JP2023169485A - wireless device - Google Patents

Abstract

To select a communication path through simple processing in a wireless communication system in which a plurality of communication conditions are defined.SOLUTION: A base unit 10 communicates with a slave unit 10 according to an active communication path that is one of a plurality of communication paths formed by relay machines 12-1 to 12-4 and a slave unit 14, and obtains path evaluation information regarding the active communication path on the basis of the wireless communication performed with the relay machine 12-1. The base unit 10 changes the communication path to be the active communication path to another communication path on the basis of the path evaluation information.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to wireless devices, and particularly to processing for changing communication conditions.

There is a wireless communication system in which communication is performed between two wireless devices via a relay device. A wireless communication system includes one or more repeaters, and a communication path is formed from one wireless device to another wireless device. Patent Document 1 below describes a wireless communication system in which transmission of wireless communication data packets between wireless communication terminals is relayed by another wireless communication terminal.

Japanese Patent Application Publication No. 2003-174452

Generally, a wireless communication system including a plurality of repeaters has a plurality of communication paths, and communication is performed by selecting one of the plurality of communication paths depending on the communication situation. Furthermore, in wireless communication systems, communication is performed by selecting one of a plurality of frequency channels. It is expected that selection of communication conditions such as communication routes and frequency channels will be performed through simple processing.

An object of the present invention is to select communication conditions through simple processing in a wireless communication system in which a plurality of communication conditions are defined.

The present invention is a wireless device that performs direct wireless communication with a wireless device, and the wireless device communicates with a wireless device according to an active communication path that is one of a plurality of communication paths formed by the wireless device. communicates with a wireless terminal, determines route evaluation information about the active communication route based on the wireless communication performed with the wireless device, and determines route evaluation information about the active communication route based on the route evaluation information. The communication route is changed to another communication route, and the communication route is a route that uses the radio as an initial relay and reaches the radio terminal through one or more relays, or is a route where the wireless terminal is the wireless terminal.

Preferably, communication is performed with the wireless terminal on the active communication path using an active frequency channel that is one of a plurality of frequency channels used on the active communication path, and the wireless device and and determining frequency evaluation information about the active frequency channel based on wireless communication performed between them, and changing the frequency channel to be the active frequency channel to another frequency channel based on the frequency evaluation information. .

Preferably, the frequency evaluation information is determined for each wireless communication performed with the wireless device in the past using the active frequency channel, depending on the degree of good communication status. This value is based on the evaluated evaluation value.

Preferably, the route evaluation information is determined for each wireless communication performed with the wireless device in the past and that follows the active communication route, depending on the degree of good communication status. This value is based on the evaluation value.

The present invention also provides a wireless device that performs direct wireless communication with a wireless device, and uses an active frequency channel that is one of a plurality of frequency channels to communicate with a wireless device on a communication path formed by the wireless device. communicates with the wireless terminal, determines frequency evaluation information about the active frequency based on the wireless communication performed with the wireless device, and determines the frequency evaluation information about the active frequency based on the frequency evaluation information. the frequency channel is changed to another frequency channel, and the communication route is a route that uses the radio as a first-stage repeater and reaches the radio terminal through one or more relays, or is a route where the wireless terminal is the wireless terminal.

Preferably, the frequency evaluation information is attached to each wireless communication performed with the wireless device in the past using the active frequency channel, depending on the degree of good communication status. This value is based on the evaluation value.

According to the present invention, communication conditions can be selected through simple processing in a wireless communication system in which a plurality of communication conditions are defined.

1 is a diagram showing the configuration of a wireless communication system. FIG. 6 is a diagram showing operations when communication is successful. FIG. 3 is a diagram showing an operation when retransmitting a downlink packet. FIG. 7 is a diagram illustrating an operation when the base device fails to transmit downlink packets three times. FIG. 7 is a diagram illustrating an operation when a slave device fails to transmit a response packet three times. FIG. 6 is a diagram illustrating an example of communication route evaluation values corresponding to each communication situation. FIG. 3 is a diagram showing an example of frequency evaluation values corresponding to each communication situation. FIG. 3 is a diagram illustrating an example of the hardware configuration of a parent device. FIG. 3 is a diagram illustrating an example of the hardware configuration of a slave device.

