JP6683916B2 - Wireless device and wireless communication system - Google Patents

Description

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

  In communication using a wireless LAN, Patent Document 1 discloses a technique for efficiently and flexibly allocating a radio frequency in order to solve a problem such as interference between radio communication devices. The technology disclosed in Patent Document 1 discloses that the frequency used for intra-area communication is avoided and the frequency for inter-area communication is determined.

JP, 2003-152732, A

  However, the conventional wireless LAN system described above has a problem in that the usage status of the wireless frequency band of each wireless LAN communication device is not taken into consideration. Therefore, in a network including a wireless LAN master device and a wireless LAN relay device, when trying to select a frequency band used for communication between the wireless LAN master device and the wireless LAN relay device, there is not always a lot of space (communication In some cases, the (efficient) frequency band was not allocated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wireless device and a wireless communication system capable of performing communication in a wireless LAN communication device or the like in consideration of the usage status of each frequency band. One of

  The present invention, which solves the problems of the conventional example, is a wireless device that communicates with another wireless device using any one of a plurality of frequency bands, and the wireless device itself or the other wireless device. Means for acquiring information indicating the usage status of each frequency band in at least one of the above, and means for predicting congestion of the frequency band from the usage status of each frequency band represented by the acquired information to obtain prediction result information And a means for selecting a frequency band used for communication with the other wireless device based on the prediction result information, and a means for communicating with the other wireless device using the selected frequency band. It is to prepare.

  By doing so, it is possible to select the frequency band used for communication between the wireless devices while considering the congestion for each frequency band.

  Further, the means for obtaining the information indicating the usage state for each frequency band is a slave unit connected to the target device for each frequency band of the target device, using at least one of the wireless device itself or the other wireless device as the target device. , The type of slave device connected to the target device, and the content of communication between the target device and the slave device connected to the target device.

  From this, the frequency band to which a relatively large number of cordless handsets are connected, the frequency band in which communication using multiple channels is performed, and the cordless handset that is predicted to perform a relatively large amount of communication are connected. It is possible to perform control such as selecting a frequency band used for communication with the wireless LAN repeater while avoiding the existing frequency band.

  Further, when the wireless device itself or at least one of the other wireless devices is transmitting / receiving video information or audio information to / from a slave unit, the frequency used for transmitting / receiving the video information or audio information. The means for outputting the information specifying the band and selecting the frequency band may select a frequency band different from the frequency band specified by the output information.

  As a result, it is possible to perform control such as selecting a frequency band used for communication between wireless devices while avoiding a frequency band or the like to which a slave device predicted to perform communication with a relatively large amount of communication is connected.

  Further, the selection of the frequency band based on the prediction result information may be performed at a predetermined timing. Furthermore, the predetermined timing is at least one of a timing for connecting to the other wireless device, a timing for every fixed time, and a timing for detecting communication in which a communication amount (data amount per unit time) exceeds a threshold value. May be included.

  Further, according to one embodiment of the present invention, a first wireless device and a second wireless device which can communicate with each other using any one of a plurality of frequency bands are provided, and the first wireless device and the second wireless device are provided. Each of the wireless devices is a wireless communication system that communicates with a child device using any one of the plurality of frequency bands, and for each frequency band in at least one of the first wireless device and the second wireless device. Means for obtaining information indicating the usage state of the frequency band from the usage state for each frequency band represented by the acquired information, means for obtaining prediction result information by predicting congestion of the frequency band, and the prediction result information Means for selecting a frequency band to be used for communication between the first wireless device and the second wireless device, based on which the first wireless device and the second wireless device are located between the first wireless device and the second wireless device. Selected In which it was decided to perform communication using a frequency band.

  By doing so, the frequency band used for communication between the wireless devices can be selected while considering the usage status of each frequency band.

  According to the present invention, it is possible to select a frequency band used for communication between wireless devices while considering congestion for each frequency band.

