Communication device, wireless communication system, and program

Abstract

To provide a communication device capable of performing stable communications by preventing much time from being required for retrieving an access point of a high radio field intensity, a radio communication system, and a program.SOLUTION: Channel information including identification information for identification from the other communication device and information relating to a channel of radio communications with the other communication device, to which an own device is connected at present, is transmitted to a server and a connection history including a radio wave intensity for each other communication device to which the own device is connected is stored. The channel information including information of the other communication device is received from the server. In a case where the channel of the radio communications with the other communication device to which the own device is connected at present is a channel of a predetermined frequency band and there is a communication device of a stronger radio wave intensity than the radio wave intensity of the other communication device to which the own device is connected in present in the connection history, a connection destination is retrieved within a range of channels described in channel information of the communication device of the stronger radio wave intensity and the channel of the radio communications with the communication device to which the own device is connected at present.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a communication device, a wireless communication system, and a program. [Background technology]

[0002] The order management systems used in restaurants consist of an input terminal that inputs order information and communicates wirelessly, a communication device with an access point function that connects the order terminal device to a network, a wireless relay device that relays wireless signals, multiple output devices (printers and display devices), and an order management device that controls these.

[0003] Here, the wireless relay device and the input terminal select and connect to an access point with high radio wave intensity. On the other hand, in recent years, radio wave interference has become a frequent problem, and a DFS (Dynamic Frequency Selection) function has been adopted as an access point function to avoid radio wave interference (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 049468 Summary of the Invention [Problem to be solved by the invention]

[0005] When a wireless relay device or input terminal is connected to an access point, it searches for an access point with stronger radio wave strength than the currently connected access point, so when searching for an access point on a channel different from the current channel, it is necessary to switch to another channel. In particular, when there are many candidate channels to switch to, the search takes time, and if communication is in progress, the communication time increases and the connection to the access point may be disconnected. Another problem is that when the channel is changed using the DFS function, a certain waiting time occurs.

[0006] Therefore, the present invention has been made in consideration of the above points, and aims to provide a communication device, a wireless communication system, and a program that can prevent the time required for searching for access points with high radio wave strength and enable stable communication. [Means for solving the problem]

[0007] A first aspect of the communication device includes a transmitting unit that transmits to a server channel information including identification information that identifies the communication device having an access point function from other communication devices that also have an access point function and information regarding the channel of wireless communication with the other communication devices to which the communication device is currently connected; a memory unit that stores a connection history including the radio wave strength for each of the other communication devices to which the communication device has connected; a receiving unit that receives the channel information including the information of the other communication devices from the server; and, if the channel of wireless communication with the other communication devices to which the communication device has currently connected is a channel of a predetermined frequency band and the connection history includes a communication device with a radio wave strength stronger than that of the other communication device to which the communication device is currently connected, a searching unit that searches for a connection destination within a range between the channel listed in the channel information of the communication device with the stronger radio wave strength and the channel of wireless communication with the communication device to which the communication device is currently connected.

[0008] According to the communication device of the first aspect, it is possible to provide a communication device that can prevent a search for an access point with high radio wave intensity from taking a long time and that can perform stable communication.

[0009] In addition, in the communication device of the second aspect, the predetermined frequency band is a DFS (Dynamic Frequency Selection) frequency band.

[0010] According to the second aspect of the communication device, even when the channel is changed by DFS, it is possible to provide a communication device that can prevent the time required for searching for an access point with high radio wave strength and can perform stable communication.

[0011] In addition, in a communication device of a third aspect, the search unit executes the search when the radio wave strength is stronger than a value obtained by adding a predetermined value to the radio wave strength of the other communication device to which the communication device is currently connected.

[0012] According to the communication device of the third aspect, it is possible to reduce the number of processes for switching access points, and to prevent communication from becoming unstable due to unnecessary switching of access points.

[0013] Further, a wireless communication system of a fourth aspect includes a communication device, a plurality of other communication devices connected to the communication device, and a server to which the communication device and the other communication devices are connected, and the communication device includes a transmitting unit that transmits channel information to the server, the channel information including identification information that identifies the communication device having an access point function from the other communication devices having an access point function and information regarding the channel of wireless communication with the other communication devices to which the communication device is currently connected, a memory unit that stores a connection history including the radio wave strength of each of the other communication devices to which the communication device has connected, a receiving unit that receives the channel information including the information of the other communication devices from the server, and, if the connection history includes a communication device with a radio wave strength stronger than the radio wave strength of the other communication device to which the communication device is currently connected, a searching unit that searches for a connection destination within the range of the channel listed in the channel information of the communication device with the stronger radio wave strength and the channel of wireless communication with the communication device to which the communication device is currently connected.

