit 306 instructs the AP information changing unit 300 to set the AP information such as the access point identification information to the state before the change. Start the process to return.

  The communication load detection unit 305 measures or calculates the communication load generated at the access point 30 of the wireless LAN terminal 20 or the wireless LAN terminal 40 belonging to the access point 30. In this embodiment, the communication load detection unit 305 is used for communication by the wireless LAN terminal 20 or the wireless LAN terminal 40 belonging to or communicating with the access point 30 based on the information from the wireless communication unit 303. Managing the communication bandwidth. For example, the communication load detection unit 305 wirelessly stores information on the communication band of the wireless LAN terminal 20 or the wireless LAN terminal 40 that is held by the wireless communication unit 303 performing control of the HCCA (Hybrid Coordination Function Control Access). Obtained from the communication unit 303.

  The communication band securing determination unit 304 stores a predetermined communication load value, refers to the current communication load of the access point 30 measured or calculated by the communication load detection unit 305, and A communication band used by the wireless LAN terminal 40 belonging to the access point 30 when the communication load of the access point 30 cannot secure a communication band required by the new wireless LAN terminal 20 However, if the communication band is greater than that required by the wireless LAN terminal 20, the AP information changing unit 300 is instructed to start processing for acquiring access point information.

  The AP information changing unit 300 transmits an AP information request via the wired communication unit 301 when instructed by the communication band securing determination unit 304 to start processing for acquiring access point information. The AP information request includes, for example, information on the access point 30 and identification information on the wireless LAN terminal 40 belonging to the access point 30 as shown in the data 50 of FIG.

  The AP information request transmitted by the access point 30 is received by the AP information changing unit 300 of the other access point 30 via the wired communication unit 301 of the other access point 30. When the AP information change unit 300 receives the AP information request, the AP information change unit 300 detects the identification information of the wireless LAN terminal 40 included in the AP information request of the wireless LAN terminal 40 existing in the vicinity where the terminal detection unit 302 has already detected. If a search is made from the list of identification information and information that matches the identification information of the wireless LAN terminal 40 included in the AP information request is already held, an AP information response is transmitted via the wired communication unit 301. For example, as shown in the data 51 of FIG. 3, the AP information response is obtained by transmitting the information of the access point 30 that is transmitting the AP information response, the identification information of the wireless LAN terminal 40, and the AP information response. The reception quality of the wireless LAN terminal 40 detected by the existing access point 30 is included. The AP information response may be transmitted not only as a response to the AP information request but also at an arbitrary timing. The arbitrary timing may be, for example, when a change occurs in the list of identification information of the wireless LAN terminals 40 existing in the vicinity. By transmitting the AP information response in advance at an arbitrary timing, it is possible to omit the waiting state for receiving the AP information response.

  The AP information changing unit 300 of the access point 30 that has transmitted the AP information request receives the AP information response transmitted by a plurality of other access points 30 via the wired communication unit 301. The AP information changing unit 300 of the access point 30 that has transmitted the AP information request determines the identification information of the access point 30 for changing the identification information and receives the AP information response, and the plurality of access points 30 The identification information of the access point that does not match any identification information included in the received AP information response is generated. Hereinafter, for the sake of explanation, these pieces of identification information are identified from the identification information A of the access point 30, the identification information B of the access point 30 for changing the identification information, and the plurality of access points 30. The identification information of an access point that does not match any identification information included in the received AP information response is represented by identification information C and a symbol. As an example of a method for determining the identification information B, the AP information changing unit 300 compares the reception quality of the wireless LAN terminal 40 included in the AP information response received from the plurality of access points 30, and information with the best reception quality is obtained. The access point 30 that transmitted the AP information response with is selected.

  Subsequently, the AP information changing unit 300 of the access point 30 that transmitted the AP information request transmits an AP information change instruction to the wireless LAN terminal 20 under the access point 30 via the wireless communication unit 303. The AP information change instruction includes, for example, access point identification information and information on timing for changing the identification information, as shown in the data 52 of FIG. 3. At this time, the access point identification information is: Specify identification information C. Further, the AP information changing unit 300 of the access point 30 that has transmitted the AP information request transmits an AP information change instruction to the access point 30 having the identification information B via the wired communication unit 301. At this time, the identification information of the access point included in the AP information change instruction specifies identification information A.

