JP2014241480A - Communication apparatus, communication method and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus and communication method, capable of improving a communication efficiency in radio communication by selecting a band used in each of a plurality of frequency band.SOLUTION: The communication apparatus 10a includes: a use band selection section 105 that selects a band used in each of a plurality of frequency bands; a communication section 101 that communicates with any other communication apparatus using the selected band. The use band selection section selects a maximum band communicatable in each of the plurality of frequency bands.

Description

  The present invention relates to a technique for improving communication efficiency.

  Conventionally, IEEE802.11a and IEEE802.11n are used as a standard of a wireless LAN (Local Area Network) using a 5 GHz band. In IEEE 802.11a, wireless communication is performed using a frequency band of 20 MHz per channel. In IEEE802.11n, channel bonding is proposed as a technique for performing communication using two adjacent channels simultaneously. As a result, the wireless LAN access point (hereinafter referred to as “AP”) can use the frequency band of two channels (40 MHz), thereby realizing high-speed communication.

  In recent years, IEEE 802.11ac that can theoretically transmit at 1 Gbps or more has been proposed as a next-generation communication standard of IEEE 802.11n (see, for example, Patent Document 1). In IEEE802.11ac, the AP can use a frequency band corresponding to eight channels (maximum 160 MHz) by channel bonding, so that communication speed can be further increased than that of IEEE802.11n.

JP 2012-70090 A

  However, when the AP performs communication using the frequency band of 160 MHz by channel bonding, if each channel of the frequency band used by the AP is used by another AP, the AP and the other AP There is a risk that communication opportunities will overlap. When communication opportunities overlap, data collision occurs between the AP and another AP. Therefore, the AP performs CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) in order to avoid data collision with other APs. Specifically, the AP detects whether or not another AP is communicating, and when the other AP is communicating, it does not transmit data and the other AP is communicating. If not, send the data. Thereby, data collision between the AP and another AP can be avoided. However, the AP may not be able to perform communication using the entire frequency band of 160 MHz. That is, the AP may only be able to communicate using a frequency band of 60 MHz or 40 MHz. In the worst case, even communication may not be possible. When such a problem occurs, the AP cannot efficiently use the frequency band used by channel bonding. Therefore, there has been a problem that communication efficiency in AP wireless communication is reduced.

  In view of the above circumstances, an object of the present invention is to provide a technique for improving communication efficiency in wireless communication.

  One aspect of the present invention is a communication device including a use band selection unit that selects a band to be used in each of a plurality of frequency bands, and a communication unit that communicates with another communication device using the selected band. It is.

  One aspect of the present invention is the communication device described above, wherein the use band selection unit selects a maximum band in which communication is possible in each of the plurality of frequency bands.

  One aspect of the present invention is the communication device described above, further including a transmission signal generation unit that generates a transmission signal transmitted in each of a plurality of frequency bands, and the transmission signal generation unit generates the transmission signal. In this case, transmission data for a band selected for each frequency band and a transmission number indicating the order of the transmission data are added to the transmission signal.

  One aspect of the present invention is a communication method including a use band selection step of selecting a band to be used in each of a plurality of frequency bands, and a communication step of communicating with another communication device using the selected band. It is.

  According to one embodiment of the present invention, a use band selection step of selecting a band to be used in each of a plurality of frequency bands and a communication step of communicating with another communication apparatus using the selected band are executed on a computer It is a computer program for making it happen.

  According to the present invention, communication efficiency in wireless communication can be improved.

It is a block diagram which shows the system configuration | structure of the radio | wireless communications system in 1st Embodiment of this invention. It is a block diagram of a bandwidth information database. It is a figure which shows the specific example of the transmission signal in this invention. It is a flowchart which shows the flow of the use band selection process in 1st Embodiment of this invention. It is a flowchart which shows the flow of the use band selection process in 1st Embodiment of this invention. It is a flowchart which shows the flow of a process of the radio | wireless communication stem in 1st Embodiment of this invention. It is a sequence diagram which shows operation | movement of the radio | wireless communications system in 1st Embodiment of this invention. It is a block diagram which shows the system configuration | structure of the radio | wireless communications system in 2nd Embodiment of this invention. It is a sequence diagram which shows operation | movement of the radio | wireless communications system in 2nd Embodiment of this invention.

Hereinafter, specific configuration examples (first embodiment and second embodiment) of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a system configuration of a radio communication system according to the first embodiment of the present invention. The wireless communication system in the first embodiment includes an AP 10a and a communication terminal 20a. 1 shows a configuration in which the wireless communication system includes one AP 10a, the wireless communication system may be configured to include two or more APs 10a. 1 shows a configuration in which the wireless communication system includes one communication terminal 20a, the wireless communication system may be configured to include two or more communication terminals 20a.

