JP6398817B2 - Wireless LAN communication system and wireless LAN communication device - Google Patents

Description

  The present invention relates to a wireless LAN communication system and a wireless LAN communication device.

  In recent years, a plurality of wireless LAN communication devices have been used in organizations such as companies. Wireless LAN communication devices include a parent device (device having an access point function) and a slave device (device having a client function such as a PC or a smartphone), as well as a relay device (device having an access point function and a client function). For example, a device that relays wireless LAN communication with a device equipped with a wireless communication device). In other words, in such networks, wireless LAN communication devices are premised on the types of devices that do not move frequently, such as parent devices and relay devices, and types that move places like child devices. There are mixed types of devices with different communication speed fluctuation factors.

JP 2009-105785 A

  However, in the conventional technology, for example, the base unit and the repeater set the communication link rate for any communication partner of a plurality of communication partners having different requirements for wireless communication stability (different types). And changes were made in the same way, and communication was not sufficiently stabilized.

  Note that Patent Document 1 discloses an example in which a period for determination regarding rate switching is performed within a reference time in order to realize stable wireless communication (FIG. 4).

  The present invention has been made in view of the above circumstances, and provides a wireless LAN communication system and a wireless LAN communication apparatus capable of stabilizing communication in an environment where various wireless LAN communication apparatuses are mixed. One of its purposes is to do.

  A wireless communication system according to the present invention that solves the problems of the conventional example includes a plurality of wireless LAN communication devices, each of which has at least one of an access point function unit and a client function unit. And a wireless LAN communication system connected to be communicable with each other, wherein the wireless LAN communication apparatus having the access point function unit determines a type of a first wireless LAN communication apparatus that is a communication partner. And a link for wireless communication with the first wireless LAN communication device according to different determination criteria depending on whether the first wireless LAN communication device is determined to be a type of a device to be controlled by the determining device. Determining means for determining whether or not to control the rate; and when the determining means determines that the link rate should be controlled, It is obtained by the fact that a control means for controlling the Nkureto.

  By performing link rate control in accordance with the type of communication partner in this way, it is possible to stabilize wireless communication in an environment where various wireless LAN communication devices are mixed.

  One embodiment of the present invention is a wireless LAN communication device that includes an access point function unit and is connected to be communicable with a first wireless LAN communication device that is another wireless LAN communication device. A LAN communication device that determines a type of the first wireless LAN communication device; and whether the determination unit determines that the first wireless LAN communication device is a type of a device to be controlled. The determination means for determining whether or not to control the link rate of the wireless communication with the first wireless LAN communication device, and the determination means determined to control the link rate based on different determination criteria And a control means for controlling the link rate.

  Accordingly, by performing link rate control according to the type of communication partner, it is possible to stabilize wireless communication in an environment where various wireless LAN communication devices are mixed.

  Here, the determination criterion is a determination for determining whether or not to control the link rate of the wireless communication based on whether or not the rate of occurrence of communication errors with the first wireless LAN communication device is equal to or less than a predetermined rate. The predetermined ratio in the determination criterion when the determination unit determines that the first wireless LAN communication device is the control target device is a reference, and the first wireless LAN communication device is the control target. You may make it lower than the said predetermined ratio when it determines with it not being an apparatus.

  Further, the determination criterion is whether or not the number of times that communication errors with the first wireless LAN communication device are not continuously generated is equal to or greater than a predetermined number, and the first wireless LAN communication device is determined by the determination unit. The predetermined number of times in the determination criterion when it is determined that the device is the control target device is greater than the predetermined number of times when the first wireless LAN communication device is determined not to be the control target device. Also good.

  In this way, the criteria for determining whether or not to control the link rate will change depending on the type of communication partner, and in a mixed environment of various wireless LAN communication devices, stabilization of wireless communication is possible. It becomes possible to plan.

  Furthermore, another aspect of the present invention includes an access point function unit, and is connected to be communicable with a first wireless LAN communication device that is another wireless LAN communication device. A wireless LAN communication device that is different from a communication device and is communicably connected to a second wireless LAN communication device having an access point function unit, wherein the first wireless LAN communication The first wireless LAN communication according to different determination criteria depending on whether or not the first wireless LAN communication device is determined to be the type of the device to be controlled by the determining means for determining the type of device. Determining means for determining whether or not to control a link rate for wireless communication with a device; and when the determining means determines to control the link rate, the link rate is determined. And control means for controlling, in which it was decided and a relay means for relaying communication between the first wireless LAN communication device and the second wireless LAN communication device.

  By performing link rate control in accordance with the type of communication partner in this way, it is possible to stabilize wireless communication in an environment where various wireless LAN communication devices are mixed.

  According to the present invention, it is possible to perform link rate control in accordance with the type of communication partner, and it is possible to stabilize wireless communication in an environment where various wireless LAN communication devices coexist. It becomes possible.

1 is a configuration block diagram illustrating an example of a wireless LAN communication system according to an embodiment of the present invention. It is a functional block diagram showing the example of the wireless LAN communication apparatus which concerns on embodiment of this invention. It is explanatory drawing showing the structural example of the wireless LAN communication system which concerns on embodiment of this invention. It is explanatory drawing showing the operation example of the wireless LAN communication apparatus which concerns on embodiment of this invention. It is a functional block diagram showing another example of the wireless LAN communication apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. As illustrated in FIG. 1, the wireless LAN communication system according to the embodiment of the present invention includes a parent device 10 as a wireless LAN communication device, a relay device 20, and a child device 30. Here, there may be a plurality of repeaters 20 and slave units 30. The base unit 10 and the relay unit 20 are generally fixedly placed at a predetermined place in the building, whereas the handset 30 is a notebook PC, a smartphone, or the like, and is carried by the user and moved. Is.

  Here, base unit 10 has an access point function unit, and handset unit 30 has a client function unit. The repeater 20 includes an access point function unit. The repeater 20 may also include a client function unit, and communication with the parent device 10 may be performed by the client function unit. The relay device 20 may communicate with the parent device 10 by using a WDS (Wireless Distribution System) function.

  As illustrated in FIG. 1, the base unit 10 includes a control unit 11, a storage unit 12, a wired communication unit 13, and a wireless communication unit 14. The repeater 20 includes a control unit 21, a storage unit 22, and a wireless communication unit 23.

  Here, the control unit 11 of the base unit 10 is a program control device such as a CPU, and operates according to a program stored in the storage unit 12. In the present embodiment, the control unit 11 has an access point function unit, and operates as a wireless LAN access point. The control unit 11 includes information for identifying each of other wireless LAN communication devices connected as wireless communication partners via the wireless communication unit 14 (its MAC address may be used), a corresponding wireless LAN communication device, Link rate table information associated with link rate (modulation scheme, coding rate, etc.) information used for the communication is stored in the storage unit 12. Specifically, link rate information used for communication is generated at the time of connection with a wireless LAN communication apparatus that is a communication partner, and is included in this link rate table information and stored in the storage unit 12.

  In addition, the control unit 11 according to the present embodiment determines the type of each of the other wireless LAN communication devices that are counterparts of wireless communication. Specifically, this type is a type indicating whether or not the device has a predetermined control function and is a target of a predetermined control (a type of whether or not another wireless LAN communication device is a control target device). is there.