  AP information change instructions transmitted from other access points 30 are received by the AP information change unit 300 via the wired communication unit 301. When the AP information change unit 300 receives the AP information change instruction, the AP information change unit 300 transmits the AP information change instruction to the wireless LAN terminal 20 under the access point 30 via the wireless communication unit 303. At this time, the identification information of the access point included in the AP information change instruction specifies the identification information of the received AP information change instruction.

  The access point 30 that has transmitted the AP information request changes its own identification information to the identification information C when it is time to change the identification information indicated by the AP information change instruction. The timing for changing the identification information is, for example, waiting until the time reaches a predetermined time. The access point 30 that has received the AP information change instruction indicates its own identification information in the AP information change instruction when it is time to change the identification information indicated in the received AP information change instruction. Change to identification information. When changing the identification information, the AP information changing unit 300 of the access point 30 may change information other than the identification information based on information other than the identification information included in the AP information change instruction. In addition, when the identification information is changed, the AP information changing unit 300 of the access point 30 newly updates the wireless LAN terminal 40 under the access point 30 in order to update the routing information of devices other than the access point 30. A broadcast packet having the identification information as a transmission source address may be transmitted via the wired communication unit 301 and the wireless communication unit 303.

  The AP information changing unit 300 of the access point 30 that has transmitted the AP information request holds the identification information A, the identification information B, and the identification information C, and the AP information such as the access point identification information from the communication request detection unit 306. Is instructed to start the process of returning to the state before the change, the AP information change instruction including the identification information A is sent to the wireless LAN terminal 20 under the access point 30 via the wireless communication unit 303. The AP information change instruction including the identification information B is transmitted to the access point 30 originally having the identification information B via the wired communication unit 301, and is indicated by the transmitted AP information change instruction. When it is time to change the identification information, its own identification information is returned to the identification information A.

  The terminal detection unit 302 detects the identification information and reception quality of the wireless LAN terminal 40 existing in the vicinity via the wireless communication unit 303, and holds the detected information as a list. As an example of a method for detecting the wireless LAN terminal 40 existing in the vicinity, the terminal detection unit 302 performs a channel scan via the wireless communication unit 303 at a predetermined timing, and the wireless LAN terminal 40 existing in the vicinity Identification information and reception quality are detected. The list of identification information of the wireless LAN terminal 40 existing in the vicinity includes, for example, as shown in the data 53 of FIG. 3, the identification information of the wireless LAN terminal, the reception quality of the wireless LAN terminal from the access point, and the wireless Information on the channel on which the LAN terminal is detected is included.

  FIG. 5 is a flowchart showing an example of the operation of the wireless LAN terminal 20. For example, at a predetermined timing such as when the power is turned on, the wireless LAN terminal 20 starts the processing shown in this flowchart.

  First, the AP information change unit 200 determines whether an AP information change instruction has been received via the wireless communication unit 201 (S100). When the AP information change instruction has not been received (S100: No), the AP information change unit 200 repeats Step 100.

  When the AP information change instruction is received (S100: Yes), it is determined whether or not the timing instructed by the AP information change instruction has come (S101). When it is not the timing instructed by the AP information change instruction (S101: No), the AP information change unit 200 repeats Step 101.

  When the timing instructed by the AP information change instruction is reached (S101: Yes), the AP information changing unit 200 changes the information recognized as the access point identification information to the identification information instructed by the AP information change instruction. The process shown in step 100 is performed again.

  FIG. 6 is a flowchart showing an example of the operation of the access point 30. For example, at a predetermined timing such as when the power is turned on, the access point 30 executes the processing shown in this flowchart.

  First, the communication request detection unit 306 determines whether or not a request to start communication of the wireless LAN terminal 20 has been detected (S200). When the communication start request is detected (S200: Yes), the communication band securing determination unit 304 determines whether or not the communication band can be secured (S201). As a result of determining whether or not the communication band can be secured, the communication band securing determination unit 304 determines whether or not to make an AP information request (S202). The communication band securing determination unit 304 is a case where the communication band required by the new wireless LAN terminal 20 cannot be secured, and the communication band used by the wireless LAN terminal 40 belonging to the access point 30 is If it is determined that the communication band required by the new wireless LAN terminal 20 cannot be secured and it is not necessary to make an AP information request, such as when the communication band is less than the communication band used by the wireless LAN terminal 20 (S202: No), the process shown in step 200 is performed again.