It is a block diagram showing an example of a wireless communication system according to an embodiment of the present invention. It is explanatory drawing showing the example of an outline of the communication status information which the wireless LAN communication device with which the wireless communication system which concerns on embodiment of this invention is equipped. It is a functional block diagram showing the example of the main | base station of the radio | wireless communications system which concerns on embodiment of this invention. It is a functional block diagram showing the example of the repeater of the radio | wireless communications system which concerns on embodiment of this invention. It is explanatory drawing showing the example of the response information which the main | base station of the wireless communication system which concerns on embodiment of this invention produces | generates. It is a flowchart figure showing the operation example of the radio | wireless communications system 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 communication system according to the present embodiment includes a first wireless device 10, a second wireless device 20, and a slave (a wireless communication device having a function as a client function unit). Client device 30 of FIG. In the example of FIG. 1, a plurality of client devices 30a, 30b, ... Are shown as the client device 30. Hereinafter, when it is not necessary to distinguish between the client devices 30a, 30b, ...

  Both the first wireless device 10 and the second wireless device 20 function as access points. Further, the first wireless device 10 and the second wireless device 20 communicate with other wireless devices by using channels belonging to any one of a plurality of frequency bands. Here, the frequency band is a predetermined frequency range, and a plurality of channels (wireless communication paths for performing communication for implementation) are set in this frequency range. In the example of the present embodiment, the first wireless device 10 and the second wireless device 20 comply with standards such as IEEE802.11b, 11a, 11g, 11n, and 11ac, and have a wireless frequency band of 2.4 GHz band and 5 GHz band. Shall be used. In this example, the specific configuration of the plurality of channels included in each radio frequency band is widely known, and thus detailed description thereof is omitted here.

  In addition, in the example of the present embodiment, the first wireless device 10 includes a control unit 11, a storage unit 12, a wired LAN interface unit 13, and a wireless LAN interface unit 14, as illustrated in FIG. 1. The second wireless device 20 includes a control unit 21, a storage unit 22, and a wireless LAN interface unit 23.

  Here, the control unit 11 of the first wireless device 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 performs an operation for realizing the access point function of the wireless LAN. In the present embodiment, as shown in FIG. 2, the control unit 11 includes a second wireless device 20 to / from which the wireless LAN interface unit 14 wirelessly transmits / receives data (which is a communication partner), and the like. Information for identifying a child device such as the client device 30 (information for identifying a child device communicating with a wireless LAN, eg, a MAC address of each child device) is used for communication with the respective child device. It is stored in the storage unit 12 as the communication status information in association with the information for specifying the channel. In addition, the control unit 11 responds to the request from the second wireless device 20, and provides the information regarding the communication status information stored in the storage unit 12. The operation of the control unit 11 will be described later.

  When the wired LAN interface unit 13 or the wireless LAN interface unit 14 receives the data addressed to the child device specified by the information included in the stored communication status information, the control unit 11 wirelessly transmits the received data. The data is output to the LAN interface unit 14 and sent to the destination child device. When the control unit 11 receives data from any of the slaves that is not addressed to the other slaves specified by the stored information, the control unit 11 outputs the received data to the wired LAN interface unit 13, and the wired LAN interface unit 13 outputs the received data. The data is transmitted via the LAN.

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

  The wired LAN interface unit 13 is connected to the wired LAN. The wired LAN interface unit 13 receives information via the wired LAN and outputs the received information to the control unit 11. Further, the wired LAN interface unit 13 sends out the instructed information via the wired LAN according to the instruction input from the control unit 11.

  The wireless LAN interface unit 14 includes at least one wireless LAN interface module 140a, b, ... (Hereinafter, when it is not necessary to distinguish between the wireless LAN interface modules 140a, b, .. Have The wireless LAN interface module 140 wirelessly communicates with other wireless devices such as the second wireless device 20 and the client device 30 or a slave device using a specified channel belonging to a specified frequency band. Then, the information received from these other wireless devices and slaves is output to the control unit 11. Further, the wireless LAN interface module 140 sends the instructed information to the instructed slave unit using the above-specified channel in accordance with the instruction input from the control unit 11. In the present embodiment, the wireless LAN interface module 140 of the wireless LAN interface unit 14 is assumed to be capable of wireless communication on any channel that belongs to any of a plurality of frequency bands. Specifically, in the following example, the wireless LAN interface module 140 uses the 2.4 GHz band and the 5 GHz band as the wireless frequency band in accordance with the standards such as IEEE 802.11b, 11a, 11g, 11n, and 11ac, which are one of the wireless LAN standards. These frequency bands are referred to as standard frequency bands) when making a particular distinction. In this example, the 2.4 GHz radio frequency band includes a plurality of channels from 1 to 14 and the 5 GHz radio frequency band includes each channel classified into W52 / 53/56/58 type. In the following, in order to simplify the description, the frequency bands are standard frequency bands such as the 2.4 GHz band and the 5 GHz band, but the present embodiment is not limited to this, and the frequency bands are 5 GHz W52 and 5 GHz. W53 and a frequency band for each type such as ... (Hereinafter referred to as a type frequency band when particularly distinguished). Further, the standard frequency band and the type frequency band may be mixed and used. For example, in the present embodiment, the frequency bands may be distinguished from each other, such as 2.4 GHz, 5 GHz W52, 5 GHz W53, and so on. In other words, the frequency band in this embodiment refers to a range of frequencies including a plurality of channels, and does not necessarily match the frequency band (band) defined in the standards such as IEEE802.11b, 11a, 11g, 11n, and 11ac. do not do.