  As a result of the determination, the control unit 11 determines whether the link rate should be controlled based on a predetermined determination criterion, such as whether the link rate can be increased, when the wireless communication partner is the type of the control target device. When it is determined that the link rate should be controlled, a process for controlling the link rate is executed. Further, as a result of the determination, when the wireless communication partner is the type of the device to be controlled, the control unit 11 uses a predetermined method to connect with the other wireless LAN communication device that is the wireless communication partner. An upper limit value of the link rate may be set. In this case, the control unit 11 controls the wireless communication unit 14 to perform wireless communication with the corresponding communication partner at a link rate equal to or lower than the upper limit set for the wireless communication partner.

  In the present embodiment, there may be a plurality of types of control target devices such as a first type control target device, a second type control target device, and so on. In this case, the control unit 11 determines not only whether or not it is a device to be controlled as a type of another wireless LAN communication device that is a partner of wireless communication via the wireless communication unit 14, but also what type of control target device. The number of times Ni determined for each type (i = 1, 2,..., Where Ni is an integer of 2 or more) is determined as a different criterion for each type of wireless communication partner. The success or failure of the wireless communication is determined repeatedly. And the control part 11 performs the process which controls a link rate according to the result of this judgment. Further, the control unit 11 may set the upper limit value of the link rate by a different method for each type of the determined counterpart of wireless communication. The operation of these control units 11 will be described in detail later.

  The storage unit 12 is a memory device or the like and holds a program executed by the control unit 11. This program may be provided by a computer-readable and non-transitory recording medium such as a DVD-ROM and copied to the storage unit 12 or via a communication line such as a network. Provided and copied to the storage unit 12. The storage unit 12 also operates as a work memory for the control unit 11.

  The wired communication unit 13 is a wired LAN interface, is connected to the wired LAN, receives information via the wired LAN, and outputs the received information to the control unit 11. The wired communication unit 13 sends out the instructed information via the wired LAN in accordance with the instruction input from the control unit 11.

  The wireless communication unit 14 is a wireless LAN interface, performs wireless communication with another wireless LAN communication device, and outputs information received from the other wireless LAN communication device to the control unit 11. The wireless communication unit 14 sends the instructed information to another wireless LAN communication device at the instructed link rate in accordance with the instruction input from the control unit 11.

  The control unit 21 of the relay machine 20 is a program control device such as a CPU, and operates according to a program stored in the storage unit 22. In the present embodiment, the control unit 21 operates as a wireless LAN relay device, and is a first wireless LAN communication device (for example, the slave device 30 or another relay device 20) that is another wireless LAN communication device. A second wireless LAN communication device (for example, the base unit 10) that is connected to the first wireless LAN communication device and is different from the first wireless LAN communication device and has an access point function unit. Are communicably connected to each other and relay communication between the first wireless LAN communication device and the second wireless LAN communication device.

  Further, in the present embodiment, the control unit 21 specifies information for identifying each of the other wireless LAN communication devices connected as wireless communication partners via the wireless communication unit 23 (as in the example of the base unit 10). The link rate table information that associates the MAC address) with the link rate (modulation method, coding rate, etc.) information used for communication with the corresponding wireless LAN communication device is stored in the storage unit 22. Also in this repeater 20, link rate information used for communication is generated at the time of connection with the wireless LAN communication apparatus that is the other party of communication, and is included in this link rate table information and stored in the storage unit 22.

  In addition, the control unit 21 according to the present embodiment determines the type of each of the other wireless LAN communication apparatuses that are wireless communication partners. This type is also a type indicating whether or not the device has a predetermined control function and is a target of predetermined control (a type of whether or not another wireless LAN communication device is a control target device). .

  As a result of the determination, the control unit 21 determines whether the link rate should be controlled based on a predetermined determination criterion, such as whether the link rate can be increased, when the wireless communication partner is the type of the device to be controlled. When it is determined that the link rate should be controlled, a process for controlling the link rate is executed. Further, as a result of the determination, when the wireless communication partner is the type of the device to be controlled, the control unit 21 uses a predetermined method to communicate with another wireless LAN communication device that is the wireless communication partner. An upper limit value of the link rate may be set. In this case, the control unit 21 controls the wireless communication unit 23 to perform communication with the corresponding wireless communication partner at a link rate equal to or lower than the upper limit set for the wireless communication partner.

  Also in this case, there may be a plurality of types of control target devices, such as a first type control target device, a second type control target device, and so on. In this case, the control unit 21 not only determines whether the other wireless LAN communication device that is a partner of wireless communication via the wireless communication unit 23 is a control target device, but also what type of control target. The number of times Ni (i = 1, 2,...; Ni is an integer equal to or greater than 2) determined for each type as a determination criterion that is different for each type of the determined wireless communication partner. ) Repeatedly to determine the success or failure of the wireless communication. Then, the control unit 21 determines whether or not the link rate should be controlled, such as whether or not the link rate can be increased, and controls the link rate when it is determined that the link rate should be controlled. Execute the process. Further, the control unit 11 may set the upper limit value of the link rate by a different method for each type of the determined counterpart of wireless communication. The operation of these control units 21 will be described in detail later.

  The storage unit 22 is a memory device or the like, and holds a program executed by the control unit 21. This program may be provided by a computer-readable and non-transitory recording medium such as a DVD-ROM and copied to the storage unit 22 or via a communication line such as a network. May be provided and copied to the storage unit 22. The storage unit 22 also operates as a work memory for the control unit 21.

  The wireless communication unit 23 is a wireless LAN interface, and performs wireless communication with the parent device 10 and the child device 30, which are other wireless LAN communication devices, and also with other relay devices 20, and the other Information received from the wireless LAN communication device is output to the control unit 21. The wireless communication unit 23 transmits the instructed information to another wireless LAN communication device at the instructed link rate in accordance with the instruction input from the control unit 21.

  In an example of the present embodiment, the control unit 11 of the parent device 10 and the control unit 21 of the relay device 20 operate according to programs stored in the storage unit 12 or the storage unit 22, respectively, as illustrated in FIG. The function as the access point function unit 40 is realized. The access point function unit 40 operates as an access point function. In this embodiment, the access point function unit 40 further includes a communication destination type determination unit 41, an upper limit setting unit 42, a communication success / failure determination unit 43, and a link rate control unit. 44 functionally.

  The communication destination type determination unit 41 determines the type of each communication partner that is performing direct communication via the wireless communication unit 14 or the wireless communication unit 23. Here, as already exemplified, the type may be different whether or not the device is a control target device having a predetermined control function, or may be different such as the presence or absence of an access point function unit or a client function unit. Good. Also, whether it is a device with limited relative position fluctuation (installed at a fixed position or moved together) or a device whose relative position varies relatively greatly Good. Specifically, the communication destination type determination unit 41 determines the type of communication partner by the following method.

  That is, in an example of the present embodiment, the control unit 21 of the repeater 20 includes the IEEE 802 in communication data transmitted via the wireless communication unit 23 (for example, a probe request, an authentication request, an association request, etc.). .11 in the Vender IE (Information Element) defined in the wireless LAN management frame defined in the standard of 11) that the device is a control target device having a specific control function (or as a predetermined control) Information indicating that it is a target of a predetermined link rate control, hereinafter referred to as a device to be controlled).