  The AP 10a is a wireless LAN (Local Area Network) access point, and communicates with the communication terminal 20a belonging to the own device (AP 10a). The AP 10a can communicate using a plurality of channels simultaneously by channel bonding. Further, the AP 10a can communicate using a plurality of frequency bands (hereinafter, “frequency bands” are simply referred to as “bands”) at the same time. For example, the AP 10a communicates with the communication terminal 20a using the 2.4 GHz band and the 5 GHz band at the same time.

  The communication terminal 20a is configured using, for example, an information processing device such as a smartphone, a mobile phone, a PDA (Personal Digital Assistant), a game device, a tablet device, or a personal computer. The communication terminal 20a can communicate using a plurality of channels simultaneously by channel bonding. Further, the communication terminal 20a can communicate using a plurality of frequency bands at the same time. For example, the communication terminal 20a simultaneously communicates with the AP 10a using the 2.4 GHz band and the 5 GHz band.

  Hereinafter, specific configurations of the AP 10a and the communication terminal 20a will be described. First, the functional configuration of the AP 10a will be described. The AP 10a includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a wireless communication program. By executing the wireless communication program, the AP 10a is an apparatus including the communication unit 101, the channel scanning unit 102, the determination unit 103, the band information storage unit 104, the used band selection unit 105, the transmission signal generation unit 106, and the transmission signal synthesis unit 107. Function. All or some of the functions of the AP 10a may be realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). The wireless communication program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. The wireless communication program may be transmitted / received via an electric communication line.

The communication unit 101 communicates with the communication terminal 20a. The communication unit 101 communicates with the communication terminal 20a using, for example, a plurality of frequency bands simultaneously. More specifically, the communication unit 101 communicates with the communication terminal 20a using the 2.4 GHz band and the 5 GHz band at the same time.
The channel scanning unit 102 periodically performs carrier sense to detect whether another communication device (for example, another AP or the communication terminal 20a) is communicating with all channels. For example, when another communication device is communicating, the channel scanning unit 102 detects the other communication device by receiving a beacon or a packet. Further, when a beacon or a packet is received, the channel scanning unit 102 acquires a received signal strength indication (RSSI) of the received beacon or packet.

  The determination unit 103 determines whether there is an available bandwidth based on the acquired RSSI value. Specifically, when the RSSI value is equal to or greater than the threshold, the determination unit 103 determines that the band whose RSSI value is equal to or greater than the threshold is not a usable band. On the other hand, when the RSSI value is less than the threshold, the determination unit 103 determines that the band having the RSSI value less than the threshold is an available band.

  The available bandwidth represents a bandwidth that does not affect the communication of the own device even when another communication device is communicating. That is, when there is a band whose RSSI value is equal to or greater than the threshold, the own apparatus and other communication apparatuses using the band are located at a relatively close distance. Therefore, there is a high risk of affecting the communication of the own device. As a result, the own device cannot communicate. On the other hand, when there is a band whose RSSI value is less than the threshold value, the own apparatus and another communication apparatus using the band are located at a relatively long distance. Therefore, there is a low risk of affecting the communication of the own device. As a result, the device itself can communicate.

  The band information storage unit 104 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The bandwidth information storage unit 104 stores a bandwidth information database. Hereinafter, the bandwidth information database will be described with reference to FIG. FIG. 2 is a configuration diagram of the bandwidth information database. The band information database includes a plurality of records 30 representing information on a plurality of frequency band bands used for communication. The record 30 has each value of a communication pattern number, a total communication band, a 5 GHz band communication band, and a 2.4 GHz band communication band. The value of the communication pattern number represents a number for identifying a combination pattern of a plurality of frequency bands used for communication represented by the record 30. The value of the total communication band is a total value of bands of a plurality of frequency bands used for communication represented by the record 30. In the specific example of FIG. 2, “MHz” is set as the unit of the total communication band. The value of the 5 GHz band communication band represents a band used in the 5 GHz band among a plurality of frequency bands used for communication represented by the record 30. In the specific example of FIG. 2, “MHz” is set as the unit of the 5 GHz band communication band. The value of the 2.4 GHz band communication band represents a band used in the 2.4 GHz band among a plurality of frequency bands used for communication represented by the record 30. In the specific example of FIG. 2, “MHz” is set as the unit of the 2.4 GHz band communication band.

  In the example shown in FIG. 2, there are 14 communication pattern numbers in the bandwidth information database. These 14 communication pattern numbers are “1”, “2”, “...”, “14”. In FIG. 2, the top row of the bandwidth information database has a communication pattern number value of “1”, a total communication bandwidth value of “200”, a 5 GHz bandwidth communication bandwidth value of “160”, and a 2.4 GHz bandwidth communication. The band value is “40”. That is, in the combination pattern of the bands of the plurality of frequency bands used for communication identified by the communication pattern number “1”, the total value of the bands of the plurality of frequency bands used for communication is “200 MHz”, and 5 GHz. The band used in the band is “160 MHz”, and the band used in the 2.4 GHz band is “40 MHz”.