  If it is determined that an AP information request needs to be made (S202: Yes), the AP information changing unit 300 transmits an AP information request to another access point 30 (S203). The AP information changing unit 300 determines whether an AP information response has been received from another access point 30 (S204). When the AP information changing unit 300 has not received an AP information response (S204: No), the AP information changing unit 300 repeats the process shown in step 204 until a certain period of time elapses.

  When the AP information change unit 300 receives an AP information response or when a certain period of time has elapsed (S204: Yes), the AP information change unit 300 determines whether valid information is obtained in the received AP information response (S205). When there is no valid information in the received AP information response, or when the AP information response is not received and a certain period of time has elapsed (S205: No), the processing shown in step 200 is performed again.

  When there is valid information in the received AP information response (S205: Yes), the AP information changing unit 300 determines the identification information of the access point 30 for changing the identification information (S206). Hereinafter, this identification information is referred to as identification information B. Further, the AP information changing unit 300 generates identification information of an access point that does not match any identification information included in the AP information response received from the plurality of access points 30 (S206). Hereinafter, this identification information is referred to as identification information C. Hereinafter, the identification information of the access point 30 is referred to as identification information A. Then, the AP information changing unit 300 transmits an AP information change instruction including the identification information A to the access point 30 to be subjected to the change of the identification information (S207), and an AP information change instruction including the identification information C is It transmits to the wireless LAN terminal 20 under the access point 30 (S208). Thereafter, the AP information changing unit 300 determines whether or not the timing indicated by the transmitted AP information change instruction has come (S209). If the instructed timing has not come (S209: No), the processing shown in step 209 is repeated. When the instructed timing is reached (S209: Yes), the AP information is changed to the information of the identification information C (S210), and the process shown in step 200 is performed again.

  When the communication request is not detected in the process shown in step 200 (S200: No), the communication request detection unit 306 determines whether the end of communication is detected (S216). When the end of communication is detected (S216: Yes), an AP information change instruction including the identification information B is transmitted to the other access point 30 that has changed the identification information (S207), and the AP including the identification information A is transmitted. An information change instruction is transmitted to the wireless LAN terminal 20 under the access point 30 (S208). Thereafter, the AP information changing unit 300 determines whether or not the timing indicated by the transmitted AP information change instruction has come (S209). If the instructed timing has not come (S209: No), the processing shown in step 209 is repeated. When the instructed timing is reached (S209: Yes), the AP information is changed to the information of the identification information A (S210), and the process shown in step 200 is performed again.

  If the end of communication is not detected in the process shown in step 216 (S216: No), the AP information change unit 300 determines whether an AP information change instruction has been received from another access point 30 (S217). When the AP information change instruction is received (S217: Yes), the AP information change unit 300 transmits the received AP information change instruction to the wireless LAN terminal 20 under the access point 30 (S208). Thereafter, the AP information changing unit 300 determines whether or not the timing instructed by the received AP information change instruction has come (S209). If the instructed timing has not come (S209: No), the processing shown in step 209 is repeated. When the instructed timing is reached (S209: Yes), the AP information changing unit 300 changes the AP information with the information of the identification information instructed by the received AP information change instruction (S210), and the process is shown in Step 200 again. Process.

  When the AP information change instruction is not received in the process shown in step 217 (S217: No), the AP information change unit 300 determines whether an AP information request is received from another access point 30 (S211). When the AP information request is received (S211: Yes), the identification information of the wireless LAN terminal 40 indicated by the received AP information request is searched from the list held by the terminal detection unit 302 (S212). If there is information as a result of the search (S213: Yes), the AP information changing unit 300 transmits an AP information response to the access point 30 that has transmitted the AP information request (S214), and again shown in step 200. Process. In the process shown in step 213, when there is no information as a result of the search (S213: No), the process shown in step 200 is performed again.

  When the AP information request is not received in the process shown in step 211 (S211: No), the terminal detection unit 302 determines whether or not it is the channel scan timing (S218). When it is time for channel scanning (S218: Yes), the terminal detection unit 302 performs channel scanning (S219). If the wireless LAN terminal 20 or the wireless LAN terminal 40 is detected as a result of performing the channel scan, the terminal detection unit 302 holds the information of the detected wireless LAN terminal in a list (S220), and the process shown in step 200 again. I do.