  Then, the communication destination type determination unit 41 determines the type of communication destination for each communication partner by checking whether the communication data transmitted by the communication partner includes information indicating that the device is a control target device. To do.

  Specifically, an example will be described in which information indicating that the relay device 20 is a control target device is included in the association request. In this example, the communication destination type determination unit 41 checks whether or not information indicating that the device is a control target device is included in the association request for each communication partner that has received the association request. If the association request includes information indicating that the device is a control target device, when the connection with the communication partner is performed, the communication partner is the control target device with respect to the information specifying the communication partner. Is stored in the storage unit 12 or the storage unit 22 as a type database.

  The communication destination type determination unit 41 does not add information to the type database unless the association request sent by the communication partner includes information indicating that the device is a control target device.

  Furthermore, in another example of the present embodiment, the communication destination type determination unit 41 may determine the type of communication partner based on a time change in throughput with each communication partner. In this example, it is not necessary for the relay device 20 to include information indicating that the relay device 20 is a control target device in the communication data to be transmitted.

  The communication destination type determination unit 41 according to this example examines a change in throughput over a predetermined time for each communication partner (for example, stores the minimum value and the maximum value, or the measurement result for the most recent predetermined number of times). Calculate variance). Then, the communication destination type determination unit 41 restricts the change in the position with the communication partner when the information indicating the change in throughput obtained for the communication partner satisfies a condition indicating that the communication partner is relatively stable. It is determined that the wireless LAN communication device has a relative position (the relative position does not change so much). Such a combination of devices includes, for example, a case where both are stationary wireless LAN communication devices, and a case where both are portable wireless LAN communication devices (both carried and moved together).

  Specifically, when information indicating communication performance such as throughput is measured for a certain communication partner over a predetermined time and the measurement result of the throughput falls below a predetermined threshold, the communication destination The type determining unit 41 determines that the communication partner is a wireless LAN communication device that does not move relatively, assuming that the information indicating the change in throughput is relatively stable, and specifies the communication partner, Information indicating that the wireless LAN communication device does not vary much in relative position with the communication partner specified by the information is associated and stored in the storage unit 12 or the storage unit 22 as a type database. In addition, although the performance information showing the communication performance is described here as an example of throughput, the information on the change of the radio wave intensity (RSSI) is referred to as the performance information, and the fluctuation of the RSSI is within a predetermined range. In some cases, the communication partner may be determined to be a wireless LAN communication device that does not move relatively. Furthermore, the throughput may be measured not only once but a plurality of times, and a statistical calculation result such as the variance may be used as performance information.

  For example, the communication destination type determination unit 41 determines that the information indicating the change in throughput is relatively unstable when the dispersion of the measurement results of multiple times exceeds a predetermined threshold, However, it is determined that the wireless LAN communication apparatus moves in a relatively large positional relationship with itself. In this case, the communication destination type determination unit 41 does not add information to the type database.

  When the upper limit setting unit 42 receives the information output from the communication destination type determination unit 41 and the wireless communication partner is the type of the control target device, the upper limit setting unit 42 receives another wireless LAN that is the partner of the wireless communication. Set the upper limit of the link rate with the communication device. In addition, when there are a plurality of types of control target device types, another wireless LAN that is a partner of each wireless communication determined to be the control target device type by a method determined in advance according to the determined type Set the upper limit of the link rate with the communication device.

  Specifically, in the present embodiment, the upper limit setting unit 42 refers to the type database stored in the storage unit 12 or the storage unit 22 and is identified by the information recorded in the type database. When transmitting information to the (control target device), the transmission throughput is repeatedly measured at predetermined timings, and the measurement results for the latest m times are specified to identify the wireless LAN communication device that is the target device. And is recorded in the storage unit 12 or the storage unit 22. Here, the measurement timing is set as, for example, a periodic timing every n seconds.

For example, every time m × n seconds elapses, the upper limit setting unit 42 (1) statistical values (average value, maximum value, minimum value, etc.) of the most recent m measurements for each wireless LAN communication device that is a control target device. )
(2) The upper limit value of the link rate for each wireless LAN communication device that is the control target device is determined using at least one of the measurement results of the transmission throughput measured last. For example, the upper limit value of the link rate is the larger of the average value (which is a moving average) Save of the measurement results of the latest m transmission throughputs and the last measured measurement result Slast of the transmission throughput, S = MAX It is determined based on the value of [Save, Slast]. Here, MAX [a, b] represents the larger value of a and b (ie, MAX [a, b] = a if a ≧ b, MAX [a, b] = b if a <b. ).

  As an example, the upper limit setting unit 42 sets the link rate upper limit value to MAX [Save, Slast] × α (α is a constant determined as appropriate, for example, 1, 1.5, 2, 2.5, 3...). To do. Actually, the link rate is selected from discrete values such as 6 Mbps, 9 Mbps, 12 Mbps,... Step by step according to the modulation method in the wireless communication units 14 and 23. Therefore, in the upper limit setting unit 42 of this embodiment, among the link rate value candidates {LR1 = 6 Mbps, LR2 = 9 Mbps, LR3 = 12 Mbps,...}, LRi ≦ MAX [Save, Slast] × α (i = 1, 2,...) Is selected as the upper limit of the link rate.

  When the upper limit setting unit 42 determines the link rate upper limit value for each target device in this way, the upper limit setting unit 42 associates the determined link rate upper limit value with information identifying the wireless LAN communication device that is the target device for each target device. And stored as an upper limit database. The upper limit value database is stored in the storage unit 12 or the storage unit 22.

  In the present embodiment, the upper limit setting unit 42 transmits information to and from a wireless LAN communication device (wireless LAN communication device that is not a type of the control target device) specified by information not recorded in the type database. In such a case, the process for determining the upper limit value of the link rate is not performed.

  The communication success / failure determination unit 43 determines the success / failure of the wireless communication when information is transmitted / received for each wireless LAN communication device that is a partner of the wireless communication. Specifically, the communication success / failure determination unit 43 repeatedly performs a test a predetermined number of times (success / failure determination number) for each wireless LAN communication device that is a wireless communication partner each time a predetermined timing arrives. Send the packet. The test packet is transmitted at a link rate determined for the wireless LAN communication apparatus (referred to as a test target) that is the destination at this time. Then, the communication success / failure determination unit 43 determines whether or not a predetermined error occurrence condition is satisfied for the transmitted test packet with an error when there is no reception confirmation response from the test target. When it is determined that the predetermined error occurrence condition is satisfied, the communication success / failure determination unit 43 determines that the communication quality with the test target is not maintained, and determines the wireless LAN communication device that is the test target. A signal indicating that the link rate should be lowered is output to the link rate control unit 44 together with the information to be specified.

  Specifically, the error occurrence condition can be a condition such that the number of times an error has occurred consecutively (the number of consecutive errors) exceeds a predetermined threshold. In addition to the number of consecutive errors, the number of error occurrences within a predetermined time, and the value obtained by dividing the time from the time when the previous error occurred to the time when the current error occurred by a predetermined reference time is below a predetermined threshold, For example, the condition relating to the error occurrence rate may be used.

  In addition, the communication success / failure determination unit 43 is linked with information specifying the wireless LAN communication device to be tested when the error occurrence condition is not satisfied (for example, the number of consecutive errors is “0” (no error)). A signal indicating that the rate can be increased is output to the link rate control unit 44.