[0014] According to the wireless communication system of the fourth aspect, it is possible to provide a wireless communication system that can prevent a search for an access point with high radio wave intensity from taking a long time and that can perform stable communication.

[0015] In addition, a fifth aspect of the program causes a computer to transmit to a server channel information including identification information that identifies the own device having an access point function from other communication devices that also have an access point function and information regarding the channel of wireless communication with the other communication device to which the own device is currently connected, store a connection history including the radio wave strength for each of the other communication devices to which the own device is connected, receive the channel information including the information on the other communication devices from the server, and, if the connection history includes a communication device with a radio wave strength stronger than the radio wave strength of the other communication device to which the computer is currently connected, execute a process of searching for a connection destination within a range between the channel listed in the channel information of the communication device with the stronger radio wave strength and the channel of wireless communication with the currently connected communication device.

[0016] According to the program of the fifth aspect, it is possible to provide a program that can prevent a search for an access point with high radio wave intensity from taking too much time and enables stable communication. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a communication device that can prevent the time required for searching for an access point with high radio wave intensity and that can perform stable communication. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic configuration diagram of an order management system according to an embodiment of the present invention. [Figure 2] 1 is a schematic block diagram of a wired device according to an embodiment of the present invention; [Figure 3] 1 is a schematic block diagram of a wireless relay device according to an embodiment of the present invention; [Figure 4]3 is an explanatory diagram illustrating an example of a channel information file according to an embodiment of the present invention; FIG. [Figure 5] FIG. 4 is an explanatory diagram illustrating an example of a connection history according to an embodiment of the present invention. [Figure 6] FIG. 2 is an explanatory diagram illustrating an example of a Beacon list according to an embodiment of the present invention. [Figure 7] FIG. 10 is an explanatory diagram illustrating a state when a channel is changed by a DFS according to an embodiment of the present invention. [Figure 8] 10 is a flowchart showing an example of a process for connecting to an access point according to an embodiment of the present invention. [Figure 9] 9 is a flowchart showing an example of step S105 in FIG. 8. [Figure 10] 9 is a flowchart showing an example of step S107 in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0019] An example of an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals are used throughout the drawings to designate identical or equivalent components and parts. The dimensional proportions of the drawings are exaggerated for illustrative purposes and may differ from the actual proportions.

[0020] An example of an order management system 1 according to the present embodiment will be described with reference to Fig. 1. The order management system 1 is an example of a wireless communication system. FIG. 1 is a diagram showing an example of a schematic configuration of an order management system 1 according to the present embodiment. 1, an order management system 1 according to this embodiment is housed in a store such as a restaurant. The order management system 1 includes a controller 10, communication devices 20A, 20B, 30A, 30B, and 30C, an input terminal 40, an accounting device 50, and a router 60.

[0021] In this embodiment, the controller 10 has a server function that manages the entire order management system 1. The controller 10 can communicate with the communication devices 20A and 20B, the checkout device 50, and the router 60 via a wired network N1. The controller 10 can communicate with the communication devices 30A, 30B, and 30C and the input terminal 40 via a wireless network N2. The wired network N1 may be, for example, a local area network (LAN) established in a store via wired connections. The wireless network N2 may be Wi-Fi (registered trademark), an example of a wireless LAN standard. That is, the controller 10 also has a wireless communication function as an access point for the wireless network N2. The access point function of the controller 10 will be described later, along with the access point function of the communication devices 20A, 20B, 30A, and 30B. In this embodiment, the controller 10 with the access point function is also referred to as an access point.

[0022] Here, a case where Wi-Fi (registered trademark) is used as an example of the wireless network N2 will be described. Wi-Fi (registered trademark) uses channels (CH) that use a predetermined frequency band, for example, W53 (5260 MHz to 5320 MHz) for channels 52, 56, 60, and 64, and W56 (5500 MHz to 5720 MHz) for channels 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, and 144. The frequency bands of the W53 and W56 channels may be subject to interference with radar waves from weather radar, aircraft radar, and the like. For this reason, a DFS function is provided that disables the use of channels in that frequency band for a predetermined period of time when radar waves are detected.

[0023] Furthermore, the controller 10 according to this embodiment has the function of storing channel information files (see FIG. 4) transmitted from the communication devices 20A, 20B, 30A, and 30C, and transmitting the same to the communication devices 20A, 20B, 30A, 30B, and 30C, as will be described later.

