JP7659446B2 - Radio systems and radios - Google Patents

Description

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

A wireless system has been proposed that includes a wireless slave device installed in a home equipment device, a center side device that collects various data from the home equipment device, and a wireless master device that communicates with the wireless slave device via a wireless line to collect various data from the home equipment device and also communicates with the center side device via the line (see, for example, Patent Document 1). In this wireless system, the wireless master device has a carrier busy count unit that periodically checks the radio wave conditions. Therefore, when a busy state is detected on the frequency used for communication, the wireless master device reports this information to the center side device.

JP 2004-180105 A

Here, the inventors are considering changing the frequency used for wireless communication (changing the communication channel) when a busy state (radio wave interference state) is detected, as in the wireless system described in Patent Document 1.

However, when changing the communication channel, it is necessary to change it quickly for all of the multiple radios in the network. In other words, if it takes a long time to change the communication channel, radios that have changed the communication channel will be mixed with radios that have not changed the channel until the change is complete, which may cause communication problems within the network.

Therefore, it is conceivable to equip each radio with a separate device capable of communicating in order to change the communication channel. For example, if communication between radio devices under normal circumstances is carried out in a specific frequency band, and all of the multiple radio devices are equipped with a separate device that communicates in a frequency band separate from the specific frequency band, then when radio interference occurs, the separate device can be used to spread communication channel change information throughout the network, making it possible to change the communication channel throughout the entire network.

However, in this case, it would be necessary to install additional equipment, which would lead to a more complicated configuration.

The present invention was made to solve these problems, and its purpose is to provide a wireless system and wireless device that can reduce the complexity of the configuration and change the communication channel of the entire network more quickly.

The wireless system according to the present invention is a wireless system in which information can be transmitted and received within a network configured with a plurality of wireless devices, and a specific wireless device among the plurality of wireless devices can transmit and receive information with a center side, and non-specific wireless devices among the plurality of wireless devices other than the specific wireless device transmit and receive information with the specific wireless device via or without passing through other non-specific wireless devices, and transmit and receive information with the center side through the specific wireless device, and the wireless device has a first communication unit that transmits first information to the surroundings, and when the first information is received from another wireless device and there is information to be transmitted to the sender of the first information, the first communication unit transmits and receives the ... The device includes a second communication unit that transmits second information by specifying a source of information and thereafter transmits and receives information with the source of the first information, an interference determination unit that determines whether the device itself is in a state of radio wave interference based on the radio wave strength of the channel currently in use, and a third communication unit that, when the interference determination unit determines that the device itself is in a state of radio wave interference, transmits channel switching information in addition to the source of the first information or in place of the second information when the device receives the first information from another wireless device, rather than only specifying the source of the first information. The third communication unit includes a channel switching unit that switches the device's own channel after transmitting the channel switching information by the third communication unit.

The radio device according to the present invention includes a first communication unit that transmits first information to the surroundings, a second communication unit that, when receiving the first information from another radio device, specifies the source of the first information and transmits second information when there is information to be transmitted to the source of the first information, and thereafter transmits and receives information with the source of the first information, an interference determination unit that determines whether the radio device itself is in a state of radio interference based on the radio wave strength of the channel currently in use, a third communication unit that, when the interference determination unit determines that the radio device itself is in a state of radio interference, transmits channel switching information to the second information or in place of the second information when the radio device receives the first information from another radio device, rather than only specifying the source of the first information, and a channel switching unit that switches the channel of the radio device itself after transmitting the channel switching information by the third communication unit.

According to the present invention, information to be transmitted is transmitted and received through transmission and reception of first information and second information, and if it is determined that radio wave interference exists, when the first information is received from another wireless device, channel switching information is transmitted in addition to or instead of the second information. This means that channel switching information is transmitted in the same manner as when normal information is transmitted and received, and it is possible to prevent the configuration from becoming complicated as in the case where a separate device is provided.

In addition, when transmitting and receiving the first information and the second information, the second information is normally transmitted by specifying the source of the first information, but when there is radio interference, the channel switching information is transmitted in addition to or instead of the second information without specifying the source of the first information. Therefore, the channel switching information is received not only by the radio device that sent the first information, but also by other radio devices in the vicinity. This allows the channels of the surrounding radio devices to be switched simultaneously, making it possible to change the communication channel of the entire network more quickly.

This makes it possible to provide a wireless system and wireless device that can reduce the complexity of the configuration and change the communication channel of the entire network more quickly.