  When the link rate control unit 44 receives a communication start request (association request or the like) from another wireless LAN communication device, the link rate control unit 44 starts generating information to be recorded in the link rate table information. Information to be identified and information representing a predetermined initial link rate are associated with each other and recorded in the link rate table information in the storage unit 12 or the storage unit 22. Here, the initial link rate may be any link rate that can be set, and may be, for example, the maximum link rate or the minimum link rate.

  Note that when link rate information determined in past communication is stored, that is, link rate information associated with information specifying another wireless LAN communication device that is the transmission source of the communication start request is stored. There is a possibility that the link rate table information in the storage unit 12 or the storage unit 22 may already be recorded at the time when the communication start request is made.

  In this case, when the link rate control unit 44 receives a communication start request (association request or the like) from another wireless LAN communication device, first, a record by past communication is stored in the storage unit 12 or the storage unit 22. Is included in the link rate table information stored in.

  That is, in this case, the link rate control unit 44 already stores the link rate information associated with the information specifying the other wireless LAN communication device in the link rate table information stored in the storage unit 12 or the storage unit 22. Find out if it is. If the link rate information is stored in the link rate table information by past communication in association with the information for specifying another wireless LAN communication device, the link rate control unit 44 ends the initialization process.

  In addition, the link rate control unit 44 associates information identifying another wireless LAN communication device with information identifying the other wireless LAN communication device if link rate information is not stored in the link rate table information, The information is recorded in the link rate table information in the storage unit 12 or the storage unit 22 in association with information representing a predetermined initial link rate.

  Further, when the communication success / failure determination unit 43 outputs a signal indicating that the link rate should be lowered together with information for specifying the wireless LAN communication device (target specifying information), the link rate control unit 44 stores the link rate control unit 44 in the storage unit 12 or the storage unit 22. The link rate information associated with the target identification information is read from the link rate table information. Further, the link rate control unit 44 refers to the upper limit value database stored in the storage unit 12 or the storage unit 22, and whether or not the link rate upper limit value associated with the target specifying information is recorded in the upper limit value database. Check out.

  Here, if the link rate upper limit value associated with the target specifying information is not recorded in the upper limit value database, the link rate control unit 44 is lower than the link rate specified by the previously read information (for example, one step). The link rate table information is updated by overwriting the information indicating the link rate with the link rate information associated with the target specifying information. If the link rate specified by the information read here is already the lowest link rate, the link rate control unit 44 ends the processing as it is (does not update the link rate information).

  Further, when the link rate upper limit value associated with the target specifying information is recorded in the upper limit value database, the link rate control unit 44 is lower than the link rate specified by the previously read information (for example, one step lower). ) It is checked whether the link rate is equal to or lower than the recorded link rate upper limit value. If the link rate is equal to or lower than the recorded link rate upper limit value, the link rate is lower than the link rate specified by the previously read information. The link rate table information is updated by overwriting the information indicating the link rate (for example, one step lower) with the link rate information associated with the target identification information. Further, if the link rate lower than the link rate specified by the previously read information (for example, one step lower) is not less than or equal to the recorded link rate upper limit value, the link of the recorded link rate upper limit value The link rate table information is updated by overwriting the information indicating the rate with the link rate information associated with the target identification information.

  Even if the link rate upper limit value associated with the target specifying information is recorded in the upper limit value database, the link rate specified by the read information is already the lowest link rate. The rate control unit 44 ends the processing as it is (does not update the link rate information).

  Here, the link rate upper limit value is referred to because the link rate upper limit value is dynamically changed, so that the link rate being used may exceed the set link rate upper limit value. In this embodiment, when it is determined that the link rate should be lowered in such a state, the link rate is set to the link rate upper limit value or less.

  Further, when the communication success / failure determination unit 43 outputs a signal indicating that the link rate can be increased together with information (target identification information) for specifying the wireless LAN communication device, the link rate control unit 44 stores the information on the storage unit 12 or the storage unit 12. The link rate information associated with the target identification information is read from the link rate table information stored in the unit 22. Further, the link rate control unit 44 refers to the upper limit value database stored in the storage unit 12 or the storage unit 22, and whether or not the link rate upper limit value associated with the target specifying information is recorded in the upper limit value database. Check out.

  Here, if the link rate upper limit value associated with the target specifying information is not recorded in the upper limit value database, the link rate control unit 44 is more than the link rate specified by the information read from the link rate table information earlier. The link rate table information is updated by overwriting information representing a high (for example, one step higher) link rate over the link rate information associated with the target specifying information. If the link rate specified by the read information has already reached the maximum link rate, the link rate control unit 44 ends the processing as it is (does not update the link rate information).

  On the other hand, when the link rate upper limit value associated with the target specifying information is recorded in the upper limit value database, the link rate control unit 44 determines that the link rate specified by the information previously read from the link rate table information is higher. Using a high (for example, one step higher) link rate as a candidate link rate, it is checked whether or not the candidate link rate is larger than the recorded link rate upper limit value. If the candidate link rate is larger than the recorded link rate upper limit value, the link rate control unit 44 ends the process as it is (does not update the link rate information).

  Further, if the candidate link rate is not greater than the recorded link rate upper limit value, the link rate control unit 44 overwrites the information indicating the candidate link rate with the link rate information associated with the target specifying information. To update the link rate table information.

  In the wireless LAN communication system of the present embodiment, the master unit 10, the relay unit 20, and the slave unit 30 are configured as described above, and operate as in the following example. In the following example, as illustrated in FIG. 3, the master unit 10 relays communication between the relay unit 20a and the slave unit 30a, and the relay unit 20a is connected to the master unit 10, the relay unit 20b, and the slave unit 30b. A case will be described as an example in which the relay device 20b performs communication with the relay device 20a and the slave device 30c. The repeater 20 of the present embodiment has an access point function unit 40 and is connected to a wireless LAN with a slave unit 30 having a client function unit, and by a client function unit or a WDS (Wireless Distribution System) function, The relay device 20 communicates with the parent device 10. That is, the relay device 20 of the present embodiment relays wireless communication between the child device 30 and the parent device 10 by the wireless LAN connection and the relay function that the relay device 20 has.

  In this example, when the base unit 10 receives an association request from the relay unit 20a, the relay unit 20a is based on the information included in the association request, and the relay unit 20a is subject to a specific link rate control, that is, the target device. It is assumed that Since the information indicating that the slave device 30a is the target device is not included in the association request, the master device 10 does not determine that the slave device 30a is the target device.

  In addition, when the relay device 20a receives the association request from the relay device 20b, the relay device 20b is a target of a specific link rate control, that is, a target device, based on information included in the association request. Judge. The relay device 20a does not determine that the child device 30b is the target device because the information indicating that the child device 30b is the target device is not included in the association request. Further, the relay device 20b does not determine that the child device 30c is the target device because the information indicating that the child device 30c is the target device is not included in the association request.