[0024] In this embodiment, communication devices 20A, 20B, 30A, 30B, and 30C are capable of communicating with input terminals 40, such as handheld terminals used by customers at their tables, tablet terminals used by customers, and smartphones owned by customers, via a wireless network N2. That is, communication devices 20A, 20B, 30A, and 30B have wireless communication capabilities as access points to the wireless network N2. In this embodiment, communication devices 20A, 20B, 30A, and 30B with access point capabilities are also referred to as access points. Communication devices 20A, 20B, 30A, 30B, and 30C are each composed of wired devices 20A and 20B connected to a wired network N1 and wireless relay devices 30A and 30B (so-called repeaters) that are wirelessly connected to wired devices 20A and 20B and relay the connection of input terminals 40 to the wired network N1. The wireless relay devices 30A and 30B are devices that mainly relay between the wired devices 20A and 20B and an input terminal 40 used in a location in a store where wireless radio waves from the access points of the wired devices 20A and 20B are difficult to reach, and transmit order data from the input terminal 40 to the wired devices 20A and 20B. It should be noted that not all of the communication devices 20A, 20B, 30A, and 30B are necessarily provided with wireless communication functions as access points. In the example shown in FIG. 1 , the communication device 30C does not have wireless communication functions as an access point. Furthermore, when it is not necessary to distinguish between the wired devices 20A and 20B, the wired devices 20A and 20B are collectively referred to as the wired device 20, and when it is not necessary to distinguish between the wireless relay devices 30A and 30B, the wireless relay devices 30A and 30B are collectively referred to as the wireless relay device 30.

[0025] The input terminal 40 in this embodiment is a device for inputting order data, such as a handheld terminal used by a customer service representative for work, a tablet terminal used by a customer at each table, or a smartphone personally owned by a customer.

[0026] The accounting device 50 in this embodiment is connected to a wired network N1, and as an example, a POS (Point Of Sales) register or the like is applied.

[0027] The router 60 in this embodiment is a device for connecting the wired network N1 and an external network N3. The external network N3 may be, for example, the Internet, a Wide Area Network (WAN), or a Virtual Private Network (VPN).

[0028] For example, communication devices 20A, 20B, 30A, and 30B transmit order data indicating orders from customers received from input terminal 40 via wireless network N2 to controller 10. Controller 10 stores and manages the received order data for each customer. Based on the received order data, controller 10 generates slip data for printing a slip and transmits the generated slip data to a printer (not shown) to output the slip. Furthermore, accounting device 50 performs accounting for each customer based on the slip printed by the printer, and transmits information indicating the completion of accounting to controller 10. Note that some of communication devices 20A, 20B, 30A, 30B, and 30C may be equipped with a printer function.

[0029] Furthermore, although not shown, the controller 10 and communication devices 20A, 20B, 30A, and 30B having an access point function periodically transmit Beacons, for example, every 15 seconds, to connect with the wireless relay device 30 and input terminal 40 that serve as clients. Such Beacons include radio wave strength as shown in Fig. 6, and the wireless relay device 30 stores past radio wave strengths as well as other information as a Beacon list.

[0030] (Communication device 20A, 20B, 30A, 30B, 30C) Next, the hardware configuration of communication devices 20A, 20B, 30A, 30B, and 30C according to this embodiment will be described. Since the wireless relay device 30 has the same basic configuration as the wired device 20, the wired device 20 will be described as a representative. Note that the wireless relay device 30 does not include a radar detection unit 108, which will be described later.

[0031] FIG. 2 is a block diagram of wired device 20 according to this embodiment. 2, the wired device 20 according to this embodiment includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a storage 104, an input unit 105, a display unit 106, a communication interface (I / F) 107, and a radar detection unit 108. Each component is connected to each other via a bus 109 so as to be able to communicate with each other.

[0032] The CPU 101 is a central processing unit that executes various programs and controls each part. That is, the CPU 101 reads programs from the ROM 102 or the storage 104 and executes the programs using the RAM 103 as a work area. The CPU 101 controls the above-mentioned components and performs various arithmetic processing in accordance with the programs recorded in the ROM 102 or the storage 104.

[0033] The ROM 102 stores various programs and various data. The RAM 103 temporarily stores programs or data as a working area. The storage 104 is configured with a storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory, and stores various programs including an operating system and various data. The storage 104 is also an example of a storage unit.

[0034] The input unit 105 includes a pointing device such as a mouse and a keyboard, and is used to input various types of information.

[0035] The display unit 106 is, for example, a liquid crystal display, and displays various information under the control of the CPU 101. The display unit 106 may also function as the input unit 105 by employing a touch panel system.