1 is a configuration diagram showing a wireless system according to an embodiment of the present invention. 2 is a functional block diagram showing the configuration of each of the multiple wireless devices shown in FIG. 1 . 4 is a conceptual diagram showing how information is transmitted and received by a first communication unit. FIG. 4 is a conceptual diagram showing transmission and reception of information by a first communication unit and a second communication unit. FIG. FIG. 1 is a conceptual diagram showing how information is transmitted and received in a radio wave interference state. 1 is a conceptual diagram showing how a wireless device that has received channel switching information from a wireless device in a radio interference state transmits and receives information; 11 is a conceptual diagram showing transmission and reception of information when a second determination unit determines a radio wave interference state. FIG. FIG. 11 is a conceptual diagram showing channel switching by a radio device constituting a wireless system according to a second embodiment.

The present invention will be described below in accordance with a preferred embodiment. Note that the present invention is not limited to the embodiment described below, and can be modified as appropriate without departing from the spirit of the present invention. In addition, in the embodiment described below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are used as appropriate for the details of the omitted technologies, within the scope of not causing any inconsistencies with the contents described below.

Figure 1 is a configuration diagram showing a wireless system according to an embodiment of the present invention. As shown in Figure 1, the wireless system 1 according to this embodiment is configured to include multiple connection devices M, multiple wireless devices WD, and a center side device CA.

The multiple connection devices M are gas meters, gas alarm devices, etc., and are connected to each wireless device WD, for example, by wires. These connection devices M transmit information to the center side device CA via the multiple wireless devices WD, and receive information from the center side device CA via the multiple wireless devices WD. Information transmitted from the connection devices M to the center side device CA includes, for example, gas meter reading information and fault information, and gas alarm alarm warning information and fault information. Information received from the center side device CA includes, for example, information to open and close the gas meter shutoff valve, and audio information output from a gas alarm.

The multiple radio devices WD are capable of wirelessly transmitting and receiving information to and from other radio devices WD within a network configured with multiple radio devices WD. The multiple radio devices WD include a specific radio device WD1. The specific radio device WD1 is capable of transmitting and receiving information to and from a center side device CA via a line in accordance with a communication standard such as LTE (Long Term Evolution).

Of the multiple radios WD, the non-specific radios WD2, excluding the specific radio WD1, are capable of transmitting and receiving information to and from the center side device CA via the specific radio WD1. To explain in more detail, for example, the first radio WD21 transmits and receives information to and from the center side device CA only through the specific radio WD1 without having any other non-specific radios WD2. The second radio WD22 transmits and receives information to and from the specific radio WD1 via the first radio WD21, and transmits and receives information to and from the center side device CA through the specific radio WD1. Furthermore, the third radio WD23 transmits and receives information to and from the specific radio WD1 via the first radio WD21 and the second radio WD22, and transmits and receives information to and from the center side device CA through the specific radio WD1.

Figure 2 is a functional block diagram showing the configuration of each of the multiple wireless devices WD shown in Figure 1. As shown in Figure 2, each wireless device WD includes an input unit 10, an output unit 20, a communication unit 30, a first determination unit (interference determination unit) 40, a second determination unit (second interference determination unit) 50, and a channel switching unit 60.

The input unit 10 inputs information to be transmitted to the center side device CA (see FIG. 1) from the connected connection device M (see FIG. 1). When information is input by the input unit 10, the wireless device WD determines that there is information that needs to be transmitted. Furthermore, when information that needs to be transmitted is sent from another wireless device WD, the wireless device WD also determines that there is information that needs to be transmitted.

The output unit 20 outputs the information transmitted from the center side device CA to the connected connection device M. The connection device M receives information from the output unit 20 of the wireless device WD and executes control according to the received information.

The communication unit 30 is a functional unit that performs wireless communication with other wireless devices WD. This communication unit 30 includes a first communication unit 31, a second communication unit 32, a third communication unit 33, a fourth communication unit 34, and a fifth communication unit 35.

The first communication unit 31 transmits a "RIT Data Request" (first information) to the surroundings. This "RIT Data Request" is beacon information that allows the wireless device WD to inform other wireless devices WD of its presence. When the first communication unit 31 of the wireless device WD transmits a "RIT Data Request", the wireless device WD enters a short-time reception state (short reception state). Furthermore, when the wireless device WD wirelessly receives a "RIT Data Request" from another wireless device WD, it can recognize that it is able to communicate with the other wireless device WD.

