JP7322524B2 - Communication system and communication device - Google Patents

Description

The present invention relates generally to communication systems and communication devices, and more particularly to communication systems and communication devices comprising a plurality of communication devices.

Conventionally, a wireless LAN communication control device (second communication device) that controls wireless communication between a wireless LAN access point and a communication terminal (first communication device) is known (see Patent Document 1, for example). The wireless LAN communication control device described in Patent Document 1 includes a communication status detection section (detection section) and a switching control section (second switching section).

The communication status detector detects the communication status of the wireless LAN access point for each communication channel of a plurality of wireless LAN communication schemes. The switching control section switches the wireless LAN communication method and communication channel between the wireless LAN access point and the communication terminal according to the communication status detected by the communication status detection section.

JP 2011-188122 A

In the wireless LAN communication control device described in Patent Document 1, for example, when switching communication channels in a wireless communication method such as Wi-Fi (registered trademark), wireless communication is started after performing a predetermined connection process. There was a problem that communication was interrupted temporarily.

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication system and a communication device that can maintain communication quality and make communication less likely to be interrupted.

A communication system according to an aspect of the present invention includes a first communication device and a second communication device that communicates with the first communication device. The first communication device has a first communication circuit, a second communication circuit, a third communication circuit, and a first switching section. The first switching unit switches so that data communication is performed by one of the first communication circuit and the second communication circuit. The second communication device has a fourth communication circuit, a fifth communication circuit, a sixth communication circuit, a second switching section, and a detection section. The fourth communication circuit communicates with the first communication circuit in a first communication scheme. The fifth communication circuit communicates with the second communication circuit by a second communication method different from the first communication method. The sixth communication circuit communicates with the third communication circuit at least in a third communication scheme different from the first communication scheme. The second switching unit switches so that data communication is performed by one of the fourth communication circuit and the fifth communication circuit. The detection unit detects deterioration of communication quality from values indicating communication quality of communication between the first communication circuit and the fourth communication circuit and communication between the second communication circuit and the fifth communication circuit. to detect When data communication is performed by the first communication circuit and data communication is performed by the fourth communication circuit, the second communication circuit and the fifth communication circuit complete predetermined connection processing and Communication is possible. The sixth communication circuit transmits a switching signal to the third communication circuit according to the detection result of the detection unit. The second switching unit switches data communication by the fourth communication circuit to data communication by the fifth communication circuit according to the detection result of the detection unit. The first switching unit switches data communication by the first communication circuit to data communication by the second communication circuit when the third communication circuit receives the switching signal. The first communication device further includes a first detector that detects deterioration of the communication quality, unlike the second detector as the detector. The third communication circuit transmits a first switching signal different from the second switching signal as the switching signal to the sixth communication circuit according to the detection result of the first detection unit. The first switching section switches the data communication by the first communication circuit to the data communication by the second communication circuit according to the detection result of the first detection section. The second switching unit switches the data communication by the fourth communication circuit to the data communication by the fifth communication circuit when the sixth communication circuit receives the first switching signal. The first switching signal and the second switching signal are different signals.

A communication device according to an aspect of the present invention is a communication device configured to communicate with a counterpart communication device. The communication device has a first communication circuit, a second communication circuit, a first switching section, and a first detection section . The first switching unit switches so that data communication is performed by one of the first communication circuit and the second communication circuit. A said 1st detection part detects deterioration of communication quality from the value which shows the communication quality of a said 1st communication circuit and a said 2nd communication circuit. The counterparty communication device has a counterparty first communication circuit, a counterparty second communication circuit, a second switching section, and a second detection section. The counterpart first communication circuit communicates with the first communication circuit in a first communication scheme. The counterparty second communication circuit communicates with the second communication circuit by a second communication method different from the first communication method. The second switching unit switches so that data communication is performed by one of the counterparty first communication circuit and the counterparty second communication circuit. The second detection unit detects deterioration in communication quality from values indicating communication quality of the counterparty first communication circuit and the counterparty second communication circuit. In the communication device, when data communication is performed by the first communication circuit, the second communication circuit performs a predetermined connection process when the first detection unit does not detect deterioration of the communication quality of the first communication circuit. Stay complete. In the communication device, when data communication is performed by the first communication circuit, the second communication circuit outputs the first switching signal when the first detection unit detects deterioration of the communication quality of the first communication circuit . The data is transmitted to the counterpart second communication circuit , and the first switching unit switches data communication by the first communication circuit to data communication by the second communication circuit. In the counterparty communication device, when data communication is performed by the counterparty first communication circuit, when the second detection unit does not detect deterioration of the communication quality of the counterparty first communication circuit, the counterparty second communication circuit connection processing is completed. In the counterparty communication device, when data communication is performed by the counterparty first communication circuit, when the second detection unit detects the deterioration of the communication quality of the counterparty first communication circuit, the counterparty second communication circuit 2 switching signal is transmitted to the second communication circuit, and the second switching unit switches data communication by the partner first communication circuit to data communication by the partner second communication circuit. The first switching unit switches the data communication by the first communication circuit to the data communication by the second communication circuit when the second communication circuit receives the second switching signal. The second switching unit switches the data communication by the counterparty first communication circuit to the data communication by the counterparty second communication circuit when the counterparty second communication circuit receives the first switching signal. The first switching signal and the second switching signal are different signals.

ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that communication can be made hard to be interrupted, maintaining communication quality.

FIG. 1 is a block diagram showing the configuration of a communication system according to an embodiment. 2A and 2B are diagrams showing formats of frames transmitted and received in the same communication system. FIG. 3 is a flow chart for explaining the operation of the same communication system. FIG. 4 is a schematic diagram for explaining a test method for worsening the radio wave environment in the same communication system. FIG. 5 is a schematic diagram for explaining a method of measuring a value indicating communication quality of the communication system; FIG. 6 is a block diagram showing the configuration of a communication system according to Modification 1 of the embodiment. FIG. 7 is a block diagram showing the configuration of a communication system according to Modification 2 of the embodiment. FIG. 8 is a block diagram showing the configuration of a communication system according to Modification 3 of the embodiment.

Hereinafter, communication systems according to embodiments will be described with reference to the drawings.

4 and 5, which are referred to in the following embodiments, etc., are schematic diagrams, and the ratio of the size and thickness of each component in the diagram does not necessarily reflect the actual dimensional ratio. Not necessarily.

(embodiment)
(1) Overall Configuration of Communication System First, the overall configuration of a communication system 10 according to an embodiment will be described with reference to FIG.

A communication system 10 according to the embodiment includes a first communication device 1 and a second communication device 2 that communicates with the first communication device 1, as shown in FIG. The first communication device 1 is, for example, a station (STA) consisting of a personal computer. The second communication device 2 is, for example, a wireless access point (AP) made up of a personal computer. In this embodiment, the first communication device 1 and the second communication device 2 constitute a wireless LAN (Local Area Network).

The first communication device 1 has a first communication module 101, a second communication module 102, a third communication module 103, and a first control section 104, as shown in FIG. The first communication module 101 includes a first antenna 11 and a first communication circuit 14 electrically connected to the first antenna 11 . A second communication module 102 includes a second antenna 12 and a second communication circuit 15 electrically connected to the second antenna 12 . Third communication module 103 includes third antenna 13 and third communication circuit 16 electrically connected to third antenna 13 . First control section 104 includes a first switching section 17 and a first information input/output section 18 . The first switching unit 17 switches so that either one of the first communication circuit 14 and the second communication circuit 15 performs data communication. In this specification and the like, "data" refers to data such as documents, video, audio, etc., and is transmitted using data frames. Management frames and control frames, which will be described later, are not included in "data" in this specification. That is, in the following description, data transmitted by a communication circuit that performs data communication is "data" in this specification and the like.