FIG. 1 shows the configuration of a wireless communication system 100 according to an embodiment of the present invention. The wireless communication system 100 includes a base device 10, relay devices 12-1 to 12-4, and a slave device 14 as wireless devices forming each communication base (node). In the example shown in FIG. 1, three communication paths 16-1 to 16-3 are formed in the wireless communication system 100. The communication path 16-1 is a communication path through which packets transmitted from the base device 10 are relayed by the relay device 12-1 and received by the slave device 14. Communication path 16-2 is a communication path through which packets transmitted from base device 10 are relayed in two stages by relay devices 12-2 and 12-3, and received by slave device 14. The communication path 16-3 is a communication path through which packets transmitted from the base device 10 are relayed by the relay device 12-4 and received by the slave device 14. The communication paths are not limited to those shown in FIG. 1, and a number of communication paths may be formed depending on the number of repeaters. Furthermore, some communication paths allow the base unit 10 to directly communicate wirelessly with the slave unit 14.

Packets transmitted by the wireless communication system 100 include route information that specifies a communication route. Although various types of route information can be considered, for example, it may be equivalent to information that lists the IDs of radio devices that constitute a communication route in order of relaying. The packet also includes a source ID as information that identifies the source one step before relaying (one hop before).

Each relay device relays a received packet only when the packet is transmitted from a specific wireless device determined by route information included in the packet. For example, the relay devices 12-1 and 12-4 relay the received packet when the source ID is the ID of the base device 10 and when the source ID is the ID of the slave device 14. Further, the relay device 12-2 relays the received packet when the source ID is the ID of the base device 10 and when the source ID is the ID of the relay device 12-3. Relay device 12-3 relays the received packet when the source ID is the ID of relay device 12-2 and when the source ID is the ID of slave device 14.

In the wireless communication system 100 according to the present embodiment, the base unit 10 as a wireless device determines one of the communication routes 16-1 to 16-3 as an active communication route, and transmits route information indicating the active communication route. The downlink packet including the downlink packet is transmitted to the handset 14 via the active communication path. Handset 14 transmits a response packet containing the same route information as the route information included in the received downlink packet to base unit 10 via the active communication path. The handset 14 may include measurement values of various sensors included in the handset 14 in the response packet. The base device 10 that has received the response packet acquires measurement values and the like from the response packet.

Each operation of the wireless communication system 100 when the communication path 16-1 is an active communication path will be described with reference to FIGS. 2 to 5. FIG. 2 shows the operation of the wireless communication system 100 when communication is successful. Base device 10 transmits downlink packet a toward relay device 12-1. The relay device 12-1 that received the downlink packet a relays the downlink packet a to the slave unit 14, and the slave unit 14 receives the downlink packet a.

The relay device 12-1 relays the downlink packet a to the slave device 14, and also transmits an acknowledge packet b (hereinafter referred to as an ACK packet) to the base device 10. By receiving the ACK packet b, the base device 10 recognizes that the downlink packet a has been received by the relay device 12-1. Furthermore, the handset 14 receives the downlink packet a and transmits the ACK packet c to the relay device 12-1. By receiving the ACK packet c, the relay device 12-1 recognizes that the downlink packet a has been received by the slave device 14.

The handset 14 that has received the downlink packet a transmits a response packet d including response data to the relay device 12-1. The response data may be, for example, data including measurement values of various sensors included in the handset 14. The relay device 12-1 that received the response packet d transmits the response packet d toward the base device 10. Base device 10 receives response packet d and extracts response data from response packet d. The relay device 12-1 relays the response packet d toward the base device 10, and transmits the ACK packet e toward the slave device 14. By receiving the ACK packet e, the handset 14 recognizes that the response packet d has been received by the relay device 12-1.

The base device 10 recognizes that the communication with the slave device 14 has been successful by receiving the response packet d in response to the transmission of the downlink packet a.

The wireless communication system 100 may be a system in which sensors such as a temperature sensor, a humidity sensor, an illuminance sensor, a vibration sensor, a water level sensor, etc. are mounted on the child device 14, and the parent device 10 collects the measured values of the sensors. Furthermore, the wireless communication system 100 may be a system in which the handset 14 acquires a measured value from a measuring device such as a gas meter or a power meter, and the base unit 10 collects the measured value.