Figure 3 is a conceptual diagram showing how information is sent and received by the first communication unit 31. In Figure 3, an example is explained using a radio A, which is one of the multiple radios WD, and a radio B, which is the other. The first communication unit 31 of radio A (see Figure 2) transmits a "RIT Data Request" at a specific period. Also, as shown in Figure 3, the first communication unit 31 of radio A enters a short reception state after transmitting a "RIT Data Request". This short reception state is a state in which the first communication unit 31 waits for a reply to the "RIT Data Request" ("RIT Data Response" described below). In this way, radio A periodically transmits a "RIT Data Request" using the first communication unit 31, and enters a short reception state each time it transmits.

The same is true for radio B. That is, radio B periodically transmits "RIT Data Request" using the first communication unit 31, and enters a short reception state each time it transmits.

Referring again to FIG. 2. When the second communication unit 32 receives a "RIT Data Request" from another wireless device WD, it replies if it has information that needs to be transmitted. At this time, the second communication unit 32 specifies the sender of the "RIT Data Request" and replies with a "RIT Data Response" (second information) as an SREQ (transmission request). In particular, when the second communication unit 32 receives a "RIT Data Request" from another wireless device WD while it has information that needs to be transmitted, it replies quickly so that the "RIT Data Response" arrives while the other wireless device WD is in a short reception state.

Figure 4 is a conceptual diagram showing how information is sent and received by the first communication unit 31 and the second communication unit 32. In Figure 4, radio A and radio B are used as examples. As explained with reference to Figure 3, radio A and B periodically transmit "RIT Data Requests" and enter a short reception state after each transmission. Now, assume that radio B has information that needs to be transmitted to radio A. In this case, the first communication unit 31 (see Figure 2) of radio B stops the periodic transmission of "RIT Data Requests" and enters a reception state waiting for a "RIT Data Request" from radio A.

Next, when wireless device B receives the "RIT Data Request" from wireless device A, it quickly transmits a "RIT Data Response" to wireless device A (while wireless device A is in a short reception state). Then, wireless device A receives the "RIT Data Response" from wireless device B.

In this way, when wireless device A is in a short reception state, a "RIT Data Response" is sent from wireless device B and received by wireless device A, establishing one-to-one communication between the two devices (i.e., unicast state).

Refer to FIG. 2 again. As shown in FIG. 2, the second communication unit 32 includes first to third functional units 32a to 32c. As described above, once one-to-one communication is established, the second communication unit 32 transmits and receives information between the two wireless devices WD using the first to third functional units 32a to 32c.

When the first functional unit 32a receives a "RIT Data Response" from another radio device WD, it transmits a "RACK" (request information) to the other radio device WD that sent the "RIT Data Response" to request information to be transmitted.

When the second functional unit 32b receives a "RACK" from another radio device WD, it transmits "DATA", which is information that needs to be transmitted, to the other radio device WD that sent the "RACK".

When the third functional unit 32c receives "DATA (information to be transmitted)" from another radio device WD, it transmits "DACK" (acknowledgement information) to the other radio device WD that is the sender of the information to be transmitted.

Refer to FIG. 4 again. As described above, when radio A is in a short reception state, radio B transmits a "RIT Data Response" which is received by radio A, establishing one-to-one communication between the two. After that, the first functional unit 32a of radio A designates radio B and transmits "RACK." When the second functional unit 32b of radio B receives "RACK," it designates radio A and transmits "DATA." Next, when the third functional unit 32c of radio A receives "DATA," it designates radio B and transmits "DACK."

As shown in FIG. 4, the transmission-required information of radio B is transmitted to radio A. Radio A then transmits the transmission-required information to the specific radio WD1 via another non-specific radio WD2, etc. When the specific radio WD1 receives the transmission-required information, it transmits the transmission-required information to the center side device CA via a base station, etc.

Referring again to FIG. 2. The first determination unit 40 determines whether or not it is in an interference state based on the radio wave strength of the channel currently in use (performs what is known as carrier sense). Here, the radio device WD described above may be in a radio wave interference state in which it is difficult to send and receive information depending on the surrounding environment. For this reason, the first determination unit 40 determines whether or not it is in a radio wave interference state based on whether or not the surrounding radio wave strength is equal to or greater than a predetermined value.

Here, it is preferable that the first determination unit 40 makes a determination when transmitting information. Specifically, when the first communication unit 31 transmits a "RIT Data Request", the wireless device WD determines whether there is radio interference based on the radio wave strength of the channel currently in use. The first determination unit 40 also determines whether there is radio wave interference when the first function unit 32a to the third function unit 32c transmit information.