[0036] The communication interface 107 is an interface for communicating with other devices in the store, and for example, in the case of the wired device 20, a standard such as Ethernet (registered trademark) is used, and in the case of the wireless relay device 30, a standard such as Wi-Fi (registered trademark) is used.

[0037] Here, the programs stored in ROM 102 or storage 104 may be pre-installed in communication devices 20A, 20B, 30A, 30B, and 30C. Alternatively, the programs may be stored in a non-volatile storage medium or distributed via a network and installed appropriately in communication devices 20A, 20B, 30A, 30B, and 30C. Examples of non-volatile storage media include CD-ROMs (Compact Disk Read Only Memory), DVD-ROMs (Digital Versatile Disk Read Only Memory), USB (Universal Serial Bus) memories, memory cards such as SD (registered trademark) cards, and the like.

[0038] The radar detection unit 108 detects radar waves for the DFS function. When such radar waves are detected, the CPU 101 stops the channel currently being used and changes the channel to be used for wireless communication.

[0039] Additionally, if the communication devices 20A, 20B, 30A, 30B, and 30C have a printer function, they are provided with a printing unit.

[0040] When executing the above programs, the communication devices 20A, 20B, 30A, 30B, and 30C realize various functions using the above hardware resources. Here, the functional configuration realized by the wireless relay device 30 among the communication devices 20A, 20B, 30A, 30B, and 30C will be described.

[0041] FIG. 3 is a block diagram showing an example of the functional configuration of the CPU 101 of the wireless relay device 30. As shown in FIG.

[0042] 3, the wireless relay device 30 has, as its functional components, a transmitting unit 110, a receiving unit 120, and a searching unit 130. Each functional component is realized by the CPU 101 reading and executing a program stored in the ROM 102 or the storage 104.

[0043] (Transmitter 110) The transmitter 110 transmits to the controller 10 channel information including identification information that distinguishes the device having the access point function from the other communication devices 20A, 20B, 30A, and 30B that also have the access point function, and information regarding the channel of the other communication devices 20A, 20B, 30A, and 30B to which the device is currently connected. The timing at which the transmitting unit transmits the channel information is when each of the communication devices 20A, 20B, 30A, and 30B is started up or when the channel is changed, but is not limited to this and the information may be transmitted periodically. The transmitted channel information is stored by the CPU 101 of the controller 10 as a channel information file (see FIG. 4).

[0044] (Receiving unit 120) The receiving unit 120 receives channel information including information on the other communication devices 20A, 20B, 30A, and 30B from the controller 10. That is, the receiving unit 120 receives a channel information file from the controller 10.

[0045] (Search unit 130) When the channel for wireless communication with other communication devices 20A, 20B, 30A, and 30B to which the device itself is currently connected is a channel in a predetermined frequency band and the connection history (see FIG. 5) includes communication devices 20A, 20B, 30A, and 30B with stronger radio wave intensity than the radio wave intensity of other communication devices 20A, 20B, 30A, and 30B to which the device itself is currently connected, the search unit 130 searches (scans) for a destination access point within a range between the channel described in the channel information of the communication devices 20A, 20B, 30A, and 30B with stronger radio wave intensity and the channel of the currently connected communication devices 20A, 20B, 30A, and 30B. Here, the predetermined frequency band is a frequency band for DFS (Dynamic Frequency Selection). Furthermore, the search unit 130 executes a search (scan) triggered by DFS when the radio wave strength is stronger than the radio wave strength of the other currently connected communication devices 20A, 20B, 30A, 30B plus a predetermined value, for example, 30 dBm. In this way, by not changing the connection destination when the radio wave strength of the currently connected destination is high, it is possible to reduce the process of switching access points and prevent communication from becoming unstable due to unnecessary switching of access points.

[0046] Furthermore, the search unit 130 is not limited to searching (scanning) for access points to connect to within the range between the channels described in the channel information of the communication devices 20A, 20B, 30A, and 30B with strong radio wave strength and the channels of the currently connected communication devices 20A, 20B, 30A, and 30B, but is also capable of searching (scanning) all channels.

[0047] Next, an example of a channel information file in this embodiment will be described with reference to FIG.