The second communication device 2 has a fourth communication module 201, a fifth communication module 202, a sixth communication module 203, and a second control section 204, as shown in FIG. The fourth communication module 201 includes a fourth antenna 21 and a fourth communication circuit 24 electrically connected to the fourth antenna 21 . A fifth communication module 202 includes a fifth antenna 22 and a fifth communication circuit 25 electrically connected to the fifth antenna 22 . A sixth communication module 203 includes a sixth antenna 23 and a sixth communication circuit 26 electrically connected to the sixth antenna 23 . Second control section 204 includes second switching section 27 , second information input/output section 28 , and detection section 31 . The second switching unit 27 switches so that either one of the fourth communication circuit 24 and the fifth communication circuit 25 performs data communication. The detection unit 31 determines the communication quality from the value indicating the communication quality of the communication between the first communication circuit 14 and the fourth communication circuit 24 and the communication between the second communication circuit 15 and the fifth communication circuit 25. Detect degradation. Incidentally, when simply referring to the communication quality of the first communication circuit 14, it indicates the communication quality between the first communication circuit 14 and the second communication device 2, or indicates the communication quality of the communication between the fourth communication circuit 24. show. The value indicating the communication quality is, for example, the received signal strength indicator (RSSI) of the received signal (radio signal) received by the fourth communication circuit 24 and the fifth communication circuit 25, and the transmission of data per unit time. It includes both the data rate (data transfer rate) that indicates the amount (communication volume). That is, the detection unit 31 detects deterioration of communication quality based on the RSSI and data rate obtained by the fourth communication circuit 24 and the fifth communication circuit 25 . In this embodiment, the RSSI is the first quality value and the data rate is the second quality value.

In the communication system 10, the first communication module 101 and the fourth communication module 201 correspond. Then, the fourth communication circuit 24 of the fourth communication module 201 communicates with the first communication circuit 14 of the first communication module 101 using the first communication method. Also, in the communication system 10, the second communication module 102 and the fifth communication module 202 correspond. And the 5th communication circuit 25 of the 5th communication module 202 communicates with the 2nd communication circuit 15 of the 2nd communication module 102 by the 2nd communication method different from the 1st communication method. Also, in the communication system 10, the third communication module 103 and the sixth communication module 203 correspond. Then, the sixth communication circuit 26 of the sixth communication module 203 communicates with the third communication circuit 16 of the third communication module 103 by at least a third communication method different from the first communication method.

(2) Components of Communication System Next, components of the communication system 10 according to the embodiment will be described with reference to FIG.

(2.1) First Communication Device As shown in FIG. , have

(2.1.1) First Communication Module The first communication module 101 includes a first antenna 11 and a first communication circuit 14, as shown in FIG. The first communication circuit 14 is electrically connected to the first antenna 11 .

The first communication circuit 14 is configured to wirelessly communicate with the fourth communication circuit 24 of the fourth communication module 201 via the first antenna 11 . The first communication method, which is the communication method between the first communication circuit 14 and the fourth communication circuit 24, is Wi-Fi (registered trademark) compliant with IEEE802.11b, IEEE802.11g, IEEE802.11n or IEEE802.11ac, for example. is. In this embodiment, the first communication circuit 14 and the fourth communication circuit 24 conform to IEEE802.11n or IEEE802.11ac and perform wireless communication using a frequency of 5 GHz band. A first communication channel, which is a communication channel between the first communication circuit 14 and the fourth communication circuit 24, is, for example, 52ch.

(2.1.2) Second Communication Module The second communication module 102 includes the second antenna 12 and the second communication circuit 15, as shown in FIG. The second communication circuit 15 is electrically connected to the second antenna 12 .

The second communication circuit 15 is configured to wirelessly communicate with the fifth communication circuit 25 of the fifth communication module 202 via the second antenna 12 . The second communication method, which is the communication method between the second communication circuit 15 and the fifth communication circuit 25, is, for example, Wi-Fi conforming to IEEE802.11b, IEEE802.11g, IEEE802.11n or IEEE802.11ac. In this embodiment, the second communication circuit 15 and the fifth communication circuit 25 conform to IEEE802.11b or IEEE802.11g and perform wireless communication using a frequency of 2.4 GHz band. A second communication channel, which is a communication channel between the second communication circuit 15 and the fifth communication circuit 25, is, for example, 1ch.

(2.1.3) Third Communication Module The third communication module 103 includes the third antenna 13 and the third communication circuit 16, as shown in FIG. The third communication circuit 16 is electrically connected to the third antenna 13 .

The third communication circuit 16 is configured to wirelessly communicate with the sixth communication circuit 26 of the sixth communication module 203 via the third antenna 13 . A third communication method, which is a communication method between the third communication circuit 16 and the sixth communication circuit 26, is, for example, BLE (Bluetooth (registered trademark) Low Energy). Therefore, in this embodiment, the third communication method is different from the first communication method and the second communication method. The third communication circuit 16 and the sixth communication circuit 26 perform wireless communication using frequencies in the 2.4 GHz band.

Thus, in this embodiment, the third communication method is different from both the first communication method and the second communication method. Note that the third communication method may be at least different from the first communication method, and may be the same as the second communication method.

(2.1.4) First Control Section The first control section 104 includes a first switching section 17 and a first information input/output section 18, as shown in FIG. The first control unit 104 controls the first communication circuit 14, the second communication circuit 15, and the third communication circuit 16, respectively.

The first control unit 104 is mainly composed of, for example, a computer system having one or more processors and one or more memories. The functions of the first control unit 104 (including the first switching unit 17 and the first information input/output unit 18) are realized by the processor of the computer system executing the program recorded in the memory of the computer system. be. The program may be prerecorded in a memory, or may be provided by being recorded in a non-temporary recording medium such as a memory card or through an electric communication line such as the Internet.

(2.1.4.1) First Switching Unit The first switching unit 17 performs data communication by changing the IP address for the first communication circuit 14 and the IP address for the second communication circuit 15. The communication circuit is switched between the first communication circuit 14 and the second communication circuit 15. - 特許庁For example, assume that an IP address of 192.168.0.2 is assigned to the first communication device 1 . Also, the IP address for the first communication circuit 14 is set to 192.168.0.2, the IP address for the second communication circuit 15 is set to 0.0.0.0, and the first communication circuit 14 are performing data communication. Hereinafter, among the communication circuits that perform data communication, the communication circuit on the side of the first communication device 1 is also referred to as the "first circuit 5".

In this case, for example, when the communication quality of communication between the first communication circuit 14 and the fourth communication circuit 24 deteriorates, the first switching unit 17 switches from the first communication circuit 14 to The first circuit 5 is switched to the second communication circuit 15 . That is, the first switching unit 17 switches data communication by the first communication circuit 14 to data communication by the second communication circuit 15 . At this time, the first switching unit 17 changes the IP address for the first communication circuit 14 from 192.168.0.2 to 0.0.0.0, and changes the IP address for the second communication circuit 15 to , from 0.0.0.0 to 192.168.0.2. That is, the first switching unit 17 switches the IP address for the first communication circuit 14 and the IP address for the second communication circuit 15 . Thereby, the first circuit 5 is switched from the first communication circuit 14 to the second communication circuit 15 . Also, at this time, the first switching unit 17 changes the communication channel of the first communication method from 52ch to 36ch, for example, because the communication quality of the first communication method is degraded.

(2.1.4.2) First Information Input/Output Unit The first information input/output unit 18 outputs the first information to the first circuit 5 (here, the first communication circuit 14). Further, the first information input/output unit 18 outputs the second information to the communication circuit for backup (here, the second communication circuit 15). The first information includes, for example, management frames, control frames, data frames, and the like. The second information includes, for example, management frames, control frames, and the like. That is, the second information does not include data frames.

(2.2) Second Communication Device The second communication device 2 includes a fourth communication module 201, a fifth communication module 202, a sixth communication module 203, and a second control section 204, as shown in FIG. , have

(2.2.1) Fourth Communication Module The fourth communication module 201 includes a fourth antenna 21 and a fourth communication circuit 24, as shown in FIG. The fourth communication circuit 24 is electrically connected to the fourth antenna 21 .