If the first determination unit 40 determines that radio wave interference exists, information transmission by the first communication unit 31 and the first function unit 32a to the third function unit 32c is prohibited.

In such a radio interference state, it is necessary to switch the channel currently in use, and it is preferable to switch channels quickly throughout the entire network. However, providing dedicated equipment for switching would lead to a complex configuration. Therefore, the wireless system 1 according to this embodiment is provided with a third communication unit 33 and a fourth communication unit 34 to execute channel switching using the information transmission and reception method shown in FIG. 4.

The third communication unit 33 shown in FIG. 2 transmits channel switching information when the first determination unit 40 determines that the wireless device WD is in a radio interference state, for example when the radio interference happens to weaken and the third communication unit 33 is able to receive a "RIT Data Request" from another wireless device WD. At this time, the third communication unit 33 adds the channel switching information to the "RIT Data Response" and transmits it to the surroundings without designating the other party as the sender.

To explain in more detail, if there is no radio interference, the second communication unit 32 designates the other party as the sender of the "RIT Data Request" and transmits a "RIT Data Response." In contrast, if there is radio interference, the third communication unit 33 adds channel switching information to the "RIT Data Response" without designating the other party as the sender and transmits it to the surrounding area.

This allows the channel switching information to be sent to other wireless devices WD located within a communication distance of the wireless device WD itself (i.e., to devices other than the sender of the "RIT Data Request").

Figure 5 is a conceptual diagram showing how information is sent and received in a radio interference state. In Figure 5, radio devices A and B are used as examples. First, assume that the first communication unit 31 (see Figure 2) of radio device A periodically transmits a "RIT Data Request" and the first determination unit 40 (see Figure 2) of radio device B determines that it is in a radio interference state.

When there is radio interference, radio B generally cannot receive a "RIT Data Request" from radio A. However, there are times when the radio interference weakens temporarily, at which point radio B can receive a "RIT Data Request" from radio A.

When the first determination unit 40 determines that radio interference exists and receives a "RIT Data Request" from wireless device A, the third communication unit 33 of wireless device B (see FIG. 2) adds channel switching information to the "RIT Data Response" and transmits it in time for wireless device A's short reception state. In particular, the third communication unit 33 does not perform so-called unicasting, but transmits the channel switching information to the surroundings by broadcast or multicast. As a result, the channel switching information is received by many surrounding wireless devices WD.

In this case, the first functional unit 32a to the third functional unit 32c (see FIG. 2) will not transmit or receive information. However, if the radio B has information that needs to be transmitted, the first functional unit 32a to the third functional unit 32c may communicate.

Referring again to FIG. 2. The channel switching unit 60 switches the channel of the wireless device WD after the third communication unit 33 transmits the channel switching information. In this embodiment, for example, communication is possible through two communication channels, and the channel switching unit 60 switches from the channel currently in use to the other channel.

Furthermore, the wireless device WD according to this embodiment is configured to quickly switch channels within the network using the fourth communication unit 34. When the fourth communication unit 34 receives channel switching information from another wireless device WD, it transmits the channel switching information to the surroundings. In this embodiment, it is assumed that the fourth communication unit 34 transmits channel switching information in conjunction with the transmission of "DATA."

Figure 6 is a conceptual diagram showing how a radio device WD transmits and receives information after receiving channel switching information from another radio device WD that is in a radio interference state. In Figure 6, an example is explained using radio device A that received channel switching information and another radio device C.

First, assume that the radio A receives channel switching information from the radio B as described with reference to FIG. 5. Also assume that the radio A has the transmission-required information. In this case, the radio A replies with a "RIT Data Response" to the "RIT Data Request" from the radio C. Next, when the radio A receives a "RACK" from the radio C, it replies with the transmission-required information (DATA). At this time, the fourth communication unit 34 (see FIG. 2) of the radio A adds the channel switching information to the transmission-required information and transmits it. In addition, the fourth communication unit 34 transmits this transmission-required information to the surroundings by broadcast or multicast. As a result, the channel switching information is also received by the surrounding radios WD other than the radio C. Note that the transmission-required information is not necessary for the surrounding radios WD other than the radio C, so it may be discarded, but considering the instability of communication due to channel switching, it may be transmitted to other radios WD without discarding it. In addition, when wireless device C receives transmission-required information and channel switching information, it executes processing on the upper wireless device WD (center wireless device WD) and the like, in the same way as wireless device A shown in FIG. 6.