  2, the third row of the band information database has a communication pattern number value “3”, a total communication band value “160”, and a 5 GHz band communication band value “160”. The value of the 4 GHz band communication band is “0”. That is, in the combination pattern of the bands of the plurality of frequency bands used for communication identified by the communication pattern number “3”, the total value of the bands of the plurality of frequency bands used for communication is “160 MHz”, and 5 GHz The band used in the band is “160 MHz”, and the band used in the 2.4 GHz band is “0 MHz”. That is, in this combination pattern, since all the bands in the 2.4 GHz band are used for other communication apparatuses, it represents that only the 5 GHz band can be used.

  2, the 13th row of the bandwidth information database has a communication pattern number value “13”, a total communication bandwidth value “40”, and a 5 GHz bandwidth communication bandwidth value “0”. The value of the 4 GHz band communication band is “40”. That is, the combined pattern of the bands of the plurality of frequency bands used for communication identified by the communication pattern number “13” has a total value of “40 MHz” of the bands of the plurality of frequency bands used for communication, and is 5 GHz. It is shown that the band used in the band is “0 MHz” and the band used in the 2.4 GHz band is “40 MHz”. That is, in this combination pattern, all the bands in the 5 GHz band are used for other communication devices, and thus only the band in the 2.4 GHz band can be used.

Returning to FIG. 1, the description of the AP 10a will be continued.
Based on the determination result of the determination unit 103, the use band selection unit 105 selects a band to be used in each of a plurality of frequency bands (hereinafter referred to as “use band”). For example, the use band selection unit 105 selects a use band to be used in the 2.4 GHz band from a band determined to be a usable band in the 2.4 GHz band. For example, when it is determined that two adjacent bands (bands of 40 MHz for two channels) are usable bands, the use band selecting unit 105 sets the two adjacent bands to be used bands in the 2.4 GHz band. select.

In addition, the use band selection unit 105 selects a use band to be used in the 5 GHz band from the bands determined to be usable in the 5 GHz band. For example, when it is determined that four adjacent bands (80 MHz band for four channels) can be used, the use band selection unit 105 selects the four adjacent bands as use bands to be used in the 5 GHz band. .
Thereafter, the used band selection unit 105 refers to the band information database and acquires the value of the communication pattern number corresponding to the selected combination of used bands. The use band selection unit 105 outputs the acquired communication pattern number, each value of the use band of the 5 GHz band, and the use band of the 2.4 GHz band to the transmission signal generation unit 106.

  The transmission signal generation unit 106 generates a transmission signal using each value output from the use band selection unit 105. Specifically, the transmission signal generation unit 106 generates a 5 GHz band signal using the value of the 5 GHz band use band, the value of the communication pattern number, and the transmission data for the use band. At this time, the transmission signal generation unit 106 stores a sequence number representing the order of transmission data in the header of the signal for 5 GHz band. In addition, the transmission signal generation unit 106 generates a 2.4 GHz band signal using the 2.4 GHz band use band value, the communication pattern number value, and the transmission data for the use band. At this time, the transmission signal generation unit 106 stores a sequence number representing the order of transmission data in the header of the 2.4 GHz band signal. Thereafter, the transmission signal generation unit 106 outputs the generated 2.4 GHz band signal and 5 GHz band signal to the communication unit 101.

  The transmission signal synthesis unit 107 synthesizes the 2.4 GHz band signal and the 5 GHz band signal received by the communication unit 101. Specifically, the transmission signal combining unit 107 acquires sequence numbers and transmission data stored in the 2.4 GHz band signal and the 5 GHz band signal. Then, the transmission signal combining unit 107 arranges the transmission data based on the acquired sequence number, thereby combining the transmission data of the 2.4 GHz band signal and the transmission data of the 5 GHz band signal into one transmission data.

  Next, the functional configuration of the communication terminal 20a will be described. The communication terminal 20a includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and executes a wireless communication program. By executing the wireless communication program, the communication terminal 20a functions as an apparatus including the communication unit 201, the transmission signal synthesis unit 202, the band information storage unit 203, the used band selection unit 204, and the transmission signal generation unit 205. All or some of the functions of the communication terminal 20a may be realized using hardware such as an ASIC, PLD, or FPGA. The wireless communication program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. The wireless communication program may be transmitted / received via an electric communication line.

The communication unit 201 communicates with the AP 10a. The communication unit 201 performs communication with the AP 10a using, for example, a plurality of frequency bands simultaneously. More specifically, the communication unit 201 performs communication with the AP 10a by simultaneously using the 2.4 GHz band and the 5 GHz band.
The transmission signal combining unit 202 combines the 2.4 GHz band signal and the 5 GHz band signal received by the communication unit 201. Specifically, the transmission signal combining unit 202 acquires sequence numbers and transmission data stored in the 2.4 GHz band signal and the 5 GHz band signal. Then, the transmission signal combining unit 202 arranges the transmission data based on the acquired sequence numbers, thereby combining the transmission data of the 2.4 GHz band signal and the transmission data of the 5 GHz band signal into one transmission data.