The fourth communication circuit 24 is configured to wirelessly communicate with the first communication circuit 14 via the fourth antenna 21 . The fourth communication circuit 24 communicates with the first communication circuit 14 using the first communication method.

(2.2.2) Fifth Communication Module The fifth communication module 202 includes a fifth antenna 22 and a fifth communication circuit 25, as shown in FIG. The fifth communication circuit 25 is electrically connected to the fifth antenna 22 .

The fifth communication circuit 25 is configured to wirelessly communicate with the second communication circuit 15 via the fifth antenna 22 . The fifth communication circuit 25 communicates with the second communication circuit 15 using the second communication method.

(2.2.3) Sixth Communication Module The sixth communication module 203 includes a sixth antenna 23 and a sixth communication circuit 26, as shown in FIG. The sixth communication circuit 26 is electrically connected to the sixth antenna 23 .

The sixth communication circuit 26 is configured to wirelessly communicate with the third communication circuit 16 via the sixth antenna 23 . The sixth communication circuit 26 communicates with the third communication circuit 16 using the third communication method.

(2.2.4) Second Control Unit The second control unit 204 includes a second switching unit 27, a second information input/output unit 28, and a detection unit 31, as shown in FIG. The second control unit 204 controls the fourth communication circuit 24, the fifth communication circuit 25, and the sixth communication circuit 26, respectively.

The second control unit 204 is mainly composed of, for example, a computer system having one or more processors and one or more memories. Then, the program recorded in the memory of the computer system is executed by the processor of the computer system, so that the second control unit 204 (including the second switching unit 27, the second information input/output unit 28, and the detection unit 31) function is realized. The program may be prerecorded in a memory, or may be provided by being recorded in a non-temporary recording medium such as a memory card or through an electric communication line such as the Internet.

(2.2.4.1) Second switching unit The second switching unit 27 performs data communication by changing the IP address for the fourth communication circuit 24 and the IP address for the fifth communication circuit 25. The communication circuit is switched between the fourth communication circuit 24 and the fifth communication circuit 25. - 特許庁For example, assume that the IP address of 192.168.0.1 is assigned to the second communication device 2 . Also, the IP address for the fourth communication circuit 24 is set to 192.168.0.1, the IP address for the fifth communication circuit 25 is set to 0.0.0.0, and the fourth communication circuit 24 are communicating. Hereinafter, among the communication circuits that perform data communication, the communication circuit on the side of the second communication device 2 is also referred to as the "second circuit 6".

In this case, for example, when the communication quality of communication between the first communication circuit 14 and the fourth communication circuit 24 deteriorates, the second switching unit 27 switches from the fourth communication circuit 24 to the fifth communication circuit 25. The second circuit 6 is switched. That is, the second switching unit 27 switches data communication by the fourth communication circuit 24 to data communication by the fifth communication circuit 25 . At this time, the second switching unit 27 changes the IP address for the fourth communication circuit 24 from 192.168.0.1 to 0.0.0.0, and changes the IP address for the fifth communication circuit 25 to , from 0.0.0.0 to 192.168.0.1. That is, the second switching unit 27 switches the IP address for the fourth communication circuit 24 and the IP address for the fifth communication circuit 25 . Thereby, the second circuit 6 is switched from the fourth communication circuit 24 to the fifth communication circuit 25 . Also, at this time, the second switching unit 27 changes the communication channel of the first communication method from 52ch to 36ch, for example, because the communication quality of the first communication method is degraded.

The second switching unit 27 also creates a switching signal for switching the first circuit 5 and causes the created switching signal to be transmitted from the sixth communication circuit 26 to the third communication circuit 16 . In the first communication device 1, when the third communication circuit 16 receives the switching signal, the first switching unit 17 switches the first circuit 5 from the first communication circuit 14 to the second communication circuit 15 according to this switching signal. In this case, it is preferable to synchronize the timing at which the first switching section 17 switches the first circuit 5 and the timing at which the second switching section 27 switches the second circuit 6 . As a result, the first circuit 5 and the second circuit 6 can be switched at the same timing, and communication is less likely to be interrupted than when the two timings are not synchronized.

(2.2.4.2) Second information input/output unit The second information input/output unit 28 outputs the first information to the second circuit 6 (here, the fourth communication circuit 24). The second information input/output unit 28 also outputs the second information to the backup communication circuit (here, the fifth communication circuit 25).

(2.2.4.3) Detector The detector 31 detects deterioration in communication quality from a value indicating communication quality of communication between the first circuit 5 and the second circuit 6 . The value indicating the communication quality is, for example, the RSSI and data rate of the received signal received by the second circuit 6 , in other words, the transmitted signal transmitted by the first circuit 5 . That is, the value indicating the communication quality is the RSSI and data rate obtained by the fourth communication circuit 24 and the fifth communication circuit 25 .

Based on the value indicating the communication quality, the detection unit 31 determines the communication quality of the communication between the first communication circuit 14 and the fourth communication circuit 24 and the communication quality of the second communication circuit 15 and the fifth communication circuit 25. determine the communication quality of communication between Specifically, the detection unit 31 determines the communication quality based on the combination of the RSSI and the data rate of the reception signal received by one of the fourth communication circuit 24 and the fifth communication circuit 25 .

表１は、ＩＥＥＥ８０２．１１ｇの場合におけるＲＳＳＩとデータレートとの組み合わせを示す図である。表１における「×」では、電波干渉が発生し、通信の通信品質が低下する可能性がある。したがって、検出部３１は、ＲＳＳＩとデータレートとの組み合わせが「×」の場合には、第１回路５と第２回路６との間の通信の通信品質が低下しており、第１回路５及び第２回路６の切り替えが必要であると判定する。表１に示す例では、検出部３１は、ＲＳＳＩが－４０、－３０又は－２０で、かつデータレートが１Ｍｂｐｓ又は６Ｍｂｐｓの場合に、第１回路５及び第２回路６の切り替えが必要であると判定する。ここで、本実施形態では、第２通信回路１５と第５通信回路２５との間の無線通信がＩＥＥＥ８０２．１１ｇに準拠しているため、検出部３１は、第２通信回路１５と第５通信回路２５との通信時に、表１に示す組み合わせに基づいて上記通信品質を判定する。

Table 1 is a diagram showing combinations of RSSI and data rate in the case of IEEE802.11g. With "x" in Table 1, there is a possibility that radio wave interference will occur and the communication quality will deteriorate. Therefore, when the combination of the RSSI and the data rate is "x", the detection unit 31 determines that the communication quality of the communication between the first circuit 5 and the second circuit 6 is degraded, and the first circuit 5 and the switching of the second circuit 6 is necessary. In the example shown in Table 1, the detector 31 needs to switch between the first circuit 5 and the second circuit 6 when the RSSI is -40, -30 or -20 and the data rate is 1 Mbps or 6 Mbps. I judge. Here, in the present embodiment, since the wireless communication between the second communication circuit 15 and the fifth communication circuit 25 conforms to IEEE802.11g, the detection unit 31 communicates between the second communication circuit 15 and the fifth communication circuit. During communication with the circuit 25, the communication quality is determined based on the combinations shown in Table 1.