Next, wireless device A adds channel switching information to the transmission-required information and transmits it, and then receives "DACK" from wireless device C. When the channel switching unit 60 of wireless device A confirms receipt of "DACK", it switches the channel.

In the example shown in FIG. 6, channel switching information is transmitted together with "DATA", but this is not limited to this. For example, when a "RIT Data Request" is received from another wireless device WD (not limited to wireless device C), the channel switching information may be broadcast or multicast transmitted together with a "RIT Data Response". This is possible because the channel switching information can be spread to the surroundings even if the wireless device WD does not have information to be transmitted.

In addition, in the example shown in FIG. 6, the information shown in FIG. 6 is transmitted and received when wireless device A has channel switching information and transmission-required information, but this is not limited to the above, and wireless device A may transmit and receive the information shown in FIG. 6 when it has channel switching information but does not have transmission-required information. In this case, wireless device A will broadcast or multicast only the channel switching information without transmitting "DATA".

Referring again to FIG. 2. Furthermore, the wireless system 1 according to this embodiment not only has the wireless device WD determine its own radio interference state by the first determination unit 40, but also has a second determination unit 50, which can determine whether another wireless device WD is in a radio interference state.

More specifically, the second determination unit 50 determines that the other wireless device WD is in a state of radio interference when it receives a "RIT Data Response" from the other wireless device WD and transmits a "RACK", but is unable to receive "DATA" (when there is no reply).

The wireless device WD according to this embodiment also includes a fifth communication unit 35, and when the second determination unit 50 determines that there is radio interference from another wireless device WD, the fifth communication unit 35 transmits channel switching information to the surroundings. At this time, when the fifth communication unit 35 receives a "RIT Data Request" from a wireless device WD other than itself, it adds the channel switching information to the "RIT Data Response" and transmits the channel switching information to the surroundings by broadcast transmission or multicast transmission.

Figure 7 is a conceptual diagram showing how information is sent and received when the second determination unit 50 determines the radio interference state. In Figure 7, wireless devices A and B are used as an example for explanation.

First, wireless device A periodically transmits a "RIT Data Request" and enters a short reception state each time it transmits. Now, assume that wireless device B has transmission information to send to wireless device A. In this case, when wireless device B receives a "RIT Data Request" from wireless device A, it transmits a "RIT Data Response" while wireless device A is in a short reception state. After that, wireless device A transmits a "RACK" to wireless device B.

Next, wireless device B receives "RACK" and transmits "DATA" to wireless device A, but assume that "DATA" is not received by wireless device A. At this time, the second determination unit 50 of wireless device A determines that wireless device B is in a radio interference state.

After that, suppose that a "RIT Data Request" is received from a wireless device WD other than itself (it could be wireless device B). As a result, the fifth communication unit 35 of wireless device A adds channel switching information to the "RIT Data Response" and transmits the channel switching information to the surroundings by broadcasting or multicasting. This allows wireless device A to determine the radio wave interference state of wireless device B and transmit channel switching information to the surroundings.

Next, the operation of the wireless system 1 according to this embodiment will be described. First, each wireless device WD shown in FIG. 1 periodically transmits a "RIT Data Request" as shown in FIG. 3. For example, assume that a gas alarm device (connected device M) connected to the third wireless device WD23 detects a gas leak and issues an alarm. In this case, the input unit 10 of the third wireless device WD23 inputs alarm information as information to be transmitted. Then, as shown in FIG. 4, the third wireless device WD23 enters a receiving state in which it waits for a "RIT Data Request" from the second wireless device WD22, which is a higher-level device, in order to transmit information to be transmitted to the center-side device CA.

Next, when the third radio WD23 receives a "RIT Data Request" from the second radio WD22, the first communication unit 31 of the third radio WD23 replies with a "RIT Data Response" in time for the second radio WD22 to enter a short reception state. After that, the first function unit 32a of the second radio WD22 transmits "RACK" specifying the third radio WD23, and the second function unit 32b of the third radio WD23 transmits "DATA" specifying the second radio WD22. Next, the third function unit 32c of the second radio WD22 transmits "DACK" specifying the third radio WD23. As a result, the alarm information of the third radio WD23 ("DATA" which is information to be transmitted) is transmitted to the second radio WD22.

After that, the second radio WD22 communicates in the same way as the first radio WD21 and transmits the alarm information to the first radio WD21, and the first radio WD21 communicates in the same way as the specific radio WD1 and transmits the alarm information to the specific radio WD1. The specific radio WD1 transmits the alarm information to the center side device CA via a base station or the like in accordance with a communication standard such as LTE.