  The band information storage unit 203 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The bandwidth information storage unit 203 stores a bandwidth information database. Note that the bandwidth information database stored in the bandwidth information storage unit 203 has the same configuration as the bandwidth information database stored in the bandwidth information storage unit 104. Therefore, the description about the bandwidth information database is omitted.

Based on the 2.4 GHz band signal and the 5 GHz band signal received by the communication unit 201, the use band selection unit 204 selects the use band of the own device (communication terminal 20a). Specifically, the use band selection unit 204 acquires the value of the communication pattern number from the 2.4 GHz band signal and the 5 GHz band signal. The used band selection unit 204 refers to the band information database stored in the band information storage unit 203 and selects the record 30 corresponding to the acquired communication pattern number. Thereafter, the use band selection unit 204 acquires the value of the 5 GHz band communication band and the value of the 2.4 GHz band communication band from the selected record 30. The use band selection unit 204 selects each acquired value as a use band of the own device.
The transmission signal generation unit 205 generates a 2.4 GHz band signal and a 5 GHz band signal based on the selected use band. At this time, the transmission signal generation unit 205 stores the sequence numbers representing the order of the transmission data in the headers of the 2.4 GHz band signal and the 5 GHz band signal, respectively.

FIG. 3 is a diagram showing a specific example of transmission signals (2.4 GHz band signal and 5 GHz band signal) in the present invention.
FIG. 3A is a configuration diagram of a transmission signal. The transmission signal shown in FIG. 3A has fields for storing each value of a preamble, a sequence number, detection result instruction information, a destination terminal identifier, a transmission source terminal identifier, and data. In the preamble field, information relating to a signal for giving a timing for synchronization is stored. In the sequence number (transmission number) field, information indicating the order of transmission data is stored. In the field of the detection result instruction information, a communication pattern number used in communication performed between the AP 10a and the communication terminal 20a (hereinafter referred to as “AP-terminal communication”) and information on a used band are stored. Is done. For example, when the transmission signal is a signal for a 5 GHz band, the field of the detection result instruction information includes a communication pattern number and information on a used band used in the 5 GHz band (information indicating which bandwidth is used). Stored. Further, when the transmission signal is a 2.4 GHz band signal, a communication pattern number and information on a used band used in the 2.4 GHz band are stored in the detection result instruction information field.

  The destination terminal identifier field stores the MAC address of the communication device (for example, the communication terminal 20a) that is the destination of the transmission data. The field of the transmission source terminal identifier stores the MAC address of the communication device (for example, the AP 10a) that is the transmission data transmission source. Transmission data to be transmitted is stored in the data field.

  FIG. 3B is a diagram showing a specific configuration of transmission data stored in the transmission signal. In the transmission data shown in FIG. 3B, there are a plurality of data (for example, A1 to A20 in the case of data A) for each item “data A”, “data B”, and “data C”. . “Data A” is data transmitted in the first communication, “Data B” is data transmitted in the second communication, and “Data C” is transmitted in the third communication. It is data.

  Hereinafter, the transmission signal transmission / reception method will be described in detail with reference to FIG. Note that the bandwidth used in the AP-terminal communication in this description is defined as follows. The use band of the 2.4 GHz band is “40 MHz”, and the use band of the 5 GHz band is “160 MHz”. That is, the case of the communication pattern number “1” in the bandwidth information database will be described. The data size of each piece of data (for example, A1) in FIG. 3B is “10” Mbps.

  The transmission signal generation unit 106 of the AP 10a generates a 2.4 GHz band signal and a 5 GHz band signal. Specifically, the transmission signal generation unit 106 stores “A16” in the sequence number field of the header, and the communication pattern number “1” and information on the use band “160 MHz” of 5 GHz in the detection result instruction information field. The 5 GHz band signal is generated by storing the data “A1 to A16” for the use band in the data field.

  Further, the transmission signal generation unit 106 stores “A20” in the sequence number field of the header, the communication pattern number “1” and the information on the use band “40 MHz” of 2.4 GHz in the detection result instruction information field, By storing the data “A17 to A20” for the used band in the data field, a 2.4 GHz band signal is generated. And the communication part 101 of AP10a transmits the transmission signal produced | generated using a some frequency band simultaneously to the communication terminal 20a.

The communication unit 201 of the communication terminal 20a receives the transmission signal transmitted from the AP 10a for each frequency band. Thereafter, the transmission signal combining unit 202 combines the received signals. Specifically, transmission signal combining section 202 combines transmission data by arranging transmission data based on sequence numbers stored in each received transmission signal.
This is the end of the description of the transmission signal transmission / reception method.