表２は、ＩＥＥＥ８０２．１１ｎ又はＩＥＥＥ８０２．１１ａｃの場合におけるＲＳＳＩとデータレートとの組み合わせを示す図である。表２に示す例では、検出部３１は、ＲＳＳＩが－４０、－３０又は－２０で、かつデータレートがＭＣＳ０、ＭＣＳ１又はＭＣＳ２の場合に、第１回路５及び第２回路６の切り替えが必要であると判定する。ここで、本実施形態では、第１通信回路１４と第４通信回路２４との間の無線通信がＩＥＥＥ８０２．１１ｎ又はＩＥＥＥ８０２．１１ａｃに準拠しているため、検出部３１は、第１通信回路１４と第４通信回路２４との通信時に、表２に示す組み合わせに基づいて上記通信品質を判定する。

Table 2 shows combinations of RSSI and data rate for IEEE802.11n or IEEE802.11ac. In the example shown in Table 2, the detector 31 needs to switch between the first circuit 5 and the second circuit 6 when the RSSI is -40, -30 or -20 and the data rate is MCS0, MCS1 or MCS2. It is determined that Here, in the present embodiment, the wireless communication between the first communication circuit 14 and the fourth communication circuit 24 conforms to IEEE802.11n or IEEE802.11ac. and the fourth communication circuit 24, the communication quality is determined based on the combinations shown in Table 2.

Then, the second switching unit 27 switches the second circuit 6 when the detecting unit 31 determines that switching between the first circuit 5 and the second circuit 6 is necessary.

By the way, the detection unit 31 controls the first circuit 5 and the second circuit 6, that is, the data communication, so that the value indicating the communication quality of the communication between the first circuit 5 and the second circuit 6 is equal to or higher than a predetermined threshold value. It is preferable to select a communication circuit that implements Thereby, communication between the first circuit 5 and the second circuit 6 can be further prevented from being interrupted.

(2.3) Frame Next, the format of frames transmitted and received in the communication system 10 according to the embodiment will be described with reference to FIGS. 2A and 2B.

FIG. 2A shows the format of a frame transmitted and received between the first circuit 5 and the second circuit 6 (hereinafter also referred to as "first frame"). Also, FIG. 2B shows the format of a frame (hereinafter also referred to as “second frame”) transmitted and received between communication circuits in the standby state. In this specification and the like, "a communication circuit in a standby state" means a circuit that is on standby to perform communication instead of the communication circuit when the communication quality between the communication circuits currently performing data communication deteriorates. A communication circuit that is in a state where For example, when the first communication circuit 14 and the fourth communication circuit 24 are performing data communication, the second communication circuit 15 and the fifth communication circuit 25 are communication circuits in the standby state. In this embodiment, when data communication is performed by the first communication circuit 14 and data communication is performed by the fourth communication circuit 24, the second communication circuit 15 and the fifth communication circuit 25 can communicate with each other. in good condition. Therefore, for example, when switching the first circuit 5 from the first communication circuit 14 to the second communication circuit 15 and switching the second circuit 6 from the fourth communication circuit 24 to the fifth communication circuit 25, there is an advantage that communication is less likely to be interrupted. There is

In this specification and the like, "communicable state" means, for example, in the case of Wi-Fi, a state in which predetermined connection processing required before starting wireless communication has been completed. Specifically, when the association procedure, authentication procedure, and IP address assignment are required, the association procedure and the authentication procedure have been completed.

Next, each configuration of the first frame and the second frame will be described with reference to FIGS. 2A and 2B.

The first frame includes a PLCP preamble, a PLCP header, and a PSDU, as shown in FIG. 2A. Also, in the first frame, the PSDU includes an IEEE802.11 header, first data, and FCS (Frame Check Sequence). A PLCP preamble is a bit string of a synchronization signal added to the beginning of an IEEE802.11 frame. The PLCP header is a header containing information such as modulation scheme (transmission rate) and data length. The IEEE802.11 header is a header containing information about the first data. The first data is data corresponding to the first information described above. FCS is an error code added to the frame.

The second frame includes a PLCP preamble, a PLCP header, and a PSDU, as shown in FIG. 2B. Also, in the second frame, the PSDU includes an IEEE 802.11 header, second data, and FCS. Note that the PLCP preamble, PLCP header, IEEE802.11 header, and FCS are the same as in the first frame, and descriptions thereof are omitted here. The second data is data corresponding to the second information described above. The traffic of the second data may include information other than the management frame and the control frame as long as it is about 10% of the traffic of the first data. In other words, the second data may contain the same information as the first data if the traffic of the second data is about 10% of the traffic of the first data. Here, when the second data is a management frame, the communication layer of the first data and the communication layer of the second data are different. Second data can be identified.

For example, when data communication is performed by the first communication circuit 14 and data communication is performed by the fourth communication circuit 24, communication between the second communication circuit 15 and the fifth communication circuit 25 in the standby state is performed. The amount is smaller than the amount of communication between the first communication circuit 14 and the fourth communication circuit 24 that are performing data communication.

(3) Operation of Communication System Next, operation of the communication system 10 according to the embodiment will be described with reference to FIG. Here, the first communication circuit 14 is the first circuit 5, the fourth communication circuit 24 is the second circuit 6, the first circuit 5 is the second communication circuit 15, and the second circuit 6 is the fifth communication circuit 25. , respectively.

In the second communication device 2, the detector 31 transmits and receives data between the first communication circuit 14 and the fourth communication circuit 24, and detects RSSI and data rate (step ST1). Then, the detection unit 31 determines the communication quality of the communication between the first circuit 5 and the second circuit 6 from the combination of the RSSI and the data rate (step ST2). Here, since the first communication circuit 14 and the fourth communication circuit 24 perform wireless communication conforming to IEEE802.11n or IEEE802.11ac, the communication quality is determined according to Table 2 above. Specifically, the detector 31 determines the communication quality depending on whether the RSSI is -40, -30 or -20 and the data rate is MCS0, MCS1 or MCS2. When the RSSI is −40, −30 or −20 and the data rate is MCS0, MCS1 or MCS2 (step ST2: Yes), the detection unit 31 determines that the communication quality has deteriorated. On the other hand, when the RSSI is −40, −30 or −20 and the data rate is not MCS0, MCS1 or MCS2 (step ST2: No), the detection unit 31 determines that the communication quality has not deteriorated. .

The second switching unit 27 creates a switching signal for switching the first circuit 5 when the detecting unit 31 detects the deterioration of the communication quality, and transmits the created switching signal from the sixth communication circuit 26 to the third communication circuit. 16 (step ST3). Further, the second switching unit 27 switches the second circuit 6 from the fourth communication circuit 24 to the fifth communication circuit 25 (step ST4). At this time, the second switching unit 27 switches the second circuit 6 by switching the IP address for the fourth communication circuit 24 and the IP address for the fifth communication circuit 25 .

In the first communication device 1, when the third communication circuit 16 receives the switching signal, the first switching unit 17 switches the first circuit 5 from the first communication circuit 14 to the second communication circuit 15 according to the switching signal ( step ST4). At this time, the first switching unit 17 switches the first circuit 5 by switching the IP address for the first communication circuit 14 and the IP address for the second communication circuit 15 .

Here, since the communication quality of the first communication channel, which is the communication channel of the first communication circuit 14, has deteriorated, the first switching unit 17 changes the first communication channel from 52ch to 36ch, for example. Thereafter, the second communication circuit 15 becomes the first circuit 5 , the fifth communication circuit 25 becomes the second circuit 6 , and wireless communication is performed between the second communication circuit 15 and the fifth communication circuit 25 . On the other hand, the first communication circuit 14 and the fourth communication circuit 24 are in a communicable state as a backup communication circuit until the communication quality of the communication between the second communication circuit 15 and the fifth communication circuit 25 deteriorates. wait at

Note that the frequency of detecting deterioration in communication quality is every several seconds (for example, every 3 seconds). When data communication is performed, deterioration of communication quality is detected from the RSSI and communication rate of data communication, and when data communication is not performed, data communication is performed to measure the value of communication quality. In the present embodiment, switching is performed when a deterioration in communication quality is detected even once.

(4) Various Methods (4.1) Test Method for Deteriorating Radio Wave Environment First, the test method for deteriorating the radio wave environment will be described with reference to FIG. Here, between the first communication device 1 and the second communication device 2, the communication channel between the first communication module 101 and the fourth communication module 201 is 36ch, and the communication between the second communication module 102 and the fifth communication module 202 is 36ch. A case of 100 channels is exemplified. Moreover, the case where the 1st communication module 101 and the 4th communication module 201 are performing wireless communication by 36ch is illustrated. That is, here, the second communication module 102 and the fifth communication module 202 are in a standby state as backup communication circuits.