  The control unit 21 of the second wireless device 20 is a program control device such as a CPU and operates according to a program stored in the storage unit 22. In the example of the present embodiment, the control unit 21 operates as a wireless repeater. The second wireless device 20 is communicatively connected to the first wireless device 10 functioning as a master device thereof, and also capable of communicating with the client device 30 which is a slave device to the second wireless device 20. Connected to.

  Then, the control unit 21 relays communication between the first wireless device 10 which is a master device for the second wireless device 20 and the client device 30 which is a slave device for the second wireless device 20. Perform processing.

  As a method for the control unit 21 to communicate with the first wireless device 10, a method of performing communication with the first wireless device 10 in the operation as an access point of the control unit 21 (access In addition to point-to-point communication (a method using a so-called WDS (Wireless Distribution System)), the control unit 21 functions as an access point and also as a client, and the function as a client allows communication with the first wireless device 10. (In this method, when the wireless LAN interface unit 23 described later includes a plurality of wireless LAN interface modules, each wireless LAN interface module corresponds to a function as an access point and a function as a client. May be used separately from the one corresponding to The wireless LAN interface module may be used in a time division manner), but in the present embodiment, it does not matter what method is used.

  The second wireless device 20 of the present embodiment may be communicably connected to another second wireless device 20. In this case, the second wireless device 20 on the side closer to the first wireless device 10 (upstream side) is the parent of the other second wireless device 20 on the side farther from the first wireless device 10 (downstream side). Functioning as a device, it relays communication between the first wireless device 10 or the second wireless device 20 on the upstream side and the second wireless device 20 on the downstream side. In this case, the second wireless device 20 on the upstream side operates as a master device for the second wireless device 20 on the downstream side.

  Like the control unit 11 of the first wireless device 10, the control unit 21 is a slave device (the client device 30 or the other second wireless device 20 that is wirelessly transmitted / received by the wireless LAN interface unit 23). ) Is stored in the storage unit 22 as the communication status information in association with the information specifying the frequency band used for communication with each (for example, the MAC address of each child device) (see FIG. 2). It will be similar to the one illustrated).

  Further, in the present embodiment, the control unit 21 of the second wireless device 20 includes the second wireless device 20 itself and the first wireless device 10 that is the parent device (corresponding to other wireless devices of the present invention. Is used as a target device, and information indicating the usage status of each frequency band in the target device is acquired, and congestion is calculated for each frequency band from the usage status of each frequency band represented by the acquired information. Predict. Then, the control unit 21 obtains prediction result information indicating the result of the prediction. In addition, the control unit 21 selects a frequency band used for communication between itself (the second wireless device 20 itself) and the first wireless device 10, which is the master device, based on the prediction result information, The wireless LAN interface unit 23 is controlled so as to communicate with the first wireless device 10 using a channel belonging to the selected frequency band. The details of the operation of the control unit 21 will be described later.

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

  The wireless LAN interface unit 23 includes at least one wireless LAN interface module 230a, 230b, ... (Hereinafter, when it is not necessary to distinguish between the wireless LAN interface modules 230a, 230b ,. Prepare The wireless LAN interface module 230 is connected to the client device 30 or another second wireless device 20 connected as a slave device of a communication partner, and to the first wireless device 10 connected as a master device. , Wirelessly communicates using any channel belonging to the designated frequency band, and outputs information received from these other wireless devices or slaves to the control unit 21. In addition, the wireless LAN interface module 230 sends the instructed information to another wireless device or a child device, which is a destination, using the channel according to the instruction input from the control unit 21. Further, in the present embodiment, the wireless LAN interface module 230 also belongs to any one of a plurality of frequency bands, like the wireless LAN interface module 140 of the wireless LAN interface unit 14 of the first wireless device 10. It is assumed that wireless communication is possible on any channel, and as an example, communication is performed using channels belonging to each frequency band of 2.4 GHz band and 5 GHz band. Further, the wireless LAN interface module 230, under the control of the control unit 21, sets a frequency band used for communication with the first wireless device 10, and any channel belonging to the set frequency band. Is used to communicate with the first wireless device 10. A widely known method may be used as a method of selecting a channel used for actual communication when a certain frequency band is determined.