Furthermore, the center side device CA that receives such alarm information transmits shutoff information ("DATA", which is information that needs to be transmitted) to a specific radio WD1 via a base station or the like in order to close the shutoff valve of, for example, a gas meter (connected device M) connected to the second radio WD22.

The specific wireless device WD1 transmits the shutoff information to the second wireless device WD22 via the first wireless device WD21, as described above. The second wireless device WD22, which receives the shutoff information, transmits the shutoff information to the gas meter via the output unit 20. This causes the gas meter to close its own shutoff valve.

In the process of transmitting and receiving such information, for example, suppose that the second radio device WD22 transmits a "RACK" to the first radio device WD21 but does not return a "DATA." In this case, the second determination unit 50 of the second radio device WD22 determines that the first radio device WD21, which is the other party in the unicast communication, is in a state of radio interference, as shown in FIG. 7.

The second radio WD22 then receives a "RIT Data Request" from another radio WD. At this time, the fifth communication unit 35 of the second radio WD22 adds channel switching information to the "RIT Data Response" and transmits the channel switching information to the surroundings by broadcasting or multicasting. As a result, the channel switching information is transmitted not only to the first radio WD21, with which the second radio WD22 was communicating, but also to the surrounding radios WD. The channel switching unit 60 of the second radio WD22 switches the channel after transmitting the channel switching information.

Furthermore, apart from the above-mentioned transmission and reception process of the required transmission information, the first determination unit 40 of each radio device WD determines whether it is in a radio interference state. Here, it is assumed that the first determination unit 40 of the second radio device WD22 determines that it is in a radio interference state. In this case, when the radio interference of the second radio device WD22 temporarily weakens and it is able to receive a "RIT Data Request" from another radio device WD, it adds channel switching information to the "RIT Data Response" and transmits the channel switching information to the surroundings by broadcasting or multicasting. As a result, for example, the first radio device WD21 and the third radio device WD23 that are present near the second radio device WD22 receive the channel switching information. Note that the channel switching unit 60 of the second radio device WD22 switches the channel after transmitting the channel switching information.

The first radio WD21 that has received the channel switching information enters a state of holding the channel switching information, and when it receives transmission-required information from another radio WD or inputs transmission-required information from the connected device M via the input unit 10, it transmits and receives the information shown in FIG. 6. That is, the first radio WD21 receives, for example, a "RIT Data Request" from a specific radio WD1 and replies with a "RIT Data Response". Next, when it receives a "RACK" from the specific radio WD1, the fourth communication unit 34 adds the channel switching information to the "DATA" and performs broadcast communication or multicast communication. As a result, the channel switching information is received not only by the specific radio WD1 but also by other surrounding radios WD. The channel switching unit 60 of the first radio WD21 switches the channel after transmitting the channel switching information.

In this way, the wireless system 1 and wireless device WD according to this embodiment transmit and receive information that needs to be transmitted through the transmission and reception of "RIT Data Request" and "RIT Data Response". If it is determined that there is radio interference, when a "RIT Data Request" is received from another wireless device WD, channel switching information is transmitted in addition to or instead of the "RIT Data Response". This means that channel switching information is transmitted in the same way as when normal information is transmitted and received, and it is possible to prevent the configuration from becoming complicated as in the case where a separate device is provided.

In addition, when transmitting and receiving a "RIT Data Request" and a "RIT Data Response", the "RIT Data Response" is normally sent specifying the sender of the "RIT Data Request", but when there is radio interference, the "RIT Data Response" is sent in addition to the channel switching information without specifying the sender of the "RIT Data Request". As a result, channel switching information is received not only from the radio WD that sent the "RIT Data Request", but also from other radios WD in the vicinity. This makes it possible to switch channels for the surrounding radios WD all at once, making it possible to change the communication channel for the entire network more quickly.

Therefore, it is possible to provide a wireless system 1 that can reduce the complexity of the configuration and change the communication channel of the entire network more quickly.

In addition, when a radio device WD receives channel switching information from another radio device WD, it transmits the channel switching information to the surrounding area and switches the channel of its own radio device WD after transmission. Therefore, channel switching information can be transmitted to the surrounding area not only for radio devices WD in a state of radio interference, but also for radio devices WD that received channel switching information from that radio device WD, making it possible to change the communication channel of the entire network even more quickly.