  4 and 5 are flowcharts showing the flow of the used band selection processing in the first embodiment of the present invention. The channel scan unit 102 performs carrier sense on all channels by periodically performing channel scan (step S101). The determination unit 103 determines whether or not the 2.4 GHz band is used based on the carrier sense result (step S102). When the 2.4 GHz band is not used (step S102—NO), the use band selecting unit 105 selects the 40 MHz band (for two channels) as the 2.4 GHz band use band (step S103). In this case, any band may be selected as long as it is a band corresponding to two adjacent bands. Thereafter, the process proceeds to step S107.

  On the other hand, when the 2.4 GHz band is used (YES in step S102), the determination unit 103 determines whether the 40 MHz band can be used (step S104). When the 40 MHz band can be used (YES in step S104), the use band selection unit 105 selects the 40 MHz band as the use band of the 2.4 GHz band (step S103). The band selected at this time may be any band as long as it is a band for two adjacent bands and the RSSI value is less than the threshold value. Thereafter, the process proceeds to step S107.

  On the other hand, when the 40 MHz band cannot be used (step S104—NO), the determination unit 103 determines whether the 20 MHz band can be used (step S105). When the 20 MHz band can be used (YES in step S105), the use band selection unit 105 selects the 20 MHz band as the use band of the 2.4 GHz band (step S106). As long as the band selected at this time is a band whose RSSI value is less than the threshold, any band may be selected. Thereafter, the process proceeds to step S107. On the other hand, when the 20 MHz band cannot be used (step S105—NO), the determination unit 103 determines whether the 5 GHz band of 160 MHz (eight channels) can be used (step S107).

  When the 160 MHz band can be used (step S107: YES), the use band selection unit 105 selects the 160 MHz band as the use band of the 5 GHz band (step S108). Thereafter, the process ends. On the other hand, when the 160 MHz band cannot be used (step S107—NO), the determination unit 103 determines whether the 80 MHz band (for four channels) can be used (step S109).

  When the 80 MHz band can be used (step S109—YES), the use band selection unit 105 selects the 80 MHz band as the use band of the 5 GHz band (step S110). Thereafter, the process ends. On the other hand, when the 80 MHz band cannot be used (step S109—NO), the determination unit 103 determines whether the 40 MHz band can be used (step S111).

  When the 40 MHz band can be used (step S111—YES), the use band selection unit 105 selects the 40 MHz band as the use band of the 5 GHz band (step S112). Thereafter, the process ends. On the other hand, when the 40 MHz band cannot be used (step S111—NO), the determination unit 103 determines whether the 20 MHz band can be used (step S113).

  When the 20 MHz band can be used (step S113: YES), the use band selection unit 105 selects the 20 MHz band as the use band of the 5 GHz band (step S114). Thereafter, the process ends. On the other hand, when the 20 MHz band cannot be used (step S113—NO), the process is terminated.

FIG. 6 is a flowchart showing the flow of processing of the wireless communication system in the first embodiment of the present invention.
The channel scan unit 102 performs carrier sense for all channels by periodically performing channel scan (step S201). The used band selection unit 105 selects a used band for each frequency band based on the carrier sense result (step S202). Specifically, the use band selection unit 105 selects a band that can be used in the 2.4 GHz band and a band that can be used in the 5 GHz band.

  The transmission signal generation unit 106 generates a transmission signal based on the selected use band (step S203). Specifically, the transmission signal generation unit 106 stores the sequence number and 2.4 GHz band use band information in the header, and stores the transmission data corresponding to the use band in the body for the 2.4 GHz band. Generate a signal. Further, the 5 GHz band signal is generated by storing the sequence number and the information on the 5 GHz band use band in the header and storing the transmission data corresponding to the use band in the body.

  The communication unit 101 transmits the generated transmission signals (2.4 GHz band signal and 5 GHz band signal) to the communication terminal 20a using a plurality of frequency bands at the same time (step S204). The communication unit 101 receives a transmission signal from the communication terminal 20a (step S205). Specifically, the communication unit 101 receives a plurality of transmission signals from a plurality of frequency bands. The transmission signal combining unit 107 combines the transmission data by aligning the transmission data based on the sequence numbers stored in the plurality of received transmission signals (step S206). Thereafter, the process ends.

FIG. 7 is a sequence diagram showing an operation of the wireless communication system in the first embodiment of the present invention.
The channel scan unit 102 of the AP 10a performs carrier sense (step S301). As a result of the carrier sense, the channel scanning unit 102 does not receive a beacon or a packet because there is no other AP performing communication in the vicinity (step S302). Further, as a result of the carrier sense, the channel scanning unit 102 does not receive a beacon or a packet because there is no communication terminal 20a performing communication in the vicinity (step S303).