  The client device 30 is various wireless LAN communication devices (slave devices) including, for example, a mobile terminal such as a smartphone, a video device such as a television, and an IP phone. The client device 30 has a client function in the wireless LAN standard, communicates with the first wireless device 10 or the second wireless device 20, and is the first wireless device as a communication partner. Data is transmitted / received to / from a web server, a SIP (Session Initiation Protocol) server, and other devices via the 10 or the second wireless device 20.

  Here, operations of the control unit 11 of the first wireless device 10 and the control unit 21 of the second wireless device 20 according to the present embodiment will be described. In the present embodiment, the control unit 11 of the first wireless device 10, which is the parent device, executes the program stored in the storage unit 12 to execute the communication status information request receiving unit 41 as illustrated in FIG. And the communication status information response unit 42 are functionally realized. In addition, the control unit 21 of the second wireless device 20 executes the program stored in the storage unit 22 so that the usage state acquisition unit 50, the congestion prediction unit 51, and the bandwidth as illustrated in FIG. The selection unit 52 and the wireless communication control unit 53 are functionally realized.

  Here, the communication status information request acceptance unit 41 accepts the request for communication status information from the second wireless device 20, and instructs the communication status information response unit 42 to respond. The communication status information response unit 42 generates response information relating to the communication status information stored in the storage unit 12, and sends the generated response information to the second wireless device 20 that is the requester of the communication status information. Send out.

  Specifically, the response information generated here may be the communication status information itself stored in the storage unit 12, or may be the following statistical information. That is, in the example of the present embodiment, the communication status information response unit 42 can use different frequency bands (regardless of whether they are currently used or not) based on the communication status information stored in the storage unit 12. For each frequency band), the number of slave units communicating using the frequency of the frequency band is counted. Then, as illustrated in FIG. 5, the communication status information response unit 42 communicates by using information B1, B2, ... Specifying each frequency band and the frequency of the frequency band specified by the information. Information representing the number of slave units N [Bi] (i = 1, 2, ...) Is generated as response information, and the generated response information is transmitted to the second wireless device 20 that is the request source of the communication status information. To send.

  The usage status acquisition unit 50 acquires the communication status information of the target device at a predetermined timing. Specifically, the target devices here are the first wireless device 10 (that is, the master device) and the self device itself (the second wireless device 20). The usage status acquisition unit 50 of the present embodiment sends a request for communication status information to the first wireless device 10, which is a master device.

  Here, the above-mentioned predetermined timing may be, for example, at the start of connection with the first wireless device 10 (master device) or at each predetermined time interval. Further, the timing at which the communication in which the communication amount exceeds the threshold is detected based on the communication amount (data amount per unit time) may be set as the predetermined timing.

  The usage status acquisition unit 50 receives the response information related to the communication status information from the first wireless device 10, which is the request destination of the communication status information, and stores it in the storage unit 22. The usage status acquisition unit 50 also reads the communication status information of the second wireless device 20 itself stored in the storage unit 22 and acquires information corresponding to the response information received from the first wireless device 10. To do.

  For example, if the response information received from the first wireless device 10 is the statistical information obtained based on the communication status information as illustrated in FIG. 5, the usage state acquisition unit 50 stores the storage unit 22. The same statistical information is generated based on the communication status information of the second wireless device 20 itself stored in. In this example, the usage status acquisition unit 50 specifically obtains, as this statistical information, for each frequency band different from each other, the number of slave units that are communicating using the frequency of the frequency band. And That is, the usage status acquisition unit 50 refers to the communication status information of the second wireless device 20 itself, which is stored in the storage unit 22, and performs communication by using the frequency of the frequency band for each different frequency band. To count the number of cordless handsets. Then, the usage status acquisition unit 50 communicates with each other by using the information B1, B2, ... Specifying each frequency band and the frequency of the frequency band specified by the information similar to the one illustrated in FIG. Information representing the number of slave units Nr [Bi] (i = 1, 2, ...) Is generated.