In addition, when a "RIT Data Response" is received from another radio WD, if a "RACK" is sent to the other radio WD requesting a reply of the required transmission information (DATA) but the other radio WD does not reply with the required transmission information, the other radio WD determines that it is in a state of radio interference. Therefore, when there is no radio interference, the reception of the "RIT Data Response", the transmission of the "RACK", and the reception of "DATA" should normally be consecutive, but if the other radio WD is unable to receive "DATA", it can be said that the other radio WD has suddenly entered a state of radio interference. Therefore, when it is unable to receive "DATA", it can be determined that the other radio WD is in a state of radio interference, and channel switching information can be transmitted from the radio WD surrounding the radio WD in the state of radio interference.

Next, we will explain the second embodiment of the present invention. The wireless system according to the second embodiment is similar to that of the first embodiment, but some of the processing content is different.

Figure 8 is a conceptual diagram showing channel switching by a radio device WD constituting a wireless system 1 according to the second embodiment. Note that in Figure 8, radio devices A to C, which are one of the multiple radio devices WD, are used as an example for explanation. Radio device B is assumed to be in a state of radio interference. Also, the bars extending from radio devices A to C shown in Figure 8 are filled with white and black, with the white bars indicating the channel before switching and the black bars indicating the channel after switching.

First, it is assumed that the first determination unit 40 of the wireless device B determines that it is in a state of radio interference. As a result, the third communication unit 33 of the wireless device B adds channel switching information to the "RIT Data Response" and transmits it by broadcast or multicast, in the same manner as in the method described with reference to FIG. 5. The wireless device B that transmitted the channel switching information switches the channel.

The fourth communication unit 34 of the wireless device A that receives the channel switching information adds the channel switching information to "DATA" and broadcasts or multicasts it, for example, in the same manner as described with reference to FIG. 6. The wireless device A that transmitted the channel switching information switches channels. Furthermore, in the second embodiment, after the channel switching, the fourth communication unit 34 of the wireless device A broadcasts or multicasts the channel switching information again on the channel after the channel switching. In other words, when the fourth communication unit 34 receives channel switching information from another wireless device WD, it transmits the channel switching information to the surroundings on two channels, one before and one after the channel switching.

As shown in FIG. 8, assume that the channel switching information transmitted on the channel before switching did not reach wireless device C due to an accidental deterioration of the radio wave environment. In this case, since wireless device C has not switched channels, it cannot receive the channel switching information transmitted on the channel after switching, and wireless device C may become isolated without switching channels.

In this embodiment, the third communication unit 33 of the radio B executes a recovery process in which, after switching its own channel by the channel switching unit 60, it transmits channel switching information again on the two channels before and after the channel switching. This makes it possible to transmit channel switching information again on the channel before switching to a radio WD that is in an isolated state without switching channels, such as radio C.

Even if the isolated radio WD is not at a distance from radio B where the channel switching information can reach it directly, as shown in FIG. 8, the channel switching information can be made to reach radio C via radio A. That is, as described above, when the fourth communication unit 34 of radio A receives the channel switching information, it transmits the channel switching information on two channels, one before and one after the switch. Therefore, when the channel switching information is received by the recovery process of radio B, the channel switching information is broadcast or multicast from radio A on the two channels, one before and one after the switch, and the isolated radio C can receive the channel switching information on the channel before the switch.

In this way, in the wireless system 1 according to the second embodiment, for a wireless device WD that is determined by the first determination unit 40 to be in a radio interference state, even after the channel switching information has been broadcast or multicast transmitted to switch channels, the channel switching information is again broadcast or multicast transmitted on the two channels before and after the switch by a recovery process.

Moreover, in the wireless system 1 according to the second embodiment, for a wireless device WD that receives channel switching information, the channel switching information is broadcast or multicast on two channels, one before and one after the switch. Therefore, even if channel switching information is received by the recovery process, the channel switching information is broadcast or multicast on two channels, one before and one after the switch, and the channel switching information is spread on two channels. As a result, the channels are quickly switched for all wireless devices WD in the network to prevent an isolated wireless device WD from occurring.

In this way, the wireless system 1 and wireless device WD according to the second embodiment can achieve the same effects as those of the first embodiment.

Furthermore, according to the second embodiment, the third communication unit 34 executes a recovery process, so that it becomes possible to transmit channel switching information to the surrounding area again to a radio device WD that is isolated because it cannot receive channel switching information, and it becomes possible to more reliably switch communication channels throughout the entire network.