In this example, when information is transmitted to the repeater 20a, the base unit 10 repeatedly measures its transmission throughput every second, and the measurement results for the last three times are obtained as a wireless LAN as the target device. The information is recorded in the storage unit 12 in association with information specifying the communication device. The master unit 10 also obtains the average value Save of the measurement results for the most recent three times for the relay device 20a, which is the target device, for example, every 2 seconds after at least three measurement results are obtained.
(2) Of the last measured transmission throughput measurement results Slast, the larger value of S = MAX [Save, Slast] is used to set the link rate upper limit value LRlimit for the relay 20a to LRlimit = MAX [Save, Slast] × α (α is set to 1.5, for example), and among the possible link rate value candidates {LR1 = 6 Mbps, LR2 = 9 Mbps, LR3 = 12 Mbps,. The maximum LRi is selected as the link rate upper limit. For example, it is assumed here that the upper limit of the link rate is set to 36 Mbps.

  Then, base unit 10 associates the information specifying relay device 20a with the determined link rate upper limit value 36 Mbps, and stores it in storage unit 12 as an upper limit value database. In addition, since the parent device 10 is not a target device for the child device 30a, the upper limit value of the link rate is not determined.

The repeater 20a repeatedly measures the transmission throughput every second when information is transmitted to the repeater 20b, and specifies the wireless LAN communication device that is the target device based on the latest three measurements. The information is recorded in the storage unit 22 in association with the information to be performed. The repeater 20a also obtains the average value Save of the latest three measurements for the repeater 20b as the target device, for example, every 2 seconds after at least three measurement results are obtained.
(2) Of the last measured transmission throughput measurement results Slast, the larger value of S = MAX [Save, Slast] is used to set the link rate upper limit value LRlimit for the repeater 20b to LRlimit = MAX [Save, Slast] × α (α is set to 1.5, for example), and among the possible link rate value candidates {LR1 = 6 Mbps, LR2 = 9 Mbps, LR3 = 12 Mbps,. The maximum LRi is selected as the link rate upper limit.

  Then, the relay machine 20a associates the information specifying the relay machine 20b with the determined link rate upper limit value LRi and stores it in the storage unit 22 as an upper limit value database. Moreover, since the relay machine 20a is not a target apparatus about the subunit | mobile_unit 30b, a link rate upper limit is not defined.

  Thereafter, base unit 10 transmits a test packet a predetermined number of times to relay unit 20a. This test packet is performed at a link rate (for example, 12 Mbps) determined with the repeater 20a at this time. Here, when no error occurs in the transmission of the test packet from the parent device 10 to the relay device 20a, the parent device 10 determines that the link rate can be increased, and the current link rate is 12 Mbps, for example. A candidate is a link rate of 18 Mbps which is one step higher. Since this candidate link rate of 18 Mbps is lower than the link rate upper limit 36 Mbps determined for the repeater 20a, the master unit 10 sets the link rate for the repeater 20a to 18 Mbps as illustrated in FIG. 4A. Change (P).

  After that, the base unit 10 confirms whether or not an error has occurred by sending this test packet (determination of success or failure of communication) to the relay unit 20a at a predetermined timing. When no error occurs, the base rate is set. Increase from 18 Mbps to 24 Mbps to 36 Mbps. When the link rate is 36 Mbps and the link rate is 36 Mbps, if no error has occurred as a result of the communication success / failure determination, the base unit 10 considers the link rate 48 Mbps, for example, one step higher than the link rate 36 Mbps at that time as a candidate. To do. However, since the candidate link rate 48 Mbps is larger than the link rate upper limit 36 Mbps determined for the repeater 20a, the master unit 10 uses the link rate for the repeater 20a as illustrated in FIG. 4A. Is not changed from 36 Mbps (Q).

  On the other hand, for the slave unit 30a, the master unit 10 similarly checks whether or not an error has occurred by sending a test packet (judgment of communication success / failure) at every predetermined timing. For example, when the initial link rate is 12 Mbps, and no error occurs in the subsequent communication success / failure determination, the base unit 10 sets the wireless communication link rate for the handset 30a to 12 Mbps → 18 Mbps → 24 Mbps. → Increase to 36 Mbps → 48 Mbps → 54 Mbps. Here, since the upper limit value of the link rate is not defined for the slave unit 30a, the master unit 10 can communicate with the slave unit 30a up to the maximum link rate (for example, 54 Mbps) unless an error occurs. The communication link rate is increased (FIG. 4B).

  Similarly, in the repeater 20a, a link rate upper limit value is set for the repeater 20b, and communication is performed by setting a link rate lower than the link rate upper limit value with the link rate upper limit value as a limit (FIG. 4). (Similar to (a)) However, for the slave unit 30b, communication is performed by setting the link rate according to the determination of the success or failure of the communication without setting the link rate upper limit value as in the conventional case (FIG. 4B). ) As in the example). Further, similarly to the relay device 20b, the slave device 30c performs communication without setting a link rate upper limit value and setting a link rate according to the determination of communication success / failure.

[Example of different success / failure judgments depending on the type of communication partner]
In addition, as described above, the communication success / failure determination unit 43 determines the success / failure of the wireless communication when transmitting / receiving information for each wireless LAN communication apparatus that is the partner of the wireless communication. The number of test packet transmissions (success / failure determination times) may be made different depending on the type of wireless LAN communication apparatus that is the counterpart of wireless communication.

  For example, the communication success / failure determination unit 43 sequentially selects wireless LAN communication apparatuses that are wireless communication counterparts as determination targets each time a predetermined timing arrives. When the determination target is selected, the communication success / failure determination unit 43 refers to the type database stored in the storage unit 12 or the storage unit 22, and whether the information for specifying the selected determination target is recorded in the type database. It is checked whether or not (the determination target is the target device).

  When the information specifying the determination target selected here is not recorded in the type database (the determination target is not the target device: type “1”), the communication success / failure determination unit 43 sets the success / failure determination count as the target device. A predetermined number of times N1 is assumed. When the information for specifying the selected determination target is recorded in the type database (the determination target is the target device: type “2”), the communication success / failure determination unit 43 sets the success / failure determination count for the target device. The number of times N2 is set in advance. Here, the numbers N1 and N2 are both integers of 2 or more. N1 <N2 may be satisfied.

  Then, the communication success / failure determination unit 43 repeatedly transmits a test packet to the wireless LAN communication apparatus selected as the determination target for the predetermined success / failure determination times. The test packet is transmitted at a link rate determined for the wireless LAN communication apparatus (referred to as a test target) that is the destination at this time. Then, the communication success / failure determination unit 43 determines the number of times that an error has occurred continuously (the number of consecutive errors) for the test packet sent out as an error when there is no reception confirmation response from the test target. The communication success / failure determination unit 43 determines that the communication quality with the test target is not maintained when the number of consecutive errors exceeds a predetermined error count threshold, and determines the wireless LAN communication device that is the test target. A signal indicating that the link rate should be lowered is output together with the specified information (link rate lowering control).

  Further, the communication success / failure determination unit 43 links with information specifying the wireless LAN communication device to be tested when the continuous error count is “0” (no error) or when the error count threshold is not exceeded. A signal indicating that the rate can be increased is output (link rate increase control).

  Here, the same number N1 or N2 is used for determining whether to lower the link rate and determining whether it can be increased, but the present embodiment is not limited to this. For example, the communication success / failure determination unit 43 repeatedly transmits a test packet to the wireless LAN communication apparatus selected as the determination target for the predetermined number of success / failure determinations. During this transmission, the latest M times (M is N1, N2,... The number of times an error has occurred consecutively (the number of consecutive errors) is examined for a test packet of less than the minimum number of test packets. The communication success / failure determination unit 43 determines that the communication quality with the test target is not maintained when the number of consecutive errors exceeds a predetermined error count threshold, and determines the wireless LAN communication device that is the test target. A signal indicating that the link rate should be lowered may be output together with information to be specified (link rate lowering control is performed).