  The congestion prediction unit 51 uses the information related to the communication status information of the first wireless device 10, which is the master unit, and the information related to the communication status information of its own obtained as described above, and the usage status for each of the different frequency bands. Predict (communication volume, etc. for each frequency band). As an example, this usage prediction is based on the number of handsets using the frequency of each frequency band, assuming that each handset performs the same amount of communication per unit time. The usage status for each frequency band may be numerically predicted. In this example, the congestion prediction unit 51 indicates the number of slave units that are communicating with the first wireless device 10 at a frequency in the frequency band represented by certain information Bi (i = 1, 2, ...). N [Bi] is added to the number Nr [Bi] of slave units that are communicating with the second wireless device 20 at the frequency of the frequency band represented by the information Bi, and the information Bi is added. E [Bi] = N [Bi] + Nr [Bi] is set as the prediction result information indicating the congestion prediction result for each frequency band. This value corresponds to the result of congestion prediction for each frequency band.

  The band selection unit 52 selects a frequency band used for communication between the first wireless device 10 and the second wireless device 20 based on the congestion prediction result information for each frequency band generated by the congestion prediction unit 51. To do. As a specific example, in the example of the present embodiment, the band selection unit 52 refers to the prediction of congestion for each frequency band obtained as the prediction result information, and the value of the predicted communication traffic E [Bi] is the smallest. Information (Bmin) for specifying the frequency band is output to the wireless communication control unit 53.

  The wireless communication control unit 53 uses the wireless LAN of the wireless LAN interface unit 23 so as to communicate with the first wireless device 10 on the channel belonging to the frequency band specified by the information output by the band selection unit 52. It controls the interface module 230. Specifically, the wireless communication control unit 53 refers to the communication status information stored in the storage unit 22, and the wireless LAN interface module in which the second wireless device 20 is currently communicating with the first wireless device 10. If there is a wireless LAN interface module 230 that is communicating with the first wireless device 10, the wireless LAN interface module 230 is currently connected to the first wireless device 10. Information Bp representing the frequency band used in the communication between them is acquired. Then, the wireless communication control unit 53 checks whether or not the information Bp acquired here is the same as Bmin, and if the information Bp is the same, continues the communication with the first wireless device 10 (do nothing). ).

  On the other hand, if the information Bp acquired here is not the same as Bmin, the wireless communication control unit 53 uses the wireless LAN interface module 230 that is communicating with the first wireless device 10. Instruct to switch the frequency band. Then, the frequency band used by the wireless LAN interface module 230 is switched, and the communication with the first wireless device 10 is continued on the channel belonging to the frequency band after switching. Since a widely known method can be adopted as the switching method, detailed description thereof is omitted here.

[motion]
The wireless LAN communication system of the present embodiment has the above configuration and operates as follows. In the following example, the first wireless device 10 communicates with the client devices 30a and 30b and the second wireless device 20 on a channel belonging to the 2.4 GHz band, and with the client device 30c. It is assumed that communication is performed on a channel that belongs to the 5 GHz band. The second wireless device 20 communicates with the client device 30d and the first wireless device 10 on a channel belonging to the 2.4 GHz band, but does not communicate with the 5 GHz band (in the 5 GHz band, Communication is possible, but there is no communication partner).

  The second wireless device 20 starts the process illustrated in FIG. 6 at a predetermined timing and requests the first wireless device 10 for communication status information (S1). In response to this request, the first wireless device 10 sends response information indicating that communication is being performed with three slave units in the 2.4 GHz band and one slave unit in the 5 GHz band (S2).

  The second wireless device 20 also generates, as its own communication status information, information indicating that it is communicating with one slave in the 2.4 GHz band and zero slaves in the 5 GHz band (S3). Then, the second wireless device 20 has the number of slave units with which the first wireless device 10 and itself (the second wireless device 20) are communicating in each frequency band, that is, in each of the 2.4 GHz band and the 5 GHz band. Is calculated as congestion prediction result information (S4). Here, the prediction result information is 3 + 1 = 4 for the 2.4 GHz band and 1 + 0 = 1 for the 5 GHz band.