  The use band selection unit 105 selects a use band for each frequency band (step S304). For example, since there is no other communication apparatus that performs communication in the 2.4 GHz band, the use band selection unit 105 selects the 40 MHz band as the use band used in the 2.4 GHz band. In addition, since there is no other communication device that performs communication in the 5 GHz band, the use band selection unit 105 selects the 160 MHz band as the use band to be used in the 5 GHz band.

  Thereafter, the used band selection unit 105 reads the band information database stored in the band information storage unit 104. The use band selection unit 105 refers to the item of the 5 GHz band communication band and the item of 2.4 GHz band communication band of the read band information database, and uses the selected use band in the 5 GHz band and the 2.4 GHz band, respectively. The record 30 corresponding to the combination of used bands is selected. The use band selection unit 105 acquires the value of the communication pattern number from the selected record 30. The used band selection unit 105 outputs the acquired communication pattern number to the communication unit 101. The communication unit 101 instructs to perform communication using the communication band corresponding to the communication pattern number by transmitting the value of the communication pattern number to the communication terminal 20a (step S305).

  The communication unit 201 of the communication terminal 20a receives the value of the communication pattern number from the AP 10a. The used band selection unit 204 refers to the item of the communication pattern number in the band information database and selects the record 30 corresponding to the received communication pattern number. The use band selection unit 204 acquires values of the 5 GHz band communication band and the 2.4 GHz band communication band from the selected record 30. The used band selecting unit 204 selects each acquired value as a used band used by the own device (communication terminal 20a). Thereafter, the communication unit 201 communicates with the AP 10a using the selected use band (step S306).

  When a certain time has elapsed, the channel scan unit 102 of the AP 10a performs carrier sense (step S307). The channel scan unit 102 receives a beacon and a packet because there is another AP communicating in the vicinity as a result of the carrier sense (step S308). At this time, the channel scanning unit 102 acquires the RSSI of the received beacon and packet. Further, the channel scanning unit 102 receives a beacon and a packet because there is a communication terminal 20a performing communication in the vicinity as a result of carrier sense (step S309). At this time, the channel scanning unit 102 acquires the RSSI of the received beacon and packet.

  The use band selection unit 105 selects a use band for each frequency band (step S310). For example, since there is another communication device that performs communication in the 2.4 GHz band, the use band selection unit 105 sets the band where the RSSI value is less than the threshold or the band not used in the 2.4 GHz band. Select the band to be used in. In addition, since there is another communication device that performs communication in the 5 GHz band, the use band selection unit 105 uses a band in which the RSSI value is less than the threshold or a band that is not used in the 5 GHz band. Select the band.

  Thereafter, the used band selection unit 105 reads the band information database stored in the band information storage unit 104. The use band selection unit 105 refers to the read band information database, and uses the use band and the 2.4 GHz band used in the 5 GHz band selected from the 5 GHz band communication band item and the 2.4 GHz band communication band item, respectively. The record 30 corresponding to the combination of used bandwidths is selected. The use band selection unit 105 acquires the value of the communication pattern number from the selected record 30. The used band selection unit 105 outputs the acquired communication pattern number to the communication unit 101. The communication unit 101 instructs to perform communication using the communication band corresponding to the communication pattern number by transmitting the value of the communication pattern number to the communication terminal 20a (step S311).

  The communication unit 201 of the communication terminal 20a receives the value of the communication pattern number from the AP 10a. The used band selection unit 204 refers to the item of the communication pattern number in the band information database and selects the record 30 corresponding to the received communication pattern number. The use band selection unit 204 acquires values of the 5 GHz band communication band and the 2.4 GHz band communication band from the selected record 30. The used band selecting unit 204 selects each acquired value as a used band used by the own device (communication terminal 20a). Thereafter, the communication unit 201 communicates with the AP 10a using the selected use band (step S312).

  According to the wireless communication system configured as described above, communication is performed using a plurality of frequency bands at the same time. Specifically, the AP 10a selects a use band for AP-terminal communication according to the use situation of each of a plurality of frequency bands. Next, the AP 10a generates a transmission signal storing data for the selected band, and simultaneously transmits the transmission signal to the communication terminal 20a using a plurality of frequency bands. Therefore, the AP 10a can effectively use the broadband by channel bonding when there are few other communication devices using the band around the own device or when the possibility of affecting the communication of the own device is low. Can do. Furthermore, by using a plurality of frequency bands at the same time, it is possible to perform communication at a higher speed than when using one frequency band. Therefore, it is possible to improve communication efficiency in wireless communication.

In addition, the communication terminal 20a synthesizes transmission signals by aligning transmission signals received from a plurality of frequency bands based on sequence numbers. Thereby, transmission signals received from a plurality of frequency bands can be restored. Furthermore, by using a plurality of frequency bands, it becomes possible to transmit a large amount of data in one communication. Therefore, it is possible to improve communication efficiency in wireless communication.
In addition, since the 5 GHz band has a larger propagation loss than the 2.4 GHz band, the communication quality is deteriorated in communication over a long distance. However, since communication is also performed using the 2.4 GHz band, it is possible to suppress a decrease in communication quality in communication far away than when performing communication only in the 5 GHz band.