3 to 5 show the operation of the wireless communication system 100 when communication fails. FIG. 3 shows the operation when the base device 10 transmits the downlink packet α to the relay device 12-1, does not receive an ACK packet even after a predetermined period of time has elapsed, and then transmits the downlink packet a. has been done. The processing from when base unit 10 transmits downlink packet a until it receives response packet d is similar to the operation shown in FIG. 1.

FIG. 4 shows the operation when the base unit 10 fails to transmit downlink packets three times. That is, after the base unit 10 transmitted the downlink packet α1, the ACK packet was not received even after a predetermined period of time had elapsed, so the base unit 10 transmitted the downlink packet α2, and after the base unit 10 transmitted the downlink packet α2, the ACK packet was not received for a predetermined period of time. The operation is shown in which the downlink packet α3 was transmitted because no ACK packet was received even after the elapsed time.

In FIG. 5, after the handset 14 receives the downlink packet a transmitted from the relay device 12-1 and transmits the ACK packet c toward the relay device 12-1, the handset 14 starts transmitting the response packet. The operation in the case of three failed attempts is shown. That is, since the handset 14 did not receive an ACK packet even after a predetermined period of time had elapsed after transmitting the response packet β1, it transmitted the response packet β2, and after the handset 14 had transmitted the response packet β2, the ACK packet was not received for a predetermined period of time. The operation is shown in which the handset 14 transmits a response packet β3 because it did not receive an ACK packet even after the elapsed time.

The base unit 10, the relay unit 12-1, and the slave unit 14 as radio devices that constitute nodes of the wireless communication system 100 transmit and receive packets on an active frequency channel that is one of a plurality of frequency channels. . That is, base unit 10 transmits downlink packet a on the active frequency. The relay device 12-1 can receive downlink packets on multiple frequency channels. The relay device 12-1 relays the downlink packet a to the handset 14 on the same frequency channel as the frequency channel on which the downlink packet a was received, and transmits the ACK packet c to the base device 10. As a result, the relay device 12-1 relays the downlink packet a on the active frequency channel and transmits the ACK packet c on the active frequency channel.

The handset 14 can receive downlink packets on multiple frequency channels. Handset 14 transmits ACK packet c and response packet d to repeater 12-1 on the same frequency channel as the frequency channel on which downlink packet a was received. As a result, the handset 14 transmits an ACK packet c and a response packet d on the active frequency channel. The relay device 12-1 relays the response packet d toward the base device 10 on the same frequency channel as the frequency channel on which the response packet d was received, and transmits the ACK packet e toward the slave device 14. As a result, the relay device 12-1 relays the response packet d on the active frequency channel and transmits the ACK packet e.

The base device 10, the relay device 12-1, and the slave device 14 as radio devices that constitute the nodes of the wireless communication system 100 execute carrier sense when transmitting packets. Carrier sense determines whether wireless communication is being performed by another wireless communication device on the frequency channel on which a packet is to be transmitted, and if wireless communication is being performed, it determines whether the wireless communication has ended. Later, it refers to the process of transmitting a packet on that frequency channel.

Base device 10 determines a communication path evaluation value for each communication sequence, with communication associated with transmitting downlink packets as one communication sequence. The communication route evaluation value indicates the degree of good communication condition, and the larger the value, the worse the communication condition. FIG. 6 shows examples of communication route evaluation values corresponding to each communication situation. There are two types of successful communication: retransmission, in which the downlink packet is retransmitted due to not receiving an ACK packet, and no retransmission, in which such retransmission is not performed. In the case of no retransmission, the communication path evaluation value is 0, and in the case of retransmission, the communication path evaluation value is 0.2.

In this way, in the case of retransmission, the communication path evaluation value is set to a value other than 0.

Communication failures include cases where an ACK packet is not received (no ACK packet is received), no response (no response packet is received), and carrier sense execution where a downlink packet is not transmitted due to carrier sense execution. In the example shown in FIG. 6, when ACK is not received, the communication path evaluation value is 2. If there is no response, the communication path evaluation value is 1. In the case of carrier sense execution, the communication route evaluation value is 0.