  The second wireless device 20 refers to this prediction result information and selects the frequency band in which the value indicating the prediction of congestion is the minimum as the candidate frequency band (S5). Here, the value indicating the usage status of the 5 GHz band (“1” in the above example) is smaller than the value indicating the usage status of the 2.4 GHz band (“5” in the above example), and it is the smallest. The second wireless device 20 selects the 5 GHz band as a candidate frequency band. The second wireless device 20 currently determines whether or not communication is being performed with the first wireless device 10 on the channel belonging to the 5 GHz band selected here (S6). In this example, since the first wireless device 10 and the second wireless device 20 are communicating in the 2.4 GHz band (No in S6), the second wireless device 20 is the first wireless device. The frequency band used for communication with the wireless device 10 is switched to the candidate frequency band of 5 GHz band (S7: switching of frequency band). As a result, the second wireless device 20 and the first wireless device 10 communicate with each other on the channel belonging to the frequency band of 5 GHz band.

  On the other hand, if it is determined in process S6 that communication is being performed with the first wireless device 10 in the frequency band selected in process S5 (Yes in S6), the second wireless device 10 is used. The device 20 ends the process without changing the frequency band.

  In addition, here, the second wireless device 20 sets both the first wireless device 10 and itself (the second wireless device 20) as target devices, and refers to both of the communication status information in the target devices, Although the congestion is predicted, the present embodiment is not limited to this. For example, the second wireless device 20 may target only the first wireless device 10 as a target device and predict congestion from the information on the communication status of the target device. In this case, in the process S4, the information itself received from the first wireless device 10 is used as the prediction result information. Further, in this case, the execution of the process S3 is not always necessary.

  Also, the second wireless device 20 may target itself as the target device and predict congestion based only on the information on the communication status of itself. In this case, in the process S4, the information itself generated in the process S3 is used as the prediction result information. Further, in this case, the processes S1 and S2 are not necessarily required to be executed, and the first wireless device 10 does not have to respond to the request for the communication status information.

[Modification]
Further, in the present embodiment, the value indicating the congestion for each frequency band of the target device is not limited to the value based on the number of slave devices connected to the target device. For example, in the present embodiment, the congestion prediction is at least one of the type of slave unit connected to the target device and the content of communication between the target device and the slave unit connected to the target device for each frequency band. Information may be used.

  That is, in the example of the present embodiment, the control unit 21 of the second wireless device 20 uses the frequency of each frequency band, which is obtained for each frequency band, as the usage information, and is a predetermined type of slave device. Whether or not (or the number of child devices of a predetermined type) may be obtained. Here, the predetermined type is, for example, a type of a predetermined device such as a media device having a relatively large amount of communication (the client device 30 transmitting and receiving video information or audio information).

  In this example, the control unit 11 or the control unit 21 of the first wireless device 10 or the second wireless device 20 is, for each frequency band, a client that is a media device that transmits and receives information using the frequency of the frequency band. It is assumed that the number of devices 30 is counted and stored as communication status information in the storage unit 12 or the storage unit 22.

The control unit 11 or the control unit 21 determines whether or not the communication partner is a media device as in the following example. That is, if the communication partner is a media device,
(1) There is a request to browse the video information (2) The action (Browse command) in UPnP to acquire the directory is sent out (3) The device class information in UPnP includes information indicating that it is a media device One of the above conditions is satisfied. Therefore, the control unit 11 or the control unit 21 monitors whether or not the information corresponding to the above items (1) to (3) is included in the information transmitted by the communication partner, which is a slave device, and When such information is detected, it is determined that the slave device that is the partner of the communication is a media device, and the frequency band used in communication with the partner of the communication that is determined to be the media device is specified. Information to be associated with the other party (which may be the other party's MAC address or the like) is stored in the storage unit 12 or 22 as communication status information.

  In this example, when the control unit 21 of the second wireless device 20 makes a request for communication status information to the first wireless device 10, the first wireless device 10 responds to this request in the 2.4 GHz band and Information indicating the number of media devices detected in each of the 5 GHz bands is transmitted as response information.