<Modification>
Each value of the sequence number and the detection result instruction information may be stored in the data portion of the transmission signal. Further, only the sequence number may be stored in the data portion. In this case, the sequence number is stored in association with the transmission data to be transmitted. Further, only the detection result instruction information may be stored in the data portion.
In the present embodiment, the transmission data stored in the 2.4 GHz band signal and the 5 GHz band signal is stored for the band used in the AP-terminal communication. However, the transmission data is not necessarily used in the AP-terminal communication. It is not necessary to store transmission data for the band to be used.

[Second Embodiment]
FIG. 8 is a block diagram showing a system configuration of a radio communication system according to the second embodiment of the present invention. The wireless communication system of the present invention includes an AP 10b and a communication terminal 20b. 8 shows a configuration in which the wireless communication system includes one AP 10b, the wireless communication system may be configured to include two or more APs 10b. 8 shows a configuration in which the wireless communication system includes one communication terminal 20b, the wireless communication system may be configured to include two or more communication terminals 20b.

  Hereinafter, specific configurations of the AP 10b and the communication terminal 20b will be described. First, the functional configuration of the AP 10b will be described. The AP 10b includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and executes a wireless communication program. By executing the wireless communication program, the AP 10b functions as an apparatus including the communication unit 101, the band information storage unit 104, the transmission signal generation unit 106, and the transmission signal synthesis unit 107. Note that all or part of each function of the AP 10b may be realized using hardware such as an ASIC, a PLD, or an FPGA. The wireless communication program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. The wireless communication program may be transmitted / received via an electric communication line.

  The AP 10b is different in configuration from the AP 10a in that it does not include the channel scan unit 102 and the determination unit 103. The AP 10b is the same as the AP 10a in other configurations. Therefore, description of AP10b is abbreviate | omitted.

  Next, the functional configuration of the communication terminal 20b will be described. The communication terminal 20b includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and executes a wireless communication program. By executing the wireless communication program, the communication terminal 20b includes a communication unit 201, a transmission signal synthesis unit 202, a band information storage unit 203, a used band selection unit 204, a transmission signal generation unit 205, a channel scanning unit 206, and a determination unit 207. Functions as a device. Note that all or some of the functions of the communication terminal 20b may be realized using hardware such as an ASIC, PLD, or FPGA. The wireless communication program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. The wireless communication program may be transmitted / received via an electric communication line.

  The communication terminal 20b is different in configuration from the communication terminal 20a in that it includes a channel scan unit 206 and a determination unit 207. The communication terminal 20b is the same as the communication terminal 20a in other configurations. Therefore, description of the communication terminal 20b as a whole is omitted, and only the channel scanning unit 206 and the determination unit 207 are described.

  The channel scanning unit 206 periodically performs carrier sense to detect whether another communication device (for example, the AP or the communication terminal 20b) is communicating with all channels. For example, when another communication device is communicating, the channel scan unit 206 detects the other communication device by receiving a beacon or a packet. Further, when a beacon or packet is received, the channel scan unit 206 acquires the RSSI of the received beacon or packet.

  The determination unit 207 determines whether there is an available bandwidth based on the acquired RSSI value. Specifically, when the RSSI value is equal to or greater than the threshold, the determination unit 207 determines that the band whose RSSI value is equal to or greater than the threshold is not an available band. On the other hand, when the RSSI value is less than the threshold, the determination unit 207 determines that the band having the RSSI value less than the threshold is an available band. In this case, the used band selecting unit 204 selects the used band based on the determination result of the determining unit 207. For example, the use band selection unit 204 selects a use band from bands determined to be usable in the 2.4 GHz band. In addition, the use band selection unit 204 selects a use band from the bands determined to be usable in the 5 GHz band.

FIG. 9 is a sequence diagram showing an operation of the radio communication system according to the second embodiment of the present invention.
The channel scan unit 206 of the communication terminal 20b performs carrier sense (step S401). As a result of the carrier sense, the channel scan unit 206 does not receive a beacon or a packet because there is no other communication terminal performing communication in the vicinity (step S402). Further, as a result of carrier sense, the channel scan unit 206 does not receive a beacon or a packet because there is no AP communicating in the vicinity (step S403).

  The use band selection unit 204 selects a use band for each frequency band (step S404). Specifically, the use band selection unit 204 selects the 40 MHz band as the use band in the 2.4 GHz band because there is no other communication device that performs communication in the 2.4 GHz band. Further, since there is no other communication apparatus that performs communication in the 5 GHz band, the use band selection unit 204 selects the 160 MHz band as the use band in the 5 GHz band.