Base device 10 adds and totals communication route evaluation values for a predetermined number of communication sequences (for example, 10 times) to obtain an evaluation value as route evaluation information. If the evaluation value exceeds a predetermined value (for example, 4), base device 10 changes the active communication path to another communication path. Note that the active communication path may be changed to another communication path even when communication fails a predetermined number of times (for example, three times) or more. Base device 10 may change the communication route by changing route information included in the downlink packet. The communication route to be changed may be the one with the smallest evaluation value among the plurality of communication routes.

In this way, base unit 10 changes the active communication route based on the route evaluation value obtained for a predetermined number of communication sequences in the past. As a result, communication is performed using a route with a good communication condition among a plurality of communication routes through a simple process of calculation based on past communication quality.

As described above, when an ACK is not received, the communication path evaluation value is larger than when there is no response. When there is no response, the communication path evaluation value is larger than when there is retransmission. Furthermore, in the case where ACK is not received, the communication route evaluation value is set to be the largest value. This is because there is a high possibility that the communication situation with the relay device that performs direct wireless communication is not good, and communication quality may be improved by changing the active communication path. Further, the route evaluation value is set to 0 in the case of carrier sense execution. This is because when other wireless communication devices are communicating wirelessly using active frequency channels, it is unlikely that communication quality will improve even if you change only the communication route without changing the active frequency channel. be.

FIG. 7 shows an example of frequency evaluation values. The frequency evaluation value indicates the degree of good communication condition, and the larger the value, the worse the communication condition. In the case of successful transmission without retransmission, the frequency evaluation value is 0, and in the case of retransmission, the frequency evaluation value is 0.2. In this way, in the case of retransmission, the frequency evaluation value is set to a value other than 0.

In the example shown in FIG. 7, the frequency evaluation value is 1 when ACK is not received among transmission failures. If there is no response, the frequency evaluation value is 1. In the case of carrier sense execution, the frequency evaluation value is 3.

Base unit 10 adds and totals frequency evaluation values for a predetermined number of communication sequences (for example, 10 times) to obtain an evaluation value as frequency evaluation information. Base unit 10 changes the active frequency channel to another frequency channel when the evaluation value exceeds a predetermined value (for example, 4). Note that the active frequency channel may be changed to another frequency channel even when communication fails a predetermined number of times (for example, three times) or more. The active frequency channel to be changed may be the one with the smallest evaluation value among the plurality of frequency channels.

In this way, base unit 10 changes the active frequency channel based on the frequency evaluation value obtained for a predetermined number of communication sequences in the past. As a result, communication is performed using a frequency channel with good communication conditions among a plurality of frequency channels by simple processing of calculation based on past communication quality.

As described above, the frequency evaluation value when ACK is not received is the same as when there is no response. In both the case where ACK is not received and the case where there is no response, the frequency evaluation value is larger than that in the case where there is retransmission. Furthermore, in the case of carrier sense execution, the frequency evaluation value is the largest value. This is because there is a possibility that the frequency channel that is set as the active frequency channel is being used by another wireless communication device, and communication quality may be improved by changing the active frequency channel.

FIG. 8 shows an example of the hardware configuration of the base device 10. The base device 10 includes a base device control section 30, a base device radio section 32, and a storage section 34. The master control unit 30 may be a processor that executes a program stored in itself in advance or a program stored in the storage unit 34. The parent device control section 30 may cause the storage section 34 to temporarily store data obtained during the calculation process. The base unit control unit 30 controls the base unit radio unit 32. Base unit radio unit 32 transmits or receives packets under the control of base unit control unit 30. Specifically, base unit radio unit 32 transmits the downlink packet output from base unit control unit 30. It also receives response packets and ACK packets and outputs them to the base unit control unit 30.

In the embodiment described above, the base unit wireless unit 32 performs direct wireless communication with the first-stage relay device (radio device) on the communication path. The base unit radio unit 32 may directly perform wireless communication with the slave unit 14 (radio device) as a wireless terminal. The base unit control unit 30 controls the base unit radio unit to perform a process of communicating with the slave unit 14 according to an active communication path that is one of a plurality of communication paths formed by the relay machine and the slave unit 14. 32.