  If it is not the channel scan timing in the process shown in step 218 (S218: No), the process shown in step 200 is performed again.

  FIG. 7 is a sequence diagram showing an example of the operation of the wireless LAN system 10. In the sequence shown in FIG. 7, the wireless LAN terminal 20-1 at a position where it can receive radio waves with sufficient strength to belong from a plurality of access points 30 has an access point 30-1 with no margin in the current communication load. When the communication is started, the wireless LAN terminal 40 belonging to the access point 30-1 is attributed to the other access point 30-2, and the wireless LAN terminal 20-1 ends the communication. In this example, the wireless LAN terminal 40 belonging to the access point 30-2 is attributed to the original access point 30-1.

  First, it is assumed that the wireless LAN terminal 40 is communicating under the access point 30-1 (S301), the wireless LAN terminal 20-1 is belonging under the access point 30-1 (S303), and the wireless LAN terminal It is assumed that 20-2 is communicating under the access point 30-2 (S302). In addition, for the following explanation, the identification information of the access point 30-1 is the identification information A, the identification information of the access point 30-2 is the identification information B, and both the identification information A and the identification information B are different. The identification information is defined as identification information C.

  It is assumed that the terminal detection unit 302 of the access point 30-2 performs the channel scan and detects the wireless LAN terminal 40 when the channel scan timing comes (S304). The terminal detection unit 302 of the access point 30-2 holds information on the detected wireless LAN terminal 40 (S305).

  In order to communicate with the communication device 12, the wireless LAN terminal 20-1 transmits a communication start request via the access point 30-1 (S306, S307). The communication request detection unit 306 of the access point 30-1 detects the communication start request transmitted by the wireless LAN terminal 20-1 (S308). Then, the communication band securing determination unit 304 of the access point 30-1 determines whether the communication band required by the wireless LAN terminal 20 can be secured from the current communication load of the access point 30-1 (S309). The communication band securing determination unit 304 of the access point 30-1 has no margin in the current communication load of the access point 30-1, and there is a wireless LAN terminal 40 in communication under the access point 30-1. Therefore, it is determined to transmit the AP information request.

  In response to the result of the determination in step 309, the AP information changing unit 300 of the access point 30-1 transmits an AP information request including information on the wireless LAN terminal 40 to the other access point 30 (S310). The AP information changing unit 300 of the access point 30-2 receives the AP information request from the access point 30-1, and uses the wireless LAN terminal 40 information included in the AP information request as the terminal of the access point 30-2. A search is performed from information on the wireless LAN terminal held by the detection unit 302. As a result of the search, since it is detected that the information of the wireless LAN terminal 40 is held, the AP information changing unit 300 of the access point 30-2 transmits an AP information response to the access point 30-1 (S311). .

  The AP information changing unit 300 of the access point 30-1 generates identification information C from the identification information of the access point 30-2 indicated by the AP information response received from the access point 30-2 (S312). An AP information change instruction including identification information C as information is transmitted to the wireless LAN terminal 20-1 subordinate to the access point 30-1 (S313), and an AP information change instruction including identification information A as identification information information is transmitted. The data is transmitted to the access point 30-2 (S314).

  The AP information changing unit 300 of the access point 30-2 transmits the AP information change instruction information received from the access point 30-1 to the wireless LAN terminal 20-2 subordinate to the access point 30-2 (S315). AP information change unit 200 of wireless LAN terminal 20-1, AP information change unit 300 of access point 30-1, AP information change unit 300 of access point 30-2, and AP information change of wireless LAN terminal 20-2 The unit 200 waits until the timing indicated by the AP information change instruction transmitted / received in Step 313, Step 314, or Step 315 is reached. When the timing instructed by the AP information change instruction comes, the AP information changing unit 200 of the wireless LAN terminal 20-1 changes the identification information held as the belonging access point to the identification information C. (S316), the AP information changing unit 300 of the access point 30-1 changes the identification information of the own access point to the identification information C (S317), and the AP information changing unit 300 of the access point 30-2 Is changed to identification information A (S318), and the AP information changing unit 200 of the wireless LAN terminal 20-2 changes the identification information held as the belonging access point to identification information A (S319). .