  In this case, the communication success / failure determination unit 43 selects the wireless LAN communication device as the test target when there is no error in all the test packets of the determined success / failure determination times for the wireless LAN communication device selected as the determination target. A signal indicating that the link rate can be increased together with the information to be specified may be output (link rate increase control is performed).

  According to this example, although different success / failure determination times (N1, N2,...) Are determined according to the type of the other party of the wireless communication, the determination as to whether or not to lower the link rate is performed regardless of the type of the other party. When a communication error occurs during a predetermined M times (M ≦ N1 <N2 <...) Determined in (1), the lowering control is performed. This is based on the condition that no error occurs in communication by continuing the success / failure determination times (N1, N2,...) Different from each other according to the type of the other party.

  When configured in this way, each wireless LAN communication device in the example shown in FIG. 3 operates as follows. In this case as well, when the base unit 10 receives the association request from the relay unit 20a, the relay unit 20a is based on the information included in the association request, that is, the target of the specific link rate control, that is, the target Since it is determined that the device is a device, a link rate upper limit value is determined for the relay device 20a (eg, the link rate upper limit is determined to be 36 Mbps here). In addition, since the information indicating that the child device 30a is the target device is not included in the association request, the parent device 10 does not determine that the child device 30a is the target device.

  Similarly, when the relay device 20a receives an association request from the relay device 20b, based on the information included in the association request, the relay device 20b is a specific link rate control target, that is, a target device. Since it is determined that there is a link rate, a link rate upper limit value is determined for the repeater 20b. Further, since the information indicating that the slave device 30b is the target device is not included in the association request, the relay device 20a does not determine that the slave device 30b is the target device. Further, the relay device 20b does not determine that the child device 30c is the target device because the information indicating that the child device 30c is the target device is not included in the association request.

  When the predetermined timing comes after the communication is started, the base unit 10 sequentially selects the relay unit 20a and the slave unit 30a, which are wireless communication counterparts, as determination targets. For example, the base unit 10 first determines the repeater 20a as a determination target. Then, the base unit 10 refers to the type database stored in the storage unit 12, and whether the information for specifying the selected relay device 20a as the determination target is recorded in the type database (the relay device as the determination target). 20a is a target device).

  Here, since the relay device 20a is a target device, the master device 10 sets the number of success / failure determinations to a predetermined number N2 (for example, 10 times) for the target device.

  This test packet is performed at a link rate (for example, 12 Mbps) determined with the repeater 20a at this time. Here, when no error occurs in the transmission of the test packet N2 times from the base unit 10 to the relay unit 20a, the base unit 10 determines that the link rate can be increased, and the current link rate is 12 Mbps. For example, a link rate of 18 Mbps, which is one step higher, is used as a candidate. Since this candidate link rate of 18 Mbps is lower than the link rate upper limit 36 Mbps determined for the repeater 20a, the master unit 10 sets the link rate for the repeater 20a to 18 Mbps as illustrated in FIG. 4A. Change (P).

  Further, in the transmission of the test packet from the parent device 10 to the relay device 20a, when an error occurs in three times, for example, a predetermined number M (M <N2), the parent device 10 The link rate for 20a is controlled to decrease, and is changed to, for example, 9 Mbps, which is a link rate one step lower than the current link rate of 12 Mbps.

  Next, base unit 10 selects slave unit 30a that is the counterpart of wireless communication as a determination target. The parent device 10 refers to the type database stored in the storage unit 12, and whether the information for specifying the selected child device 30a as the determination target is recorded in the type database (the child device 30a as the determination target). Is the target device).

  Here, since the child device 30a is not the target device, the parent device 10 sets the success / failure determination frequency to a predetermined number N1 (for example, three times) for those that are not the target device.

  This test packet is performed at a link rate (for example, 12 Mbps) determined with the handset 30a at this time. Here, when no error occurs in the transmission of the test packet from the parent device 10 to the child device 30a, the parent device 10 determines that the link rate can be increased, and the current link rate is 12 Mbps, for example. Change to a higher link rate of 18 Mbps.

  Further, in the transmission of the test packet from the parent device 10 to the child device 30a, when an error occurs in three times, for example, a predetermined number M (M ≦ N1), the parent device 10 The link rate for 30a is lowered and changed to 9 Mbps, which is a link rate that is one step lower than the current link rate of 12 Mbps, for example.

  Thereafter, the base unit 10 confirms whether or not an error has occurred due to the transmission of the test packet (determination of communication success / failure) at each predetermined timing with respect to each of the relay unit 20a and the slave unit 30a. With regard to the repeater 20a, if no error occurs in all N2 test packets in each communication success / failure determination, the link rate is gradually increased from 18 Mbps to 24 Mbps to 36 Mbps. When the link rate is 36 Mbps and the link rate is 36 Mbps, if no error has occurred as a result of the communication success / failure determination, the base unit 10 considers the link rate 48 Mbps, for example, one step higher than the link rate 36 Mbps at that time as a candidate. To do. However, since the candidate link rate 48 Mbps is larger than the link rate upper limit 36 Mbps determined for the repeater 20a, the master unit 10 uses the link rate for the repeater 20a as illustrated in FIG. 4A. Is not changed from 36 Mbps (Q).

  On the other hand, if no error occurs in all the N1 test packets in the determination of the success or failure of the communication with respect to the slave unit 30a, the master unit 10 changes the link rate of wireless communication with respect to the slave unit 30a to 12 Mbps → 18 Mbps. → Increases to 24 Mbps → 36 Mbps → 48 Mbps → 54 Mbps. Here, since the upper limit value of the link rate is not defined for the slave unit 30a, the master unit 10 can communicate with the slave unit 30a up to the maximum link rate (for example, 54 Mbps) unless an error occurs. The communication link rate is increased (FIG. 4B).

  Similarly, in the repeater 20a, a link rate upper limit value is set for the repeater 20b. Then, the repeater 20a transmits N2 test packets in determining success or failure of communication with the repeater 20b, and determines that the link rate can be increased when no error occurs in all of them. Communication is performed by setting a link rate equal to or lower than the link rate upper limit value with the link rate upper limit value as the limit (similar to FIG. 4A). When an error occurs within a predetermined number M (M <N2), the repeater 20a controls to lower the link rate for the repeater 20b and lowers the link rate.

  In addition, the relay device 20a does not provide a link rate upper limit value for the child device 30b. The repeater 20a transmits the test packet N1 times (in this case, N1 <N2 for example) in determining the success or failure of the communication to the slave unit 30b. It is determined that it can be increased, and communication is performed by setting a link rate that is increased by one step (similar to FIG. 4B). When an error occurs within a predetermined number of times M (M <N2), the repeater 20a controls to lower the link rate for the child device 30b and lowers the link rate.

  Similarly, the relay unit 20b does not set a link rate upper limit value for the slave unit 30c, and performs communication by setting the link rate in the same manner as the determination of success or failure of the relay unit 20a for the slave unit 30b. It becomes.