In a situation where the first communication module 101 and the fourth communication module 201 are performing wireless communication on 36ch, for example, the interference wave generator 3 continuously generates interference waves on 36ch. In the second communication device 2, the detection unit 31 of the second control unit 204 detects that radio wave interference occurs because the data rate obtained by the fourth communication module 201 decreases due to the interference waves from the interference wave generation device 3. determined to be Then, the second switching unit 27 of the second control unit 204 switches the communication module for wireless communication from the fourth communication module 201 to the fifth communication module 202 . Also, in the first communication device 1 , the first switching unit 17 of the first control unit 104 switches the communication module for wireless communication from the first communication module 101 to the second communication module 102 . Thereafter, since the second communication module 102 and the fifth communication module 202 perform wireless communication with 100ch, the wireless communication is not hindered by the interference waves of 36ch.

(4.2) Method for Measuring RSSI and Data Rate Next, a method for measuring the RSSI and data rate of radio signals will be described with reference to FIG. Here, a case where the first communication module 101 and the fourth communication module 201 perform wireless communication is illustrated.

First, the first communication module 101 and the second communication module 102 of the first communication device 1 face the fourth communication module 201 and the fifth communication module 202 of the second communication device 2, and the first communication device 1 and The first communication device 1 and the second communication device 2 are arranged so that the distance from the second communication device 2 is 5 m. Next, the acquisition device 4 is arranged with respect to the second communication device 2 so that the distance from the second communication device 2 is 50 cm. The acquisition device 4 is a device that acquires the radio signal transmitted from the first communication device 1 to the second communication device 2 and detects the RSSI and data rate from the acquired radio signal, such as a wireless packet capture. Note that this acquisition device 4 can also measure the content of a frame, and can also measure the amount of communication from the amount of data in the frame. The larger the amount of data, the larger the amount of data communication, and the smaller the amount of data, the smaller the amount of data communication.

The acquisition device 4 acquires a radio signal transmitted from the first communication module 101 of the first communication device 1 to the fourth communication module 201 of the second communication device 2, and detects RSSI and data rate from the acquired radio signal. .

Here, for example, when data communication is performed between the first communication circuit 14 and the fourth communication circuit 24, a management frame and a control frame are transmitted between the second communication circuit 15 and the fifth communication circuit 25. If such transmission and reception are performed, the second communication circuit 15 and the fifth communication circuit 25 are in a communicable state.

(5) Effects In the communication system 10 according to the embodiment, for example, when the first communication circuit 14 and the fourth communication circuit 24 are performing data communication, the second communication circuit 15 and the fifth communication circuit 25 Communication is possible. Therefore, data communication can be started simply by switching the first circuit 5 from the first communication circuit 14 to the second communication circuit 15 and switching the second circuit 6 from the fourth communication circuit 24 to the fifth communication circuit 25. This makes it possible to maintain communication quality while making communication less likely to be interrupted.

Further, in the communication system 10 according to the embodiment, the first circuit 5 and the second circuit 6 are selected such that the communication quality of communication between the first circuit 5 and the second circuit 6 is equal to or higher than a predetermined threshold. there is Thereby, communication between the first circuit 5 and the second circuit 6 can be further prevented from being interrupted.

Further, in the communication system 10 according to the embodiment, the third communication method is different from the first communication method and the second communication method, thereby suppressing radio wave interference.

Further, in the communication system 10 according to the embodiment, the second communication traffic, which is the communication traffic between the second communication circuit 15 and the fifth communication circuit 25, is the first circuit 5 (the first communication circuit 14) and the second It is smaller than the first communication traffic, which is the communication traffic with the circuit 6 (fourth communication circuit 24). Thereby, energy saving can be achieved compared with the case where the 1st communication amount and the 2nd communication amount are about the same.

(6) Modification (6.1) Modification 1
In the above-described embodiment, only the second communication device 2 has the detection unit 31, but for example, as shown in FIG. The device 2 may have a second detection section 33 as the detection section 31 . A communication system 10A according to Modification 1 will be described below with reference to FIG. Below, the same reference numerals are given to the same configurations as in the above-described embodiment, and detailed description thereof will be omitted.

A communication system 10A according to Modification 1 includes a first communication device 1A and a second communication device 2, as shown in FIG.

The first communication device 1A has a first communication module 101, a second communication module 102, a third communication module 103, and a first control section 104A. First control unit 104A includes first switching unit 17 , first information input/output unit 18 , and first detection unit 32 .

The second communication device 2 has a fourth communication module 201 , a fifth communication module 202 , a sixth communication module 203 and a second control section 204 . The second control unit 204 includes a second switching unit 27, a second information input/output unit 28, and a second detection unit 33 (detection unit 31).

The first detection unit 32 detects deterioration of communication quality (whether communication is congested) from a value indicating the communication quality of communication between the first circuit 5 and the second circuit 6 . Specifically, the first detection unit 32 detects deterioration in communication quality of communication between the first circuit 5 and the second circuit 6 based on the RSSI and data rate obtained by the first circuit 5. . Specifically, the first detection unit 32, for example, when the RSSI is a first threshold or more (−40 dB or more) and the data rate is a second threshold or less (MCS2 or less, or 6 Mbps or less), the communication quality Detect degradation.

The first switching unit 17 switches the first circuit 5 when the first detection unit 32 detects the deterioration of the communication quality. Specifically, the first switching unit 17 switches the first circuit 5 by switching the IP address for the first communication circuit 14 and the IP address for the second communication circuit 15 . The first switching unit 17 also creates a first switching signal for switching the second circuit 6 and causes the created first switching signal to be transmitted from the third communication circuit 16 to the sixth communication circuit 26 . The first switching signal is a signal different from the second switching signal as a switching signal transmitted from the sixth communication circuit 26 to the third communication circuit 16 according to the detection result of the second detection unit 33 (detection unit 31). be.

In the second communication device 2, when the sixth communication circuit 26 receives the first switching signal, the second switching section 27 switches the second circuit 6 according to the first switching signal. Specifically, the second switching unit 27 switches the second circuit 6 by switching the IP address for the fourth communication circuit 24 and the IP address for the fifth communication circuit 25 .

Note that the case where the second detection unit 33 of the second communication device 2 detects deterioration of the communication quality is the same as in the above-described embodiment, and the description is omitted here.

In the communication system 10A according to Modification 1, each of the first communication device 1A and the second communication device 2 is configured to detect the communication quality of the communication between the first circuit 5 and the second circuit 6. . This makes it possible to cope with not only the communication status of the second communication device 2 side but also the communication status of the first communication device 1A side, so that the communication between the first circuit 5 and the second circuit 6 is more difficult to be interrupted. be able to.

(6.2) Modification 2
In the above-described embodiments, the first communication device 1 has the third communication circuit 16, the second communication device 2 has the sixth communication circuit 26, and the third communication circuit 16 and the sixth communication circuit 26 A switching signal is transmitted and received between On the other hand, as shown in FIG. 7, the switching signal may be transmitted and received between the second communication circuit 15 and the fifth communication circuit 25. FIG. In other words, the second communication circuit 15 and the third communication circuit 16 may be used in common, and the fifth communication circuit 25 and the sixth communication circuit 26 may be used in common. A communication system 10B according to Modification 2 will be described below with reference to FIG. Below, the same reference numerals are given to the same configurations as in the above-described embodiment, and detailed description thereof will be omitted.

A communication system 10B according to Modification 2 includes, as shown in FIG. 7, a first communication device 1B and a second communication device 2B.

The first communication device 1B has a first communication module 101, a second communication module 102, and a first control section 104. The first control section 104 includes a first switching section 17 and a first information input/output section. That is, in modification 2, the third communication module 103 is omitted.