[0048] FIG. 4 shows an example of a channel information file stored in the controller 10. When each communication device 20A, 20B, 30A, or 30B having an access point function communicates with the controller 10, the communication device transmits channel information to the controller 10, including identification information that identifies the communication device itself from the other communication devices 20A, 20B, 30A, or 30B having an access point function, and information regarding the wireless communication channel to which the communication device is currently connected with the other communication devices 20A, 20B, 30A, or 30B. Upon receiving this information, the controller 10 stores the channel information as a channel information file, along with information regarding the time of storage (timestamp). Examples of information stored in the channel information file include a "device name," a "serial number," a "MAC address," and a "channel." The information is not limited to these, and other information may be stored in the channel information file. Alternatively, only some information may be stored in the channel information file. Furthermore, the "model name" and "serial number" may be any information that can distinguish the device, such as an ID number assigned to each model. 4(A) is an example of a channel information file before the controller 10 (EST01) changes the channel due to DFS, as will be described later. Also, FIG. 4(B) is an example of a channel information file when the channel of the controller 10 (EST01) changes from 100CH shown in FIG. 4(A) to 104CH due to DFS.

[0049] Of the devices shown in FIG. 1, EST01 corresponds to the controller 10, EST02 corresponds to the communication device 20B, EPR03 corresponds to the communication device 20A, RPR04 corresponds to the communication device 30A, and RST03 corresponds to the communication device 30B.

[0050] In this example, as shown in FIG. 4(A), before the channel is changed by DFS, the controller 10 (EST01), communication device 20A (EPR03), and communication device 30A (RPR04) installed on the left side of FIG. 1 are connected on 100CH, while the communication device 20B (EST02) and communication device 30B (RST01) installed on the right side are connected on 104CH. Note that the communication device 30C (RPR05) in FIG. 1 does not have an access point function and is therefore not included in the channel information file. Furthermore, as shown in FIG. 4(B), the channel of the controller 10 (EST01) has changed from 100CH shown in FIG. 4(A) to 104CH by DFS.

[0051] The case where the controller 10 (EST01) is changed from 100CH to 104CH by DFS will be described later with reference to FIG.

[0052] Next, an example of the connection history in this embodiment will be described with reference to FIG.

[0053] 5 shows an example of a connection history stored in the storage 104 by the wireless relay device 30, particularly RPR04 (communication device 30A). The wireless relay device 30 stores history information about other communication devices to which it has connected in the past. Information stored as the connection history includes history information including the radio wave strength of each other communication device to which its own device (RPR04) has connected, such as "time," "device name," and "radio wave strength." In this example, it is stored that EST01 has a stronger radio wave strength than EPR03, and that EPR03 has a weaker radio wave strength than EST01.

[0054] Next, an example of a Beacon list in this embodiment will be described with reference to FIG.

[0055] FIG. 6 shows an example of a beacon list stored in the storage 104 of the wireless relay device 30, particularly RPR04. The beacon list stores beacons received at predetermined intervals, for example, every 100 msec, to check whether an optimal connection destination is available on the current channel (CH). As shown in FIG. 6, the beacon list stores the names of devices connectable on the current 100CH, the channel for each device name, the average radio wave strength, and past radio wave strength. Here, the past radio wave strength is stored as the radio wave strength included in beacons received, for example, every 15 seconds. Note that the radio wave strength included in all received beacons may also be stored. In the beacon list shown in FIG. 6, it can be seen that EST01 has stronger radio wave strength than EPR03. Note that if EST01 is changed from 100CH to another 104CH by DFS, it will disappear from the beacon list of RPR04, which is connected on 100CH.

[0056] Next, a state in which EST01 on 100CH in this embodiment is changed to another channel, for example, 104CH, by DFS will be described with reference to FIG. As shown in Figure 7(A), EST01 and EPR03 are access points using 100CH, and RPR04 is connected to EST01 on that 100CH. Then, EST01 is unable to use 100CH due to DFS, and changes to 104CH as shown in Figure 7(B). As a result, RPR04, which was previously connected, scans other access points that also use 100CH, finds EPR03, and connects to EPR03. For ease of explanation, an example is shown in which only EST01 is unable to use 100CH due to DFS.

[0057] Next, the operation of the wireless relay device 30 in this embodiment will be described. 8 to 10 are flowcharts showing the flow of processing for connecting to the optimal access point performed by the CPU 101 of the RPR04 in the wireless relay device 30. The CPU 101 reads, expands, and executes a program from the ROM 102 or the storage 104 to perform the processing.

[0058] In addition, in a typical example, this flowchart shows the processing when EST01, which RPR04 of the wireless relay device 30 was connected to on 100CH, changes to 104CH due to DFS, and RPR04's connection destination changes to EPR03 on 100CH. After that, RPR04 reconnects to EST01, which has returned from DFS.

[0059] In step S100, the CPU 101 reads out the Beacon list (see FIG. 6) stored in the storage 104. Then, the process proceeds to the next step S101.