  Further, the control unit 21 of the second wireless device 20 has information indicating the number of media devices detected in each of the 2.4 GHz band and the 5 GHz band as its communication status information, and the response information sent by the first wireless device 10. And the information contained in, the total number of slave units that are media devices with which the first wireless device 10 and itself (the second wireless device 20) are communicating in the 2.4 GHz band and the 5 GHz band, respectively. Is calculated as congestion prediction result information. Here, with respect to the frequency band to which the frequency of wireless communication used for transmitting and receiving video information or audio information belongs, the value indicating congestion in the prediction result information is a value other than "0". That is, this prediction result information corresponds to the information that specifies the frequency band to which the frequency of the wireless communication used for transmitting and receiving the video information or audio information belongs in the present invention.

  The control unit 21 of the second wireless device 20 refers to this prediction result information and finds a frequency band (candidate frequency band) in which the value indicating congestion is “0” (or the minimum). It is determined whether or not communication is being performed with the first wireless device 10 in the issued candidate frequency band. Then, in the communication between the second wireless device 20 and the first wireless device 10, if the channel belonging to the candidate frequency band is used, the communication is continued as it is. Further, in communication between the second wireless device 20 and the first wireless device 10, if the channel belonging to the candidate frequency band is not used, the frequency band to be used is switched to the candidate frequency band, and after switching. The communication with the first wireless device 10 is performed on the channel belonging to the frequency band of.

  Also in this example, here, the second wireless device 20 sets both the first wireless device 10 and itself (the second wireless device 20) as the target devices, and information on the communication status of the target devices ( Among the communication partners, the number of slave units determined as media devices) is referred to for predicting the congestion for each frequency band, but the first wireless device 10 or the second wireless device 20 does not have to be congested. The frequency band used for communication with the first wireless device 10 may be controlled based on the number of media devices with which either one is communicating.

  Further, in the examples so far, the media device is not limited to the video device, and may be an audio device (for example, an IP telephone). The control unit 11 of the first wireless device 10 and the control unit 21 of the second wireless device 20 determine whether or not the communication partner is an IP telephone, for example, whether or not communication is performed by the SIP protocol. It may be judged by. In addition, the first wireless device 10 and the second wireless device 20, which are target devices, may predict congestion by using the content of communication with the connected slave device. Specifically, the control unit 11 of the first wireless device 10 and the control unit 21 of the second wireless device 20 perform communication using RTP (Real-time Transport Protocol) and RTCP (Real-time Transport Control Protocol). The client device 30 transmitting / receiving the video information or the audio information may be determined as the media device and the above process may be performed.

  According to this example of the present embodiment, the first wireless device 10 and the second wireless device 20 avoid the channel in the frequency band used by the media device that is considered to have a relatively large amount of communication. Since communication is performed, the utilization efficiency of the frequency band can be improved.

[Example of processing between relay devices]
In addition, although the example in which the first wireless device 10 is used as the master device has been described in this example, the present embodiment is not limited to this, and the second wireless device 20 has the first wireless device 10 rather than itself. When connected to another second wireless device 20 on the side close to (the upstream side of communication), the other second wireless device 20 is used as a master device and the master device and self are used as target devices. You may perform the said process. In this case, the control unit 21 of the second wireless device 20 that functions as a master device with respect to the other second wireless device 20 also operates as the communication status information request accepting unit 41 and the communication status information responding unit 42. Will be done. In this example, even when the second wireless device 20 is configured in multiple stages, the frequency band used for communication between the second wireless devices 20 can be set according to the usage status of each frequency band.

[Example of using communication status information]
Further, in the above description, the usage status is predicted by the communication status between the parent device such as the first wireless device 10 and the second wireless device 20 itself as the target device (the number of connected slave devices for each frequency band, etc.). However, in the present embodiment, the control unit 21 of the second wireless device 20 further includes the signal strength (RSSI) used for communication with the parent device and the child device. , The signal / noise ratio (SNR), the packet error rate, and other information relating to communication quality may be used to obtain the prediction result information.

Specifically, in this example, the control unit 21 of the second wireless device 20 communicates the prediction result information U [Bi] for each frequency band B1, B2, ... With a channel belonging to the frequency band. The number of slaves E [Bi] (the number of slaves N [Bi] with which the access point device 20 or the like that functions as a master for the second wireless device 20 is communicating, The number of slave units Nr [Bi] or the sum thereof) and the signal strength RSSI,
U [Bi] = E [Bi] + α / RSSI
May be calculated as Here, α is a positive constant that is experimentally determined.