  At this time, since the identification information of the access point 30-2 is A, the data transmitted and received by the wireless LAN terminal 40 that is recognized as belonging to the access point 30 of the identification information A is the access point 30-2. (S320). In addition, since the identification information to be recognized by both the wireless LAN terminal 20-1 and the access point 30-1 is the identification information C, data transmitted and received by the wireless LAN terminal 20-1 is transmitted via the access point 30-1. (S321, S322).

  When the wireless LAN terminal 20-1 ends communication (S323, S324), the communication request detection unit 306 of the access point 30-1 detects the end of communication of the wireless LAN terminal 20-1 (S325). The AP information changing unit 300 of the access point 30-1 that detected the end of communication sends an AP information change instruction including the identification information A as identification information information to the wireless LAN terminal 20-1 subordinate to the access point 30-1. It transmits (S326), and transmits an AP information change instruction including identification information B as identification information information to the access point 30-2 (S327).

  The AP information changing unit 300 of the access point 30-2 transmits the AP information change instruction information received from the access point 30-1 to the wireless LAN terminal 20-2 subordinate to the access point 30-2 (S328). AP information change unit 200 of wireless LAN terminal 20-1, AP information change unit 300 of access point 30-1, AP information change unit 300 of access point 30-2, and AP information change of wireless LAN terminal 20-2 The unit 200 waits until the timing indicated by the AP information change instruction transmitted / received in Step 326, Step 327, or Step 328 is reached. When the timing indicated by the AP information change instruction is reached, the AP information change unit 200 of the wireless LAN terminal 20-1 changes the identification information held as the belonging access point to the identification information A. (S329), the AP information changing unit 300 of the access point 30-1 changes the identification information of the own access point to the identification information A (S330), and the AP information changing unit 300 of the access point 30-2 is changed to the own access point. Is changed to identification information B (S331), and the AP information changing unit 200 of the wireless LAN terminal 20-2 changes the identification information held as the belonging access point to identification information B (S332). .

  At this time, since the identification information of the access point 30-1 is A, the data transmitted and received by the wireless LAN terminal 40 that is recognized as belonging to the access point 30 of the identification information A is the access point 30-1. (S333).

  The embodiment of the present invention has been described above.

  As is apparent from the above description, according to the wireless LAN system 10 of the present invention, the communication quality of the wireless LAN terminal 20 can be kept high, and the wireless LAN that needs to keep the communication quality high like a telephone terminal is required. More terminals 20 can be attributed to the access points 30 with good reception signal quality.

  In addition, this invention is not limited to said embodiment, Many deformation | transformation are possible within the range of the summary.

1 is a system configuration diagram showing an example of a configuration of a wireless LAN system 10 according to an embodiment of the present invention. 2 is a block diagram illustrating an example of a detailed functional configuration of a wireless LAN terminal 20. FIG. 2 is an explanatory diagram illustrating an example of a configuration of data transmitted / received in a wireless LAN system 10 and an example of data held in an access point 30. FIG. 3 is a block diagram illustrating an example of a detailed functional configuration of an access point 30. FIG. 4 is a flowchart showing an example of the operation of the wireless LAN terminal 20. 3 is a flowchart showing an example of the operation of an access point 30. 4 is a sequence diagram illustrating an example of an operation of the wireless LAN system 10. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wireless LAN system, 11 ... Wired network, 12 ... Communication apparatus, 61, 62 ... Communication area, 20 ... Wireless LAN terminal, 200 ... AP information change part, 201. ..Wireless communication unit, 30 ... access point, 300 ... AP information changing unit, 301 ... wired communication unit, 302 ... terminal detection unit, 303 ... wireless communication unit, 304 ... Communication band securing determination unit, 305 ... Communication load detection unit, 306 ... Communication request detection unit, 40 ... Wireless LAN terminal, 50, 51, 52, 53 ... Data

Claims (4)