Base device radio unit 32 obtains route evaluation information regarding the active communication route based on the communication sequence (communication) performed with the radio device. Then, based on the route evaluation information, the communication route set as the active communication route is changed to another communication route. The communication path is a route leading to the handset 14 through one or more relays by one or more relay devices, or a path (wireless route where the device is a wireless terminal).

Furthermore, the base unit control unit 30 communicates with the slave unit 14 (wireless terminal on the active communication route) using an active frequency channel that is one of the plurality of frequency channels used in the active communication route. The communication process is executed together with the base unit wireless unit 32. Base unit control unit 30 obtains frequency evaluation information about the active frequency channel based on the communication sequence performed with the radio device, and based on the frequency evaluation information, the base unit control unit 30 selects the frequency channel to be the active frequency channel from other frequency channels. Change to said frequency channel.

FIG. 9 shows an example of the hardware configuration of the handset 14. The handset 14 includes a handset control section 40, a storage section 42, a sensor 44, and a handset radio section 46.

The slave device control unit 40 may be a processor that executes a program stored in itself in advance or a program stored in the storage unit 42. The handset control unit 40 may cause the storage unit 26 to temporarily store data obtained during arithmetic processing.

The sensor 44 may be a temperature sensor, humidity sensor, illuminance sensor, vibration sensor, water level sensor, or the like. The sensor 44 outputs the measured value to the slave device control section 40. The handset control unit 20 generates response data based on the measured value, and generates a response packet including the response data.

The handset control unit 40 controls the handset radio unit 46. The handset radio section 46 transmits or receives packets under the control of the handset control section 40. Specifically, the handset wireless section 46 transmits the response packet output from the handset control section 40. It also receives downlink packets and ACK packets, and outputs them to the handset controller 40.

10 base unit, 12-1 to 12-4 relay unit, 14 slave unit, 16-1 to 16-3 communication path, 30 base unit control unit, 32 base unit radio unit, 34, 42 storage unit, 40 slave unit control section, 44 sensor, 46 handset radio section, 100 wireless communication system.

Claims (6)

A wireless device that performs direct wireless communication with a wireless device,
communicating with a wireless terminal on the active communication path according to an active communication path that is one of a plurality of communication paths formed by the wireless device;
determining route evaluation information for the active communication route based on wireless communication performed with the radio;
changing the communication route to be the active communication route to another communication route based on the route evaluation information;
The communication path is
A wireless device characterized in that the wireless device is a first-stage relay device and the path is one or more relays to the wireless terminal, or the wireless device is the wireless terminal. The wireless device according to claim 1,
communicating with the wireless terminal on the active communication path using an active frequency channel that is one of a plurality of frequency channels used on the active communication path;
determining frequency evaluation information for the active frequency channel based on wireless communications conducted with the radio;
The wireless device is characterized in that the frequency channel set as the active frequency channel is changed to another frequency channel based on the frequency evaluation information. The wireless device according to claim 2,
The frequency evaluation information is
The value is based on an evaluation value determined according to the degree of good communication status for each wireless communication using the active frequency channel, which was performed with the wireless device in the past. A wireless device characterized by: The wireless device according to any one of claims 1 to 3,
The route evaluation information is
The value shall be based on an evaluation value determined according to the degree of good communication status for each wireless communication conducted with the radio device in the past and following the active communication route. A wireless device characterized by: A wireless device that performs direct wireless communication with a wireless device,
communicating with a wireless terminal on a communication path formed by the wireless device using an active frequency channel that is one of a plurality of frequency channels;
determining frequency evaluation information about the active frequency based on wireless communication performed with the radio;
changing the frequency channel to be the active frequency channel to another frequency channel based on the frequency evaluation information;
The communication path is
A wireless device characterized in that the wireless device is a first-stage relay device and the path is one or more relays to the wireless terminal, or the wireless device is the wireless terminal. The wireless device according to claim 5,
The frequency evaluation information is
The value shall be based on an evaluation value assigned to each communication using the active frequency channel in accordance with the degree of good communication status, for each wireless communication conducted with the radio device in the past. A wireless device characterized by:

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