[0060] In step S101, the CPU 101 acquires the radio wave strength of the current connection destination. Here, if the channel of EST01 to which RPR04 was connected has changed due to DFS, RPR04 is not connected to any access point, and so the acquired radio wave strength of the current connection destination is "0." Then, the process proceeds to the next step, S102.

[0061] In step S102, CPU 101 determines whether the radio wave strength of the current connection destination acquired in step S101 described above is greater than a switching threshold (for example, 50 dBm). If the radio wave strength of the current connection destination is greater than the switching threshold, the process ends. Here, the radio wave strength of the current connection destination is the average radio wave strength, but it may also be the latest radio wave strength in the Beacon list. The switching threshold is a predetermined radio wave strength, and is set to a value of radio wave strength that ensures sufficiently stable communication. In this way, by not changing the connection destination when the radio wave strength of the current connection destination is higher than the switching threshold, it is possible to reduce the process of switching access points and prevent communication from becoming unstable due to unnecessary switching of access points.

[0062] On the other hand, if the signal strength of the current connection destination is lower than the switching threshold, proceed to the next step S103. Here, if the channel of the connected EST01 has changed due to DFS, the signal strength of the current connection destination is "0" as described above, so proceed to the next step S103.

[0063] In step S103, CPU 101 checks whether there has been a change in the connection destination from the Beacon list read in step S100 described above. That is, it checks whether there is a new connection destination with a radio wave strength higher than the value obtained by adding a predetermined threshold to the radio wave strength of the current connection destination. If there is a new connection destination with a radio wave strength higher than the value obtained by adding a predetermined threshold to the radio wave strength of the current connection destination, the process proceeds to step S104. On the other hand, if there is no new connection destination with a radio wave strength higher than the radio wave strength of the current connection destination, the process proceeds to step S105 without going through step S104.

[0064] In step S104, the reconnection destination is set to a new connection destination with a stronger radio wave strength than the current connection destination confirmed in step S103. That is, in the case of a Beacon list such as that shown in Fig. 6, if the current connection destination is EPR03, the reconnection destination is set to EST01 with a stronger radio wave strength. Also, if the channel of the connected EST01 has changed due to DFS, EPR03 is set as the new reconnection destination because EST01 is not listed in the Beacon list. The reconnection destination set here is connected in the reconnection connection process performed in step S109, which will be described later. Then, the process proceeds to the next step, S105.

[0065] The processing in step S105 will be described with reference to FIG.

[0066] In step S200, the signal strength of the current connection destination is acquired by CPU 101. This process is the same as step S101 in Fig. 8. Then, the process proceeds to the next step S201.

[0067] In step S201, whether or not the current channel belongs to the DFS frequency band is determined by CPU 101. If it is determined that the current channel belongs to the DFS frequency band, the process proceeds to the next step S202.

[0068] In step S202, CPU 101 determines whether RPR04 is already connected to an access point (AP), or whether it is not yet connected but a reconnection destination has been set. If it is determined that it is already connected to an access point, the process proceeds to step S203. If it is determined that it is not yet connected but a reconnection destination has been set, for example, if the channel has been changed by DFS, the process proceeds to step S207, which will be described later. That is, if the channel of connected EST01 has been changed by DFS, RPR04 is in an unconnected state with no connection destination, but the reconnection destination has been set in step S104 of FIG. 8, as described above, the process proceeds to step S207. If it is not yet connected to an access point, for example, when the power is turned on, the process proceeds to step S221, which will be described later.

[0069] In step S203, the CPU 101 acquires the timestamp of the channel information file from the controller 10. Then, the process proceeds to the next step, S204. In step S204, it is determined whether the timestamp of the channel information file from the controller 10 has been updated in step S203 described above. If it is determined that the timestamp of the channel information file has been updated, the process proceeds to step S205. On the other hand, if it is not determined that the timestamp of the channel information file has been updated, the process ends and proceeds to step S106 in Fig. 8. That is, if EST01, which was 100CH, is changed to 104CH by DFS and EST01 of 104CH is registered in the channel information file, the timestamp of the channel information file has been updated, so the process proceeds to step S205. However, if EST01, which was 100CH, has been changed to 104CH by DFS, but EST01 of 104CH has not yet been registered in the channel information file, the timestamp of the channel information file has not been updated, so the process ends.

[0070] In step S205, the CPU 101 acquires the channel information file from the controller 10. Then, the process proceeds to the next step, S206.

[0071] In step S206, it is determined whether or not the channel information file was successfully acquired from the controller 10 in step S205 described above. If the channel information file was successfully acquired and the file contents are compared and it is determined that the file contents have been updated, the process proceeds to the next step S207. On the other hand, if the channel information file was successfully acquired and it is not determined that the file contents have been updated, the process ends and proceeds to step S106 in FIG. 8.