A wireless LAN system comprising a plurality of access points (sometimes abbreviated as AP) and a plurality of wireless LAN terminals,
Each of the plurality of wireless LAN terminals is
The terminal side AP information changing means for acquiring the identification information of the access point via the access point being belonging, and rewriting the identification information held as the access point being belonging to the obtained identification information,
Each of the plurality of access points is
Communication start request detecting means for detecting a communication start request of a wireless LAN terminal belonging to the own access point;
Communication end detection means for detecting the communication end of the wireless LAN terminal belonging to the own access point;
A communication load detecting means for measuring or calculating a communication load generated in the own access point;
When the communication start request detecting means detects a communication start request of the wireless LAN terminal belonging to its own access point, the communication required by the wireless LAN terminal from the communication load detected by the communication load detecting means A communication bandwidth securing judging means for judging whether or not the bandwidth can be secured;
Terminal detecting means for detecting the wireless LAN terminal existing in the vicinity of the own access point;
Acquire access point identification information from another access point, rewrite the own access point identification information to the acquired identification information, and identify the access point to the wireless LAN terminal or other access point belonging to the own access point. A wireless LAN system, comprising: AP-side AP information changing means for transmitting information. The wireless LAN system according to claim 1,
When the wireless LAN terminal that has made the communication start request is a wireless LAN terminal with high priority,
The communication band securing determination means includes
Of the communication loads detected by the communication load detection means, when the communication load by a terminal other than the high-priority wireless LAN terminal belonging to the own access point is a predetermined value or more, the communication start request is issued. A wireless LAN system that determines that a communication band required by a wireless LAN terminal having a high priority can be secured. The wireless LAN system according to claim 2,
The AP side AP information changing means includes:
An AP information request belonging to the own access point and including identification information of a terminal other than the high priority wireless LAN terminal is transmitted to the other access point,
The other access point is
When there is information on terminals other than the high priority wireless LAN terminal indicated in the AP information request in the information on the wireless LAN terminal acquired by the terminal detection means implemented by the other access point,
Or, when there is a change in the information of the wireless LAN terminal acquired by the terminal detection means,
An AP information response including identification information of the own access point is transmitted to the access point that transmitted the AP information request,
The access point that has transmitted the AP information request determines access point identification information for changing the identification information from the plurality of access point identification information included in the received plurality of AP information responses; Generate access point identification information that does not match any of the multiple access point identification information,
The access point that has transmitted the AP information request transmits an AP information change instruction including identification information of the own access point to the access point that has transmitted the AP response.
The access point that transmitted the AP response changes the identification information of the own access point to the identification information included in the AP information change instruction received from the access point that transmitted the AP information request, and the AP information Transmitting the AP information change instruction including the identification information included in the AP information change instruction received from the access point that transmitted the request to the wireless LAN terminal under its own access point;
The access point that has transmitted the AP information request uses the access point identification information included in the received AP information response as the access point identification information that does not match any of the plurality of access point identification information. The AP information change instruction including the identification information of the access point that does not match any of the plurality of identification information of the access point included in the received AP information response is subordinate to the own access point. To the wireless LAN terminal
When the communication end detection unit detects the communication end of the wireless LAN terminal in communication,
The access point that transmitted the AP information request changes the identification information of the own access point to the original identification information of the own access point, and the AP information change instruction including the identification information of the original access point To the wireless LAN terminal under its access point,
The access point that transmitted the AP information request transmits the AP information change instruction including the identification information originally possessed by the access point that transmitted the AP response to the access point that transmitted the AP response.
The access point that transmitted the AP response changes the identification information of the own access point to the identification information included in the received AP information change instruction, and includes the identification information included in the received AP information change instruction. A wireless LAN system, wherein the AP information change instruction is transmitted to a wireless LAN terminal under its own access point. An access point that is used in a wireless LAN system and performs wireless communication with a wireless LAN terminal,
Communication start request detecting means for detecting a communication start request of a wireless LAN terminal belonging to the own access point;
Communication end detection means for detecting the communication end of the wireless LAN terminal belonging to the own access point;
A communication load detecting means for measuring or calculating a communication load generated in the own access point;
When the communication start request detecting means detects a communication start request of the wireless LAN terminal belonging to its own access point, the communication required by the wireless LAN terminal from the communication load detected by the communication load detecting means A communication bandwidth securing judging means for judging whether or not the bandwidth can be secured;
Terminal detecting means for detecting the wireless LAN terminal existing in the vicinity of the own access point;
Acquire access point identification information from another access point, rewrite the own access point identification information to the acquired identification information, and identify the access point to the wireless LAN terminal or other access point belonging to the own access point. An access point comprising AP-side AP information changing means for transmitting information.

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