  Thereafter, the used band selection unit 204 reads the band information database stored in the band information storage unit 203. The use band selection unit 204 refers to the read band information database and uses the use band and the 2.4 GHz band used in the 5 GHz band selected from the 5 GHz band communication band item and the 2.4 GHz band communication band item, respectively. The record 30 corresponding to the combination of used bandwidths is selected. The used band selection unit 204 acquires the value of the communication pattern number from the selected record 30. The used band selection unit 204 outputs the acquired communication pattern number to the communication unit 201. The communication unit 201 transmits a communication pattern number value to the AP 10b, thereby instructing communication using the communication band corresponding to the communication pattern number (step S405).

  The communication unit 101 of the AP 10b receives the value of the communication pattern number from the communication terminal 20b. The used band selection unit 105 refers to the communication pattern number item in the band information database and selects the record 30 corresponding to the received communication pattern number. The use band selection unit 105 acquires each value of the 5 GHz band communication band and the 2.4 GHz band communication band from the selected record 30. The use band selection unit 105 selects each acquired value as a use band used by the own device (communication terminal 20b). Thereafter, the communication unit 101 communicates with the communication terminal 20b using the selected use band (step S406).

  When a certain time has elapsed, the channel scanning unit 206 of the communication terminal 20b performs carrier sense (step S407). The channel scan unit 206 receives a beacon and a packet because there is another AP communicating in the vicinity as a result of the carrier sense (step S408). At this time, the channel scanning unit 206 acquires the RSSI of the received beacon and packet. Further, the channel scanning unit 206 receives a beacon and a packet because there is an AP 10b performing communication as a result of carrier sense (step S409). At this time, the channel scanning unit 206 acquires the RSSI of the received beacon and packet.

  The use band selection unit 204 selects a use band for each frequency band (step S410). Specifically, since there are other communication apparatuses that perform communication in the 2.4 GHz band, the use band selection unit 204 sets a band where the RSSI value is less than the threshold value or a band that is not used. Select the band to be used in the 4 GHz band. In addition, since there is another communication device that performs communication in the 5 GHz band, the use band selection unit 105 uses a band in which the RSSI value is less than the threshold or a band that is not used in the 5 GHz band. Select the band.

  Thereafter, the used band selection unit 204 reads the band information database stored in the band information storage unit 203. The use band selection unit 204 refers to the read band information database and uses the use band and the 2.4 GHz band used in the 5 GHz band selected from the 5 GHz band communication band item and the 2.4 GHz band communication band item, respectively. The record 30 corresponding to the combination of used bandwidths is selected. The used band selection unit 204 acquires the value of the communication pattern number from the selected record 30. The used band selection unit 204 outputs the acquired communication pattern number to the communication unit 201. The communication unit 201 transmits a communication pattern number value to the AP 10b, thereby instructing communication using the communication band corresponding to the communication pattern number (step S411).

  The communication unit 101 of the AP 10b receives the value of the communication pattern number from the communication terminal 20b. The used band selection unit 105 refers to the communication pattern number item in the band information database and selects the record 30 corresponding to the received communication pattern number. The use band selection unit 105 acquires each value of the 5 GHz band communication band and the 2.4 GHz band communication band from the selected record 30. The use band selection unit 105 selects each acquired value as a use band used by the own device (communication terminal 20b). Thereafter, the communication unit 101 communicates with the communication terminal 20b using the selected use band (step S412).

<Modification>
The second embodiment may be modified similarly to the first embodiment.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

10 (10a, 10b) ... AP (communication device), 20 (20a, 20b) ... Communication terminal (communication device), 101 ... Communication unit, 102 ... Channel scan unit, 103 ... Determination unit, 104 ... Band information storage unit, DESCRIPTION OF SYMBOLS 105 ... Use band selection part, 106 ... Transmission signal production | generation part, 107 ... Transmission signal synthesis part, 201 ... Communication part, 202 ... Transmission signal synthesis part, 203 ... Band information storage part, 204 ... Use band selection part, 205 ... Transmission Signal generation unit, 206 ... channel scan unit, 207 ... determination unit

Claims (5)

A use band selector for selecting a band to be used in each of a plurality of frequency bands;
A communication unit that communicates with other communication devices using the selected band;
A communication device comprising:   The communication device according to claim 1, wherein the use band selection unit selects a maximum band in which communication is possible in each of the plurality of frequency bands. A transmission signal generation unit that generates a transmission signal transmitted in each of the plurality of frequency bands;
The transmission signal generation unit, when generating the transmission signal, gives transmission data for a band selected for each frequency band and a transmission number indicating an order of the transmission data to the transmission signal. Item 3. The communication device according to Item 1 or 2. A use band selection step for selecting a band to be used in each of a plurality of frequency bands;
A communication step of communicating with another communication device using the selected band;
A communication method comprising: A use band selection step for selecting a band to be used in each of a plurality of frequency bands;
A communication step of communicating with another communication device using the selected band;
A computer program for causing a computer to execute.

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