# US 9,439,204 B2 · Wireless device and communication channel selection method

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- Number: US 9,439,204 B2
- Document ID: US9439204B2
- Status: Granted
- Kind: B2
- Application number: 14/481,041
- Filed: 2014-09-09
- Published: 2014-12-25
- Granted: 2016-09-06
- Earliest claimed: 2012-03-29
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Satoshi Kozaki; Kyohei Tanaka
- Web page: https://patentgrep.com/patent/US9439204B2

## CPC

- H04W 72/541: using the level of interference
- H04W 28/0236: {radio quality, e.g. interference, losses or delay}
- H04W 40/02: Communication route or path selection, e.g. power-based or shortest path routing
- H04W 40/16: based on interference
- H04W 72/02: Selection of wireless resources by user or terminal
- H04W 16/14: Spectrum sharing arrangements {between different networks}
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A wireless device includes a detecting unit, a sending unit, and a selecting unit. The detecting unit detects, for each communication channel while switching multiple communication channels, interference information. The sending unit sends to a destination wireless device, a packet in which the detected interference information are sequentially stored for each wireless device. The selecting unit receives the packet. When the wireless device does not correspond to the destination wireless device, the selecting unit transfers the packet. When the wireless device corresponds to the destination wireless device, the selecting unit selects, on the basis of the pieces of the interference information that are sequentially stored in the packet and the detected interference information, a communication channel.

## Claims

### Claim 1

A wireless device comprising:
a detecting unit configured to detect, for each communication channel while switching multiple communication channels, interference information indicating whether radio frequency interference from a peripheral wireless device is present;
a sending unit configured to send, before data is sent and received, to a destination wireless device that is the destination of the data, a packet in which pieces of the interference information detected by the detecting unit are sequentially stored for wireless devices; and
a selecting unit configured to receive the packet, to transfer, when the wireless device does not correspond to the destination wireless device that is the destination of the packet, the packet in which the interference information detected by the detecting unit is additionally stored, and to select, when the wireless device corresponds to the destination wireless device that is the destination of the packet, on the basis of the pieces of the interference information that are sequentially stored in the packet for wireless devices and on the basis of the interference information detected by the detecting unit, the communication channel that is used to send and receive the data from among the multiple communication channels.

### Claim 2 (depends on 1)

The wireless device according to claim 1, further comprising a channel reduction control unit configured to specify, when the interference information detected by the detecting unit indicates that the radio frequency interference with a use channel that is the communication channel selected by the selecting unit is present, from among peripheral wireless devices that send and receive data by using the use channel, an interference wireless device that emits a radio wave that is equal to or greater than a threshold and configured to send, to the specified interference wireless device, a channel reduction request packet that requests the specified interference wireless device to stop to send the data performed by using the use channel.

### Claim 3 (depends on 2)

The wireless device according to claim 2, wherein, when the channel reduction control unit receives the channel reduction request packet from another wireless device and when the wireless device is sending data by using the use channel and is sending data by using another communication channel that is other than the use channel, the channel reduction control unit stops to send the data performed by using the use channel.

### Claim 4 (depends on 2)

The wireless device according to claim 2, wherein, when the channel reduction control unit receives the channel reduction request packet from another wireless device and when the wireless device is not sending data by using the use channel, the channel reduction control unit transfers the channel reduction request packet to the other wireless device that is the send source of the data.

### Claim 5

A communication channel selection method performed by a computer, the communication channel selection method comprising:
detecting, for each communication channel while switching multiple communication channels, interference information indicating whether radio frequency interference from a peripheral wireless device is present;
sending, to a destination wireless device that is the destination of data before the data is sent and received, a packet in which the detected pieces of interference information are sequentially stored for wireless devices; and
receiving the packet, transferring, when the computer does not correspond to the destination wireless device that is the destination of the packet, the packet in which the detected interference information is additionally stored, and selecting, when the computer corresponds to the destination wireless device that is the destination of the packet, on the basis of the pieces of interference information that are sequentially stored in the packet for wireless devices and on the basis of the detected interference information, the communication channel that is used to send and receive the data from among the multiple communication channels.