In addition, for a radio WD that has received channel switching information, the fourth communication unit 34 transmits the channel switching information to the surrounding area on two channels, one before and one after the switch. Therefore, even if an isolated radio WD is not close enough to receive the channel switching information through the recovery process, the radio WD that received the channel switching information will relay it, making it possible to switch communication channels even more reliably.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the present invention, and known or well-known technologies may be combined to the extent possible.

For example, in the above embodiment, the channel switching information is added to the "RIT Data Response" or to "DATA" and then transmitted, but it is not limited to being added, and may be transmitted instead of the "RIT Data Response" or "DATA".

In addition, the number of connected devices M connected to the wireless device WD may not be one, but multiple connected devices M may be connected to one wireless device WD. In addition, the wireless device WD and the connected devices M may be connected by wire or wirelessly.

In addition, the first determination unit 40 according to this embodiment may determine that radio wave interference exists when the surrounding radio wave strength for the current channel is equal to or greater than a predetermined value for a predetermined number of consecutive times.

1: Wireless system 10: Input unit 20: Output unit 30: Communication unit 31: First communication unit 32: Second communication unit 32a: First functional unit 32b: Second functional unit 32c: Third functional unit 33: Third communication unit 34: Fourth communication unit 35: Fifth communication unit 40: First determination unit (interference determination unit)
50: Second judgment unit (second interference judgment unit)
60: Channel switching unit CA: Center side device M: Connecting device WD: Wireless device WD1: Specific wireless device WD2: Non-specific wireless device

Claims (6)

A wireless system in which information can be transmitted and received within a network including a plurality of wireless devices, a specific wireless device among the plurality of wireless devices can transmit and receive information to and from a center side, and non-specific wireless devices among the plurality of wireless devices other than the specific wireless device transmit and receive information to and from the specific wireless device via or without passing through other non-specific wireless devices, and transmit and receive information to and from the center side through the specific wireless device,
The radio device includes:
A first communication unit that transmits first information to the surroundings;
a second communication unit that, when receiving the first information from another wireless device, transmits second information by designating the source of the first information when there is information to be transmitted to the source of the first information, and thereafter transmits and receives information to and from the source of the first information;
an interference determination unit that determines whether or not the own station is in a state of radio interference based on the radio wave strength of a channel currently in use;
a third communication unit that, when the interference determination unit has determined that the wireless device itself is in a radio wave interference state and, upon receiving the first information from another wireless device, adds channel switching information to the second information or transmits the channel switching information instead of the second information to surrounding areas, rather than to a specified state of only a transmission source of the first information;
a channel switching unit that switches its own channel after transmitting channel switching information by the third communication unit;
A wireless system comprising: the wireless device further includes a fourth communication unit that transmits channel switching information to surrounding areas when the wireless device receives channel switching information from another wireless device;
The wireless system according to claim 1 , wherein the channel switching unit switches its own channel after transmitting channel switching information by the fourth communication unit. The wireless system according to claim 2 , wherein the third communication unit executes a recovery process of transmitting channel switching information again on two channels before and after the channel switching unit switches its own channel. 4. The wireless system according to claim 2, wherein the fourth communication unit, when receiving channel switching information from another wireless device, transmits the channel switching information to surrounding areas on two channels before and after the channel switching. The radio device includes:
a second interference determination unit that, when receiving the second information from another wireless device, determines that the other wireless device is in a radio interference state when there is no reply of the required transmission information from the other wireless device despite having transmitted request information requesting a reply of the required transmission information to the other wireless device;
a fifth communication unit that, when the second interference determination unit determines that the other wireless device is in a radio wave interference state and receives the first information from the other wireless device, adds channel switching information to the second information and transmits the second information to surrounding areas, rather than to a designated state of only the other wireless device;
The wireless system according to any one of claims 1 to 4, further comprising: A first communication unit that transmits first information to the surroundings;
a second communication unit that, when receiving the first information from another wireless device, transmits second information by designating the source of the first information when there is information to be transmitted to the source of the first information, and thereafter transmits and receives information to and from the source of the first information;
an interference determination unit that determines whether or not the own station is in a state of radio interference based on the radio wave strength of a channel currently in use;
a third communication unit that, when the interference determination unit has determined that the wireless device itself is in a radio wave interference state and, upon receiving the first information from another wireless device, adds channel switching information to the second information or transmits the channel switching information instead of the second information to surrounding areas, rather than to a specified state of only a transmission source of the first information;
a channel switching unit that switches its own channel after transmitting channel switching information by the third communication unit;
A radio device comprising:

Images