  This operation changes the link rate change frequency according to the type of wireless communication partner (the slave unit will increase the link rate if there is no error with relatively few test packets, while the repeater will The link rate will not increase unless an error occurs in a large number of test packets), and the link rate will be set according to the situation of each type of wireless communication partner, contributing to the stabilization of wireless communication. .

[Example of controlling the rate of increase of the link rate]
Further, in this example of the present embodiment, the success / failure determination count may be varied based on not only the type of communication partner but also the link rate upper limit value determined for the communication partner.

  In this example, the communication success / failure determination unit 43 operates as follows. That is, every time a predetermined timing arrives, the communication success / failure determination unit 43 sequentially selects a wireless LAN communication device that is a partner of wireless communication as a determination target. When the determination target is selected, the communication success / failure determination unit 43 refers to the type database stored in the storage unit 12 or the storage unit 22, and whether the information for specifying the selected determination target is recorded in the type database. It is checked whether or not (the determination target is the target device).

  When the information specifying the determination target selected here is not recorded in the type database (the determination target is not the target device: type “1”), the communication success / failure determination unit 43 sets the success / failure determination count as the target device. A predetermined number of times N1 is assumed.

  When the information for specifying the selected determination target is recorded in the type database (the determination target is the target device: type “2”), the communication success / failure determination unit 43 sets the success / failure determination count for the target device. The upper limit value database in association with the predetermined number N2, the link rate L determined for the wireless LAN communication device that is the determination target at that time, and information that identifies the wireless LAN communication device that is the determination target Is determined based on the link rate upper limit value LRlimit recorded in

Specifically, here, the communication success / failure determination unit 43 determines the success / failure determination count N for this determination target,
N = [N2 × (1-LRlimit / L × γ)]
And Here, [*] is a maximum integer value not exceeding *, and γ is a coefficient determined as appropriate.

In an example of the present embodiment, N2 = 10 and γ = 0.1. In this case, for example, if the link rate L = 9 Mbps determined for the target device at the time of processing and the link rate upper limit value LRlimit = 48 Mbps,
N = [3 × (1-48 / 9 × 0.1)] = 4
It becomes. Also, assuming that the link rate upper limit value LRlimit = 48 Mbps and the link rates L determined for the target device at the time of processing are 12 Mbps, 18 Mbps,.
N = [3 × (1-48 / 12 × 0.1)] = 6
N = [3 × (1-48 / 18 × 0.1)] = 7
...
N = [3 × (1-48 / 36 × 0.1)] = 8
It becomes. Here, the numbers N1 and N2 are both integers of 2 or more, and N1 <N2.

  The communication success / failure determination unit 43 repeatedly transmits a test packet to the wireless LAN communication device selected as the determination target for the predetermined success / failure determination times. The test packet is transmitted at a link rate determined for the wireless LAN communication apparatus (referred to as a test target) that is the destination at this time. Then, the communication success / failure determination unit 43 determines the number of times that an error has occurred continuously (the number of consecutive errors) for the test packet sent out as an error when there is no reception confirmation response from the test target. The communication success / failure determination unit 43 determines that the communication quality with the test target is not maintained when the number of consecutive errors exceeds a predetermined error count threshold, and determines the wireless LAN communication device that is the test target. A signal indicating that the link rate should be lowered is output together with the specified information (link rate lowering control).

  Further, the communication success / failure determination unit 43 can increase the link rate together with information for specifying the wireless LAN communication device to be tested when the number of consecutive errors is “0” (no error). A signal is output (link rate increase control).

  In this case as well, the same number N1 or N (the number determined using the above N2, L, LRlimit) is used in the determination as to whether or not the link rate should be lowered and the determination as to whether or not the link rate can be raised. Instead of determining whether or not to perform the descending control, the error is continuously detected for the most recent M times (M is equal to or less than the minimum of N1, N2,...) While sending the test packet. When the number of occurrences (number of consecutive errors) exceeds a predetermined error count threshold, it is determined that the communication quality with the test target is not maintained, and the wireless LAN communication device that is the test target is specified A signal indicating that the link rate should be lowered may be output together with the information to be performed (link rate lowering control is performed).

  According to this example of the present embodiment, when there is no error in communication with the wireless LAN communication device that is the target device, if the link rate is 9 Mbps, the link rate is 4 times unless an error occurs. If the link rate is 12 Mbps, the link rate is increased by one step and becomes 18 Mbps unless an error occurs continuously six times. According to this, the base unit 10 or the relay unit 20 performs control so as to increase the link rate more rapidly as the difference between the current link rate and the link rate upper limit value increases (there is a margin to the link rate upper limit value). It will be. An example of such control is not limited to the above-described method. For example, the error frequency threshold when determining whether or not to perform increase control increases as the difference between the current link rate and the link rate upper limit value increases. (The link rate is controlled to increase if the number of times that no error has occurred falls below the error count threshold in this case). Further, instead of the above-described calculation, the number of success / failure determinations may be determined in advance according to the link rate at the time of processing.

[Example of not setting the link rate upper limit]
As explained so far, in an example of this embodiment,
(1) The wireless LAN communication device is classified into a device such as a relay device that is arranged with a fixed position and a device that is assumed to move such as a slave device.
(2) Depending on the type, a link rate upper limit is set,
(3) For each wireless LAN communication device, determine whether or not to increase the link rate by determining the success or failure of the wireless communication by the number of times of wireless communication success / failure determination determined according to the type of the wireless LAN communication device;
(4) In the case of increasing control, if a link rate upper limit value is provided for the wireless LAN communication device targeted for increasing control, the increasing control is performed in a range of a link rate lower than the link rate upper limit value.

  However, the present embodiment is not limited to this. For example, the link rate upper limit value may not be provided in any type.

  In this case, the control unit 11 of the base unit 10 and the control unit 21 of the relay device 20 according to the present embodiment operate according to the programs stored in the storage unit 12 or the storage unit 22, respectively, and are illustrated in FIG. Thus, the function as the access point function unit 40 is realized. The access point function unit 40 performs an operation as an access point function. In this embodiment, the access point function unit 40 functions as a communication destination type determination unit 41, a communication success / failure determination unit 43, and a link rate control unit 44 '. It will be. In addition, the same code | symbol is attached | subjected about the structure which performs the operation | movement similar to what was already demonstrated, and repeated description is abbreviate | omitted.

  In this example, the link rate control unit 44 'operates when receiving a communication start request (association request or the like) from another wireless LAN communication device, and a signal indicating that the link rate should be lowered from the communication success / failure determination unit 43. The operation when receiving the signal is the same as that of the link rate control unit 44 described above, but the operation when receiving the signal indicating that the link rate can be increased from the communication success / failure determination unit 43 is as follows. Slightly different.

  That is, when the communication rate determination unit 43 outputs a signal indicating that the link rate can be increased together with information (target specifying information) for specifying the wireless LAN communication device, the link rate control unit 44 ′ outputs to the storage unit 12. The link rate information associated with the target identification information is read from the stored link rate table information.

  Then, the link rate control unit 44 ′ uses the link rate associated with the target specifying information to indicate the link rate higher (for example, one step higher) than the link rate specified by the information read from the link rate table information. The link rate table information is updated by overwriting the information. If the link rate specified by the read information has already reached the maximum link rate, the link rate control unit 44 'ends the process as it is (does not update the link rate information).