[0072] In step S207, the CPU 101 reads out the past connection destination history (see FIG. 5) stored in the storage 104. Then, the process proceeds to the next step, S208.

[0073] In step S208, it is determined whether or not the reading of the past connection destination history was successful in step S207 described above. If it is determined that the reading of the past connection destination history was successful, the process proceeds to the next step S209. On the other hand, if it is determined that the reading of the past connection destination history was not successful, the process ends and proceeds to step S106 in FIG. 8.

[0074] In step S209, CPU 101 determines whether the past signal strength is greater than the sum of the current signal strength and a threshold. That is, if the previous connection was made to an access point with a signal strength greater than the signal strength of the current connection destination plus a predetermined threshold, e.g., 3 dBm, the process proceeds to step S210. On the other hand, if the previous connection was not made to an access point with a signal strength greater than the signal strength of the current connection destination plus the predetermined threshold, the process ends and proceeds to step S106 in FIG. 8. That is, if the previous connection was made to an access point with a signal strength greater than the signal strength of the current connection destination plus the predetermined threshold, the process assumes that an access point with a stronger signal strength exists. On the other hand, if no access point with a stronger signal strength exists, the process does not change the connection destination, thereby reducing the number of access point switching processes and preventing communication instability due to unnecessary access point switching. For example, if the previous connection is made to EST01, the access point with the best signal strength, or if EST01 has been removed from the Beacon list by DFS and only EPR03 remains, the process proceeds to NO. On the other hand, if you are currently connected to EPR03 and EST01 exists, proceed to YES.

[0075] In step S210, the optimal device in the past connection destination history is obtained from the channel information file obtained in step S203 described above. Here, the optimal device in the past connection destination history means obtaining channel information for the access point with the strongest radio wave intensity from the access points recorded in the channel information file. That is, in the case of the channel information file of Figure 4(B), EST01 is the optimal device, so information on 104CH from EST01 is obtained. Then, proceed to the next step S211.

[0076] In step S211, it is determined whether or not the acquisition of the optimal device in the past connection destination history from the channel information file was successful in step S210 described above. If it is determined that the acquisition of the optimal device in the past connection destination history was successful, the process proceeds to the next step S212. On the other hand, if it is determined that the acquisition of the optimal device in the past connection destination history was not successful, the process ends and proceeds to step S106 in FIG. 8.

[0077] In step S212, a designated channel scan is set to scan only the designated channel, and the process ends, and the flow proceeds to step S106 in FIG.

[0078] In step S201 described above, if it is not determined that the current channel belongs to the DFS frequency band, that is, if the current channel is 2.4 GHz or W52, which is not a DFS frequency band, the process proceeds to step S220.

[0079] In step S220, CPU 101 determines whether or not automatic setting is set, which selects and sets a channel with high radio wave strength, etc. If it is determined that automatic setting is set, the process proceeds to the next step S221.

[0080] In step S221, an all-channel scan is set to scan all channels, and the process ends, and the flow proceeds to step S106 in FIG.

[0081] If it is determined in step S220 that the automatic setting is not set, the process proceeds to step S222, where a designated channel scan is set to scan only designated channels, and the process then ends, and the process proceeds to step S106 in FIG.

[0082] In step S106 of Fig. 8, it is determined whether or not a scan setting is present. That is, it is determined whether or not the scan setting is present in the above-mentioned steps S212, S221, and S222. If a scan setting is present, the process proceeds to the next step S107. On the other hand, if it is not determined that a scan setting is present, the process proceeds to step S108 without passing through step S107.

[0083] The processing in step S107 will be described with reference to FIG.

[0084] In step S300, it is determined whether or not the scan setting is an all-channel scan setting. That is, it is determined whether or not the scan setting set in step S221 of Fig. 9 is present. If it is determined that an all-channel scan setting is present, the process proceeds to the next step S301. Furthermore, if the current channel is in the DFS frequency band, the connection destination is cleared and the process proceeds to the next step S301.

[0085] In step S301, all channels are scanned, and the process proceeds to step S303.

[0086] On the other hand, if it is determined in step S300 that all channel scan settings are not present, that is, if the specified channel scan settings are present in steps S212 and S222, the process proceeds to step S302.

[0087] In step S302, the channels obtained from the channel information file are scanned, and the process proceeds to step S303.