  Then, the control unit 21 searches for the frequency band Bmin in which the value U [Bi] of the usage status is the minimum, and controls the channel belonging to the frequency band Bmin to communicate with the master unit.

According to this example, the lower the RSSI, the larger the value of the usage status is corrected, and thus the possibility that a channel belonging to a frequency band having a low RSSI is used for communication with the master device is reduced. When the packet error rate (PER) is used, the prediction result information is
U [Bi] = E [Bi] + β · PER
As described above (where β is a positive constant that is experimentally determined as appropriate), the larger the value, the larger the value of the usage condition is corrected. This reduces the possibility that a channel belonging to a frequency band with a relatively high packet error rate will be used for communication with the parent device.

[Consideration of cordless handsets using multiple channels]
Furthermore, the communication status information generated by the control unit 11 or the control unit 21 of the first wireless device 10 or the second wireless device 20 is, for each frequency band, a client that transmits and receives information using the frequency of the frequency band. The number is not limited to the number of devices 30 or the number of client devices 30 that are media devices. For example, the number of client devices 30 that occupy a plurality of channels and perform communication may be counted.

[Other aspects]
Further, in the above example, the second wireless device 20 connected to the master device such as the first wireless device 10 selects the frequency band used for communication with the master device. However, the control unit of the base unit performs the same operation as that of the control unit 21 of the second wireless device 20 described above, and is used for communication with the second wireless device 20. The frequency band may be controlled. In this case, the master device needs to identify the second wireless device 20 from the connected slave devices. This identification is predetermined identification information in the packet transmitted by the second wireless device 20. In addition, it can be performed by detecting the identification information in the parent device.

10 access point device, 11 control unit, 12 storage unit, 13 wired LAN interface unit, 14 wireless LAN interface unit, 20 relay device, 21 control unit, 22 storage unit, 23 wireless LAN interface unit, 30 client device, 41 communication status Information request accepting unit, 42 communication status information responding unit, 50 use state information acquiring unit, 51 congestion predicting unit, 52 band selecting unit, 53 wireless communication control unit.

Claims (6)

While communicating with another wireless device that functions as a master unit using any one of a plurality of frequency bands, wirelessly communicates with a slave unit, and the master unit and the slave unit. A wireless device that relays communication with
A means for acquiring information indicating a usage state for each frequency band in at least one of the wireless device itself or the master unit;
From the use state for each frequency band represented by the acquired information, means for predicting congestion of the frequency band to obtain prediction result information,
Means for selecting a frequency band used for communication with the master unit based on the prediction result information,
Means for communicating with the base unit using the selected frequency band,
Wireless device equipped with. The wireless device according to claim 1, wherein
Means for obtaining information indicating the usage status for each frequency band, the target device is at least one of the wireless device itself or the master unit,
The number of slave units connected to the target device for each frequency band of the target device,
The type of the slave unit connected to the target device,
A wireless device that obtains, as information indicating the usage state, information regarding at least one of the content of communication between the target device and the slave connected to the target device. The wireless device according to claim 1 or 2, wherein
If the wireless device itself or at least one of the other wireless devices is transmitting / receiving video information or audio information to / from the child device, it is used to transmit / receive the video information or audio information. Outputs information that identifies the frequency band,
A wireless device in which the means for selecting a frequency band selects a frequency band different from the frequency band specified by the output information. The wireless device according to any one of claims 1 to 3,
A wireless device that selects a frequency band based on the prediction result information at a predetermined timing. The wireless device according to claim 4,
The predetermined timing is
Timing to connect with the base unit,
Timing at regular intervals,
The timing when the communication volume (data volume per unit time) exceeds the threshold,
A wireless device including at least one of the following. A first wireless device and a second wireless device that can communicate with each other using any one of the plurality of frequency bands are provided, and the first wireless device and the second wireless device respectively include the plurality of the plurality of frequency bands. A wireless communication system in which communication is performed with a child device using any of frequency bands, and the second wireless device relays communication between the first wireless device and the child device,
The second wireless device is
Means for acquiring information indicating a usage state for each frequency band in at least one of the first wireless device and the second wireless device;
From the use state for each frequency band represented by the acquired information, means for predicting congestion of the frequency band to obtain prediction result information,
A means for selecting a frequency band used for communication between the first wireless device and the second wireless device based on the prediction result information,
A wireless communication system in which the first wireless device and the second wireless device communicate with each other using the selected frequency band.

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