  That is, in this example, since the upper limit value database is not set, the link rate control unit 44 'performs an operation that does not consider the link rate upper limit value.

[Operation other than test packet]
Further, in the examples so far, when the communication success / failure determination unit 43 determines the success / failure of communication, the test packet is transmitted for determining the success / failure of communication. However, the present embodiment is not limited to this, The success or failure of communication may be determined using a data packet including user data. Specifically, the wireless LAN communication apparatus according to the present embodiment retransmits the data packet when communication of the data packet including the user data fails, and the retransmitted data packet is the above-described test packet. Instead. When performing retransmission, the setting of link rate information may be changed so that retransmission is performed using a link rate lower than the link rate at that time (for example, one step lower).

  Further, the communication success / failure determination unit 43 may obtain performance information on communication throughput with a communication partner and output information for setting a link rate based on the performance information. For example, the communication success / failure determination unit 43 performs the following processing for each wireless LAN communication device that is a communication partner. That is, the communication success / failure determination unit 43 measures the throughput of communication with the wireless LAN communication apparatus that is the communication partner that repeatedly transmits and receives information at predetermined timings, and stores the latest multiple times. . Then, the communication success / failure determination unit 43 obtains, as performance information, a predetermined statistical calculation (for example, an average or the like) for the measurement result of the throughput of the latest multiple times stored for each wireless LAN communication device that is the communication partner. The performance information may be the last measured communication throughput itself.

  The communication success / failure determination unit 43 calculates the ratio R = TP between the performance information TP calculated for each wireless LAN communication device that is the partner of wireless communication and the current link rate LR set for the wireless LAN communication device. Find / LR.

  Further, a plurality of threshold values Rth1, Rth2 (Rth1> Rth2> ...) are determined in advance for the ratio R, and information indicating how many steps the link rate is increased or decreased is stored in association with each threshold value. Stored in the unit 12 or the storage unit 22. The communication success / failure determination unit 43 compares the ratio R obtained for each wireless LAN communication apparatus that is the counterpart of wireless communication with this threshold value, and obtains the maximum threshold value Rthn that does not exceed this ratio. The information indicating that the link rate should be increased or decreased by the level specified by the information associated with the obtained threshold value Rthn (for example, the level LS) is the counterpart of the corresponding wireless communication. Output together with information specifying the wireless LAN communication device.

  In this example, when the link rate control units 44 and 44 ′ increase or decrease the link rate, the link rate increases by the instructed stage LS based on the instruction input from the communication success / failure determination unit 43. Or try to descend. At this time, if the level is increased by s <LS, if the link rate upper limit value (if set) or the upper limit of the link rate that can be set is reached, the link rate control units 44, 44 'are included in the above instructions. The link rate related to communication with the wireless LAN communication device specified by the information to be set is set to the link rate upper limit value (if set) or the upper limit of the link rate that can be set.

  Similarly, if the link rate control units 44 and 44 'reach the lower limit of the link rate that can be set if the step s <LS is lowered at this time, the wireless LAN communication specified by the information included in the instruction is performed by the link rate control units 44 and 44'. The link rate related to communication with the device is set to the lower limit of the link rate that can be set.

[Number of types]
In addition, as described above, even for a device to be controlled, a link rate upper limit value setting method is divided into a plurality of types according to differences in communication speed fluctuation factors such as communication path conditions, and the success or failure of communication success / failure determination. The number of times may be controlled. As an example, in this embodiment, it is relatively easy to generate an error as determined from past communication results arranged at a place where the communication partner is fixed (number and frequency of link rate lowering control (per unit time). (The number of times) is equal to or greater than a threshold value) The control may be performed (the method of setting the upper limit value is changed) according to the type of control target device and the type of control target device that is not.

[Apply to uplink]
In the examples so far, the link rate upper limit value based on the communication (downlink) from the parent device to the relay device, the relay device on the parent device side to another relay device, the parent device or the relay device to the child device, The number of successful / unsuccessful judgments and the actual link rate were set, but in this embodiment, uplink communication such as communication from the slave unit to the master unit or relay unit is also used for uplink communication. Based on this, the link rate upper limit value, the number of success / failure determinations, the actual link rate, etc. may be determined.

10 base unit, 11 control unit, 12 storage unit, 13 wired communication unit, 14 wireless communication unit, 20 relay unit, 21 control unit, 22 storage unit, 23 wireless communication unit, 30 slave unit, 40 access point function unit, 41 Communication destination type determination unit, 42 upper limit setting unit, 43 communication success / failure determination unit, 44, 44 ′ link rate control unit.

Claims (5)

A wireless LAN communication system comprising a plurality of wireless LAN communication devices, each of which has at least one of an access point function unit and a client function unit, and is communicably connected to each other,
The wireless LAN communication apparatus having the access point function unit is:
Determining means for determining the type of the first wireless LAN communication apparatus that is a communication partner;
Control of the link rate of the wireless communication with the first wireless LAN communication device according to different determination criteria depending on whether or not the determination means determines that the first wireless LAN communication device is a type of the device to be controlled. A determination means for determining whether or not to perform,
Control means for controlling the link rate when the determination means determines that the link rate should be controlled;
A wireless LAN communication system. A wireless LAN communication device that has an access point function unit and is communicably connected to a first wireless LAN communication device that is another wireless LAN communication device,
Determining means for determining a type of the first wireless LAN communication device;
Control of the link rate of the wireless communication with the first wireless LAN communication device according to different determination criteria depending on whether or not the determination means determines that the first wireless LAN communication device is a type of the device to be controlled. A determination means for determining whether or not to perform,
Control means for controlling the link rate when the determination means determines that the link rate should be controlled;
A wireless LAN communication device. The wireless LAN communication device according to claim 2,
The determination criterion is a determination criterion for determining whether or not to control the link rate of the wireless communication based on whether or not the rate of occurrence of communication errors with the first wireless LAN communication device is equal to or less than a predetermined rate. ,
The predetermined ratio in the determination criterion when the determination unit determines that the first wireless LAN communication device is the control target device is determined that the first wireless LAN communication device is not the control target device. A wireless LAN communication device lower than the predetermined ratio in the case of being performed. The wireless LAN communication device according to claim 2 or 3,
The determination criterion is whether or not the number of times that a communication error with the first wireless LAN communication device does not continuously occur is a predetermined number or more,
The predetermined number of times in the determination criterion when the determination unit determines that the first wireless LAN communication device is the control target device is that the first wireless LAN communication device is not the control target device. A wireless LAN communication device that is more than the predetermined number of times determined. A wireless LAN communication apparatus that has an access point function unit and is communicably connected to a first wireless LAN communication apparatus that is another wireless LAN communication apparatus, and is different from the first wireless LAN communication apparatus A wireless LAN communication device that is communicably connected to a second wireless LAN communication device having an access point function unit,
Determining means for determining a type of the first wireless LAN communication device;
Control of the link rate of the wireless communication with the first wireless LAN communication device according to different determination criteria depending on whether or not the determination means determines that the first wireless LAN communication device is a type of the device to be controlled. A determination means for determining whether or not to perform,
Control means for controlling the link rate when the determination means determines that the link rate should be controlled;
Relay means for relaying communication between the first wireless LAN communication device and the second wireless LAN communication device;
A wireless LAN communication device.

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