[0088] In step S303, it is determined whether the connection destination will be changed based on the results of the scans in steps S301 and S302. That is, it is determined whether the scan has discovered an access point with stronger radio wave intensity than the currently connected access point. If it is determined that the connection destination will be changed, the process proceeds to the next step, S304. On the other hand, if it is not determined that the connection destination will be changed, the process ends and proceeds to step S108 in FIG. 8.

[0089] In step S304, the reconnection destination is set. If a reconnection destination has been set in step S104 of Fig. 8, it is overwritten. The reconnection destination set here is connected to in the reconnection connection process performed in step S109, which will be described later. Then, the process ends, and the process proceeds to step S108 of Fig. 8.

[0090] In step S108 of Fig. 8, it is determined whether or not a reconnection destination has been set. That is, in steps S104 and S304 described above, it is determined whether or not a reconnection destination has been set. If it is determined that a reconnection destination has been set, the process proceeds to the next step S109. On the other hand, if it is determined that a connection has already been established and no reconnection destination has been set, the process ends. If there is no connection destination, the process returns to step S107 described above. Here, cases where there is no connection destination include when the RPR04 is powered on, or when another access point is in standby mode after changing channels using DFS and no access points are found even after scanning.

[0091] In step S109, a connection process is performed to the set reconnection destination, and the process then proceeds to the next step, S110.

[0092] In step S110, it is determined whether the connection process to the reconnection destination was successful in step S109 described above. If it is determined that the connection process to the reconnection destination was successful, the process ends. On the other hand, if it is determined that the connection process to the reconnection destination was not successful, the process proceeds to the next step S111.

[0093] In step S111, the reconnection destination is cleared. That is, if there is a reconnection destination set in step S104 or step S304, it is cleared. Then, the process returns to step S107.

[0094] The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

[0095] According to the present embodiment, it is possible to provide communication devices 20A, 20B, 30A, and 30B that can perform stable communication by preventing a time consuming search for an access point with high radio wave intensity. That is, even if the channel is changed by DFS, by limiting the channels to be searched, it is possible to reduce the search process compared to searching all channels, and it is also possible to prevent communication from being interrupted due to channel switching during the search. [Explanation of symbols]

[0096] 1. Order Management System 10 Controllers 20. Communication Equipment 30 Communication equipment 110 Transmitter 120 Receiver 130 Search Department

Claims

1. a transmitter that transmits to the server, identification information that distinguishes the device having the access point function from other communication devices having the access point function, and channel information that includes information about a channel of wireless communication with the other communication device to which the device is currently connected; a storage unit that stores a connection history including radio wave intensity for each of the other communication devices to which the device itself is connected; a receiving unit that receives the channel information including information on the other communication devices from the server; A communication device comprising: a search unit that, when the channel for wireless communication with the other communication device to which the device is currently connected is a channel in a predetermined frequency band, and the connection history includes a communication device with a stronger radio wave strength than the radio wave strength of the other communication device to which the device is currently connected, searches for a connection destination within the range between the channel listed in the channel information of the communication device with the stronger radio wave strength and the channel for wireless communication with the communication device to which the device is currently connected.

2. The communication device according to claim 1 , wherein the predetermined frequency band is a DFS (Dynamic Frequency Selection) frequency band.

3. The communication device according to claim 1 , wherein the search unit executes the search when radio wave strength is stronger than a value obtained by adding a predetermined value to the radio wave strength of the other communication device to which the communication device is currently connected.

4. a communication device; a plurality of other communication devices connected to the communication device; a server to which the communication device and the other communication device are connected, The communication device a transmitter that transmits to the server, identification information that distinguishes the device having the access point function from other communication devices having the access point function, and channel information that includes information about a channel of wireless communication with the other communication device to which the device is currently connected; a storage unit that stores a connection history including radio wave intensity for each of the other communication devices to which the device itself is connected; a receiving unit that receives the channel information including information on the other communication devices from the server; A wireless communication system comprising: a search unit that, if the connection history contains a communication device with a radio wave strength stronger than the radio wave strength of the other communication device currently connected, searches for a connection destination within the range between the channel listed in the channel information of the communication device with the stronger radio wave strength and the wireless communication channel with the communication device currently connected.

5. On the computer, transmits to a server identification information for distinguishing the device having the access point function from other communication devices having the access point function, and channel information including information on a channel for wireless communication with the other communication device to which the device is currently connected; storing a connection history including radio wave strength for each of the other communication devices to which the own device has connected; receiving the channel information including information on the other communication devices from the server; If the connection history contains a communication device with a stronger radio wave strength than the other communication device currently connected, the program executes a process to search for a connection destination within the range between the channel listed in the channel information of the communication device with the stronger radio wave strength and the wireless communication channel with the communication device currently connected.

Images