The second communication device 2B has a fourth communication module 201, a fifth communication module 202, and a second control section 204. Second control section 204 includes second switching section 27 , second information input/output section 28 , and detection section 31 . That is, in modification 2, the sixth communication module 203 is omitted.

Here, it is assumed that the first communication circuit 14 is the first circuit 5 and the fourth communication circuit 24 is the second circuit 6 . In this case, the second communication circuit 15 and the fifth communication circuit 25 are backup communication circuits that are switched to the first circuit 5 and the second circuit 6, and transmit and receive switching signals for switching the first circuit 5. It is also a communication circuit for That is, the second communication circuit 15 also serves as the third communication circuit 16 , and the fifth communication circuit 25 also serves as the sixth communication circuit 26 . Therefore, in the second data of the second frame transmitted and received between the second communication circuit 15 and the fifth communication circuit 25, the communication between the second communication circuit 15 and the fifth communication circuit 25 is enabled. A management frame (beacon) for maintaining connection and a switching signal for switching the first circuit 5 are included.

Next, the operation of the communication system 10B according to Modification 2 will be described.

In the second communication device 2B, the detection unit 31 detects communication between the first circuit 5 and the second circuit 6 based on the RSSI and data rate obtained by the fourth communication circuit 24, which is the second circuit 6. Determine whether or not the communication quality is degraded.

The second switching unit 27 creates a switching signal for switching the first circuit 5 when the detecting unit 31 determines that the communication quality is degraded, and transmits the created switching signal from the fifth communication circuit 25. The second communication circuit 15 is made to transmit. Also, the second switching unit 27 switches the second circuit 6 .

In the first communication device 1B, when the second communication circuit 15 receives the switching signal, the first switching section 17 switches the first circuit 5 according to the switching signal.

When the first circuit 5 and the second circuit 6 are switched, the first communication circuit 14 and the fourth communication circuit 24 stand by as backup communication circuits. Therefore, in this case, the first communication circuit 14 and the third communication circuit 16 are used together, and the fourth communication circuit 24 and the sixth communication circuit 26 are used together.

In the communication system 10</b>B according to Modification 2, the second communication circuit 15 also serves as the third communication circuit 16 , and the fifth communication circuit 25 also serves as the sixth communication circuit 26 . Therefore, compared to the case where the second communication circuit 15 and the third communication circuit 16 are separately provided, and the fifth communication circuit 25 and the sixth communication circuit 26 are separately provided, the first communication device 1B and the 2, the size of the communication device 2B can be reduced.

(6.3) Modification 3
In the above-described embodiment, the first communication device 1 has one backup second communication circuit 15 and the second communication device 2 has one backup fifth communication circuit 25 . On the other hand, the first communication device 1C may have a plurality of second communication circuits 15, and the second communication device 2C may have a plurality of fifth communication circuits 25, as shown in FIG. A communication system 10C according to Modification 3 will be described below with reference to FIG. Below, the same reference numerals are given to the same configurations as in the above-described embodiment, and detailed description thereof will be omitted.

A communication system 10C according to Modification 3 includes, as shown in FIG. 8, a first communication device 1C and a second communication device 2C.

The first communication device 1C has one first communication module 101, a plurality of (two in FIG. 8) second communication modules 102, one third communication module 103, and a first control unit 104. . First control section 104 includes a first switching section 17 and a first information input/output section 18 .

The second communication device 2C has one fourth communication module 201, a plurality of (two in FIG. 8) fifth communication modules 202, one sixth communication module 203, and a second control section 204. . Second control section 204 includes second switching section 27 , second information input/output section 28 , and detection section 31 .

The plurality of second communication modules 102 and the plurality of fifth communication modules 202 are in one-to-one correspondence. Each of the plurality of second communication modules 102 communicates with the corresponding fifth communication module 202 among the plurality of fifth communication modules 202 .

The detection unit 31 acquires a value indicating the communication quality of each of the plurality of fifth communication circuits 25 from each of the plurality of fifth communication circuits 25 . The value indicating the communication quality is, for example, the RSSI and data rate of the received signal (radio signal) received by each of the plurality of fifth communication circuits 25 .

Here, a procedure for the detection unit 31 to acquire the RSSI and data rate will be described. In the first communication device 1</b>C, the first switching unit 17 sequentially switches the plurality of second communication circuits 15 one by one, and transmits the second frame via the switched second communication circuit 15 . The second frame includes a control frame as second data. On the other hand, in the second communication device 2C, the second switching unit 27 switches to the fifth communication circuit 25 corresponding to the second communication circuit 15 switched by the first switching unit 17 among the plurality of fifth communication circuits 25. , receives the second frame from the corresponding second communication circuit 15 via the switched fifth communication circuit 25 . The detector 31 acquires the RSSI and data rate of the second frame (received signal) obtained by the fifth communication circuit 25 . The detection unit 31 acquires the RSSI and data rate of the second frame each time the second switching unit 27 switches the fifth communication circuit 25 .

The detector 31 compares the communication quality of each fifth communication circuit 25 based on the RSSI and data rate obtained by each fifth communication circuit 25 . Then, the detection unit 31 selects, as the second circuit 6 , the fifth communication circuit 25 having the best communication quality among the plurality of fifth communication circuits 25 . The second switching unit 27 switches the second circuit 6 to the fifth communication circuit 25 selected by the detection unit 31 from among the plurality of fifth communication circuits 25 .

In the communication system 10C according to Modification 3, as described above, the first communication device 1C has a plurality of backup second communication circuits 15, and the second communication device 2C has a plurality of backup fifth communication circuits. 25. In this way, by increasing the number of switching destination options, it is possible to make communication more difficult to be interrupted compared to the case where each of the second communication circuit 15 and the fifth communication circuit 25 is one.

Further, in the communication system 10C according to Modification 3, the second switching unit 27 is configured to switch the second circuit 6 to the fifth communication circuit 25 having the highest communication quality among the plurality of fifth communication circuits 25. there is Thereby, the communication quality of communication between the first circuit 5 and the second circuit 6 can be improved.

Here, the first communication device 1C may have three or more second communication circuits 15, and the second communication device 2C may have three or more fifth communication circuits 25. FIG. In this case, there is a one-to-one correspondence between the three or more second communication circuits 15 and the three or more fifth communication circuits 25, and each of the three or more second communication circuits 15 corresponds to the three or more fifth communication circuits. It is preferable to communicate with the corresponding fifth communication circuit 25 out of the five communication circuits 25 .

(6.4) Other Modifications In the above-described embodiment, the first switching unit 17 replaces the IP address for the first communication circuit 14 and the IP address for the second communication circuit 15 to switch the first communication The first circuit 5 is switched between the circuit 14 and the second communication circuit 15 . Further, the second switching unit 27 switches between the fourth communication circuit 24 and the fifth communication circuit 25 by switching the IP address for the fourth communication circuit 24 and the IP address for the fifth communication circuit 25 . 2 circuits 6 are switched. On the other hand, the first switching section 17 and the second switching section 27 may switch the first circuit 5 and the second circuit 6 by the following method.

First, a virtual network interface is created for each of the first communication device 1 and the second communication device 2, and an IP address is assigned to this virtual network interface. The IP address for the virtual network interface of the first communication device 1 is, for example, 192.168.0.2. Also, the IP address for the virtual network interface of the second communication device 2 is, for example, 192.168.0.1.

For example, when the first communication circuit 14 is the first circuit 5 and the fourth communication circuit 24 is the second circuit 6, the first communication circuit 14 is set to "active" and the fourth communication circuit 24 is set to " "active". As a result, the first communication circuit 14 becomes the first circuit 5 and the fourth communication circuit 24 becomes the second circuit 6 .

The first switching unit 17 switches the first circuit 5 from the first communication circuit 14 to the second communication circuit 15 according to the switching signal from the second communication device 2 . Specifically, the first switching unit 17 changes the “active” communication circuit from the first communication circuit 14 to the second communication circuit 15 . Thereby, the first circuit 5 is switched from the first communication circuit 14 to the second communication circuit 15 .

The second switching unit 27 switches from the fourth communication circuit 24 to the fifth communication circuit 25 when the detection unit 31 detects deterioration in the communication quality of communication between the first circuit 5 and the second circuit 6 . Switch circuit 6. Specifically, the second switching unit 27 changes the “active” communication circuit from the fourth communication circuit 24 to the fifth communication circuit 25 . Thereby, the second circuit 6 is switched from the fourth communication circuit 24 to the fifth communication circuit 25 .

Through the above procedure, the first circuit 5 is switched from the first communication circuit 14 to the second communication circuit 15 and the second circuit 6 is switched from the fourth communication circuit 24 to the fifth communication circuit 25 .

In the above-described embodiments, the first communication device 1 has one first communication circuit 14 and the second communication device 2 has one fourth communication circuit 24. However, for example, the first communication device 1 may have a plurality of first communication circuits 14 and the second communication device 2 may have a plurality of fourth communication circuits 24 . In this case, the plurality of first communication circuits 14 and the plurality of fourth communication circuits 24 are preferably in one-to-one correspondence. Each of the plurality of first communication circuits 14 is preferably capable of communicating with the corresponding fourth communication circuit 24 among the plurality of fourth communication circuits 24 . According to this configuration, it becomes possible to transmit and receive more data.

In the above-described embodiment, the detector 31 determines the communication quality of communication between the first circuit 5 and the second circuit 6 from the combination of the RSSI obtained by the second circuit 6 and the data rate. On the other hand, the detection unit 31 may determine the communication quality using, for example, a ping command. Specifically, the detection unit 31 transmits the first message to the first communication device 1 by a ping command, and compares the return time of the second message with respect to the first message with the threshold. The detection unit 31 determines that the communication quality is degraded when the return time of the second message is longer than the threshold.

In the above-described embodiment, a frequency of 5 GHz is used for communication between the first communication circuit 14 and the fourth communication circuit 24, and a frequency of 2.4 GHz is used for communication between the second communication circuit 15 and the fifth communication circuit 25. are used, but these frequencies are only examples. Therefore, if communication between the first communication circuit 14 and the fourth communication circuit 24 and communication between the second communication circuit 15 and the fifth communication circuit 25 do not interfere with each other, other frequencies may be used. good.

(summary)
As described above, the communication system (10; 10A; 10B; 10C) according to the first aspect includes the first communication device (1; 1A; 1B; 1C) and the second communication device (2; 2B; 2C). ) and The second communication device (2; 2B; 2C) communicates with the first communication device (1; 1A; 1B; 1C). A first communication device (1; 1A; 1B; 1C) includes a first communication circuit (14), a second communication circuit (15), a third communication circuit (16), and a first switching section (17). , has A first switching unit (17) switches so that data communication is performed by either one of the first communication circuit (14) and the second communication circuit (15). A second communication device (2; 2B; 2C) includes a fourth communication circuit (24), a fifth communication circuit (25), a sixth communication circuit (26), a second switching section (27), a detection and a part (31). A fourth communication circuit (24) communicates with the first communication circuit (14) in a first communication scheme. A fifth communication circuit (25) communicates with the second communication circuit (15) by a second communication method different from the first communication method. A sixth communication circuit (26) communicates with the third communication circuit (16) in at least a third communication scheme different from the first communication scheme. A second switching unit (27) switches so as to perform data communication by either one of the fourth communication circuit (24) and the fifth communication circuit (25). A detection unit (31) detects communication between a first communication circuit (14) and a fourth communication circuit (24) and communication between a second communication circuit (15) and a fifth communication circuit (25). Decrease in communication quality is detected from the value indicating communication quality. When data communication is performed by the first communication circuit (14) and data communication is performed by the fourth communication circuit (24), the second communication circuit (15) and the fifth communication circuit (25) are have completed connection processing and are ready to communicate with each other. A sixth communication circuit (26) transmits a switching signal to the third communication circuit (16) according to the detection result of the detector (31). A second switching unit (27) switches data communication by the fourth communication circuit (24) to data communication by the fifth communication circuit (25) according to the detection result of the detection unit (31). A first switching unit (17) switches data communication by the first communication circuit (14) to data communication by the second communication circuit (15) when the third communication circuit (16) receives the switching signal.

According to this aspect, when switching the communication circuit for performing data communication to the second communication circuit (15) and the fifth communication circuit (25), the second communication circuit (15) and the fifth communication circuit (25) are switched. ) is ready for communication. Therefore, communication can be started simply by switching the communication circuit that performs data communication to the second communication circuit (15) and the fifth communication circuit (25), thereby maintaining communication quality and making communication less likely to be interrupted. can do.

In the communication system (10C) according to the second aspect, in the first aspect, the first communication device (1C) has a plurality of second communication circuits (15). The second communication device (2C) has a plurality of fifth communication circuits (25). The plurality of second communication circuits (15) and the plurality of fifth communication circuits (25) are in one-to-one correspondence. Each of the plurality of second communication circuits (15) communicates with a corresponding fifth communication circuit (25) among the plurality of fifth communication circuits (25).

According to this aspect, it is possible to secure a plurality of sets of switching (backup) communication circuits, so that it is possible to further prevent communication from being interrupted.

In the communication system (10C) according to the third aspect, in the second aspect, the second switching unit (27) switches between the fifth communication circuit (25) and the fifth communication circuit (25) having the highest communication quality value. Switch to data communication by the communication circuit (25).

According to this aspect, it is possible to improve the communication quality of communication between the first communication device (1) and the second communication device (2).

In the communication system (10; 10A; 10B; 10C) according to the fourth aspect, in any one of the first to third aspects, between the first communication circuit (14) and the fourth communication circuit (15) and communication between the second communication circuit (15) and the fifth communication circuit (25) are equal to or greater than a predetermined threshold value, the communication circuit for performing the data communication is selected. .

According to this aspect, communication can be made less likely to be interrupted while maintaining communication quality.

In the communication system (10A) according to the fifth aspect, in any one of the first to fourth aspects, the first communication device (1A) includes a second detection unit (33) as a detection unit (31) and It further has a first detection section (32) for detecting deterioration of the communication quality. A third communication circuit (16) transmits a first switching signal different from the second switching signal as a switching signal to a sixth communication circuit (26) according to the detection result of the first detector (32). A first switching unit (17) switches data communication by the first communication circuit (14) to data communication by the second communication circuit (15) according to the detection result of the first detection unit (32). A second switching unit (27) switches data communication by the fourth communication circuit (24) to data communication by the fifth communication circuit (25) when the sixth communication circuit (26) receives the first switching signal.

According to this aspect, it is possible to deal with the communication situation on the side of the first communication device (1), thereby making it more difficult for the communication to be interrupted.

In the communication system (10B) according to the sixth aspect, in any one of the first to fifth aspects, the second communication circuit (15) and the third communication circuit (16) are shared, and the fifth communication The circuit (25) and the sixth communication circuit (26) are shared.

According to this aspect, it is possible to reduce the size of the first communication device (1) and the second communication device (2).

A communication device (1A) according to a seventh aspect is a communication device (1A) configured to communicate with a counterpart communication device (2). A communication device (1A) has a first communication circuit (14), a second communication circuit (15), a switching section (17), and a detection section (32). The second communication circuit (15) uses a different communication method from the first communication circuit (14). A switching unit (17) switches so that data communication is performed by either one of the first communication circuit (14) and the second communication circuit (15). A detector (32) detects deterioration of communication quality from values indicating communication quality of the first communication circuit (14) and the second communication circuit (15). In the communication device (1A), when data communication is performed by the first communication circuit (14), the second communication circuit (15 ) maintains the state in which the predetermined connection processing has been completed. In the communication device (1A), the second communication circuit (15) transmits a switching signal to the counterpart communication device (2) when the detection unit (32) detects deterioration of the communication quality of the first communication circuit (14). At the same time, the switching unit (17) switches data communication by the first communication circuit (14) to data communication by the second communication circuit (15).

According to this aspect, when switching the communication circuit for performing data communication to the second communication circuit (15), the second communication circuit (15) is in a communicable state. Therefore, communication can be started simply by switching the communication circuit that performs data communication to the second communication circuit (15), thereby maintaining communication quality and making communication less likely to be interrupted.

In the communication device (1A) according to the eighth aspect, in the seventh aspect, the value indicating communication quality includes at least RSSI and data rate. A detector (32) detects deterioration of communication quality when the RSSI is equal to or greater than the first threshold and the data rate is equal to or less than the second threshold.

According to this aspect, the detector (32) can detect deterioration of communication quality based on at least RSSI and data rate.

A communication device (1C) according to a ninth aspect has a plurality of second communication circuits (15) in the seventh or eighth aspect. A switching unit (17) switches to perform data communication with a second communication circuit (15) having the best value indicating communication quality among a plurality of second communication circuits (15).

According to this aspect, it is possible to secure a plurality of sets of switching (backup) communication circuits, so that it is possible to further prevent communication from being interrupted. Also, the communication quality of communication between the communication device (1C) and the counterpart communication device (2) can be improved.

A communication device (1; 1A; 1C) according to a tenth aspect is characterized in that, in any one of the seventh to ninth aspects, the communication system of the first communication circuit (14) and the second communication circuit (15) is It further comprises a different third communication circuit (16). The third communication circuit (16) transmits a switching signal to the counterpart communication device (2) instead of the second communication circuit (15).

According to this aspect, the switching signal can be transmitted to the counterpart communication device (2) by the third communication circuit (16).

1, 1A, 1B, 1C First communication devices 2, 2B, 2C Second communication devices 10, 10A, 10B, 10C Communication system 14 First communication circuit 15 Second communication circuit 16 Third communication circuit 17 First switching unit 24 Fourth communication circuit 25 Fifth communication circuit 26 Sixth communication circuit 27 Second switching unit 31 Detection unit 32 First detection unit 33 Second detection unit (detection unit)

Claims (10)

a first communication device;
A second communication device that communicates with the first communication device,
The first communication device is
a first communication circuit;
a second communication circuit;
a third communication circuit;
a first switching unit that switches so as to perform data communication on either the first communication circuit or the second communication circuit;
The second communication device is
a fourth communication circuit that communicates with the first communication circuit in a first communication method;
a fifth communication circuit communicating with the second communication circuit in a second communication method different from the first communication method;
a sixth communication circuit that communicates with the third communication circuit by a third communication method different from at least the first communication method;
a second switching unit that switches so as to perform data communication by one of the fourth communication circuit and the fifth communication circuit;
detection for detecting deterioration in communication quality from values indicating communication quality of communication between the first communication circuit and the fourth communication circuit and communication between the second communication circuit and the fifth communication circuit; and
When data communication is performed by the first communication circuit and data communication is performed by the fourth communication circuit, the second communication circuit and the fifth communication circuit complete predetermined connection processing and in a state of communication,
The sixth communication circuit transmits a switching signal to the third communication circuit according to the detection result of the detection unit,
The second switching unit switches data communication by the fourth communication circuit to data communication by the fifth communication circuit according to the detection result of the detection unit,
The first switching unit switches data communication by the first communication circuit to data communication by the second communication circuit when the third communication circuit receives the switching signal ,
The first communication device further includes a first detection unit that detects deterioration of the communication quality, unlike the second detection unit as the detection unit,
The third communication circuit transmits a first switching signal different from the second switching signal as the switching signal to the sixth communication circuit according to the detection result of the first detection unit,
The first switching unit switches the data communication by the first communication circuit to the data communication by the second communication circuit according to the detection result of the first detection unit,
The second switching unit switches the data communication by the fourth communication circuit to the data communication by the fifth communication circuit when the sixth communication circuit receives the first switching signal,
The first switching signal and the second switching signal are different signals ,
Communications system. The first communication device has a plurality of the second communication circuits,
The second communication device has a plurality of the fifth communication circuits,
The plurality of second communication circuits and the plurality of fifth communication circuits correspond one-to-one,
each of the plurality of second communication circuits communicates with a corresponding fifth communication circuit among the plurality of fifth communication circuits;
A communication system according to claim 1. The second switching unit switches to data communication by a fifth communication circuit having the best value indicating the communication quality among the plurality of fifth communication circuits.
A communication system according to claim 2. A value indicating the communication quality of communication between the first communication circuit and the fourth communication circuit or a value indicating the communication quality of communication between the second communication circuit and the fifth communication circuit is predetermined A communication circuit that performs data communication is selected so that the threshold of
A communication system according to any one of claims 1 to 3. a timing at which the first switching unit switches the data communication through the first communication circuit to the data communication through the second communication circuit; and a timing at which the second switching unit switches the data communication through the fourth communication circuit to the fifth communication. synchronizing the timing of switching to the data communication by the circuit;
A communication system according to any one of claims 1 to 4. The second communication circuit and the third communication circuit are shared, and the fifth communication circuit and the sixth communication circuit are shared,
A communication system according to any one of claims 1-5. A communication device configured to communicate with a counterpart communication device,
a first communication circuit;
a second communication circuit;
a first switching unit that switches so as to perform data communication by one of the first communication circuit and the second communication circuit;
a first detection unit that detects deterioration in communication quality from values indicating communication quality of the first communication circuit and the second communication circuit;
has
The counterparty communication device,
a counterparty first communication circuit that communicates with the first communication circuit in a first communication method;
a counterpart second communication circuit communicating with the second communication circuit in a second communication method different from the first communication method;
a second switching unit that switches so as to perform data communication by one of the counterparty first communication circuit and the counterparty second communication circuit;
a second detection unit that detects deterioration in communication quality from values indicating the communication quality of the counterparty first communication circuit and the counterparty second communication circuit;
has
When performing data communication in the first communication circuit,
when the first detection unit does not detect deterioration of the communication quality of the first communication circuit, the second communication circuit maintains a state in which a predetermined connection process is completed;
When the first detection unit detects deterioration of the communication quality of the first communication circuit, the second communication circuit transmits a first switching signal to the counterparty second communication circuit , and the first switching unit switching data communication by the first communication circuit to data communication by the second communication circuit ;
When data communication is performed on the first communication circuit of the other party,
when the second detection unit does not detect deterioration of the communication quality of the first communication circuit of the other party, the second communication circuit of the other party maintains a state in which predetermined connection processing is completed;
When the second detection unit detects the deterioration of the communication quality of the first communication circuit of the other party, the second communication circuit of the other party transmits a second switching signal to the second communication circuit, and the second switching unit switches data communication by the first communication circuit of the other party to data communication by the second communication circuit of the other party,
The first switching unit switches the data communication by the first communication circuit to the data communication by the second communication circuit when the second communication circuit receives the second switching signal,
wherein, when the counterparty second communication circuit receives the first switching signal, the second switching unit switches the data communication by the counterparty first communication circuit to the data communication by the counterparty second communication circuit;
The first switching signal and the second switching signal are different signals ,
Communication device. The value indicating the communication quality includes at least RSSI and data rate,
The first detection unit detects deterioration of communication quality when the RSSI is equal to or greater than a first threshold and the data rate is equal to or less than a second threshold.
8. A communication device according to claim 7. Having a plurality of second communication circuits,
The first switching unit switches to perform data communication with a second communication circuit having the best value indicating the communication quality among the plurality of second communication circuits.
A communication device according to claim 7 or 8. further comprising a third communication circuit having a communication method different from that of the first communication circuit and the second communication circuit;
wherein the third communication circuit transmits the first switching signal to the counterpart communication device instead of the second communication circuit;
The communication device according to any one of claims 7-9.

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